JP3127858B2 - Combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus for burning fuel such as kerosene together with air in a combustion chamber, such as a warm air heater.

[0002]

2. Description of the Related Art The above-described combustion apparatus has a combustion chamber hermetically sealed in a container for mixing and burning fuel and air. In this combustion chamber, a combustion section above the burner is arranged. With this burner, the liquid fuel is vaporized, mixed with combustion air, and burned. In the vicinity of the burner, a flame sensor capable of detecting flame during combustion is provided. The combustion state in the combustion chamber can be detected from the output of the flame sensor. For example, if the flame sensor is in an insulated state, no flame is detected and it can be determined that the combustion device is not in a combustion state. If the flame sensor is in the conductive state, the flame is detected and it can be determined that the combustion device is in the combustion state.

However, even when the flame sensor is detecting a flame, the combustion device may not actually be in a combustion state. That is, this is a case where a malfunction occurs in the flame sensor. In such a case, since the combustion state cannot be confirmed by the flame sensor, the operation of the combustion device is stopped. After that, for example, the cause is investigated and maintained by a service person, and after the malfunction of the flame sensor is eliminated, the combustion device is operated. However, since various causes are assumed for the above-described malfunction of the flame sensor, it took time to investigate and maintain the cause.

[0004] It is therefore an object of the present invention to solve the above-mentioned technical problems and to provide a combustion device capable of quickly eliminating the malfunction of the flame sensor.

[0005]

According to a first aspect of the present invention, there is provided a combustion apparatus for vaporizing a liquid fuel.
Combustion equipped with a carburetor heater that raises the temperature in the vicinity of the carburetor, a container-like combustion chamber that mixes and burns fuel gas and air inside, and a flame sensor that is provided in the combustion chamber and detects a flame. In the apparatus, a drying unit for drying the flame sensor, a detecting unit for detecting a malfunction of the flame sensor, and a flame sensor in response to the detection unit in response to the detection unit so that condensation of the flame sensor can be eliminated. case, further comprising a control means for operating the drying means, the drying means
It is characterized by including a vaporizer heater .

[0006] In some cases, the flame sensor for detecting the combustion state of the combustion device malfunctions. The inventor of the present application has found that condensation may occur in the flame sensor as a cause of this failure. That is, the combustion gas containing water vapor may accumulate in the combustion chamber after combustion. For this reason, when dew condensation occurs in the combustion chamber and water droplets resulting from the dew condensation adhere to the flame sensor, the flame sensor is always short-circuited, for example, and becomes undetectable.

[0007] According to the above configuration, when the flame sensor malfunctions, the drying means automatically and quickly operates. If the drying unit dries the flame sensor and dew forms on the flame sensor, the dew can be quickly eliminated. Therefore, it is possible to quickly eliminate malfunctions such as the failure of the flame sensor to be detected due to condensation. In particular, the vaporizer heater
The temperature near the vaporizer is raised by the
Can be dried quickly. Moreover, gasification combustion
The vaporizer heater, which is an essential component for the combustion of the device,
Since it is used as a drying means, the structure can be prevented from becoming complicated.
You. A combustion apparatus according to a second aspect of the present invention is the combustion apparatus according to the first aspect, further comprising an air supply fan for supplying air for combustion into the combustion chamber.
It is characterized by being included in the drying means.

According to this structure, in addition to the effect of the invention according to claim 1, the supply air is heated by the carburetor heater,
And a state of being more dry, oxygen Runode, flame sensors blowing supply air were the dried flame sensor by the air supply fan
It can be dried quickly . In addition, since the air supply fan, which is an essential component for the combustion of the combustion device, is used as the drying means, the structure can be simplified as compared with the case where a separate drying means is provided.

According to a third aspect of the present invention, in the combustion apparatus according to the second aspect, the control means includes a flame detector.
When operating the air supply fan when the sensor is malfunctioning,
It is characterized in that the air flow by the fan is suppressed . According to this configuration, a decrease in the temperature of the supply air can be suppressed.

According to a fourth aspect of the present invention, in the combustion apparatus according to any one of the first to third aspects, when the control means does not eliminate the malfunction of the flame sensor even by operating the drying means. And a notifying means for notifying that effect. According to this configuration, claims 1 to 3
In addition to the operation of the invention according to any one of the above, since the operation failure of the flame sensor cannot be eliminated by the drying means, it is reported that the cause of the operation failure is other than condensation, for example, soot. Can be determined based on

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a forced supply / exhaust type hot air heater as a combustion device according to an embodiment of the present invention. This warm air heater draws in the cold air in the room from a suction grill 2 arranged below the front surface 1a of the warm air heater main body 1, and the front air 1 of the warm air heater main body 1
The hot air is blown out from the blow-off grill 3 arranged at the upper part of FIG.

