Analysis of an electricity-cooling cogeneration system for waste heat recovery of gaseous fuel engines

Waste heat recovery (WHR) is one of the most useful ways to improve the efficiency of internal combustion engines, and an electricity-cooling cogeneration system (ECCS) based on Rankin-absorption refrigeration combined cycle for the WHR of gaseous fuel engines is proposed in the paper. This system can avoid wasting the heat in condenser so that the efficiency of the whole WHR system improves, but the condensing temperature of Rankin cycle (RC) must increase in order to use absorption refrigeration system, which leads to the decrease of RC output power. Therefore, the relationship between the profit of absorption refrigeration system and the loss of RC in this combined system is the mainly studied content in the paper. Because the energy quality of cooling and electricity are different, cooling power in absorption refrigeration is converted to corresponding electrical power consumed by electric cooling system, which is defined as equivalent electrical power. With this method, the effects of some important operation parameters on the performance of the ECCS are researched, and the equivalent efficiency, exergy efficiency and primary energy rate are compared in the paper.