JPH10238762A - Liquid fuel combustion equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid fuel combustion equipment which always maintains a constant quantity of the fuel which comes from a fuel feeder (especially a nozzle) and prevents the spillage of fuel, by properly controlling the shutdown timing of the fuel feeder (especially a pump) in extinguishing. SOLUTION: The liquid fuel which is fed by a fuel feeder 23 which is operated on the basis of an ON signal and an OFF signal both of which are alternately fed, is vaporized by a vaporizer 21, and this vaporized gas is mixed with the combustion air from a combustion blower 24. A liquid fuel combustion equipment H which ignites this mixed gases by an igniter 22 at a flame formation part to burn them, is provided with a control device 11 which moves to an extinguishing action after the ON signal of the fuel feeder 23 finishes in the extinguishing operation by a shutdown switch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of a fuel supply device for extinguishing a liquid fuel combustion device such as an oil fan heater for forcing a liquid fuel to be vaporized by a vaporizer and burning it, or a forced air supply type hot air heater. It relates to improvement of the device.

[0002]

2. Description of the Related Art As a control of a fire extinguishing operation of a conventional liquid fuel combustion apparatus, as disclosed in Japanese Patent Application Laid-Open No. 2-197760, the liquid fuel supply is immediately stopped during a combustion stop operation. Was common. It should be noted that the unburned portion of the mixed gas during the extinguishing (hereinafter referred to as unburned gas)
It has been known that this unburned gas is released outside the body of the liquid fuel combustion device and smells.

[0003]

However, according to the fire extinguishing operation of the liquid fuel combustion device disclosed in the above publication, the fuel supply device (particularly an electromagnetic pump constituting a part thereof) when the user performs a combustion stop operation The state of) varies, and regardless of this state, the stop operation of the electromagnetic pump for immediate fire extinguishing by the user is performed. Therefore, depending on the state of the electromagnetic pump when the stop signal is input, the plunger The fuel is ejected from the fuel discharge side (and, consequently, the tip end of the nozzle) by the inertial force of the electromagnetic pump, and the time during which this fuel is ejected varies depending on the state of the electromagnetic pump. However, there was a problem that the oil was dripped even when the pump was electrically stopped because the pressure was not constant. In addition, the amount of unburned gas generated differs each time the fire is extinguished, and as a result, the odor generated at the time of extinguishing the fire changes every time the fire is extinguished.

Therefore, in the present invention, by appropriately controlling the stop timing of the fuel supply device (especially the pump) at the time of fire extinguishing, the amount of fuel emitted from the fuel supply device (especially the nozzle) is always maintained constant. It is an object of the present invention to provide a liquid fuel combustion device that prevents dripping of fuel.

[0005]

According to a first aspect of the present invention, a liquid fuel supplied by a fuel supply device operating based on an ON signal and an OFF signal supplied alternately is vaporized by a vaporizer. This vaporized gas is mixed with combustion air from a combustion blower, and the mixed gas is ignited by an igniter in a flame forming section and burned. And a control device for shifting to a fire extinguishing operation after the end of the ON signal.

According to a second aspect of the present invention, a liquid fuel supplied by a fuel supply device operating based on an ON signal and an OFF signal alternately supplied is vaporized by a vaporizer, and the vaporized gas is used for combustion. In a liquid fuel combustion apparatus that mixes with the combustion air from a blower and ignites and burns this mixed gas with an ignition device in a flame forming section, at least at the time of a fire extinguishing operation by an operation off switch, at least the signal is switched from an on signal to an off signal. Is provided with a control device for driving the fuel supply device and the combustion blower.

According to a third aspect of the present invention, the control device immediately shifts to a fire extinguishing operation when it detects that any abnormality has occurred in the liquid fuel combustion device.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail by way of examples, but the present invention is not limited by these examples. Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic perspective view showing an entire configuration of an oil fan heater as a liquid fuel combustion apparatus according to one embodiment of the present invention, and FIG. 2 is a control means for controlling a liquid fuel supply apparatus, a combustion fan and a convection fan. FIG. 3 is a flowchart showing an outline of a control operation of the control means, FIG. 4 is a main flowchart showing an outline of a sequence of a fire extinguishing operation in FIG. 3,
FIG. 5 is a time chart schematically showing signal processing in the fire extinguishing sequence of FIG.

