Solar Chimney Power Plant System Research Articles

Comparative Analysis of Solar Chimney Power Plant Chimney Design: Performance Evaluation and Material Cost Comparison

Abstract: This paper investigates different configurations of solar chimney design in a solar chimney power plant system. Mathematical analysis of the system has been done in Ansys software. The results of the maximum (inlet) velocity, pressure, efficiency, and temperature of the air are obtained for base type, convergent, divergent, sudden contraction, and sudden expansion types of chimneys. Furthermore, the electrical power output of Solar Chimney Power Plants has been determined for different chimney types. In this analysis, one Solar Chimney Power Plant (SCPP) with a solar collector diameter of 258 m and a chimney height of 197 meters and outlet diameter of 10 m has been taken as the basis. It has been found that sudden expansion and divergent types of chimneys give higher output power than the other types of chimneys. Also, while calculating the cost of materials of the different types of chimneys, it has been found that the sudden expansion type of chimneys is costing less than other types of chimneys. When power output was compared, it was found that the sudden expansion type of chimney gives higher output than other chimneys. Detailed simulation, testing, and analysis are necessary to consolidate the results.

Numerical Simulation of The Influence of Geometric Parameter on The Flow Behavior in a Solar Chimney Power Plant System

Numerical simulations have been carried out on the solar chimney power plant systems. This paper gives the flow field analysis for a solar chimney power generation project located in Baghdad. The continuity, Naver-stockes, energy and radiation transfer equations have been solved and carried out by Fluent software. The governing equations are solved for incompressible, 3-D, steady state, turbulent is approximated by a standard k -  model with Boussiuesq approximation to study and evaluate the performance of solar chimney power plant in Baghdad city of Iraq. The different geometric parameters of project are assumed such as collector diameter and chimney height at different working conditions of solar radiation intensity (300,450,600,750 and 900 W/m2) to gain the optimal designed structure. The results show that the change of collector diameter and chimney height has considerable effects on the performance of the system. The velocity increase when the collector diameter and chimney height increase and reach to the maximize value at H=D 12 m and when solar intensity (900 W/m2). The study shows that Iraqi weather are suitable for this system.

Numerical investigation on the performance of a Solar Chimney Power Plant System (SCPP)

AbstractIn this work, a parametric two‐dimensional computational fluid dynamics (CFD) analysis of solar chimney power plant was performed to describe the physical mechanism in order to establish realistic predictions for the operation of such plants in different location in Algeria. The developed numerical model includes a solar radiation model within the collector; an energy storage model; an air flow and heat transfer model, and a turbine model. It is based on the solution of the Navier‐Stokes equation for turbulent flow using the standard k − ϵ model. The Boussinesq model was adopted in this simulation for the density of the fluid. The boundary conditions were adapted according to the selected sites and the effect of this on the SCPP performance was studied. The numerical simulation was performed using the commercial computational fluid dynamics (CFD) code “Ansys Fluent 19.2”.

Numerical simulation and performance evaluation of filter-equipped solar chimney power plants

A solar-assisted large-scale cleaning system (SALSCS) is a solar thermal system that utilizes the concept of a solar chimney power plant (SCPP) to improve outdoor air quality. In an SALSCS, air purification is facilitated by passing the buoyancy-induced airflow through an air filter installed in the system. In the current study, a new solar chimney system called a filter-equipped SCPP (FSCPP), which is a hybrid of SCPP and SALSCS, is proposed and investigated to identify the possibility of generating electrical power and purifying outdoor air simultaneously. A three-dimensional numerical model is developed to study the heat transfer and fluid flow inside the solar chimney. The simulation method is implemented and validated with experimental data from the literature. The simulation results reveal that the pressure drop is higher across the filter than at the turbine in the FSCPP, indicating a higher energy consumption at the filter. Numerical simulations are also carried out to compare the performance of the SCPP, SALSCS and FSCPP. The results show that the FSCPP has the lowest volume flow rate and the highest temperature rise. The electrical power generated by the FSCPP is only about 20 ∼ 40% of the SCPP’s power generation, but its air purification capabilities approximate those of the SALSCS, with only a 2 to 4 % reduction. The influence of the system’s dimensions on overall system performance is also analyzed. The FSCPP shows an enhancement in primary capabilities (i.e., power generation and air purification) with an increase in the width and height of the solar chimney system of up to 200 meters. • A filter-equipped solar chimney power plant (FSCPP) system is proposed. • Numerical simulations are conducted to evaluate the performance of FSCPPs. • The electrical power generation of FSCPP decreased by 20 to 40% compared to SCPP’s capability. • The air purification capability of FSCPP is almost similar (about 96 to 98%) to that of SALSCS.

