Method and system for adjusting secondary pressure of fuel gas

Abstract

The invention discloses a method for adjusting secondary pressure of fuel gas. The method comprises the following steps that when it is detected that the secondary pressure of the fuel gas deviates from a preset secondary pressure range, the rotating speed of a fan is adjusted according to the secondary pressure of the fuel gas; the following steps are carried out repeatedly until the water outlettemperature meets a preset temperature range or the proportional valve current reaches a preset proportional valve current limit value; when it is detected that the water outlet temperature does notmeet the preset temperature range, whether the proportional valve current is within a preset proportional valve current range or not is judged; when the proportional valve current is not in the presetproportional valve current range, the proportional valve current is adjusted according to the difference value between the water outlet temperature and the preset temperature range; and when it is detected that the current rotating speed of the fan is not matched with the current secondary pressure of the fuel gas, the current rotating speed of the fan is adjusted according to the current secondary pressure of the fuel gas. The invention further provides a system for adjusting the secondary pressure of the fuel gas. According to the method and system for adjusting the secondary pressure of the fuel gas, it is ensured that the secondary pressure of the fuel gas is always matched with the optimal rotating speed of the fan when a whole machine runs at whatever air pressure.

Description

technical field [0001] The invention relates to the field of gas appliances, in particular to a method and system for adjusting the secondary pressure of gas, which are suitable for gas appliances such as gas heating water heaters, gas water heaters, and fully premixed gas stoves. Background technique [0002] A gas-fired heating water heater refers to a gas appliance that uses gas as a fuel to transfer heat to cold water flowing through a heat exchanger through combustion and heating to achieve the purpose of preparing hot water. The parameters of the existing gas-fired water heaters are based on laboratory test data or calculations to obtain the maximum gas consumption value and the minimum gas consumption value of the gas-fired water heater. The gas proportional valve opening and the corresponding current value are determined through testing. There are fluctuations in the coil resistance and the output current of the main board, resulting in abnormal fluctuations in the o...

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Problems solved by technology

[0004] In the process of realizing the present invention, the inventor found the following problems in the prior art: when the (external) gas pressure provided by the municipal gas pipeline network deviates from the standard value, the supplied gas pressure is unstable, and the proportional valve current and the gas error are prone to occur. The secondary pressure does not match. If it is detected that the preset gas secondary pressure range has shifted, simply increasing or decreasing the proportional valve current will make the gas secondary pressure unable to match the optimal fan speed, resulting in air The proportion of gas and gas is out of balance, which will affect the flue gas emission and reduce the thermal efficiency of flue gas emission

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