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Design and performance of a solar-powered air-conditioning system in a green building
Abstract
A solar-powered adsorption air-conditioning system was designed and installed in the green building of Shanghai Research Institute of Building Science. The system contained 150 m2 solar collectors and two adsorption chillers with nominal refrigeration capacity of 8.5 kW. Based on performance characteristics of the adsorption chiller, the operation mode of the solar-powered air-conditioning system was optimized by maintaining a phase shift of 540 s between the two adsorption chillers. Thereafter, the whole system realized stable operation by the balance of heat consumption and refrigeration output. From June to August of 2005, the solar-powered air-conditioning system continuously ran between 9:00 and 17:00. The operation performance of the system under representative working condition showed that the average refrigeration output of the solar-powered air-conditioning system was 15.3 kW during an 8 h operation and the maximum value exceeded 20 kW. Solar fraction for the system in summer was 71.7%, which corresponded to the designed cooling load (15 kW). Compared with the ambient temperature, it was deduced that solar radiant intensity had a more distinct influence on the performance of solar-powered air-conditioning system.
... The average efficiency of the evacuated tube solar collectors (ETC) is about 36%, if the hot water supplied to the chiller reaches approximately 85°C [89]. Zhai et al. [90] installed a solar-powered, silica gelwater, heat and mass recovery, two adsorption bed air conditioning system. The solar collectors consisted of 150 m 2 of U-type evacuated tubular solar collectors incorporating with compound parabolic collectors and heat pipe evacuated tubular solar collectors. ...
... To perform a regeneration for desiccant material, an air volume flow rate of 10,200 m 3 /h and 100 m 2 of a surface area of the solar collector were used [125]. Table 5 demonstrates some of the solar cooling systems installed after 2001 around the world [82,90,[126][127][128][129][130][131]. The technical information about these systems was mostly accessed from scientific articles, websites, journals and direct contact with manufacturers. ...
... Some of the solar cooling systems installed around the world[82,90,[126][127][128][129][130][131].Liquid desiccant evaporative cooling systemLithium Chloride To ensure the air-conditioning of a chain of offices and a seminar room for air-conditioned area 300 m 2 Desiccant type Silica Gel Air-conditioning of a seminar room and a cafeteria area of the building for air conditioned area 213 m 2 Technological Institute of Canary Islands H 2 O-LiBr single-effect absorption chiller Air conditioning of an office building of 400 m 2 35.2 kW 68,4m 2 flat plate collectors; Two tanks, a 3,000 L hot water and a 1,000 L chilled water storage tanks L' Amor Rouge Bakery, Nicosia, Cyprus Triple effect vapour absorption chiller NPCIL (Nuclear Power Corporation of India Limited), 100 TR manufacturers: Thermax, Pune Office building of S.O.L.I.D., Graz, chiller operation; 2000 L heat storage, 200 L cold storage Résidence du Lac, Maclas, France (2007) Absorption Solar air conditioning system of a building to retired people for air-conditioned area 210 m 2 Solar heating and cooling of the head office building of Vajra with air-conditioned area 670 m 2 ...
The energy demand for cooling and air conditioning systems is increasing worldwide, especially in regions with high solar radiation intensity. One of the reasons for this is the increase of comfort demands worldwide. The most cooling and air conditioning systems are the conventional electrically driven one type such as compression refrigeration machines and air conditioning systems.
Through the huge electricity consumption for cooling and air conditioning, the environmental problems get bigger and bigger, because of carbon dioxide (CO2) and other pollutant emissions.
One of the possibilities to reduce the primary energy consumption is through the use of solar energy for driving the thermal driven absorption or adsorption refrigeration systems, or desiccant cooling. Another possibility is using solar energy to produce electrical energy and this can be used to drive the conventional refrigeration systems.
Many research and developmental efforts in the last years have been done to enforce the spreading of solar-driven cooling systems.
This paper will illustrate the state of the art about the energy consumption for cooling and air conditioning systems, available solar-driven cooling systems and the potential of the utilization of such systems in comparison to the conventional ones. Moreover, this paper highlights some different methods of optimization, which used to maximize the performance and minimize the cost.
... The economic study is summarized in Table 3. A summary of the existing studies for adsorption air-conditioning systems driven by different types of solar collectors is listed in Table 4 [57,90,[112][113][114][115][116][117][118][119][120][121][122][123][124][125]. In these studies, three types of solar collectors (e.g. ...
... Ambient temperature [103] Increase in ambient temperature results in decrease in system COP. [115] CC and solar COP increase slightly as the ambient temperature increases. Chilled water inlet temperature [32] Both CC and COP increase as the chilled water inlet temperature increases. ...
... Summary of existing studies for adsorption air-conditioning systems driven by different types of solar collectors[57,90,[112][113][114][115][116][117][118][119][120][121][122][123][124][125]. ...
... Solar energy, a renewable and clean energy, has been widely used to provide heat and electricity [9]. The use of renewable solar energy to power an air conditioner while reducing greenhouse gas production and energy consumption has attracted global attention [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Numerous researchers have proposed solar energy powered air-conditioning systems, which consist of two types: (1) photovoltaic (PV) conversion, and (2) photothermal conversion [10]. ...
... The proposed system has been simulated in five cities representing four main climate regions, with savings of up to 45% in energy consumption. Zhai et al. [23] designed a solar-powered adsorption air-conditioning system and installed it in a green building. The solar-powered air-conditioning system outputs an average power of 15.3 kW and a maximum power of 20 kW. ...
... Similarly, by comparing Eqs. (23) and (24), the following expression can be obtained. ...
As the greenhouse effect becomes increasingly serious, cooling a vehicle cabin parked under the blazing sun without running the engine or using an electric vehicle’s power has received considerable attention. In this paper, we develop a novel portable, renewable, solar energy-powered cooling system with wireless power transfer (WPT) and supercapacitors to cool the vehicle cabin. The proposed system consists of a solar collector mechanism, an energy conduit, and a temperature control and cooling module. First, consisting of folding solar photovoltaic (PV) panels, the solar collector mechanism making the proposed system portable. Once collected, the solar energy is converted into electricity and stored in the supercapacitors through wireless power transfer without breaching the vehicle body. Automatic temperature regulation is achieved with the cooling device via the temperature control and cooling module. The experimental results indicate that a maximum output power of 2.181 W and a maximum WPT efficiency of 60.3% are achieved when the prototype loaded with 3 Ω and 5 Ω respectively. Meanwhile, the simulation shows the temperature inside the cabin is reduced by as much as 4.2 °C in average, demonstrating that the proposed solar energy-powered cooling system is effective and feasible in cooling a hot vehicle cabin.
... They could be based on a medium temperature heat source like waste heat of the engine or additional fuel burners that are also onboard in some battery-electric vehicles to enable heating without loss of driving range. Next to sorption systems based on silica-gel, zeolites or activated carbon [2][3][4][5], closed metal hydride cooling systems (MHCSs) are a promising technology in this field. As in these systems, hydrogen is the working fluid and they also help to In order to illustrate the detailed working principle of a thermally driven AC system, a schematically van't Hoff plot including two representative equilibrium lines for MH A and MH B is shown in Figure 1 (right). ...
... There exist several studies in the literature, indicating that for thermally driven sorption systems, system optimization strategies are required to increase the achieved thermal power. For example, internal heat recovery or mass recovery options are proposed [2,3,14,15,29]. However, for all of these approaches, either an increased number of MH reactors is required (multi-stage systems) or further valves have to be integrated (heat recovery). ...
Independent of the actual power train, efficiency and a high driving range in any weather conditions are two key requirements for future vehicles. Especially during summertime, thermally driven air conditioning systems can contribute to this goal as they can turn the exhaust heat of internal combustion engines, fuel cells or of any additional fuel-based heating system into a cooling effect. Amongst these, metal hydride cooling systems (MHCSs) promise very high specific power densities due to the short reaction times as well as high reaction enthalpies. Additionally, the working fluid hydrogen has a very low global warming potential. In this study, the experimental results of a compact and modular MHCS with a specific cooling power of up to 585 W kgMH–1referred to one cold generating MH are presented, while reactor and MH weight in total is less than 30 kg and require a volume < 20 dm3. The system is driven by an auxiliary fuel heating system and its performance is evaluated for different operating conditions, e.g., temperature levels and half-cycle times. Additionally, a novel operation optimization of time-shifted valve switching to increase the cooling power is implemented and investigated in detail.
... Thermal cooling technologies are classified as sorption cooling and desiccant cooling. Sorption cooling technologies are increasingly being developed and used because of their simple construction, low operating costs, low temperature heat source and long lifetime (Zhai et al., 2008;McNeil and Letschert, 2007). At present, most of the air-conditioning systems driven by solar energy are based on solar sorption cooling (Zhai and Wang, 2009). ...