Impact study of integrating solar double chimney power plant into electrical grid

Integrating a novel design of Solar Double Chimney Power Plant system (SDCPPS) into a traditional medium voltage (MV)) distribution grid in the Safawi area, Jordan was presented. The impact of full-day integration of the maximum electrical energy on the performance indices of voltage profile (VP), power factor (PF), losses, and voltage step (VS) was assessed. The SDCPP operates under uniform electrical energy production even under varied weather conditions to generate 286.6 MWh/year. Connecting the SDCPP to the Medium Voltage (MV) point allows for electrical energy stabilization, minimizes energy losses, and maintains the allowable PF. The maximum reduction of voltage deviation (VD), and the average and maximum reduction in the losses were 0.93%, 0.34%, and 0.43%, respectively, The VS limit at the point of common coupling was within the 3% of the rated voltage. The PF dropped to 0.72 due to the increase of pure active power generated from the SDCPPS. Improving the combined PF is based on the BSP, which should be operated under 0.88 leading to keeping the SDCPPS running in the PF control mode as per connection code requirements. The performance of the SDCPPS has the edge over other renewable energy sources for all performance indices.

Economic and environmental assessment of the implementation of solar chimney plant for water production in two cities in UAE

• Solar chimney power plant (SCPP) system is used to generate electrical power and produce distilled water for different wind speeds in two cities in UAE. • Sharjah and Alain cities in UAE were selected based on the geographic location and metrological data. • Alain city shows more annual electrical power and water production than Sharjah city. • The economic and environmental considerations were evaluated and compared with the reverse osmosis (RO) technique. In this paper, a solar chimney power plant (SCPP) system is modeled and simulated using MATLAB code. The economic and environmental considerations were analyzed for the SCPP. The implementation of the SCPP system in Sharjah and Al Ain cities in the United Arab Emirates (UAE) were compared in terms of electrical power generation and cumulative water production, as well as the potential of increasing the wind speed by 2.5% - 10% with a step of 2.5%. The selected cities were considered due to the big difference in the relative humidity. The results showed that even though Sharjah’s water production was more stable and consistent, Al-Ain would have significantly higher water production and slightly lower power generation. After increasing the wind speed, both cities showed similar behavior of a significant increase in water production and a slight decrease in power generation. The novel design was analyzed and compared to the reverse osmosis technology from an economic and an environmental perspective. Using the SCPP is in alignment with the 2030 vision of the UAE for both electrical power generation and water production. Furthermore, the SCPP can be an effective solution to solve the demand for energy and water and reduce the effect of greenhouse gas (GHG) emissions.

Structural optimization to reduce the environmental crosswind negative influence on the performance of a solar chimney power plant system

The solar chimney power plant system (SCPPS) is a clean and pollution-free facility for generating electric power. To further improve the heat collection efficiency of SCPPS, reduce the influence of external unsteady environment crosswind, a bank of transparent baffles was proposed to be installed at the entrance of transparent cover in SCPPS. Combined with the discrete ordinates (DO) radiation model and solar load model in Fluent, the latitude and longitude of Hohhot and actual weather parameters were taken as boundary conditions. Numerical simulation of SCPPS model with external air domain and different number of baffles were carried out. The accuracy of numerical simulation was verified by experimental results. There are three different types of models discussed here: the SCPPS with no baffle, the SCPPS with one baffle, the SCPPS with two baffles. Under the condition of different baffle number, the distribution of temperature, velocity, pressure, turbulence and heat collecting efficiency were given to determine the optimal baffle number. The results show that the average temperature of chimney inlet with one baffle and two baffles are 0.92% and 3.92% higher than that with no baffle, respectively; the average velocity of chimney inlet with one baffle and two baffles are 11.83% and 18.70% higher than that with no baffle, respectively; the average collector efficiency of one baffle and two baffles are 28.45% and 58.52% higher than that of without baffle, respectively. Compared with without baffle and one baffle, adding two baffles can more effectively reduce the heat loss of SCPPS in Hohhot under different environmental crosswind speeds, and alleviate the negative effects of environmental crosswind.

