JP2002005412A - Waste gas re-combustion type combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste gas re-combustion type combustion device capable of contriving cost down and the improvement of a thermal efficiency while switching freely from a normal combustion condition, burning fuel employing the waste gas of a prime mover, into a temporary combustion condition wherein the fuel is burnt by only air. SOLUTION: The combustion device is provided with a combustion control means FC which supplies the waste gas of the prime mover or air from a ventilating means 1 into a combustion chamber 51 through a main oxygen containing gas supplying port 5 and supplies the waste gas of prime mover into the combustion chamber 51 through an auxiliary oxygen containing gas supplying port 7 to effect the ordinary combustion wherein the fuel from a burner main body 4 is burnt. In such a combustion device, the combustion control means FC is constituted so as to be capable of freely switching the ordinary combustion into the temporary combustion condition wherein the fuel from the burner main body 4 is burnt while supplying air, sufficient for burning the total amount of fuel from the burner main body 4, into the combustion chamber 51 through the main oxygen containing gas supplying port 5 and supplying heat receiving waste gas after passing through a heating unit R into the combustion chamber 51 through the auxiliary oxygen containing gas supplying port 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply burner main body which is disposed facing a combustion chamber for heating a heated portion,
A burner including a main oxygen-containing gas supply port disposed around the burner main body and an auxiliary oxygen-containing gas supply port disposed farther from the burner main body than the main oxygen-containing gas supply port is provided, and A motor exhaust gas discharged from a prime mover or air from a blowing means is supplied into the combustion chamber from the main oxygen-containing gas supply port, and the motor exhaust gas is supplied into the combustion chamber from the auxiliary oxygen-containing gas supply port. The present invention also relates to an exhaust gas reburning type combustion device provided with combustion control means for performing normal combustion for burning fuel from the burner body.

[0002]

2. Description of the Related Art An exhaust gas reburning type combustion device (hereinafter sometimes simply referred to as a combustion device) burns fuel by using exhaust gas of a prime mover from a gas turbine or the like as a combustion type prime mover. The exhaust gas of the prime mover is additionally fired, and the exhaust heat boiler or the like as a heated portion is heated by the exhaust gas of the prime mover motor.

[0003] Incidentally, if the oxygen content in the exhaust gas of the prime mover to be received is, for example, about 10 to 18% (weight percentage, hereinafter the same), the fuel from the burner body can be burned only with the prime mover exhaust gas. Therefore, the combustion control means is configured to supply the engine exhaust gas into the combustion chamber from both the main oxygen-containing gas supply port and the auxiliary oxygen-containing gas supply port to perform normal combustion for burning the fuel from the burner body. It is. Further, when the oxygen content in the exhaust gas of the prime mover to be received is smaller than, for example, 10%, it is difficult to stably burn the fuel from the burner body only with the prime mover exhaust gas. The air is supplied into the combustion chamber from the supply port, and the exhaust gas of the motor is supplied into the combustion chamber from the auxiliary oxygen-containing gas supply port to perform normal combustion for burning the fuel from the burner body.

[0004] In the case of performing normal combustion only with the exhaust gas of a motor,
In any case where the normal combustion is performed using the exhaust gas from the motor and the air, the supply amount of the exhaust gas or the air from the main oxygen-containing gas supply port is an amount necessary to burn all the fuel from the burner body. Less than the amount that can supply oxygen, the shortage of oxygen for combustion is
The so-called slow combustion is performed to compensate for the exhaust gas from the motor from the auxiliary oxygen-containing gas supply port, thereby lowering the flame temperature and suppressing the generation of NOx. In addition, when normal combustion is performed using exhaust gas from a motor and air, the amount of air supplied is reduced as much as possible, and the heat efficiency is improved by suppressing the exhaust loss.

It is desirable to receive the entire amount of the motor exhaust gas generated by the combustion device, while the heating load of the heated portion may fluctuate. In such a case, while adjusting the heating load to adjust the fuel supply amount from the burner main body while accepting the entire amount of the generated exhaust gas, the oxygen-containing gas for burning the fuel from the burner main body is used. Since the gas is supplied separately from the main oxygen-containing gas supply port and the auxiliary oxygen-containing gas supply port, stable combustion can be performed even if the heating load is reduced and the fuel supply amount is reduced.

When the motor is stopped for inspection or failure, the supply of the engine exhaust gas is stopped.
If it is necessary to continue heating the heated portion even during the stoppage of the supply of the motor exhaust gas, it is necessary to burn the fuel from the burner body only with air.

Therefore, in the conventional combustion apparatus, the combustion control means supplies sufficient air for burning the entire amount of fuel from the burner body into the combustion chamber from the main oxygen-containing gas supply port, and supplements air at room temperature. The combustion chamber was configured to be supplied to the combustion chamber through the oxygen-containing gas supply port so as to be able to switch to a temporary combustion state in which fuel from the burner body was burned. By the way, the normal-temperature air is supplied into the combustion chamber from the auxiliary oxygen-containing gas supply port because the gas in the high-temperature combustion chamber (hereinafter sometimes referred to as combustion chamber air) is supplied from the auxiliary oxygen-containing gas supply port into the burner. This is to prevent the burner component constituting the burner from burning backward due to backflow.

[0008]

Therefore, conventionally, in the temporary combustion state, normal-temperature air is supplied into the combustion chamber from the auxiliary oxygen-containing gas supply port, so that the temperature of the combustion chamber air decreases. However, there is a problem that the exhaust loss increases and the thermal efficiency decreases. Instead of supplying normal-temperature air into the combustion chamber from the auxiliary oxygen-containing gas supply port to prevent the backflow of air in the combustion chamber, the combustion from the auxiliary oxygen-containing gas supply port is performed by using a high heat-resistant material as a burner component. There may be cases where the backflow of room air is allowed. However, since an expensive high heat-resistant material is used as a burner constituent material, the price of the combustion device increases, and it is not practical.

