JPH06281136A - Control circuit of hot air heater - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize a control device for safe and reliable ignition. [Structure] A heater 17, a burner 5 for burning a vaporized gas of petroleum fuel obtained by heating by the heater, a combustion chamber 3 mounted so as to surround the burner, and combustion air for the combustion chamber. Blower 14 for blowing air
And an igniter 25 for starting combustion of vaporized gas in the burner
A temperature detection thermistor 33 for detecting the temperature of a predetermined portion heated by the heater and rising; an operation input switch 36 for outputting a heating operation start signal; and a heater based on the signal from the operation start instruction means. When the temperature of a predetermined portion that is heated by the heater and rises is started by starting the operation, the temperature detection thermistor is started, and when the detected temperature reaches a predetermined value, the control of the blower is started, and then the igniter. A control circuit for the hot air heater is configured by a microcomputer that starts the control of.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control circuit for an open type oil warm air heater.

[0002]

2. Description of the Related Art In a conventional open type oil warm air heater, fuel petroleum is vaporized and ignited by an igniter at a temperature at which ignition is possible, and the combustion is transferred. After ignition, indoor air is sent to the combustion chamber by a convection blower to heat the room as warm air.

[0003]

When oil is vaporized and ignited, it explosively ignites when the temperature of the vaporized gas is high, and ignites when the temperature is low or the vaporized gas does not flow to the ignition device. Conditions for ignition as a warm air heater are limited, such as difficulty in heating. Also, when re-igniting after failing to ignite once, if the vaporized gas from the previous ignition remains in the vaporization part, the ignition condition will be different from that at the beginning and explosive ignition will result in a dangerous state. was there.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned drawbacks, and includes a heater, a burner for burning vaporized gas of petroleum fuel obtained by heating by the heater, and a burner surrounding the burner. The combustion chamber installed so that the combustion air is blown into the combustion chamber, the ignition unit that starts the combustion of the vaporized gas in the burner, and the temperature of a predetermined portion that is heated by the heater and rises. Temperature detecting means for detecting, operation start instructing means for outputting a start signal of heating operation, and operation of the heater based on the signal of the operation start instructing means, and the temperature of a predetermined portion which is heated by the heater and rises. The detection is started through the temperature detecting means, the control of the blowing means is started when the detected temperature reaches a predetermined value, and then the ignition means is started. In the microcomputer starts controlling constituting the control circuit of the warm air heater.

[0005]

When the operation start instruction means is operated, the microcomputer starts energizing the heater in order to vaporize the petroleum fuel, and starts detecting the temperature of a predetermined portion heated by the heater and rising through the temperature detecting means. . Then, when the detected temperature reaches a predetermined value, the microcomputer drives the air blowing means to cause the air flow that does not hinder the ignition to appear in the combustion chamber. Then, after that, the ignition means is driven to ignite the vaporized gas of the burner.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of the structure of an open type oil warm air heater (hereinafter referred to as an oil fan heater). Reference numeral 1 is a cabinet, 2 is a stand, and 3 is a combustion chamber provided in the cabinet 1. Reference numeral 4 denotes a burner base provided in the lower portion of the combustion chamber 3, reference numeral 5 denotes a burner attached thereto, reference numeral 6 denotes an ignition discharge plug, and reference numeral 7 denotes a flame detection device frame rod, which face flame holes of the burner 5, respectively. Reference numeral 8 denotes a vaporization Bunsen type vaporizer, which has a preheater (not shown) inside. Reference numeral 9 is a cartridge type oil tank, 10 is an oil receiving tray for supporting the same, 11 is an electromagnetic pump, 12 is an oil feed pipe connecting the electromagnetic pump 11 and the carburetor 8, and 13 is a solenoid for operating the opening / closing rod of the nozzle of the burner 5. Is. And 1
Reference numeral 4 denotes a convection blower, which is attached to the back surface of the cabinet 1 and which exchanges heat in the combustion chamber 3 as shown in FIG. 2 (a cross-sectional view of an oil fan heater) and blows out as warm air 14-a.
Then, the wind 14-b for supplying the combustion air to the burner 5 is generated.

FIG. 3 is a control circuit diagram of the present invention, in which 15 is a commercial power source and 16 is an overcurrent fuse. Reference numeral 17 is a preheater for the vaporizer, 18 is a driving triac connected to the heater 17, and 19 is a snubber resistor / capacitor connected in parallel with the triac 18. A phototriac coupler 20 is composed of an output section 20- (a) and an input section diode 20- (b), and a current flows through the input section diode 20- (b), so that an output section 20-
(A) becomes conductive, a current is passed through the gate of the triac 18, the triac 18 is turned on, and the preheat heater 1
Energize 7.

Reference numeral 21 denotes a phototriac coupler, which is composed of an output section 21- (a) and an input section diode 21- (b), and a current flows through the input section diode 21- (b) to cause an output section 21- (b). (A) becomes conductive, and the convection blower 14 is rotated.

22- (a) is a relay contact portion, 22-
(B) is a relay coil. By energizing the coil 22- (b), the contact 22- (a) is closed and the pump circuit 11
Supply power to. 23- (a) is a relay contact part, 23
-(B) is a relay coil. By energizing the coil 23- (b), the contact 23- (a) is closed and the igniter 25 is operated. 24- (a) is a relay contact part, 24-
(B) is a relay coil, and by energizing the coil 24- (b), the contact 24- (a) is closed, and the solenoid 1
3 is operated. The nozzle of the burner 5 is opened and closed by the operation of this solenoid.

