JP2019109000A - Burner and combustion device - Google Patents

Abstract

To provide a burner and a combustion device using liquid fuel of a lower boiling point than that of kerosine, capable of safely carrying out transition from low combustion to high combustion.SOLUTION: A burner 20 comprising a first nozzle 21 that ejects liquid fuel of a lower boiling point than that of kerosine, a first pump 63 that delivers liquid fuel of a lower boiling point than that of kerosine to the first nozzle 21, a first fuel feed valve 65 disposed between the first pump 63 and the first nozzle 21, a second nozzle 22 that ejects liquid fuel of a lower boiling point than that of kerosine, a second pump 66 that delivers liquid fuel of a lower boiling point than that of kerosine to the second nozzle 22, a second fuel feed valve 68 disposed between the second pump 66 and the second nozzle 22, is controlled so as to increase a combustion amount upon carrying out the transition from low combustion to high combustion, by allowing the second nozzle 22 to eject liquid fuel while keeping the first nozzle 21 in a state of continuing to eject liquid fuel.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a burner and a combustion apparatus.

  A burner is conventionally known that includes a nozzle for injecting fuel, a pump for discharging fuel toward the nozzle, and a solenoid valve for fuel supply disposed between the pump and the nozzle. Among such burners, there is a burner that is provided in a boiler (combustion device) and increases the amount of fuel injected from the nozzle when transitioning from low combustion to high combustion. Some pumps of such burners have a mechanism for making the discharge pressure for discharging the fuel constant at the time of high combustion and low combustion.

  When it is intended to increase the fuel supply flow rate when transitioning from low combustion to high combustion using a pump having a mechanism for making the discharge pressure constant, discharge of the pump due to the influence of the opening / closing operation of the solenoid valve etc. A response delay (operation delay) of the pressure mechanism may occur, and the fuel supply flow rate may temporarily decrease. In this case, the ratio of the combustion air in the mixture ratio (air ratio) of the fuel and the combustion air may temporarily increase, and the combustion may be performed with the ratio of the combustion air being high.

  Here, as a burner, one using a highly volatile liquid fuel (liquid fuel having a boiling point lower than that of kerosene) such as alcohol is known (see, for example, Patent Document 1). Also in the burner described in Patent Document 1, there may be a response delay (operation delay) of the discharge pressure mechanism of the pump for the same reason as described above. In addition, in the burner using a highly volatile liquid fuel, the liquid fuel in the nozzle (between the fuel supply solenoid valve and the nozzle tip) may be volatilized.

JP, 2010-255932, A

  In burners that use highly volatile liquid fuel, in addition to the response delay (operation delay) of the discharge pressure mechanism of the pump, the liquid fuel is vaporized and lost, so the drop in the liquid fuel supply flow rate becomes remarkable The possibility of combustion with a high proportion of combustion air is higher.

  In addition, when using highly volatile liquid fuel, the liquid fuel in the nozzle (between the solenoid valve for fuel supply and the nozzle tip) is vaporized and lost, thereby transitioning from low combustion to high combustion. In some cases, the flame of the burner may go out. In this case, the liquid fuel is continuously injected from the nozzle into the combustion chamber of the heated boiler (combustion device) from the time when the flame of the burner is extinguished to the time of the misfire determination. As a result, the highly volatile liquid fuel may be vaporized to cause explosive combustion.

  An object of the present invention is to provide a burner and a combustion apparatus which can safely shift from low combustion to high combustion in a burner using a liquid fuel having a boiling point lower than that of kerosene.

  The present invention comprises a first nozzle for injecting a liquid fuel having a boiling point lower than that of kerosene, a first pump for discharging a liquid fuel having a boiling point lower than that of kerosene toward the first nozzle, the first pump, and the first pump A first fuel supply valve disposed between the first and second nozzles, a second nozzle for injecting a liquid fuel having a boiling point lower than that of kerosene, and a liquid fuel having a boiling point lower than that of kerosene are discharged toward the second nozzle A second pump, and a second fuel supply valve disposed between the second pump and the second nozzle, and when transitioning from low combustion to high combustion, the first nozzle is a liquid fuel The present invention relates to a burner controlled to increase the amount of combustion when the second nozzle injects liquid fuel while continuing injection.

