Control system for constant current output of gas water heater fan

Abstract

The invention provides a control system for the constant current output of a gas water heater fan. The control system comprises a current setting module, a fan running driving module, a current feedback reading module, a current comparing module and a current regulating module, wherein the current setting module determines the current setting value of the fan; the fan running driving module transmits the current setting value to the fan; the current feedback reading module reads the current output value of the fan at the moment; the current comparing module compares the read current output value with the current setting value and determines a current difference; and the current regulating module converts the current difference into a PWM value and transmits the PWM value to the current setting module. Actual output current is consistent with set current, and the output power of the fan is kept unvaried, so that actual air output quantity also can be kept in a set range when the external environment changes, and the combustion effect cannot be affected by the external environment factor.

Description

technical field [0001] The invention relates to the field of gas water heaters, in particular to a control system for constant current output of fans of gas water heaters. Background technique [0002] At present, there are two types of fans for gas water heaters on the market. One is an AC fan, which delays the output of the fan by detecting the zero point of the AC waveform of the mains to achieve speed adjustment control, or does not perform adjustment control; the other is a DC fan. , by adjusting the output voltage to control the fan speed; in the control process, the above two are adjusted with the speed as the reference, and the gas output is used as the adjustment reference when the fan is running, and the fan speed is set correspondingly according to the proportional relationship. This method is relatively simple and easy to control, but when the external environment changes, it is easy to cause changes in the exhaust air. For example, when the flue is slightly bloc...

AI Technical Summary

Problems solved by technology

This method is relatively simple and easy to control, but when the external environment changes, it is easy to cause changes in the exhaust air. For example, when the flue is slightly blocked, the exhaust air volume decreases and the resistance of the fan blades will also decrease. At this time, the fan speed will increase. In this way, under the condition of constant fan speed, the proportional relationship between gas and air in the combustion chamber will be out of balance, so that the combustion efficiency will be reduced, and the exhaust gas will exceed the standard.

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