The present invention has been made in view of the above circumstances, and an object thereof is to freely switch between a normal combustion state in which fuel is burned using engine exhaust gas and a temporary combustion state in which fuel is burned only with air. Accordingly, it is an object of the present invention to provide an exhaust gas reburning type combustion device capable of reducing the price and improving the thermal efficiency.

[0010]

Means for Solving the Problems [Invention according to claim 1]
According to a characteristic configuration of the present invention, the combustion control means supplies sufficient air to burn the entire amount of fuel from the burner main body into the combustion chamber from the main oxygen-containing gas supply port, and The deheated exhaust gas after passing through the heating unit is supplied from the auxiliary oxygen-containing gas supply port into the combustion chamber, and is configured to be freely switchable to a temporary combustion state in which fuel from the burner body is burned. . According to the characteristic configuration of the first aspect, in the temporary combustion state, air sufficient to burn the entire amount of fuel from the burner body is supplied from the main oxygen-containing gas supply port into the combustion chamber, and the heated portion is heated. Is passed through the auxiliary oxygen-containing gas supply port into the combustion chamber, and the fuel from the burner body burns. Then, the deheated exhaust gas whose temperature has decreased after passing through the heated portion is supplied into the combustion chamber from the auxiliary oxygen-containing gas supply port, so that high-temperature combustion chamber air enters the burner from the auxiliary oxygen-containing gas supply port. Since the backflow is prevented, burnout of the burner component can be prevented without using a high heat-resistant material for the burner component. Moreover, although heat is applied to the heated portion and the temperature is lowered, the deheated exhaust gas having a higher temperature than the normal temperature air is supplied into the combustion chamber from the auxiliary oxygen-containing gas supply port. Compared to a case where air at a normal temperature is supplied, a decrease in the temperature of the air in the combustion chamber can be suppressed, and the exhaust loss can be reduced. Therefore, an exhaust gas reburning system capable of reducing costs and improving thermal efficiency while enabling switching between a normal combustion state in which fuel is burned using engine exhaust gas and an extraordinary combustion state in which fuel is burned only with air. Can be provided.

According to a second aspect of the present invention, the burner includes a fuel introduction pipe communicating with the burner main body and a main oxygen-containing gas introduction communicating with the main oxygen-containing gas supply port. A burner unit provided with a passage and an auxiliary oxygen-containing gas introduction passage communicating with the auxiliary oxygen-containing gas supply port, and for the burner unit, a fuel supply pipe for supplying fuel, the blowing means, and the motor A motor exhaust gas supply path to which motor exhaust gas is supplied from, and a deheated exhaust gas reduction path that guides the deheated exhaust gas after passing through the heated portion to be supplied from the auxiliary oxygen-containing gas supply port into the combustion chamber, respectively. Being connected. According to the characteristic configuration of claim 2, the burner communicates with the fuel introduction pipe communicating with the burner main body, the main oxygen-containing gas introduction passage communicating with the main oxygen-containing gas supply port, and the auxiliary oxygen-containing gas supply port. The burner unit is provided with an auxiliary oxygen-containing gas introduction passage, and the burner unit can be attached to the combustion chamber. Therefore, the burner main body and the main oxygen-containing gas need to be arranged in a predetermined positional relationship. The supply port and the auxiliary oxygen-containing gas supply port can be easily arranged in an appropriate state. In addition, a fuel supply pipe for supplying fuel, a blower, a motor exhaust gas supply passage through which engine exhaust gas is supplied from the engine, and a deheated exhaust gas after passing through the heated portion are supplied from the auxiliary oxygen-containing gas supply port to the combustion chamber. Can be connected to the burner unit, so that the operation is simple. On the other hand, when the burner body, the main oxygen-containing gas supply port, and the auxiliary oxygen-containing gas supply port are each configured separately, the separate burner body, main oxygen-containing gas supply port, and auxiliary oxygen-containing gas are separately provided. The operation of arranging the supply ports in a predetermined positional relationship with respect to the combustion chamber becomes complicated. Further, a fuel supply pipe for the burner main body, an air supply path from the air supply means and a motor exhaust gas supply path for the main oxygen-containing gas supply port, and a motor exhaust gas supply path for the auxiliary oxygen-containing gas supply port and Since it is necessary to directly connect each of the deheated exhaust gas reduction paths, the operation is also complicated. Therefore, while making it possible to switch between the normal combustion state and the temporary combustion state,
It is possible to provide a preferred specific configuration for simplifying the installation configuration of the combustion device.

According to a third aspect of the present invention, there is provided a fuel cell system according to the third aspect, wherein the heated portion is configured such that the main heat exchanger of the exhaust heat boiler and the deheated exhaust gas passing through the main heat exchanger pass therethrough. And a feedwater preheating heat exchanger for preheating water supplied to the main heat exchanger, wherein the combustion control means passes through the feedwater preheating heat exchanger. Is supplied from the auxiliary oxygen-containing gas supply port into the combustion chamber. Claim 3
According to the characteristic configuration described in the above, in the temporary combustion state,
After passing through the main heat exchanger, and further passing through the feedwater preheating heat exchanger located downstream of the main heat exchanger, the deheated exhaust gas having a further lowered temperature is supplied to the auxiliary oxygen-containing gas supply port. And supplied into the combustion chamber. Therefore, when the present invention is applied to a combustion device for heating a waste heat boiler, in particular, for the purpose of preventing backflow of air in a combustion chamber, the heat is further reduced after passing through a heat exchanger for preheating a feedwater. The use of the exhaust gas is preferable because the heat-resistant specification of the component for guiding the deheated exhaust gas to the auxiliary oxygen-containing gas supply port can be set low, and the implementation cost can be reduced.

