JPH01310224A - Control method for burner - Google Patents

Abstract

PURPOSE:To prevent the generation of odor after extinguishment by a method wherein energization of a burner motor is disconnected during OFF operation, and during lowering of the number of revolutions of a motor following disconnection of the energization, a fuel delivery amount of a fuel feed pump is decreased, and thereafter the fuel feed pump is stopped. CONSTITUTION:When a control switch 2 is brought into an OFF operation state, a control part 1 first disconnects energization to a burner motor 5, and the number of revolutions of the burner motor 5 is gradually decreased from a value (R1 or R2) right before OFF operation. The control part 1 determines a combustion amount Q irrespective of a load in response to lowering of the number of revolutions of the burner motor 5, and the running frequency of an electromagnetic pump 10 so that a combustion amount is gradually decreased from a valve (Q1 or Q2) right before OFF operation. when the number r of revolutions of a motor is decreased to 700 r.p.m, the combustion amount Q is reduced to QMIN, and simultaneously energization to the electromagnetic pump 10 is disconnected to stop the pump. This constitution executes extinguishment before a combustion state is worsened, and an amount of generating noxious gas, e.g. CO, is suppressed to a value as low as possible.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a combustion control method for a hot-air heater or the like having a fuel supply pump, a burner motor, and a control section for controlling them.

(b) Conventional technology Traditionally, combustors such as hot air heaters were
As disclosed in Japanese Patent No. 3496, it has a fuel supply pump and a burner motor, and the amount of combustion can be adjusted by changing the amount of fuel and air supplied to the burner.

C) Problems to be Solved by the Invention In the above-mentioned combustor, when extinguishing a fire, the fuel supply pump could be stopped at the same time as the off operation. There was a problem that it easily became gas and remained in the burner, causing a bad odor to waft around.

This invention was made in view of the above facts,
The purpose is to prevent unburned gas from remaining as much as possible when extinguishing a fire, and to suppress the occurrence of bad odors after the fire is extinguished.

(D) Means for Solving the Problems In the present invention, in a method for controlling a combustor that includes a fuel supply pump, a burner motor, and a control unit that controls them, electricity is cut off to the burner motor at the time of an off operation, and the rotation speed of the burner motor thereafter is The fuel supply pump is configured to reduce the fuel discharge amount of the fuel supply pump when the fuel pressure decreases, and then stop the fuel supply pump.

Further, in the present invention, in a method for controlling a combustor that has a fuel supply pump, a burner motor, and a control unit that controls them, and adjusts the combustion amount according to the load, the burner motor is energized at the time of an off operation, and the burner motor is then When the rotation speed of the burner motor decreases, the fuel discharge amount of the fuel supply pump is reduced, and the fuel supply pump is stopped when the rotation speed of the burner motor or the fuel discharge amount of the fuel supply pump becomes a predetermined value or less.

(E) Function With this configuration, the amount of combustion is reduced for a short period of time after the off-operation, and combustion continues while the combustion state is maintained almost in good condition, and then the fire is extinguished. Therefore, much of the fuel supplied to the burner is spent on combustion, and less remains as unburned gas.

In addition, the combustion amount is adjusted according to the load, and if the combustion amount immediately before the off operation is large, the combustion amount is gradually reduced to a predetermined combustion amount after the off operation, and then the fire is extinguished.
Unburnt gas is less likely to remain in the burner, suppressing the generation of bad odors, and extinguishing the fire before the combustion condition worsens, thereby preventing the generation of harmful gas.

(f) Example Hereinafter, embodiments of the present invention shown in the drawings will be described.

FIG. 1 shows a control device for a combustor such as a hot air heater to which the present invention is applied. In Figure 1, (1) is a control unit such as a microcomputer, (2) is an operation switch that supplies on/off operation signals to control unit (1), (3) is a temperature setting device, and (4) is room temperature. The sensor (5) is a burner motor whose operation is controlled by the control unit 1), (6) is a magnet attached to the rotating shaft (7) of the burner motor (5), (F
) is also a fan, (8) is also a rotating body for fuel atomization,
(9) is a rotation speed sensor such as a Hall IC provided close to the magnet (6), and this rotation speed sensor (9)
A pulse signal corresponding to the rotation speed of the burner motor (5) is supplied to the control section (1) from the burner motor (5). (10) is an electromagnetic pump as a fuel supply pump, and this electromagnetic pump (10
) is operationally controlled by the control section (1).

Fig. 2 shows an example of a burner (11) of a combustor. , a burner head (14A) having numerous flame ports (14A) on the peripheral wall.
). At the bottom of the carburetor cylinder (12), there is an air supply port (15) through which combustion air is introduced by the fan (F).
), and a fuel atomizing rotating body (8) and a fuel nozzle (17) for spouting kerosene discharged by an electromagnetic pump (10) are provided in a vaporizing chamber (16) inside the vaporizing tube (12). It has been inserted.

