JP3717132B2 - Gas burner for hot water bath type gas heater at city gas governor station - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas burner for a hot water bath type gas heater used when raising the temperature of city gas in a governor station (decompression equipment) in a high-pressure city gas transportation pipeline.
[0002]
[Prior art]
When the city gas in the high-pressure city gas transport pipeline is depressurized at the governor station, the gas itself is reduced in temperature by adiabatic expansion. When the temperature of the gas exiting the governor station falls below 0 ° C, problems with supply failure due to freezing of pipelines and gas decompression equipment, or uplift of the ground due to freezing of soil around buried pipelines and nearby water supply This creates the problem of tube damage.
Therefore, city gas companies have installed hot water bath type gas heaters that heat the gas immediately before the pressure is reduced at locations where the effect of the temperature effect due to the pressure reduction is large.
[0003]
Conventionally, a gas burner that uses a part of the decompressed gas as fuel and heats water in the gas heater is used for the gas heater.
In the case of a conventional gas burner used for such a purpose, the load fluctuation is dealt with by either a proportional control of the main gas burner or an ON / OFF control of the main gas burner.
[0004]
However, if the proportional control of the main gas burner, that the corresponding is technically impossible all ratios in one main gas burner for low NO _X Gas burner conditions. Therefore, in order to cope with high load operation, the main gas burner used from low load to medium load will be changed to a low NO _X type gas burner for medium load to high load operation in the future. It must be replaced.
[0005]
In the case of ON / OFF control of the main gas burner, there is a risk that the pilot burner flame will blow off with the ON / OFF operation of the main gas burner. Therefore, the combustion capacity is limited at low load to medium load. At present, it is put into practical use only within the specified range.
[0006]
[Problems to be solved by the invention]
An object of the present invention, in the gas burner for hot water bath type gas heater in city gas governor stations, achieving low NO _X reduction, and has a wide range of ratios to the load variation, need to be replaced in the future the main gas burner In addition, when the main gas burner is turned on / off, the pilot burner flame is not burned or blown out, and safety and combustion reliability are improved.
[0007]
[Means for Solving the Problems]
The best technical means for solving the above problems are as follows.
1. A main gas burner with a main gas nozzle arranged in a circumferential shape;
Inside the main gas burner, a flame holding gas burner having a flame holding gas nozzle arranged circumferentially,
A flame holder in the center of the flame holding gas burner, set on the tip side thereof, and formed with a flame holding air nozzle on the peripheral surface;
Flame holding gas burner combustion is supported at low load, flame holding gas burner continuous combustion and main gas burner ON / OFF control at medium load, flame holding gas burner and main gas burner continuous combustion at high load in it consists of a corresponding manner the main gas burner and the flame holding gas burner controller for controlling the combustion, the low NO _X type city gas the nitrogen oxide concentration in the combustion exhaust gas generated was configured to reduce the 60ppm or less Gas burner for hot water bath type gas heater at governor station.
[0008]
2. The hot water in the city gas governor station as described in 1 above, wherein the main gas burner has a proportional control function of the gas amount and the air amount in addition to the ON / OFF control, thereby improving the ratio. Gas burner for bath type gas heater.
[0009]
3. The flame holder has an outer peripheral surface facing a flame holding gas nozzle formed toward the center direction, and the outer peripheral surface is formed in a tapered conical shape, on the tip side of the flame holding gas burner, and the main gas burner The hot water bath in the city gas governor station according to 1 or 2 above, wherein a flame holding gas mixing space is formed inside the tip, whereby the flame of the flame holding gas burner never blows off even when the main gas burner is continuously turned on and off. Gas burner for type gas heater.
[0010]
[Action]
In the city gas governor station, when the operation of the hot water bath type gas heater is started, the pilot gas burner is first ignited, and then the flame holding gas burner is ignited to form the flame holding. The pilot gas burner is extinguished and then the main gas burner is ignited to form a main flame. The hot water bath type gas heater warms the water stored in the can in this state, and warms the process gas passing through the heat transfer tube with the warmed water. However, this operation is an operation at a high load.
Next, when the load decreases below a certain value, the controller performs ON / OFF control of the main gas burner, and the flame holding gas burner continues the continuous combustion as it is.
[0011]
Next, when the load further decreases, the controller stops the combustion of the main gas burner and continuously burns only the flame holding gas burner. The flame holding gas burner is controlled to rated combustion, and the main gas burner can improve the ratio by using ON, OFF control and proportional control in combination.
