| Coal mine ventilation system is an important part of the mine production system, it should be designed reasonably and elaborately to ensure that the scope of incidents can be controled effectively.<<Coal Mine Safety Regulations>>provides that:production herisons and the mining area adopt district ventilation; mining, excavation face should adopt independent ventilation; and roadway must use full-pressure ventilation or local fan ventilation. This paper discusses about coal mine ventilation system, using the joint operation of multi-fan ventilation system theory and optimization theory, drawing on existing research outcomes, achieved the following results:1. This paper studys the optimization of mine ventilation based on the principle of minimum energy, using two different ways:the air flow pressure balance method and the node pressure method,for caculating the ventilation network.2. In this paper, the optimal choice of fan is analyzed in detail, during the joint operation of multiple fans, we view each fan as it operates seperately, and then select one by one, when picking up each fan's blowing rate and air pressure conditions, it must be calculated by the value from the natural distribution of the network winds, and not the man specified value. After the preselection, then caculate the distribution of network winds and the real working condition during the joint operation of multiple fans.3. This paper Established a mathematical model of the local fan ventilation system through the analysis of the way uesd in the local fan ventilation, found out the relational expression of f andβ,as well as f andδby regression analysis. Determined the method for caculating the blowing rate required by the driving face through analysis. In practice, the blowing rate is generally calculated according to the main work of the ventilation; in the roadway where has a large number of gas emission, it is caculated according to the factor of gas; in the smoke roadway with no gas emission, according to factors of gas and mineral dust.4. This paper analysed the way of joint operation by the main fan, concludes that the main fan parelled connection method is suitable for the situation where the pipe network's windage is small, but there's a lack of blowing rate due to the capacity shortage of the fan. When using axial fans in parallel, in addition to consider the effect of parallel connection, one also have to analyse the stability. This paper, for the first time, proposes an unusual way of joint operation-local fans work in series. Analysis pointed out that the blowing rate provided by the first stage local fan must be equal to or slightly larger than the blowing rate provided by the second stage local fan, specificly grows as the amount of the wind tunnel's air leakage increased. the execss wind is generated to offset the air leakage generated by the wind tunnel.5. Established a mathmatical moel for monitoring of joint operation of multi fans. In normal times and normal times, disaster monitoring system of non-mathematical model of the objective function and constraints are different. Through the establishment of monitoring system in real time changes in the system to adjust the system so that the optimal ventilation system is running. When the mine disaster warning appears (such as gas accumulation), the automatic monitoring system for system parameters can be adjusted from time to time, so that disasters can be avoided; when the mine disaster mutation occurs, the rapid control of a variety of ventilation equipment to minimize the hazards limits.6. This paper considered the actual situation of Luling Coal Mine engineering of Huaibei Coal Mining Group, according to the data generated by related computatioanl fomulas and with the mine ventilation system optimization theory, developed two different optimize programs and compared them with each other, choose the second as the best program, and analysed issues around the joint operation of multi-fan in technical level. |
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