Double constraint optimization method for correcting air resistance in simulating mine ventilation system in operation

Aiming at the problem that the air resistance needs to be adjusted manually and repeatedly when the network solution method is used to simulate a mine ventilation system in operation, and the consistency between the simulation results and the measured results is not high, a double constraint optimization model for correcting air resistance was established. The optimization model takes the measured air volume and primary air resistance as the original data, takes the minimum correction to the primary air resistance as the objective function, takes the loop air pressure balance equation and node flow balance equation as the equality constraints, and takes the upper and lower bounds of roadway air resistance as the inequality constraints. The Lagrange multiplier method is used to solve the optimal solution of air resistance modification under equality constraints, and then the iterative method is used to obtain the final solution under inequality constraints. The corresponding software was developed. The example application shows that the iterative solution process for inequality constraints obtained the convergence result after 12 iterations in the application example. The air resistance corrected by this model can make the air volume and fan air pressure calculated by the network completely consistent with the measured values. It is possible to obtain minimal or even negative unintentional air resistance only by considering the optimization model under equality constraints and the double constraint model considering the wind resistance limit can limit the air resistance to a reasonable range. The developed software applies the ventilation network solution and optimization method to simulate the mine ventilation system at the same time, which reduces the cumbersome operation of manual repeated adjustment of air resistance.