JPS60207813A - Pulse burner - Google Patents

Abstract

PURPOSE:To obtain the titled pulse burner capable of preventing continuous combustion and securing an excellent combustibility only due to normal pulse combustion by receiving an emission spectrum of a hydroxyl group by a light receiver to perform discrimination between pulse combustion and continuous combustion. CONSTITUTION:In a combustion chamber 3, air supplied through an air pipe 1 is mixed with a fuel supplied through a gas pipe 4. The gaseous mixture thus produced is exploded by sparks of an ignition plug 8, and pulse combustion is exploded by sparks of an ignition plug 8, and pulse combustion is started. Upoin this occasion, the OH emission spectrum is received by a phototransistor 9, and the OH emission intensity is detected by the output of the phototransistor 9, whereby discrimination between the pulse combustion and the continuous combusrion is performed. If a continuous combustion is decided, a control part 10 closes an electromagnetic switching valve 5 to stop the operation. if a normal combustion is decided the pulse combustion is thereafter continued by a suction operation due to a negative pressure at the time of exhaustion, a fuel suction operation and an igniting operation due to heat of combustion gas feeding back partly from the tail pipe 7 to the combustion chamber 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a pulse combustion line that mixes inhaled 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 level of energy conservation awareness not only in the industrial world but also in home appliances, and there is an increasing demand for higher efficiency in household heat sources. In order to meet these demands, pulse combustion machines that apply pulse jets to combustion and directly utilize the combustion reaction heat have been developed and are being put into practical use.

At the start of operation, air is sucked in by a startup fan, the sucked air is mixed with fuel that is being pumped in, and combustion is started by causing the mixture to explode with a spark from a spark plug. After that, the operation of the startup fan and the spark plug are stopped, but pulse combustion takes place due to the intake action and fuel suction action due to the negative pressure of the exhaust gas after the explosion, and the ignition action due to the heat of the combustion gas partially returned to the combustion chamber. This will continue.

In order to ensure safety, such pulse combustion machines are equipped with a flame detector, such as a flame rond, that detects flame current in the combustion chamber, and immediately stops combustion in the event of a misfire or incomplete combustion. .

[Problems with background technology]

By the way, in such a pulse combustion machine, depending on the shape and arrangement of the combustion chamber, air and fuel are continuously sucked in due to the flame trough effect, etc. For example, the flame is maintained near the fuel intake port, and normal pulse combustion ( Continuous combustion (rather than intermittent combustion) occurs, which may disrupt the supply balance between air and fuel, leading to deterioration in combustibility. However, since Flame Rond also detects red flames, fi flames, and gastritis caused by incomplete combustion during continuous combustion, continuous combustion cannot be detected separately from normal pulse combustion, and combustibility remains poor. The problem was that I kept driving.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The purpose of this is to accurately detect normal pulse combustion and continuous combustion, and to prevent continuous combustion and ensure good combustibility only through normal pulse combustion. Our goal is to provide the following.

[Summary of the Invention] In general, the rate of heat generation by combustion is proportional to the volume of the reactant present in the combustion chamber in a diffusion flame, and the rate of heat generation by combustion is proportional to the volume of the reactant present in the combustion chamber. For example, the air ratio is 0.7 to 1.3.
It has been confirmed that in the practical range of , there is a substantially linear proportional relationship with the emission intensity as shown in FIG.

In view of the above points, this invention attempts to determine the combustion state based on the rate of heat generation.The invention detects the emission spectrum of hydroxyl groups with a photodetector, and detects the emission intensity of hydroxyl groups based on the output of the photodetector. This indirectly detects the heat generation rate, and depending on the detection result, it is determined whether pulse combustion or continuous combustion is occurring, and if it is continuous combustion, then the operation is stopped.

(Embodiment of the Invention) An embodiment of the invention will be described below with reference to the drawings.

