Application Research Of Tower Cooling Air-conditioning Technology In Lanzhou Area

With the development of social economy,China's urbanization has been accelerated,and the building energy consumption has been increasing year by year.In recent years,the state has vigorously promoted energy conservation and emission reduction,and created an environment-friendly society,which has promoted the emergence and use of energy-saving and environmental protection technologies in the field of building air-conditioning.Among them,the cooling chiller is disabled in winter or the transition season,Tower cooling technology that directly cools buildings with cooling towers can greatly reduce the energy consumption of air-conditioning systems,the energy-saving effect is significant,especially in dry areas such as Lanzhou.There are many achievements of tower cooling technology at home and abroad,but there are few engineering applications and effects that can be referred to,especially in lanzhou area.As the application performance and effect of cooling for tower cooling technology are closely related to the local climate conditions,the research results of engineering application of this technology in Lanzhou need to be supplemented and improved.To this end,this paper first briefly introduces the tower cooling technology;secondly,based on a hotel project in Lanzhou,the numerical simulation of the key equipment in the tower cooling system is studied.The cooling performance of opening cooling tower and closed cooling tower based on Lanzhou meteorological parameters is analyzed,and the performances of these two types of cooling towers are compared.Then,based on the meteorological parameters of Lanzhou,this article explores the applicable conditions of tower cooling technology in Lanzhou,and analyzes the energy-saving related factors in the system,including the cooling time and cooling temperature;Finally,this paper tests a hotel air-conditioning system in Lanzhou,and analyzes the energy-saving benefits of the hotel's tower cooling system.Through the research in this paper,the following conclusions are obtained:(1)Three-dimensional simplified models of opening cooling towers and closed cooling towers were established.The cooling performance of the two types of cooling towers was simulated and analyzed by using the FLUENT software and the air-liquid two-phase heat and mass transfer control program.The cooling performance of two types of cooling towers is correctly analyzed.Under the given simulation conditions,when the temperature is 9? and the air-inlet speed is 8 m/s,the cooling water at 15? of opening cooling tower can be cooled to 10.3?,the cooling water outlet-temperature of the closed cooling tower is 11.2?.(2)A mathematical model of the outlet water temperature of the closed cooling tower was established,and the temperature of the outlet water was calculated using MATLAB software under the given conditions.Under the given calculation conditions,the cooling water outlet temperature of the cooling tower in the transition season is basically below 10?.The simulation method is reasonable and effectively analyze and predict the energy saving effect of closed cooling tower cooling technology.(3)Based on meteorological parameters of Lanzhou,the wet-bulb temperatures of 4?,6? and 9? were used as the switching temperature points for tower cooling.The wet-bulb temperature below 4? cumulative hours available for cooling tower cooling total 3751 hours,wet-bulb temperature below 6? cumulative hours available for cooling tower cooling totals4275 hours,and wet-bulb temperature below 9 ? cumulative hours available for cooling tower cooling total 5213 hours.(4)For a hotel in Lanzhou that use tower cooling air-conditioning technology,when the tower cooling system is operated during the transition season,the minimum temperature of the outlet cooling water is 9.3?,and the maximum temperature of the outlet cooling water is12.7?.Further analysis of the operation time of the hotel's cooling tower cooling system.If the hotel's tower cooling system uses automatic switching,the theoretical power consumption that can be saved annually is 166918.9KW · h,which saves about 125189.2 Yuan in operating costs and energy saving rate is about 84.7%.