Experimental Research On Three Dimensional Thermal Performance Evaluation And Wind Control Strategy Of Indirect Air Cooling Tower

Because of its remarkable water-saving characteristics,air-cooled systems are widely used by countries and regions in the world,especially in areas where water resources are scarce and coal mines are abundant.Under normal circumstances,the waste heat generated by the exhaust steam of the power station steam turbine is indirectly exchanged in the condenser through the cooling circulating water and discharged through the wet cooling tower.During this process,a large amount of cooling circulating water is evaporated,and the system is called wet cooling.System,however,the emergence and development of air-cooling technology has provided a new water-saving,economical,safe,and reliable way for the construction of large-scale thermal power stations in areas of severely water-poor coal mines and power load centers.Since the air-water heat transfer is non-contact heat transfer,there is no evaporation loss of the circulating water,so the indirect air-cooled system has significant water-saving characteristics.However,the cooling limit of the circulating water in the indirect air-cooling system is the dry air temperature of the ambient air,so that the substantial reduction of the water consumption of the air-cooled unit is based on the high consumption of coal.Therefore,the indirect air-cooling system has obvious water-saving characteristics compared to the wet-cooled units due to the different heat exchange modes,but at the same time,it also has inherent defects of the system itself.That is,the cooling efficiency is low,resulting in high back pressure and being easily influenced by the external environment.Unit coal consumption increased.How to reduce the coal consumption of air-cooled generators,stabilize the unit back pressure,and reduce the influence of the external environment,especially the ambient wind,on the cooling towers,is the engineering problem faced by the air-cooled power stations,and is also a scientific problem faced by air-cooled technicians.The starting point and ultimate goal of this project is also the same.Through the thermal model test,the environmental meteorological conditions,especially the effect of ambient wind on the air flow and heat transfer characteristics of indirect air cooling towers,are evaluated.The three-dimensional thermal performance of indirect air cooling towers is evaluated and evaluated.On this basis,a reasonable wind control strategy is proposed to improve the cooling efficiency,and finally the experimental simulation analysis,performance evaluation and efficiency optimization of the three-dimensional thermal performance of the indirect air cooling tower are achieved.Based on the actual air-cooled tower type,local meteorological conditions and other relevant data,this paper establishes a thermal model test rig according to certain similar criteria,so that the water temperature,water temperature,ambient temperature and humidity,side wind speed and other factors can be controlled.For different units,different radiators are arranged,under typical conditions,the thermal performance under windless and crosswind is studied.Firstly,the typical working conditions of the unit,the basic experiment under no wind condition,the size and distribution characteristics of the wind speed entering the tower around the air cooling tower,the temperature values and distribution rules of the radiator water in and out at different locations,and the basic data and the time of crosswind optimization After the data relative ratio.Secondly,under the condition of crosswind,the performance parameters such as cooling temperature difference and inlet tower wind speed change with the side wind speed at different locations around the air cooling tower,and analyze the influence of the crosswind on the performance of the air cooling tower,which provides a basis for the optimization and reform measures.Starting from the weakening of this adverse effect,the use of wind deflectors and cross partitions to optimize the thermal performance of intercooled towers under crosswind conditions.Renovation tests were conducted on the intercooling towers of different radiators in different units,and the improvement of the two wind control strategies of the air deflector and the cross partition was compared.According to the one-dimension heat and resistance calculation model of the air cooling tower,and based on the three-dimensional numerical calculation results,the tower can be extracted under certain input conditions for different ambient temperatures,ambient wind speeds,temperature inversion conditions,and water inlet parameters of the tower.Iterative calculation of water temperature.Since the one-dimensional model has a simpler algorithm and does not require much preparation,the one-dimensional model can more quickly realize the evaluation of the thermal performance of the cooling tower.