JPS60114613A - Pulse burner - Google Patents

Abstract

PURPOSE:To secure the safety of the titled device by a method wherein the burning is stopped when an intake pressure or an inner pressure of a burning part become lower than the designated value. CONSTITUTION:A diaphragm-shaped pressure switch 15 is mounted on an air valve chamber 5. The pressure switch 15 and a flame detector 14 are connected to a control part 20. The control part 20 controls the open/close of a solenoid open/close valve 9. During a burning operation, at the stopping of the normal pulse oscillation owing to some reason, a suitable intake operation is not performed, accordingly, the average pressure in the air valve chamber 5 is lowered down to P3 lower than the designated value Poff. Therefore, an output contact 15a of the pressure switch 15 is made OFF, then the operation of the open/close valve 9 is stopped, therefore, a fuel supply for a burning part 7 is stopped, then the burning is stopped. Thereby, the danger caused by the generation of CO and unburnt gas outflow can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a pulse combustion machine that mixes intake air and fuel, performs pulse combustion, and directly utilizes the combustion reaction heat.

(Technical Background of the Invention) In recent years, there has been an extremely high awareness of energy saving not only in the industrial world but also in home appliances, and there has been an increasing demand for higher efficiency in household heat sources. In order to meet these demands, a pulse combustion machine that applies a pulse jet to combustion and directly utilizes the combustion reaction heat has been developed and put into practical use.

In other words, when a pulse combustion machine starts operating, a startup fan sucks in air (combustion air), mixes the sucked air with fuel, and starts combustion by igniting it with a spark from a spark plug. do. Thereafter, the operation of the startup fan and the spark plug are stopped, but pulse combustion continues due to the intake action due to negative and positive changes during exhaust and the ignition action due to residual heat in the combustion section.

However, in such pulse combustion machines, to ensure safety, a flame detector such as a flame rod is installed in the combustion section, and combustion is stopped when the flame rond current drops below a certain value due to misfire or incomplete combustion. ing.

[Problems with back neck technology]

By the way, in pulse combustion, there are cases where steady combustion continues without normal pulse oscillation.

This is due to the lack of proper air intake, resulting in an extreme lack of air, which results in extremely large amounts of carbon monoxide (Go) being produced.
Also, raw gas may leak out, which is an extremely dangerous situation. However, in this state, the flame rod current is quite large and is not much different from that during normal pulse oscillation, so there is a drawback that combustion continues as it is.

[Problems with background technology]

This invention was made in view of the above circumstances,
The purpose is to provide an excellent pulse combustion machine that can detect steady combustion without normal pulse oscillation, and can immediately stop combustion to ensure safety when this condition occurs. It is in.

[Summary of the invention]

This invention focuses on the fact that during steady combustion without normal pulse oscillation, the average value of the intake pressure or combustion section internal pressure drops below a certain value, and when the intake pressure or combustion section internal pressure falls below a set value, combustion occurs. It is intended to stop.

[Embodiments of the invention]

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

As shown in FIG.
Enter the fan 3 in the air chamber 2. Flapper valve 4. The air passes through the valve chamber 5 and then enters the burner 8 of the combustion section 7 via the air introduction pipe 6. On the other hand, the fuel (gas) is supplied by the electromagnetic on-off valve 9. Governor 10. The gas enters the burner 8 through the gas flapper valve 11.

The air and fuel entering the burner 8 are mixed and pulse-combusted. The high-temperature, high-pressure combustion gas thus obtained is supplied to a heat exchanger (not shown) through the exhaust pipe 12, where heat is removed, and then exhausted through an exhaust muffler (not shown). ing. In addition, in the combustion part 7, 13 is a spark plug, and 14 is a flame detector (flame rod).

A diaphragm-type pressure switch 15 is attached to the air valve cavity 5. This pressure switch 15 and the flame detector 14 are connected to the control section 20.
connected to. This control section 2o controls opening and closing of the electromagnetic on-off valve 9.

FIG. 2 shows the electric circuit of the control section 20. , 21 is an AC power supply, and a fan motor 3M is connected to this power supply 21 via an operation switch 22 and timer contacts 25a, 24a in series.
2. The timer 23 is connected through the timer contact 25a and the output contact 15a of the pressure switch 15 in series. The spark plug 13 is connected to the timer 23 through timer contacts 23a and 24b in series. Further, an electromagnetic on-off valve 9 is connected to the timer 23 via a timer contact 23b.

A timer 24, a flame detector 14, and a timer 25 are connected to the on-off valve 9 via an output contact 14a of the flame detector 14.

