Potential of applying the thermochemical recuperation in combined cooling, heating and power generation: Route of enhancing the operation flexibility

Abstract

Driving the thermochemical recuperation is an alternative way to enhance the waste heat recovery and stored them as the chemical form, in this work, a new combined cooling, heating and power system is proposed by adopting this effective approach. Before the typical processes of absorption refrigeration and heat exchange for cooling and heating production, the waste heat of exhaust gas released from the prime mover is first recovered through the endothermic thermochemical reaction of methanol decomposition, and then converted into the high quality syngas as the gas fuel. The system thermodynamic model is developed, and two power scenarios of gas turbine and internal combustion engine are considered for evaluation. The results indicate that the released waste heat in the combined cooling, heating and power system achieves favorable recovery and reasonable utilization, regarding to the power generation, the power efficiency is improved by 7.8%-14.83% and realizes a reasonable reduction in fuel consumption. Moreover, the installed thermochemical recuperation sector contributes to evidently broadening the adjustment range of the cooling/heating-to-power output ratio, instead of the fixed profile that strongly depended on the previous turbine/engine operation. In addition, a considerable energy waste can be avoided as far as possible during the system off-design operation with the instantaneously changing energy demand, and then significantly improve the system operation flexibility. The research findings provide a promising way to enhance the waste heat recovery and highlight the application potential of thermochemical recuperation for the combined cooling heating and power production.