电厂凝汽器水室分隔余热回收技术探讨

Discussion on Waste Heat Recovery Technology by Separating the Water Chamber of Condensers

利用自行开发的凝汽器数值模拟软件对某电厂2×350 MW机组的凝汽器在冬季额定抽汽供热工况下的热力性能进行了数值仿真.通过对凝汽器水室进行分隔,将出口温度较高的冷却水引入吸收式热泵装置进行余热回收.结果表明:传热系数和冷却水出口温度在凝汽器不同冷却区域有明显差异.在冬季额定抽汽供热工况下,采取凝汽器水室分隔措施会提升余热水的余热温度和余热;余热水的质量流量越大,则余热水出口温度越低,余热量越大;余热水回水温度越高,则余热水出口温度越高,余热量越小.在夏季工况下,凝汽器水室分隔基本不改变其热力性能.

The thermal performance of two condensers in 2×350 MW power units was numerically studied using self developed simulation software under rated winter extraction heating mode. By separating the water chamber of condensers, cooling water with higher outlet temperature was led into an absorption heat pump for waste heat recovery. Results show that both the heat-transfer coefficient and cooling water outlet temperature are quite different in different condenser cooling regions. Under rated winter extraction heat- ing mode, the temperature and exergy of waste water can be increased by separating the water chamber of condensers. The higher the waste water flow is, the lower the waste water temperature will be, resulting in increased quantity of waste heat. Tt^e higher the return water temperature is, the higher the waste wa- ter temperature will be, resulting in reduced quantity of waste heat. The division of water chamber hardly changes the thermal performance of condenser under summer operation conditions.