Study On Heat Transfer Performance Of Mine Water Heat Exchanger

In the process of coal mining and production,a large amount of mine wastewater will be discharged,which will not only cause environmental pollution,but also waste the heat energy in the mine wastewater.The temperature of mine water is stable all the year round,so it can be used as the low temperature heat source of water source heat pump.Compared with the boiler system in winter heating,the mine water source heat pump has no combustion process and will not affect the environment;At the same time,the mine waste water can be used for heating to turn waste into treasure,which has higher economic value.Because of the characteristics of mine water itself,it is easy to scale,block and corrode on the pipe wall when it is directly used.Therefore,in engineering practice,the mine drainage is generally in the form of indirect heat extraction,among which the most critical component is the intermediate heat exchanger.Therefore,this paper combined with the characteristics of mine drainage,the intermediate heat exchanger has been studied in theory,experiment,numerical simulation and other three aspects.The main research contents of this paper are as follows:(1)The relevant characteristics of mine drainage are introduced.The basic operation principle of heat pump is introduced,and the related research progress of heat pump is summarized.The research progress of heat exchanger in theory,experiment and simulation at home and abroad is analyzed.(2)Through the analysis of the direct and indirect system,the indirect system is selected as the heat pump system of this topic.On this basis,the selection design of the intermediate heat exchanger is carried out,and the heat transfer model of the immersive heat exchanger is deduced.(3)The experimental system of the immersive heat exchanger was built.Through experiments,the heat transfer characteristics of the immersive heat exchanger under different water temperature inside and outside the tube,flow rate inside and outside the tube and different water types were studied,and the experimental results were sorted out and analyzed.(4)Using COMSOL numerical simulation software,the heat transfer numerical model of the immersive heat exchanger is established.The temperature distribution and flow inside the heat exchanger are analyzed and studied,and the temperature distribution and velocity distribution inside the heat exchanger are obtained,which provides theoretical guidance for the optimization design of the heat exchanger.The numerical model of single tube heat exchanger is established,and the accuracy of the experimental results is verified by analyzing and comparing the simulation results with the experimental results.The study on the immersive mine water heat exchanger in this paper provides a theoretical basis and reference for the design of mine water heat exchanger in practical engineering.