Application Of Gravity Split Heat Pipe In Mine Waste Heat Recovery

At present,the country advocates energy conservation and emission reduction.In order to ensure the sustainable development of the country,it is necessary to improve the utilization rate of waste heat resources.Compared with traditional heat exchangers,gravity split heat pipe has been widely used in various fields due to its long heat transfer distance,low investment and no external power.According to the investigation,the coal mine is rich in waste heat resources,such as waste heat of return air,waste heat of drainage,waste heat of air compressor,etc.Based on the gravity model split type heat pipe application in mine return air heat recovery as the research object,combining heat transfer theory and the actual engineering research,design,site performance test,the feasibility from theory aspect research,for the split type heat pipe application in mine return air heat recovery engineering provides the theoretical basis and practical guidance.Firstly,the basic signs and heat transfer theory of split type heat pipe are analyzed.Then,combined with the characteristics of high moisture content and large return air volume of mine,a set of gravity split type heat pipe air supply system is designed for recovery of waste heat of mine return air.And the application effect of the system in mine return air waste heat recovery was tested in the field.The test results show that:The filling rate of gravity split type heat pipe system plays a key role in heat transfer balance of heat pipe.The minimum filling rate required by the system needs to be calculated according to the geometric parameters of the system.In this thesis,the minimum filling rate of system 9 is 27.62%,and that of system 12 is 22.28%.The inlet air volume of the module increased by 356.16 m ~3/min before and after the return air crosswind balance fan was turned on.After the addition of the fresh air side wind resistance balance fan,the module inlet air volume increased by 1139.71 m~3/min,and the system air volume increased significantly,while the return air side fan had little influence on the system air volume.Finally,the economy and environmental protection of split type heat pipe system and gas-fired boiler system are compared.The results show that the annual operating cost of split type heat pipe system can save 5.7778 million yuan compared with gas-fired boiler system economically.At the same time,can greatly reduce the discharge of pollutants,environmental protection benefits.During the engineering test,the temperature difference between fresh air inlet and outlet was 11 ?,and the temperature difference between return air inlet and fresh air inlet was 20 ?.The heat exchange performance of heat pipe heat exchanger of split type heat pipe air supply system was good,which could meet the requirements of wellbore heating.The calculation method of minimum filling rate is suitable for the scheme design of this kind of system.Through the analysis of economy and environmental protection of the scheme,it is found that the split-type heat pipe air supply system,although the investment cost is large,but the operation cost is low,the static recovery period is short,and the economic and environmental protection benefits are high.To sum up,the gravity split heat pipe technology is worth popularizing in mine return air waste heat recovery.