| In the process of mining coal resources,while consuming a large amount of energy,it will also produce usable waste heat resources,such as mine exhaust waste heat,mine drainage waste heat,air compressor waste heat,etc.The development and use of these clean energy sources accompanying the production process for mine production and living needs such as heating,bathing,shaft antifreeze,etc.can effectively reduce the use of coal and bring good economic benefits to the enterprise,while This is also in line with China’s development requirements to improve energy utilisation as proposed in the 14 th Five-Year Plan,and contributes to the achievement of the dual carbon targets by 2030 and2060.This thesis presents a case study on the application of heat pump technology to the recovery and reuse of waste heat from coal mine spent air and mine drainage waste heat resources for heating and antifreeze at the mine site,taking the Magyogou coal mine waste heat utilisation heating project as the subject.The overall design of the system was carried out by compiling and analysing the heating load of the mine heat users through field visits,comparative analysis and literature review,combined with the calculation of the load available from the waste heat resources in the mine,and finally determined a system for heating the mine with three heat sources: mine exhaust heat source,mine drainage heat source and electric heating auxiliary heat source.Based on the results of the load calculations and field research at the Magyogou coal mine,the main equipment and ancillary facilities such as the mine exhaust air source heat pump,mine drainage water source heat pump and electric heating boiler were selected and calculated.During the operation of the heating system,two tests were conducted on the indoor and outdoor temperatures and the operation of the units.According to the test results,it can be seen that the change in outdoor temperature has a small impact on the indoor heating temperature,the temperature of the spent air source and the temperature of the drainage source,while the impact on the heating capacity of the units is negatively correlated,and the higher the outdoor temperature is,the less heat is used and the heating capacity will be relatively lower.The analysis of the performance coefficients of each heat source unit shows that the heat production performance of the water source heat pump is higher than that of the spent air source heat pump unit,while the performance coefficient of the heat pump unit is much higher than that of the electric heat boiler.Combined with the test results of the water source heat pump,the analysis concluded that the stability of the heat source is an important indicator affecting the performance of the unit.When selecting waste heat utilisation technology,the water source heat pump system is preferred according to the mine’s own situation.The coal-fired boiler used for heating in 2019 emits a large amount of pollutants into the atmosphere during the heating season,but the application of the waste heat utilisation system for heating in 2020 will reduce carbon dioxide by approximately 2.6t,sulphur dioxide by approximately 24 kg,nitrogen oxides by approximately 7kg,ash by 260 kg and soot by 200 kg per year.Compared with the operation cost of the heating system of coalfired boilers in 2019,the operation cost of the heating season can be saved by RMB 6.42 million.The total investment of the waste heat utilisation project of the Magyogou coal mine is RMB22.02 million,and the static investment payback period of the project is 3.48 years,which is a short payback period.The obvious economic and environmental benefits will serve as a good demonstration for other coal mining industries in the promotion and application of mine waste heat utilisation technology. |
PDF Full Text Request