... The selection of adsorbent-adsorbate (refrigerant) depends on their physical, chemical and thermodynamic properties as well as their availability and cost (Askalany et al., 2012). Silica gel, zeolites, and activated carbon are usually used as the solid adsorbent with the selection of a suitable adsorbate (refrigerant) for adsorption cooling systems (Zhai et al., 2008). The specific heat capacity and large internal pore structures of activated carbon results in a high capacity to adsorb the adsorbate (Askalany et al., 2012). ...
... Thermal cooling technologies are classified as sorption cooling and desiccant cooling. Sorption cooling technologies are increasingly being developed and used because of their simple construction, low operating costs, low temperature heat source and long lifetime (Zhai et al., 2008;McNeil and Letschert, 2007). At present, most of the air-conditioning systems driven by solar energy are based on solar sorption cooling (Zhai and Wang, 2009). ...
... The selection of adsorbent-adsorbate (refrigerant) depends on their physical, chemical and thermodynamic properties as well as their availability and cost (Askalany et al., 2012). Silica gel, zeolites, and activated carbon are usually used as the solid adsorbent with the selection of a suitable adsorbate (refrigerant) for adsorption cooling systems (Zhai et al., 2008). The specific heat capacity and large internal pore structures of activated carbon results in a high capacity to adsorb the adsorbate (Askalany et al., 2012). ...
This paper presents the comparison of two sorption cooling systems
for providing air conditioning in a residential building that can be driven by a
flat plate solar collector. A thermodynamic model has been developed for each
system to compare the energy balance in each component and the coefficient of
performance (COP). Analyses have been performed for 10 kW water-ammonia
absorption and activated carbon-ammonia adsorption chillers. For both
systems, the first law efficiencies have been compared and the optimum
efficiency has been investigated under different operating conditions. Analysis
revealed that under any operating condition, the COP is always higher for the
absorption chiller and its maximum value is 0.6, which is almost twice that of
the adsorption chiller (COP = 0.35), for 10 kW systems operating at evaporator
and condenser/absorber temperatures of 2ºC and 30ºC, respectively. The
adsorption system requires a higher energy input to produce the same cooling
effect as compared to the absorption system.
... The maximum cooling capacity is observed for the system that operates in Aswan (around 15.8 kW) while the systems operating in Cairo and Jeddah present a maximum refrigerating capacity of around 14.8 kW. Zhai et al. [18] examined the performance of a solar powered adsorption air-conditioning system installed in the green building of Shanghai Research Institute of Building Science. The system comprises two adsorption chillers with nominal capacity 8.5 kW each powered by 150 m 2 of solar collectors. ...
... Finally, for the energy balance in the evaporator the following expression is used: (We,cucpcu + We,wcpw) dTe dt = − LWs dqa dt +ṁ chw cpw T chw,in − T chw,out − − cpw (Tc − Te) Ws dq d dt (17) T chw,out = T e + T chw,in − T e exp − U e A ė m chw c pw (18) The flag in Eqs. (11), (13), (15) and (17) is 0 when the adsorption chiller is in switching mode and 1 when it is in adsorption/desorption mode. ...
Solar driven cooling systems can be a promising alternative to traditional electrical grid powered air conditioning plants. These systems use either thermal or electrical processes to convert solar radiation into cooling. Despite the numerous theoretical and experimental researches that have been carried out in recent years on solar cooling it is still not clear which system presents the best performance. In this study the performance of three different solar cooling systems is examined, namely: 1) a solar electrical, 2) a solar thermal and 3) a hybrid solar electrical-thermal cooling system. The first one system uses PV collectors in order to supply a conventional electrical vapor compression chiller. The second one utilizes thermal collectors in order to power a heat driven adsorption chiller and the third one utilizes PV/T collectors to feed both an electrical and an adsorption chiller. The study is performed for Athens, Greece climatic conditions during an assumed summer period from May to September. The optimum tilt angle of the solar collectors is calculated for maximization of the solar radiation during summer period. It is found to be 14°. The best performance is observed for the solar electrical cooling system utilizing the mono-Si PV modules with a maximum Solar COP of around 0.47 while the lowest is presented by the a-Si PV modules powered cooling system with a minimum Solar COP of about 0.13.
... The results included that COPs of those refrigerants were slightly higher than that of R-22 except R-1270 which was only 0.7% lower than that of R-22. A series of researcher's has studied solar cooling system using absorption refrigeration cycle such as Bong et al [7], Duffy et al [8] and Zhai et al [9]. Another group, like Kunio et al [10], Habib et al [11] works on cooling systems using solar photovoltaic power-based technology. ...
Climate change is a present concern all over the world. In India, in the northern regions of the country, temperatures crossed the 50 degrees Celsius mark. Temperatures in the Indian summer over the last decade or so have repeatedly broken heat records, India was expected to become the world's third largest energy consumer by 2030, overtaking the European Union, contributed by rising incomes and improving standards of living. With the increasing demand for home appliances, the Indian air conditioner market with plenty of room to grow and is estimated to reach 9.7 million units in the financial year 2023. Electricity consumption by room ACs is expected to increase from 8 TWh in 2010 to 239 TWh by 2030. Such growth would have a significant impact on the Indian power sector and would require unprecedented construction of new power plants. We find that 40% of the energy consumed by room ACs could be saved cost-effectively by enhancing their efficiency. This translates to a potential energy saving of 118 TWh at bus-bar or a peak demand saving of 60 GW in 2030. And this energy saving is possible the by implementation of Solar power-based Air conditioners with natural refrigerants. Natural refrigerants used mainly to reduce Global warming potential (GWP) at the same time. This paper indicates the best choice of natural refrigerants R600a & R290 as an organic refrigerant will be preferable for air conditioner among all natural refrigerants analysis by cool pack software for the most wanted domestic 1.5-ton Air Conditioner. Here also, Cool Pack data cross checked with EES Software where both are almost same result reflect here.
... The heat and mass transfer were also interpreted by this model. They studied quantitatively the effect of regeneration temperature on the cooling performance [12]. Parametric analysis studied a two-stage adsorption chiller using reheat demonstrating the effect of the overall thermal conductance and adsorbent mass on system performance [13][14][15]. ...
This study is the second part of the theoretical study of “Modeling and Simulation of a Two-Stage Air-Cooled Adsorption Chiller with Heat Recovery”, which is based on developing a theoretical model for a two-stage adsorption chiller with an activated carbon/methanol pair. The following models were conducted numerically using MATLAB. The model was based on 10th order differential equations; six of them were used to predict bed, evaporator and condenser temperatures, while the other four equations were used to calculate adsorption isotherm and adsorption kinetics. In this second part, bed heat exchangers and evaporator and condenser heat exchangers are studied by varying the parametric design of a chiller. This includes but is not limited to activated carbon mass inside a single bed, overall heat transfer coefficient for the bed and evaporator and the mass flow rates of all components comprising the chiller. The optimum values increased the COP from 0.35 to 0.4, while the cooling capacity was slightly changed. The COP is 95% of a Carnot cycle working at hot water temperatures as low as 60 °C, and 90% at hot water temperatures as high as 90 °C. It was found that the simulation model results for the two-stage air-cooled chiller agreed well with the experimental data in terms of cooling capacity (6.7 kW for the model against 6.14 kW for the experimental result at 30 °C cooling water temperature). The model optimized the adsorption/desorption time, switching time and heat recovery time to maximize both cooling capacity and COP. Moreover, the model is used to study the effect of activated carbon mass, size of beds and mass flow rates of cooling, heating, chiller and condenser on both cooling capacity and COP.
... The heating/cooling effect thus produced, can be used later in a variety of heat pump applications such as the air conditioning of vehicle interiors at the time of discharging or refueling the tank. [3][4][5][6][7][8][9] This work devises a framework to develop and optimize a hybrid FC propulsion source powered by MHTs for transport applications. ...
This paper presents a thermal coupling topology of a proton exchange membrane fuel cell (PEMFC) with a metal hydride tank (MHT) based on FeTi metal hydride (MH) for vehicular applications. Usually, the heat produced by the PEMFC is evacuated to the ambient and MHT is heated by an external heat source, which negatively affects the efficiency of the PEMFC system as a whole. The idea is to reuse the heat generated by the PEMFC and re‐inject it into the MHT to extract the usable hydrogen (H2) for PEMFC. Initially, a comprehensive model of a multiphysics system to manage the exchange of energy flux among the PEMFC and MHT is developed. Subsequently, two distinctive heat exchangers are integrated into the multiphysics system. The performance of the overall system depends on the effective regulation of both temperature and pressure associated with introduced exchanges. For that, two parallel controllers are devised to simultaneously regulate the H2 pressure and temperature of the PEMFC stack. The simulations of the system are established on MATLAB/Simulink software. It is shown by the simulation results that the proposed controller achieves the two requested objectives: maintaining the temperature and pressure of both the PEMFC stack and MHT for reliable operation.