  The present invention also includes the burner, a blower for supplying combustion air to a combustion chamber, a combustion air supply line for supplying combustion air blown by the blower to the combustion chamber, and the combustion air supply. An air amount adjustment unit arranged in a line to adjust the amount of combustion air, and when the first nozzle continues to inject liquid fuel when transitioning from low combustion to high combustion, the second nozzle is a liquid fuel And a combustion control unit that performs control to increase the combustion amount by performing injection, and the combustion control unit increases the combustion air with a predetermined time delay after injecting the liquid fuel from the second nozzle. The present invention relates to a combustion apparatus that controls the air amount adjustment unit so that

  According to the present invention, it is possible to provide a burner and a combustion apparatus which can safely shift from low combustion to high combustion in a burner using a liquid fuel having a boiling point lower than that of kerosene.

It is a figure showing a burner provided with a burner of one embodiment of the present invention.

  Hereinafter, an embodiment of a combustion apparatus 1 including a burner according to the present invention will be described with reference to the drawings. The combustion apparatus 1 includes, as shown in FIG. 1, a can 10, a burner 20 (described later) for burning liquid fuel, a blower 30 for feeding combustion air to the can 10, a can 10 and a blower 30 (described later Air supply line 40 (combustion air supply line) (described later) through which combustion air flows, a damper 50 (air amount adjustment unit) (described later) disposed in the air supply duct 40, and air supply A fuel supply unit 60 for supplying a fuel liquid fuel to the duct 40 and a control unit 70 for controlling the combustion state of the combustion apparatus 1 are provided.

  As shown in FIG. 1, the can 10 is constructed by standing a plurality of water pipes 12 in a cylindrical shape between an upper header 13 and a lower header (not shown), and the inner side of these water pipe groups is a combustion chamber It is assumed that 15.

  The burner 20 is disposed above the center of the can 10. The burner 20 is provided to inject liquid fuel downward. The liquid fuel injected from the burner 20 is combusted inside the plurality of cylindrically arranged water pipes 12.

  The burner 20 burns liquid fuel, and has a first nozzle 21, a second nozzle 22, and a cylinder 25. The first nozzle 21 includes a first nozzle pipe 211 and a first nozzle tip 212 provided at the lower end thereof. The second nozzle 22 is configured to include a second nozzle pipe 221 and a second nozzle tip 222 provided at the lower end thereof.

  The first nozzle pipe 211 and the second nozzle pipe 221 respectively extend in the vertical direction, and are adjacently arranged in parallel. The first nozzle tip 212 and the second nozzle tip 222 are disposed adjacent to each other and provided at the same height.

  The first nozzle 21 sprays the liquid fuel supplied to the first nozzle pipe 211 downward from the first nozzle tip 212. The second nozzle 22 sprays the liquid fuel supplied to the second nozzle pipe 221 downward from the second nozzle tip 222. Liquid fuel is supplied to the first nozzle tip 212 and the second nozzle tip 222 from a fuel supply unit 60 described later.

  The combustion air flows through the cylinder 25. The cylinder 25 is formed in a concentric cylindrical shape and is constituted by an inner and outer double cylindrical body, and extends in the vertical direction. Inside the feed cylinder 25, a first nozzle pipe 211 and a second nozzle pipe 221 are provided along the axis of the feed cylinder 25. The first nozzle pipe 211 and the second nozzle pipe 221 are disposed to extend to the vicinity of the lower end portion of the lower opening of the cylinder 18.

  The can body 10 includes a combustion cylinder 26 provided below the feed cylinder 25 and a wind box 27 provided above the feed cylinder 25.

  The combustion cylinder 26 is connected to the lower end of the cylinder 25 and formed in a cylindrical shape surrounding the first nozzle tip 212 and the second nozzle tip 222, and opens downward.

  The wind box 27 supplies combustion air to the feed cylinder 25 at the top of the feed cylinder 25. Combustion air from a blower 30 (described later) is introduced into the wind box 27 via an air supply duct 40 (described later).

  An upstream side of the air supply duct 40 is connected to the blower 30 (described later), and a downstream side is connected to the wind box 27. The air supply duct 40 supplies combustion air blown by the blower 30 to the combustion chamber 15.

