Thermoeconomic analysis of an integrated combined cooling heating and power system with biomass gasification

摘要

Integrating combined cooling, heating and power (CCHP) system with biomass gasification is a sustainable distributed energy system to effectively utilize biomass resource and improve energy efficiency. In order to achieve a higher energy efficiency and more cost-effective operation, a thermoeconomic cost analysis method based on the exergetic cost theory is applied to the CCHP system based on biomass gasification. Firstly, the exergetic cost and thermoeconomic cost of all flows in the system are calculated in different operation modes. Moreover, a sensitivity analysis is presented to obtain the thermoeconomic cost variations of the products along with the influence factors, such as service life, interest rate, operation hours and biomass cost. The results indicate that the unit exergetic cost of electricity is 4.447, 4.445 and 4.447 for the summer, winter and transition season operation conditions, whereas the thermoeconomic cost is 240.004RMB/h, 257.905RMB/h and 270.811RMB/h, respectively, while for domestic hot water, these values are 14.822, 14.817, 27.086 and 33.361RMB/h, 35.769RMB/h, 166.284RMB/h, respectively. The unit exergetic cost of water for cooling and heating is 8.804 and 7.465, the thermoeconomic cost is 138.807RMB/h and 147.454RMB/h, respectively. From the sensitive analysis, the biomass cost is the most sensitive factor to the thermoeconomic cost of the products. The results also reflect that a combination of the thermoeconomic cost based on exergetic cost and sensitivity analysis method is a powerful and efficient tool for evaluating the performance of multi-product energy system.