Effect of chimney shadow on the performance of wind supercharged solar chimney power plants: A numerical case study for the Spanish prototype

Three-dimensional numerical simulations for a solar chimney power plant (SCPP) and wind supercharged solar chimney power plant (WSSCPP) based on the Spanish prototype using the solar ray-tracing algorithm were performed to study the shadow effect of the chimney. The area of the shadow region increases with an increase in the incident angle of the solar rays. A parametric study was performed by varying the incident angle from 0° to 30°. The temperature and velocity distributions at different incident angles were analyzed. In addition, we investigated the chimney shadow effect in several comprehensive SCPP systems. The findings show that the turbine shaft powers of the SCPP and WSSCPP were reduced by 22.4% and 13.7%, respectively, when the incident angle increased from 0° to 30°. In conclusion, it is important to consider the chimney shadow effect when estimating the performance in the design and cost analysis of SCPP systems.

Simulation and Experimental Study of the Influence of the Baffles on Solar Chimney Power Plant System

The solar chimney power plant system (abbreviated as SCPPS) is a clean and pollution-free facility for generating electric power. To improve the generating efficiency, a bank of baffles can be arranged under the collector in SCPPS. ANSYS Fluent 18.2 was used to numerically simulate 3D models of SCPPS with or without baffles, and an experimental apparatus was built for verification. There are seven different types of model discussed here: the SCPPS without baffles (prototype), and other six types of models with different baffles (a-type, b-type, c-type, d-type, e-type, and f-type). The pressure fields, temperature fields, velocity fields, and power outputs of different models under the different baffles are discussed. It is shown that the addition of baffles in the system can increase the temperature field, pressure field, velocity field, and power output to varying degrees, but b-type baffles better improve the temperature and velocity uniformity of the system, and intensify the output power. For b-type, the simulation of the systems with five different baffle numbers (3, 4, 6, 8, and 12, respectively) was carried out, and it was concluded that the system with 12 baffles is the best in improving the system performance. It can be seen that the more the number of baffles, the better the performance of SCPPS. The experiments are also verified the simulation.

Performance analysis of a solar chimney power plant system in two Algeria regions

In this paper, we have investigated the possibility of implementation of three solar chimney systems in the two Algeria regions (Constantine, Tamanrasset). Numerical simulations were performed for the prototype geometry in Manzanares, Spain. Usage of CFD techniques (Computational Fluid Dynamics); we have simulated a two-dimensional axisymmetric model of an SCPP with the RNG k–ε turbulence. Using a band radiation model to solve the equation of radiation transfer by implementing the model of discrete ordinate radiation. Our results show that the secondary and tertiary collector roof system is able to achieve the highest electricity generation. The obtained results show the solar chimney power plant systems can be produced from 51 to 79 kW of electricity over the year and the highest hourly electricity produced in June is around 47 to –80 kW. The highest electricity generation has been recorded in the Tamanrasset region.

Developing and Implementation of an Optimization Technique for Solar Chimney Power Plant With Machine Learning

Abstract Green energy has seen a huge surge of interest recently due to various environmental and financial reasons. To extract the most out of a renewable system and to go greener, new approaches are evolving. In this paper, the capability of Artificial Neural Network and Adaptive Neuro-Fuzzy Inference System in geometrical optimization of a solar chimney power plant (SCPP) to enhance generated power is investigated to reduce the time cost and errors when optimization is performed with numerical or experimental methods. It is seen that both properly constructed artificial neural networks (ANN) and adaptive-network-based fuzzy inference system (ANFIS) optimized geometries give higher performance than the numerical results. Also, to validate the accuracy of the ANN and ANFIS predictions, the obtained results are compared with the numerical results. Both soft computing methods over predict the power output values with MRE values of 12.36% and 7.25% for ANN and ANFIS, respectively. It is seen that by utilizing ANN and ANFIS algorithms, more power can be extracted from the SCPP system compared to conventional computational fluid dynamics (CFD) optimized geometry with trying a lot more geometries in a notably less time when it is compared with the numerical technique. It is worth mentioning that the optimization method that is developed can be implemented to all engineering problems that need geometric optimization to maximize or minimize the objective function.

