JP2018169135A - Gas burner and operation method of gas burner - Google Patents

Abstract

To provide a gas burner capable of forming a stable flame even if abnormal combustion occurs simply by adding a simple configuration.SOLUTION: A jet F for jetting out a premixed gas of flammable gas and air is opened and provided in a burner tip part, a spark generation part 6 is disposed while facing the jet F, an ignition device T for igniting the premixed gas by electric spark generated in the spark generation part 6 is provided, a monitoring part M for monitoring a flame state in the burner tip part is provided, a high-frequency power supply part 5 is provided in the ignition device T, and a power supply control part B capable of applying a high-frequency voltage to the spark generation part 6 by the high-frequency power supply part 5 is provided when it is determined that the flame state is abnormal by the monitoring part M.SELECTED DRAWING: Figure 1

Description

  The present invention provides an opening for opening a pre-mixed gas of combustible gas and air at the tip of the burner, and arranges a spark generation unit facing the injection port, thereby generating electricity generated in the spark generation unit. The present invention relates to a gas burner provided with an ignition device that ignites the premixed gas by a spark, and a method of operating the gas burner.

  As a gas burner, for the purpose of reducing NOx, a so-called premixed gas burner in which a jet outlet for ejecting a premixed gas of combustible gas and air is provided at the tip of the burner is known. In such a gas burner, the ignition of the gas is performed by an ignition device that arranges a spark generating portion facing the jet outlet and ignites the premixed gas by the electric spark generated in the spark generating portion (see Patent Document 1). ).

  According to such an ignition device, it is known that combustion abnormality is likely to occur due to the fact that the combustible gas in the premixed gas is lean. For example, the so-called “lift” in which the flame is not stabilized and rises from the outlet, “combustion vibration”, “lift” or “combustion vibration” that repeats the movement of the flame trying to lift or return to the original state. A “misfire” in which the flame disappears may occur.

  In order to prevent such a phenomenon, it is known to stabilize the flame by trying to re-ignite when abnormal combustion occurs, and an ignition device using a pilot burner is used as an ignition device that enables re-ignition In addition, a combination of an ignition device and a microwave discharge device, which promotes discharge by the microwave discharge device and re-forms a flame in the vicinity of the ejection port, is considered (see Patent Document 2).

Japanese Utility Model Publication No. 2-014544 JP 2009-036197 A

  However, both in the case of using a pilot burner and in the case of using a microwave discharge device, the gas burner has a problem that the system configuration becomes complicated due to an increase in the components of the device. A technique for avoiding this problem has been desired.

  Accordingly, an object of the present invention is to provide a gas burner and a gas burner operating method capable of forming a stable flame even when abnormal combustion occurs only by adding a simple configuration.

The characteristic configuration of the gas burner of the present invention for achieving the above object is as follows:
An opening for ejecting a premixed gas of combustible gas and air is provided at the tip of the burner, and a spark generation unit is arranged facing the injection port, and the preliminary spark is generated by the electric spark generated at the spark generation unit. A gas burner provided with an ignition device for igniting a mixed gas,
Provide a monitoring unit for monitoring the flame state at the burner tip,
The ignition device includes a high frequency power supply unit, and a power supply control unit that allows a high frequency voltage to be applied to the spark generation unit by the high frequency power supply unit when the monitoring unit determines that the flame condition is abnormal. It is in the point prepared.

  According to the above-described configuration, the spark generating part is formed at the tip of the burner by opening the spout for ejecting the premixed gas of combustible gas and air, and the spark generating part is arranged facing the spout. The premixed gas can be ignited by the electric spark. Here, in the generated flame, the fuel is a premixed gas, but the flame state tends to become unstable when the excess air ratio is increased. Therefore, if a monitoring unit that monitors the flame state at the tip of the burner is provided, the destabilized flame can be quickly grasped, which can be an opportunity to stabilize the flame state. Here, if the ignition device is provided with a high-frequency power supply unit, the ignition device can generate sparks at an extremely high frequency compared to a normal power supply. Then, the energy per time that the spark gives to the premixed gas increases, and the contact opportunity between the premixed gas and the spark can be greatly increased. Therefore, even if the flame state becomes unstable, the flame state can be stabilized by applying a high frequency voltage. That is, when the monitoring unit determines that the flame condition is abnormal, the power supply control unit can stabilize the flame by applying a high-frequency voltage to the spark generation unit using the high-frequency power supply unit.

  In addition, if the high frequency voltage of 1 kHz or more and 100 kHz or less can be applied as the power source of the high frequency power supply unit, the chance of contact between the premixed gas and the spark is greatly increased while the device configuration is easily available. Can do.

  If the premixed gas is a city gas mixed with air with an excess air ratio of 1.0 or more and 1.6 or less, when the flame becomes unstable when ignited as a premixed gas, the monitoring unit always sets a flame. When it becomes possible to stabilize, the added value is high.

