Coupling Study On Two Methods Of Dry Air Cooling

Recently,the development of air-cooling technology become the main way to solve the problem of "coal rich and water shortage".It is hot in summer and windy in spring and autumn in the northern part of China,so the heat dissipation capability of the direct air cooling system is obviously insufficient due to the increasing ambient temperature and decreasing of the inlet air flow rate.Besides,the fin tube fouling,corrosion and other issues caused by the long time operation lead to the reducing air condenser cooling capacity and the increasing unit back pressure.Therefore,it is necessary to optimize the cold end of the direct air cooling system and enhance the thermal capacity of the unit in the environment of high temperature and strong wind.Based on the environmental conditions and unit operating conditions of Fugu Power Plant,two dry air-cooling coupling systems based on direct air-cooling and Heller-type indirect air cooling are proposed in this paper.The principle,operation mode and characteristics of the system are introduced in detail,and the heat distribution of the two cooling systems is investigated.According to the running performance of the coupled system,the mathematical model of the main part(jet condenser)of the coupled system is established,and the thermodynamic calculation and variable working condition are carried out to study the influence factors of the heat transfer coefficient and end difference of the jet condenser,also to minimize the end difference of jet condenser and improve the operating performance of coupling system.Based on the design and actual operation data of the power plant,the optimization of the design condition by the coupling system is analyzed.According to the calculation of variable working condition,the optimization for different operating conditions by the coupling system and the sensitivity of the ambient temperature and wind speed to the backpressure of the coupled system are analyzed.Furthermore,the economic performance of the coupled system under different pumping conditions is studied,which can guide the energy saving and optimization of cold end of the power plant.