JPS5835320A - Combustion controlling device - Google Patents

Abstract

PURPOSE:To stably control the minimum flow rate of fuel for combustion such as combustion gas, by connecting an electrical governor of the secondary pressure variable type to proportionally control input, with a governor to control the minimum flow rate of fuel for combustion, and by juxtaposing both governors in a flow path for gas, on the input side of a main nozzle. CONSTITUTION:A combustion apparatus is composed so as to feed to burn combustion gas into a main burner 7 through a main nozzle 6. An electrical governor 3 of the secondary pressure variable type to control input command is provided to a flow path for gas on the gas feeding side of a main nozzle 6, and a bypass circuit 5, equipped with a governor 4 to control the minimum flow rate of combustion fuel, is provided to the governor 3 as a bypass for it. When the primary solenoid-operated valve 1 is opened, combustion gas is fed into a pilot burner 9, passing through a pilot tube 8, and is ignited. Then, when the secondary solenoid-operated valve 2 is opened, the combustion gas is simultaneously fed into both governors 3 and 4, so that the combustion gas is slowly ignited by the pilot burner 9 upon the main burner 7, if the governor 3, for instance, is controlled according to the circumstances.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion control device that can stably control the minimum combustion flow rate of combustion gas, etc., provided in the middle of a flow path such as a gas flow path.

Conventionally, in gas combustion appliances incorporating proportional control valves, etc., the means to control the minimum combustion flow rate is to control the valve body by changing the current value given to the electromagnetic coil, and the valve body is used to control the valve body through the hole in the valve seat. The degree of opening was controlled.

If the minimum combustion flow rate is controlled by such a means, the opening degree of the hole in the valve seat will be adjusted very minutely, resulting in variations in the minimum combustion flow rate control. Therefore, in order to absorb the variation between the There was a problem that the width or the ratio thereof (hereinafter referred to as T, D, R) could not be made large.

In addition, the minimum combustion flow rate is controlled by a fixed small hole nozzle,
For proportional control valves that control the valve body using the current value applied to the electromagnetic coil only in the proportional control region, when changing the gas type, it is necessary to replace or adjust the valve seat or small hole nozzle of a size corresponding to the gas type. There was a strange problem.

The present invention has been made in view of the above points.

The above conventional drawbacks are solved by connecting an electric secondary pressure variable governor for proportional input control and a governor for minimum combustion flow rate control in parallel to the input side gas flow path of the main nozzle. .

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, 1 is a first solenoid valve, 2 is a second solenoid valve, and 3 is a first solenoid valve.
is an electric secondary pressure variable governor for input proportional control connected to the gas outlet side of the second solenoid valve 2;

4 is a governor for controlling the minimum combustion flow rate, which is also branched from the second solenoid valve 2 by a bypass circuit 6. and,
The electric secondary pressure variable governor 3 and the governor 4 are reconnected at the outlet side by their respective forces and guided to the main nozzle 6. Further, a main burner 7 is arranged at the tip of the ejection port of the main nozzle 6.

An intermediate pilot burner 9 is provided at one end of the main burner 7 and is branched from the middle between the first solenoid valve 1 and the second solenoid valve 2 and led to a pilot pipe 8 .

In the above configuration, first, when the first solenoid valve 1 is opened, combustion gas flows through the pilot pipe 8 to the pilot burner 9, and at the same time, the pilot burner 9 is ignited by a piezoelectric ignition mechanism (not shown) or the like. Subsequently, when the second electromagnetic valve 2 is opened, the combustion gas that has passed through it flows into the electric secondary pressure variable governor 3 and the governor 4 at the same time. However, if the current value given to the electromagnetic coil of the electric variable secondary pressure governor 3 is controlled so that the total flow rate of the combustion gas flowing at this time is, for example, one-half of the maximum combustion flow rate, then the combustion gas will be ejected from the main nozzle. The combustion gas generated is slowly ignited in the main burner 7 by the flame of the pilot burner 9.

Furthermore, in the case of a gas instant water heater as a combustion appliance, for example, the electric secondary pressure variable governor 3 is electrically controlled to reach the set temperature, and combustion gas corresponding to the set temperature is ejected from the main burner 6. . Further, FIG. 2 is a diagram showing general control characteristics in a combustion appliance incorporating the electric variable secondary pressure governor 3. The horizontal axis shows the current value i given to the electromagnetic coil of the electric secondary pressure variable governor 3, and the vertical axis shows the combustion gas control flow rate Q. Me is the minimum combustion flow rate value controlled by the minimum combustion flow rate control governor 4;
is the maximum combustion flow rate value controlled by the electric secondary pressure variable governor 3 for input proportional control.

Furthermore, the diagrams a, b, and a conceptually show variations in the control characteristics of the electric variable secondary pressure governor 3. If the minimum control current value at the point where this diagram intersects with the line d of the maximum combustion flow rate value Q=Me is 11 and the maximum control current value corresponding to the maximum combustion flow rate value J12 is 12, then %11 to 12
The electric secondary pressure variable governor 3 is proportionally controlled by the control current, and correspondingly, the combustion flow rate is proportionally controlled from Jh to Me.

In addition, at a current of 11 or less, the minimum combustion flow rate is set by governor 4.
is controlled so that it is always constant.

When the value 10 becomes smaller than 11, the second solenoid valve 2
is configured to perform ON-OFF control.

As is clear from the above explanation, what controls the minimum combustion flow rate value is the governor 4 itself, which always controls the outlet pressure to be constant even if the combustion gas supply pressure fluctuates. When moving from the proportional control region A to the 0N-OFF control region as shown in FIG.

In addition to the embodiments described above, when changing the gas type, the minimum combustion flow rate value q1 can be set by simply changing the spring pressure of the governor 4 in a stepwise manner in accordance with the gas type.

Furthermore, it is possible to absorb variations in control characteristics caused by manufacturing or adjustment errors of the proportional control valve, that is, the electric secondary pressure variable governor. Therefore, the effect of lowering production costs can also be obtained.

[Brief explanation of drawings]

1) is a system diagram showing one embodiment of the combustion control device of the present invention, and FIG. 2 is a diagram illustrating control characteristics of the combustion control device. 3...Electric secondary pressure variable governor for input proportional control, 4...Governor for medium/minimum combustion flow rate control, 6...Bypass circuit, 6-...9II main nozzle, 7...・・・
・Main burner. Name of agent: Patent attorney Toshio Nakao and one other persontJ
Ii1 figure

Claims (1)

[Scope of Claims] 0) A combustion device is configured that supplies combustion gas to a main burner through a main nozzle to cause combustion. An electric secondary pressure variable governor for input proportional control is provided in the gas flow path on the gas supply side from the main nozzle, and
Side I of this electric secondary pressure variable governor for input proportional control
℃, a combustion control device equipped with a bypass circuit with a governor for controlling the minimum combustion flow rate. (2) The combustion control device according to claim 1, wherein the governor for controlling the minimum combustion flow rate is an electric secondary pressure variable governor.