Effect of balance chamber on rapid pressure regulation ability of outflow valve

Under aircraft cabin inflow impact, the inadequate dynamic regulation speed of the pneumatic cabin pressure control system (PCPCS) may lead to a cabin pressure spike, causing “barotrauma”. Therefore, the working principle of the PCPCS was analyzed, and it was pointed out that the balance chamber may hinder the rapid movement of the outflow valve. A dynamic model of the PCPCS was established. The working states of the control chamber (A chamber) and the balance chamber (B chamber) in the outflow valve were described. The dynamic simulation of the PCPCS under cabin inflow impact was carried out. The dynamic working characteristics of the outflow valve and the force changes of the poppet were quantitatively displayed. The effects of the metering hole diameter of the balance chamber, the top diameter of the balance chamber, and the diameter of the balance diaphragm on the outflow valve’s response to cabin inflow impact were discussed. The simulation results show that appropriately increasing the metering hole size of the balance chamber can help to improve the response speed of the valve; the top diameter of the balance chamber has no significant effect on the movement speed of the outflow valve, and reducing the area of the balance diaphragm improves the response speed of the outflow valve significantly.