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Increasing awareness of global warming forces policy makers and industries to face two challenges: reducing greenhouse gas emissions and securing stable energy supply against ever–increasing world energy consumption, which is projected to increase by 71% from 2003 to 2030. In addressing these two issues simultaneously, renewable energies prove them...
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... τ ' 1 and τ ' 2 without sun. The integral equation (14) can be solved when the meteorological data are known. At the same time one considered the day like a sum of f×N hours with sun and (1-f×N) hours without sun. Taking into consideration this simpliffy supposition, to calculate the effective solar energy, the following cases should be analyzed (Fig. 16): ...
Context 2
... 1 and τ ' 2 without sun. The integral equation (14) can be solved when the meteo- rological data are known. At the same time one considered the day like a sum of f×N hours with sun and (1-f×N) hours without sun. Taking into consideration this simpliffy sup- position, to calculate the effective solar energy, the following cases should be analyzed (Fig. 16): ...
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... Conventional solar collectors face the thermal losses of hot water generated from solar energy, as hot water in the storage tank may radiate all its thermal energy to the surroundings [34,35]. Also, extensive industrial facilities (like pharmaceutical factories) and commercial buildings cannot rely only on conventional flat plat collectors or ETSC to provide continuous hot water (24 hr/7 days). ...
This research is carried out to investigate and examine the critical benefits and significant contributions of integrating nanoparticles into the ETSC system to enhance the thermal efficiency, thermal performance, temperature out, and energy storage of the ETSC. The Simcenter STAR-CCM+ 2022.1 software package implemented numerical analysis and thermal simulations. Further, a comparative analysis is conducted on two case studies to validate the critical role and contributions of employing the aluminum oxide nanomaterial in the solar collector system to enhance its thermal efficiency and improve its thermal performance and heat transfer, including (1) conventional ETSC and (2) ETSC with Al2O3. According to the numerical analysis and comparative study findings, the results of this research revealed that employing and adding the aluminum oxide nanomaterial into the ETSC system had contributed to several beneficial impacts and significant advantages. In addition, using Al2O3 achieved enhancements in the thermal efficiency, increases in the outlet collector's temperature, improvements in the rate of heat flux of the pipes, the tube inside the collector, heat transfer of the hot water storage tank, and a rise in the temperature gradient the hot water temperature increased from (between 44.3 and 74.8 ºC) to (between 49.6-80.3 ºC). Besides, the velocity of the water flow inside the solar collector in the second case in which the aluminum oxide nanoparticles are used was higher due to the absorption of further solar radiation and thermal energy, which resulted in a considerable increase in the kinetic energy of water molecules from 0.01 to 0.07 m/s. Also, it was found that the velocity directions and profile were slightly more turbulent in the second case than the conventional solar collector due to more thermal energy absorbed and stored in the ETSC from solar radiation.
... There are several ST collectors available on the market [26]. Generally, a system for transforming solar energy to thermal energy consists of the following components ( Figure 4): solar collectors (panels); heat storage schemes; circulating pumps; a heat transmission and distribution network; and automation, control, and safety equipment [50]. This system can provide heat for space heating and DHW production. ...
This article presents a complex and exhaustive review of the integration of renewable energy sources (RES) (specifically solar, geothermal, and hydraulic energies and heat pumps (HPs) and the improvement of water pumping in district heating systems (DHSs) focused on low-temperature systems, to increase energy efficiency and environmental protection. For this aim, the main components of a DHS and the primary RES with applications in DHSs are described briefly. Finally, several case studies regarding the DHS in Timisoara, Romania, are analysed. Thus, by integrating water source HP (WSHP) systems in cooperation with solar thermal and photovoltaic (PV) collectors and reducing the supply temperature from 110 °C to 30 °C in DHS, which supplies the water radiators to consumers in a district of this city in a 58/40 °C regime of temperatures and produces domestic hot water (DHW) required by consumers at 52 °C, a thermal energy saving of 75%, a reduction of heat losses on the transmission network of 90% and a diminution of CO2 emissions of 77% were obtained. Installed PV panels generate 1,160 MWh/year of electricity that is utilised to balance the electricity consumption of HP systems. Additionally, mounting pumps as turbines (PATs) for the recovery of excess hydraulic energy in the entire heating network resulted in electricity production of 378 MW, and the variable frequency drive's (VFD) method for speed control for a heating station pump resulted in roughly 38% more energy savings than the throttle control valve technique.