A combustion chamber 4 for burning gasified liquid fuel is provided inside the warm air heater main body 1. A burner 5 is disposed below the combustion chamber 4, and a combustion section 6 of the burner 5, which is formed of a cylindrical wire mesh, is disposed in the combustion chamber 4.
Is incorporated within. FIG. 2 is a schematic diagram of the burner of FIG. In the casing of the burner 5, a vaporization chamber 7, a fan chamber 8 and a motor chamber 9 which are communicated with the combustion chamber 4 through the combustion section 6 described above are defined. The vaporizer 10 is constituted by a portion of a casing that partitions the vaporization chamber 7 and a stirring blade 16 arranged in the vaporization chamber 7. A vaporizer temperature sensor 11 composed of a thermistor for detecting the vaporizer temperature is disposed on a wall surface of the vaporizer 10 or the like. The liquid fuel pressurized and supplied by the electromagnetic pump 12 through the oil feed pipe 13 is injected to the rotary cone 14, atomized by centrifugal force generated by the rotation of the rotary cone 14, and then pre-evaporated by the vaporizer heater 15. Heated vaporization chamber 7
The gas is stirred by the stirring blade 16 and gasified.

The fan chamber 8 accommodates an air supply fan 17 for supplying air supplied from outside to the combustion chamber 4 as combustion air. In the motor chamber 9, a burner fan motor 18 composed of a DC motor for driving the air supply fan 17,
An air supply temperature sensor 19 for detecting the temperature of the air supply is housed.

Referring to FIG. Above the combustion chamber 4, a heat exchanger 20 connected to the combustion chamber 4 is arranged. A convection fan 21 is provided below the combustion chamber 4 for blowing cold air in the room sucked from the suction grill 2 to the above-described combustion chamber 4 and the heat exchanger 20 and convection into the room through the blow grill 3. I have. This convection fan 2
1 is driven by a convection fan motor 22.

Please refer to FIG. 1 and FIG. An electrode plug 23 for ignition is arranged near the flame port 24 of the combustion section 6. The electrode plug 23 has a transformer 25 for the igniter.
And a high voltage is applied thereto. Also,
A flame rod type flame sensor 2 close to the flame outlet 24
6 are arranged.

An oil leveler 27 is connected to a fuel tank (not shown) installed outdoors or the like via a pipe 28 and an oil filter 29. Above the oil leveler 27, the above-described electromagnetic pump 12 is arranged. A room temperature sensor 30 is arranged in the hot air heater main body 1 at a position near the suction grill 2. In the vicinity of the combustion chamber 4 in the hot air heater main body 1,
An overheating prevention thermo 31 is provided. Further, the burner fan motor 18 is provided with a rotation speed sensor 32 for detecting the rotation speed. The convection fan motor 22
Is provided with a rotation speed sensor 33 for detecting the rotation speed. The rotation speed sensors 32 and 33 are configured using, for example, a Hall element or the like.

An exhaust pipe 34 connected to the above-described heat exchanger 20 and an air supply pipe 35 connected to the motor chamber 9 of the above-described burner 5 are led out of the main body 1 of the hot-air heater. Exhaust cylinder 36 (also called air supply / exhaust top)
It is connected to the. The supply / exhaust cylinder 36 is formed of a double cylinder attached to a wall surface. The inside of the inner cylinder is an exhaust passage 37, and the annular passage between the inner cylinder and the outer cylinder is an air supply passage 38.

In the hot air heater having such a configuration, the fuel supplied and vaporized by the electromagnetic pump 12 is supplied to the vaporizing chamber 7 through the air supply passage 38 and the air supply pipe 35 of the air supply / exhaust cylinder 36.
The combustion air supplied to the inside is mixed, and the air-fuel mixture is burned at the flame port 24 of the combustion unit 6. The combustion exhaust gas is supplied to the exhaust passage 37 of the heat exchanger 20, the exhaust pipe 34 and the supply / exhaust pipe 36.
It is discharged outside through.

An operation panel 40 provided with various operation switches 39 and a display section 41 is disposed below the blow grill 3 on the front surface 1a of the warm air heater main body 1. On the back side of the operation panel 40, Operation related to setting of operating conditions by various operation switches 39 and display of the display unit 41
An operation board 42 including a display circuit 50 (see FIG. 3) and the like is arranged.

