Presenting a power and cascade cooling cycle driven using solar energy and natural gas

A configuration is presented where solar energy is parallel with fossil fuel to steadily supply a combined power and cascade cooling system. The cascade cooling system produces a steady cooling load at shallow temperatures. The variations of solar radiation during a year are considered. The system combines an improved ammonia-water power cycle with an absorption-compression cascade refrigeration system. The exhaust from the power cycle drives the absorption chiller. Working fluids are ammonia-water for absorption and power cycles and R134a for compression chiller. The effects of turbine inlet temperature, the ammonia concentration in the power cycle, boiler pressure, and generator temperature are investigated. Considering the cooling section's exergy efficiency, the generator temperature is optimized at 110.5 degrees C. The power cycle's boiler pressure and ammonia concentration are optimized using a genetic algorithm for various cooling loads at various turbine inlet temperature values to find the maximum annual exergy efficiency. The results show that, in all investigated cooling loads, the maximum annual exergy efficiency with a mean value of 65.66% happens at the turbine inlet temperature of 210 degrees C, an average boiler pressure of 58.56 bar, and an average ammonia concentration of 81.16%. (c) 2022 Elsevier Ltd. All rights reserved.