... Zhai et al. [17] experimentally investigated the behavior of a solar adsorption cooling system deployed in the green building of Shanghai Research Institute of Building Science. There are two silica gel/water adsorption chillers in the installation with rated capacities of 8.5 kW each. ...
Heat-driven coolers provide a reliable and environmentally benign alternative to traditional electrically powered chillers. Their main advantage is that they can be driven using low enthalpy heat sources. A solar system is installed at the school of Mechanical Engineering of National Technical University of Athens in order to examine the potential of thermal storage and solar cooling under Athens climatic conditions. The cooling effect is produced using a dual bed, single stage, zeolite/water adsorption chiller with cooling capacity of 10 kW at its nominal conditions of operation. Both vacuum tube collectors and hybrid photovoltaic thermal collectors are installed in order to supply the system with heat. The system is evaluated in terms of solar collectors’ useful energy production, heat stored in the intermediate buffer and cooling system’s performance. It is observed that the cooling system operates satisfactorily under Athens climatic conditions achieving a maximum cooling capacity of 3.7 kW and an average COP around 0.5.
... La fracción solar en verano para este sistema fue del 71,7%, que correspondió a 15 kW de la carga de enfriamiento de diseño. En comparación con la temperatura ambiente, se concluyó que el rendimiento del sistema de aire acondicionado con energía solar está claramente influenciado por la intensidad de la radiación solar (Zhai, 2008). ...
The aim of this paper is to present a general bibliographic review about recent scientific papers focused on the design and operation of air conditioning systems in green and smart buildings.The suggested review is developed using tools offered by the Scopus academic research directory, with a defined search criteria. Furthermore, the VOSviewer science bibliometric analysis software has been used. This paper has several reviews of cooling and heating systems existing or under development available for residential buildings (green and smart buildings) and some initiatives and research projects from recent years. The present paper is an academic research guide for engineers, architects, and students interested in designing, constructing and efficiently managing the cooling processes of green and smart buildings. Economic powers characterized by large megacities of countries such as the United States of America, China, Italy, Malaysia, Germany and Australia; Nowadays, increasing energy efficiency and decreasing carbon footprint of current and future buildings, both green and smart is considered more important. The most frequent fields of research in scientific contributions related to the cooling of green buildings are: sustainable development, energy efficiency and the construction industry; while in smart buildings they are: energy efficiency, smart grids, energy management.
... The main heat sources for adsorption cooling/refrigeration systems are industrial waste heat and solar energy. The systems in which the physical adsorption working pairs employed are usually preferred when solar energy is used as the heat source [3][4][5][6]. The physical adsorption process of the gas occurs mainly within the pores and surface of the solid adsorbent [7]. ...
The objective of this study is to evaluate adsorption characteristics of R134a and R404a on commercially available silica gel samples. A constant volume variable pressure method at different adsorption temperatures ranging from 293 to 323 K and for pressures up to 500 kPa is used in the experimental measurements. Three different type of commercially available silica gel samples were chosen as adsorbent. The isotherms obtained from the experimental measurements were presented. Adsorption parameters were evaluated from the isotherms in order to obtain correlations in the form of the Dubinin-Astakhov (DA) equation. The pressure and temperature dependence of the isosteric enthalpies of adsorption is computed with the evaluation of the measured data and the derived equations. Further, the enthalpy of adsorption data were extracted, and correlations are provided for adsorbent-adsorbate pairs obtained from the combinations of the three different silica gel specimens and two refrigerants. INTRODUCTION Among the thermally driven refrigeration systems, adsorption systems, which can be powered by relatively low temperature renewable energy and waste heat resources, are of great interest and considerable research and development studies have been performed by numerous researchers in recent decades[1, 2]. The main heat sources for adsorption cooling/refrigeration systems are industrial waste heat and solar energy. The systems in which the physical adsorption working pairs employed are usually preferred when solar energy is used as the heat source [3-6]. The physical adsorption process of the gas occurs mainly within the pores and surface of the solid adsorbent [7]. The adsorbed amount and concentration of refrigerant in the pores are strongly dependent on pressure and temperature variations as well as the operating conditions of the system [8]. The design of an adsorption refrigeration system requires the knowledge of adsorption characteristics of the employed adsorbent-adsorbate pair when the temperature and pressure are varying. The isosteric heat of adsorption is a specific combined property of an adsorbent/adsorbate combination. The equilibrium adsorption properties at several adsorbent
... The performance evaluation for various durations of the HC showed that the maximum average cooling power was obtained for HC times between 100 s and 120 s. For an increased duration of 200 s, the average cooling power was reduced by around 15% compared to its maximum value of 820 W. Zhai et al. [12] investigated a solar-powered adsorption system based on silica gel, which was driven by hot water at 88-90 °C. It was demonstrated that the cooling power and the COP increased by 30% and 24%, when the cooling temperature was increased from 15.7 °C to 20.5 °C, respectively. ...
An open cooling system based on metal hydrides is a promising new technology to reutilize the compression work in a hydrogen pressure tank by generating heat or cold. Our first of its kind system consists of two alternately operating plate reactors, which are filled with around 1.5 kg of Hydralloy C2 (Ti Zr V Fe Cr Mn 0.98 0.02 0.41 0.09 0.05 1.46) and coupled to a polymer electrolyte membrane fuel cell. In the present study, an extensive performance investigation for a variation of the main influencing parameters is performed: The electrical fuel cell power and the operating temperatures. Overall, it can be observed that in the entire range of various operating conditions, the fuel cell operation is not affected by the alternately operating H2 desorbing reactors. The variation of the electrical fuel cell power between 1.8 and 7.9 kW results in a maximum average cooling power of 807 W at an electrical power of 7 kW, reaching a specific cooling power of 276 W kgMH-1 . The systems performance decreases with rising ambient temperatures (varied in the range: 24.3–42.3 °C) and decreasing cooling temperatures (varied in the range: 13–25.4 °C) due to increased thermal losses and reduced halfcycle times. Concluding the parameter variations, optimization recommendations are given and the expected performance for an improved system design is derived.
... The technique is also an important determinant of GB implementation. Studies have investigated the cost-benefits of GB techniques (Gabay et al., 2014;Friedman et al., 2014), the utilization of renewable energy resources according to local conditions (Zhai et al., 2008;Khalid et al., 2016), the use of passive design strategies for cost reduction (Li et al., 2014;Chen et al., 2015), the suitability of techniques to local conditions (Jin and Ling, 2015;Dong and Jin, 2013), the promotion and coordination of innovative construction techniques (Kuo et al., 2016;Inyim et al., 2014), etc. ...
Building sector is one of the primary culprits of environmental deterioration and energy consumption. Green building (GB) can be an effective solution to these challenges and has been prioritised by many nations, while the quality of most GBs was still low. Therefore, this paper aims to examine the application of GB techniques. In specific, an empirical study was conducted among 106 GBs in China. Results indicate that both water-saving and site planning categories received the highest achievements, followed by indoor environmental quality and energy-saving, and the material-saving and innovation categories were the most difficult to achieve. The items in site planning, energy-saving and indoor environmental quality clusters that depended more on design techniques could be realised evenly, while the water-saving and material-saving clusters that relied more on materials and equipment witnessed two extremes: one approaching to 100% and one close to zero. There could be an increase in technique achievement from low-quality GBs to high-quality GBs. Nevertheless, the achievements of many items were extremely in both one-star, and two- and three-star groups. Some even witnessed the reduction from the low-quality GBs to the high-quality GBs. A further investigation indicated that the unavailability of GB technique checklist, the impact of economic cost, low technological operability and the unavailability of GB products constrained the GB technique application. The combining impacts of them could further lower the GB technique application. To unlock these barriers, efforts should be made from the perspective of (1) revision and localisation of GB standard, (2) extensive technical support, (3) government regulations and support, and (4) the co-benefits: integration with other programmes. Overall, this paper is of value to improve GB technique application and facilitate the transitions towards higher quality GB agenda.
... The result shows that solar hybrid air conditioning is feasible through high-temperature cooling. Zhai et al. (2008) designed a solar power air-conditioning system for green buildings. Their results clearly shows that the performance of the system under various working conditions, the average up to 8 h and the maximum values obtained up to 20 KW. ...
