JPH03244918A - Controller for combustion apparatus - Google Patents

Abstract

PURPOSE:To adjust an air-fuel-ratio to a proper value and to enable a burner to perform a normal combustion by a method wherein when a pressure within a combustion box is higher than a pressure of a room, an amount of feeding air of an air feeding fan is increased in reference to a pressure differential signal got from a differential pressure sensor. CONSTITUTION:A differential pressure sensor 6 for outputting a signal corresponding to a differential pressure when a pressure in a combustion box 3 is higher than a pressure in a room A is provided. An amount of feeding air of on air feeding fan 5 is increased in response to a value of the differential pressure signal got from the differential pressure sensor 6. More practically, it is provided with a differential transformer 8 for comparing a pressure in the combustion box 3 with a pressure in the room A to cause a movable core 7 to be displaced in response to the differential pressure, and with an adding circuit 10 for adding a signal of the set number of revolution got from the number of revolution setting circuit 9 for an air feeding fan 5 to an increased amount signal of the number of revolution corresponding to the amount of displacement of the movable core 7 outputted from the differential transformer 8 when the pressure in the combustion box 3 is higher than the pressure in the room A. The air feeding fan 5 is controlled by the number of revolution adding signal outputted from the adding circuit 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a combustor such as a semi-hermetic kerosene stove.

(Prior Art) Conventionally, as a semi-enclosed type kerosene stove, fuel is combusted in a burner that is supplied with indoor air and kerosene supplied by an air supply fan in a combustion case, and the hot air is used for heating. It is known that the exhaust gas inside the combustion casing is discharged outside through an exhaust stack.

(Problem to be solved by the invention) However, in recent years, there has been an increase in the number of highly airtight homes, and combustors are often used while operating ventilation fans. When used as a stove, the pressure inside the combustion chamber may become higher than the indoor pressure (the indoor pressure becomes negative), and in such cases, exhaust gas flows backwards and is not supplied by the air supply fan inside the combustion chamber. There is a disadvantage that there is less air available for combustion, resulting in incomplete combustion in the burner.

Furthermore, when the exhaust gas is prevented from being discharged outdoors due to strong winds, headwinds, etc., or is carried out intermittently, there is the disadvantage that incomplete combustion or fire may occur. In particular, if the fire breaks out, the fuel will continue to be supplied, so the fuel will vaporize due to the heat of the burner, and when the pressure balance is restored, it may spontaneously ignite and cause explosive combustion, which is very dangerous.

(Means for Solving the Problems) The present invention aims to eliminate the above-mentioned inconveniences and dangers, and a combustor control device according to claim 1 supplies indoor air by an air supply fan and also provides a control device for a combustion chamber. In a combustor in which exhaust gas is discharged outside through an exhaust stack, when the pressure inside the combustion chamber becomes higher than the pressure inside the chamber,
A differential pressure detector is installed that outputs a signal according to the pressure difference,
The present invention is characterized in that the amount of air supplied by the air supply fan is increased in accordance with the magnitude of the pressure difference signal from the differential pressure detector.

Further, the combustor control device according to claim 2 provides a combustor that supplies indoor air with an air intake fan and discharges exhaust gas inside the combustion casing to the outside through an exhaust stack. A differential transformer that compares the internal pressure with the indoor pressure and displaces the movable core according to the pressure difference, and a set rotation speed signal from the rotation speed setting circuit of the air supply fan and the inside of the combustion cabinet. and an adder circuit that adds the rotational speed increase signal corresponding to the displacement amount of the movable core output from the differential transformer when the pressure of the movable core is higher than the indoor pressure, and the adder circuit adds The air supply fan is characterized in that the air supply fan is controlled by a rotational speed addition signal.

(Function) According to the control device for a combustor according to claim 1, when the pressure inside the combustion casing becomes higher than the pressure inside the chamber, a pressure difference signal is output from the differential pressure detector, and the pressure difference signal is outputted depending on the magnitude of the pressure difference signal. The amount of air supplied to the air fan is increased, the air-fuel ratio is adjusted to an appropriate value, and the burner performs normal combustion.

