Research On Low-pressure Solution Regeneration Of Heat Source Tower Heat Pump System Based On Heat Storage

With the rapid development of the building industry,the total energy consumption of the building is increasing day by day,and 50%～70%of the building energy consumption is used for building air-conditioning,among which the energy consumption of cold and heat source accounts for the largest proportion,so it is crucial to reduce the energy consumption of cold and heat source.As a new type of energy system,heat tower heat pump system can be used in winter and summer improving equipment utilization rate and protecting environmental.However,as the refrigerant carrier of the heat tower heat pump is an antifreeze solution in winter,the solution will absorb moisture in the air during the heat exchange process,leading to a decrease in concentration and an increase in freezing point.Long-term operation will lead to the risk of freezing the system.In order to solve this problem,this paper proposes a method of heat regenerative to improve the solution concentration.Firstly,this paper is based on a running example of heat source tower of a building in winter,theoretical analysis under different weather,air inlet humidity,entrance solution temperature effect on the heat source tower of condensate water,then through the experiment measurement the heat source tower air and solution in and out of the tower building runtime parameters and calculate the condensate water from December 24,2017 to January 31,2018,through comparison between the experimental and theoretical data to verify the accuracy of the heat source tower model of condensate.At this time,it was found that with the increase of the relative humidity of the inlet air,the amount of condensate needed would also increase,while the increase of the temperature of the solution at the inlet of the heat source tower would reduce the heat absorption and the amount of condensate of the heat source tower.Secondly,the model of solution regeneration system for heat tower heat pump was constructed,and the working principle of the model in two working conditions(normal working condition and heat storage working condition)and the feasibility of heat storage and regeneration were analyzed.Then,the system model was verified by comparing the simulated condensate volume with the actual condensate volume through the regeneration device.Finally,according to the heat source tower heat pump solution regeneration system model,the effects of different inlet air humidity,inlet solution temperature,heat storage capacity of heat storage device,vacuum degree of regeneration device,hot water flow,heat storage area on condensate volume and system performance were studied.At this time,the study once again verified that the condensate volume in the solution regeneration system of heat tower heat pump increased with the increase of air inlet humidity and decreased with the increase of solution inlet temperature.And when the vacuum pressure rises from 4.90kPa to 5.20kPa,the condensate volume rises from 89.78g/s to 102.62g/s.And with the hot water flow rate of the heat storage device water increased from 8.70 kg/s to 9.10 kg/s,hot water inlet temperature of the heat storage device increased by 39.87℃ to 40.10 0C,boiling temperature rising from 34.83℃ to 35.16℃.The condensation water increased from 73.28g/s to 83.07g/s.Heat transfer capacity of the heat storage device increased from 183.82kW to 208.11kW.In the standard working condition,the condensate amount of the heat storage device is only 74.99%of the regenerated condensate amount,and 1.33h of heat storage is required to meet the requirement of condensate amount.With the increase of heat storage area,the temperature of hot water inlet and outlet,the boiling temperature of solution,the heat storage and the amount of condensate all show an upward trend.