The main objective of the present study is to develop a solar thermal hybrid variable refrigerant flow (VRF) air-conditioning system and predict energy saving in this system compared to normal VRF air-conditioning system. In R410a based VRF system compressor works partially to increase pressure and temperature up to 27 bar, 55°C from compressor suction pressure and temperature 27 bar, 55°C. Further increase in temperature and pressure from approximate 55°C, 27 bar (Solar heat exchanger inlet) to 80°C, 34.39 bar (Solar heat exchanger outlet) is achieved with the help of evacuated tube type solar collector-based heat exchanger. The calculation of energy saving in solar thermal hybrid VRF system has been compared with fully electric-fired VRF system. The energy saving of approximate 45–50% can be achieved in solar thermal hybrid VRF system as compared to normal VRF system.
... In the literature, there are numerous investigations carried out on the performance of solar-powered adsorption cooling systems. Zhai et al. [23] and, Zhai and Wang [21,22] designed and constructed, in Shanghai, (China), a solar driven cooling system with two small water-silica gel adsorption chillers of 8.5 kW nominal capacity for each powered by an evacuated tube solar collector field of area 150 m 2 . Also, a hot water storage tank of 2.5 m 3 in volume was integrated with the system. ...
The aim of this study is to identify the optimal design parameters of a fully solar-powered adsorption cooling system for residential buildings located in hot arid areas. The proposed system consists of solar collectors, hot water tank, water–silica gel adsorption chiller of 8 kW cooling capacity, cold water tank, fan coil unit, and cooling tower. An optimization based on computer simulation has been conducted for achieving the aim of this study. The proposed system was applied to Assiut, Egypt as a case study. The optimization shows that the optimal design parameters of the proposed system are as follows: 58 m² solar collecting area, 5.5 m³ hot water tank and 1 m³ cold water tank. The simulation of the proposed system with the optimal design parameters during the design day shows that the chilled water temperature leaving the chiller is between 17 and 18 °C with high cooling water temperature of 34.5 °C. This makes the system unable to achieve the indoor thermal design conditions. However, the system is able to meet the cooling demand in most days of the cooling season except for about 9.15% representing extreme hot days. The simulation also shows that during the design day, the proposed system achieves daily solar collecting efficiency of 56% and can produce chilling energy of 113.3 kWh with 7.35 kW energy rate and daily COP of 0.41. In addition, the cold water tank enables the system to extend the operation period for 110 min after switching off the chiller.
... . [49] . , - [50] [51] [52] . , , , ...
... There are intensive research efforts to deploy solar power in air conditioning worldwide to demonstrate that it is practically applicable. Zhai et al [4], have designed and installed a solar powered adsorption air-conditioning system in the building of Shanghai Research Institute of Building Science. The operation performance of the system under representative working condition showed that the average refrigeration output of the solar-powered air-conditioning system was 15.3 kW during an 8 hours operation and the maximum value exceeded 20 kW. ...
... Therefore, energy is not effectively recovered in a few months. Nowadays, a large number of solar heating and cooling systems are used in buildings for proper utilisation of solar collectors throughout the year (Zhai et al. 2007(Zhai et al. , 2008. Thus, use of a Trigeneration system consisting of cooling, heat, and power or CCHP seems logical, although little research has been conducted on solar systems for the last 100 years (Zhai et al. 2009). ...
In today’s world, sustainable sources of power play a big part in clean energy production in remote areas. Obviously, in order to increase the utilization of renewable sources of power in energy systems as well as the combined cycles, an analysis on the operating circumstances of the systems is a prerequisite to enhance the efficiency of these systems. Recently, a large number of studies have proposed thermodynamic cycles that are capable of simultaneously generating cooling, heating, and power (CCHP) by means of a variety of techniques and methods and by applying multi-objective optimization methods. The current research, from a different perspective, aims to conduct a comprehensive review on the studies performed in the field of solar, geothermal or combined sources, and subsequently analyzing the multi-objective evolutionary algorithms to identify the most efficient situation, which satisfy researchers’ needs in order to attain a better performance in their ongoing or future research projects. It is worth noting that multi-objective optimization in these cycles is based on optimizing a thermodynamic function (exergy, thermal efficiency and so on) and an economic function (the cost of consumables, maintenance costs, and so on), with the thermodynamic functions accounting for energy resources. Results of different studies in terms of design parameters, operation process, optimization techniques, and other obtained results are compared. Additionally, a summary of typical performance characteristics and cost for the CCHP systems with different prime movers was presented. Overall results showed that the utilization of combined production systems for cooling, heating, and power is more efficient than simple single objective production systems. Another finding of the research was indicative of the fact that the use of Nano-fluids in solar collectors instead of water increases the heat transfer efficiency and specifically those of SiO2, CuO, AL2O3 and TiO2 lead to high performance.
... [156] Therefore, the majority of solar-powered air-conditioning systems at present are solar absorption or adsorption systems based on solar thermal utilization. Zhai et al. [157] designed and installed a solar-powered adsorption air-conditioning system in the GB of Shanghai Research Institute of Building Science. The average refrigeration output of the solar-powered air-conditioning system was 15.3 kW during an 8-hr operation, and the maximum value exceeded 20 kW. ...
Today governments have faced with challenges in security of energy supply because of fluctuating in prices and unbalance distribution of fossil sources, increasing energy demand, uncertainties in oil and gas supplies arising from geopolitical problems, and global warming. Among different energy consumption sectors, residential and commercial sectors have noticeable energy use with 30% share of energy consumption, in which the share of heating and cooling systems are more than 60%. Therefore, designing and constructing efficient buildings is an important subject for energy and construction studies. This research draws a distinction between green buildings, zero energy buildings, sustainable buildings, and smart buildings, and particularly focus on the concept of ‘greening the buildings’. The common scope and objective of the green buildings are set up in the concept of rating systems, which may be the best sources to learn all there is to know about green buildings in a very limited area. These systems inevitably issues standards and details in regard to design, construction, operation, and maintenance of green buildings. Hence, this paper provides a brief overview of prominent green building rating systems around the world, and then specifically focuses on the recent progresses and innovations in the field of design and construction of green buildings. The research emphasizes that green building is not limited to the design of buildings, but also includes topical areas such as site planning, metrics of balance, system design, and even team design.
... In recent years, some researchers (Assilzadeh et al. 2005;Florides et al. 2002;Zhai et al. 2008) have investigated solar cooling systems to gain more experience in terms of design and operation. Most of these papers focused on modelling, simulation, optimisation and design of sorption cooling system that is the most common commercially available technology. ...
... So in several months, the recovery energy will not be used efficiently. Now many hybrid solar heating has been used in green buildings to make the utilization solar collectors more sufficient in whole year [9]. Thus is can be seen that tri-generation system including cooling, heating and power is more rational utilization mode. ...
Renewable energy, Exergoeconomic, Cogeneration system, Solar power Increasing environmental pollutions and the expense of fossil fuels necessitates employment of efficient instruments and easily producible clean sources as abasic solution to this problem. Cogeneration systems are used for their high performance with a performance of approximately eighty-five percent Cogeneration production system with renewable energy source is the best solution to fuel suitable and high cost Amon all renewable energy sources, use of solar power is of interest. Solar power is the best choice because it's free and clean. This project illustrates the analyzed exergy and eregyeconomic simulations of solar hybrid cycle. Thermo economic and exergoeconomic analysis where used in this research, with exergoeconomic we can analyze cycle cost, payback period and exergy performance. Case study for this project was a building with 480 m² or square meters area in Zahedan, Iran. In this study, a small scale hybrid solar heating, cooling and power generation setup including solar collector, screw expender auxiliary heater, adsorption chiller, etc., was proposed and extensively investigated.
... Schéma du système de climatisation solaire par adsorption (C) : (1) Capteur solaire, (2) Refroidisseur adsorption, (3) Tour de refroidissement,(4) Stockage de l'eau chaude, (5) Ventilo-convecteur(Zhai et al. 2008). ...
In this paper, the feasibility of solar adsorption air conditioning system in the region of
Biskra (Algeria) is studied. The main objective is to give a reflection on the current government
support for electricity bills. A comparison between three air conditioning systems was made by
taking into account economic and environmental constraints: classical mono-split system (A),
classical centralized air conditioning chiller (B) and solar adsorption system (C). In the context of
the current government support for electricity bills, results show that system A is actually the
best choice from the total investment costs, electrical consumption and maintenance point of
view. This is observed even with the gain of the electrical consumption obtained in the case of
solar adsorption air conditioner (C). From an environmental point of view, the system (C) is more
advantageous than the classical systems (A) & (B) especially for its use of the solar energy, its low
electrical consumption, low CO2 emissions and low heat rejected to the outside. It can be
concluded that the current state policy do not encourage the transition to the use of air
conditioning systems operate by renewable energies. Thus, the redirection of the current support
for electricity bills to the support of the investment cost of the solar adsorption air conditioner
(C) will make it more competitive in the Algerian market. In this case, system (C) can replace, in
the long-term, the system (A) used actually.
