Anti-freezing characteristics and margin of indirect air-cooled finned tube bundle
The anti-freezing operation parameters of indirect air-cooled finned bundle are insufficient at present.To solve this problem,this research firstly concludes the anti-freezing model of finned tube bundle,including the thermal equilibration equations,water side and air side transport equations,as well as anti-freezing constrains.Secondly,based on the co-current and counter-current air-cooled finned tube bundles,the critical anti-freezing characteristics and margin are analyzed.Then,the critical values are discovered for finned tube bundles with middle inlet,left inlet and side inlet patterns.The research shows that,as the ambient temperature or inlet water temperature reduces,as well as the ambient wind increases,the critical anti-freezing water flow rate ascends.Besides,when the inlet water temperature decreases,the wind effects get intensified.The anti-freezing performance of counter-current finned tube bundle is inferior to that of the co-current type,meanwhile the difference becomes expanded if the wind increases or water inlet temperature decreases.The effects of inlet water temperature elevation on anti-freezing margin can be classified into three levels,which are termed as obvious range(0 ℃,10 ℃],slow range(10 ℃,20 ℃],and stable range(20 ℃,40 ℃].Therefore,power plants should not always increase the water flow rate for anti-freezing operation.The air-cooled finned tube bundle with middle inlet pattern has better anti-freezing performance than others,so it's suggested preferentially for coal-fired or nuclear power plants.This research may provide guidelines of anti-freezing operation for dry-cooling power stations in China.
air-cooled finned tube bundleanti-freezing model of finned tube bundlecritical anti-freezing water flow rateanti-freezing marginwater inlet pattern of tube bundle
万方数据
维普