The invention according to claim 4 is characterized in that a backflow detecting means for detecting in advance that the gas in the combustion chamber flows back to the auxiliary oxygen-containing gas supply port is provided, The combustion control means is configured to be capable of adjusting a reduction amount of the deheated exhaust gas reduced into the combustion chamber from the auxiliary oxygen-containing gas supply port, and based on detection information of the backflow detection means, In order to prevent the gas in the combustion chamber from flowing back to the auxiliary oxygen-containing gas supply port,
The configuration is such that the amount of reduction of the deheated exhaust gas is adjusted. According to the characteristic configuration of the fourth aspect, in the temporary combustion state, the heat removal is performed based on the detection information of the backflow detection means so as to prevent the air in the combustion chamber from flowing back to the auxiliary oxygen-containing gas supply port. The amount of exhaust gas reduction is automatically adjusted. Therefore, while enabling the switching between the normal combustion state and the temporary combustion state, the temporary combustion state can be automatically maintained in an appropriate state in which the backflow of the air in the combustion chamber can be prevented.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] An embodiment in which the present invention is applied to an exhaust gas reburning type combustion device used for heating an exhaust heat boiler in a cogeneration system will be described below. First, a first embodiment will be described with reference to FIGS. As shown in FIG. 1, the cogeneration system includes a gas turbine GT as a combustion type prime mover,
The fuel gas is burned using exhaust gas (corresponding to motor exhaust gas, and may be abbreviated as turbine exhaust gas hereinafter) from the generator EG and the gas turbine GT driven by the T, and the turbine exhaust gas is refired. Combustion device F according to the invention
S, and an exhaust heat boiler SB heated by the combustion device FS to obtain electric power from the generator EG, recover exhaust heat from turbine exhaust gas, and obtain steam from the exhaust heat boiler SB. It is configured in. In the first embodiment, the oxygen content of the turbine exhaust gas is about 10 to 18%, and in the burner B described later, the fuel gas can be burned only by the turbine exhaust gas. Further, the temperature of the turbine exhaust gas is about 500 ° C.

The gas turbine GT includes a compressor 42 for compressing air taken from an intake passage 41 and a combustor 44 for burning fuel gas supplied through a fuel gas supply passage 43 by the compressed air from the compressor 42. And a turbine section 45 driven by the combustion gas from the combustor 44. The turbine section 45 drives the generator EG and the compressor 42.

The exhaust heat boiler SB includes a boiler main body (main heat source) comprising a combustion chamber 51 and a number of water tubes arranged so that high-temperature (for example, 900 ° C. or higher) combustion chamber air in the combustion chamber 51 passes therethrough. And an economizer 55 (corresponding to a water supply preheating heat exchanger) disposed in an exhaust duct 54 for guiding the deheated exhaust gas after passing through the boiler main body 52 to a chimney 53. It is provided for.
Then, the high-temperature combustion chamber air in the combustion chamber 51 is passed through the boiler main body 52 and the economizer 55 in this order, and the water supplied through the water supply channel 56 is preheated by the economizer 55 and then flows through the boiler main body 52. Let it heat,
The generated steam is configured to be supplied to a steam destination (not shown) through a steam delivery path 57.

The combustion device FS will be described with reference to FIGS. The combustion device FS includes a burner B that burns fuel gas with turbine exhaust gas and air, a combustion blower 1 as a blower for supplying combustion air to the burner B, and a burner B that passes through a heated portion through the burner B. An exhaust gas reducing blower 2 for supplying the deheated exhaust gas, a burner control unit 3 for controlling various controls of the combustion device FS, and the like.

The burner B includes a combustion chamber 5 of the exhaust heat boiler SB.
1, a gas nozzle 4 serving as a burner body for supplying fuel, a primary oxygen-containing gas supply port 5 serving as a main oxygen-containing gas supply port disposed around the gas nozzle 4, and a primary oxygen-containing gas supply port Gas nozzle 4 than 5
Oxygen-containing gas supply port 6 that is arranged at a distance from the nozzle, and a gas nozzle 4 that is larger than the secondary oxygen-containing gas supply port 6
A tertiary oxygen-containing gas supply port 7 is provided as an auxiliary oxygen-containing gas supply port that is disposed away from the gas supply port.

A gas nozzle 4, a primary oxygen-containing gas supply port 5, a secondary oxygen-containing gas supply port 6, and a tertiary oxygen-containing gas supply port 7 are provided at the front of the box-shaped burner casing 8 (on the side of the exhaust heat boiler SB). Inside the burner casing 8, a fuel gas introduction pipe 9 communicating with the gas nozzle 4, a primary oxygen-containing gas introduction path 10 as a main oxygen-containing gas introduction path communicating with the primary oxygen-containing gas supply port 5, a secondary oxygen-containing gas Supply port 6
And a tertiary oxygen-containing gas introduction passage 12 serving as an auxiliary oxygen-containing gas introduction passage communicating with the tertiary oxygen-containing gas supply port 7, and after the burner casing 8. A turbine exhaust gas receiving portion 13 communicating with the starting end of each of the primary oxygen-containing gas introduction passage 10, the secondary oxygen-containing gas introduction passage 11, and the tertiary oxygen-containing gas introduction passage 12 is provided on the surface portion to form a burner unit BU. is there.

That is, the burner B is connected to the fuel gas introduction pipe 9 communicating with the gas nozzle 4, the primary oxygen-containing gas introduction passage 10 communicating with the primary oxygen-containing gas supply port 5, and the secondary gas containing the secondary oxygen-containing gas supply port 6. The burner unit BU includes a secondary oxygen-containing gas introduction path 11 and a tertiary oxygen-containing gas introduction path 12 communicating with the tertiary oxygen-containing gas supply port 7.

