Optimum Design For Low Temperature Economizer System Of 1000MW Ultra Supercritical Air-cooled Power Plant

This paper mainly described three common low temperature economizers in the domestic thermal power unit, including the system type and characteristics. The influence of some main factors on the typical design of low temperature economizer system was also summarized. In this paper, the author took the 1000 MW ultra supercritical air cooling thermal power unit in Shanxi Shentou power plant as an example, and designed four different schemes for the condensate water system. According to the calculation and analysis results, the fourth scheme exhibited higher thermal efficiency that other three schemes. In the fourth scheme, based on the idea of energy cascade utilization and considering security and reliability, the author designed a two-stage heating pipe system and put the two levels of low temperature economizer in tandem arrangement on the entrance of the desulfurization absorption tower flue. The low temperature economizer A, which was arranged in the high temperature flue gas, was used to heat the condense water in the high temperature stage. The low temperature economizer B in the low temperature flue gas was used to heat the condense water in the low temperature stage. In addition, the heat exchange tube bundle of economizers can successfully avoid the erosion wear caused by the high dust concentration and hence increase the service life safety of the equipment since the two levels of low temperature economizers were both arranged at the downstream of the dust collector.The optimized schemes of low temperature economizer system proposed in this work have a high application value for both Shanxi Shentou power plant and other similar plants. So does the design of low temperature economizer system summarized in this paper, which also contributes a lot to the engineering application of these plant units.