JPH0629669B2 - Control equipment for combustion appliances - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a combustion appliance such as a hot air heater, and particularly to ignition control.

2. Description of the Related Art Conventionally, in combustion appliances such as warm air heaters, in order to suppress the emission of harmful gases such as carbon monoxide during normal combustion,
The amounts of combustion air and fuel are controlled so that the optimum combustion state is maintained. In recent years, due to increasing awareness of energy-saving energy in burning appliances, there is a demand for burning appliances that can control combustion over a wide range from low-calorie to high-calorie. It is shifting to high-load combustion. Therefore, the flame is liable to lift combustion at the time of ignition due to high load combustion,
Further, it is difficult to improve the ignitability with the air amount and the amount of combustion that are focused on during normal combustion. As a countermeasure against this, there is one in which the settings of the air amount and the combustion amount are changed only at the time of ignition and control is performed so as to shift to normal combustion after the ignition.

An example of such a control device for a combustion appliance will be described below with reference to FIGS. 5 and 6, 101 is a power source,
102 is an operation switch, 103 is a combustion control unit, 104 is an air supply device for combustion air, 105 is a blower for warm air, 1
Reference numeral 06 is a fuel supply device, 107 is an igniter, 108 is a contact of the drive relay of the air supply device 104 and the blower 105, 109 is a contact of the drive relay of the fuel supply device 106 and the igniter 107, and the relay contact 108 , 109 are switched by the combustion control unit 103. Further, the combustion control unit 103 has a normal combustion control unit 110, an ignition control unit 111, and an air amount / combustion amount setting unit 112 at the time of ignition as shown in FIG.
And 113 indicates an ignition detection circuit.

Regarding the control device for the combustion appliance configured as described above,
The operation will be described below. First, the operation switch 102 is O
When the combustion control unit 103 detects that N has been set, the air amount / combustion amount setting unit 112 at ignition sets the air amount and combustion amount at ignition, and turns on the relay contact 108 to turn on the air supply device 104 and the blower. 105 is operated. After a while, the relay contact 109 is turned on to drive the igniter 107 and the fuel supply device 106 to perform the ignition operation. When the ignition detection circuit 113 detects ignition after the start of combustion, the switching unit 113a causes the ignition control unit 1 to operate in the combustion control unit 103 based on this signal.
11 is switched to the normal combustion control unit 110, and the air supply device 104 and the fuel supply device 106 are controlled.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described conventional configuration, even when the same ignition air amount / combustion amount setting, in other words, the same air-fuel ratio, ignition is performed and the operation switch is turned off when the combustion part is cold. Immediately after re-ignition, the ignitability is significantly different. For example, the lower the temperature of the combustion section, the greater the energy required for ignition, the longer it takes to form a flame, and the difficulty of ignition such as difficulty in maintaining flame retention even after ignition, and the transfer of flame from the flame mouth to the flame mouth. It is difficult to ignite. Further, for example, in the case of ignition of a combustor that vaporizes and burns liquid fuel, particularly at low temperatures, the amount of combustion decreases due to dew condensation of the vaporized gas in the combustion section, and the ignitability deteriorates.

Therefore, if the air amount and the combustion amount at the time of ignition of the normal combustion air-fuel ratio are set so that the ignitability in the cold state of the combustion part is optimal, yellow combustion will occur at the time of re-ignition with good ignitability. was there. That is, the amount of air at ignition
The setting of the combustion amount is limited by the yellow combustion condition at the time of re-ignition, and because of this condition, the air-fuel ratio at ignition cannot be lowered sufficiently, and the ignition time is long, and unburned gas is emitted during that period. I felt a bad smell.

The present invention solves the above-mentioned problems, and an object thereof is to shorten the ignition time and to enable optimum combustion.

Means for Solving the Problems In order to solve the above problems, the present invention provides a plurality of ignition time air amount / combustion amount setting units set to air-fuel ratios different from those during normal combustion, at the start of operation or operation. It is configured such that any one of the ignition air amount / combustion amount setting is selected based on a signal obtained from the temperature detection device during a predetermined time after the start.

Operation With this configuration, the present invention enables ignition at an optimum air-fuel ratio according to the temperature of the combustion section based on the signal from the temperature detection device that detects the temperature of the combustion section. Therefore, the ignition time is shortened at the time of ignition, the generation of unburned gas is reduced, and yellow combustion does not occur at the time of re-ignition, so that optimum ignition and optimum combustion can always be obtained.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 1 to 3, 1 is a combustion part, 2 is an air supply device for supplying combustion air to the combustion part 1, 3 is a fuel supply device for supplying fuel to the combustion part 1, and 4 is an igniter. Reference numeral 5 is a temperature detector for detecting the temperature of the combustion section 1. A blower 6 supplies the combustion gas generated in the combustion section 1 as warm air. Reference numeral 7 is a commercial power source, 8 is an operation switch, 9 is a combustion control unit, 10 is a contact of the drive relay of the air supply device 2 and the blower 6, 11 is the fuel supply device 3
And the contact of the drive relay of the igniter 4, this relay contact 1
0 and 11 are switched by the combustion control unit 9. The combustion control unit 9 includes a normal combustion control unit 12, an ignition control unit 13, and an ignition control setting unit 14. The ignition control setting unit 14 has the air-fuel ratio set in the normal combustion control unit 12. There are three types of ignition air amount / combustion amount setting units 15a, 15b, 15c for setting different air-fuel ratios, which are switched by the switching means 16a of the temperature detecting device 16 (including the temperature detector 5 in FIG. 2). Reference numeral 17 denotes an ignition detection circuit, which allows the normal combustion control unit 12 to operate.
And the ignition control unit 13 are switched by the switching means 17a.