  The damper 50 is disposed in the air supply duct 40. The damper 50 rotates 90 degrees from the closed state in which the flow path of the combustion air in the air supply duct 40 is closed and the closed state, and the damper 50 opens the flow path of the combustion air in the air supply duct 40. It is rotatably arranged between the states and adjusts the air amount of the combustion air supplied to the combustion device 1 by the rotation angle.

  The blower 30 supplies combustion air to the combustion chamber 15. The combustion air from the blower 30 is supplied to the combustion chamber 15 as combustion air via the air supply duct 40, the wind box 27 and the feed cylinder 25. In this manner, when the liquid fuel is sprayed from the first nozzle 21 and the second nozzle 22 for combustion, a predetermined amount of combustion air adjusted by the damper 50 is supplied into the combustion chamber 15.

  The fuel supply unit 60 supplies liquid fuel to the first nozzle 21 and the second nozzle 22. The fuel supply unit 60 includes a liquid fuel supply source 61, an upstream fuel supply line L1, a first downstream fuel supply line L2, a second downstream fuel supply line L3, a first pump 63, and a first opening / closing operation. A valve 64, a first fuel supply valve 65, a second pump 66, a second on-off valve 67, and a second fuel supply valve 68 are provided.

  Liquid fuel is supplied from the liquid fuel supply source 61 to the first nozzle 21 and the second nozzle 22. The liquid fuel supplied from the liquid fuel supply source 61 is a fuel having a boiling point lower than that of kerosene. Liquid fuel is a fuel having a lower boiling point than kerosene, and thus is a highly volatile fuel. In the present embodiment, the liquid fuel supplied to the first nozzle 21 and the liquid fuel supplied to the second nozzle 22 are the same liquid fuel, and are supplied from the common liquid fuel supply source 61. The liquid fuel is a fuel that is more volatile than a standard fuel such as heavy oil, light oil or kerosene, and is, for example, an alcohol fuel such as ethanol.

  More specifically, the liquid fuel in the present embodiment corresponds to the first petroleums and alcohols in the fourth class of flammable liquids in the Fire Service Law. Examples of the first petroleum include gasoline, benzene, toluene and the like. Examples of alcohols include methanol, ethanol, propanol and the like. The liquid fuel also includes, for example, a mixture of an organic substance and an alcohol.

The upstream side fuel supply line L1 is connected to the liquid fuel supply source 61 on the upstream side, and is connected to the branch portion 62 on the downstream side.
The first downstream fuel supply line L2 and the second downstream fuel supply line L3 are branched at the branch portion 62 at the downstream end of the upstream fuel supply line L1 and arranged in parallel downstream from the branch portion 62 . The upstream side of the first downstream side fuel supply line L2 is connected to the branch portion 62, and the downstream side is connected to the first nozzle 21. The upstream side of the second downstream side fuel supply line L3 is connected to the branch portion 62, and the downstream side is connected to the second nozzle 22.

  A first pump 63, a first on-off valve 64, and a first fuel supply valve 65 are provided in order from the branch portion 62 toward the first nozzle 21 in the first downstream side fuel supply line L2.

The first pump 63 is disposed upstream of the first downstream side fuel supply line L 2, and discharges the liquid fuel supplied from the liquid fuel supply source 61 toward the first nozzle 21.
The first on-off valve 64 and the first fuel supply valve 65 are constituted by solenoid valves, and the flow path of the first downstream side fuel supply line L2 is opened or doubled between the first pump 63 and the first nozzle 21. Cut off. When the liquid fuel is supplied to the first nozzle 21 via the first downstream fuel supply line L2, both the first on-off valve 64 and the first fuel supply valve 65 are maintained in the open state.

  A second pump 66, a second on-off valve 67, and a second fuel supply valve 68 are provided in order from the branch portion 62 to the second nozzle 22 in the second downstream side fuel supply line L3.

The second pump 66 is disposed on the upstream side of the second downstream side fuel supply line L 3, and discharges the liquid fuel supplied from the liquid fuel supply source 61 toward the second nozzle 22.
The second on-off valve 67 and the second fuel supply valve 68 are constituted by solenoid valves, and the flow path of the second downstream side fuel supply line L3 is opened or doubled between the second pump 66 and the second nozzle 22. Cut off. When the liquid fuel is supplied to the second nozzle 22 via the second downstream fuel supply line L3, both the second on-off valve 67 and the second fuel supply valve 68 are maintained in the open state.

