Performance analysis of a solar based novel trigeneration system using cascaded vapor absorption-compression refrigeration system

Solar power tower technique has a strong potential among several solar systems for large-scale power generation. It is crucial to make new, efficient trigeneration unit for solar power tower plant. This work makes a novel supercritical Brayton cycle based combined cycle in which helium is considered as the working fluid for power generation. The cascaded vapor absorption-compression refrigeration system is integrated with traditional Brayton cycle for recovering waste heat to produce additional heating and low temperature cooling effects for food storage. The energy, exergy efficiency and power output of the proposed plant were found as 28.82%, 39.53% and 14,865 kW respectively. The COPcooling and COPheating values were observed as 0.5391 and 1.539 respectively at 850 W/m(2) of direct normal irradiation, 80 degrees C of generator temperature (T-c) and -20 degrees C of evaporator temperature (T-e). Solar sub system is responsible for high exergy destruction around 78.18% (22,763 kW) of total destruction of the overall plant. Moreover, parametric study reveals that performance of trigeneration system is highly affected by the heliostat and receiver efficiency, T-c, T-e and inlet temperature of helium turbine. Also, a comparison with related earlier research has demonstrated that the performance of the current system is superior to that of systems based on the Rankine cycle and supercritical CO2 cycles.

Automated summary

This study proposes a novel supercritical Brayton cycle combined cycle for power generation in solar power tower plants, using helium as the working fluid. By integrating a cascaded vapor absorption-compression refrigeration system with the traditional Brayton cycle, waste heat is recovered to produce additional heating and low temperature cooling effects. The proposed plant has high energy and exergy efficiency, and outperforms systems based on Rankine cycles and supercritical CO2 cycles.