  Further, in determining the abnormal state, by monitoring at least one monitoring item of the flame emission intensity, the flame temperature, the jet outlet pressure, and the carbon monoxide concentration at the jet outlet as the flame state, the steady state of the monitoring item It is possible to know how much the combustion state is deviated from the steady state by comparing the value of the above and the actual measured value. If the degree of deviation is less than 10%, it is unlikely to lead to misfire, but if it fluctuates 10% or more, it can be judged as an abnormality that leads to misfire (the flame condition is unstable). The stabilized flame can be grasped more quickly, and the flame can be stabilized more reliably.

Further, the gas burner operating method according to the present invention is characterized in that the burner tip is provided with an opening for injecting a premixed gas of combustible gas and air at the tip of the burner, and a spark generating part is disposed facing the outlet. And an operation method of the gas burner provided with an ignition device for igniting the premixed gas by the electric spark generated in the spark generating part,
When the monitoring result of the flame state by the monitoring unit that monitors the flame state at the burner tip is determined to be abnormal,
The high-frequency power supply unit provided in the ignition device applies a high-frequency voltage to the spark generation unit.

  The monitoring unit monitors at least one monitoring item of flame emission intensity, flame temperature, jet outlet pressure, carbon monoxide concentration at the jet outlet as the flame state, and measures each monitoring item. When the value fluctuates by 10% or more compared to the measurement value of each monitoring item when the flame state is in a steady state, the monitoring result of the flame state may be determined to be abnormal. When the monitoring result returns to normal, the high-frequency voltage applied to the spark generation unit may be released.

  That is, since the gas burner of the present invention can be operated so as to maintain a stable flame, the premixed gas can be more stably burned.

  In addition, when the flame is burning stably, if the high-frequency voltage applied to the spark generator is released, the spark generator does not consume power during stable combustion, so that stable combustion is sustained while suppressing power consumption. be able to

  Therefore, it has become possible to provide a gas burner that can form a stable flame even if abnormal combustion occurs by simply adding a simple configuration.

Schematic of gas burner according to an embodiment

  Below, the gas burner concerning the embodiment of the present invention is explained. Preferred examples are described below, but these examples are described in order to more specifically illustrate the present invention, and various modifications can be made without departing from the spirit of the present invention. The present invention is not limited to the following description.

The gas burner according to the present embodiment opens a jet outlet F that ejects a premixed gas G of city gas (an example of a combustible gas) and combustion air (an example of an oxidizing gas) at the tip of a gas supply pipe 4. There is provided an ignition device T in which the spark generating part 6 is arranged facing the jet outlet F, and the premixed gas G is ignited by the electric spark generated in the spark generating part 6.
In addition, the gas burner according to the present embodiment includes a monitoring unit M that monitors the flame state at the burner tip, and the ignition device T includes the high-frequency power supply unit 5 and the power supply control unit B.
In this gas burner operation method, when it is determined that the monitoring result of the flame state by the monitoring unit M that monitors the flame state at the tip of the burner is abnormal, the high frequency power supply unit 5 provided to the ignition device T A high frequency voltage is applied to 6.

[Gas burner]
As shown in FIG. 1, the gas burner is provided in a state of penetrating a furnace wall such as a heating furnace, and heats the space in the furnace, and an oxidizing gas and a fuel gas are supplied to the base end side with a predetermined air. A supply unit 1 for supplying the premixed gas G mixed so as to have an excess ratio is provided, and the premixed gas G supplied to the front end side is jetted into the furnace 2 to form a combustion flame 3 in the furnace 2. This is configured as a gas supply pipe 4 in which a jet outlet F for the purpose is formed.

  In the present embodiment, the gas supply pipe 4 is made of a metal material (for example, stainless steel).

  A spark plug T0 as an ignition device T is inserted into the gas supply pipe 4, and the tip T1 of the spark plug T0 is fixed at a position facing the jet outlet F in the gas supply pipe 4. . The spark plug T0 has a configuration in which a metal electrode member T3 is covered with an insulating layer T4 except for a tip end portion T1 and a base end portion T2, and a high frequency power source portion 5 is provided at the base end portion T2 of the spark plug T0. Are connected to each other so that a spark can be generated in the spark generating section 6 between the tip T1 of the spark plug T0 and the vicinity of the jet outlet F of the gas supply pipe 4.

  Further, an ultraviolet sensor 7 that detects ultraviolet rays emitted from the flame is provided in the vicinity of the jet outlet F of the gas supply pipe 4 to constitute a monitoring unit M that monitors the flame.

  As the high-frequency power supply unit 5, one that can apply a high-frequency voltage of 1 kHz to 100 kHz is preferably used. Specifically, the high-frequency power supply unit 5 that applies a high-frequency voltage of 6 kHz to 20 kHz is easily available. Note that the high frequency power supply unit 5 may be provided in place of the conventional power supply unit capable of applying a voltage of about 60 Hz, or may be provided in combination with the power supply unit.

