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![Figure 1: Schematic of a solar chimney power plant Al-Kayiem et al. [1] .](profile/Hussain-Al-Kayiem/publication/267471542/figure/fig3/AS:667641366724612@1536189514157/Schematic-of-a-solar-chimney-power-plant-Al-Kayiem-et-al-1_Q320.jpg)
The heat losses within exhaust gases are an unavoidable part of operating any
fuel-fired system. The flue gases still hold considerable thermal energy, which is
exhausted to the atmosphere as waste heat and contributes to global warming.
This paper presents a developed technique to enhance the performance of low
temperature solar thermal systems by...
Contexts in source publication
Context 1
... solar chimney power plant is one of the proven techniques to convert the solar radiation to electrical power. It has three core components -solar collector (made of absorbing medium covered by transparent cover), chimney and wind turbine, as schematized in Figure 1. As the sun heats up the air beneath the solar collector, a pressure gradient is induced causing a continuous flow of air as warmer air escapes the chimney and cooler air is drawn from the surrounding. ...
Context 2
... simulate the process of the fluid and heat flow, a model is constructed by GAMBIT software having air and flue flow panels and inlets and outlets, as shown in Figure 1. The case is simulated as steady, which is quite acceptable since the supplied flue from the thermal source is unchangeable, and 2-D, since the width to the height ration of the cross section in both the air and the flue channels as 1.0 m/0.05 m is quite high. ...
Similar publications
Solar photovoltaic (PV) and solar thermal systems are most widely used renewable energy technologies. Theoretical study indicates that the energy conversion efficiency of solar photovoltaic gets reduced about 0.3% when its temperature increases by 1°C. In this regard, solar PV and thermal (PVT) hybrid systems could be a solution to draw extra heat...
Citations
... Therefore, to overcome the economic limitations, some innovations have been proposed. According to theoretical investigations, a combination of the solar chimney with added heating channels has been presented, in -Kayiem et al., 2012). Other proposals were based on the metallic plates' exploitation inside the collector chamber to intensify the absorption of solar radiation (Al-Kayiem et al., 2012). ...
... According to theoretical investigations, a combination of the solar chimney with added heating channels has been presented, in -Kayiem et al., 2012). Other proposals were based on the metallic plates' exploitation inside the collector chamber to intensify the absorption of solar radiation (Al-Kayiem et al., 2012). A solar chimney-coal-fired power generation combination system was proposed, in which the condenser released low-grade heat to preheat the air inlet to the solar chimney collector (Li et al., 2017). ...
... A significant percentage in world markets reports of the increase in converting wasted gas into energy, and it is expected that the procedure will continue at a constant growth rate [24]. However, it is also being suggested a hybrid solar chimney (HSC) model to enhance the performance of power plant by using a metal sheet as an absorber plate under the collector instead of soil [25,26]. The absorber plate is designed and made as a heat exchanger which heats the extract from hot flue gas and flows in lower part of the collector; while SAC is placed in front/upper part of the absorber plate. ...
In this study, a three-dimensional hybrid solar chimney with an integrated external thermal source is developed to complements the solar energy for uninterruptible power generation using flue gas channels as a supply source in the collector. The hybrid system is examined numerically using ANSYS Fluent software including a solar air collector with a diameter of 6 meters, a 6.65-meter-long chimney, and four thermal channels. The timetable is set for different hours, namely for two modes, i.e. without flue gas during daytime (1st Case), with flue gas during daytime (Case 2-A), and with flue gas during night (Case 2-B). Moreover, the turbine effect in different day hours and with different heat sources during night are applied. The numerical method is validated by comparing its results with previous works based on different chimney heights. The present results show that the hybrid approach increases system performance significantly. Simulation is done in thermal channel with 0.0015 kg/s in chimney temperature of 116 C. The results indicate that mass flow rate and power increased by 7.63% and 11.48%, respectively, compared to the mode with no flue gas. This study proved that the proposed method can eliminate the night defect and allow the operation of solar chimney power plants at night.
... Therefore, continuously the studies on various design of SAC is consider necessary to investigate the flow visualization within SAC and it is effect on efficiency [16][17][18][19][20][21] . Hence, a new model of SAC consisted from double transparent skin surface (DTSS) to upgrade the SAC efficiency has been devised and proposed in this work [22][23][24][25][26] . In details, different DTSS geometrical at variable operating parameters has been simulated by using ANSYS FLUIENT computational fluid dynamics (CFD) to evaluate the optimum design of the SAC part for the SUTPP future work development. ...
This paper presents and discusses a novel Computational Fluid Dynamics simulation of a solar air heater as part of the updraft air tower model for an electrical power generation. A solar air heater is built upon double transparent upper skin to capture the solar energy and create the greenhouse effect, which is forming hot air flow into power generator part. The influence of different transparent skin geometrical of the proposed solar air heater on the tower power plant performance at various operational parameters have been simulated and evaluated using ANSYS Fluent software to solved the Navier-Stockes and energy equations integrated with discrete ordinates (DO) radiation model. The evaluation result demonstrates that as the number of skin solar air heater in collector increases, also the area of these air heaters, the system performance enhances.
