JPH01102218A - Burner - Google Patents

Abstract

PURPOSE:To enable reliable detection of flame failure, by providing a control device which starts combustion at a burner after detection of a no-flame state by means of the detecting means of a burner during starting of operation. CONSTITUTION:When an operation switch 31 is turned ON and the starting of combustion is set, an output from a thermocouple 34 produces an output to detect flame even when flame failure occurs during combustion in a state in which flame is detected by the thermocouple 34 being a flame detecting means before combustion at a burner 15 is started, and since flame failure can not be detected, combustion at the burner 15 is not executed. As a result, since when flame failure occurs to the burner 15, the thermocouple 34 can surely detect flame failure outflow of gas due to flame failure can be reliably prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a combustion device that burns fuel such as gas or kerosene to heat a room or is used in a water heater.

[Prior Art] Combustion devices such as combustion type water heaters and combustion type heating devices burn gas, kerosene, etc. in burners.

In this type of device, the flame of the burner may go out if fuel is temporarily not supplied to the burner or the blower that supplies combustion air stops. When the burner flame is extinguished, an outflow of unburned fuel takes place.

Therefore, in the past, a flame detection means for detecting the presence or absence of a burner flame was provided, and the flame detection means detected a misfire of the burner to control the operation of the combustion device.

[Problems to be Solved by the Invention] However, there is a possibility that an abnormality occurs in the flame detection means and, for example, the flame detection means may issue an output indicating that a flame has been detected even though there is no flame.

Then, even if a misfire occurs during combustion, the flame detection means generates an output indicating that there is a flame, so the misfire cannot be detected, resulting in a problem in that unburned fuel flows out.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a combustion device in which, when a misfire occurs in a burner, a flame detection means can always detect the misfire.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a burner for burning fuel and a flame detection means for detecting the presence or absence of a flame in the burner. The technical means includes a control device that starts combustion in the burner after detecting a non-flame state with a flame detection means.

[Operation and Effects of the Invention] The present invention having the above-mentioned configuration allows combustion to be started if the flame detection means does not detect a flame before starting combustion in the burner when the combustion start setting is performed. start.

Furthermore, when the combustion start setting is made, if the flame detection means detects a flame before starting combustion in the burner, combustion will not be performed.

In other words, if the flame detection means detects a flame before starting combustion, even if a misfire occurs during combustion, the flame detection means will be considered to have detected a flame, and the misfire cannot be detected. , do not perform combustion in a burner.

As a result, if a misfire occurs in the burner, the flame detection means can always detect the misfire, and the outflow of unburned fuel due to the misfire can be reliably prevented.

[Example] Next, a description will be given based on an example in which the combustion device of the present invention is applied to a gas combustion hot air heating device.

FIG. 1 shows a schematic configuration diagram of a gas combustion hot air heating device.

This gas combustion hot air heating device is an indoor open type (generally called a gas fan heater) that burns the air sucked in from the room and blows the combustion gas back into the room. a combustion air circulation path 10 for blowing combustion gas back into the room; and a combustion air circulation path 1
The combustion air circulation path 10 includes a gas supply path 20 for supplying gas into the combustion air, and a control device 30 for controlling the combustion air circulation path 10 and the gas supply path 20 to control the amount of gas combusted.

The above-mentioned combustion air circulation path 10 includes an indoor air intake port 12 equipped with an air filter 11 that guides air from inside the room, and an indoor air intake port 12 that sucks air from the indoor air intake port 12, and the air inside the combustion air circulation path 10 and Blower 13 for flowing combustion gas
, a gas mixing chamber 14 that mixes air and gas, and a gas burner 1 that burns gas above this gas mixing chamber 14.
5, a mixing chamber 16 that mixes the combustion gas combusted by the gas burner 15 and indoor air, and a hot air outlet 17 that blows out the air heated in the mixing chamber 16 as hot air.

The gas supply path 20 includes a gas jet nozzle 21 that jets gas into the gas mixing chamber 14 of the combustion air circulation path 10, a gas supply pipe 22 that guides the gas to the gas jet nozzle 21, and an upstream side of the gas supply pipe 22. A main valve 23 is provided on the side and is opened and closed by energization and de-energization, a safety valve 24 is provided downstream of this main valve 23 and is opened and closed by energization control like the main valve 23, and a safety valve 24 is provided downstream of this safety valve 24. A governor valve 25 is provided to regulate the gas pressure, a proportional control valve 26 is provided downstream of the governor valve 25 and whose opening degree varies depending on the amount of energization, and a proportional control valve 26 is provided downstream of the governor valve 25 to adjust the gas pressure. It consists of a gas bypass 27 having a flow rate adjustment screw 27a that allows a certain amount of gas to flow out from upstream of the proportional control valve 26 to the gas jet nozzle 21.