... Main features: developed by SorTech AG, and it enables to paste the heat exchanger surface with silica gel pellets with the aid of epoxy resin without blocking the entrance pores of the pellets Silica gel-water adsorption chiller developed in SJTU[66] Working pair: silica gel-waterPhoto of the adsorption chiller CC(kW): 15 COP: 0.35 (system) 0.15 (solar) Regeneration temp. ( o C): 85 Solar collector type and area: 90 m 2 of U-type evacuated tube and 60 m 2 of heat pipe evacuated tubular ...
This chapter introduces a comprehensive overview about the principles, challenges and applications of adsorption refrigeration systems (ARSs), as a promising sustainable solution for many of cooling and heating applications. In addition to the features and the basics of ARSs, the following topics have been covered such as characteristics of working pairs, trends in improving the heat and mass transfer of the adsorber; advanced adsorption cycles and performance and operational data of some adsorption refrigeration applications. In some details, the operating range and the performance of ARSs are greatly affected by the employed working adsorbent/refrigerant pairs. Therefore, the study, development and optimum selection of adsorbent/refrigerant pairs, particularly the composite adsorbents, can lead to improving the performance and reliability of ARSs. Regarding the enhancement of heat and mass transfer in the adsorbent bed, two methods are commonly used: one is the development of adsorbents through different coating technologies or new materials such as metal-organic frameworks, and the second is the optimization of the adsorber geometrical parameters and cycle modes. Finally, a brief on some adsorption chillers applications have started to find their share in markets and driven by solar or waste heats.
... Recent years, many researchers had taken the possibility of operating an adsorption chiller with solar energy into account both numerically and experimentally, for example [4][5]. The performance of a solar powered adsorption air-conditioning system, installed in the green building of Shanghai Research Institute of Building Science, was investigated by Zhai et al. [6]. Meanwhile, several researchers had compared the performance of solar thermal cooling systems with solar electrical cooling systems [7]. ...
Cooling system represents a growing market in buildings worldwide, with a particularly significant growth rate observed in commercial buildings. Solar driven cooling system can be a promising alternative to traditional electrical cooling system. It can be used in combination with solar thermal collectors or photovoltaic collectors to release the duty caused by electrical cooling system. In this study, the performance of three different solar cooling systems is examined, namely: 1) a solar electrical, 2) a solar thermal and 3) a traditional electrical cooling system. The first system employs photovoltaic module to drive a conventional electrical chiller. The second system uses solar thermal collectors to drive a heat driven adsorption chiller and the third one utilizes the grid power to feed the electrical chiller. Assessment of life-cycle costs of these three systems are conducted to verify the best option for buildings. A case study in Hong Kong is conducted to assess the three cooling systems.
... In their system, the optimum particle diameter was 0.1-0.25 mm. Zhai et al. 73 did an experimental study on optimization of a solar-powered adsorption airconditioning system. They chose two adsorption chillers to analysis. ...
Phase change material cold storage system could improve the efficiency and stability of the solar-powered air-conditioning system and the building thermal environment. This article is a novel investigation of the phase change materials’ usage in cold storage system and the phase change material cold storage working principles and features that are applied in the different solar-powered air-conditioning systems as cited in the recent publications. This involves phase change material cold storage system, solar-powered air-conditioning system, and the commercial market evaluation. To reduce the intermittent solar energy operation, the energy storage system is quite essential. Currently, the popular method is advanced phase change material cold storage. Using phase change materials in the energy storage systems, the heat exchangers and thermal control systems are the potential techniques. This article also reviewed the phase change material cold storage when applied in the solar-powered air-conditioning system based on the previous study. This article could benefit further research in the solar-powered air-conditioning field as integrated to the phase change material cold storage system and help to understand the commercial market development trend. For further studies, it was suggested that the optimal design of solar-powered cooling system could be employed by phase change material storage/release cooling dynamical control to improve the building thermal environment.
... Moreover, the intensive research efforts to deploy solar power in air conditioning worldwide, demonstrates it is practically applicable. Namely, Zhai et al [3], have designed and installed a solar powered adsorption air-conditioning system in the building of Shanghai Research Institute of Building Science. The operation performance of the system under representative working condition showed that the average refrigeration output of the solar-powered air-conditioning system was 15.3 kW during an 8 hours operation and the maximum value exceeded 20 kW. ...
... In the adsorption refrigeration systems, silica gel is the one of the adsorbent used to adsorb the vapor of the refrigerant and promote its evaporation [5]. The solar energy derived adsorption refrigerators with a silica gel-water pair were investigated and their performance reported by several researcher such as Lu et al. [5], 2 Habib et al. [6], Zhai et al. [7], Lu et al. [8], Alam et al. [9] and Pan et al. [10]. However, this pair requires to work under vacuum conditions. ...
All the opinions and statements expressed in the papers are on the responsibility of author(s) and are not to be regarded as those of the journal of Research on Engineering Structures and Materials (RESM) organization or related parties. The publishers make no warranty, explicit or implied, or make any representation with respect to the contents of any article will be complete or accurate or up to date. The accuracy of any instructions, equations, or other information should be independently verified. The publisher and related parties shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with use of the information given in the journal or related means.
... When the free cooling was used, its contribution reached up to about 70% in some cooling months, while it was about 25% during the five years period of the plant operation. Zhai et al. (2008Zhai et al. ( , 2009a) designed and constructed, in Shanghai, (China), a solar-driven silica gel-water adsorption cooling system with two small silica gel-water adsorption chillers of 8.5 kW nominal capacity for each powered by evacuated tube solar-collector field of area 150 m 2 . In addition, a hot-water-storage tank of 2.5 m 3 in volume was integrated with the system. ...
In this study, an experimental investigation on the performance of a small scale residential-size solar driven adsorption (silica gel-water) cooling system that was constructed in at Assiut University campus, Egypt is carried out. As Assiut area is considered as hot, arid climate, field tests for performance assessment of the system operation during the summer season are performed under different environmental operating conditions. The system consists of an evacuated tube with a reflective concentration parabolic surface solar collector (CPC) field with a total area of 36 m2, a silica gel-water adsorption chiller of 8 kW nominal cooling capacity, and hot and cold water thermal storage tanks of 1.8 and 1.2 m3 in volume, respectively. The results of summer season field test show that under daily solar insolation varying from 21 to 27 MJ/m2, the solar collectors employed in the system had high and almost constant thermal efficiency. The daily solar collector efficiency during the period of system operation ranged from about 50 % to 78 %. The adsorption chiller performance shows that the chiller average daily COP was 0.41 with the average chilling power of 4.4 kW when the cooling water and chilled water temperatures were about 31 ˚C and 19 ˚C, respectively. As the chiller cooling water is cooled by the cooling tower in the hot arid area, the cooling water is at a higher temperature than the design point of the chiller. Therefore, an experiment was carried out using the city water for cooling. The results show that an enhancement in the chiller COP by 40 % and the chilling power by 17 % has been achieved when the city water was 27.7 ˚C.
This research focuses on low carbon dioxide alternatives to air-conditioning systems that use sustainable and low-power drives. This detailed research takes into account a 1 t capacity air-conditioning system using several refrigerants based on vapor compression. Natural refrigerants should be used instead of all-synthetic ones due to their environmentally favorable properties. Using the CoolPack software platform, a comparative analysis was conducted, and it was found out that the natural refrigerants R290 and R600a exhibited promising results in terms of heat removal from the evaporator (Q e (kW)), heat removal from the condenser (Q c (kW)), work done by the compressor (W (kW)) and coefficient of performance when fixed temperatures of 10°C for the evaporator and 50°C for the condenser were maintained. For the refrigerant R600a, superheating at the compressor (inlet) suction by 5°C was necessary to maintain the running cycle within a practical working zone. Given that a 1 t vapor compression cycle air-conditioning system based on R290 has a compressor work consumption of 640 W, the motor power input for a single-phase induction motor will be roughly 1000 W. In contrast, direct-current (DC) motors require about 30% less power (770 W) and can be readily driven by solar photovoltaic systems (DC). Thus, by presenting solar thermal (required for R600a) and solar photovoltaic power (DC) applications for the natural refrigerants R290 and R600a, the present work will contribute to a sustainable environment and demonstrate the capabilities of dependable operation with optimal power usage.
The demand for cooling in India is increasing day by day, which has a significant impact on climate change. Therefore, it is essential to reduce the cooling load demand. The present study has been conducted to explore natural refrigerants-based air-conditioning systems, which can significantly reduce the compressor load This study has also included solar thermal base refrigeration systems that consume less conventional electricity. Simulation tools are used to analyze various refrigerants based on vapor compression type domestic air-conditioning systems with different capacities. The study has also taken into account various climatic zones to determine energy savings in the compressor.