  The control unit 70 controls the amount of combustion air supplied to the can 10 and the amount of liquid fuel supplied to control the combustion state (combustion rate) of the combustion device 1, and the amount of steam generated by the combustion device 1. Adjust the More specifically, the control unit 70 includes a combustion control unit 71. The combustion control unit 71 changes the combustion state of the combustion device 1 according to the consumption of steam by the load device to which the combustion device 1 supplies steam, and adjusts the amount of steam generation.

  The combustion apparatus 1 according to the present embodiment is a step value control boiler (3-position control boiler) capable of changing the combustion rate stepwise in three stages of combustion position of combustion stop position, low combustion position and high combustion position. Configured The control of the amount of combustion can be performed by steam pressure control, monitoring the working load of steam, for example, based on the steam pressure of a steam header (not shown).

  Further, the combustion control unit 71 operates / stops the first pump 63 and the second pump 66 according to the combustion state, and also the first on-off valve 64 and the first fuel supply valve 65, and the second on-off valve. 67 and the second fuel supply valve 68 are opened and closed to control the flow rate of the liquid fuel supplied to the burner 20. When the combustion device 1 is to be burned at the low combustion position, the first on-off valve 64 and the first fuel supply valve 65 are opened, and the second on-off valve 67 and the second fuel supply valve 68 are closed. 63 is operated, or the first on-off valve 64 and the first fuel supply valve 65 are closed, the second on-off valve 67 and the second fuel supply valve 68 are opened, and the second pump 66 is operated. When the combustion device 1 is burned at the high combustion position, the first on-off valve 64 and the first fuel supply valve 65 are opened, the second on-off valve 67 and the second fuel supply valve 68 are opened, and the first pump 63 and the second pump 66 are operated. When the combustion control unit 71 shifts from low combustion to high combustion, the on-off valve (the first on-off valve 64 or the second on-off valve) stops supplying the liquid fuel while maintaining the low combustion state. Valve 67) and the fuel supply valve (the first fuel supply valve 65 or the second fuel supply valve 68) are operated and the fuel pump (the first pump 63, the second pump 66) is operated to operate the nozzle (the first nozzle 21, The fuel amount is controlled to be increased by injecting the liquid fuel from the second nozzle 22).

  The combustion control unit 71 changes the opening degree of the damper 50 according to each combustion position to control the flow rate of the combustion air supplied to the combustion chamber 15. In the present embodiment, the combustion control unit 71 controls the opening degree of the damper 50 so as to increase the combustion air with a predetermined time delay after the liquid fuel is injected from the second nozzle 22. The delay time of the predetermined time for increasing the combustion air is preset by an experiment or the like.

In the combustion apparatus 1 configured as described above, an operation in the case of shifting from the low combustion state to the high combustion state will be described.
First, when operating the combustion apparatus 1 in the low combustion state based on the steam pressure of the steam header (not shown), the first on-off valve 64 and the first fuel supply valve are used to burn at the low combustion position. While opening 65, the second on-off valve 67 and the second fuel supply valve 68 are closed and the first pump 63 is controlled to operate. Thereby, the liquid fuel is burned in the combustion chamber 15 in a state where the liquid fuel is sprayed only from the first nozzle 21 without the liquid fuel being sprayed from the second nozzle 22.

  In the low combustion state, the blower 30 supplies the combustion air adjusted to the amount of air supplied in the low combustion state to the combustion chamber 15. The combustion air supplied by the blower 30 is mixed with the liquid fuel injected from the first nozzle 21 and burned. And the water supplied to the inside of the plurality of water tubes 12 from the lower header (not shown) is heated by the heat generated by the combustion, and the steam is generated. The steam generated inside the plurality of water tubes 12 is collected in the upper header 13 and then discharged to the outside through a steam outlet pipe (not shown).

