METHODS FOR MICROCLIMATE NORMALIZATION IN DEEP LONG BLIND DRIFTS

Abstract

The relevance of the research is provided by the complexity of microclimate normalization in long blind drifts which are driven deeply through geothermally heated rocks. The aim of the research is the evaluation of usability of different ways for microclimate normalization in the working section of the exploration drift-2 in the mine of PJSC «MMC "Norilsk Nickel"». Objects: the exploration mine drift exploration drift-2 of PJSC «MMC "Norilsk Nickel"». Methods: the numerical simulation of heat and mass transfer in the atmosphere of the long exploration drift, the comparative analysis of simulation results. Results. The paper reviews ways, comparing their features, advantages, and disadvantages, for microclimate normalization in deep blind drifts. The presented mathematical model describes the heat and mass transfer in the working section of the blind drift with ventilation through the air duct. The model considers convective and radiant heat transfers. The results of the numerical simulation are given for different air-cooling methods which are applicable in the case of the deep copper-nickel mine of PJSC «MMC "Norilsk Nickel"». Drawing on this, different mining and thermal engineering operations for normalization of air temperatures in the working section regarding safety requirements are compared. It is defined that increasing the intake air flowrate could not decrease the air temperature near the face. The use of thermally insulated duct significantly decreases the air temperature in the working section but does not reduce it to the permitted value. It is shown, that the air irrigation could normalize temperatures in winter and not during the summer months. Underground air conditioning is the most universal and effective way for this purpose but highly expensive.

Keywords

• blind drifts
• deep mine
• microclimate
• air irrigation
• thermal insulation
• air conditioning
• air duct