Control method of heater used in automatic thermal cleaning process of extractor hood

Abstract

The invention discloses a control method of a heater used in an automatic thermal cleaning process of an extractor hood. The method is regulating work time of a water pump in each period, which is used for changing a resistance value of a PTC heater material to control heating power of a PTC heater. Power of PTC heating is detected through detection of current used when the PTC heater works, waterpumping volume can be changed through changing water pumping time of the water pump in each period according to the change of power, and by changing the water pumping volume, temperature of the PTC heater material can be in smaller fluctuation, thus, the resistance value of the PTC heater is guaranteed to be in a stable state, and heating power of the PTC heater is kept stable.

Description

technical field [0001] The invention relates to the technical field of range hood cleaning, in particular to a control method for a heater used in the automatic thermal cleaning process of a range hood. Background technique [0002] At present, some range hoods on the market have an automatic cleaning function. The cleaning function can be divided into two types according to whether it has a heating component. One is a cold cleaning function, that is, cleaning without a heating device; the other is a hot cleaning function. , this function has a heating device, such as some models on the market with steam washing, steam washing and other cleaning functions. There are mainly two kinds of heating devices with this cleaning function, namely resistive load heater and PTC (Positive Temperature Coefficient: positive temperature coefficient) heater, when a fixed voltage (such as mains 220 volts) is loaded on both ends of the resistive load heater, since the resistance value of the r...

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Problems solved by technology

[0003] Therefore, when a resistive load heater is used, the heating power can be controlled more conveniently, making it easier to control the steam volume or hot water temperature during the cleaning process under a constant heating power; when a PTC heater is used, the PTC heating power It changes with the temperature of the PTC material, and the structure of the PTC heater is generally fixed on one side of the PTC heating body with a heat sink for heat dissipation, and the heat sink is thicker so that the PTC can quickly achieve thermal balance and power stability. The temperature of the PTC heater is generally installed with a temperature measuring probe on the outside of the heat sink or an armored temperature measuring probe is opened on the heat sink. These temperature measurement methods cannot directly measure the temperature of the PTC heating body. The difference between the temperature and the actual temperature of the PTC heating material is large and lags behind, so it is difficult to accurately control the heating power of the PTC heater by detecting the temperature