Research On Key Technologies Of Full Heat Exchanger Performance Test Experimental System Based On Thermoelectric Heat Pum

With the rapid development of industrialization,the energy demand of human society has increased significantly.For the purpose of reducing energy consumption,researchers have gradually become interested in thermoelectric technology in recent years.The Peltier effect is a kind of semiconductor thermoelectric effect,which can realize the conversion between heat energy and electric energy.When a current passes through a circuit composed of different conductors,in addition to generating irreversible Joule heat,heat absorption and heat release will occur at the joints depending on the direction of the current.A thermoelectric element composed of multiple sets of thermocouples can transfer heat from one side to the other,so it can be used as a heat pump,called a thermoelectric heat pump.Thermoelectric heat pumps have the advantages of high reliability,no mechanical moving parts,small size,and easy operation.Therefore,from the perspective of energy saving,it can be considered to use both cold and hot sides of thermoelectric heat pumps to achieve energy saving purposes.The total heat exchanger is usually used as an energy recovery device,and its characteristic is to realize the total heat exchange between air and air,and both heat transfer and humidity transfer occur.In the production and development process of total heat exchangers,the performance test of heat and mass transfer is an important part.The key to the performance test experiment of the total heat exchanger lies in the creation of different air sensible heat conditions and latent heat conditions,which is the focus of this paper.Based on the consideration of the simultaneous use of both cold and hot sides of thermoelectric heat pumps,this paper proposes a method of air circulation combined with heat recovery in thermoelectric heat pumps,which aims to improve heat production efficiency and energy utilization of heat pumps,and is applied to the performance test of sensible heat cross-flow heat exchangers At the same time,based on the need for coordinated regulation of temperature and humidity conditions in the total heat exchanger test experiment,the use of thermoelectric heat pumps was explored in the direction of humidity regulation.The main research contents are as follows:Firstly,combined with air circulation and heat recovery,a sensible heat exchanger test system design based on a thermoelectric heat pump was carried out.Through the thermodynamic analysis of the system,it can be concluded that compared with the traditional heat exchanger test device,the energy-saving effect of the system is mainly reflected in two aspects: the return heat of the heat recovery heat exchanger and the heat absorption of the cold side of the thermoelectric heat pump.Corresponding to two energy-saving means of heat recovery and heat pump air circulation.The method was applied to the performance test of the cross-flow sensible heat exchanger,and an experimental device was built to conduct a series of experiments with variable working conditions.Secondly,an experimental analysis of the performance of the cyclic thermoelectric heat pump combined with heat recovery was carried out.In the heat pump air circulation experiment,the heating efficiency(COP)of the thermoelectric heat pump with air recirculation is up to about 3.7.At an air velocity of 1 m/s,the COP of the heat pump with air circulation was 51%-73% higher than that without air circulation.In system experiments for heat exchanger test applications,the heat recovery of the heat recovery heat exchanger accounts for up to 12% of the total heat production.The combination of heat recovery and air circulation improves the energy utilization efficiency of the heat exchanger test system,and the highest energy efficiency ratio reaches 2.85.The performance test of the sensible heat exchanger,it shows that the experimental device of the heat exchanger test system can provide experimental conditions within a certain range,and the basic functions of the system can be realized.On the basis of the experimental data,the heat transfer performance of the tested eight heat exchangers is compared and analyzed comprehensively.Comparing the test experiments of 3mm heat channel and 5mm heat channel heat exchanger,it can be found that under the same working conditions,the heat transfer capacity of 3mm heat exchanger is relatively higher than that of 5mm heat exchanger,but the total heat transfer coefficient is relatively smaller.It can be observed from the experimental results that as the wind speed increases,the influence of the thermal conductivity of the heat exchanger separator on the heat transfer performance of the heat exchanger becomes smaller,while the opening of the corrugated plate enhances the heat transfer performance.Finally,in order to realize the adjustment and control of the air humidity,the silica gel desiccant and the thermoelectric heat pump are used in the humidity control by using the adsorption characteristics of the silica gel desiccant,and the experimental device is built,and the experiments of the single control and double control methods are carried out.The two humidity control methods of single control and double control can make the relative humidity of the air fluctuate around the target and achieve relative stability.Under each experimental condition,the maximum relative humidity offset between the single control and the target value is 3%,and the maximum relative humidity offset between the dual control is 3.3%.Comparing the experimental results of single control and double control,double control has better response speed than single control,so it has more potential.According to the experimental results,the fluctuation range of humidity control is related to thermal inertia.Therefore,in further research,an automatic control method can be introduced to dynamically change the judgment criteria of positive and negative adjustments to reduce the influence of thermal inertia,thereby improving the accuracy of humidity control.In the experiment,it is found that the change of air temperature and relative humidity presents a weak correlation,which can realize the independent control of air temperature and humidity,which provides data support for the coordinated adjustment control of the two working conditions of air temperature and humidity of the total heat exchanger.The optimization of air circulation and heat recovery on the performance and energy efficiency of thermoelectric heat pumps is verified through sensible heat exchanger test experiments.At the same time,through air humidity control experiments,explorations are made in the field of humidity control of thermoelectric heat pumps.This study has reference significance in the fields of thermoelectric technology application and total heat exchanger development research.