Research On Heat Transfer Process Of Low Temperature Differential Heat Recovery Heat Storage Heat Exchanger

In modern society where energy-saving and emission-reduction requirements are increasingly stringent,energy-saving in building air conditioning systems has become an important measure,and heat storage heat exchangers are a very effective heat recovery and energy-saving device for air conditioning fresh air system energy-saving.Compared with other heat exchangers,regenerative heat exchangers have the advantages of simple structure,low process level requirements,low cost,sensible heat and full heat recovery,etc.It is a heat exchanger with great application prospects.Recovery device.The main research content of this paper is to propose a new structure and operating mode of a regenerative heat exchanger.A combination of experimental exploration and numerical simulation is used to explore the thermal characteristics of a regenerative heat exchanger and to synthesize it.Performance evaluation and energy saving analysis.The main research contents and related conclusions of this article are as follows:(1)A new structure and operating mode of a regenerative heat exchanger is proposed,and a reversible axial fan is used as a running component.The heat storage structure that heats the heat is fixed and periodic heat storage and heat release are realized by changing the air flow direction.The regenerator uses a plate-shaped heat accumulator structure made of metal aluminum as a heat storage material.Experimental investigation shows that the heat recovery efficiency of the regenerative heat exchanger can reach more than 66%,and compared with the traditional sensible heat recovery heat accumulator the heat recovery efficiency of the regenerator is improved by 11%.The biggest advantage of the regenerative heat exchanger proposed in this paper is that the structure is simpler and easier to install.(2)The results of the structural parameters of the regenerator show that the length of the regenerator is the factor that has the greatest effect on the heat recovery efficiency.Within a length of 600 mm regenerator,the heat recovery rate will increased by more than 16% for every 100 mm,at the same time the heat transfer coefficient will be reduced by 6.9%,and the heat storage saturation time will be extended by an average of 21%.The effect of the distance between the heat storage fins on the heat recovery performance of the heat accumulator is phased.When the distance between the heat storage fins is less than 3mm,the heat recoveryperformance increases with the distance between the heat storage fins.When the distance between the heat storage fins is higher than 3mm,the heat transfer performance tends to be stable.Heat transfer performance is best when the distance between the heat storage fins is between 1-2 times the thickness of the heat storage fins.(3)The results of the study on the operating parameters of the regenerator show that the onset wind speed has a peak-like effect on the heat recovery performance of the heat accumulator,and the heat recovery efficiency is the highest at 4 m/s-6 m/s,reaching above60%,Below or above this range,heat recovery efficiency is reduced.The oncoming wind speed has a significant effect on the heat transfer coefficient of the heat accumulator.When the oncoming wind speed is less than 6m/s,the heat transfer coefficient of the heat accumulator increases by 38% for every 2 m/s increase in wind speed.(4)The temperature difference between indoor and outdoor is the most important factor affecting the heat transfer performance of the regenerative heat exchanger.With the increase of the indoor and outdoor temperature difference,the heat recovery efficiency and the heat transfer rate of the heat accumulator have a great increase.In the temperature range of 3?-7?,the heat recovery efficiency increases by an average of 7.2% for every 1? increase in temperature,and the average heat storage rate increases by 17%.