When the control unit (1) is turned on by the operation switch (2), it energizes the vaporization heater (12) and turns on the vaporization cylinder (1).
3. Preheat. When the vaporizer cylinder (13) is sufficiently heated, the burner motor (5) and the electromagnetic pump (10)
energize and start operation. Further, the control unit (1) determines the size of the load according to the difference in temperature between the desired temperature preset by the temperature setting device (3) and the room temperature detected by the room temperature sensor (4), and determines the magnitude of the load as shown in FIG. As shown in the figure, the combustion amount Q suitable for the load is determined in multiple stages or continuously between QMAx and QMIN. Then, the rotation speed of the burner motor (5) is controlled to obtain the amount of air necessary for combustion, and the rotation speed of the burner motor (5) is detected by the signal from the rotation speed sensor (9), and the air amount is adjusted accordingly. The electromagnetic pump (10
) frequency control (for example, about 5 to 20 tones).

In this way, the burner motor (5) and the electromagnetic pump (
When the operation control 10) is performed, combustion air is supplied to the vaporization chamber (16) in the burner (11), and kerosene is sprayed from the spray nozzle (17) toward the rotating body (8). After the kerosene is completely atomized by the rotating body (8), it is vaporized by the heat of vaporization and mixed with air to become a premixed gas.The premixed gas advances to the burner head (14) and (14A), forms a flame (18), and gasifies and burns it.

When the operation switch (2) is turned off, the control unit (1)
First, the burner motor (5) is turned off, and the rotational speed of the burner motor (5) gradually decreases from the value (R1 or R2) immediately before the off operation, as shown in FIG. The control unit (1) also controls the burner motor (5) as shown in FIG.
The combustion amount Q is determined according to the decrease in the rotation speed of the
), the operating frequency of the electromagnetic pump (10) is lowered gradually. And the motor rotation speed R is 70
When it becomes 0r, p, m, the combustion amount Q is Q M I N
At the same time, the electromagnetic pump (10) is turned off to stop it.

According to this embodiment, immediately before the operation switch (2) is turned off, the flame (
18) gradually became smaller as shown by the broken line immediately after the off operation, and disappeared several seconds after the off operation. During this time, the burner head (14) became red hot and the combustion condition was maintained almost in good condition.In addition, the generation of bad odor after extinguishing was significantly reduced compared to the conventional case of extinguishing at the same time as turning off. This is because when the fire is extinguished, the fuel discharge amount of the electromagnetic pump (10) is gradually reduced, and the kerosene that has been spouted out from the spray nozzle (17) becomes unburned gas, making it difficult to remain in the burner (11). Good results were obtained even when strong combustion with a large combustion amount Q was performed.Furthermore, when the motor rotation speed R was approximately 700 r, p, m, the combustion amount Q was Q M
Since the electromagnetic pump (10) was de-energized when it reached IH, the fire was extinguished before the combustion condition worsened, and the C
The generation of harmful gases such as O was suppressed as much as possible.

(G) Effects of the Invention Since the present invention is configured as described above, the amount of combustion is reduced for a short period of time after the off-operation, and the combustion is continued while maintaining a substantially good combustion state, and the combustion is continued after the fire is extinguished. It is possible to prevent a large amount of fuel gas from remaining in the burner, and it is possible to suppress as much as possible the generation of bad odors after the fire is extinguished. In addition, by stopping the fuel supply pump when the rotation speed of the burner motor or the fuel discharge amount of the fuel supply pump becomes less than a predetermined value,
It is possible to extinguish the fire before the combustion condition deteriorates extremely, and it is also possible to suppress the generation of harmful gases as much as possible.

[BRIEF DESCRIPTION OF THE DRAWINGS] The figures relate to one embodiment of the present invention, and FIG. 1 is a block diagram of a combustor control device to which the present invention is applied;
Fig. 2 is a sectional view showing an example of a burner of a combustor, Fig. 3 is an explanatory drawing showing the relationship between load and combustion amount, Fig. 4 is an explanatory drawing showing changes in motor rotation speed during extinguishing a fire, FIG. 5 is an explanatory diagram similarly showing changes in combustion amount. (1)...control unit, (5)...burner motor, (
9)... Rotation speed sensor, (10)... is the fuel pump (fuel supply pump).

Claims (2)

[Claims] (1) In a method for controlling a combustor that includes a fuel supply pump, a burner motor, and a control unit that controls them, the burner motor is energized when the burner motor is turned off, and when the rotation speed of the burner motor subsequently decreases, the fuel discharge amount of the fuel supply pump is reduced. A method for controlling a combustor, the method comprising: reducing the amount of fuel, and then stopping a fuel supply pump. (2) In a method of controlling a combustor that has a fuel supply pump, a burner motor, and a control unit that controls them, and adjusts the amount of combustion according to the load, the burner motor is energized at the time of an off operation, and the subsequent rotation speed of the burner motor is A method for controlling a combustor, comprising reducing the fuel discharge amount of the fuel supply pump when the rotation speed of the burner motor or the fuel discharge amount of the fuel supply pump decreases, and stopping the fuel supply pump when the rotational speed of the burner motor or the fuel discharge amount of the fuel supply pump becomes less than a predetermined value.