In FIG. 1, reference numeral 1 denotes an outer case constituting a main body of an oil fan heater H, and 2 denotes an outlet for blowing out warm air. A combustion chamber (not shown) is provided in the outer case 1 behind the outlet 2. There are a combustion fan and a convection fan.

In the combustion chamber, fuel is supplied from a fuel tank to a carburetor and a burner head serving as a flame forming portion located above the carburetor (collectively referred to as a burner or a combustion portion). Fuel supply device including an electromagnetic pump and a fuel discharge nozzle, an ignition plug (igniter) as an ignition device, a flame sensor and a carburetor as an ignition and flame detection device for detecting a state of a flame formed in a burner head. A combustion device including a built-in vaporization heater and the like is arranged.

Reference numeral 3 denotes an openable and closable lid for inserting and removing a cartridge tank which is detachably set to a fuel tank (not shown). Reference numeral 4 denotes a switch for instructing the operation of the oil fan heater H by control means to be described later. And an operation panel as an operation unit on which display means such as a lamp and a liquid crystal are disposed, and is provided on the upper surface of the outer case 1.

At the lower part of the back of the oil fan heater H, there are provided an operation board disposed immediately below the operation panel 4 and electric devices such as a control device 10 mounted on a control board, a combustion device, a combustion fan and a convection fan. A power cord for supplying power to the components is provided, and when the plug of the power cord is inserted into an outlet, at least power is supplied to the control device 10, and the operation of inserting the plug into the outlet is described. It is called power-on to distinguish it from the operation of the operation-on switch.

Next, a schematic configuration of a control device 10 centered on a control means 11 for controlling an ignition device, a liquid fuel supply device, a combustion fan and a convection fan will be described.

Reference numeral 10 denotes a control device mainly including a control means 11 which is a main component of the present invention. The control means 11 is a microcomputer (hereinafter simply referred to as a microcomputer) having a timer and a ROM or a RAM as a storage means. It is configured. The control means, i.e., the microcomputer 11 outputs control signals for controlling the operation of various loads based on the input signals. Reference numeral 12 denotes an EEPROM as a storage means which is connected to the microcomputer 11 via a signal line and which can be written at any time. is there. In FIG. 2, the EEPROM 12 is expressed as if it were separate from the microcomputer 11, but this is not a limitation, and the EEPROM may be incorporated in the microcomputer 11 itself.

Various switches 13 to 15 provided on the operation panel 4 and various sensors 16 to 20 provided at appropriate positions are connected to the input side of the control means 11. A vaporization heater 21 incorporated in a burner (specifically, a burner), a spark plug (igniter) 22 as an ignition device, and a part of a liquid fuel supply device for supplying fuel from a fuel tank to a burner (combustion unit). An electromagnetic pump 23, a combustion blower 24 for supplying combustion air to the combustion section, and a convection blower 25 for sucking outside air into the outer case 1 and exchanging heat with combustion gas generated in the combustion chamber and supplying it to the outlet 2 are connected. Have been.

The various switches connected to the input side of the control means 11 include an operation-on switch 13 for instructing the start of operation of the oil fan heater H and extension of the combustion time, an operation-off switch 14 for instructing stop of the operation, and There is another switch 15 for instructing other functions such as a second-speed ignition and a timer.

In the present embodiment, the electromagnetic pump 23 and the combustion fan 2 during the fire extinguishing operation are operated with respect to the operation switch 14.
4 is provided with a function of controlling the respective operations to suppress and control the generation of unburned gas. As a specific example, another switch may be provided independently of the operation switch 14. However, in order to reduce the number of switches on the operation panel, it is preferable to use the same function. Performing the fire extinguishing operation in this control mode enhances the function as the liquid fuel combustion device.