... Konsumsi energi dunia yang semakin meningkat menciptakan kebutuhan mendesak untuk menemukan cara baru untuk menggunakan sumber energi dengan cara yang lebih efisien dan lebih rasional, diperkirakan konsumsi energi global akan meningkat sekitar 71% dari 2003 sampai 2030 (Sarbu & Adam, 2011;Sarbu & Sebarchievici, 2013). ...
Artikel ilmiah ini membahas hasil evaluasi kinerja mesin pembuat es bertenaga surya di TPI Kramat, pesisir Lampung Selatan. Mesin pembuat es yang dievaluasi adalah memiliki kapasitas 105-120 kg es/jam, 9 panel surya 200 WP yang dipasang pada frame yang berukuran 43 m x 30 m x 27 m, dan baterai 200 AH sebanyak 4 buah. Evaluasi kinerja dilakukan selama bulan November 2016 hingga Februari 2017. Hasil penelitian menunjukkan bahwa terdapat hubungan antara intensitas radiasi matahari (x1) dan suhu udara harian (x2) dengan produksi es (y) di TPI Kramat, Lampung Selatan. Pada bulan November 2016, peralihan musim kemarau ke musim penghujan, hubungan ini dinyatakan dengan persamaan regresi y = 93,2 + 0,04 x1 – 3,28 x2. Pada bulan Desember 2016, awal musim penghujan, hubungan ini dinyatakan dengan persamaan y = 8,42 + 0,006 x1 + 0,004 x2. Pada bulan Januari 2017, puncak musim penghujan, hubungan ini dinyatakan dengan persamaan y = -6,608 – 0,004 x1 + 0,752 x2. Pada bulan Februari 2017, akhir dari musim penghujan, hubungan ini dinyatakan dengan persamaan y = 19,16 + 0,003 x1 – 0,289 x2. Produksi es pada musim penghujan ada indikasi penurunan namun masih bisa mencukupi kebutuhan nelayan.
... Building cooling using air-conditioners became the largest consumer of electricity. More than half of the urban peak load of energy which accounts for nearly 60% of nation's peak power demand is consumed to satisfy air conditioning demands [2]. However, fossil fuels, the current main energy source, are being consumed in a random increasing manner, even though they are non-renewable and their global quantity is limited [3][4][5]. ...
The rate of increase in energy consumption and high costs in addition to the depletion of existing resources has a significant impact on our standard of living for next generations. In this case, the priority is to develop alternative cost-effective sources for powering the residential and non-residential buildings. This paper proposes and develops a design of a modified small two-story residential solar house for a medium-sized family located in Cairo, Egypt. This modified solar house meets almost all its energy demands including space heating by using solar air collector with a pebble storage unit in winter and a summer cooling system using wind catcher theory. Hot water is obtained throughout the day by using a steel sheltered water storage tank with a capacity of 1000 liter. Finally, the proposed heating system of the solar house is sized and modeled.
... Among the energy sources alternative to fossil fuels, renewable energy sources such as solar and wind garner the public's attention, as they are available and have fewer adverse effects on the environment than do fossil fuels. [9]. Thermal energy obtained from the sun with a solar thermal system can be used for domestic water heating, and heating or even cooling of buildings. ...