Numerical and experimental investigation of solar chimney power plant system performance

ABSTRACT A prototype of a solar chimney power plant was performed by modeling in this study. The performed prototype was experimentally confirmed. Temperature, velocity, and radiation values were measured to actualize the confirmation. Experimental data that were obtained to determine the performance of solar chimney whose prototype was actualized by the help of measured values were computationally analyzed. The geometry of a solar chimney in the analysis was bidimensionally (2D) drawn on an axis of symmetry. The numerical simulation was analyzed with computational fluid dynamics (CFD) method. Since analysis results show that there is turbulent flow in system (RNG), k-ɛ turbulence model was used. Continuity, momentum, and energy equations were applied to the solar chimney system via the finite volume method. Moreover, DO (discrete ordinates) model was inserted in analysis to evaluate the radiation effect in the collector area. In addition to all these, correlation results between SPSS 17 statistics program and data obtained were evaluated. Finally, with reference to the comparison between numerical and experimental results, data obtained and numerical data are close to each other; the prototype is applicable to the real systems.

Effect of the chimney design on the thermal characteristics in solar chimney power plant

Solar chimney power plant (SCPP) is an interesting project to produce clean and sustainable energy. An efficient SCPP system requires a very high chimney, and thus the optimization of the chimney shape presents an important way to enhance the SCPP performance. The aim of this paper is to analyze the effect of the divergent chimney shape on the airflow behavior inside SCPP. A comparison between four chimney shapes is carried out using CFD method: two cylindrical chimneys with different diameters and two divergent chimneys with different shapes. Indeed, both parameters were studied: the ratio of the inlet and outlet diameter of the chimney and the shape of the chimney which both hyperboloid and conical. The SCPP prototype was tested numerically and experimentally to validate the present computational outcomes. The obtained results confirm that the divergence shape affects directly the efficiency of the SCPP system. Moreover, the hyperboloid chimney presents the efficient solution which produces an important power output with keeping the chimney height constant.

Study on the performance of a solar collector with heat collection and storage

The collector in a solar chimney power plant system (SCPPS) is a heat exchanger that converts solar energy into the internal energy of the transport medium. This study proposed a new collector structure that could be used in combination with agricultural production, based on modelling and experimental research. Comparison of the heat collection performance of the new collector structure with the performances of two traditional collector structures, indicated that the new structure, in which the heat absorber plate was located in the middle of the collector, had the best performance. Since the airflow channel was divided into upper and lower channels, the heat transfer area was increased, and the heat transfer in the channel was enhanced. In addition, the perforated heat absorber plate with a certain porosity characteristic had a better heat transfer performance than the full heat absorber plate and could improve the stability and continuous power generation capability of SCPPS.

Research on Micro Wind Turbines in Solar Chimney Power Plants with Vertical Collectors

On the basis of the design theory of wind turbines, a micro wind turbine was designed for a solar chimney power plant (SCPP) with vertical collectors. The performance of the turbine was analyzed by the combination of theoretical analysis, numerical simulation, and experiment. Findings show that the turbine power increases with the wind speed. Airfoil and installation and torsion angles significantly influence the turbine power. Results of the numerical simulation and experiment show that the optimal airfoil, installation angle, and torsion angle are NACA 4412, 40°, and 20°, respectively, and that the same growth trend is observed along with the wind. Therefore, the simulation was proven to be accurate by the experiment, which indicates that the designed turbine can satisfy the design requirements and can be used in SCPP systems with vertical collectors.

Numerical simulation of solar chimney power plant adopting the fan model

Abstract Numerical simulations and design of solar chimney power plant adopting the fan model was presented in this study. A mathematical model describing fluid flow and heat transfer has been set up for the three regions of solar chimney power plant: collector, chimney and turbine. The Spanish prototype was chosen as an example for numerical simulation that incorporates turbine model, simulation during turbine operation and no load conditions were compared. For this purpose a simulation of 3D solar chimney power plant system with the standard k-e turbulence model was developed, using CFD Ansys Fluent. Furthermore the effect of turbine operation and the influences of pressure drop across the turbine and solar radiation were investigated and the results revealed that the variation of solar radiation has an evident effect on the flow and heat transfer characteristics. Meanwhile the influence of turbine pressure drop on the collector efficiency was slight, while has a considerable effect on the power output.