The control device 30 includes an operation switch 31 that is operated by the user and sets the start and stop of the gas combustion hot air heating device, a room temperature setting means 32 that is set by the user,
Room temperature detection means 33 for detecting indoor temperature, gas burner 1
5, an ignition electrode 35 receives a signal from a thermocouple 34, which is the flame detection means of the present invention, which detects the presence or absence of a flame and the combustion state of the flame, and causes sparks to fly on the combustion surface of the gas burner 15, and the above-mentioned blower. 13, the main valve 23, the safety valve 24, the proportional control valve 26, etc. are energized and controlled. The control device 30 of this embodiment is an electronic control circuit using a microcomputer, and when the device is plugged into a commercial power source (not shown), the power is turned on regardless of the setting state of the operation switch 31. It is something that receives.

Next, the main control portions by the control device 30 according to the present invention will be explained based on the flowchart of FIG. 2.

When the operation switch 31 is turned on, in step S1, it is determined whether or not a post-verge operation (air blowing operation that is performed for a predetermined FR after the burner flame goes out after the heating operation is stopped) is in progress. If this judgment result is YES, in step S2, spark detection by the ignition electrode 35, spark detection, main pulp 23, and safety valve 24 are opened, and the indoor temperature detected by the room temperature detection means 33 is set in the room temperature setting means 32. The opening degree of the proportional control valve 26 and the air blower 1 of the blower 13 are controlled so as to match the set temperature.

Further, if the determination result in step S1 is NO, it is determined in step S3 whether or not the output of the thermocouple 34 is an output that does not detect a flame (for example, 3 mV or less). If the determination result is YES, it is determined that there is no flame in the burner 15 and the process proceeds to step S2. If the determination result is NO, the thermocouple 3
4 is not cooled, or the output of the thermocouple 34 is abnormal, and in step S4, pre-purge (in order to improve the ignitability of the bar 15, the blower 13 is made to blow air for a predetermined period of time before the ignition operation) operation).

Next, in step S5, it is determined whether the output of the thermocouple 34 is an output at which no flame is detected (for example, 3111 V or less). The judgment result is YES
In this case, it is determined that there is no flame in the burner 15 and there is no flame.
Proceeding to step S2, if NO, it is determined in step S6 whether 3 seconds have elapsed since the start of pre-purge. If the result of this determination is NO, it is determined that the thermocouple 34 has not cooled down immediately after the heating operation has stopped, and the process returns to step S5. Also, if the determination result in step S6 is Y
In the case of ES, it is determined that the output of the thermocouple 34 is abnormal and the operation is stopped.

As shown in the above embodiment, when the operation switch 31 is turned on and the combustion start setting is made, the thermocouple 3 serving as the flame detection means
4 is detecting a flame, even if there is a misfire during combustion, the output of the thermocouple 34 is taken as the output that detects the flame, and the misfire cannot be detected. Not executed.

As a result, if a misfire occurs in the burner 15, the thermocouple 34 can always detect the misfire.
Gas outflow due to misfire can be reliably prevented.

Although we have shown an example in which a computer is used as the control device,
An analog electric circuit using transistors, operational amplifiers, etc. may be used.

In addition, in this example, air sucked from indoors is combusted,
Although we have shown as an example an indoor open-type combustion heating device that blows out the combustion gas indoors, there are also FF-type combustion heating devices that exchange heat between the combustion gas and indoor air and release the combustion gas outdoors.
The present invention may also be applied to other combustion devices such as combustion type heating devices incorporating a refrigeration cycle, warm type heating devices, and cooking devices.

Further, although an example in which gas is used as the fuel has been shown, the present invention may also be applied to a heating device that burns other fuels such as kerosene.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a gas combustion heating system, and FIG. 2 is a flowchart showing the main parts of the present invention programmed into a control device. In the figure 15...Gas burner 30...Control device 3
4...Thermocouple (flame detection means)

Claims (1)

[Scope of Claims] A burner for burning fuel and a flame detection means for detecting the presence or absence of a flame in the burner, and at the start of operation, the flame detection means detects a non-flame state and then the burner is activated. A combustion device comprising: a control device for starting combustion of the fuel;