Design Of Plate Pulsating Heat Pipe For Energy Recovery Of Air-conditioning Exhaust And Experimental Study On Summer Condition

With an increasing demand for energy,energy-saving has become a huge trend all over the world.For the weakness of cross contamination and change direction with the seasons of energy recycling of large building air conditioning,several kinds of plate pulsating heat pipes are designed.It is expected that the exhaust energy can be recovered efficiently on the basis of overcoming the defect.The fresh air is penetrated by the recovery of energy to reduce air conditioning system load and save energy.Several heat pipes are designed to simulate the start-up and heat transfer performance under the condition of summer only because of the short time,and analyse the influence factors on the start and heat transfer characteristics.The main factors include channel structure,equivalent diameter,air temperature,wind speed,and types of working fluid.The optimum heat pipe structure,design parameters and the type of working fluid of plate pulsating heat pipe are used for energy recovery in the air conditioner is analyzed and determined by experimental comparison,and the researchers obtained the following conclusions:(1)Four kinds of heat pipes with different structure and equivalent diameter has compared under the same experimental conditions,the equivalent diameter 3.11 mm of the quadrilateral parallel channel plate pulsating heat pipe in the 0 degrees installation angle has a better start effect.(2)Start-up experiment with water,acetone and R141 b,water and acetone start-up poor performance,and R141 b can start below 40 ?.It showed that the small surface tension,low latent heat of vaporization of the heat pipe is easier to start.The starting temperature of the condensing section was presented in order.It is indicated that the heat and mass transfer process in the heat pipe are gradually developed,rather than at the same time.(3)Effect of filling rate on start-up and heat transfer performance of a heat pipe is mainly as with the increase of liquid filling rate.The starting and heat transfer performance are enhanced and then weakened in the range of 15% to 30%.Optimum filling ratio is 25%.Under the same temperature,the higher the wind speed is,the higher the heat pipe heat transfer is,it can shorten start-up time.Start-up temperature has a downward trend.Equivalent thermal conductivity at 3.5m/s maximum,at 1.5 m/ s minimum.At the same wind speed,the heat pipe can be started when the fresh air temperature is higher than 34 ?,and the higher the temperature,the better the starting and the heat transfer performance.Analysis of the experimental data,start with a gradual smooth start and jump start two forms,but mainly for gradual smooth start.(4)Heat transfer efficiency is 43.1% when air through a single line along rows arranged in seven heat pipes of heat exchanger face velocities of 2 m/s,temperature of40 ?.