Analysis On Air-cooled Renovation Project Of600MW Units In Zhangshan Power Plant

The company of Zhangshan put two600MW generating units into operation in2008.Steam turbine exhaust cooling system uses three rows of tube bundles of direct aircooling system. Single unit air cooling radiator area is1280000square meters. Units’designed back pressure is15.0Kpa under THA conditions, and34.0Kpa under TRLcondition. According to the operation of the unit for three years, The back pressure isgenerally high in the condition of TRL and the operation economy of the unit is poorwhen in summer. When the ambient temperature is about30℃, the unit running backpressure has been up to40Kpa.As a result, it is necessary to reform the air coolingsystem. In order to reduce coal consumption, make the600MW direct air-cooled unit’sfull steam drainage back pressure maintained at15Kpa in summer。Moreover，the reformhas certain reference significance and guiding significance for the same type air coolingsystem.1、On the basis of the analysis of ZhangShan power company’s600MW unit air-cooledstructure and parameters, the preliminary design of the two retrofit schemes is given.With the cooperation of Zhangze Power company the project use circulating watersystem to construct the open cycle peak system and closed cycle peak system and selfcirculating water system, the system consist of reconstruction design scheme includingair cooling parts, engine, hydraulic technology, chemical water treatment, thermal control,electrical, civil, circulating water supply and return pipes etc.2、The third reconstruction schemes of transformation air cooling part of600MW unitin Zhangshan power company is given, which is called the evaporative coolerconstruction peak system. Thorough analyze the characteristics, working principle anddomestic application situation of the evaporative cooler. Detailed technical requirementsof each part of the evaporative cooler, cooling water; condensate water the thermalcontrol, civil engineering is given.3、Technical and economic comparison results of the three rehabilitation programs isgiven. The recovery period of Open cycle peak system, closed cycle peak system andevaporative cooler construction peak system were3.7years,4.2years and2.1yearsrespectively. The project finally adopts the construction of evaporative cooler system onthe two units of600MW air cooling system transformation. Evaporative cooler isarranged in the air cooling platform below or around. There is no noise and no waterenvironmental dispute problems because the company is far from the residents.4、Based on the consideration of multiple factors, this paper put the No.4units ofZhangshan company600MW unit as the object of study, to evaluate the operation economy of evaporative cooler system. This paper has proved the reconstruction schemeof evaporative cooler system achieves the goal of saving energy, and greatly ensures thesafety, economy and efficiency of Unit operation. It has great significance in direct aircooling unit field, and possess very high popularization value in practice.