Thermo-economic analysis of a novel trigeneration cycle enabled by two-phase machines

A novel trigeneration cycle with two-phase fluid devices (compressors and expanders) and a wet working fluid is proposed. The steady-state mathematical model of the cycle is developed and implemented in Matlab environment. The sensitivity analysis is performed by changing simultaneously five process parameters to determine the best operating conditions serving two typical trigenerative consumers with various energy requirements (i.e. tertiary and industrial). The cycle exploits a generic typology of thermal source. The energy performances and the economic profitability of the cycle are compared with the counterparts of the first cycle with two-phase machines that the Authors have investigated in previous publications (TC2M) and with the counterparts of several commercialized CCHP systems. For both consumers, the cycle allows increasing the energy performances compared to TC2M with varying of the two-phase machines isentropic efficiencies. Moreover, the highest energy performances of the cycle are larger or similar to those of the best energy performing marketed CCHP plants for tertiary or industrial consumers, respectively. The cycle shows higher economic profitability than TC2M and several commercialized CCHP plants except for tertiary consumer at the minimum number of annual operating hours.