Proposal and assessment of a new CCHP system integrating gas turbine and heat-driven cooling/power cogeneration

Abstract

This paper proposes a new combined cooling, heating and power (CCHP) system and presents a comprehensive thermodynamic analysis. This system consists of a gas turbine, a heat-driven cooling and power cogeneration subsystem and a hot-water heat exchanger. Natural gas is burnt in the gas turbine to generate power and the surplus heat contained in the flue gas is recovered and utilized in a cascade way. The high-temperature surplus heat of the gas turbine is firstly recovered by the heat-driven cogeneration subsystem and converted into power through an ammonia-water turbine. Then the exhaust vapor of the ammonia-water turbine drives a single-double LiBr-H2O absorption refrigerator to generate cooling energy. At last the low-temperature surplus heat of the gas turbine is used to generate hot water. Since the efficient utilization of surplus energy, the proposed CCHP system can consume 31.7% less natural gas compared with the stand-alone power, cooling and heating generation systems. Furthermore, part or full power generated by the ammonia-water turbine can also be converted to cooling energy through a compression chiller. In this manner, the proposed CCHP system can adjust the output ratio of cooling and power in a large range from 1.28 to 3.32 to flexibly meet the customers’ variable requirements. The results of economic analyses show that the proposed system has well benefit in practice. This work might provide a new approach to enhance the thermodynamic performance of CCHP systems.