Performance Analysis Of Hybrid Cooling Tower Based On Effectiveness-NTU Approach

Electric power industry is related to the lifeblood of the national economy.To achieve energy-saving power generation process for the implementation of energy-saving emission reduction in China is of great significance.In addition to the proximity of water power plants may be used to provide a low-temperature heat source for the heat cycle,the majority of power plants will use air cooling system or wet cooling system to provide cooling water supply of low-temperature heat source.The hybrid(dry/ wet)cooling system has the advantages of wet cooling system and air cooling system,which has become an important direction for the future development of power station cold end optimization technology.Based on the effectiveness-NTU(ε-NTU)method,a mathematical model is set up for the hybrid cooling system which is used in power plants.With this model,the characteristics of the hybrid cooling tower in adjusting outlet water temperature of the cooling tower and influencing steam turbine back pressure are studied.The applicability of hybrid cooling system in different regions of China is analyzed with regional meteorological data.The results indicate that the hybrid cooling system helps to solve the problem of increased back pressure and reduced energy efficiency of air-cooled power plants in summertime by effectively lowering the temperature of circulation cooling water.Overall the hybrid cooling system is more appropriate to be applied in the area with proper humidity.In addition to using a variety of series and parallel operation mode of the wet and dry system in different temperature,humidity and wind speed under natural conditions,detailed research is also made.The research of this paper has important reference value for the stability and safety of the using hybrid cooling system,and also can provide the technical support for the selection of hybrid cooling system.