Study On Heat Transfer Performance Of Evaporative Condenser And Its Energy Consumption Compared With Air-Cooled Condenser

Air-cooled air-conditioning is widely used because of its convenience in installation,no need for controlling room,water saving and other advantages.However,with the increase of outdoor temperature in summer,air-cooled air-conditioning will have problems such as lower efficiency and higher energy consumption.Water-cooled air conditioner consume large quantity of water so that it need special cooling towers and cooling water pumps.Therefore,it is necessary to study a water-saving,energy-saving and small-sized condenser.The evaporative condenser can effectively solve this problem.Evaporative condensers have received attention in the field of HVAC due to the above advantages.However,most of the research contents of scholars are under specific conditions,it is not practical for general problem.In this paper,a dual-purpose condenser combined with air-cooled and evaporative is used.The dual-purpose condenser is installed on a test bench with an independent air handling system to test its heat transfer performance.Based on orthogonal experiment and single factor experiment,the experiment was further improved to simulate the outdoor environmental parameters of Changsha in summer.Under the cond:itions of higher temperature and higher humidity,the power consumption of the compressor of the evaporative condenser and the air-cooled condenser was studied by comparative experiment.The influence of inlet air humidity,inlet air temperature and sprinkler water quantity on heat transfer performance and energy saving efficiency of evaporative condenser is studied.The relationship between the compound heat transfer coefficient of the evaporative condenser and the inlet air temperature is obtained,which provides a reference for further study.Based on the analysis of experimental data,the following conclusions are drawn:(1)The influence of inlet air humidity on the power consumption of the compressor is very small.The inlet air humidity increases from 70%to 80%at 33?,and the power consumption is reduced by 5W.(2)Under the same other parameters,the energy consumption of the compressor decreases first and then increases with the increase of spray water,and increases with the increase of inlet air temperature.The energy saving efficiency of the compressor increases first and then decreases with the increase of spray water,and changes slowly with the inlet air temperature.(3)The primary and secondary relationship of the factors affecting the power consumption of the compressor is:spray water volume,inlet air temperature,and inlet air humidity.(4)The optimum spraying water quantity of evaporative condenser is different at different inlet air temperature.The optimum spraying water quantity is 16L/h at 33?and 34?,17L/h at 35? and 36?,and 18L/h at 37? and 38?.(5)The composite heat transfer coefficient outside the tube of evaporative condenser decreases with the increase of inlet air temperature,and increases with the increase of spray water.The variation range of the composite heat transfer coefficient is122-163W/m2·?.