This work concerns with the investment of solar power to run water coolers. Four water coolers with 20 liters operational capacity are used for eight hours. It was a design calculations required to set up a full solar system. And have been performed calculations design in two stages to get the desired results, the first theoretical and that on the basis of which require the construction of the solar system, solar panels number six with a capacity of 100 watts and four inverters capacity of 1000 watts with 12 volts as parts mainly effective with the controllers of charging and battery with container number four In order to run the system. But that did not happen and did not operate the system, only third hour later got a hard landing.The second is experimental design process and that on the basis of which require the construction of the solar system solar panels are eight with capacity of 100 Watts and four inverters capacity of 1000 watts with 24 volts as parts effective principally with the controllers of charging and battery container with the number four, which gave the functioning effectively for eight hours and achieve the desired results of this research, which it installed on the surface of renewable energies technology center in University of Technology. In order to discuss the main factors affecting the solar panels the following parameters should be measured such as the output power, the ability of output flow and the surface temperature, and the efficiency of photoelectric conversion and working hour. Where the measuring devices are available in the lab of energy and renewable energies technology centre in University of Technology. 1.Introduction Solar cell is the core component of photovoltaic power generation system. The photoelectric conversion efficiency of a solar cell is about 6-17% in commercial application [1]. Most of the radiation has been converted into heat, which results in high temperature of the solar cell and low efficiency. According to Weng et al [2], the temperature increase of 1K corresponds to the reduction of the photoelectric conversion efficiency by 0.2%-0.5%. In addition, long-term high temperature of the solar cell will shorten its service life. Therefore, solar cell cooling is of essential importance. Water-cooling methods are both commonly used in solar cell cooling [2-4]. Thermal tube cooling is deemed to be a promising cooling technology [5-7]. Encountered by the successful world wide effort to protect the ozone layer, scientists and engineers have been committed to minimize and reverse the harming environmental effects of global warming. Global warming occurs when carbon dioxide, released mostly from the burning of fossil fuels (oil, natural gas, and coal) and other gases, such as methane, nitrous oxide, ozone and water vapor, accumulate in the lower atmosphere. As results of the rapid growth in world population and the economy, especially in developing countries, total world energy consumption has increased and is projected to increase by 71% from 2003 to 2030 [8]. Fossil fuels continue to supply much of the energy used worldwide, and oil remains the primary energy source. Therefore, fossil fuels are the major contributor to global warming. The awareness of global warming has been intensified in recent times and has reinvigorated the search for energy sources that are independent of fossil fuels and contribute less to global warming. Among the energy sources alternative to fossil fuels, renewable energy sources such as solar and wind garner the public's attention, as they are available and have fewer adverse effects on the environment than do fossil fuels. [9]. Thermal energy obtained from the sun with a solar thermal system can be used for domestic water heating, and heating or even cooling of buildings. Solar domestic hot–water systems prevail because the hot–water requirement can be well covered by the solar energy offer. Air–conditioning systems are the dominating energy consumers in buildings in many countries, and their operation high electricity peak loads during the summer [10]. The solar cooling technology can reduce the environmental impact and the energy consumption issue raised by conventional air–conditioning systems.The solar thermal energy and its use for building heating and domestic hot–water (DHW),have been described and performed an energetically analysis of the solar heating systems. Also, this paper provides a review of the available cooling technologies assisted by solar energy and their recent advances. The sun radiates considerable energy onto the earth. Putting that diffuse, rarely over 950 W/m 2 work energy has led to the creation of many types of devices to convert that energy into useful forms, mainly heat and electricity. Worldwide, solar energy use varies in application and degree. In China and, to a lesser extent, Australasia, solar energy is widely used, particularly for water heating. In Europe, government incentives have fostered use of photovoltaic and thermal systems for both domestic hot–water and space heating. In the Middle East, solar power is used for desalination and absorption air–conditioning. Solar energy use in the United States is relatively modest, driven by tax policy and utility programs that generally react to energy shortages or the price of oil [11]. The equipment technology for building solar heating systems is
... The ever increasing world-wide energy consumption has created an urgent need to find new ways to use the energy resources in a more efficient and rational way. It is estimated that the global energy consumption will increase by 71% from 2003 to 2030 [10,11]. In addition, 80% of the energy currently used on Earth is generated from fossil fuel resources [12]. ...
... En los sistemas de enfriamiento termo-eléctricos la energía generada por los módulos fotovoltaicos es usada como fuente de alimentación para el enfriamiento del espacio deseada a partir de celdas Peltier, las cuales realizan el enfriamiento a través del principio de efecto termoeléctrico [2, 12]. Entre las ventajas que presentan este tipo de sistemas están que: a) no presentan partes móviles, b) no operan con refrigerantes y c) que pueden ser demasiados pequeños. ...
En las últimas décadas la energía se ha convertido en un tema crucial debido al acelerado incremento en su demanda , misma que se estima aumentará un 71% entre el 2003 y 2030. La principal fuente de generación de energía en la actualidad se da a partir de la quema de combustibles fósiles, lo cual ocasiona la liberación de gases de efecto invernadero hacia la atmosfera durante este proceso, generando fuertes impactos al medio ambiente como lo son el cambio climático y el calentamiento global por los cuales se ha incrementado a nivel mundial la demanda tanto de aire acondicionado como de refrigeración; sin embargo, los sistemas de refrigeración convencionales son alimentados por energía eléctrica, además deben operar durante prolongados periodos de tiempo, lo cual termina contribuyendo en mayor medida al calentamiento global. Estas cuestiones han motivado a diversos países a buscar fuentes energéticas alternativas que sustituyan a los combustibles fósiles, siendo la energía solar una de las más aceptadas debido a que es abundante, limpia y presente en todas partes, además de que no produce ruido o algún otro tipo de contaminación; debido a lo anterior y considerando que la demanda de refrigeración incrementa conforme aumenta la intensidad de radiación solar, aunado a las reglamentaciones internacionales enfocadas a la reducción de refrigerantes sintéticos, los sistemas de refrigeración solar son visualizados como una solución lógica a esta problemática.
