The Influence Of Ambient Crosswind On The Cooling Performance Of Natural Ventilation Counter-current Wet High Water Intake Cooling Tower And Its Simulation

For a long time,the low quality heat energy is often ignored that contained in cooling circulating water in thermal power generation process.It is well known that the back pressure of the condenser is closely related to the thermal efficiency of the unit and is affected by the cooling circulation water temperature of the condenser,namely the condenser cooling inlet circulation water temperature drop per 1,the efficiency can improve 0.47% and 0.35% respectively for the medium pressure units and high pressure units.In addition,the operating hours of thermal power has decreased continuously since 2013,so it is urgent to improve energy efficiency and reduce energy consumption.The cooling tower is one of the important cooling equipment in the cold end of thermal power generation,which determines the inlet water temperature of the condenser.Therefore,this paper optimizes and analyzes structure of cooling tower to achieve the goal of reducing the out-water temperature of the tower through numerical simulation.Firstly,the mechanism of heat and mass transfer of air-water and working process in wet cooling tower is analyzed.The 3d model of the cooling tower of 1000 MW thermal power unit is established by combining the characteristics of 1000 MW thermal power unit.The simulation results show that the temperature difference between the calculate value and the actual value is 0.35?,and the margin of error relative to total temperature drop was 3.4%.Because the smaller relative error,the model is considered reasonable.Secondly,the structure of the cooling tower is analyzed and optimized,and the distribution of air flow in the cooling tower is not uniform.In this paper,it is suggested that make the air-distribution in cooling tower reasonable from two aspects of water distribution as well as the packing layout optimization.The method of partitioning water distribution is proposed,and the spraying surface is divided into two regions including in and out regions so as to set different water density.The water temperature of cooling tower rises first and then increases as the area ratio increases and the water density decreases.The distribution of temperature,velocity in the tower tends to be uniform.Moreover,the operating conditions such as the water flow rate of circulating water,air dry bulb temperature,relative humidity are changed under water distribution and summaries the various factors on cooling tower cooling performance under different operating conditions.Finally,when the speed of crosswind is 2m/s,4m/s,6m/s,8m/s respectively,the influence of the crosswind on the cooling performance for the cooling tower was analyzed.When the speed of crosswind is 8m/s,the cooling tower has the weakest cooling performance and the rising water temperature is 1.12?.The arc guide plate is installed in the inlet to improve the influence of environmental side wind,and the influence of the installation quantity and installation angle of the guide plate on the cooling performance is summarized in this paper.The calculation results show that the arc guide plate can effectively rotate the air flow along the guide plate and weaken its impact on the air in the leeward area.