GAS FURNACE CONTROL METHOD AND CONTROL SYSTEM, AND GAS FURNACE

摘要

Provided are a gas furnace control method and control system (200), and a gas furnace. The gas furnace control method comprises: measuring the actual pressure at an outlet of an exhaust pipe; obtaining a length pressure loss of the exhaust pipe and a pressure drop of an exhaust fan; according to the normal input load of a gas valve, the actual pressure of the exhaust pipe outlet, the length pressure loss of the exhaust pipe, and the pressure drop of the exhaust fan, the actual input load of the gas valve is obtained; according to the actual input load of the gas valve, adjusting the extent of opening of the gas valve. The gas furnace control system (200) comprises: a measurement module (210), used for measuring the actual pressure at the outlet of the exhaust pipe; a control module (305), used for obtaining the actual input load of the gas valve according to the normal input load of a gas valve, the actual pressure of the exhaust pipe outlet, the length pressure loss of the exhaust pipe, and the pressure drop of the exhaust fan, and adjusting the extent of opening of the gas valve according to the actual input load of the gas valve. The gas furnace control method is capable, when the air volume of the exhaust fan decreases and it is unable to meet high-capacity gas burning requirements, of ensuring, according to the actual input load of the gas valve and the gas valve automatically reducing the amount of gas input, that the combustion of oxygen is sufficient and that the fuel burns completely, thereby achieving high heating capacity and high energy efficiency under normal conditions, while in extreme environments, harmful gases can be effectively suppressed, guaranteeing the objective of safety.