... Heat is extracted from the low temperature fluid using the heat pump. Solar heating systems are effective especially in buildings with low energy demand for heating [8]. In the development of the new constructions with good insulation and low energy demand the use of heat pump system is a good alternative [9]. ...
The urban, constructed areas are full of buildings and different kinds of pavements and have a noticeable lack of trees and flora. These areas are accumulating the heat from the Sun, people, vehicles, and constructions. One interesting heat collector is the asphalt pavement. How does the heat transfer to different layers under the pavement or does it? What are the temperatures under the pavement in Finland where the winter can be pretty hard? How can those temperatures be measured accurately? These are the main questions this paper gives the preliminary answers to. First the thermal behavior of asphalt and the layers beneath are researched in the laboratory and then the measurement field is bored and dug in the parking in the Western coast of Finland, 63°5′45′′ N. Distributed temperature sensing method was found to be a good choice for temperature measurements. Thermal behavior of pavement has been monitored in different layers and the preliminary results have been published here. The goal of this research is to assess the applicability of asphalt pavements for heat energy collection.
... Furthermore, the ever increasing energy consumption worldwide makes it urgent to find new ways to use the energy resources in a more efficient and rational way. It is estimated that the global energy consumption will increase by 71% between 2003 and 2030 [6]. In addition, currently 80% of the energy on Earth comes from fossil fuel resources [7]. ...
... -17): System schematic for a glazed FPC[Ioan and Marius, 2011] ...
Conventional energy resources are environmentally harmful unlike renewable energy resources. At the end of the last century the world came together to address the problems of climate change; which led to the thinking of ways to conserve energy and reduce the emissions. The geothermal energy is one of the most important ways to conserve energy.
The main objectives of this thesis are: designing of Ground Source Heat pump system for residential applications which is suitable for Iraq environment instead of conventional systems, and using of solar thermal collectors' geothermal hybrid system to get domestic hot water instead of electrical heaters that are used for this process. These objectives have been done theoretically by using MATLAP program and experimentally.
Theoretically, the domestic hot water consumers are classified into three groups depending on number of persons in the family. These groups are (3-5), (6-8), and (9-12) persons, where the daily required hot water and the required area of solar thermal collector is calculated for each group. The underground temperature is calculated theoretically in different places in Baghdad in order to know the possibility of install ground loop heat exchanger (GLHX). Single U-tube and spiral tube GLHX have been designed for space cooling and space heating applications. Also, double U-tube GLHX is designed for space heating applications. Coaxial heat exchanger is designed that is used as a condenser for GSHP in space cooling mode and as an evaporator in space heating mode.
Experimentally, two tons (7 kW) Gibson air conditioner with rotary compressor which consumed 14.2 Ampere nominal current under standard conditions have been modified to fluid-air heat pump (HP) for II
geothermal heat source applications (GSHP) by replacing outdoor air source finned heat exchanger (HEX) with fluid to refrigerant HEX in order to increase coefficient of performance (COP) of the system.
It is observed that the required collector area to cover the hot water for (6-8) consumers family (with 250L hot water) are 8 m2, 5.3 m2, and 4.5 m2 by using Flat Plat (FPC), Evacuated Tube (ETC) and Heat Pipe Evacuated Tube (HPETC) Solar collectors, respectively and these values may be reduced about 30% by using geothermal potential. Baghdad is suitable for installing GLHX due to constant underground temperature (about 24oC) at less than 15m depth. The required borehole depth of single U-tube GLHX for space cooling is 30m when Tout,HP 35 oC, while in the case of both Tout,HP 40 oC and 45 oC the required depth is 45m when fluid mass flow rate of GSHP is 0.1 kg/s. It is seen that the maximum COP for GSHP and ASHP are 4.46 and 2.04, respectively which means that 55% energy saving.
