The Study Of Flow Field Analysis And Structural Optimization Of Heat Pipe Heat Exchanger Air Duct In Mine Return Air Source

Mine return air is a kind of high-quality waste heat recovery energy.The heat pipe heat exchanger system can technically realize the use of this high-quality low-temperature heat source,and the quality of the flow field in the heat exchange duct of the mine return air source heat pipe heat exchanger system directly affects the heat exchange effect and the ventilation resistance of the mine.After the system is in actual operation,the flow field inside the flow channel of the heat pipe heat exchanger is uneven and the pressure drop in the air duct is large.The state of the flow field of the fan air flow is complicated,and the processing air volume of each module is greatly different.This paper analyzes and optimizes the distribution law of the flow field in the heat exchange duct of the mine return air source heat pipe heat exchanger using a combination of theoretical analysis,on-site experimental testing and numerical simulation.First of all,field experiments were conducted on the flow field in the duct of the mine return air waste heat recovery system in the actual project.After analysis,it is found that the cross-section wind speed of the heat pipe module in the air duct is greatly different,and the air volume processed by each module is very uneven.At the same time,the excessive local wind speed will also increase the resistance of the module.By changing the different operating conditions of the fan,it is concluded that the fan has a diversion effect,but the effect is small.Secondly,Fluent software was used to simulate the return air duct of the mine return air waste heat recovery system,and the influence of different inlet speeds and different fan opening conditions on the flow field in the air duct was analyzed.The results show that the greater the inlet velocity,the greater the pressure difference between the inlet and outlet of the duct,and the more obvious the pressure drop.The maximum unevenness rate and comprehensive unevenness amplitude of the module remain basically unchanged with the change of inlet speed.Without changing other parameters,the fan in the front section of the module has a better guiding effect on the flow field of the duct,while the fan in the rear section has a smaller effect.Finally,the flow field in the air duct with different deflectors,different opening methods,different inlet angles and different distances between the fan and the module was optimized.The results show that on the basis of the original working conditions,the flow field in the ventilation duct is improved after the deflector is installed,and the total pressure drop of the system,the maximum unevenness rate of the module and the comprehensive unevenness amplitude are all reduced.When the opening method is the left exit and the entrance angle is parallel to the hypotenuse of the return air front room,the basic parameters of the flow field in the air duct meet the expected requirements.At the same time,when the distance between the module and the fan is about 2m,the local flow field is optimal.This paper proposes an optimal layout method for the heat exchange air duct of the mine return air source heat pipe heat exchanger,which provides guidance for the subsequent engineering application design.