Further, according to the combustor control device of claim 2, when the pressure inside the combustion casing becomes higher than the pressure inside the chamber, the movable core of the differential transformer is displaced, and the rotation speed is adjusted according to the amount of displacement. An increase signal is output from the differential transformer, this rotation speed increase signal and a set rotation speed signal from the rotation speed setting circuit are added in an adder circuit, and the rotation speed addition signal is output from the adder circuit. The rotational speed of the air supply fan is increased, the air supply amount of the air supply fan is increased, and the air-fuel ratio is adjusted to an appropriate value,
The burner burns normally.

(Example) Next, an example in which the device of the present invention is applied to a semi-enclosed kerosene stove will be described based on the drawings.

In the drawing, reference numeral 1 indicates a semi-enclosed kerosene stove installed in a room A. The kerosene stove 1 is equipped with a combustion case 3 containing a pot-type burner 2 and an exhaust pipe 4, and is supplied with air in advance by a supply fan 5. The burner 2, which is supplied with indoor air and kerosene, burns fuel and uses the hot air for heating,
The exhaust gas inside the combustion case 3 is discharged to the outside B through the exhaust pipe 4.

Here, the present invention provides a differential pressure detector 6 that outputs a signal according to the pressure difference when the pressure inside the combustion casing 3 becomes higher than the pressure in the room A, and the differential pressure detector 6 outputs a signal according to the pressure difference. The amount of air supplied by the air supply fan 5 is increased according to the magnitude of the pressure difference signal. Specifically, the pressure inside the combustion casing 3 and the pressure inside the room A are compared, and the pressure is A differential transformer 8 in which the movable core 7 is displaced according to the difference, a set rotation speed signal from the rotation speed setting circuit 9 of the air supply fan 5, and the pressure inside the combustion housing 3 are higher than the pressure in the room A. and an adding circuit 10 for adding the rotational speed increase signal output from the differential transformer 8 according to the amount of displacement of the movable core 7, and the rotational speed addition signal output from the adding circuit 10. The air supply fan 5 is controlled by the air supply fan 5.

Next, the above control will be explained in more detail.

Reference numeral 11 designates a pressure fluctuation sensing chamber in which a diaphragm 12 is attached in the middle, a space on one side thereof communicates with the inside of the combustion chamber 3, and a space on the other side communicates with the chamber A. The diaphragm 12 includes: One end of the movable core 7 of the differential transformer 8 is brought into contact.

A stabilizing circuit 13 consisting of a resistor and a constant voltage diode is connected to the primary side of the differential transformer 8 in order to eliminate voltage fluctuations caused by the commercial power supply, and a stabilizing circuit 13 consisting of a resistor and a constant voltage diode is connected to the secondary side of the differential transformer 8. An amplifier circuit 14 is connected.

Reference numeral 15 indicates a drive circuit for the air supply fan 5 with a thyristor 16 interposed therebetween, and the thyristor 16 includes a gate circuit 18 having a photocoupler 17 consisting of a light emitting element 17a and a light receiving element 17b.

The photocoupler 17 generates a sweep waveform as shown in FIG. 3C from the rotational speed addition signal as shown in FIG. 3A from the adding circuit 10 and a full-wave rectified waveform as shown in FIG. It is turned on and off by the output from the comparator 20 which inputs and compares the signal from the comparator 19.
controlled and determines the firing angle of the thyristor 16.

In the figure, 21 represents a ventilation fan, and 22 represents an amplifier within the adder circuit 10.