Note that the load fluctuation is detected by detecting the temperature of the hot water in the hot water bath type gas heater with a sensor, and feeding back or feedforward the main gas burner and the flame holding gas burner so that this temperature becomes constant at the set temperature, or a combination thereof. Control.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
A heat transfer tube through which the process gas passes is incorporated in the hot water bath type gas heater filled with water in the can, and the water in the can is heated by the gas burner. The water temperature in the hot water bath type gas heater is maintained constant by changing the combustion amount of the gas burner according to the load fluctuation.
The gas burner ignites the flame holding gas burner with the pilot gas burner and the main gas burner with the flame holding gas burner.
[0013]
The main body portion of the gas burner includes a cylindrical main gas burner cylinder, a flame holding gas burner cylinder formed inside the cylinder, and a main air supply cylinder (burner body) formed outside the flame holding gas burner cylinder. The flame-holding air passage is formed in the space inside the main gas burner cylinder.
A main gas nozzle inclined in the outward diffusion direction is circumferentially arranged at the tip of the main gas burner tube, and the flame holding gas nozzle is formed toward the flame holder side (inside).
[0014]
The flame holder is formed with a tapered surface (conical surface) whose tip is narrowed, and a number of flame holding air nozzles are provided on this peripheral surface. From the air and flame holding gas nozzles ejected from this flame holding air nozzle Combustion is performed by mixing the ejected gas to form a flame holder, and the main flame is formed outside so as to surround the flame holder.
The combustion of the gas burner is all controlled by a controller, and feedback control is fundamental. However, it is also possible to control by feedforward or a combination of this and feedback control.
[0015]
【Example】
1 and 2 show an embodiment of a gas burner 1 according to the present invention, in which 2 is a burner body, 3 is a main gas burner, 4 is a main gas burner cylinder, 5 is a main gas nozzle, 6 is a main gas passage, Reference numeral 7 denotes a main gas supply pipe.
A flame holding gas burner 8 is inserted into the flame holding gas burner cylinder 9 and the flame holding gas burner cylinder 9 set inside the main gas burner cylinder 4. And a flame-holding gas passage 11 formed by the inner cylinder 12 and a flame-holding gas nozzle 10 for injecting gas slightly inward from the front end of the main gas burner cylinder 4.
[0016]
Reference numeral 15 denotes a flame holder set on the front end side of the flame holding air passage 17 formed inside the inner cylinder 12, and this flame holder 15 has a tapered peripheral surface formed so that the front end side becomes narrower. It has a conical shape in which a large number of flame holding air nozzles 16 are formed. Reference numeral 7 denotes a main gas supply pipe connected to the main gas passage 6, and reference numeral 14 denotes a flame holding gas supply pipe connected to the flame holding gas passage 11.
Reference numeral 18 denotes a front side of the gas burner main body 2, which is a main air nozzle arranged circumferentially outside the main gas nozzle 5, 19 is a main air passage, 20 is a pilot gas burner, and 21 is an air supply pipe.
[0017]
FIG. 3 shows a hot water bath type gas heater to which the gas burner 1 is attached. The hot water bath type gas heater 22 includes an outer can 23, a furnace tube 24, a smoke pipe 25, a heat transfer pipe 26, an air opening 27, and a gas inlet. 28, gas outlet 29 and chimney 30 are the main components, and the water filled in the outer can 23 is heated by the combustion gas generated in the gas burner 1, and heated by hot water through the heated gas in the heat transfer tube 26 Heat the gas.
[0018]
FIG. 4 shows a control device (method) of the gas burner 1. The gas supply line 31 is connected to the main gas supply pipe 7 via the main gas supply line 32, and the gas supply line 31 further includes a flame holding gas. The flame holding gas supply pipe 14 is connected via a supply line 35. A main gas proportional control valve 34 and an ON / OFF control valve 33 are attached to the main gas supply line 32, a setting valve 36 is attached to the flame holding gas supply line 35, and the blower 37 and the air supply pipe 21 are connected to each other. The air supply line 38 is connected, and an air proportional control valve 39 is attached to the air supply line 38.
[0019]
Reference numeral 40 denotes a controller. The controller 40 performs the following control.
At the start of operation, the pilot gas burner 20 is ignited, and then the flame holding gas is supplied to the flame holding gas nozzle 10 via the setting valve 36, whereby the flame holding gas burner 8 is first ignited. Then, the pilot gas burner 20 is extinguished, then the ON / OFF control valve 33 is opened and gas is ejected from the main gas nozzle 5 and ignited by the flame holding gas burner 8, thereby the main flame outside the flame holding. Form.