Next, the operation of the above configuration will be explained with reference to FIG.

When the operation switch 22 is turned on, the startup fan 3 starts operating, and air is sucked into the air chamber 2 through the intake silencer 1. This air is supplied to the combustion section 7 through the flapper valve 4, the air valve chamber 5 and the air input pipe 6.

As a result, unburned gas remaining in the combustion section 7 is discharged to the outside through the exhaust pipe 12. In other words, prepurge is performed. At this time, the average air pressure in the air valve chamber 5 becomes Pl higher than the set value P00, which turns on the output contact 15a of the pressure switch 15. When the contact 15a is turned on, the timer 23 is activated.

When the timer 23 measures a certain period of time (bripurge time), the timer contacts 23a and 23b close, and the spark plug 13, shutoff valve 9, timer 24, flame detector 14,
and timer 25 respectively operate. In this way, by opening the on-off valve 9, fuel is supplied to the combustion section 7,
In the combustion section 7, it is mixed with air. This gas mixture is ignited by the spark of the spark plug and explodes, and the high temperature, high pressure gas obtained by the m light is supplied from the exhaust pipe 12 to the heat exchanger. In other words, pulse combustion is started. In this case, if normal pulse oscillation occurs, the air valve chamber 5
The average air pressure within increases to P2. When a certain period of time based on the timer 24 has elapsed from the start of pulse combustion,
The timer contacts 24a and 24b are opened, and the operation of the starting fan 3 and the spark plug 13 are stopped. Thereafter, intake is performed by turning on and off the flapper valve 4 based on the positive pressure caused by the explosion in the combustion section 7 and the negative pressure caused by the exhaust.
Further, ignition is performed by the residual heat of the combustion section 7.

By the way, the timer 25 is operating at the same time as the combustion starts, and if the timer 25 measures a certain period of time without the flame detector 14 detecting a flame, the timer contact 25a opens and all operations stop, indicating that the flame is not ignited. Danger is avoided.

Further, when a misfire occurs during combustion, the output contact 14a of the flame detector 14 closes, and when this state continues for a certain period of time based on the timing of the timer 25, the timer contact 25a opens and all operations stop.

Furthermore, if normal pulse oscillation is not performed for some reason during combustion, that is, if proper intake is not performed, the average air pressure in the air valve chamber 5 will be reduced to the set value Poff.
It decreases to P3, which is lower than that of P3.

Then, the output contact 15a of the pressure switch 15 is turned off, the operation of the on-off valve 9 is stopped, and the fuel supply to the combustion section 7 is stopped. In other words, combustion stops.

In this way, by stopping combustion immediately when steady combustion without normal pulse oscillation occurs, it is possible to avoid dangers due to the generation of carbon oxide (CO) and the outflow of raw gas. In addition, the on and off points P on and P oH of the pressure switch 15 are set between the average air pressure P1 obtained by operating the startup fan 3 and the average air pressure P3 of steady combustibility where normal pulse oscillation does not occur. As a result, it is possible to confirm the operation of the starting fan 3, and combustion can be started with the starting fan 3 operating reliably, further improving safety.

In the above embodiment, the pressure switch 15 is attached to the air valve chamber 5 to detect the intake pressure, but it may also be attached to the air introduction pipe 6 to similarly detect the intake pressure. The air pressure inside the combustion section 7 can be detected by attaching it to an arbitrary position of the combustion section 7 or to the burner 8. Further, although a diaphragm-type pressure switch is used, the present invention is not limited to this, and a switch that detects the pulse oscillation waveform itself may be used.

In addition, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without changing the gist.

〔Effect of the invention〕

As described above, according to the present invention, an excellent pulse combustion machine is capable of detecting steady combustion without normal pulse oscillation, and can immediately stop combustion to ensure safety when this condition occurs. can be provided.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an overall configuration diagram, FIG. 2 is a configuration diagram of an electric circuit of a control section, and FIG.
The figure is a diagram for explaining the operation. 3... Starting fan, 5... Air valve chamber, 7...
-Combustion part, 9...Electromagnetic shut-off valve, 13...Spark plug 14...Flame detector. Applicant's agent Patent attorney Takehiko Suzue

Claims (2)

[Claims] (1) A pulse combustion machine that mixes intake air and fuel and pulse-combusts the mixture, characterized in that a means is provided to stop combustion when the average value of intake pressure or combustion section internal pressure falls below a set value. Pulse combustion machine. (2) The pulse combustion machine according to claim 1, wherein the means starts combustion when the intake pressure or the internal pressure of the combustion section exceeds a set value at the start of operation.