The primary oxygen-containing gas supply port 5 is formed in an annular shape, and the gas nozzle 4 is disposed at the center of the annular primary oxygen-containing gas supply port 5. Secondary oxygen-containing gas supply port 6
Is formed in an annular shape around the primary oxygen-containing gas supply port 5, and the tertiary oxygen-containing gas supply port 7 is formed in an annular shape around the secondary oxygen-containing gas supply port 6.

A secondary damper 15 for opening and closing the communicating portion with the turbine exhaust gas receiving portion 13 in the secondary oxygen-containing gas introducing passage 11 is provided, and a turbine exhaust gas receiving portion 13 in the tertiary oxygen containing gas introducing passage 12 is provided. A tertiary damper 16 that opens and closes the communication part is provided in the communication part with. The primary oxygen-containing gas supply port 5 is provided with a primary swirler 17, and the secondary oxygen-containing gas supply port 6 is provided with a secondary swirler 18.
Is provided.

A backflow detecting temperature sensor 19 is provided so as to detect the temperature in the tertiary oxygen-containing gas introduction passage 12. That is, when the high-temperature combustion chamber air flows into the tertiary oxygen-containing gas supply port 7 and flows backward, the tertiary oxygen-containing gas introduction path 1
2 rises, the backflow detecting temperature sensor 19
Based on the detected temperature, it is possible to detect in advance that the high-temperature combustion chamber air flows back to the tertiary oxygen-containing gas supply port 7. Therefore, the backflow detecting temperature sensor 19 is
It functions as backflow detecting means for detecting in advance that the combustion chamber air flows back to the tertiary oxygen-containing gas supply port 7.

Then, the burner unit BU having the above-described structure is mounted on the front surface of the combustion chamber 5 of the exhaust heat boiler SB.
The burner is mounted on the furnace wall of the combustion chamber 51 in a posture facing the burner mounting opening provided on the furnace wall of No. 1.

A turbine exhaust gas supply path 20 as a motor exhaust gas supply path to which turbine exhaust gas is supplied from the gas turbine GT to the turbine exhaust gas receiving section 13, and
A combustion air supply path 21 to which air is supplied from the combustion blower 1 is connected, a turbine exhaust gas supply path 20 is provided with a turbine exhaust gas damper 22, and a combustion air supply path 21 is provided with an air damper 23. I have. The combustion blower 1
By adjusting the rotation speed by the inverter control unit, the amount of air blown, that is, the supply amount of combustion air, can be adjusted. A fuel gas supply pipe 24 (corresponding to a fuel supply pipe) for supplying a fuel gas such as city gas is connected to the fuel gas introduction pipe 9, and the supply of the fuel gas to the fuel gas supply pipe 24 is interrupted. An on-off valve 25 and a proportional valve 26 for adjusting the fuel gas supply amount are provided.

A portion corresponding to a position between the boiler main body 52 and the economizer 55 in the exhaust duct 54 of the exhaust heat boiler SB, and the tertiary oxygen-containing gas introduction passage 1 of the burner unit BU.
A deheated exhaust gas returning path 27 is provided in a state of connecting with a portion corresponding to the downstream side of the tertiary damper 16 in 2. The exhaust gas reducing blower 2 is provided in the deheated exhaust gas returning passage 27 so as to suction the exhaust duct 54, and further, the deheated exhaust gas returning passage 27 has a deheated exhaust gas opening and closing passage. A damper 28 is interposed. And
Due to the ventilation action of the exhaust gas reduction blower 2, the boiler body 5
2, the deheated exhaust gas before passing through the economizer 55 is supplied from the tertiary oxygen-containing gas supply port 7 into the combustion chamber 51. That is, in the first embodiment, the boiler main body 52 corresponds to the heated portion R. The temperature of the deheated exhaust gas passing through the boiler main body 52 and before passing through the economizer 55 is about 300 ° C. If the deheated exhaust gas has such a temperature, the deheated exhaust gas return path 27 and the burner constituent material There is no need to use expensive high heat resistant materials.
The rotation speed of the exhaust gas reduction blower 2 can be freely adjusted by an inverter control unit. By adjusting the rotation speed of the exhaust gas reduction blower 2, the deheated exhaust gas is supplied from the tertiary oxygen-containing gas supply port 7 to the combustion chamber 51. It is configured to regulate the amount of reduction to be supplied to the inside and reduced.

Next, the control operation of the burner control section 3 will be described. The burner control unit 3 includes a turbine operation information that is output from a turbine control unit 46 that controls the gas turbine GT, turbine operation information indicating whether the gas turbine GT is operating, and a boiler that detects the heating load of the exhaust heat boiler SB by pressure. Pressure sensor 5
8 and the detection information of the backflow detecting temperature sensor 19 are respectively input. The burner control unit 3 includes an operation panel 29.
, Various control commands are input. The operation panel 29 includes:
A temporary combustion mode switching command switch for instructing switching from the normal combustion mode to the temporary combustion mode, and a normal combustion mode return command switch (not shown) for instructing a return from the temporary combustion mode to the normal combustion mode are provided. I have. Further, the burner control unit 3 sends the combustion blower 1,
Exhaust gas reduction blower 2, secondary damper 15, tertiary damper 1
6. Turbine exhaust gas damper 22, air damper 23,
A control signal for controlling operation of each of the deheated exhaust gas damper 28, the on-off valve 25, and the proportional valve 26 is output.

When the turbine operation signal indicating that the gas turbine GT is operating is output from the turbine control unit 46, the burner control unit 3, as shown in FIG. , Secondary damper 15
And the tertiary damper 16 is opened, the air damper 23 and the deheated exhaust gas damper 28 are closed, and the combustion blower 1 and the exhaust gas reduction blower 2 are stopped to supply the turbine exhaust gas with the primary oxygen-containing gas. A normal combustion mode in which fuel is supplied from the gas nozzle 4, the secondary oxygen-containing gas supply port 6, and the tertiary oxygen-containing gas supply port 7 into the combustion chamber 51 through the gas nozzle 4 is executed. In FIG. 2, the flow of the turbine exhaust gas is indicated by solid arrows.

