Comprehensive analysis and optimization of combined cooling heating and power system integrated with solar thermal energy and thermal energy storage

The introduction of solar thermal energy and the thermal energy storage are effective methods for reducing the fossil fuel consumption and improving the operation performance of combine cooling, heating and power (CCHP) system. In this study, a CCHP system integrated with solar thermal energy and thermal energy storage is proposed. The thermal energy storage device, which plays the role of energy hub, absorbs the solar thermal energy form the parabolic trough collector and excess thermal energy in the flue gas and then releases the thermal energy when necessary. Transient model of the system is established and the corresponding performance of the proposed system in the typical days are compared with those of the separated system and the conventional CCHP systems. The primary energy saving rate of the proposed system in the typical days of summer, winter and transition seasons are found to be at least 11 percent higher than the other CCHP systems. The capacity of the system is then adjusted for the best economy and corresponding thermal energy storage device capacity is found. Considering the peak-flat-valley electricity price, the operation strategy is then optimized and the equivalent levelized cost of electricity is reduced by 14.3%. This paper provides a viable option for improving the CCHP system performance and economy in solar-abundant regions.