Reference numeral 44 denotes a microcomputer, which is programmed to control the oil fan heater. The output part of the microcomputer 44 is connected to the above-mentioned phototriac, relay, and numeral LED 34, and the operation of the timing chart shown in FIG. It is supposed to do.

Reference numeral 26 is a power supply transformer for electronic circuits, which has two power supplies, a flame detection circuit power supply 26- (a) and an electronic circuit DC 12V power supply 26- (b). Reference numeral 27 is a rectifying diode, and 28 is a smoothing capacitor. Reference numeral 29 is a regulator IC for the microcomputer power supply DC5V. 30 is a thermistor for detecting the room temperature, 31 and 32 are resistors for limiting the current, 3
3 is a thermistor for detecting the vaporizer temperature. 34 is a 7-segment 2-digit number display LED for displaying the current room temperature and the set room temperature. 35 to 38 are keys for inputting a microcomputer.
Reference numeral 5 is a drive-off switch, 36 is a drive-on switch, 37 is a room temperature setting up switch, and 38 is a down switch. 39-4
2 is a diode.

A flame detection circuit 43 detects a flame between the frame lot 7 and the burner 5 and inputs it to the microcomputer 44.

Next, the operation of the embodiment of the present invention will be described. When the operation input switch 36 is pressed according to the timing chart of FIG. 6, the oil fan heater starts operation. First, the preheater 17 is energized to start heating the vaporizer. The carburetor temperature is detected by the carburetor temperature detecting thermistor 33, and when it reaches a predetermined value of 160 ° C., the solenoid 13 is energized to close the nozzle of the burner 5. Preheating is further continued, and when the temperature reaches 210 ° C, the ignition operation is started. Here, the blower 14 for convection is 0.
It is operated for 3 seconds. Regarding the operation time of the convection blower 14 and the ignition / ignition performance, as shown in FIG. 4, when the rotation speed of the convection blower 14 is, for example, about 120 rpm or less, there is no effect of purging the retained atmosphere in the combustion chamber, and about 250 rpm. In the above case, a flow of air is left in the burner to the extent that it hinders good ignition, which adversely affects the ignition and causes ignition failure such as not igniting. From this, in order to set the rotation speed of the convection blower 14 in the safe and reliable ignition range, as shown in FIG.
3 seconds is appropriate.

Post-operation pump 1 of this convection blower 14
1. Operate the igniter 25. About 4 after the operation of pump 11
After the oil is filled in the carburetor for 2 seconds, the solenoid 13 is de-energized, the nozzle of the burner is opened, and the air in the combustion chamber is flowing to such an extent that it does not hinder good ignition. Ensures ignition without causing explosive ignition. When ignition is confirmed by the frame rod, the igniter 25 stops its operation, the convection blower 14 is operated again as shown in FIG. 6, and the normal heating operation is started.

[0016]

As described above, according to the present invention, the blower is operated when the temperature of the portion heated and raised by the heater provided for vaporizing the petroleum fuel reaches a predetermined value. By pre-charging the stagnant air in the combustion chamber and generating an air flow in the combustion chamber that does not interfere with ignition, a warm air heater that achieves good ignition without causing explosion ignition is realized.

Further, since the air in the combustion chamber at the time of ignition is in a fluid state, the collision of the combustion flame or combustion exhaust gas generated and diffused by the ignition with the wall surface of the combustion chamber is alleviated, so that complete combustion is promoted and the inner wall of the combustion chamber is deteriorated. Can be effectively suppressed.

[Brief description of drawings]

FIG. 1 is a schematic structural diagram of an oil fan heater according to the present invention.

FIG. 2 is a sectional view of an essential part of an oil fan heater according to the present invention.

FIG. 3 is a control circuit diagram of an oil fan heater according to the present invention.

FIG. 4 is a diagram for explaining the blower rotation speed and ignition performance in one embodiment of the present invention.

FIG. 5 is a diagram illustrating a relationship between a blower energization time and a rotation speed in an embodiment of the present invention.

FIG. 6 is an ignition timing sequence diagram programmed in the microcomputer of the embodiment.

[Explanation of symbols]

 3 Combustion chamber 5 Burner 6 Spark plug 8 Vaporizer 14 Blower 17 Preheater heater 25 Ignition device 33 Vaporizer temperature detection thermistor 36 Operation switch 44 Microcomputer

Claims (1)

[Claims] 1. A heater (17), a burner (5) for burning a vaporized gas of petroleum fuel obtained by heating by the heater, and a combustion chamber (3) mounted so as to surround the burner. A blower means (14) for blowing combustion air to the combustion chamber, an ignition means (25) for starting combustion of vaporized gas in the burner, and a temperature of a predetermined portion heated and raised by the heater are detected. A temperature detecting means (33), an operation start instruction means (36) for outputting a heating operation start signal, and the heater is activated based on the signal of the operation start instruction means, and is heated by the heater to rise. To start the detection of the temperature of a predetermined portion through the temperature detecting means, start the control of the blower means when the detected temperature reaches a predetermined value, A control circuit for a warm air heater, comprising a microcomputer (44) for starting control of the ignition means thereafter.