Intelligent control of gas drainage main pipelines based on LSTM prediction and pump-valve coordination

This study aims to address delayed tracking of pure gas extraction flow and mismatched control targets caused by strong nonlinear coupling between drainage pumps and motorized valves and sharp fluctuations in gas emission in coal mine gas drainage main pipelines. An intelligent pump-valve coordinated control strategy following a valve-first, pump-second principle was developed, and an intelligent control system for gas drainage main pipelines based on Long Short-Term Memory (LSTM) prediction and pump-valve coordination was designed. To optimize pure gas extraction flow, the LSTM model predicted future pure gas extraction flow using pure gas extraction flow, valve opening, pump frequency, and drainage negative pressure as inputs. The predictions were subjected to reliability checks. When the predictions passed these checks, the trend in pure gas extraction flow was determined from the relationship between predicted and measured values. When the predictions failed the checks or feedforward adjustment could not meet the control requirements, the system switched to a feedback correction mode based on real-time deviations. A dynamic target update mechanism triggered by the failure of successive adjustments was designed, achieving a dynamic match between control targets and changing operating conditions. Experimental results showed that the maximum dynamic deviation under intelligent pump-valve coordinated control was ±6.2 m³/min, representing reductions of 66.5% and 50.8% compared with manual experience-based control and conventional Proportional-Integral-Derivative (PID) control, respectively. The mean absolute percentage error was 6.8%, representing reductions of 63% and 45%, respectively. Intelligent pump-valve coordinated control achieved the shortest response time and the fewest overshoots, with significantly fewer pump frequency adjustments than PID control, confirming the effectiveness of the valve-first, pump-second strategy. Field application results showed no obvious oscillations or high-frequency adjustments during operation. The intelligent control system can effectively improve the ability to dynamically maintain pure gas extraction flow in drainage pump station main pipelines, with good control stability and adaptability to field conditions.