[0020]
The flame holding gas nozzle 10 is controlled by a set valve 36 to supply a constant amount of gas to continuously form flame holding, while the main gas nozzle 5 is controlled by an ON / OFF control valve 33 according to the load. The main flame is formed intermittently or continuously.
At this time, the main gas proportional control valve 34 and the air proportional control valve 39 are simultaneously proportionally controlled, thereby improving the response to the load fluctuation.
[0021]
FIG. 5 is an explanatory diagram of the combustion pattern of the gas burner 1. For example, when set to 20,000 kcal / H, only the flame holding gas burner 8 is burned and set to 150,000 kcal / H. In this case, the combustion of the flame holding gas burner 8 + the output of the main gas burner 3 is controlled to 12.5%, and at the same time, the ON / OFF control valve 33 is controlled to be ON / OFF. For example, when the high load combustion of 1,200,000 Kcal / H is set, the main gas burner 3 is controlled to be fully opened, and the combustion is performed by the combustion of the flame holding gas burner 8 + the combustion of the main burner.
[0022]
【The invention's effect】
As described above, the present invention combines the main gas burner with the flame holding gas burner, and supports the flame holding gas burner at low load, and supports the flame holding gas burner + main gas burner ON / OFF control at medium load. During high loads, flame holding gas burner + main gas burner fully open.
[0023]
As a result, the following effects are obtained.
a. The process gas can be efficiently heated following a wide range of load fluctuations (claims 1, 2, and 3).
b. Since the main gas burner is ignited by a flame holding gas burner having a strong combustion power, there is no fear that the flame holding gas burner will be misfired by turning the main gas burner on and off. Therefore, the gas burner for hot water bath type gas heaters with high safety and reliability can be obtained.
[0024]
c. The ratio is increased by performing proportional control in conjunction with ON / OFF control of the main gas burner (claim 2). Therefore, it is not necessary to replace the main gas burner in the future (claims 1, 2, and 3).
[0025]
d. Combustion of the flame holding gas burner is stabilized by incorporating the flame holding device (claims 1, 2, 3).
e. For remodeling gas burner while leaving the combustion mechanism of the low NO _X gas burner, it is excellent in low NO _X combustibility (claims 1, 2, 3).
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a gas burner according to the present invention.
FIG. 2 is a front view of a gas burner according to the present invention.
FIG. 3 is an explanatory diagram of a gas heater.
FIG. 4 is a conceptual diagram of control of a gas burner.
FIG. 5 is an explanatory diagram of a combustion pattern of a gas burner.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas burner 3 Main gas burner 5 Main gas nozzle 7 Main gas supply pipe 8 Flame holding gas burner 10 Flame holding gas nozzle 15 Flame holding device 16 Flame holding air nozzle 18 Main air nozzle 20 Pilot gas burner 31 Gas supply line 32 Main gas supply line 33 ON / OFF control valve 34 Main gas proportional control valve 35 Flame holding gas supply line 36 Setting valve 37 Blower 38 Air supply line 39 Air proportional control valve 40 Controller

Claims (3)

A main gas burner with a main gas nozzle arranged in a circumferential shape;
Inside the main gas burner, a flame holding gas burner having a flame holding gas nozzle arranged circumferentially,
A flame holder in the center of the flame holding gas burner, set on the tip side thereof, and formed with a flame holding air nozzle on the peripheral surface;
Flame holding gas burner combustion is supported at low load, flame holding gas burner continuous combustion and main gas burner ON / OFF control at medium load, flame holding gas burner and main gas burner continuous combustion at high load in it consists of a corresponding manner the main gas burner and the flame holding gas burner controller for controlling the combustion, the low NO _X type city gas the nitrogen oxide concentration in the combustion exhaust gas generated was configured to reduce the 60ppm or less Gas burner for hot water bath type gas heater at governor station. 2. The city gas governor station according to claim 1, wherein the main gas burner has a proportional control function of the gas amount and the air amount in addition to the ON / OFF control, thereby improving the ratio. Gas burner for hot water bath type gas heater. The flame holder has an outer peripheral surface opposed to a flame holding gas nozzle formed toward the center direction, and the outer peripheral surface is formed in a tapered conical shape on the tip side of the flame holding gas burner. The hot water in the city gas governor station according to claim 1 or 2, wherein a flame holding gas mixing space is formed inside the tip, whereby the flame of the flame holding gas burner never blows off even when the main gas burner is continuously turned on and off. Gas burner for bath type gas heater.

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