JPS62158918A - Combustion control device - Google Patents

Abstract

PURPOSE:To improve safety by changing over a control range for a current through a proportional control valve according to the kind of gas and changing accordingly the increase ratio of the rotational speed of a fan motor. CONSTITUTION:When the kind of gas is changed, the value of an adjustment resistor 20 in a proportional control circuit is changed over by means of a gas kind changeover circuit 19 in a control circuit 14 to change the potential of a normal connection point and change the control range for the current through a coil of an electromagnetic proportional control valve 13. At the same time a changeover switch (not shown) in a blast control circuit 17 is changed over by a ratio change circuit 21 to change the potential of the normal connection point and increase the rotational speed increase ratio of a fan motor 6. With this constitution, an amount of air corresponding to gas supply amount is automatically set up and it is possible to prevent lift in the flame and explosive ignition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a combustion control device for a gas combustor that allows the same electromagnetic proportional valve to be used even when different types of gas are used.

(Prior Art) It is known that the rotation speed of the fan motor is changed depending on the magnitude of the current flowing through the proportional control valve. In this case, when a different type of gas is used, the The energizing current control range of the proportional control valve is changed according to the type of the proportional control valve, and the gas supply amount control range is changed, and the rotation of the damper interposed in the air supply amount is manually adjusted to adjust the gas supply amount. Generally speaking, the control range of the combustion amount of the burner does not change even if the type of gas changes by supplying an amount of air commensurate with the amount of air.

(Problems to be Solved by the Invention) According to the above-mentioned conventional device, changing the energizing current control range of the proportional control valve in response to changes in gas type is achieved by switching the switching knob provided on the front panel of the gas combustor. Anyone can easily do this by adjusting the damper, so it is rare for people to forget to adjust it. It is located in the deep part of the container, and you can adjust it (1
Since the burner has to be adjusted, it is often forgotten to adjust it. If the burner is forgotten, the flame of the burner may lift or the burner may explode and ignite, which is undesirable.

(Means for Solving the Problems) The present invention attempts to solve the problem by automatically changing the amount of air supplied when the type of gas changes. It is equipped with an electromagnetic proportional control valve interposed in a gas supply path to a burner, and a fan motor that supplies air to the burner, and the rotation speed of the fan motor is controlled by the current flowing through the proportional control valve. The number of rotations of the fan motor relative to the current flowing through the proportional control valve, such as a switching means that changes the control range of the current flowing through the proportional control valve depending on the type of gas, A control means for changing the rate of increase of is provided.

(Function) The present invention has the above configuration, and according to this, when different types of gases are used for the same electromagnetic proportional control valve, for example, as shown in FIG. When changing from calorie gas to low calorie gas such as 6C, 7C, 4C, etc., the switching means changes the energizing current control range of the proportional control valve, and the control means changes the energizing current of the proportional control valve and the rotation of the fan motor. The relationship with the number is automatically changed from C line to A line, so that the control range of the burner combustion amount does not change even if different types of gas are used.

(Example) Next, an example in which the present invention is applied to a gas water heater will be described based on the drawings.

In Figure 1, (1) has a ventilation hole (2) at the bottom,
A gas water heater main body including an exhaust pipe (3) at the top,
The main body (1) is equipped with a heat exchanger (4) in the middle and a surface combustion type burner (5) for heating the heat exchanger (4), and a direct current generator in the lower part that supplies combustion air to the burner (5). A combustion tube (8) is provided with a fan motor (6), a combustion tube (8) having an exhaust port (7) connected to the exhaust tube (3) is housed in the -F section, and the heat exchanger (
The black water sent from the water supply pipe (9) on the upstream side of 4) is heated in the heat exchanger (4), so that hot water can be obtained from the hot water outlet pipe a0 on the downstream side of the heat exchanger (4). At the same time, the combustion exhaust gas is discharged to the outside through the exhaust stack (3).

