采用喷射泵疏水方式的回热系统热经济性分析

摘要

This paper introduces the present basic drain methods of the regenerative system in condensing steam turbine, and the merit and demerit were dissected.The working principle of water jet pump was introduced, and a calculation model of fluid flow of the water jet pump was built.A new drain method using water jet pump was put forward, and the principle thermodynamic energy system with the new drain method was draw up.The enthalpy of mixing of water jet pump outlet was determined, and the calculation model of economical indexes of unit based on the thermal balance method was built.Take a 300MW turbine unit as an example, the jet coefficient of water jet pump was calculated, and the economy was compared along the different methods about drainage use, the results shown that the drain method of water jet pump activity was higher in thermal economy than the drain method of flow automatically through each stage.%介绍了目前凝汽式汽轮机组回热系统的基本疏水方式,分析了其优缺点.介绍了喷射泵的工作原理,建立了喷射泵工作流体流量的计算模型.提出了采用喷射泵的回热系统疏水方式,拟定了采用喷射泵疏水方式后机组的原则性回热系统简图.基于常规热平衡法,确定了喷射泵出口混合焓,并建立了机组热经济性指标的计算模型.以某300MW机组为例,计算了喷射泵的喷射系数,并对采用不同疏水方式机组的热经济性进行了比较.结果表明,采用喷射泵疏水方式机组的热经济性明显高于采用逐级自流疏水方式机组的热经济性.