This study investigated the crisis of energy from which Gaza has been suffering over the past years. It ventured to highlight the growing needs for energy and the urging need to use renewable and sustainable sources of energy such as solar thermal energy. Much specifically, it gave much importance to the solar water heater (SWH) as well as the solar air heater (SAH). These two important tools rely on clean and renewable source of energy, and their use in the Gaza Strip would greatly help in bringing about an environmental conservation and sustainable economy. The result obviously shows that both SWH and SAH systems are very suitable for space heating for buildings. The maximum annual heating energy gained is 20360.7 kWh at an inclination angle of the solar collector of 30° for SWH. While for SAH the best value of heating delivered was 19268.9 kWh at a tilt angle of 45°. Besides, the result exposes that the use of SWH and SAH systems can potentially save up to $3461.3 and $3275.7 respectively of energy cost annually. The payback achieved on the investment in SWH and SAH is 4.4 and 4 years respectively. Additionally, the utilization of SWH and SAH systems can ultimately save energy as well as potentially reduce emission of air pollution. For instance, using SWH and SAH can reduce 17306.6 and 16378.57 kg/year of CO2 emissions respectively.
Solar energy converts the renewable energy to increase growth. The development of energy in to generated worldwide. It in the most easy to construct the process of solar air Conditioning systems. The different energy areinvolved into the solar air conditioning to the decreasing current Sources Then using high oil and concern environmental effects have been Controlling. The most comfortable Process of the solar energy system. It we implemented nowadays, increase in progress. we are air Conditioning systems are using in. every building, malls,Colleges industries, flats, etc. solar power air conditioning system is the hot issue to study building energy Consumer. I Then we indoor and outdoor comfort of air Conditioning while be cold storage system. To increasing the efficiency of air Conditioning intensity of the cooling system. The transient thermal efficiency we can using the storage system to maintain the temperature to indoor,The solar system must be using the different. Parabolic collector from the high accommodation,The basic analysis, to investment of Solar air conditioning system are using 3-phase accumulator. The solar energy using of high rate of low grade energy to high grade of energy are Converting them. It will high efficient process could be panels, collectors, will cool the High temperature can be assumed to use the chilled water storage tank. can be provided due to reduce the system of on and off options. There are improving solar system.It will high efficient process could be panels , collectors, will cool the High temperature can be assumed to use the chilled water storage tank. can be provided due to reduce the system of on and off options. There are improving solar system.it is common for the storage chilling water can be utilized, that can to be operated solar energy.
The demand for air conditioning is increasing rapidly in all around the world, this in turn is responsible for the rapid increase in air conditioning, which initiates high demand in consumption of electricity causing increase in the use of fossil fuels and nuclear power, primarily responsible for global warming. In this research work, an attempt has been made between the conventional air conditioning and solar air conditioning system. The CAD (Computer Aided Design) model of the solar air conditioning is made by using fusion 360 software. The room calculations are done through which solar determination and overall performance is evaluated.
In southern Jordan, the ice machine was designed, produced, operated, and fully examined at Mutah University, a unique Nano-coated ammonium/calcium chloride absorption sun unit. Analytical and experimental assessments on the use of ammonia/calcium chloride absorption unit ice produced. The new study has decreased energy emission by the Nano ice-making company while enhancing Nano's ice machine's nuclear power compared to standard solar chiller absorption that is not used in the current research. Our case was the world's first research to examine the effect of a nanoparticle combination of paint on an absorption cooling system used to make ice by the sunlight. The result of the test was quite encouraging. The combination of paint and nanofluid particle materials has boosted the accessibility to sun-based cooling processes and their capability to make ice of absorption. In addition, 0.6 was found to be a pretty good COP for the ammonia/calcium chloride solar system of absorption.
The previously published studies based on the performance prediction of solar-powered adsorption chillers generally incorporate fixed heat/mass recovery (HR/MR) cycle times which remain unchanged during the entire course of operation of the adsorption chiller. In reality, the dynamics of the HR/MR processes are continuously subject to change due to temporal variations in the solar radiation intensity, and thus fixed HR/MR cycle times might not prove to be compatible with the actual dynamics of a transient solar-powered chiller operation. The current study proposes a numerical scheme for performance modeling of a commercial-scale adsorption chiller with adaptive HR/MR cycle times following the adsorption/desorption (ads/des) cycle. A novel model of the MR cycle has been proposed which, according to the best knowledge of the authors, cannot be find anywhere in the previously published literature. The ads/des→HR→MR→des/ads half cycle has been predicted to yield an almost 52% higher cycle-averaged value of coefficient of performance (COP), an almost 16% higher value of specific cooling power (SCP), and a roughly 146% higher value of solarCOP (COPsc) than the ads/des→MR→HR→des/ads half cycle over the entire course of operation of the adsorption chiller till sunset.
The refrigeration and air conditioning systems by adsorption with solar energy are a very interesting option to replace the conventional compression systems because they save energy, are noiseless and use non-aggressive ozone layer refrigerants; however, there are scarcities of studies at this topic. The acquisition of knowledge and positioning in research on this topic by new research groups could be facilitated by knowing the context, trends, and collaborations that emerge in the subject. A map of collaborative co-authors between the greatest authors on the subject was drawn up, the same one that is done using Gephi software. From the analysis of these maps, the centrality degree and collaboration between the authors were determined.
This paper presents research on the annual cooling performance of the solar adsorption heat pump (AHP), which applies a composite natural mesoporous material that is referred to as Wakkanai Siliceous Shale (WSS) as an adsorbent. One way to efficiently employ thermal energy is to reduce the sensible heat loss that occurs when changing the ad/desorption mode by extending the cycle time. The average temperature of the regeneration water for the half cycle time of 14 min was approximately 8.7 °C higher than that for the half cycle time of 8 min. In this case, the system with WSS + LiCl 20 wt% showed an increase in AHP cooling performance of approximately 15%. The higher adsorption capacity of the WSS composite enabled operation of the system with a longer cycle time. In terms of the annual operation of the AHP, although the achievable AHP cooling energy in Dubai was higher than that in Hawaii, much higher cost savings can be obtained in Hawaii than in Dubai because of the high electricity cost in Hawaii. The estimated payback periods in Hawaii and Dubai are 6.6 years and 15.6 years, respectively.
The aim of this paper is to present a general bibliographic review about recent scientific papers focused on the design and operation of air conditioning systems in green and smart buildings.The suggested review is developed using tools offered by the Scopus academic research directory, with a defined search criteria.
Furthermore, the VOSviewer science bibliometric analysis software has been used. This paper has several reviews of cooling and heating systems existing or under development available for residential buildings (green and smart buildings) and some initiatives and research projects from recent years. The present paper is an academic research guide for engineers, architects, and students interested in designing, constructing and efficiently managing the cooling processes of green and smart buildings. Economic powers characterized by large megacities of countries such as the United States of America, China, Italy, Malaysia, Germany and Australia; Nowadays, increasing energy efficiency and decreasing carbon footprint of current and future buildings, both green and smart is considered more important. The most frequent fields of research in scientific contributions related to the cooling of green buildings are: sustainable development, energy efficiency and the construction industry; while in smart buildings they are: energy efficiency, smart grids, energy management.
Keywords: Ecological buildings; intelligent building; cooling system; energy efficiency; biometric analysis; text mining
The present project is an airconditioning system designed to be installed in vehicle. The airconditioning system derives power from solar cell and the electric power is used to drive the electric motor with compressor to produce the cooling. The solar cell is also installed with maximum power point tracking (MPPT) for the battery charger. The system provides a new method of solar driven system together with the existing power system in a vehicle. Invention provides a method to work with the existing system based on retrofitting and without deteriorating the overall performance and affecting other components.
Performance assessment of a two-bed silica gel-water adsorption refrigeration system driven by solar thermal energy is carried out under a climatic condition typical of Perth, Australia. A Fourier series is used to simulate solar radiation based on the actual data obtained from Meteonorm software, version 7.0 for Perth, Australia. Two economic methodologies, Payback Period and Life-Cycle Saving are used to evaluate the system economics and optimize the need for solar collector areas. The analysis showed that the order of Fourier series did not have a significant impact on the simulation radiation data and a three-order Fourier series was good enough to approximate the actual solar radiation. For a typical summer day, the average cooling capacity of the chiller at peak hour (13:00) is around 11 kW while the cyclic chiller system coefficient of performance (COP) and solar system COP are around 0.5 and 0.3, respectively. The economic analysis showed that the payback period for the solar adsorption system studied was about 11 years and the optimal solar collector area was around 38 m2 if a compound parabolic collector (CPC) panel was used. The study indicated that the utilization of the solar-driven adsorption cooling is economically and technically viable for weather conditions like those in Perth, Australia.
