An experimental study on the thermal performance of a solar chimney with different dimensional parameters

Numerical investigation of solar chimney power plants performance for Saudi Arabia weather conditions

It is important to analyze the variables influencing the performance of the solar chimney power plant (SCPP) according to output power as well as efficiency. The most important of these variables is the geometric dimensions, solar radiation intensity, and ambient temperature. In this experimental and numerical study, a prototype with variable dimensions was manufactured. A theoretical study was presented by creating a numerical model that helps in analyzing the governing equations, such as the continuity, momentum, and energy equations, in addition to the turbulence model equations (k–ε). The calculations show the influence of chimney height, diameter, solar collector diameter, inlet collector gap, temperature, and solar radiation on the SCPP performance. These variables were also tested experimentally, and the effect of each variable on the efficiency and output power was demonstrated. The maximum velocity was at the turbine exit, about 18.5 m/s in the case of the Spanish model, while it was 2.2 m/s for the present prototype. The maximum temperature value was 333 K for the Spanish model at a collector radius ratio of 3. The maximum output power was 156 mW for the Spanish model. For the current prototype, the maximum airflow temperature was 67 °C when the chimney height was 3 m; by decreasing the chimney height to 2.5 and 2 m, the maximum temperature decreased to 63 and 54 °C, respectively, which are about 6.5% and 19% deterioration. The results show that the relationship between the output power and any of the geometric dimensions is direct. The overall efficiency relationship is direct with the height and diameter of the chimney and inverse with the diameter of the collector and the height of the collector entrance. The output power rises with increasing solar radiation and slightly drops with increasing ambient temperature. The reliability of the numerical solution was verified by comparing the numerical and experimental results, as well as the data of the Spanish model. The agreement was satisfactory, with the mean percentage error (MPE) not exceeding 1.5% for all performance parameters.

A simple thermal model is developed for solar chimney thermal power system and validated by the comparison between the simulated results and those simulated by Schlaich et al. Based on a proposed 200 MW power plant in a desert in western China a special climate, which is formed around the giant solar chimney power plant by the volume of warm air flowing from the chimney outlet to a high altitude, is simulated and analyzed. An atmospheric circulation and rainfall are formed. It is found that the solar chimney power plant increases the chance of rainfall, especially for low-humidity air in the desert region, supporting the agriculture in the local area and promoting a part of the desert region to be reformed to fertile soil. Further, the effects of many factors on the rainfall area around a commercial solar chimney thermal power plant are also analyzed. It is concluded that by keeping other conditions equal, solar radiation of more than 706 W∕ m2 , a collector area of more than 10.45 km2 , a chimney height ...

Development of analytical model for solar chimney power plant with and without water storage system

A solar chimney power plant system is theoretically designed for future erection in Jordan. Analytical analysis of the system is simulated by mathematical software. The actual values of solar irradiation in Jordan are used in the simulation to predict the power output of the solar chimney power plant. The output results of the maximum (inlet) values of velocity, pressure, and mass flow rate of air versus the chimney height variation are obtained. Furthermore, the electrical power output and the efficiency of chimney versus chimney height variation were determined. For a solar collector diameter of 40 m and a chimney diameter of 3.5 m, the maximum power output (85 kW) was obtained for a chimney height of 210 m.

Economic analysis of a 1 MW solar chimney power plant in Tozeur, Tunisia

This work is part of a joint project funded by the Science and Technology Development Fund (STDF) of the Arab republic of Egypt and the Federal Ministry of Education and Research (BMBF) of the Federal Republic of Germany. Continuation of the use of fossil fuels in electricity production systems causes many problems such as: global warming, other environmental concerns, the depletion of fossil fuels reserves and continuing rise in the price of fuels. One of the most promising paths to solve the energy crisis is utilizing the renewable energy resources. In Egypt, high insolation and more than 90 percent available desert lands are two main factors that encourage the full development of solar power plants for thermal and electrical energy production. With an average temperature of about 40 °C for more than half of the year and average annual sunshine of about 3200 hours, which is close to the theoretical maximum annual sunshine hours, Aswan is one of the hottest and sunniest cities in the world. This climatic condition makes the city an ideal place for implementing solar energy harvesting projects from solar updraft tower. Therefore, a Solar Chimney Power Plant (SCPP) is being installed at Aswan City. The chimney height is 20.0 m, its diameter is 1.0m and the collector is a four-sided pyramid, which has a side length of 28.5 m. A mathematical model is used to predict its performance. The model shows that the plant can produce a maximum theoretical power of 2 kW. Moreover, a CFD code is used to analyse the temperature and velocity distribution inside the collector, turbine and chimney at different operating conditions. Static calculations, including dead weight and wind forces on the solar updraft chimney and its solar collector, have been performed for the prototype. Mechanical loading and ambient impact on highly used industrial structures such as chimneys and masts cause lifetime-related deteriorations. Structural degradations occur not only from rare extreme loading events, but often as a result of the ensemble of load effects during the life-time of the structure. A Structural Health Monitoring (SHM), framework for continuous monitoring, is implemented on the solar tower. For the ongoing case study, the types of impacts, the development of the strategic sensor positioning concept, examples of the initially obtained results and further prospects are discussed. Additional wind tunnel tests have been performed to investigate the flow situation underneath the solar collector and inside the transition section. The flow situation in and around the SCPP has been simulated by a combination of the wind tunnel flow and a second flow inside the solar tower. Different wind tunnel velocities and volume flow rates have been measured respectively. Particle Image Velocimetry (PIV) measurements give some indication of the flow situation on the in- and outside of the solar tower and underneath the collector roof. Numerical simulations have been performed with the ANSYS Fluent to validate the experimental tests.

