JPS6014122Y2 - gas water heater - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to slow ignition that prevents ignition noise and ignition errors during ignition in a premix combustion type gas water heater with a constant air-fuel ratio.

Conventionally, in household gas water heaters, the gas valve was opened in conjunction with the water valve.

Therefore, in order to have a slow ignition function, the gas valve required a slow ignition mechanism.

Moreover, when igniting after passing water, the gas valve was already open, so slow ignition was not possible.

On the other hand, in water heaters using premixed gas burners,
If the amount of gas is reduced by slow ignition using a gas valve, there will be excess air and ignition will not be possible, so conventional slow ignition devices cannot be used.

The present invention solves the above problems, and examples thereof will be described below with reference to the accompanying drawings.

FIG. 1 is a diagram showing the principle of construction of the gas water heater of the present invention. In relation to its operation, a gas valve 1 includes a gas valve switch 2 and an ignition switch 3 that operate in conjunction with the shaft of the gas water heater.
The water valve 4 is provided with a flow switch 5 that operates when water is flowing.

As shown in Fig. 2, when the gas valve interlocking switch 2 and flow switch 5 operate, the rated voltage is applied to the fan motor 7, and when either or both are not operating, the set voltage (for example, 30 mm) is applied to the resistor 15. Both the switches 2 and 5 are connected in series so that the voltage is applied through the switch.

Further, the solenoid valve 6 is opened only when both switches 2 and 5 are operated.

Now, when the power source 5w14 is turned on, the set voltage is applied to the fan motor 7.

When the gas valve 1 is opened, the gas valve interlocking switch 2 is turned on, and at the same time, the pilot burner 8 is ignited by the ignition switch 3.

When hot water supply starts, the flow switch 5 is operated by the water valve 4, and the rated voltage (100V) is applied to the fan motor 7, and at the same time, the solenoid valve 6 is opened.

As shown in Fig. 3, the fan motor 7 is rated at pressure (10
When 0V) is applied, the rotational speed of the motor gradually increases due to inertia and reaches a steady rotational speed, but the amount of air blown also increases as the rotational speed increases.

On the other hand, on the gas side, a gas amount corresponding to the amount of air is supplied to the low pressure portion of the mixing tube 9 via a gas governor 10 to which the high pressure of the mixing tube 9 is fed back.

There, the air-fuel mixture sent to the burner 11 by the pilot burner 8 is ignited and combusted, but the amount of air-fuel mixture at the time of ignition gradually increases at a constant air-fuel ratio in accordance with the increase in air volume due to the inertia of the fan motor 7, so it is slow. Ignition is obtained.

It is also possible to control the hot water temperature by installing a thermistor 13 at the outlet of the heat exchanger 12 to detect the hot water temperature and controlling the amount of air blown.

Fig. 2 is a principle circuit diagram, in which a shows voltage switching by a resistor 15, b shows air blowing 8 high and 16 by motor tap switching,
This is an example of switching to weak 17.

It goes without saying that it is also possible to change the amount of air blown by phase control.

According to the present invention, when the burner 11 is ignited, the fan motor 7 rises above the set voltage and supplies gas to a constant air-fuel ratio as the air volume increases due to the inertia of the fan motor 7, so that slow ignition is achieved. Abnormal ignition noise 9 Ignition mistakes can be prevented.

This is because when the fan motor 7 rises above the voltage O, the air-fuel ratio may not be constant when the air volume is small, causing abnormal ignition noise and ignition errors.

In addition, only when the gas valve interlocking switch and the flow switch operate, the regular voltage is applied to the fan motor and the solenoid valve 6 is opened, which solves the problem of the conventional system where slow ignition does not occur when ignition occurs at the water flow ridge point. .

Furthermore, since it utilizes the rise in air volume due to inertia when starting the fan motor, there is no need for a slow ignition mechanism on the gas side, allowing slow ignition with just a switch.

[Brief explanation of drawings]

Figure 1 is a diagram of the principle of construction of the water heater of the present invention, Figure 2 a, b
is a principle circuit diagram, and FIG. 3 is a diagram showing the relationship between fan motor applied voltage, air volume, and gas volume. 1... Gas valve, 2... Gas valve switch, 5... Flow switch, 7... Fan motor.

Claims (1)

[Scope of utility model registration request] The present invention has means for varying the voltage applied to the fan motor by interlocking the gas valve interlocking switch and the flow switch, and means for supplying the amount of gas according to the amount of air to keep the air-fuel ratio constant. The means for varying the applied voltage includes applying a rated voltage to the fan motor only when the gas valve interlocking switch and the flow switch are interlocking, and applying a set voltage lower than the rated voltage when the gas valve interlocking switch and the flow switch are not interlocking or when neither of them operates. When the power switch is activated, the set voltage is applied to the fan motor, when the gas valve interlocking switch is activated, the pilot burner is ignited, and when the gas valve interlocking switch and the flow switch are activated, the solenoid valve for supplying gas is opened. This gas water heater allows slow ignition when the fan air volume is in a transition between the set voltage air volume during steady state and the applied voltage air volume during steady state.