When the signal from the turbine controller 46 switches from the turbine operation signal to a turbine stop signal indicating that the gas turbine GT has stopped, the burner controller 3
Is a turbine exhaust gas damper 22, as shown in FIG.
The secondary damper 15 and the tertiary damper 16 are closed, the air damper 23 and the deheated exhaust gas damper 28 are opened, and the combustion air blower 1 and the exhaust gas reduction air blower 2 are operated, so that the gas nozzle 4 Air sufficient to burn the entire amount of the fuel gas is supplied from the primary oxygen-containing gas supply port 5 to the combustion chamber 51, and the deheated exhaust gas after passing through the boiler main body 52 is supplied from the tertiary oxygen-containing gas supply port 7 to the combustion chamber. 51
And a temporary combustion mode in which the fuel gas from the gas nozzle 4 is burned. In FIG. 3, the flow of air is indicated by a dashed arrow, and the flow of deheated exhaust gas is indicated by a dashed-line arrow.

During the execution of the temporary combustion mode, the rotation speed of the exhaust gas reducing blower 2 is adjusted so that the detected temperature of the backflow detecting temperature sensor 19 is maintained within a set temperature range for backflow prevention. The set temperature range for backflow prevention is such that the rotation speed of the exhaust gas reduction blower 2 can be made as low as possible in a state where backflow of the combustion chamber air to the tertiary oxygen-containing gas supply port 7 can be prevented. Set the temperature range. Therefore, it is possible to automatically prevent the backflow of the combustion chamber air to the tertiary oxygen-containing gas supply port 7 while minimizing the power consumption of the exhaust gas reduction blower 2.

When the switch from the temporary combustion mode switching command switch of the operation panel 29 to the temporary combustion mode is commanded, the burner control unit 3 switches from the normal combustion mode to the temporary combustion mode, and returns to the normal combustion mode return command switch. When a command is issued to return to the normal combustion mode from the temporary combustion mode, the mode is switched from the temporary combustion mode to the normal combustion mode. Incidentally, when the gas turbine GT is stopped for maintenance or the like, the temporary combustion mode is switched to the temporary combustion mode by using the temporary combustion mode switching command switch. When the gas turbine GT changes from a stopped state to a normal operation state, the normal combustion mode is switched by the normal combustion mode return command switch.

In both the execution of the normal combustion mode and the execution of the extraordinary combustion mode, the burner controller 3 adjusts the proportional valve 26 so that the detected pressure of the boiler pressure sensor 58 becomes the set pressure. The combustion amount of the burner B is adjusted, and during the execution of the temporary combustion mode, the combustion blower 1 is controlled such that the combustion air amount becomes an amount corresponding to the combustion amount.

Therefore, the combustion control means FC is controlled by the burner control unit 3, the exhaust gas returning blower 2, the secondary damper 15, the tertiary damper 16, the turbine exhaust gas damper 22, the air damper 23, and the deheated exhaust gas damper 28. It is composed.

In the temporary combustion mode, nothing is supplied from the secondary oxygen-containing gas supply port 6 to the combustion chamber 51, but the secondary oxygen-containing gas connected to the secondary oxygen-containing gas supply port 6 is not supplied. The opening at the beginning of the introduction path 11 is the secondary damper 1
5 and the gas flows through the primary oxygen-containing gas introduction passage 10 and the tertiary oxygen-containing gas introduction passage 12 on both sides of the secondary oxygen-containing gas introduction passage 11, so that draft is prevented. Therefore, the combustion chamber air does not flow through the secondary oxygen-containing gas introduction passage 11. Further, even if the combustion chamber air flows into the secondary oxygen-containing gas introduction passage 11 from the secondary oxygen-containing gas supply port 6, there is no draft.
And the gas flows through the primary oxygen-containing gas introduction path 10 and the tertiary oxygen-containing gas introduction path 12 on both sides of the secondary oxygen-containing gas introduction path 11, so that the cooling action causes the burner unit BU to overheat. Never be.

Hereinafter, each of the second and third embodiments of the present invention will be described. However, for the same components and components having the same functions as those of the first embodiment, the same reference numerals are used to avoid redundant description. The description will be omitted by attaching them, and mainly the configuration different from the first embodiment will be described.

[Second Embodiment] A second embodiment will now be described with reference to FIGS. Also in the second embodiment, the oxygen content of the turbine exhaust gas is 10 to 1
In the burner B, the fuel gas can be burned only by the turbine exhaust gas. The burner unit BU is configured similarly to the above-described first embodiment except for the configuration described below. That is, a primary damper 14 that opens and closes the communication part is provided in a communication part of the primary oxygen-containing gas introduction path 10 with the turbine exhaust gas receiving part 13,
An air receiving unit 30 that communicates with the start end of the primary oxygen-containing gas introduction passage 10 at a location different from the turbine exhaust gas receiving unit 13
In addition, an air exhaust gas switching damper 31 that opens and closes the communication portion is provided in a communication portion with the air receiving portion 30 in the primary oxygen-containing gas introduction passage 10. Furthermore, in a state where each of the plurality of processing target gas injection ports 32 faces the combustion chamber 51,
In the primary oxygen-containing gas supply port 5, the gas supply ports 5 are provided side by side around the gas nozzles 4. Each of the processing target gas injection ports 32 is connected to a processing target gas introduction pipe 33. A processing target gas receiving section 34 communicating with the section is provided. The secondary swirler 18 is omitted.