  Thereafter, when transitioning from the low combustion state to the high combustion state, the first on-off valve 64 and the first fuel supply valve 65 are opened and the first pump 63 is operated in order to burn at the high combustion position. While continuing, the second on-off valve 67 and the second fuel supply valve 68 are opened, and the second pump 66 is controlled to operate. Thereby, the liquid fuel is burned in the combustion chamber 15 in a state where the liquid fuel is sprayed from the second nozzle 22 in addition to the first nozzle 21.

Conventionally, when it is attempted to increase the fuel supply flow rate when transitioning from low combustion to high combustion using a pump having a mechanism for making the discharge pressure constant, the pump is affected by the opening / closing operation of the solenoid valve, etc. The response delay (operation delay) of the discharge pressure mechanism occurs, and the fuel supply flow rate may temporarily decrease. In this case, the ratio of the combustion air in the mixture ratio (air ratio) of the fuel and the combustion air temporarily increases, and there is a possibility that combustion occurs with the ratio of the combustion air being high.
Also, when using a liquid fuel having a boiling point lower than that of kerosene such as alcohol (liquid fuel with high volatility) as the fuel to be supplied to the burner, the burner has a response delay (operation delay) of the discharge pressure mechanism of the pump. In addition, since the liquid fuel is vaporized and lost, the decrease in the supply flow rate of the liquid fuel becomes remarkable, and the possibility of combustion with a high proportion of combustion air is higher.
In addition, when using highly volatile liquid fuel, the liquid fuel in the nozzle (between the solenoid valve for fuel supply and the nozzle tip) is vaporized and lost, thereby transitioning from low combustion to high combustion. In some cases, the flame of the burner may go out. In this case, the liquid fuel is continuously injected from the nozzle into the combustion chamber of the heated boiler (combustion device) from the time when the flame of the burner is extinguished to the time of the misfire determination. Thereby, there is a possibility that explosive combustion may occur due to the vaporization of the highly volatile liquid fuel.

  On the other hand, in the present invention, when transitioning from low combustion to high combustion, the second pump 66 continues with the operation of the first pump 63 being continued and the first nozzle 21 injecting liquid fuel. The second nozzle 22 injects the liquid fuel by starting the operation of (4) to control to increase the amount of combustion. As a result, at the time of transition from low combustion to high combustion, the first pump 63 always maintains a constant discharge amount, and an operation delay of the first pump 63 does not occur. In addition, the second pump 66 starts operation while the first pump 63 is operating, whereby the liquid fuel in the second nozzle 22 (between the second fuel supply valve 68 and the second nozzle tip 222) Since the fuel is injected from the first nozzle 21 even if the fuel is vaporized and lost, the misfire can be suppressed. Therefore, the transition from low combustion to high combustion can be performed safely.

  Here, with the transition of the combustion amount from low combustion to high combustion, the air amount of the combustion air supplied from the blower 30 to the combustion chamber 15 is adjusted. In the present embodiment, the opening degree of the damper 50 is controlled to increase the combustion air with a predetermined time delay after the liquid fuel is injected from the second nozzle 22. As a result, when transitioning from low combustion to high combustion, even if the supply of liquid fuel from the second nozzle 22 is delayed, a rapid increase in the ratio of combustion air is suppressed. Therefore, the transition from low combustion to high combustion can be performed safely.

According to the burner 20 and the combustion apparatus 1 which concern on this embodiment mentioned above, the following effects are show | played, for example.
The burner 20 according to the present embodiment includes a first nozzle 21 for injecting liquid fuel having a boiling point lower than that of kerosene, a first pump 63 for discharging liquid fuel having a boiling point lower than that of kerosene toward the first nozzle 21, The first fuel supply valve 65 disposed between the first pump 63 and the first nozzle 21, the second nozzle 22 for injecting liquid fuel having a boiling point lower than that of kerosene, and the liquid fuel having a boiling point lower than that of kerosene 2) A second pump 66 discharging toward the two nozzles 22 and a second fuel supply valve 68 disposed between the second pump 66 and the second nozzle 22 when transitioning from low combustion to high combustion It is controlled to increase the amount of combustion by the second nozzle 22 injecting the liquid fuel while the first nozzle 21 continues the injection of the liquid fuel. As a result, at the time of transition from low combustion to high combustion, the first pump 63 always maintains a constant discharge amount, and an operation delay of the first pump 63 does not occur. In addition, the second pump 66 starts operation while the first pump 63 is operating, whereby the liquid fuel in the second nozzle 22 (between the second fuel supply valve 68 and the second nozzle tip 222) Since the fuel is injected from the first nozzle 21 even if the fuel is vaporized and lost, the misfire can be suppressed. Therefore, the transition from low combustion to high combustion can be performed safely.

