Applicability Analysis Of Indirect Evaporative Cooling Heat Recovery Heat Pump In China

The research indicates that the load of fresh air can often account for more than30% of the total load of air conditioning in some places with a large demand for fresh air,so it is of great significance to reduce the energy consumption of fresh air.In order to strike a balance between ensuring indoor air quality and reducing building energy consumption,the exhaust heat recovery heat pump technology emerges as the times require.Its working principle is to recycle the high-grade energy in the exhaust air,so as to improve the performance coefficient of the heat pump.According to whether the fresh air and exhaust air heat exchange before entering the heat pump unit,they are divided into single heat and double heat recovery heat pumps.The system performance coefficient of double heat recovery heat pump is better than that of single heat recovery heat pump,but the performance coefficient of its heat pump unit is lower than that of single heat recovery heat pump.The reason for this is that the exhaust and fresh air of the double heat recovery heat pump need to have a heat exchange first,which reduces the high-grade energy available in the exhaust.For example,in summer,the exhaust air temperature will be high,which will worsen the working environment of the condenser.According to the research,indirect evaporative cooling heat recovery technology can effectively reduce the temperature of fresh air in summer,on the other hand,it can ensure that the exhaust temperature is not too high.Therefore,this paper proposes a new type of indirect evaporative cooling exhaust heat recovery heat pump by combining this technology with double heat recovery heat pump.In this paper,first of all,through the relevant theoretical analysis and reasonable assumptions,the mathematical model of the relevant components of the heat pump with heat recovery is given.Then,the experiment of the equipment is carried out in summer and winter,the experimental results show that the new fan maintains a very high energy efficiency ratio both in summer and winter.After that,this paper uses MATLAB to model the heat pump type heat recovery fresh air unit in a modular way,and uses the experimental data to verify the model.Finally,based on TRNSYS software,a simulation platform for dynamic load simulation and unit operation simulation is established.Furthermore,using the platform to simulate and analyze the annual effect of heat recovery heat pump fresh air fan in typical cities(Liupanshui,Chongqing,Guangzhou,Zhengzhou and Shenyang)in different climate areas,and optimize the relevant operation control strategies.The results show that: this novel heat pump has different characteristics under different climate conditions.In the application of Liupanshui,it has greater energy-saving advantages.Considering that the adaptability of some modes is somewhat lacking,the overall application is in a good state.As for Guangzhou and Shenyang,although the combined operation of heat recovery unit and heat pump unit can give full play to its advantages in heating or cooling,in many cases,additional cold and heat sources are required for auxiliary cooling or heating,so the economy and adaptability of these two regions are limited to a certain extent and their overall application is in a moderate state.The application of heat recovery heat pump in Chongqing and Zhengzhou has both adaptability and economy,so it can be popularized in the future.In addition,the traditional air source heat pump system and air source heat pump system with exhaust heat recovery are taken as the comparison items.Through simulation,it is found that compared with these two systems,the energy saving rate of heat recovery heat pump system in each city is more than 30% and 20% respectively.