Lithium Bromide-Water Absorption Refrigeration System Driven by Automobile Exhaust Gas: Thermodynamic Study

Abstract

This manuscript conducts a thermodynamic investigation into the feasibility of using engine waste heat as exhaust gas to operate a 5 Kw cooling capacity of a lithium bromide-water Absorption Cooling System (ACS). We investigated the Performance Coefficients (COP) of the generator, condenser, absorbent and evaporator at different temperatures, as well as the impact of the heat exchanger effectiveness on the system COP. The results indicate that the system performance was more effective at high evaporator and generator temperatures; at generator temperature 90 °C and evaporator temperature 5 and 15 °C, it was 0.7398 and 0.8228, respectively and low absorber and condenser temperatures. The COP was 0.7617 at the condenser and generator temperatures of 40 and 90 °C, respectively. At the same conditions, the COP was 0.8082 at the condenser temperature of 30 °C. Additionally, the increased effectiveness of the solution heat exchanger leads to an increase in the COP. At the condenser, evaporator, generator, absorber and effectiveness (40, 7, 90, 35 °C and 0.6), the COP was 0.7781. At the same temperature and 0.9 effectiveness heat exchanger, COP was 0.8321, while the circulation ratio remained unchanged.