Research On The Technology Of Cooling Condenser With Spray Of Condensate Water In Railway Buildings

Air conditioning energy consumption in the proportion of total energy consumption in railway passenger station is large.Air-conditioning systems have always been the focus of research on energy-saving and emission reduction of railway passenger stations.During the air conditioning and cooling operation,the evaporator will precipitate condensed water,and the larger the air conditioning refrigeration capacity and the greater the wet load,the more condensed water will be produced.These condensed waters have low temperature and low impurities and can be used as a cold source.Due to the large flow of personnel in the railway passenger station,the air conditioning cold load is large in summer,and the indoor personnel has a large wet load.The air conditioning condensate is produced in considerable quantities,and the air conditioning system of the railway passenger station uses the full air system,and the condensate recovery is convenient.It can be seen that the air conditioning condensate of the railway passenger station has greater energy saving and water saving potential.In this paper,through the combination of theoretical calculation,experimental research and computer simulation,the technology of using air-conditioning condensate to spray-cool the air-cooled condenser to improve the performance of the air-conditioning unit is studied.The specific research is as follows:By studying the theoretical calculation of condensed water production and condensed water production,and using a small railway passenger station as a model,the air conditioning condensate production in summer in Beijing,Shanghai,Xi'an,Guangzhou and other regions was calculated,respectively,338.05t,218.57t 114.95t and129.31t,it is concluded that the recovery of air-conditioning condensate in the eastern and southern regions of China(high temperature and high humidity)is greater and the utilization is greater.Through theoretical analysis of the heat and mass transfer process of the condensate spray cooling condenser,it is found that spray cooling can greatly improve the heat transfer coefficient of the condenser,but the specific benefits need to be experimentally studied.The experiment of cooling the condenser by air-conditioning condensate spray was carried out to study the effects of different outdoor temperatures and different spray amounts on the energy-saving effect of air conditioners.The research results show that the sprayed condensate can be sprayed onto the surface of the condenser,which can improve the cooling capacity and COP of the air conditioning unit,and the higher the outdoor dry bulb temperature is,the more obvious it is.In the range of experimental spray(9.33 L/(h·m~2)~47.92 L/(h·m~2)),the outdoor dry bulb temperature is 30°C,35°C and 40°C,respectively,and the condensation temperature of the condenser is reduced respectively compared to the unsprayed state.At 4.9°C,5.3°C and 6.0°C,the maximum cooling capacity increased by 3.2%,4.8%and 6.1%respectively.The maximum input power of air conditioning units decreased by 7.6%,9.2%and 10%respectively,and the maximum COP increased by 11.0%.15.2%and 17.9%.By setting up the cooling model of LMS AMESim air conditioning unit,the influence of condensate utilization device on the performance of air conditioning units under different outdoor dry bulb temperatures was studied.Using the simulation model to simulate the hourly energy consumption of air conditioning in a small railway passenger station in summer,compared with the power consumption of the air conditioning unit before and after the application of the spray device,the energy saving in summer is 5.53%.In view of the problem of insufficient air conditioning condensate,the economics of the water supply of the spray device is analyzed.It is concluded that when the spray volume of a single air conditioning unit is 18.06L/(h·m~2),that is,the water supply is 114L/h,and the total summer water supply is 476.52t.The spray device saves the maximum cost,and the cost savings are 7.48%of the total cost compared to the unsprayed condition.