On the other hand, the operation board 42 and the various sensors 11, 19, 26, 3
A control board 43 including a control circuit 49 (see FIG. 3) for controlling the operation of the electromagnetic pump 12, the burner fan motor 18, and the convection fan motor 22 in response to signals from 0, 31, 32, 33,. Have been. Next, the main electrical configuration of the present hot air heater will be described with reference to the block diagram of FIG.

The control circuit 49 is constituted by a microcomputer including a CPU 46, a RAM 47, a ROM 48 and the like mounted on the control board 43. Control circuit 49
And the operation / display circuit 50 are connected to each other so that signals can be exchanged between the two circuits. The control circuit 49 receives signals from various operation switches 39 via the operation / display circuit 50 and outputs signals for display to the display unit 41.

The control circuit 49 includes a vaporizer heater 1
5. The burner fan motor 18 and the like are connected, and a signal is output to them. Control circuit 49
Is connected to the vaporizer temperature sensor 11, the flame sensor 26, and the like, and signals from these sensors are input. The flame sensor 26 can detect the combustion state using the conductivity of the flame. That is, when a predetermined voltage is applied to the flame sensor 26 in a state where there is a flame, the flame sensor 26 becomes conductive, and the CPU 46 that has received a signal corresponding thereto can determine the combustion state. On the other hand, when there is no flame, the flame sensor 26 is in an insulated state, and the CPU 46 having received a signal corresponding thereto can determine that it is not in the combustion state. For this purpose, the flame sensor 26 has a tip portion provided at a position where the flame sensor 26 can come into contact with the flame ejected from the flame outlet 24. When a predetermined voltage is applied to the tip portion, whether or not a conduction current or an insulated state can be determined based on whether or not a minute current equal to or greater than a predetermined value flows, and as a result, the presence or absence of a flame can be determined.

By the way, there is a case where insulation failure occurs in the flame sensor 26 and operation failure occurs. As a cause of the malfunction, there is a case where dew condensation occurs on the flame sensor 26. That is, the combustion gas containing water vapor may be accumulated in the combustion chamber 4 after the combustion. Therefore, the combustion chamber 4
When dew condensation occurs in the inside and water droplets due to the dew condensation adhere to the flame sensor 26, the flame sensor 26 is always short-circuited, for example, and becomes undetectable.

In response to such insulation failure, the hot air heater uses a drying means D for drying the flame sensor 26 so that dew condensation on the flame sensor 26 can be eliminated, and an operation failure of the flame sensor 26. And a detecting means E for detecting.
The CPU 46 as the control means can operate the drying means D in response to the detection means E when the flame sensor 26 malfunctions.
In the warm air heater of the present embodiment, it is performed in a pre-operation process.

The details will be described below. The drying unit D includes the above-described air supply fan 17 and the above-described carburetor heater 15. When the air supply fan 17 is operated, the air is taken in from outside through the air supply pipe 35, passes through the flame opening 24 in the casing of the burner 5, and is blown to the flame sensor 26. Thereby, the flame sensor 26 can be dried. In addition, when the air supplied by the air supply fan 17 passes through the vaporization chamber 7, it can be heated by the vaporizer heater 15 and blown to the flame sensor 26 in a more dried state. It can be dried quickly.

The detecting means E comprises a circuit 26a connected to the flame sensor 26 for detecting the flame. The circuit 26a is provided in the control circuit 49.
As shown in Steps S1 and S5 in the control contents described later, the detection operation of the flame sensor 26 is performed in a state where there is no flame. The presence or absence can be detected.

Next, the control contents of the above-described pre-operation processing will be described with reference to the flowchart of FIG. When the operation start command of the hot air heater is input to the operation switch 39,
The burner fan motor 18 is operated, and prepurge for exhausting the fuel gas in the burner 5 is performed. In this state, there is no flame since it has not yet been ignited.

In step S1, the presence or absence of a malfunction of the flame sensor 26 is detected by the detecting means E. That is,
In a state where there is no flame, the flame sensor 26 performs a detecting operation. For example, a current value (frame current value) flowing through the flame sensor 26 to which a predetermined voltage is applied is detected. If the frame current value is equal to or less than a predetermined value, for example, 50 μA, the flame is in an insulated state, and the flame sensor 26 in this state detects that there is no flame and can determine that the flame is normal.

