| 内容提要: |
In district heating technologies, gas fired boilers and conventional heat pumps have poor performance at low ambient temperature. To tackle this issue, this study has proposed a novel air-source gas-fired absorption heat pump for district heating with flue gas recovery. Compared with conventional absorption heat pumps, the proposed solution in this study can absorb heat from both air and flue gas. Additionally, the working fluid works properly when air temperature is below 0 °C, safe and nonflammable. To analyze the economic and the thermodynamic performance of this air-source gas-fired absorption heat pump, a mathematical model, considering energy, exergy, economy and environment, has been developed. According to the simulation results of the model, the proposed air-source gas-fired absorption heat pump system here had good stability and feasibility under various operational conditions. However, as the payback period and the exergy destruction were found to be conflicting with each other, a multi-objective optimization method was established to minimize the system’s payback period and exergy destruction simultaneously. Additionally, the technique for order preference by similarity to an ideal solution decision-making method has been applied to look for the optimal solutions in the Pareto frontier, with optimal solutions of the system under different operational conditions recommended. |