JPH0665706U - Exhaust gas recirculation control device for burner - Google Patents

Abstract

(57) [Summary] [Purpose] NOx with a simple structure that changes depending on the amount of combustion.
Provided is an exhaust gas recirculation control device for a burner, in which the value does not change depending on the combustion amount and can be set to any NOx value. [Structure] An opening degree of a damper 44 provided on the exhaust system side of the blower 30 in the exhaust gas recirculation path 42 and two solenoid valves provided in parallel in the middle of the path of the fuel gas supply pipe 14 to the burner 10. The amounts of exhaust gas and combustion gas supplied to the combustion chamber 12 are controlled by interlocking with the opening / closing amounts of 16 and 18. [Effect] By setting the opening degree of the opening / closing valve according to the number of opening / closing solenoid valves, the supply amount of exhaust gas can be adjusted in accordance with the supply amount of fuel gas with an extremely simple structure. Even if the combustion amount is changed, an arbitrary NOx value can be maintained.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a burner exhaust gas recirculation control device, and more particularly, to a burner exhaust gas recirculation control device that can arbitrarily maintain the NOx value of the exhaust gas discharged from the burner.

[0002]

[Prior art]

 A known burner system for recirculating exhaust gas is shown in FIG. The burner 80 used in this system is provided in the combustion chamber 81. The burner 80 is supplied with the fuel gas 82 through the fuel gas supply pipe 83, and the exhaust gas circulation pipe 84 operates the blower 85. Combustion air 86 is supplied through air ports 87, 88, 89. When the air-fuel mixture is burned by the ignition of the burner 80, a combustion flame 90 is formed in the combustion chamber 81, and the exhaust gas 91 accompanying the combustion is discharged through the exhaust pipe 92 and the exhaust top 93. Part of the exhaust gas 91 is returned to the burner 80 via the damper 94 and the pipe 84. The amount of exhaust gas 91 returned to the burner 80 is adjusted by the opening of the damper 94, and the supply amount of the fuel gas 82 is adjusted by the opening of the solenoid valves 95, 96.

[0003]

[Problems to be solved by the device]

 However, the conventional system has a problem that the NOx value also changes when the combustion amount is changed by the burner. That is, as shown in FIG. 6, when the combustion amount increases, the NOx value decreases, and when the combustion amount decreases, the NOx value increases. The NOx value changes in this way, for example, when the combustion amount increases, the pressure in the exhaust stack rises, and thus the circulation amount of the exhaust gas increases.

The object of the present invention is a simple structure, the NOx value which has been changed by the combustion amount does not change by the combustion amount, and can be set to any NOx value. It is to provide a circulation control device.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention supplies combustion air and fuel gas to a burner, mixes them, and injects this mixture into the combustion chamber for combustion to generate exhaust gas due to combustion. In the exhaust gas recirculation control device of the burner, which has an exhaust gas recirculation path that discharges this exhaust gas to the burner and returns a part of this exhaust gas to the burner, and installs a blower in the middle of the exhaust gas recirculation path, The opening degree of the on-off valve provided on the exhaust system side of the blower in the gas recirculation path is linked with the opening and closing amounts of the multiple solenoid valves installed in parallel in the middle of the fuel gas supply pipe to the burner. And controlling the supply amounts of the exhaust gas and the combustion gas supplied to the combustion chamber.

[0006]

[Action]

 According to the above configuration, the opening degree of the opening / closing valve in the exhaust gas recirculation path and the opening / closing amounts of the plurality of solenoid valves provided in the fuel gas supply pipe are linked, so that the exhaust gas supplied to the combustion chamber and the The supply amount of combustion gas can be adjusted. Therefore, the NOx value that has changed depending on the combustion amount does not change with the combustion amount, and can be set to any NOx value. Moreover, it is only necessary to change the opening degree of the damper according to the number of open solenoid valves, and it is possible to control with an extremely simple structure.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the burner 10 is provided in the combustion chamber 12 and is connected to the fuel gas supply source via the fuel gas supply pipe 14. In the middle of the fuel gas supply pipe 14, branch pipes 15a and 15b are provided, and solenoid valves 16 and 18 are provided respectively to be connected to the fuel gas supply pipe 14, and the solenoid valves 16 and 18 By appropriately opening the valve, the fuel gas 20 from the fuel gas supply source is injected from the flame port 22 through the fuel gas supply pipe 14. Further, the burner 10 is provided with a plurality of air ports 24, 26, 28, and the fuel air 32 is supplied from the air ports 24, 26, 28 by the operation of the blower 30.

When the combustion air 32 and the fuel gas 22 are mixed in the burner 10 and the burner 10 is ignited, a combustion flame 34 is formed in the combustion chamber 10 and the exhaust gas 36 accompanying the combustion of the air-fuel mixture is formed. Are discharged from the exhaust stack 38 and the exhaust top 40. An exhaust gas recirculation path 42 for returning a part of the exhaust gas 36 to the burner 10 is connected to the exhaust stack 38. The blower 30 is provided in the middle of the exhaust gas recirculation path 42. Further, in the middle of the exhaust gas recirculation path 42, a damper 44 as an opening / closing valve operated by a motor 46 is provided on the exhaust system side of the blower 30.

Thus, as shown in FIG. 2, the opening degree θa of the damper 44 is set when the solenoid valves 16 and 18 are both open, and the opening degree θb is set when only the solenoid valve 16 is opened. By interlocking the solenoid valves 16 and 18 and the damper 44, the supply amounts of fuel gas and exhaust gas can be adjusted.