In the figure, 0v indicates a gas supply path connected to the burner (5),
An electromagnetic on-off valve az on the upstream side and an electromagnetic proportional control valve 0 on the downstream side were interposed in the gas supply path 0D.

The increase/decrease control of the amount of gas supplied to the burner (5) is performed by a proportional control circuit a9 having the same configuration as the conventional one in the control circuit (l@, as shown in Fig. 2, and in the hot water outlet pipe 01). The coil of the electromagnetic on-off valve 0 is energized or de-energized by a signal corresponding to the deviation between the actual temperature detected by the temperature sensing element Oe and the set temperature in the proportional control circuit a9 to open or close the valve. This is done by closing the valve and adjusting the degree of opening by changing the current flowing through the coil of the electromagnetic proportional control valve Q3 within a range of about 15 to 230 mA.

Further, the increase/decrease control of the air supply amount to the burner (5) is performed by the air volume control circuit (+71) in the control circuit (+41), and the air is sent from the proportional control circuit a9 to the coil of the electromagnetic proportional control valve a. Input the same current as the current, convert it into a voltage between approximately 13 to 37 V according to its magnitude, and apply the voltage to the fan motor (6) to increase the rotation speed in the range of approximately 500 to 5000 rpm+. Do this by changing it.

In FIG. 2, 0& indicates the feedback circuit of the fan motor (6).

In controlling the gas supply amount and air supply amount as described above,
When the type of gas supplied to the burner (5) is changed from LPG to 40, for example, as shown in Figure 3, the control circuit (+
The gas type switching circuit (+!!1) which is the switching means in 41 changes the value of the adjustment resistor ■ in the proportional control circuit a9, changes the potential of the reference connection point, and connects the coil of the electromagnetic proportional control valve a3. The control range of the flowing current is from 15 to 230 mA to 15
ffi! Change the changeover switch (not shown) in the control circuit (+71), change the potential of the reference connection point, increase the rate of increase in the rotation speed of the fan motor (6) with respect to the current flowing through the coil, and change the gas type. Also, the control range of the combustion amount of the burner (5) and the control range of the temperature of the lagoon supplied by the gas water heater were made to remain unchanged.

In the illustrated example, the upper limit of the voltage of the fan motor (6) is kept at 37 V so that the air supply m does not become excessive with respect to the gas supply amount.

In addition, the current flowing through the electromagnetic proportional control valve 0 and the fan motor (6
) When determining the relationship with the rotational speed, it is easy to make adjustments using low calorie gas as a reference.

(Effects of the Invention) As described above, the knife according to the present invention includes a switching means for changing the control range of the energizing current of the electromagnetic proportional control valve according to the type of gas, and a rotation of the fan motor in response to the energizing current of the proportional control valve. A control means for changing the rate of increase in the number of gases is provided so that an amount of air commensurate with the amount of gas supplied to the burner can be automatically supplied to the burner, and even if the type of gas changes, the amount of combustion of the burner can be controlled. Since the control range did not change,
When the type of gas changes, the opening degree of the air supply damper is manually adjusted accordingly, so that the control range of the combustion amount of the burner does not change. Therefore, there is no risk that the flame of the burner will lift due to insufficient air supply, or that the burner will explode and ignite due to excessive air supply.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing an example of the implementation of the present invention, Fig. 2 is a block diagram showing the main parts thereof, and Fig. 3 is the energizing current of the proportional control valve and the fan motor when changing the gas type. FIG.

Claims (1)

[Claims] an electromagnetic proportional control valve interposed in the gas supply path to the burner;
and a fan motor that supplies air to the burner, and the rotation speed of the fan motor is changed according to the magnitude of the current supplied to the proportional control valve, wherein the proportional control is performed according to the type of gas. A combustion control device comprising a switching means for changing the control range of the current flowing through the valve, and a control means for changing the rate of increase in the rotational speed of the fan motor with respect to the current flowing through the proportional control valve.