  Further, the combustion apparatus 1 of the present embodiment includes a burner 20, a blower 30 for supplying combustion air to the combustion chamber 15, and an air supply duct 40 for supplying combustion air blown by the blower 30 to the combustion chamber 15. A damper 50 disposed in the air supply duct 40 for adjusting the amount of combustion air, and the second nozzle 22 is a liquid in a state where the first nozzle 21 continues the liquid fuel injection when transitioning from low combustion to high combustion And a combustion control unit 71 that performs control to increase the amount of combustion by performing injection of fuel, and the combustion control unit 71 is for combustion after a predetermined time delay from the injection of liquid fuel from the second nozzle 22. The damper 50 is controlled to increase air. As a result, the combustion air is increased with a predetermined time delay after the liquid fuel is injected from the second nozzle 22. Therefore, when transitioning from low combustion to high combustion, the ratio of the combustion air is abrupt or excessive. It is suppressed to increase. Therefore, the transition from low combustion to high combustion can be performed safely.

Hereinabove, the preferred embodiments of the present invention have been described. However, the present invention can be implemented in various forms without being limited to the above-described embodiment.
For example, in the above embodiment, when combustion is performed with low combustion, only the first fuel supply valve 65 is opened, and when transitioning from low combustion to high combustion, the second fuel supply valve 65 is opened in the second state. Although the fuel supply valve 68 is controlled to open, it is not limited thereto. That is, the control for opening the first fuel supply valve 65 and the second fuel supply valve 68 may be reversed, and in the case of low combustion, only the second fuel supply valve 68 is opened and low combustion to high combustion is performed. At the time of transition to the above, the first fuel supply valve 65 may be controlled to be opened with the second fuel supply valve 68 open.

  In the above embodiment, the fuel supply valves (the first fuel supply valve 65 and the second fuel supply valve 68) are solenoid valves. However, the present invention is not limited to this. A motor valve or the like may be used. A valve may be used.

  Moreover, in the said embodiment, although the combustion apparatus 1 of this invention was applied to the boiler of 3 position control, it does not restrict to this. That is, the combustion apparatus 1 of the present invention may be applied to a four-position control or higher boiler having a plurality of middle combustion positions or a boiler for continuous combustion control.

DESCRIPTION OF SYMBOLS 1 combustion apparatus 15 combustion chamber 20 burner 21 1st nozzle 22 2nd nozzle 30 air blower 40 air supply duct (air supply line for combustion)
50 Damper (air amount adjustment unit)
63 first pump 65 first fuel supply valve 66 second pump 68 second fuel supply valve 71 combustion control unit

Claims (2)

A first nozzle for injecting liquid fuel having a boiling point lower than that of kerosene;
A first pump for discharging toward the first nozzle a liquid fuel having a boiling point lower than that of kerosene;
A first fuel supply valve disposed between the first pump and the first nozzle;
A second nozzle for injecting liquid fuel having a boiling point lower than that of kerosene,
A second pump for discharging toward the second nozzle a liquid fuel having a boiling point lower than that of kerosene;
A second fuel supply valve disposed between the second pump and the second nozzle;
A burner controlled to increase the amount of combustion when the second nozzle injects liquid fuel while the first nozzle continues to inject liquid fuel when transitioning from low combustion to high combustion. . A burner according to claim 1;
A blower for supplying combustion air to the combustion chamber;
A combustion air supply line for supplying combustion air blown by the blower to the combustion chamber;
An air amount adjustment unit disposed in the combustion air supply line to adjust the amount of combustion air;
A combustion control unit configured to increase the amount of combustion by injecting the liquid fuel while the first nozzle continues to inject liquid fuel when shifting from low combustion to high combustion. And
The combustion control unit controls the air amount adjustment unit so as to increase combustion air with a predetermined time delay after injecting the liquid fuel from the second nozzle.

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