Study on the Performance of a solar chimney power plant chlef, Algeria region was presented in this work. The solar chimney is used in hot areas such as Chlef with high intensity of solar radiation. In this work, the solar chimney power plant (collector, chimney and turbine) is modeled theoretically, and the global solar radiation, the air temperature was measured during the period of 01/01/2015 to 1/06/2016. The model is employed in simulation to predict the electrical power produced by the solar chimney plant using the meteorological data of Chlef region. The effect of the geometrical parameters on the performances of the solar chimney power plant was studied. The influence of chimney height on electrical power produced is simulated in order to have the optimum SCPP to respond to the electricity demand in Chlef region. The performance characteristics of solar chimneys indicate that the dimensions of the chimney (height of the chimney, diameter of the collector, height of the collector and the diameter of the chimney) and the climatic condition (air temperature and solar radiation) are important parameters in the production of electrical energy.

The present work involves a new and novel upgrading design to the classical solar chimney power plant (SCPP) structure. The SCPP design was modified by adding a co-centric secondary external chimney to the SCPP structure to enhance energy production. In the new improved design, named the solar double-chimney power plant (SDCPP), the internal chimney, operates like a traditional SCPP to produce electricity during the daytime whereas the secondary external chimney operates as 10 cooling towers (CT) in a series. Each CT is equipped with a turbine and water sprinklers for further energy production. The new design offers the operation of the SCPP during the day and the continuous operation of the CT (day-and-night). A mathematical model that includes the energy and mass balance equations of the system was built using MATLAB. The SDCPP system produced up to 993 MWh of electrical energy, which is 2.6 times higher than the traditional SCPP (377 MWh). The new design configuration achieved a percentage of thermal efficiency (%ηth) of 1.6%, which is 200 times greater than the SCPP. The economic assessment of the new system revealed a 50% reduction in the localized cost of energy (LCOE) compared with traditional SCPP. The key advantage of the new design is related to the use of low-cost material in constructing the secondary chimney to reduce the fixed capital cost and prompt the economic feasibility of the system. Overall, the proposed SDCPP offers a feasible and economic solution to produce electricity and to potentially reduce greenhouse gas emissions.

Exergoeconomic assessment and multi-objective optimization of a solar chimney integrated with waste-to-energy

Integrating solar chimney power plant with electrolysis station for green hydrogen production: A promising technique

Solar chimney power plants generate thermal heat and electrical power using the radiation from sun. These systems are characterized by their high costs. In fact, it is required to optimize the components of the solar system such as the collector, the chimney, the absorber, and the turbine. This paper focuses on the effect of the number of turbine blades on the air flow within a small prototype of a solar chimney power plant. Four configurations with different turbine blades are proposed to study the effect of the turbine blades number on the thermal characteristics of a solar chimney power plant. For each configuration, the distribution of the magnitude velocity, the air temperature, the pressure, the turbulent kinetic energy, and the turbulent viscosity are presented and discussed. This paper is identified to be of interest for engineers and designers for increasing the power output of a solar chimney power plant.

Recent developments and innovations in solar chimney power technologies: A focus on the last two decades

Total global renewable energy capacity has been increasing worldwide, i.e. doubled from 2007 to 2016. The main disadvantage of most renewable energy based plants is the lack of reliability for constant electricity production. Solar chimney is a renewable based plant with a power production of near zero during the night times. In this study, we have proposed a renewable integrated cycle by combining two plants and thereafter produce a reliable amount of electricity all the time. The proposed combination is achieved by injecting outlet air from the condensers of Tehran’s waste to energy plant into the bottom of the chimney tower, just below the turbine. Tehran’s average climate data for 12 months of the year is initially obtained and the Manzanares prototype is used for the solar chimney power plant model. The solar chimney power plant is simulated with 3D CFD simulation. The final power output of the solar chimney power plant reaches 20–70 kW and increased 20%–1200%, compared to the case without injection. This means power output of solar chimney power plant is at least 20 kW in the hottest night of the year with 5% relative humidity. We have concluded that by combining these renewable based plants, one of the most important solar chimney disadvantages could be removed.

Analysis of some available heat transfer coefficients applicable to solar chimney power plant collectors