Burner unit BU configured as described above
In the same manner as in the first embodiment, is mounted on the furnace wall of the combustion chamber 51 with its front face facing the burner mounting opening provided on the furnace wall of the combustion chamber 51 of the exhaust heat boiler SB.

The turbine exhaust gas supply path 20 is connected to the turbine exhaust gas receiving section 13, and the deheated exhaust gas return path 27 is connected to the economizer 55 in the exhaust duct 54 of the exhaust heat boiler SB.
A portion corresponding to the further downstream side and the turbine exhaust gas receiving portion 13 are connected, and the combustion air supply passage 21 is connected to the air receiving portion 30. That is, in the second embodiment, the deheated exhaust gas that has passed through the boiler main body 52 and the economizer 55 is configured to be supplied from the tertiary oxygen-containing gas supply port 7 into the combustion chamber 51. And the economizer 55 corresponds to the heated portion R. The temperature of the deheated exhaust gas after passing through the economizer 55 is 150 ° C.
And passes through the boiler body 52 and passes through the economizer 55
Since the temperature is further reduced as compared with the deheated exhaust gas before passing through, the heat-resistant specifications of the exhaust gas reducing blower 2, the deheated exhaust gas reducing passage 27, and the burner component can be set lower, and the cost can be reduced. In terms of advantages.

The fuel gas supply pipe 2 is connected to the fuel gas supply pipe 9.
4 is connected. Further, the processing target gas receiving section 34 is connected to a processing target gas supply path 35 to which a processing target gas to be deodorized, such as a gas generated in a coating booth, is supplied.

From the burner control unit 3, the combustion blower 1,
Exhaust gas reduction blower 2, secondary damper 15, tertiary damper 1
6. Turbine exhaust gas damper 22, air damper 23,
In addition to the operation control signals for the deheat exhaust gas damper 28, the on-off valve 25, and the proportional valve 26, the control signals for operation control for the primary damper 14 and the air exhaust gas switching damper 31, respectively, are also output.

When the turbine control unit 46 outputs a turbine operation signal indicating that the gas turbine GT is operating, as shown in FIG.
The turbine exhaust gas damper 22, the primary damper 14, the secondary damper 15, and the tertiary damper 16 are opened, the air damper 23, the air exhaust gas switching damper 31, and the deheated exhaust gas damper 28 are closed, and the combustion exhaust gas is closed. The blower 1 and the blower 2 for exhaust gas reduction are stopped, and the turbine exhaust gas is supplied to the primary oxygen-containing gas supply port 5 and the secondary oxygen-containing gas supply port 6.
And a tertiary oxygen-containing gas supply port 7 is supplied into each of the combustion chambers 51 to perform a normal combustion mode in which fuel gas from the gas nozzle 4 is burned. In FIG. 4, the flow of the turbine exhaust gas is indicated by solid arrows.

When the signal from the turbine control unit 46 switches from the turbine operation signal to a turbine stop signal indicating that the gas turbine GT has stopped, the burner control unit 3
Is a turbine exhaust gas damper 22, as shown in FIG.
The primary damper 14 and the secondary damper 15 are closed, the air damper 23, the air exhaust gas switching damper 31, the tertiary damper 16 and the deheated exhaust gas damper 28 are opened, and the combustion blower 1 and exhaust gas reduction are performed. By operating the air blower 2, air sufficient to burn the entire amount of fuel gas from the gas nozzle 4 is supplied from the primary oxygen-containing gas supply port 5 to the combustion chamber 51.
And the deheated exhaust gas after passing through the economizer 55 is supplied from the tertiary oxygen-containing gas supply port 7 into the combustion chamber 51 to execute a temporary combustion mode in which the fuel gas from the gas nozzle 4 is burned. In FIG. 5, the flow of air is indicated by a dashed arrow, and the flow of deheated exhaust gas is indicated by a dashed-line arrow.

The gas to be treated is the gas outlet 32 for each gas to be treated.
The gas to be treated is supplied to the combustion chamber 51 to be deodorized.

During execution of the temporary combustion mode, the burner control unit 3 controls the rotation speed of the exhaust gas reducing blower 2 so that the temperature detected by the backflow detecting temperature sensor 19 is maintained within a set temperature range for backflow prevention. Adjust.

When the switch from the temporary combustion mode switching command switch of the operation panel 29 to the temporary combustion mode is commanded, the burner control unit 3 switches from the normal combustion mode to the temporary combustion mode, and returns to the normal combustion mode return command switch. When a command is issued to return to the normal combustion mode from the temporary combustion mode, the mode is switched from the temporary combustion mode to the normal combustion mode.

Therefore, the combustion control means FC includes a burner control unit 3, an exhaust gas reducing blower 2, a primary damper 14, a secondary damper 15, a tertiary damper 16, and an air exhaust gas switching damper 3.
1, a turbine exhaust gas damper 22, an air damper 23, and a deheated exhaust gas damper 28.

As in the first embodiment, in the temporary combustion mode, nothing is supplied from the secondary oxygen-containing gas supply port 6 to the combustion chamber 51. However, as described in the first embodiment. For the same reason as described above, the burner unit BU is not overheated.

[Third Embodiment] A third embodiment will be described below with reference to FIGS. In the third embodiment, the oxygen content of the turbine exhaust gas is smaller than 10%, and in the burner B, the fuel gas cannot be burned only by the turbine exhaust gas. It is necessary to supply combustion air to burner B. The temperature of the turbine exhaust gas is about 500 ° C. The burner unit BU is configured similarly to the above-described first embodiment except for the configuration described below. That is,
The turbine exhaust gas receiving section 13 is provided so as to communicate only with the start end of the tertiary oxygen-containing gas introduction path 12, and starts with the start end of the primary oxygen-containing gas introduction path 10 and the secondary oxygen-containing gas introduction path 1.
1 is provided with an air receiving portion 30 communicating with the starting end. A primary damper 14 that opens and closes the communication part of the primary oxygen-containing gas introduction path 10 is provided in a communication part with the air reception part 30 in the primary oxygen-containing gas introduction path 10.
0, a secondary damper 1 that opens and closes the communication part.
A tertiary damper 16 that opens and closes the communication portion of the tertiary oxygen-containing gas introduction passage 12 with the turbine exhaust gas receiving portion 13 is provided. The secondary swirler 18
Omitted.

