JP3066256B2 - Oil burning machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil burner such as an oil fan heater for evaporating and burning a liquid fuel and an FF type oil hot air heater.

[0002]

2. Description of the Related Art Conventionally, this type of oil burner has been used in an environment where the air is thin (low oxygen concentration) such as high altitude,
Alternatively, when the external piping for air supply and exhaust of the FF type hot air heater is extended by an extension piping (A in the figure) as shown in FIG. 5, a predetermined amount of air required for combustion is taken into the burner, and the air-fuel ratio is reduced. This may cause incomplete combustion due to collapse, and flame contact may occur such that the ignition flame burns red and comes into contact with the burner cylinder. In order to prevent such abnormal combustion, a microcomputer (hereinafter, referred to as a microcomputer) controlling the combustion operation of the device sets the operating frequency of the fuel pump to a specified amount (for example, a rated value of 10) after a certain period of time after ignition. %) The combustion state was checked by changing the current of the flame rod attached to the carburetor while operating at a low temperature. That is, when the current increases due to a decrease in the operating frequency, it is determined that the combustion has been improved, and it is determined that the combustion is abnormal, and the state in which the operating frequency is lowered is determined as the optimum air-fuel ratio.

[0003]

However, especially at a high altitude or an extremely long external pipe, an appropriate air-fuel ratio must be obtained unless the operating frequency of the combustion pump is greatly reduced to remarkably reduce the refueling amount. However, if the amount of refueling is reduced too much, the calorie itself becomes insufficient in calories, causing troubles such as poor ignition and fire extinguishing on the way.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem and to make it possible to correct a deviation of the air-fuel ratio which cannot be corrected by the conventional method.
An object of the present invention is to provide a highly reliable petroleum combustor capable of performing stable combustion operation even in a severe environment as described above.

[0005]

That is, according to the present invention, there is provided a burner, a frame rod for detecting a flame of the burner, a fuel pump for supplying liquid fuel to the burner, and a combustion fan for supplying air to the burner. The fuel pump, or a microcomputer that controls the operation of the combustion fan to control the amount of combustion of equipment, controlling the fuel pump and the combustion fan to have a preset air-fuel ratio,
Abnormal combustion due to the collapse of the air-fuel ratio is detected by a change in the current value of the flame rod, and in an oil combustor that corrects the air-fuel ratio by reducing the flow rate of the fuel pump, the operating frequency of the fuel pump is detected when abnormal combustion is detected. Lower and more different
When the normal combustion is detected, the previous correction of the operating frequency
At the same time, the rotation speed of the combustion fan is increased.

[0006]

[0007]

[Operation] After the ignition, the microcomputer performs the first correction by lowering the operating frequency of the fuel pump by a specified amount to determine the combustion state after a certain period of time, and checks the current value of the flame rod. If the current value increases, it is determined that abnormal combustion has occurred, and if the current value has decreased, it is determined that normal combustion has occurred. In the case of normal combustion, the operating frequency is returned to the original value, and this is determined as an appropriate air-fuel ratio. In the case of abnormal combustion, after a certain period of time, the operating frequency is further increased by a specified amount.
Lower and check the current value. If the current value decreases,
Return the rotation frequency to the initial correction value to
Determine as ratio. If the current value increases, the operating frequency will be
Return to the initial correction value and set the combustion fan speed to the specified amount.
Raise this to determine this state as the optimal air-fuel ratio.

[0008]

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, an oil burner 1 according to the present invention has a carburetor 2 as a burner body, and a preheater 3 is mounted around the carburetor 2. A burner head 5 is mounted above the vaporizer 2, and an igniter 7 and a frame rod 6 are mounted above the burner head 5.
Is arranged. Further, the carburetor 2 is provided with a combustion fan 9 for supplying combustion air to the carburetor 2 and also connected to a fuel tank 12 via an oil supply pipe 10, and a fuel pump 8 is provided in the middle of the fuel tank 12. . Further, the vaporizer 2 is provided with a temperature sensor 4 for detecting the vaporizer temperature, and the oil burner 1 is further provided with a room temperature sensor 11 at a position directly in contact with the outside air. Although not shown, an operation switch, a display unit, and the like are provided on the operation panel.

