JPS5815687B2 - Combustion control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion control device that maintains an appropriate ratio between combustion amount and combustion air amount.

Conventionally, a fuel pressure regulator has been generally used as a device for stabilizing the fuel supply pressure, but it does not have a control function related to the amount of combustion air.

There is also an idea to create a relationship between fuel and air by detecting the fuel supply pressure and electrically controlling the fan rotation speed, but this has the disadvantage of being expensive.

Furthermore, there is a method of using a zero governor to supply the combustion amount according to the amount of air, but this method is only applicable to all primary burners and high-order burners, and is difficult to apply to all secondary burners and low-order burners. .

Therefore, the main object of the present invention is to always maintain the excess air ratio at an ideal value by automatically adjusting the amount of fuel according to the amount of fuel air.

As a result, high efficiency and stable combustion can be ensured.

In addition, it is also possible to automatically cut off the fuel supply if air does not flow, so one of the purposes is to improve safety.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, the air passage first inflows from an air population 1, passes through an air orifice 2, and is then guided from an air outlet 3 to the combustion section.

4 is a first diaphragm installed in the air passage from the air population 1 to the air outlet 3, which divides the air chamber into a high air pressure chamber 5 and a low air pressure chamber 6, and is always attached to the high air pressure chamber 5 side by a spring 7. Forced.

8 is a connecting plate for transmitting the operation of this diaphragm 4 to the outside, and has an air passage 9 therein.

10 is a connecting rod that interlocks with the connecting plate 8, and constitutes a support point for the governor spring 17.

Next, the fuel path enters from the gas port 11, passes through the fuel valve hole 13 formed by the actuator 12 and the body 20, and is led from the gas outlet 14 to the nozzle in the combustion section.

A second diaphragm 15 separates the secondary gas pressure chamber 16 from the atmosphere, and is biased downward in the figure by a governor spring 17.

Reference numeral 18 denotes an actuator spring that urges the actuator 12 upward so that it always moves in unison with the second diaphragm.

Reference numeral 19 denotes a shutoff valve provided on the actuator 12 and faces the body 20.

Next, the operation will be explained.

Since an air pressure difference corresponding to the amount of air passing through the air orifice 2 is generated between the high air pressure chamber 5 and the low air pressure chamber 60, the first diaphragm 4 is moved downward by the spring T1 spring 17 and the actuator spring 1.
8 and is displaced to the balance position.

In this state, for example, when the gas pressure fluctuates, the second diaphragm 15 detects the fluctuating pressure and changes the position of the regulator,
It operates to keep the gas pressure in the gas secondary pressure chamber 16 almost constant.

This is the same as a general gas governor.

In this way, if the amount of air is constant, combustion can be performed at a constant gas/air ratio even if the gas pressure fluctuates.

Next, when the blower voltage increases or the intake/exhaust duct becomes shorter, the amount of air increases.

If this continues, the excess air ratio will increase and combustion efficiency will inevitably decrease.

However, in this device, if the amount of air increases, the position of the first diaphragm 4 will further fall in the figure, and the spring 1
1 is strongly compressed, the position of the actuator also decreases and the fuel valve hole 1
3 will be wide open.

As a result, the pressure in the secondary gas pressure chamber 16 also rises, and the amount of gas also increases.

In this way, the excess air ratio can be returned to the appropriate value again in a state where the gas amount has increased.

Conversely, when the amount of air decreases, the spring support point rises in the figure, so the second diaphragm 15 also rises a little to reduce the amount of gas, making it possible to maintain the excess air ratio at an appropriate value.

Of course, it is possible to keep the gas pressure at the outlet constant even if the gas pressure fluctuates while the air amount increases or decreases.
Needless to say, this is the same as adjusting the spring fulcrum with a screw structure in a general gas governor.

In this way, it is possible to control the gas input by controlling only the amount of combustion air, and as a result, it is possible to maintain the optimum excess air ratio for combustion.

Further, as shown in the figure, a shutoff valve is provided on the actuator 12, and at the same time, when the air amount is zero, the first diaphragm 4 is closed by the spring 7.
If the design is such that the support point of the governor spring 17, that is, the connecting rod, is separated from the spring 17, the second diaphragm 15 loses pressure from above to below, and the O-ring 19 is moved by the actuator spring 18 to the body 20. The gas was also turned off.

This prevents an accident in which gas is supplied even though air is not flowing, for example, when the blower malfunctions or the intake and exhaust pipes are clogged with foreign matter.

In addition, even if the air does not flow completely, it is possible to cut off the fuel supply even when the air flow is below the lower combustion limit of the combustion section by selecting the design points of the diaphragm, orifice, spring, etc. .

As is clear from the above description, the present invention has a first diaphragm that generates displacement according to the amount of air, and a first diaphragm that operates in conjunction with an actuator that has a shutoff valve that adjusts the opening degree of the fuel valve port in response to fuel pressure. Since it is equipped with two diaphragms and a spring with one side and the other side provided between the first diaphragm and the second diaphragm, changes in air amount can be synchronized with changes in fuel supply pressure.

Therefore, even if the amount of air changes due to voltage fluctuations, fluctuations in intake/exhaust resistance, differences in frequency, etc., the highest efficiency and best combustion can always be maintained, and the rotational speed of the blower or the air circuit The gas input can be adjusted by adjusting the amount of air blown, such as by adjusting the damper installed in the pump.

Furthermore, the fuel supply is automatically stopped when the air supply stops or when the amount of air drops below the combustion range, so it is highly safe.

In this way, not only can the ratio of combustion air and fuel be maintained at an optimum level, but also the operation of the equipment can be stopped simply by operating the air system without providing an on-off valve in the fuel circuit.

Therefore, the electrical circuit system for control can be simplified, and since there is no need to provide an on-off valve in the fuel circuit, no fuel pressure loss occurs due to the on-off valve.

This also simplifies burner design, especially in domestic gas appliances.

[Brief explanation of the drawing]

The figure is a sectional view of a main part of a gas control device according to an embodiment of the present invention. 2...Air orifice, 4...First diaphragm, 7...
... Spring, 13 ... Stomach fuel valve hole, 12 ... Operator, 19 ...
Shutoff valve, 15... second diaphragm, 17... spring, 18... actuator spring.

Claims (1)

[Claims] 1. A first diaphragm that is provided in an air passage and has an air orifice through which air flows; ), a fuel valve hole provided in a fuel path through which fuel flows, an actuator having a valve portion that adjusts the opening degree of this fuel valve hole, and a spring that is biased in the opposite direction to that of the When the pressure is high, a second diaphragm moves the actuator in a direction that reduces the opening degree of the fuel valve hole at its valve portion; and an actuator spring that presses the actuator in the direction of closing the fuel valve hole, one side of the spring is in contact with the second diaphragm, and the other side of the spring is in contact with the second diaphragm. A combustion control device that is connected to be compressed by movement of one diaphragm in a first direction, and controls the amount of fuel supplied according to the amount of air.