Thermal energy storage is essential to the operation of many systems. It plays a vital role in many renewable and CO2-reducing technologies which have a mismatch in time between when thermal energy is available and required. Water is the most commonly used thermal storage medium in many applications, however, for systems with a small temperature operating range, large storage volumes may be required since the energy storage capacity of water is proportional to the temperature range. In contrast, phase change materials (PCMs) can maintain high energy capacity under limited temperature conditions, but they typically have low thermal conductivities which results in slow melting/solidification rates. As such, careful design of the encapsulation geometry is required to take advantage of phase change thermal storage. Systems using phase change materials must ensure complete melting, and the encapsulation thickness must be designed according the system needs.
Models of hybrid storage tanks employing both water and PCM are investigated, with PCM encapsulations embedded in water. This study uses a novel application of analytical formulations of 1-D melting to size rectangular PCM encapsulation to match the requirements of a residential heat pump system. With boundary conditions that reflect the heat pump and storage characteristics, the proposed analytical solution links encapsulation thickness to system requirements. The analytical formulation is derived for encapsulation thickness in terms of heat pump rating, temperature differential, storage material, and storage volume. The solution was verified through system-level numerical simulations using TRNSYS and an in-house enthalpy-porosity modeling tools detailed in the paper. The verifications have shown a good agreement, and the melt thickness predictions were within 4% between both models. The study proposes using the methodology as a standard for designing hybrid water-phase change material thermal storage for heat pumps, which can be expanded to various PCM geometries and thermal systems.
High pressure storage of hydrogen is the established storage technology for automotive systems. However, around 15% of the lower heating value of hydrogen is spent to compress hydrogen up to the pressure of 700 bar. Since this energy is available on board but so far wasted, an open air-conditioning system based on metal hydrides is promising to reutilize this compression work. Here we present the experimental demonstration of a first of its kind system. The setup consists of two alternately operating plate reactors, each filled with around 1.5 kg of Hydralloy C2 (Ti0.98Zr0.02V0.41Fe0.09Cr0.05Mn1.46), coupled to a polymer electrolyte membrane fuel cell. The demonstration at an electrical power of 5 kW shows that the fuel cell operation is not affected by the alternately H2 desorbing reactors (half-cycle duration of 150 s). The system’s average cooling power was 662 W for an ambient temperature of 30 °C and a cooling temperature of 20 °C, reaching of specific cooling power of 227WkgMH-1. Related to the maximum obtainable cooling power of 18.3% of the electrical fuel cell power, the cooling efficiency corresponds to 75%. As an innovative hydrogen pressure transducer the presented system can be transferred to all applications where an unused hydrogen pressure difference is available.
The objective of this work is studying the opportunity of using a Solar Heating System, SHS, to prevail the Tunisian households’ air-heating needs by comparing the energetic performances of two solar heating technologies: the SHS with an integrated active layer in the floor and a SHS with an integrated active layer in the wall. The SHS mainly consists of flat-plate solar collectors, a hot water cylinder and an active layer integrated inside the heated building. The study is accomplished by means of TRNSYS 16 simulation software. The investigations of the energetic and thermal performances of the SHS were based on an experimental and simulation studies. A complete model is formulated by means of the TRNSYS simulation program. To validate the TRNSYS model, experimental tests under the typical North-African climate (Tunisia) was performed. The optimization of the SHP performances was achieved by considering the monthly/annual solar fraction, SF. Then, we evaluate the long-term performances of the solar heating system with an integrated active layer in the floor and a solar heating system with an integrated active layer in the wall. The results showed that the optimal sizing of the heating system that allows the supply of a maximum rate of the solar fraction consisted on using 6 m² area of solar collector, a collector’s mass-flow rate of about 120 kg h⁻¹, a hot water storage cylinder with a capacity of 450 L and a mass flow-rate inside the active layer about 300 kg h⁻¹. The comparison of the long-term performance of the solar heating system showed that the use of the floor as a heat source presented a great potential with a solar fraction of about 78%. It was also found that the use of the solar heating system, SHS, reduced obviously the relative humidity inside the tested room of about 35%.
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Perennial Efforts to combat power crises in newly found Telangana state, compelled to use hybrid source of power which is being catered to facilitate the needs of modern trends, life style, multinational business requirements which enforced the need to explore the modern application of solar energy run household and administrative block. Air conditioning requirement, which consumes more than 30% of the state procured power from different sources, which can be save and utilize for agriculture sector and other constructive needs.
In Telangana State every commercial, administrative and elite residential block is equipped with air conditioning system where the temperature ranges between 32-43<sup>0</sup>C in summer season. Telangana State is attracting the world class business investors. This design can caters the world class needs therefore this paper explore the design and performance of solar power air-conditioning system, which is integrated with invertors, PV panels, solar charger and batteries. This design can be used in non-electrified rural arid areas to avoid the expenses of supplying electricity.
This research project begins with the cooling load calculations for the selected space ideally whose dimensions are assumed to be one tone of refrigeration (3.5kW). Considering the basic parameters of cooling the photovoltaic cells has been deduced and necessary connections are arranged.
To acquire the inlet and outlet temperatures of compressor, evaporator and condenser, data logging procedure is employed. The input power for this system as well as coefficient of performance for above said climatic conditions can be deduced. The COP varies from two to four for this system and these results are compared with the convectional system performance they both match with each other considerably.
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Tools and experience on solar thermal cooling system sizing and design are still limited, as less than one thousand plants have been built until now. In this paper, a design tool for mid-size thermal solar cooling systems is presented. The tool consists of a model realised in TRNSYS and validated using the data of a real solar air conditioning system installed in the green building of Shanghai Research Institute of Building Science. Characteristic features of the system are the use of adsorption chillers driven by low-temperature solar heat from U-type and heat pipe evacuated solar collectors. The model has subsequently been employed for a technical analysis: the most relevant parameters have been varied and figures of merit calculated. An energy analysis has been performed for 6 reference cities, differing for climates and latitudes, highlighting the possibility to use only renewable energy for cooling purposes. Eventually, the systems have been compared with reference ones. Comparison highlighted that considerable savings in primary energy and CO2 emissions can be achieved: 0.97 MWh per installed square meter of solar collectors and up to 22 tons of CO2 annually, thus indicating a great potential for increasing energy efficiency and reduce CO2 emissions.
In economics, normative utility theories of decision-making under risk use a single number (expected value) to index subjective utility at the cost of losing information about risk distribution. This paper examines how people make use of risk distributions (that is, variations in expected payoffs) to maximize the probability of reaching a goal and to minimize the likelihood of falling below a minimum requirement (MR). The author proposes and tests a Bounded Risk Distribution model using both hypothetical life-death problems and real reproductive and parental decision problems. Study 1 demonstrated that a given degree of increase in expected number of saved lives had a significant effect on the respondents' risk preference when the increase was likely to cross the average MR of the respondents (in a small group context), but the same increase in expected value had little effect when the change was within a range below the average MR (in a kinship context) or above the MR (in a large group context). Study 2 examined alternative hypotheses for hypothetical risk acceptance with respect to kinship groups and found that whether the decision-maker was responsible or not had little effect on the setting of the MR and risk preference. The MR setting was mainly determined by the kinship context itself and was further fine-tuned by the framing of the choice outcomes. Study 3 was conducted in four rural villages in northwest China, and assessed real reproductive decisions. Interbirth intervals but not breastfeeding duration varied with a family's wealth, the sex of a child, and the perceived resemblance of a child to a parent. These results are interpreted in terms of the same Bounded Risk Distribution model that was applied in the hypothetical scenario studies.
This paper is the second part of a study on the use of adsorption refrigeration cycles driven by waste heat of near-ambient temperature. Experiments were conducted with several heat transfer fluid operating temperatures (hot, cooling, and chilled water), flow rates, and adsorption-desorption cycle times, and good qualitative agreement was obtained with the simulated results. Both experiments and simulation showed that the silica gel-water adsorption cycle is well suited to near-environmental-temperature heat sources and small regenerating temperature lifts, which help reduce the heat losses intrinsic to batched cycle operation. The chiller was operational with a hot water inlet temperature (Thot in) of 50°C (122°F), and the highest experimental values of the coefficient of performance (COP) (more than 0.4) were obtained with Thot in = 50°C (122°F) in combination with cooling water at 20°C (68°F).
Energy efficiency in building is an important part of energy efficiency movement launched in China, From technical point of view, the energy efficiency of HVAC and the integrated use of energy in buliding were discussed. The energy saving measures and some hybrid energy systems at home and abroad were introduced. Energy Plus software for simulation of hybrid energy systems was described. Energy consumption in building was analyzed.