In the above configuration, the combustion control unit 9 is configured to perform the sequence operation shown in the flowchart of FIG. That is, in step S1, the operation switch 8 is turned off.
Confirm N / OFF, if OFF, step S
It waits at 1, and if it is ON, it proceeds to step S2. In step S2, the temperature of the combustion section 1 is judged from the output of the temperature detection device 16, and if the output V <V ₁ , the process proceeds to step S5 to select the first ignition air amount / combustion amount setting section 15a. The output of the temperature detection device 16 is V ₁ or more and less than V ₂ (V ₁ ≦ V <
If V ₂ ), the process proceeds to step S6 and the second ignition air amount
If the combustion amount setting unit 15b is selected, and if V ≧ V ₂ in the same manner, the process proceeds to step S7 and the third ignition air amount / combustion amount setting unit 1 is selected.
Select 5c.

When the ignition control setting unit 14 is set as described above, the process proceeds to steps S8, S9, and S10, respectively, and the relay contact 10
Is closed and the air supply device 2 and the blower 6 are turned on to perform pre-purge, and the process proceeds to steps S11, S12 and S13, respectively. In steps S11, S12, and S13, the pre-purge timer is operated, and after a predetermined time, step S1
4, proceeding to S15 and S16, combustion is started. In steps S14, S15 and S16, the relay contact 11 is closed and the igniter 4 and the fuel supply device 3 are turned on.
7, proceed to S18, S19. Steps S17, S18,
In S19, when the ignition detection circuit 17 detects ignition, the ignition control unit 13 is switched to the normal combustion control unit 12, and the process proceeds to Steps S20, S21, S22, respectively, and changes to the normal combustion state. The temperature detecting device 16 is formed by a microcomputer, and judges when the outputs V <V ₁ , V ₁ <V ≦ V ₂ and V ≧ V ₂ of the temperature detector 5 shown in FIG. Select the ignition air amount / combustion amount setting part of any one of the types.

As described above, according to the present invention, based on the signal from the temperature detection circuit that detects the temperature of the combustion part, the ignition air amount / combustion amount of the optimum air-fuel ratio corresponding to the temperature of the combustion part Since it can be set, for example, the temperature of the combustion part is low, the energy required for ignition is large, the time until flame formation is long, and it is difficult to hold the flame even if it is once ignited. In any condition, such as a poor ignitability that the fire does not easily transfer to the mouth, or a condition in which condensation of vaporized gas occurs in the combustion part during ignition of a combustor that vaporizes and burns liquid fuel, especially at low temperatures Ignition characteristics can be improved,
The ignition time is shortened, the generation of unburned gas is reduced, and yellow combustion does not occur at the time of re-ignition, so that optimum ignition and optimum combustion can always be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of essential parts of a control device for a combustion appliance in one embodiment of the present invention, FIG. 2 is a circuit diagram of the control device, and FIG.
FIG. 4 is a cross-sectional view of a heater using the same control device, FIG. 4 is a flow chart of the same control device, FIG. 5 is a circuit diagram showing a conventional control device, and FIG. 6 is a main part of the conventional control device. It is a block diagram. 1 ... Combustion unit, 2 ... Air supply device, 3 ... Fuel supply device, 5 ... Temperature detector, 8 ... Operation switch, 9 ... Combustion control unit, 12 ... Normal combustion control unit, 13 ... Ignition control unit, 14 ... Ignition control setting unit, 15a, b, c ... Ignition air amount / combustion amount setting unit, 16 ... Temperature detecting device.

Claims (1)

[Claims] 1. A combustion part, an air supply device for supplying combustion air to the combustion part, a fuel supply device for supplying fuel to the combustion part, and the air supply device and the fuel supply device are controlled. A combustion control unit for performing combustion and a temperature detection device that detects the temperature of the combustion unit and supplies a signal to the combustion control unit. The combustion control unit includes an ignition control setting unit and a normal combustion control unit. , The ignition control setting unit has a plurality of ignition time air amount / combustion amount setting unit set to an air-fuel ratio different from the air-fuel ratio set by the normal combustion control unit, and at the start of operation or a predetermined time from the start of operation Combustion configured to select one of the ignition air amount / combustion amount setting units based on a signal obtained from the temperature detection device during the subsequent period to ignite with an air-fuel ratio different from that during normal combustion Instrument control device.