Principle Of Gas Water Heater Water-Gas Linkage Device

Working principle of gas water heater water and gas linkage device

The function of the water-gas linkage device is to ensure that the gas control valve can be opened only when the water pressure is sufficient and is introduced into the heat exchanger to flow; and when the water flow stops or the pressure is insufficient, the gas supply passage of the gas is automatically cut off to prevent water shortage. Burning out the equipment is commonly referred to as "water arrives, gas arrives".

The working principle is simply that when sufficient shock water pressure is detected, the gas mechanical switch (straw hat pad) is activated, the circuit (usually a micro switch) is activated, and the motor, pulse igniter and solenoid valve are activated.

There are two main types of water-air linkages commonly used now: one is pressure type, and the other is differential pressure type.

1. Differential pressure type: It adopts the principle of the pressure difference of the water on both sides of the membrane, and its water pipe is provided with an orifice. When the water flows through the orifice, a pressure difference is generated on both sides of the membrane, which is opened and closed by the pressure difference. Gas disc. Since the inner diameter of the orifice is fixed, the more water that flows through the orifice per unit time, the faster the water flow rate when passing through the orifice. According to Bernoulli's principle, the water produced on both sides of the orifice The greater the pressure difference, the valve disc is controlled by the valve stem, so that the degree of opening of the valve port is also increased. It is ensured that the temperature of the gas water heater remains basically stable within the heat load range of the water heater, and it will not be cold and hot. When the water valve is closed and the water stops flowing, the pressure difference on both sides of the membrane disappears, the valve flap is reset under the action of the spring, the air supply to the main burner is cut off, and the main burner is extinguished (if there is a small fire burner at this time, the keep the original burning state). The differential pressure water-air linkage valve can be used for both the front system and the rear system. The water-gas linkage valve is an important part connecting the water and gas paths. In addition to using materials with good performance as the water barrier film, the water and gas paths should be strictly separated from the structure, so that even if the water barrier film is damaged, the water will not enter the gas pipeline. .

2. Reed switch (or Hall) type: the use of magnetic steel induction reed switch (Hall switch). Magnetic steel is installed in the water inlet pipe of the water heater. When the water flow of the water valve reaches the design value, the magnetic steel turns over the induction point, the reed switch is closed, the control circuit is connected, the gas valve is opened, and the water heater burns.