  Further, as the premixed gas G, city gas in which air is mixed with an excess air ratio of 1.0 to 1.6 is preferably used.

  According to these configurations, when the monitoring unit M determines that the flame is abnormal, the power source control unit B can be operated to apply a high frequency voltage to the spark generation unit 6 using the high frequency power source unit 5. Specifically, it operates as follows.

[Operation method of gas burner]
When it is determined that the monitoring result of the flame state by the monitoring unit M that monitors the flame state at the tip of the burner is abnormal, the high frequency power supply unit 5 provided in the ignition device T applies a high frequency voltage to the spark generation unit 6.

  Specifically, when the flame detection output (flame emission intensity) of the ultraviolet sensor 7 fluctuates by 10% or more compared to the steady output in the steady state, the flame condition monitoring result is determined to be abnormal. By applying a high frequency voltage to the spark generator 6 by the power supply controller B, the state of the flame is stabilized.

That is, when the flame is in a lift state, the flame detection output decreases. Therefore, when this output falls below 90% of the steady output, an operation of applying a high-frequency voltage to the spark generation unit 6 is performed. Can be stably burned at a predetermined position. As long as the high frequency power supply unit 5 at this time applies a high frequency voltage of 6 kHz or more and 20 kHz or less, the effect of stabilizing the flame is recognized, and the same effect is obtained at a high frequency voltage of 1 kHz or more and 100 kHz or less. It was estimated that an effect could be obtained.
If the flame state is stable (or the abnormal combustion converges), it can be determined that the combustion can be continued normally regardless of the spark (the monitoring result of the flame state has returned to normal), and is applied to the spark generation unit 6. Release the high-frequency voltage.

  The ignition device T may be one that discharges with the jet outlet F as a counter electrode, or one that has a spark plug shape having a discharge electrode and a counter electrode.

  As the monitoring unit M, in addition to ultraviolet rays (flame emission intensity), it is possible to detect abnormal combustion by changing according to the flame state such as flame temperature, pressure at the outlet F, and CO concentration at the outlet F. If available.

  Moreover, although the gas burner which radiates and heats the combustion flame 3 directly into the furnace 2 is illustrated in the above embodiment, it is applied to a radiant tube burner which introduces air outside the combustion range into the fuel and burns it premixedly. And can be used to stabilize a wide variety of burner flames.

  The gas burner of the present invention can be used as a gas burner that can form a stable flame even when abnormal combustion occurs due to lean combustion or the like.

5: High-frequency power supply unit 6: Spark generation unit B: Power supply control unit F: Spout G: Premixed gas M: Monitoring unit T: Ignition device

Claims (7)

An opening for ejecting a premixed gas of combustible gas and air is provided at the tip of the burner, and a spark generation unit is arranged facing the injection port, and the preliminary spark is generated by the electric spark generated at the spark generation unit. A gas burner provided with an ignition device for igniting a mixed gas,
Provide a monitoring unit for monitoring the flame state at the burner tip,
The ignition device includes a high frequency power supply unit, and a power supply control unit that allows a high frequency voltage to be applied to the spark generation unit by the high frequency power supply unit when the monitoring unit determines that the flame condition is abnormal. Gas burner provided.   The gas burner according to claim 1, wherein the high-frequency power supply unit can apply a high-frequency voltage of 1 kHz to 100 kHz.   The gas burner according to claim 1 or 2, wherein the premixed gas is a city gas mixed with air at an excess air ratio of 1.0 to 1.6.   The monitoring unit monitors at least one monitoring item of flame emission intensity, flame temperature, jet outlet pressure, carbon monoxide concentration at the jet outlet as the flame state, and a measurement value of each monitoring item is The flame condition monitoring result is determined to be abnormal when the flame condition fluctuates by 10% or more compared to the measured value of each monitoring item when in a steady state. The gas burner described. An opening for ejecting a premixed gas of combustible gas and air is provided at the tip of the burner, and a spark generation unit is arranged facing the injection port, and the preliminary spark is generated by the electric spark generated at the spark generation unit. A method of operating a gas burner provided with an ignition device for igniting a mixed gas,
When the monitoring result of the flame state by the monitoring unit that monitors the flame state at the burner tip is determined to be abnormal,
A gas burner operating method in which a high frequency power supply unit provided in the ignition device applies a high frequency voltage to the spark generating unit.   The monitoring unit monitors at least one monitoring item of flame emission intensity, flame temperature, jet outlet pressure, carbon monoxide concentration at the jet outlet as the flame state, and a measurement value of each monitoring item is 6. The method of operating a gas burner according to claim 5, wherein when the flame state fluctuates by 10% or more compared to the measured value of each monitoring item when in the steady state, the flame state monitoring result is determined to be abnormal.   The method for operating a gas burner according to claim 5 or 6, wherein when the monitoring result of the flame state returns to normal, the high-frequency voltage applied to the spark generation unit is released.

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