Numerical Test Research On The Law Of Mine Ventilation Roadway Heat Exchange

Mine ventilation system is an important part of mining. Ventilation can adjust underground climate and ensure underground employees life safety. In the process of underground ventilation, the phenomenon of heat and moisture exchange between airflow and underground heat source will continue to occur, which will lead to the air temperature rise. Higher temperature air is an unsafe factors, it will do harm to the physical and mental health of underground staff. Therefore, to study the various factors that affect the size of the underground thermal environment and discuss airflow heat and moisture exchange law is of great significance for safe production of coal mine and underground thermal environment control.On the collection and access to domestic and foreign literature, systematic analysis of the mine ventilation heat exchange theory was given. A numerical simulation test using fluent solver was set up to study the process of heat-moisture exchange based on the experimental design method. Then the test data were analyzed, and discussed the interaction of various factors in the process of the exchange of heat and moisture. Finally the thermodynamic model of the underground thermal environment was determined.The main research content and conclusions are as follows:(1)The course of study of domestic and foreign mine of heat injury governance and ventilation heat and moisture exchange was introduced and the mine heat source and its mechanism of action was also summed up. Combined with the knowledge of heat transfer and engineering thermal physics, ventilation heat and moisture exchange theory and airflow flow principle were elaborated, and provided theoretical support for the numerical simulation.(2)The course of development of FLUENT solver and its function were introduced. FLUENT software simulation based control equation and its mechanism were given. The type of the the FLUENT simulation process boundary and initial conditions were pointed out and provided the basis for the tests carried out. (3)10factors that affect heat-moisture exchange between tunnel wall and airflow were chosen in the orthogonal test while the temperature and relative humidity were selectd as the target factor. With the method of analysis of variance to analyse the test data, the influence factors were screened. The results showed that3factors had a greater impact on endpoint temperature, all of which showed a positive correlation. Besides, tunnel wall humidity was the most obvious factor affected the endpoint humidity and there was a positive correlation between them, while the influence of the remaining factors was small.(4)After factor screening, factors affecting the endpoint temperature contains tunnel wall temperature, length, inlet air temperature, wind speed and air intake humidity; factors affecting tunnel endpoint relative humidity include the wall humidity, inlet air temperature, wind speed, air humidity, and the tunnel wall temperature. Single factor experiments were set up with respectively two trials while temperature and relative humidity were selected as the target factors. After the analysis of each set of test data, single factor formulas were determined, and various factors on the mechanism of action of the target factor were discussed.(5) After the analysis of surrounding rock heat transfer and heat-adjust ing layer theory, heat-adjusting layer radius, protolith temperature and thermal conductivity were choosen in the orthogonal experiment while the wall temperature was select as target factor. The test results show that the factors affect wall temperature follow the order of protolith temperature, thermal conductivity, heat-adjusting layer radius. Using SPSS software to analyze the experimental data, then got the wall temperature formula.(6) BBD response surface experiments were set up while temperature and relative humidity were selected as the target factors. The test results show that the factors have second-order interaction. The interaction factor response surface maps, contour maps and response surface model were obtained after the analysis of the experimental data.(7)Consolidated all test data in the text, using SPSS software to get the ventilation heat exchange process thermodynamic model equation, respectively: T=p0+p1Tb+p2Lp3+p4Tj+p51nV+P6φj2+P7φj+P8TbL+P9TbTj+P10TbV+P11Tbφj+P12LTj+P13LV+P14Lφj+P15TjV+P16Tjφj+P17Vφj φ=q0+q1φb+q21nTf+q31nV+q4φj+q5Tb2+q6Tb+q7φbTj+q8φbV+q9φbφj+q10φbTb+q11TjV+q12Tjφj+q13TjTb+q14Vφj+q15VTb+q16φTb(8)Numerical simulation calculation and model formula were used to check an actual project based on the measured data and discussed the model accuracy.