... The performance index is given by [21]: ...
Solar chimney is one of the best ways to produce artificial wind to drive wind turbines. But the main problem associated with is that it’s dependence on solar energy and hence can’t be used during night times. The objective of the present work is to modify the existing model; so that it can be used for the generation of power even in nocturnal and cloudy conditions. There are many ways to recover waste heat from different industries, but solar chimney can give one of the leading possible ways to recover it. Waste heat can be used to heat the base or absorber of the solar chimney’s collector; or it can be used to heat the air flowing inside the chimney. Ansys 2019 R1 has been used for the Computational Fluid Dynamics (CFD) validation and analysis of the solar chimney with heat recovery heat exchanger. A heat exchanger (HE) plate of aluminium alloy has been used with syltherm-800 as heat transfer fluid (HTF), and exchanging heat with the air inside the chimney near its base. Effect of different parameters like HTF inlet temperature, mass flow rate of HTF, ambient temperature of air, and diameter of heat exchanger plate on the performance of solar collector of chimney has been analysed. Also, the maximum conversion efficiency of about 5% is achieved, which is more in comparison to solar chimney operating at normal day conditions. Limitation of the present work is related to the storage of heat during day time or there should be continuous supply of waste heat during chimney operations. In this paper, authors have proposed a CFD method for the modification and improvement of solar chimney in Manzanares (Spain) with a waste heat recovery heat exchanger for nocturnal use.
... A significant percentage of increase occurred in the global market of waste transformed to energy, and this trend is expected to continue with steady growth [24]. Nevertheless, [25] and [26] proposed and investigated a hybrid solar chimney (HSC) model to enhance plant performance by utilizing a metal sheet as the absorber plate underneath the collector instead of the soil. The absorber plate was designed and fabricated as a heat exchanger which extracts heat from the hot flue gas that flows through the bottom part of the collector while a SAC is situated at the top/front of the absorber plate. ...
Solar chimneys have the drawback of being unproductive at night. This study proposed a hybrid solar chimney integrated with an external heat source to complement solar energy for uninterrupted power generation. Flue-gas channels were utilized to supply air into the collector passage. The hybrid arrangement was investigated experimentally and numerically. An experimental model comprising a 6 m-diameter solar air collector, 6.65 m-height chimney, and four flue thermal channels was designed and fabricated. The hybrid system was further simulated using ANSYS-Fluent. The numerical procedure was validated by comparing with experimental measurements for a conventional solar chimney with mean differences of 8.7% and 7.8% in air flow velocity and air temperature rise, respectively. Results showed that the hybrid approach considerably enhanced the plant performance. The insertion of flue channels, even with no flue-gas flow, enhanced the velocity and temperature by 6.87% and 6.3%, respectively measured at the chimney base. Simulation results with 0.0015 kg/s at 116 °C flue gas in the thermal channels demonstrated that the air-mass flow rate and collector efficiency enhanced by 12.0%, and 64.0%, respectively. This study proved that the proposed technique can resolve the setback of night operation of solar chimney power plants and enable 24/7 power production.
... In recent years, this system has been developed with the idea of coupling with the waste heat sources from industries to increase the temperature of the working air and thus improving the power output. For instance, Al-Kayiem et al. [1,2] and Chikere et al. [3] channeled hot flue gas into some tubes in or underneath the solar collector so that the working air was simultaneously heated by the solar insolation and the flue gas. Zandian et al. [4] and Zou et al. [5] put heat exchangers containing the hot recycling water from a thermal power plant at the solar collector entrance. ...
... For the working air, as only the gauge pressure is computed in ANSYS FLUENT, the static pressure in Eqn. (1) was set to the sum of the gauge pressure and the ambient static pressure, p ∞ . It should be noticed that, the flue gas was treated as the air in order to avoid the additional complexity of simulating multiple species. ...
A Solar-Waste-Heat Chimney Power Plant (SWHCPP) is similar to a solar chimney power plant (SCPP) but uses both the solar insolation and the waste heat from industries to heat the working air. To model the variation of the air density due to the high temperature rise, a 3D numerical model, in which the air density is modelled by the ideal gas law, is established for the SWHCPP in this study. Comparing with the conventional CFD model and the experimental benchmarks, the new model can suppress the overestimation in the simulated results and generally indicates an acceptable accuracy in the performance determination of the SWHCPP. In addition, a method of directly integrating the air density profiles captures the right variation in the system performance during the numerical experiment with multiple flue gas injection flow rates and it would be more suitable to be used for the modelling research about the SWHCPP. The simulations indicated that more than 50% higher power output was achieved due to multiple-stage heating with the waste heat while the existence of the waste heat slightly influenced the absorption of solar insolation.