If the flame sensor 26 is normal (OK in step S1), the pre-operation processing ends. Thereafter, fuel and combustion air are supplied, ignited, and normal combustion operation is performed. Next, it is assumed that insulation failure occurs in the flame sensor 26. In this case, even if there is no flame, the flame sensor 26 is in a state of detecting the flame, so that the flame sensor 26 is in the state of being undetectable. For poor insulation,
There are cases where the above-mentioned dew condensation is caused and cases where soot is caused. Hereinafter, each case will be described separately.

In the case of insulation failure due to condensation, in step S1, the frame current value exceeds a predetermined value (NG in step S1), and if the flame sensor 26 is determined to be insulation failure, immediately, The drying operation by the drying means D is performed. In the drying operation, the vaporizer heater 15 is energized under predetermined conditions, for example, until the temperature detected by the vaporizer temperature sensor 11 reaches a predetermined temperature (step S2).
At the same time, the air supply fan 17 is operated by driving the burner fan motor 18 (step S3). The burner fan motor 18 at the time of this drying operation is operated, for example, at a rotation speed of 60% of the rated operation. This is because if the amount of air supplied by the air supply fan 17 is too large, an increase in the temperature of the vaporization chamber 7 is suppressed even if the vaporizer heater 15 is energized, and the temperature of the air supply cannot be sufficiently increased. This is assumed. For this reason, the air volume at the time of the drying operation is suppressed, and a decrease in the supply air temperature is suppressed.

In step S4, the above-described drying operation is continued until a predetermined time elapses, for example, for 60 seconds from the time when the insulation failure of the flame sensor 26 is detected. Here, the above-mentioned predetermined time is determined by the air supply fan 17 and the carburetor heater 1.
The time is set such that the dew condensation of the flame sensor 26 is eliminated by the drying operation by 5 and the insulation state of the flame sensor 26 can be restored.

Thus, the flame sensor 26 is dried. Then, as a result of the dew condensation occurring on the flame sensor 26 being eliminated, the insulation failure of the flame sensor 26 is also eliminated.
Next, in step S5, the insulation state of the flame sensor 26 is determined based on the frame current value as in step S1. As described above, since the insulation failure has been resolved (OK in step S5), the pre-operation processing ends. In this case, since the flame sensor 26 has returned to normal,
The ignition and the combustion operation are performed.

Next, a description will be given of a case of insulation failure due to a cause other than dew condensation, for example, soot. Also in this case, in step S1, the flame current value becomes equal to or more than the predetermined value (NG in step S1), the flame sensor 26 is determined to be defective, and the drying unit D performs a drying operation (steps S2 to S2). 4). Thus, the flame sensor 26 is dried, but the insulation failure of the flame sensor 26 is not eliminated.

Next, the insulation state of the flame sensor 26 is determined in step S5, and as described above, since the insulation failure has not been eliminated (NG in step S5), the operation is stopped. That is, the vaporizer heater 15 is stopped (Step S6), and the burner fan motor 18 is stopped (Step S7). Then, a predetermined error code is displayed on the display unit 41 including a liquid crystal display element or the like as a notification unit (step S8). This error code is NG in step S5.
That is, based on the fact that the insulation state of the flame sensor 26 cannot be recovered even by the drying operation, it is notified that the insulation failure has occurred in the flame sensor 26 due to a cause other than dew condensation. When a reset operation is performed by operating the operation switch 39 of the operation panel 40 (YES in step S9), the error code displayed in step S8 is stored in a storage unit such as the RAM 47 stored and held by a battery. After that (step S10), the pre-operation process ends, and the warm air heater stops.

In the warm air heater in this state, the flame sensor 26
In order to eliminate the malfunction of, maintenance by a service person or the like will be performed. At this time, the error code stored in step S10 is read from the RAM 47, and is notified to the service person or the like by the display unit 41.
A service person or the like can easily and promptly determine that the cause of the stoppage of the hot air heater is insulation failure of the flame sensor 26 due to a cause other than dew condensation based on the above error code. Therefore, measures such as maintenance
It can be done accurately and quickly.

As described above, according to the present embodiment, if there is an insulation failure in the flame sensor 26, the drying means D automatically operates promptly, and the drying means D dries the flame sensor 26.
In particular, when dew condensation occurs on the flame sensor 26, the dew condensation can be quickly eliminated by the drying operation. Therefore, operation failures such as inability to detect the flame sensor 26 due to dew condensation can be quickly eliminated, so that even if dew condensation occurs, the combustion device can be quickly operated without any trouble.