According to the above configuration, when the semi-enclosed kerosene stove 1 is used while the ventilation fan 21 is operated, under normal conditions when the pressure inside the combustion case 3 is lower than the pressure in the room A, the differential with one end in contact with the diaphragm 12 Since the movable core 7 of the transformer 8 is not displaced and there is no signal from the amplifier circuit 14 for the increase in rotational speed,
Only the set rotational speed signal from the rotational speed setting circuit 9 is input to the addition circuit 10, and the output from the comparator 20 at that time causes the photocoupler 17 to output 0N as shown in FIG. 3d.
- is turned OFF, a voltage as shown in FIG. 3e is applied to the air supply fan 5 by the thyristor 16, the fan 5 rotates at the set rotation speed, and the burner 2 performs normal combustion.

Furthermore, when the pressure inside the combustion casing 3 becomes higher than the pressure inside the room A, the movable core 7 of the differential transformer 8 is displaced, and the amplifier circuit 14 outputs a signal corresponding to the increase in the number of rotations according to the pressure difference. Then, the set rotational speed signal from the rotational speed setting circuit 9 and the rotational speed increase signal from the amplifier circuit 14 are input to the adder circuit 10, and the output from the comparator 20 at that time causes the photocoupler 17 to actuate as shown in FIG. 0N-OFF as shown in f
The thyristor 16 causes the air supply fan 5 to
The voltage shown in is applied, the air supply fan 5 rotates at a rotation speed higher than the set rotation speed, the amount of air supplied by the air supply fan 5 is increased, the air-fuel ratio is adjusted to an appropriate value, and the burner 2 operates normally. Burn.

(Effects of the Invention) As described above, when the combustor control device according to claim 1 is used, when the pressure inside the combustion casing becomes higher than the pressure inside the room, the pressure difference signal from the pressure difference detector is used to control the supply air. Since the amount of air supplied to the fan is increased, the air-fuel ratio is adjusted to an appropriate value, and the burner can always perform normal combustion.

Further, when the combustor control device according to claim 2 is used, when the pressure inside the combustion casing becomes higher than the pressure inside the chamber, the movable core of the differential transformer is displaced, and the rotation speed is adjusted according to the amount of displacement. An increase signal is output from the differential transformer, and an addition circuit outputs a rotation speed addition signal that is the sum of the rotation speed increase signal and the set rotation speed signal from the rotation speed setting circuit, and the rotation speed of the air supply fan is increased. As the number is increased, the amount of air supplied by the air supply fan is increased, the air-fuel ratio is adjusted to an appropriate value, and the burner can always carry out normal combustion.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing an example of implementation when the combustor control device of the present invention is applied to a semi-enclosed kerosene stove, FIG. 2 is a circuit diagram thereof, and FIG. 3 is a time chart thereof. 1... Semi-enclosed oil stove (combustor) 3... Combustion case 4... Exhaust pipe 5... Air supply fan 6
... Differential pressure detector 7 ... Movable core 8 ... Differential transformer 9 ... Rotation speed setting circuit 1 0 ... Addition circuit Patent applicant Sanbot Co., Ltd. Agent Kin Kitamura and three others

Claims (1)

[Claims] 1. In a combustor in which indoor air is supplied by an air supply fan and exhaust gas in the combustion casing is discharged outdoors through an exhaust stack, the pressure inside the combustion casing is A differential pressure detector is provided that outputs a signal according to the pressure difference when the pressure becomes higher than the pressure, and the air supply amount of the air supply fan is increased according to the magnitude of the pressure difference signal from the differential pressure detector. A combustor control device characterized in that: 2. In a combustor in which indoor air is supplied by an air supply fan and exhaust gas inside the combustion casing is discharged outdoors through an exhaust stack, the pressure inside the combustion casing and the pressure inside the room are compared. , a differential transformer whose movable core is displaced according to the pressure difference, a set rotation speed signal from the rotation speed setting circuit of the supply air fan, and the differential transformer when the pressure inside the combustion casing is higher than the indoor pressure. and an addition circuit that adds the rotational speed increase signal corresponding to the displacement amount of the movable core output from the transformer,
A control device for a combustor, characterized in that the intake fan is controlled by a rotational speed addition signal output from the addition circuit.