A control unit 13 as shown in FIG. 2 is incorporated in the oil burner 1, and the control unit 13 controls the combustion operation of the equipment. In the figure, reference numeral 14 denotes a microcomputer which controls the combustion operation collectively. An operation switch 15, a temperature setting device 16, a temperature sensor 4, a room temperature sensor 11, a frame rod 6 and the like are connected to input ports of the microcomputer 14. I have. On the other hand, the output ports of the microcomputer 14 include the preheater 3, the fuel pump 8, the igniter 7,
Drive systems such as the combustion fan 9 and the display unit 17 are connected.

The oil burner 1 according to the present invention has the above-described configuration, and its operation is as follows. When the operation switch 15 is operated, the microcomputer 14 turns on the power supply to the preheater 3 to preheat the vaporizer 2. A change in the resistance value of the temperature sensor 4 (for example, a thermistor element) attached to the vaporizer 2 is input as a voltage change, and the microcomputer 14 detects this and monitors the temperature rise of the vaporizer 2 due to preheating. In this way, when the temperature of the vaporizer 2 reaches a temperature suitable for vaporizing liquid fuel (petroleum fuel), the microcomputer 14 starts the combustion fan 9 to execute the prepurge, and after the prepurge is completed, the fuel pump 8 and the igniter 7. To start the combustion of the equipment.
That is, when the fuel pump 8 operates, the petroleum fuel in the fuel tank 12 is jetted into the carburetor 2 through the fuel supply pipe 10 and is vaporized by the preheating of the carburetor. Then, the vaporized gas is mixed with air from the combustion fan 9 to become a mixed gas, and is ejected from the burner head 5. The ejected mixed gas is ignited by the discharge spark of the igniter 7, and the combustion operation is started. The microcomputer 14 compares the temperature detected by the room temperature sensor 11 with the temperature set by the temperature setting device 16 even after the ignition,
The fuel supply amount of the fuel pump 8 and the air flow rate of the combustion fan 9 are adjusted according to the temperature difference to control the combustion amount, and the operation is performed so that the room temperature is always maintained at the set temperature.

Further, the microcomputer 14 checks the current value (flame current value) of the flame rod 6 during the combustion operation to monitor the combustion state of the carburetor 2. When an abnormality is detected, the combustion fan 9 stabilizes the combustion of the device.
The operation of the fuel pump 8 is controlled, which is the point of the present invention.

That is, during abnormal combustion, as shown in the combustion amount characteristic diagram shown in FIG. 3, the operating frequency Pf of the fuel pump 8 is lowered, for example, by 10% of the rated value with respect to the current combustion amount (straight line), and the fuel supply amount is reduced. (In the case of a straight line), further increase the rotation speed Fr of the combustion fan 9 by, for example, 5% of the rated value to increase the air flow (in the case of a straight line), and automatically correct the air-fuel ratio to an optimum value to stabilize it. Control the equipment to burn.

The detailed control at the time of the abnormal combustion will be described with reference to the flowchart shown in FIG.

The microcomputer 14 checks the current value (flame current FL1) of the flame rod 6 after a predetermined time has elapsed after executing the combustion operation process and igniting. Next, the combustion pump 8
The operation frequency Pf is reduced by 10% of the rated value to reduce the amount of lubrication, and operation is performed. The flame current value (FL2) is checked again, and this flame current value (FL2) is compared with the previous flame current value (FL1). To determine the current combustion state. That is, if the current value increases (when FL1 <FL2)
Judging that the combustion state has improved, it is now judged to be abnormal,
Conversely, when the current value decreases or does not change (FL1 ≧
In the case of FL2), it is determined that the combustion state has deteriorated and the current state is normal.