... Chikere et al. [4] reviewed the enhancement of the SCPP and suggested a modified SCPP integrated with flue gas as a supplementary source of heat. Al-Kayiem et al. [5] and Al-Kayiem [6] presented the experimental and numerical results of a modified SCPP integrated with an external auxiliary thermal source. They concluded that considerable enhancement was achieved in the performance of the integrated system, and the SCPP was able to produce electricity during daytime and night time because of the continuous heat supply to the absorber. ...
One of the major challenges to the widespread application of the solar chimney power plant is its low-power conversion efficiency because of the three technological processes involved. The chimney efficiency is difficult to improve, and thus enhancing the collector or turbine performance can considerably improve the total plant efficiency. This work focused on enhancing the energy conversion efficiency of the collector and also extending the operation time using a heat storage medium. The solar to thermal conversion and thermal storage capabilities of six ground materials that are potentially available in Malaysia were studied experimentally and numerically. The experimental model was designed such that the six materials were exposed to the same operation boundary conditions. The numerical studies were conducted using ANSYS software, where the geometrical models were developed and simulated using FLUENT for the fluid flow and energy/thermal field studies. The selected ground materials were ceramic, black stones, sawdust, dark-green painted wood, sand, and pebbles. The simulation and experimental results are in good agreement in terms of air stream velocity and energy conversion efficiency. The results showed that the different materials have different heat storage capacities, and that ceramics extend the operation with improved efficiency until nighttime. The results also showed that ceramic and black stones have better performance than the other materials. However, black stones are recommended as the absorbing material for solar chimney power plants in Malaysia and regional countries because they are readily available.
... Chikere et al. [4] reviewed the enhancement of the SCPP and suggested a modified SCPP integrated with flue gas as a supplementary source of heat. Al-Kayiem et al. [5] and Al-Kayiem [6] presented the experimental and numerical results of a modified SCPP integrated with an external auxiliary thermal source. They concluded that considerable enhancement was achieved in the performance of the integrated system, and the SCPP was able to produce electricity during daytime and night time because of the continuous heat supply to the absorber. ...
One of the major challenges to the widespread application of the solar chimney power plant is its low-power conversion efficiency because of the three technological processes involved. The chimney efficiency is difficult to improve, and thus enhancing the collector or turbine performance can considerably improve the total plant efficiency. This work focused on enhancing the energy conversion efficiency of the collector and also extending the operation time using a heat storage medium. The solar to thermal conversion and thermal storage capabilities of six ground materials that are potentially available in Malaysia were studied experimentally and numerically. The experimental model was designed such that the six materials were exposed to the same operation boundary conditions. The numerical studies were conducted using ANSYS software, where the geometrical models were developed and simulated using FLUENT for the fluid flow and energy/thermal field studies. The selected ground materials were ceramic, black stones, sawdust, dark-green painted wood, sand, and pebbles. The simulation and experimental results are in good agreement in terms of air stream velocity and energy conversion efficiency. The results showed that the different materials have different heat storage capacities, and that ceramics extend the operation with improved efficiency until nighttime. The results also showed that ceramic and black stones have better performance than the other materials. However, black stones are recommended as the absorbing material for solar chimney power plants in Malaysia and regional countries because they are readily available.
... The absorber plate stands as a heat exchanger serving the purpose of extracting heat from hot flue gas that flows underneath the bottom part of the collector and in the top/front part of the absorber plate, which was housed by a transparent cover, it absorbs the solar energy to generate air in motion that rotates the turbine at the chimney base to generate electricity. The first laboratory model was designed and investigated experimentally by Al-Kayiem et al. [109] and simulated numerically by Al-Kayiem et al. [191], as in Fig. 30. The system had one absorber plate inclined at 45°and the flue gas was supplied by experimental Gas Turbine unit, as shown in Fig. 30a. ...
... Modified inclined solar chimney integrated with flue gas source. (a) Experimental setup, (b) velocity vector as predicted by CFD simulation.[109,191]. ...
... Elementary experimental measurements on an inclined solar chimney model integrated with flue gas were reported by Al-Kayiem et al. [26]. Then, the same system was simulated and the simulation results were validated through comparison with the measurement results as reported by Al-Kayiem et al. [27]. The experimental and simulation boundary conditions are shown in Fig. 6. ...
Solar is one of the pillars for clean and environment friendly energy. The drawback of the solar is the interruption during the night and cloudy and rainy weather. This paper presents the author’s experience on enhancing the solar thermal systems by integration techniques with either other energy resources or thermal energy storages (TES). The present works includes the hybrid solar drying through integration with thermal backup unit. The experimental results on hybrid drying showed enhancement of 64.1% for Empty Fruit Bunch, and 61.1% for chili pepper, compared with open solar mode drying. Secondly, solar water heating was proved to be sufficient to supply hot water during the day and night time by integration with TES. The experimented system was able to maintain the water hot up to the next morning. On large scale and industrial application, experimental results on modified inclined solar chimney had shown enhancement via integration with wasted flue gas. By this technique, the system was developed to operate 24 hours a day. The efficiency was enhanced by 100% in case of hybrid operation compared with solar mode operation. The research results are demonstrating that the integration techniques can contribute effectively in enhancing the performance of the thermal solar systems.
