衡量背压式热电联产热经济性的改进式热量分析法OA

With the increase of requirements for energy conservation and consumption reduction,back-pressure combined heat and power(CHP)systems have developed rapidly.To clarify and unify the indicators characterizing the thermo-economy of back-pressure CHP,investigation was carried out for its thermodynamic performance based on heat balance method.The heat rate was selected as the evaluation indicator and was applied to various cases of pure condensing power generation,and the rationality of this indicator,along with its defects and irrationalities when evaluating the thermo-economy of back-pressure CHP,was analyzed comparatively.Subsequently,an improved heat balance method was employed to compare different CHP schemes.The results indicate that for pure condensing generation units,the heat rate decreases with the improvement of steam inlet parameters and the adoption of single or double reheat cycles,however,the heat rate fails to accurately reflect the performance improvement in back-pressure CHP systems resulting from enhanced steam inlet parameters and improved turbine cylinder efficiency.In contrast,for back-pressure CHP units,the heat rates calculated using equivalent power method and saturated enthalpy method can effectively demonstrate the improvement of energy utilization levels attributable to parameter enhancements and increased turbine efficiency.These findings can provide reference for thermo-economic evaluation,indicator selection and design optimization of back-pressure CHP units.