In this combustion state determination processing, FL1 ≧ FL2
That is, if the combustion is normal, the operating frequency Pf is raised by 10% to return to the original state, and the air-fuel ratio is determined.
L2, that is, when it is determined that the combustion is abnormal, the operating frequency Pf is further lowered by 10% and the flame current value (FL3) at this time is reduced.
Is checked, and the combustion state is compared again with the previous flame current value (FL2). As a result of comparison, if FL2 ≧ FL3, the microcomputer 14 determines that there is no margin in the flow rate of the combustion pump 8, and raises the operating frequency Pf by 10% (at this time, the operating frequency Pf decreases by 10% from the initial value). Yes), determine the air-fuel ratio as it is. If FL2 <FL3, the microcomputer 14 determines that the flow rate of the combustion pump 8 has a margin,
At the same time, the operating frequency Pf of the combustion pump 8 is increased by 10%, and at the same time, the rotation speed Fr of the combustion fan 9 is increased by 5% of the rated value to increase the amount of air blow, and this is determined as the optimum air-fuel ratio.

The above is the description of the flowchart. Incomplete combustion occurs when the apparatus is used in a low air environment or the supply / exhaust external piping of the FF type hot air heater is excessively extended. According to the present invention, however, it is possible to quickly detect this, control the amount of oil supplied to the carburetor 2 and the amount of air blown to optimal values, and continue stable combustion operation.

[0018]

As described above, according to the present invention, a burner, a flame rod for detecting the flame of the burner,
A fuel pump that supplies liquid fuel to the burner, a combustion fan that supplies air to the burner, and a microcomputer that controls the operation of the fuel pump or the combustion fan to control the amount of combustion of equipment, and is set in advance. Controlling the fuel pump and the combustion fan so that the air-fuel ratio is obtained, detecting abnormal combustion due to the collapse of the air-fuel ratio by a change in the current value of the flame rod, and correcting the air-fuel ratio by reducing the flow rate of the fuel pump. In an oil-fired machine, when abnormal combustion is detected, the operating frequency of the fuel pump is lowered , and
Correction of the operating frequency performed last time when abnormal combustion was detected
And return the combustion fan to a higher speed.
So that the amount of oil supplied to the vaporizer and the amount of air blow are optimal.
Value can be controlled to
Insufficient firing due to lack of calories in the baking machine itself,
Trouble can be solved and high altitude or
Or stable combustion operation even in harsh environments such as extension piping
It becomes possible.

[0019]

[Brief description of the drawings]

FIG. 1 is a schematic structural explanatory view showing one embodiment of an oil fired machine according to the present invention.

FIG. 2 is a block diagram showing a control unit incorporated in the oil combustor shown in FIG.

FIG. 3 is an explanatory diagram showing a combustion amount characteristic corresponding to an operating frequency of a fuel pump and a rotation speed of a combustion fan.

FIG. 4 is a combustion control flowchart of the oil combustor.

FIG. 5 is an external perspective view showing an installation state of the oil burner.

[Explanation of symbols]

 Reference Signs List 1 oil burner 2 carburetor (burner body) 6 flame rod 8 fuel pump 9 combustion fan 14 microcomputer Fr rotation speed of combustion fan FL1 to FL3 current value of flame rod Pf operating frequency of combustion pump

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takashi Saito 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Kazuaki Shimada 2-chome Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Hiroyuki Ieda 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (56) References JP-A-62-258928 (JP, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) F23N 1/02 F23N 5/12 F23N 3/08

Claims (1)

(57) [Claims] 1. A burner, a flame rod for detecting a flame of the burner, a fuel pump for supplying liquid fuel to the burner, a combustion fan for supplying air to the burner, and operation of the fuel pump or the combustion fan And a microcomputer that controls the combustion amount of the device by controlling the fuel pump and the combustion fan so that a preset air-fuel ratio is obtained. In an oil-fired machine that detects the change in current value and corrects the air-fuel ratio by decreasing the flow rate of the fuel pump, the operating frequency of the fuel pump is lowered when abnormal combustion is detected, and when the abnormal combustion is detected, Luck went
A petroleum combustor characterized by returning the rotation frequency correction to its original value and increasing the rotation speed of the combustion fan.