MINIMUM FLOW UNIT-BASED METHOD FOR CALCULATING NITROGEN CHARGING PRESSURE LOSS OF GOAF

摘要

Disclosed is a minimum flow unit-based method for calculating a nitrogen charging pressure loss of a goaf. The method comprises the following steps: (1) establishing a minimum flow model of a goaf, and determining a minimum flow unit of the minimum flow model; (2) taking the minimum flow unit as a study object, dividing a flow process into four different stages according to different relational expressions of a cross-sectional area changing along with a flow distance, and determining an overflow cross-sectional area expression of each stage; and (3) determining, according to the Navier-Stocks equation, the pressure loss value of nitrogen when flowing in the minimum flow unit. By means of the calculation method, the pressure loss of nitrogen in the flow process can be rapidly calculated, thereby providing theoretical support for the initial pressure needed by the nitrogen when nitrogen is injected; moreover, a charging range can be accurately calculated, and the calculation process can be simple and convenient.