The burner unit BU configured as described above
In the same manner as in the first embodiment, is mounted on the furnace wall of the combustion chamber 51 with its front face facing the burner mounting opening provided on the furnace wall of the combustion chamber 51 of the exhaust heat boiler SB.

The turbine exhaust gas supply path 20 is connected to the turbine exhaust gas receiving section 13, and the deheated exhaust gas return path 27 includes a portion corresponding to a portion between the boiler main body 52 and the economizer 55 in the exhaust duct 54 of the exhaust heat boiler SB; Connected to the turbine exhaust gas receiving section 13, the combustion air supply path 21
Connect to air receiving unit 30. That is, in the third embodiment, the boiler main body 52 corresponds to the heated portion R. A fuel gas supply pipe 24 is connected to the fuel gas introduction pipe 9.

From the burner control unit 3, the combustion blower 1,
Exhaust gas reduction blower 2, secondary damper 15, tertiary damper 1
6. Turbine exhaust gas damper 22, air damper 23,
In addition to the control signal for controlling the operation of each of the deheat exhaust gas damper 28, the on-off valve 25, and the proportional valve 26, a control signal for controlling the operation of the primary damper 14 is also output.

When the turbine control unit 46 outputs a turbine operation signal indicating that the gas turbine GT is operating, as shown in FIG.
The turbine exhaust gas damper 22, the air damper 23, the primary damper 14, and the tertiary damper 16 are opened, the secondary damper 15 and the deheated exhaust gas damper 28 are closed, the combustion blower 1 is operated, and the exhaust gas is exhausted. Blower for reduction 2
Is stopped, the turbine exhaust gas is supplied from the tertiary oxygen-containing gas supply port 7 into the combustion chamber 51, and the air is supplied from the primary oxygen-containing gas supply port 5 into the combustion chamber 51. Is performed in the normal combustion mode. In FIG. 6, the flow of turbine exhaust gas is indicated by solid arrows, and the flow of air is indicated by broken arrows. In addition, from the primary oxygen-containing gas supply port 5, a smaller amount of air than the amount required to burn the entire amount of the fuel gas from the gas nozzle 4 is supplied. The gas is supplemented with oxygen in the turbine exhaust gas supplied from the supply port 7 to the combustion chamber 51.

When the signal from the turbine control unit 46 is switched from the turbine operation signal to a turbine stop signal indicating that the gas turbine GT has stopped, the burner control unit 3
As shown in FIG. 7, the turbine exhaust gas damper 22 is closed, the primary damper 14, the secondary damper 15, the tertiary damper 16, the air damper 23 and the deheated exhaust gas damper 2 are closed.
8 is opened, and the combustion blower 1 and the exhaust gas reduction blower 2 are operated to supply air sufficient to burn all the fuel gas from the gas nozzle 4 to the primary oxygen-containing gas supply port 5 and the secondary oxygen supply. It is supplied to the combustion chamber 51 from the port 6,
In addition, a temporary combustion mode in which the deheated exhaust gas after passing through the boiler main body 52 is supplied from the tertiary oxygen-containing gas supply port 7 into the combustion chamber 51 to burn the fuel gas from the gas nozzle 4 is executed. In FIG. 7, the flow of air is indicated by a dashed arrow, and the flow of deheated exhaust gas is indicated by a dashed-line arrow.

During execution of the temporary combustion mode, the burner control unit 3 controls the rotation speed of the exhaust gas reduction blower 2 so that the temperature detected by the backflow detecting temperature sensor 19 is maintained within a set temperature range for backflow prevention. Adjust.

When the switch from the temporary combustion mode switching command switch of the operation panel 29 to the temporary combustion mode is commanded, the burner control unit 3 switches from the normal combustion mode to the temporary combustion mode, and returns to the normal combustion mode return command switch. When a command is issued to return to the normal combustion mode from the temporary combustion mode, the mode is switched from the temporary combustion mode to the normal combustion mode.

Therefore, the combustion control means FC includes a burner control unit 3, an exhaust gas reduction blower 2, a primary damper 14, a secondary damper 15, a tertiary damper 16, and a turbine exhaust gas damper 2.
2. It is composed of a damper 23 for air and a damper 28 for deheated exhaust gas.

In the normal combustion mode, nothing is supplied to the combustion chamber 51 from the secondary oxygen-containing gas supply port 6, but for the same reason as described in the first embodiment, the burner unit is not used. The BU is not overheated.

[Another Embodiment] Next, another embodiment will be described. (A) In the first embodiment, a case has been described in which the secondary combustion gas supply port 6 supplies nothing to the combustion chamber 51 in the temporary combustion mode. Alternatively, air or deheated exhaust gas may be supplied from the secondary oxygen-containing gas supply port 6 to the combustion chamber 51. In the case of supplying air, the secondary damper 15 is opened, and in the case of supplying deheated exhaust gas, the deheated exhaust gas reducing passage 27 is placed downstream of the secondary damper 15 in the secondary oxygen-containing gas introduction passage 11. And a portion corresponding to the downstream side of the tertiary damper 16 in the tertiary oxygen-containing gas introduction path 12 so as to communicate with each other.