The various sensors include a burner thermistor 16 provided below the burner (more specifically, a vaporizer) for detecting the temperature of the burner. A flame sensor 17 as a flame detection device for detecting a state, a rotation speed sensor 18 for detecting the rotation speed of the combustion blower 24, and a detection of the presence or absence of liquid fuel such as kerosene stored in a fuel tank at a predetermined level or more. There is a liquid level sensor 19 and a room temperature sensor 20 provided near the suction port (not shown) for detecting the temperature of the outside air (that is, room air) drawn into the exterior case 1.

With reference to FIGS. 3 to 5, various operation processes of the control means 11 will be briefly described.

First, in step S1, the operation switch 13 is turned on.
Is turned on to instruct the start of operation, the operation lamp is turned on or the operation mode text is displayed on the liquid crystal display unit in step S2, and the energization of the vaporization heater (for example, the sheathed heater) 21 is started in step S3, and step S4 is performed. It is determined whether the temperature of the vaporizer (specifically, the burner body) is a temperature suitable for the ignition operation (for example, a temperature range of 250 to 270 ° C.), and the energization control of the vaporization heater 21 is continued until the temperature reaches the appropriate temperature. Is reached, the combustion blower (specifically, burner motor) 24 is driven in step S5.

Next, the control means 11 controls the rotation speed sensor 18
The number of revolutions of the burner motor detected at step S1
(For example, 1100 rpm) is determined (step S6). If the specified rotation speed R1 has not been reached, the process proceeds to steps S15 to S16. If the specified rotation speed R1 has been reached, ignition is performed in step S7. The operation is performed, and it is determined in step S8 whether ignition has occurred based on the flame current detected by the flame sensor 17, and in step S9 it is determined whether normal combustion has occurred.

If it is determined in step S8 that the fuel is not ignited or it is determined in step S9 that the combustion is not normal, the process proceeds to steps S17 to S20. If the combustion is normal, the setting of the other switches 15 is performed in step S10. The automatic change operation of the combustion amount is started to set the combustion mode or the set room temperature based on the combustion mode.

In the next step S11, the frame sensor 1
It is determined whether or not the state of the flame at the set combustion amount is normal based on the flame current detected in step 7, and if not, the operation proceeds to steps S21 to S24, and if normal, the operation proceeds to step S12. It is determined whether the operation switch 14 has been operated.

Until the power-off switch 14 is operated in step S12, the operations of steps S10, S11 and S12 are repeated. If the power-off switch 14 is operated, the fire extinguishing operation is performed in the next step S13. The combustion stop operation is completed in S14 and the oil fan heater
H operation stops.

Since it is determined in step S6 that the rotational speed of the burner motor is abnormal, error processing of the burner motor is performed in step S15. This error handling is
For example, the energization of the vaporization heater 21 is stopped, the operation lamp is blinked, or the character of the operation mode on the liquid crystal display section is blinked, and a symbol (for example, E6) indicating the abnormality of the rotation speed of the burner motor is displayed as the abnormality content. Is an operation of notifying the user. In this case, there is no transition to the ignition operation until the abnormality is eliminated. Then, in step S16, the operation can be returned to step S3 via the operation of the operation switch 14 and the operation switch 13 by the user.

In step S8 or step S9, it has been determined that a normal flame cannot be detected within the ignition trial period (for example, 23 seconds) (this is called misfiring). In step S17, misfiring is performed. Will be

In the following step S18, the convection blower 25
In step S19, the drive signal is stopped to stop the combustion blowers 24, and the ignition sequence is terminated.
Then, in step S20, the user's operation switch 14 is turned off.
Then, the operation can be returned to step S3 through the operation of the operation switch 13.

Since it was determined in step S11 that the fire was ignited but the fire was extinguished in the course of changing the combustion amount (this is referred to as mid-fire extinguishing), the process of mid-fire extinguishing is performed in step S21. Subsequently, the drive signal is stopped to stop the convection blower 25 in step S22 and the combustion blower 24 in step S23, respectively, and the combustion amount control sequence ends. Then, in step S24, the operation can be returned to step S3 through the operation of the operation switch 14 and the operation switch 13 by the user.