As shown in FIG. 2, air passes through an air pipe 1 and an air flapper valve 2 provided in the air pipe 1 to a combustion chamber 2
to go into. On the other hand, fuel (gas) is supplied to the gas pipe 4 and the electromagnetic on-off valves 5 and 5 installed sequentially in the gas pipe 4. The gas enters the combustion chamber 3 through the flapper valve 6. The combustion air and fuel that have entered the combustion chamber 3 are mixed and pulse-combusted. The high-temperature, high-pressure combustion gas thus obtained is supplied through the tail pipe 7 to a heat exchanger (not shown), where heat is removed and then exhausted through an exhaust muffler (not shown). Note that a spark plug 8 is provided in the combustion chamber 3. In addition, for heating to 3, the emission spectrum of hydroxyl groups (wavelength: 3064, hereinafter O
For example, a phototransistor 9 that transmits the above-mentioned OH spectrum is provided. The phototransistor 9 and the electromagnetic coil of the electromagnetic on-off valve 5 are connected to a control section 10.

FIG. 3 shows the circuit configuration of the main part of the control section 10.

First, a DC voltage (2) is applied to the resistor 21 between the collector and emitter of the phototransistor 9. The voltage across the resistor 21 is converted into a rectangular wave by a buffer circuit 22 and supplied to one input terminal of an AND circuit 23 . The output of an oscillation circuit, for example, a bistable multivibrator circuit 24, is supplied to the other input terminal of the AND circuit 23. The output of the AND circuit 23 is then supplied to a counter 25 and counted there. The count value of the counter 25 is determined by the latch circuit 26.
is latched. This latch circuit 26 outputs a voltage at a level corresponding to the latched value, and its output is supplied to the non-inverting input terminal (+) of a comparator (operational amplifier) 27. The output of the multivibrator circuit 24 is delayed by a delay circuit consisting of a resistor 30 and a capacitor 31, and then converted into a rectangular wave by a buffer circuit 32 and supplied to the clear terminal of the counter 25. Further, the output of the multivibrator circuit 24 is directly supplied to the latch circuit 26 as a latch control signal.

Next, the operation in the above configuration will be explained.

When the operation start operation is performed, the control unit 1o starts the startup fan (
(not shown) is operated to supply air into the combustion chamber 3 through the flapper valve 2, thereby exhausting unburned gas and the like in the combustion chamber 3, or buripurging. Thereafter, the engine part 10 operates the electromagnetic on-off valve 5 to open the electromagnetic on-off valve 5 while keeping the startup fan in operation to supply fuel to the combustion chamber 3 through the flapper valve 6 and operate the spark plug 8. Then, the supplied air and fuel are mixed in the combustion chamber 3, and the mixture is exploded by the spark from the ignition plug 8. The high-temperature, high-pressure combustion gas generated by this explosion is supplied from the tail pipe 7 to the heat exchanger, where it is stripped of heat and then discharged. In this case, the explosion generates positive pressure in the combustion chamber 3, closing the flapper valve 2.6 and temporarily stopping the supply of air and fuel. Since negative pressure is generated, the flapper valves 2 and 6 are opened again, and air and fuel are sucked in again. Then, the inhaled air and fuel are mixed and exploded by the spark from the spark plug 8 in the same manner as described above. In other words, pulse combustion is started.

At this time, if normal pulse combustion (intermittent combustion) is performed, the operation shown in FIG. 4 will be performed. That is, the phototransistor 9 is irradiated with the OH emission spectrum in synchronization with pulse oscillation, and each time the phototransistor 9 is irradiated, the phototransistor 9 is
turns on. When “Fu-AI” transistor 9 turns on,
A voltage V1 is generated across the resistor 21, and the voltage V1 is converted into a rectangular wave voltage V2 by a threshold level V ref of the buffer circuit 22. On the other hand, the multi-bye break circuit 24 sequentially outputs the voltage v3 which remains at a high level for a certain period of time. Therefore, when both voltages V2 and V3 are at a high level, the output voltage 4 of the AND circuit 23 is at a high level. Further, a signal obtained by delaying the output of the multivibrator circuit 24 by a time t is output from the buffer circuit 32, and when the output voltage 5 of the buffer circuit 32 rises, the counter 25 is activated by the AND circuit 23.
The output of the counter 25 is counted, and when the voltage 5 falls, the count value of the counter 25 is cleared. Further, the count value of the counter 25 is latched in the latch circuit 26 only while the output voltage (3) of the multivibrator circuit 24 is at a high level. Therefore, during normal pulse combustion, the count value of the counter 25 becomes a certain value or more, and the output voltage of the latch circuit 26 becomes a high level. This voltage is at a higher level than the reference voltage at the interconnection point of resistors 28, 29, so the output voltage of comparator 27 is at a high level. This becomes a determination signal indicating that normal pulse combustion is being performed.

