某引进型600 MW汽轮机高压外缸温差过大现象的剖析

上海某汽轮机厂引进美国西屋公司技术制造的600MW汽轮机，在昊泾第二电厂和山东聊城电厂的运行中，均存在高压外缸中间处上下部积水温差过大的现象，而且已经超过厂家给定的跳闸值。针对这种情况，根据其高压缸的结构特点，分析了高压缸运行时蒸汽流动的传热情况，并对这种高压缸温差过大的现象进行了解释，最后提出了相应的措施。由于台山发电厂的汽轮机属于同一类型，因此对汽轮机作了改进，解决了高压外缸上下缸温差过大的问题。

Analysis on high temperature difference in HP outer casing of a certain imported-type 600 MW steam turbine

The 600 MW steam turbines operating in Wujing No.2 Power Plant and Shandong Liaocheng Power Plant were made by some turbine factory in Shanghai based on the technique of Westinghouse Electric Corporation of US, which experienced large temperature differences between the upper and the lower parts of the HP outer casing, and the temperature differences overran the trip setting of the manufacturer. Based on the structural features of the HP casing, this paper analyzes the heat transfer of the steam flowing in the HP casing in operation, explains the reasons of the problem and presents countermeasures. Modifications were made on the steam turbines of the same type in Taishan Power Plant and satisfactory results obtained.