Energy, exergy, energy-saving, economic and environmental analysis of a micro-gas turbine-PV/T combined cooling, heating and power (CCHP) system under different operation strategies: Transient simulation

A micro-gas turbine (MGT) combined cooling, heating and power system coupled with low concentrating photovoltaic/thermal-heat hump (LCPV/T-HP) and absorption chiller is proposed in this study. LCPV/T is used as the heat source of HP to realize mutual promotion. The performance of CCHP system under different operation strategies is dynamically simulated and analyzed by TRNSYS software from energy, exergy, energy-saving, economy and environment. The results demonstrate that both high temperature water source heat pump (HWHP) and low temperature water source heat pump (LWHP) achieved better COP in following electric load (FEL) mode. The average COP of HWHP and LWHP are 22.69% and 4.75% higher than the rated COP, respectively. Annual total cost per unit building area (ATCUBA) and carbon dioxide emissions per unit building area (CDEUBA) are also more advantageous in FEL mode, while primary energy consumption per unit building area (PECUBA), ATCUBA and CDEUBA seems less preferable in following thermal load (FTL) mode. The exergy efficiency and energy efficiency of the system in FEL mode are 19.96% and 41.90% in summer, and 25.13% and 59.36% in winter. Additionally, the equipment with higher exergy loss is mainly LCPV/T, gas-fired boiler, ab-sorption refrigeration unit, MGT and hot water generator under the three operation strategies.

Automated summary

This study proposes a micro-gas turbine (MGT) combined cooling, heating, and power system with low concentrating photovoltaic/thermal-heat pump (LCPV/T-HP) and an absorption chiller. The performance of the system under different operation strategies is analyzed using TRNSYS software from various perspectives. The results show that high-temperature water source heat pump (HWHP) and low-temperature water source heat pump (LWHP) achieve better coefficient of performance (COP) in the electric load mode. The system's exergy and energy efficiency are higher in the following electric load mode, and the equipment with higher exergy loss includes LCPV/T, gas-fired boiler, absorption refrigeration unit, MGT, and hot water generator.