Therefore, as shown in FIG. 3, the NOx value does not change even when the combustion amount is changed, and the NOx value can be set to an arbitrary value. Moreover, since it is only necessary to change the damper opening according to the number of open solenoid valves, it is possible to control with an extremely simple structure.

In this embodiment, as shown in FIG. 4, the damper 44 is attached to a shaft 50 that is operated by a motor 46, and the shaft 50 has three cams 52, 54, Reference numerals 56 and 56 are respectively attached by means of setscrews 58 by shifting the protrusions in accordance with the opening degrees θ ₁ , θ ₂ and θ ₃ of the damper 44. Micro switches 60, 62, 64 are provided corresponding to the cams 52, 54, 56 so that the opening of the damper can be known when the micro switch is turned off by the rotation of the cam. In the present embodiment, since the burner switches between four positions of OFF-LOW-HIGH-H.HEAT, the damper 44 is opened corresponding to the combustion amount of 50,000, 100,000 and 150,000 kcal, respectively. Determine the degrees θ ₁ , θ ₂ , and θ ₃ .

[0012]

[Effect of device]

 As described above, according to the present invention, it is possible to set the NOx value, which has changed depending on the combustion amount, to an arbitrary NOx value, without changing according to the combustion amount, with an extremely simple structure.

[Submission date] July 6, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

In this embodiment, as shown in FIG. 4, the damper 44 is attached to a shaft 50 that is operated by a motor 46, and the shaft 50 has three cams 52, 54, Reference numerals 56 and 56 are respectively attached by means of setscrews 58 by shifting the protrusions in accordance with the opening degrees θ ₁ , θ ₂ and θ ₃ of the damper 44. Micro switches 60, 62, 64 are provided corresponding to the cams 52, 54, 56 so that the opening of the damper can be known when the micro switch is operated by the rotation of the cam. In this embodiment, since the burner is switched between four positions of OFF-LOW-HIGH-H.HEAT, the damper 44 is operated in response to combustion amounts of 50,000, 100,000 and 150,000 kcal, respectively. Determine the opening θ ₁ , θ ₂ , θ ₃ .

[Brief description of drawings]

FIG. 1 is a configuration diagram of a system to which an embodiment of the present invention is applied.

FIG. 2 is a configuration diagram of a portion A in FIG.

FIG. 3 is a diagram for explaining the effect of the present embodiment.

FIG. 4 is a perspective view showing a partial structure of this embodiment.

FIG. 5 is a block diagram of a conventional system.

FIG. 6 is a diagram for explaining the operation in the conventional example.

[Explanation of symbols]

 10 burner 12 combustion chamber 14 fuel gas supply pipe 15a, 15b branch pipe 16, 18 solenoid valve 20 fuel gas 22, 24, 26, 28 air inlet 30 blower 32 combustion air 34 combustion flame 36 exhaust gas 38 exhaust stack 40 exhaust top 42 Exhaust Gas Recirculation Channel 44 Damper 46 Motor 50 Shaft 52, 54, 56 Cam 58 Set Screw 60, 62, 64 Micro Switch 80 Burner 81 Combustion Chamber 82 Fuel Gas 83 Fuel Gas Supply Pipe 84 Exhaust Gas Circulation Pipe 85 Blower 85 86 Combustion air 87, 88, 89 Air port 91 Exhaust gas 92 Exhaust stack 93 Exhaust top 94 Damper 95, 96 Solenoid valve θa, θb Damper opening

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[Procedure amendment]

[Submission date] July 6, 1993

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] Explanation of code

[Correction method] Change

[Correction content]

[Explanation of Codes] 10 Burner 12 Combustion Chamber 14 Fuel Gas Supply Pipe 15a, 15b Branch Pipe 16, 18 Solenoid Valve 20 Fuel Gas 22 Flame Port 24, 26, 28 Air Port 30 Blower 32 Combustion Air 34 Combustion Flame 36 Exhaust Gas 38 Exhaust stack 40 Exhaust top 42 Exhaust gas recirculation path 44 Damper 46 Motor 50 Shaft 52, 54, 56 Cam 58 Set screw 60, 62, 64 Micro switch 80 Burner 81 Combustion chamber 82 Fuel gas 83 Fuel gas supply pipe 84 Exhaust gas Circulation pipe 85 Blower 86 Combustion air 87,88,89 Air inlet 91 Exhaust gas 92 Exhaust stack 93 Exhaust top 94 Damper 95,96 Solenoid valve θa, θb Damper opening

Claims (1)

[Scope of utility model registration request] 1. Combustion air and fuel gas are supplied to a burner to mix them, and the mixture is injected from a burner into a combustion chamber for combustion, and exhaust gas due to combustion is discharged to an exhaust system. An exhaust gas recirculation control device for a burner, which comprises an exhaust gas recirculation path for returning a part of exhaust gas to a burner, and a blower is arranged in the middle of the exhaust gas recirculation path, wherein the exhaust gas is discharged from the blower in the exhaust gas recirculation path. Exhaust gas supplied to the combustion chamber by interlocking the opening degree of the on-off valve provided on the system side with the opening and closing amount of a plurality of solenoid valves provided in parallel in the middle of the pipeline of the fuel gas supply pipe to the burner. And an exhaust gas recirculation control device for a burner, which controls the supply amount of combustion gas.