Equivalent Enthalpy Drop Method with Application in a 330 MW Double Pumping Cogeneration Unit and its Thermal Characteristics Analysis

摘要

It is quite convenient and flexible to adopt the equivalent enthalpy drop method, in order to analyze a thermal system. In this report, a 330 MW cogeneration unit will be chosen, as a case in point, to provide quantitative calculation and qualitative analysis in both global and local aspects. According to our research, this cogeneration unit is designed to operate in a double pumping status. It has such properties as follows: Under 85% BMCR double pumping condition, its highest efficiency of power generation is obtained. In pure condensing conditions with around 70% load, the steam consumption rate reaches minimal level. The reason for this phenomenon lies in the maximal net equivalent enthalpy drop of new steam, although with 70% load, the power generation efficiency is much lower than that in rated pure condensing conditions.