Further, since the drying means D uses the air supply fan 17 which is an essential component for combustion of the warm air heater, the structure can be simplified as compared with the case where a separate drying means is provided. Further, the drying means D warms the air supplied by the air supply fan 17 by the carburetor heater 15,
Since it is sprayed on the flame sensor 26 in a more dried state,
The flame sensor 26 can be dried quickly. In addition, since the carburetor heater 15, which is an essential component for the combustion of the gasification combustion device, is used as the drying means, the structure can be prevented from becoming complicated.

On the basis of the above-mentioned predetermined error code display on the display unit 41 and the content of the predetermined error code stored in the RAM 47, the cause of the malfunction of the flame sensor 26 is other than condensation, for example, soot. You can judge that. As a result, it is possible to perform a measure for resolving the malfunction in an accurate and prompt manner. In the above-described embodiment, the drying unit D includes the air supply fan 17 and the carburetor heater 15, which are essential components of the combustion device. However, the drying unit D may be provided separately from the configuration for combustion. . In short,
The drying means D only needs to be able to dry the flame sensor 26.

In the above-described embodiment, the operation error is notified by displaying a predetermined error code on the display unit 41, but the mode of the notification is not limited to this. For example, a display by a lamp or a sound of an alarm buzzer may be used. In addition, various design changes can be made without changing the gist of the present invention.

[0040]

According to the first aspect of the present invention, a vaporizer is provided.
By drying the flame sensor using the heater, the malfunction of the flame sensor due to dew condensation can be quickly eliminated, so that even when dew condensation occurs, the combustion device can be operated quickly without any trouble. it can. Besides, burning
Since a vaporizer heater for air conditioning is used as drying means,
The structure can be prevented from becoming complicated. According to the invention according to claim 2, in addition to the effect of the invention according to claim 1, a vaporizer heater is provided.
The air supply whose temperature has been increased using
Spraying the flame sensor efficiently dries the flame sensor.
Can be dried. In addition, by drying the flame sensor using a combustion air supply fan, the structure can be prevented from becoming complicated.

According to the invention of claim 3, claim 2
In addition to the effects of the invention according to
By reducing the temperature of the air supply,
Preferred for drying the sensor. According to the invention according to claim 4, in addition to the effect of the invention according to any of claims 1 to 3, it is possible to determine that the cause of the malfunction of the flame sensor is other than dew condensation, so that the malfunction is eliminated. Can be performed accurately and promptly.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a forced supply / exhaust type hot air heater as a combustion device according to an embodiment of the present invention.

FIG. 2 is a schematic view of a burner of the hot air heater of FIG. 1;

FIG. 3 is a block diagram of an electric configuration of the warm air heater of FIG. 1;

FIG. 4 is a flowchart of control contents of the hot air heater of FIG. 1;

[Explanation of symbols]

 Reference Signs List 4 combustion chamber 10 carburetor 15 carburetor heater 17 air supply fan 26 flame sensor 41 display unit (notification unit) 46 CPU (control unit) D drying unit E detection unit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F23N 5/12

Claims (4)

(57) [Claims] 1. A temperature near a vaporizer (10) for vaporizing a liquid fuel.
Flame sensor for detecting the vaporizer heater (15) for raising the container-shaped combustion chamber to burn by mixing the fuel gas and air in the inner part (4), a flame is provided in the combustion chamber (4) in the (26), the flame sensor (26), so as to eliminate the condensation of the flame sensor (26)
The drying means (D) for drying (26), the detecting means (E) for detecting malfunction of the flame sensor (26), and the flame sensor (26) operate in response to the detecting means (E). in the case of failure, drying means (D) further and control means for operating (46) the provided, the drying means (D) is a combustion apparatus which comprises a vaporizer heater (15). 2. The combustion apparatus according to claim 1, further comprising an air supply fan (17) for supplying combustion air into the combustion chamber (4), wherein the air supply fan (17) is a dry air supply fan. A combustion device, which is included in the means (D). 3. The combustion device according to claim 2, wherein the control means (46) is provided when the flame sensor (26) is malfunctioning.
When operating the air supply fan (17), the wind generated by the air supply fan (17)
A combustion device characterized in that the amount is reduced. 4. The combustion apparatus according to claim 1, wherein the control means (46) does not eliminate the malfunction of the flame sensor (46) even if the drying means (D) is operated. A combustion apparatus characterized by including a notifying means (41) for notifying at that time.