Here, as an example of the process of misfiring or halfway extinguishing, the operation lamp is blinked or the character of the operation mode on the liquid crystal display is blinked, and a symbol (for example, E1) indicating misfiring is displayed as the abnormality content. A symbol (for example, E2) indicating a fire extinguishing on the way is displayed to notify the abnormality, and the fuel supply operation of the electromagnetic pump 23 is stopped.

Next, the fire extinguishing operation in step S13 will be described in more detail with reference to FIG. First, in step S30, a fire extinguishing signal (combustion OFF
Signal), the combustion is continued until the OFF signal is detected, and if the OFF signal is detected, step S
At 31, an OFF signal generated by operating the operation switch 14 or other signals (for example, a device abnormality such as misfiring).
It is determined whether the signal is an FF signal.

In the case where the operation switch 14 is operated,
It is determined that the signal is a normal fire extinguishing signal, and it is determined in step S32 whether the on-time output of the pump signal has been completed.
The combustion is continued until the output ends, and if the on-time output ends, the drive of the electromagnetic pump 23 is stopped in step S33, while the drive signal (specifically, the phase control signal) to the combustion blower 24 is stopped and turned off. A normal fire extinguishing sequence is started by turning on the odor lamp or displaying a deodorant mode character on the liquid crystal display unit to start a normal fire extinguishing sequence, and then proceeds to step S14.

Here, the combustion mode for continuing the combustion is the combustion mode immediately before the fire extinguishing signal is output (for example, the fixed combustion mode), and the on / off cycle of the pump signal is changed according to the combustion mode. For example, as shown in the time chart of FIG. 5, the on / off cycle is T1 and the on time is T2 (automatically,
If the off time is T1−T2), and if the operation switch 14 is operated during the off time (during the P period after T1 in FIG. 5), the P period (particularly the off time) ends and the next When the on time ends, the drive signal (phase control signal) of the combustion blower 24 is stopped. That is, the time until the drive signal (phase control signal) of the combustion blower 24 is stopped changes depending on the state of the pump signal in which the operation switch 14 is operated. However, it is needless to say that the on-off period T1 is the maximum.

If it is determined that the signal is a fire extinguishing signal due to an operation other than the operation of the operation switch 14 (ie, an abnormality in the appliance), the operation of the electromagnetic pump 23 is immediately stopped in step S34 while the operation of the combustion blower 24 is performed. A fire extinguishing sequence at the time of occurrence of an abnormality for stopping a signal (specifically, a phase control signal) is started, and the process proceeds to step S14. By the way, in the fire extinguishing sequence at the time of occurrence of the abnormality, if the details of the abnormality are separately displayed, it is kind to the user. Also,
As shown in the time chart of FIG. 5, when the error signal is generated at the same time as described above, the drive signals of the electromagnetic pump 23 and the combustion blower 24 are immediately transmitted regardless of the combustion mode. Stopped.

As described above, the combustion operation is continued in a state before the operation from when the operation switch 14 is operated to when the pump signal to the electromagnetic pump 23 is turned off. Then, when the pump signal was switched to OFF, the drive signal to the combustion blower 24 was stopped.
The electromagnetic pump 23 always stops in a state in which fuel is completely discharged from the tip of the plunger (and thus the tip of the nozzle) (that is, a state in which inertial force in a direction of pulling in from the tip side can be expected) at the time of fire extinguishing instruction by operating the operation off switch 14. As a result, the amount of fuel discharged from the nozzle at the time of fire extinguishing can be always kept constant, and oil dripping from the tip of the nozzle due to inertia of the electromagnetic pump has been eliminated.

[0035]

According to the liquid fuel combustion apparatus of the first aspect, conventionally, the pump is immediately stopped at the time of fire extinguishing instruction (specifically, operation of the operation switch off) regardless of the state of the pump signal. Although the end of fuel supply during fire extinguishing (the end time) was unspecified, according to this new control method, the electromagnetic pump was in a state where fuel was completely discharged from the tip of the plunger (and, consequently, the tip of the nozzle). In addition to the fact that the amount of fuel flowing out of the nozzle at the time of fire extinguishing can always be kept constant, oil dripping from the tip of the nozzle due to inertia (or inertia) of the electromagnetic pump is eliminated. In addition, at the end of the ON signal of the electromagnetic pump, the electromagnetic pump is at a maximum distance from the inlet of the electromagnetic pump (in other words, the suction force has been lost). Since the jar has a spring force that automatically returns toward the entrance side, the inertia force in the direction of drawing the fuel is easily applied to the exit side of the fuel (and thus the tip side of the nozzle), and the fuel is discharged. Instead, it can be expected that the fuel will return to the fuel tank side.