This paper reports on the performance of a solar powered absorption air conditioning system with a partitioned hot water storage tank. The system employs a flat-plate collector array with a surface area of 38 m2 to drive a LiBr–H2O absorption chiller of 4.7 kW cooling capacity. The system is provided with a storage tank (2.75 m3) which is partitioned into two parts. The upper part has a volume of about one-fourth of the entire tank. The performance of this modified system is presented and compared with the conventional system design (whole-tank mode). The study reveals that the solar cooling effect can be realized nearly 2 h earlier for the system operating in partitioned mode. In this system a total solar cooling COPsystem of about 0.07, which is about 15% higher than with traditional whole-tank mode, is attained. Experimental results also show that during cloudy days, the system could not provide a cooling effect, when operated conventionally, however in the partitioned mode-driven system the chiller could be energized, using solar energy as the only heat source.
The research work on adsorption refrigeration in Shanghai Jiao Tong University (SJTU) started in 1993, various adsorption refrigeration cycles have been investigated, such as continuous heat recovery cycle, mass recovery cycle, thermal wave cycle, convective thermal wave cycle, cascade multi effect cycle, hybrid heating and cooling cycle etc. Several prototype adsorption refrigeration systems have been developed and tested, typical examples are continuous heat regenerative adsorption ice maker using spiral plate adsorbers, adsorption heat pump using novel heat exchanger as adsorbers, solar powered adsorption ice maker, solar powered hybrid system of water heater and adsorption refrigerator, waste heat driven air conditioning system for automobiles. Reasonable experimental results have been obtained, it was found that with a heat source temperature of 100°C, the refrigerator can obtain specific refrigeration power for 5.2 kg-ice/day per kg activated carbon in one adsorber, the heat pump can reach a specific cooling power for more than 150 W/kg-adsorbent with a COP close to 0.5, the adsorption solar ice maker yields 5-7 kg-ice per day per square meter solar collector, the hybrid solar water heater and ice maker is capable of heating 60 kg water up to about 90°C and meanwhile yields ice making about 5 kg per day with a 2 m2 solar collector. The adsorption mechanisms of adsorption refrigeration pairs and also the thermo-physical properties have been also studied in SJTU, which are very helpful for adsorption refrigeration researches. This paper shows the various aspects researched in SJTU.
An environmental control system utilizing solar energy would generally be more cost-effective if it were used to provide both heating and cooling requirements in the building it serves. Various solar powered heating systems have been tested extensively, but solar powered air-conditioners have received little more than short-term demonstration attention. This paper reviews past efforts in the field of solar powered air-conditioning systems with the absorption pair of lithium bromide and water. A number of attempts have been made by researchers to improve the performance of the solar applied air-conditioning (chiller) subsystems. It is seen that the generator inlet temperature of the chiller is the most important parameter in the design and fabrication of a solar powered air-conditioning system. While collector choice, system design and arrangement are other impacting factors for the system operation.
The primary objective of this review is to provide fundamental understandings of the solar adsorption systems and to give useful guidelines regarding designs parameters of adsorbent bed reactors,and the applicability ofsolar adsorption both in air-conditioning and refrigeration with the improvement of the coefficient of performance. Solar adsorption heat pump and refrigeration devices are of significance to meet the needs for cooling requirements such as air-conditioning and ice-making and medical or food preservation in remote areas. They are also noiseless, non-corrosive and environmentally friendly. For these reasons the research activities in this sector are still increasing to solve the crucial points that make these systems not yet ready to compete with the well-known vapor compression system. There is an increasing interest in the development and use of adsorption chillers due to their various economic and impressive environmental benefits, enabling solar energy or waste heat to be used for applications such as district networks and cogeneration plants. Compared to adsorption systems that require heat sources with temperatures above 100°C (zeolite-water systems, activated carbon-methanol systems) or conventional compressor chillers, a silica gel/water adsorption refrigerator uses waste heat with temperature below 100°C. This creates new possibilities for utilizing low temperature energy.
This review centers on the status, and future directions of the cell and module technologies, with emphasis on the research and development aspects. The framework is established with a consideration of the historical parameters of photovoltaics and each particular technology approach. The problems and strengths of the single-crystal, polycrystalline, and amorphous technologies are discussed, compared, and assessed. Single- and multiple junction or tandem cell configurations are evaluated for performance, processing, and engineering criteria. Thin-film technologies are highlighted as emerging, low-cost options for terrestrial applications and markets. Discussions focus on the fundamental building block for the photovoltaic system, the solar cell, but important module developments and issues are cited. Future research and technology directions are examined, including issues that are considered important for the development of the specific materials, cell, and module approaches. Novel technologies and new research areas are surveyed as potential photovoltaic options of the future.
A simple lumped parameter model is established to investigate the performance of a solar powered adsorption air conditioning system driven by flat-type solar collectors with three different configurations of glazes: (i) single glazed cover; (ii) double glazed cover and (iii) transparent insulation material (TIM) cover. The dynamic performance of a continuous adsorption cycle using a double adsorber along with heat recovery is measured in terms of the temperature histories, gross solar coefficient of performance and specific cooling power. Also, the influences of some important design and operational parameters on the performance of the system are studied. It is found that the chosen three types of collector configurations make no big difference on the performance, but the adsorbent mass and lumped capacitance have significant effects on the system performance as well as on the system size. Simulation results indicate that the effect of overall heat transfer coefficient is not predominant if the cycle duration is longer. Also, there exists an optimum time to initiate the heating of the adsorbent bed in a day's operation.
Shanghai is characteristic of subtropical monsoonal climate with the mean annual temperature of 17.6 °C, and receives annual total radiation above 4470 MJ/m2 with approximately 2000 h of sunshine. A solar energy system capable of heating, cooling, natural ventilation and hot water supply has been built in Shanghai Research Institute of Building Science. The system mainly contains 150 m2 solar collector arrays, two adsorption chillers, floor radiation heating pipes, finned tube heat exchangers and a hot water storage tank of 2.5 m3 in volume. It is used for heating in winter, cooling in summer, natural ventilation in spring and autumn, hot water supply in all the year for 460 m2 building area. The whole system is controlled by an industrial control computer and operates automatically. Under typical weather condition of Shanghai, it is found that the average heating capacity is up to 25.04 kW in winter, the average refrigerating output reaches 15.31 kW in summer and the solar-enhanced natural ventilation air flow rate doubles in transitional seasons. The experimental investigation validated the practical effective operation of the adsorption cooling-based air-conditioning system. After 1-year operation, it is confirmed that the solar system contributes 70% total energy of the involved space for the weather conditions of Shanghai.
A solar-powered air-conditioning system was designed, installed and operated in Singapore. The system made use of 32 m2 of heat-pipe collectors and a lithium bromide-water absorption chiller of 7 kW cooling capacity. The operation of the system was fully automated. The dynamics of its daily operation and its weekly energy performance is presented. The chiller operation is described by the relationship between its solar and auxiliary heater contributions. The performance of the system over a representative local insolation condition is compared with the reported performances of two systems operating in the USA.
An improved lumped parameter model has been developed to predict the dynamic performance of adsorption cycles with a single and/or double adsorber with heat recovery. The mathematical formulation of this model is based on the conservation equations and the isosteric equation of state. Several constitutive relationships have been integrated into the model to enhance its capability to predict the thermal phenomena taking place inside the adsorber and the heat exchangers. New submodels have been added to predict the performance of air-cooled evaporator and condenser-type heat exchangers. Numerical results compared to experimental data on single and/or double adsorbers with heat recovery, indicate that the model predicts the dynamic performance of adsorption systems well, and compares well with the experimental data.
Development of a silica gel–water adsorption chiller and study of the characteristics of adsorption systems driven by variable heat source PhD dissertation of Shanghai Jiao Tong University
- Dc Wang
Wang DC. Development of a silica gel–water adsorption chiller and study of the characteristics of adsorption systems driven by variable heat source. PhD dissertation of Shanghai Jiao Tong University; 2005. X.Q. Zhai et al. / Applied Energy 85 (2008) 297–311 311
An improved model for predicting the dynamic behaviour of adsorption systems Fig. 18. Variations of the performance of solar-powered adsorption air-conditioning system with average ambient temperature
- Sm Sami
- Tribes
Sami SM, Tribes C. An improved model for predicting the dynamic behaviour of adsorption systems. Appl Therm Eng 1996;16:149–61. Fig. 18. Variations of the performance of solar-powered adsorption air-conditioning system with average ambient temperature. 310 X.Q. Zhai et al. / Applied Energy 85 (2008) 297–311
18. Variations of the performance of solar-powered adsorption air-conditioning system with average ambient temperature
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Fig. 18. Variations of the performance of solar-powered adsorption air-conditioning system with average ambient temperature.
Development of a silica gel-water adsorption chiller and study of the characteristics of adsorption systems driven by variable heat source
- D C Wang
Wang DC. Development of a silica gel-water adsorption chiller and study of the characteristics of adsorption systems driven by
variable heat source. PhD dissertation of Shanghai Jiao Tong University; 2005.