If it is determined that the pulse combustion is normal, the control 110
stops the operation of the startup fan and the operation of the spark plug 8, and from then on, the intake action and fuel suction action are performed by the negative pressure during exhaust, and the ignition action is performed by the heat of the combustion gas partially returned from the tail pipe 7 to the combustion chamber 3. The pulse combustion continues M times.

By the way, if continuous combustion occurs due to some cause such as flame draft effect, the operation shown in FIG. 5 is performed. That is, the phototransistor 9 is continuously irradiated with the OH emission spectrum, and the output voltage v3 of the buffer circuit 22 remains at a high level. Therefore, the output of the ':AND circuit 239 is synchronized with the output of the multivibrator circuit 24, and the count value of the counter 25 ends at '1''.In this way,
During continuous combustion, the count value of the counter 25 becomes less than a certain value, and the output voltage of the latch circuit 26 becomes a low level. This voltage is at a lower level than the reference voltage at the interconnection point of the resistors 28 and 29, so the output voltage of the comparator 27 is at a low level. This is a judgment signal indicating that continuous combustion is occurring. Become.

If it is determined that the combustion is continuous, the control section 10 closes the electromagnetic on-off valve 5 and stops the supply of fuel.

In other words, the operation is stopped.

In this way, noting that the heat generation rate due to combustion has a substantially linear proportional relationship with the OH emission intensity, the OH emission spectrum is received by the phototransistor 9, and the OH emission intensity is determined by the output of the phototransistor 9. In other words, the rate of heat generation is indirectly detected, and this is used to distinguish between pulse combustion and continuous combustion, and in the case of continuous combustion, or incomplete combustion, the operation is stopped at that point, so normal pulse combustion is detected. This will improve combustibility. ; In addition, in the above example, the 0)-1 emission spectrum (wavelength: 306
Although we used a phototransistor that transmits light with a wavelength of 3064 people, it is not limited to this, and other light receivers may be used.For example, in the case of a photomultiplier tube, a filter that transmits light with a wavelength of 3064 people may be provided. .

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.

(Effects of the Invention) As described above, according to the present invention, normal pulse combustion and continuous combustion can be accurately detected, continuous combustion can be prevented, and good combustibility can be achieved by only normal pulse combustion. It can ensure that the pulse burning country can be provided.

, 4. Brief description of the drawings FIG. 1 is a diagram showing the relationship between the thermoluminescence rate and luminescence intensity of hydroxyl groups according to the present invention, FIG. 2 is a schematic configuration diagram showing one embodiment of the present invention, and FIG. 3 is a circuit implementation diagram of the same embodiment, and FIGS. 4 and 58 are time charts for explaining the operation of the same embodiment, respectively.

3... Combustion chamber, 9... Photo 1-rangister (light receiver), 10... Control unit, 25... Counter, 26...
...Latch circuit.

Applicant's agent: Patent attorney Takehiko Suzue Figure 1 0　Haku Sanskrit contribution degree- Figure 3 (− ,,-1

Claims (1)

[Claims] In a pulse burner that mixes air and fuel and burns them in pulses, a light receiver that receives the emission spectrum of hydroxyl groups in the combustion chamber, and a means for distinguishing between normal pulse combustion and continuous combustion based on the output of this light receiver. and a means for controlling operation according to the determination result.