Research And Application Of Return Air Heat Exchange System In Ciyaogou Mine

As an important mine secondary product,mine return air contains abundant lowtemperature geothermal resources.Its effective development and utilization will provide a heat source for the production and life of the mining area,and it is of great significance for the realization of clean heat supply in the mining area.After continuous innovation,the utilization technology of mine return air waste heat has shown various forms,but each has certain limitations.Based on the return air waste heat utilization project of Shanxi Hequ Jinshen Ciyaogou Coal Industry Co.,Ltd.,this thesis conducts mine return air heat exchange system design,return air heat exchanger design,equipment research and development,and industrial experiment work to try to break through the drawbacks of existing technologies.First of all,starting from the actual needs of Ciyaogou coal mine,based on the analysis of the existing mine return air waste heat utilization technology,this thesis designs a new two-stage direct cooling mine return air heat exchange system suitable for the actual needs of Ciyaogou,Which improves the feasibility and security of the system by coupling low-temperature heat pump technology and heat pipe technology.Secondly,in order to meet the needs of the system,this thesis designs and develops a gas-liquid low-temperature heat pipe heat exchanger suitable for mine return air with low temperature,high humidity and high coal dust environment based on the design principle of heat pipe heat exchanger.It uses the isothermal property of the heat pipe to overcome the problem of easy freezing on the surface of conventional heat exchangers under the low temperature environment;realizes the coupling of heat pipe heat exchange technology and heat pump technology in the development and utilization of lowtemperature heat energy of mine return air,which can meet the requirements of various ends of the mining area.Heat demand.After the design of the equipment is completed,arc welding,brazing,secondary welding and other welding processes are used to process and manufacture the equipment,and the equipment is inspected by various testing methods such as "bubble method" and "isothermal experiment method".After the equipment research and development is completed,it will be applied to the Ciyaogou project site.Finally,field tests were conducted to test the actual operating effects of gas-liquid low-temperature heat pipe heat exchangers and heat exchange systems.Tests show that the single module of gas-liquid low-temperature heat pipe heat exchanger has a heat exchange rate of 63 k W,and the overall system heat exchange rate has reached 1937.6k W.The designed equipment and system can better extract the return air waste heat;the equipment is in operation during the entire operation period.No icing occurs,indicating that the equipment has a good antifreeze effect;the average flow resistance of the heat exchange equipment is 116.1Pa,which is lower than the design resistance,indicating that the selected fan can meet the actual operation requirements of the equipment.In summary,this article has verified the designed two-stage direct cooling mine return air heat exchange system and the developed gas-liquid low-temperature heat pipe heat exchanger from both theoretical and practical aspects through the Ciyaogou mine return air waste heat utilization project.The feasibility of application in mine return air heat exchange has made a new attempt for the development of mine return air waste heat utilization technology.