Thermodynamic analysis of a CCHP system integrated a chemical recuperation process of methanol decomposition

Abstract

A novel combined cooling, heating and power (CCHP) system is proposed in this work, which mainly consists of an internal combustion engine (ICE) power block, a chemical recuperation block, an absorption refrigeration block and a hot water supply block. The high temperature exhaust gas from the ICE (500 kWe) is firstly used for driving the methanol decomposition to produce syngas of CO and H2 via the chemical recuperation, the produced syngas is input into the ICE for power generation. The exit exhaust gas flows into the water/lithium bromide absorption refrigerator, finally the rest sensible heat of the gas is used for generating the hot water for domestic use or district heating. The system thermodynamic performance evaluation is implemented. The results indicate that the power, cooling and heat of the system under the design condition are 500 kW, 203.4 kW and 255.36 kW, respectively. Correspondingly, the system energy and the exergy efficiencies reach to 78.54% and 45.59%, respectively. Compared with the scheme of directly combusting the methanol for the CCHP, the generated cooling energy is decreased to 203.4 kW from 477.76 kW, while the electric efficiency is improved to 40.98% from 34.21%. Moreover, the required methanol consumption rate is reduced by 16.54%, the exergy losses within the fuel combustion and refrigeration process are decreased evidently. The research findings provide a promising method for improving the performances of the CCHP system.