As a result, the elimination of oil dripping makes it easier to determine the time required for the fuel remaining after being dropped on the vaporizer to evaporate, and even if there is some variation in the performance of the combustion equipment. In addition, it is possible to control the mixture ratio of the fuel at the time of extinguishing the fire to the last state, and to easily control the mixture ratio of the fuel, thereby improving the fire extinguishing performance. Further, since the mixing ratio of the fuel is stable, the mixed gas, which tends to stay in the burner (specifically, the flame forming portion) when the operation is stopped, is easily burned, and the amount of unburned gas generated is small and its variation is eliminated. The odor at the time of fire extinguishing can be suppressed.

According to the liquid fuel combustion device of the second aspect, at the time of the fire extinguishing operation by the operation off switch, the control device for operating and driving the fuel supply device and the combustion blower at least until the signal is switched from the ON signal to the OFF signal. As a result, the conventional problem that the fuel is stopped immediately and fuel dripping occurs immediately after the fire extinguishing operation is solved as in claim 1, and the switching from the ON signal to the OFF signal is used as a starting point for another operation control. This makes it possible to select and control the mixing ratio of the amount of fuel and the amount of combustion air during the fire extinguishing operation to an appropriate value.

According to the third aspect of the present invention, when any abnormality (ie, error) is detected in the liquid fuel combustion device, the control device immediately shifts to the fire extinguishing operation. However, when this error occurs, so-called fail-safe control that emphasizes safety can be performed more than control that suppresses odor, and it is possible to suppress an increase in danger due to continuous combustion.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an overall configuration of an oil fan heater as a liquid fuel combustion device according to an embodiment of the present invention.

FIG. 2 is a block circuit diagram of a control device mainly including control means for controlling a liquid fuel supply device, a combustion blower, and a convection blower.

FIG. 3 is a flowchart schematically showing a control operation of the control means.

FIG. 4 is a main flowchart showing an outline of a sequence of a fire extinguishing operation in FIG. 3;

FIG. 5 is a time chart schematically showing signal processing in the fire extinguishing sequence of FIG. 4;

[Explanation of symbols]

 H Petroleum fan heater (liquid fuel combustion device) 10 Controller 11 Microcomputer (control means) 21 Vaporization heater (Vaporizer) 23 Electromagnetic pump (Fuel supply device) 24 Blower for combustion 25 Blower for convection

Claims (3)

[Claims] 1. A liquid fuel supplied by a fuel supply device which operates based on an ON signal and an OFF signal supplied alternately is vaporized by a vaporizer, and the vaporized gas is mixed with combustion air from a combustion blower. In a liquid fuel combustion device that ignites and burns this mixed gas with an igniter in a flame forming unit, control for shifting to a fire extinguishing operation after an ON signal of a fuel supply device is completed at the time of a fire extinguishing operation by an operation switch off switch. A liquid fuel combustion device comprising the device. 2. A liquid fuel supplied by a fuel supply device operating based on an ON signal and an OFF signal supplied alternately is vaporized by a vaporizer, and the vaporized gas is mixed with combustion air from a combustion blower. Then, in a liquid fuel combustion device that ignites and burns this mixed gas with an ignition device in a flame forming unit, at the time of a fire extinguishing operation by an operation off switch, at least until the signal is switched from an on signal to an off signal, the fuel supply device and the combustion A liquid fuel combustion device comprising a control device for driving a blower. 3. The control device according to claim 1, wherein the control device immediately shifts to a fire extinguishing operation when detecting that any abnormality has occurred in the liquid fuel combustion device.
The liquid fuel combustion device according to any one of the above.