Efficiency enhancement of solar chimney power plant by use of waste heat from nuclear power plant

Abstract A solar chimney power plant (SCPP) offers an efficient method of converting solar irradiation to electrical power. It can be combined with a nuclear power plant to improve its efficiency and minimize its environmental impact. Rather than dumping the waste heat rejected by a nuclear power plant to a wet cooling tower, a better solution may be to connect it to an SCPP. This is particularly true in arid regions. The SCPP can serve the function of a dry cooling tower and produce additional electrical power. In a solar chimney power plant, the energy of buoyant hot air is converted to electrical energy. SCPP includes a collector at ground level covered with a transparent roof. The sun heats the air inside the collector and the ground underneath. A tall chimney is placed at the center of the collector, with a turbine located at the base of the chimney. In this investigation, the surplus heat from the nuclear cycle is used to increase the temperature of the air in the collector and therefore produce more electricity in the solar chimney power plant. The efficiency of the nuclear plant will be lowered due to the higher temperature of the condenser, but the loss can be made up by the increased power of the solar chimney. Heat from the sun is always free once the solar plant has been constructed and is not normally considered in the efficiency calculation. Computational fluid dynamics (CFD) and thermal analysis have been performed to apply the available surplus heat from the nuclear cycle and to measure the available kinetic energy of air for the turbine of the solar chimney power plant system. The feasibility of the system is evaluated, and the thermal efficiency of the combined power plant has been computed. By applying this idea to a typical 1000 MW nuclear power plant with a nominal 35.3% thermal efficiency, its efficiency can be increased to 42.0%. The combined cycle as presented is advantageous in environments where water is scarce. The cooling tower is replaced by the solar chimney power plant utilizing the surplus heat from the available warm steam in the secondary loop of the reactor.

View Factor of Solar Chimneys by Monte Carlo Method

A typical solar chimney power plant (SCPP) system mainly contains three components, namely, solar collector, tower and turbine. The collector heats up ambient air entering to the system by buoyancy force. Updraft airflow is then generated in the chimney and drives the pressure-staged turbine in the chimney base to generate electricity or ventilation of buildings. A part of the solar radiation is absorbed by solar collector directly, which is greater than which reflected by collector to the tower. But this amount of reflection can enhance the efficiency of the system. Determining more precise view factor between collector and the tower is essential for solving heat transfer equation. In this study, results obtained by Monte Carlo method are compared with analytical method which is available in literature for calculating the view factor. With increasing the ratio of the length to the radius of the tower, configuration factor increases slightly. Also, at higher radius of the collector, supposing length and outer radius of the chimney are unchanged, the view factor decreases. This behaviour can also be seen by analytical solution, but the result of analytical solution is much lower than that one obtained by Monte Carlo solution. It is suggested to designers and researchers to use the results obtained by Monte Carlo method, which seems to be more accurate.

Numerical simulation of a solar chimney power plant in the southern region of Iran

Three-dimensional numerical simulations are performed to investigate the effects of pressure drop across the turbine and solar radiance on the performance of a solar chimney power plant (SCPP). The SCPP system expected to provide electric power to a city is located in southern region of Iran (city of Lamerd, Fars province). Its dimensions are similar to the Manzanares prototype (built in Spain, 1970s). The results demonstrated that the SCPP can provide up to 40–200 KW of power, depending on the season. It was found that the turbine pressure drop and the solar radiation had significant effects on the first and second law efficiencies.

Experimental and numerical analysis of the collector roof height effect on the solar chimney performance

The aim of this work is to study and optimize the characteristics of a solar chimney power plant (SCPP) using numerical and experimental way. The numerical simulation is performed using the commercial computational fluid dynamics (CFD) code “Ansys Fluent 17.0”. An experimental setup of a SCPP is developed in the national school of engineers of Sfax, University of Sfax, Tunisia in the North Africa. The comparison between the numerical and the experimental results have shown a good agreement. The effect of the collector roof height on the solar chimney performance is performed. The local characteristics of the air flow inside the SCPP system are presented and analyzed such as; the temperature, the velocity, the pressure and the turbulence characteristics. Results confirm that the collector roof height is very influential on the optimization of the SCPP. In fact, an increase in the generated power is recorded while decreasing the collector roof height.