In the second embodiment, a case has been described in which the secondary combustion gas supply port 6 supplies nothing to the combustion chamber 51 in the temporary combustion mode. Alternatively, air or deheated exhaust gas may be supplied from the secondary oxygen-containing gas supply port 6 to the combustion chamber 51. When supplying the deheated exhaust gas, the secondary damper 15 is opened, and when supplying air, the air receiving unit 30 is connected to the starting end of the primary oxygen-containing gas introduction passage 10 and the secondary oxygen-containing gas is introduced. In addition to being provided so as to communicate with each of the start ends of the passages 11, an air exhaust gas switching damper 31 is also provided at a communication portion between the secondary oxygen-containing gas introduction passage 11 and the air receiving portion 30. The opening operation of the air exhaust gas switching damper 31 is performed.

(B) In the above embodiment, when the signal from the turbine controller 46 switches from the turbine stop signal to the turbine operation signal, the burner controller 3
It may be configured to automatically switch from the temporary combustion mode to the normal combustion mode.

(C) The shapes of the primary oxygen-containing gas supply port 5, the secondary oxygen-containing gas supply port 6, and the tertiary oxygen-containing gas supply port 7 are not limited to the shapes exemplified in the above embodiment. Can be changed as appropriate. For example,
A plurality of primary oxygen-containing gas supply ports 5 may be provided side by side around the gas nozzle 4. Further, a plurality of secondary oxygen-containing gas supply ports 6 may be provided side by side around the primary oxygen-containing gas supply port 5. Further, a plurality of tertiary oxygen-containing gas supply ports 7 are provided.
May be provided side by side around the secondary oxygen-containing gas supply port 6. Further, two rectangular tertiary oxygen-containing gas supply ports 7 are provided.
May be distributed and arranged on both sides of the secondary oxygen-containing gas supply port 6.

(D) In the above embodiment, the secondary oxygen-containing gas supply port 6 and the configuration related thereto may be omitted.

(E) The specific structure of the backflow detecting means is not limited to the backflow detecting temperature sensor 19 exemplified in the above embodiment. For example, when the air in the combustion chamber flows back into the tertiary oxygen-containing gas supply port 7 and flows in the tertiary oxygen-containing gas introduction passage 12, the pressure in the tertiary oxygen-containing gas introduction passage 12 changes. A pressure sensor for detecting the pressure in the passage 12 may be provided so as to function as backflow detecting means.

(F) In each of the first and third embodiments, the deheated exhaust gas returning passage 27 is connected to a portion of the exhaust duct 54 of the exhaust heat boiler SB downstream of the economizer 55 and connected to the boiler. The deheated exhaust gas after passing through the main body 52 and the economizer 55 may be supplied from the tertiary oxygen-containing gas supply port 7 into the combustion chamber 51. In this case, the boiler body 52 and the economizer 55
Corresponds to the heated portion R. In the second embodiment, the deheated exhaust gas returning passage 27 is connected to the exhaust duct 54 of the exhaust heat boiler SB.
The deheated exhaust gas passing through the boiler body 52 and passing through the economizer 55 is connected to the portion corresponding to between the boiler body 52 and the economizer 55 in the combustion chamber 51 through the tertiary oxygen-containing gas supply port 7. May be configured to be supplied. In this case, the boiler main body 52 is
Is equivalent to

(G) The position for taking out the deheated exhaust gas after passing through the heated portion R is not limited to the position exemplified in the above embodiment, and can be changed as appropriate. A configuration in which the heat is taken out at a position lowered to a temperature range of up to 300 ° C. is achieved by setting the heat-resisting specifications of the exhaust gas reducing blower 2, the deheated exhaust gas reducing passage 27 and the burner components to be low, and the exhaust gas reducing blower 2. This is advantageous in terms of reducing the power consumption.

(H) As a specific example of the combustion type prime mover, the gas turbine GT exemplified in the above embodiment is used.
However, the present invention is not limited to this, and may be a gas engine or the like.
Further, specific examples of the heated portion R are not limited to the boiler main body 52 and the economizer 55 of the exhaust heat boiler SB illustrated in the above embodiment, and may be, for example, various heating furnaces. (I) In the above embodiment, the burner B is configured to burn gas fuel such as city gas. However, the burner B may be configured to burn liquid fuel, or a mixture of gas fuel and liquid fuel may be used. You may comprise so that it may make it.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a cogeneration system using an exhaust gas reburning type combustion device according to a first embodiment.

FIG. 2 is a system diagram showing a configuration of an exhaust gas reburning type combustion apparatus according to the first embodiment and a control state in a normal combustion mode.

FIG. 3 is a system diagram showing a control state in an extra combustion mode in the exhaust gas reburning type combustion device according to the first embodiment;

FIG. 4 is a system diagram showing a configuration of an exhaust gas reburning type combustion apparatus according to a second embodiment and a control state in a normal combustion mode.

FIG. 5 is a system diagram showing a control state in an extraordinary combustion mode in an exhaust gas reburning type combustion device according to a second embodiment.

FIG. 6 is a system diagram showing a configuration of an exhaust gas reburning type combustion apparatus according to a third embodiment and a control state in a normal combustion mode.

FIG. 7 is a system diagram showing a control state in an extraordinary combustion mode in an exhaust gas reburning type combustion device according to a third embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 blower means 4 burner main body 5 main oxygen-containing gas supply port 7 auxiliary oxygen-containing gas supply port 9 fuel introduction pipe 10 main oxygen-containing gas introduction path 12 auxiliary oxygen-containing gas introduction path 19 backflow detecting means 20 motor exhaust gas supply path 24 fuel supply Pipe 27 Deheated exhaust gas returning path 51 Combustion chamber 52 Main heat exchanger (boiler body) 55 Heat exchanger for preheating feedwater (economizer) B Burner SU Burner unit FC Combustion control means GT Combustion motor R Heated part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Tanaka 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Yoshinobu Nagata 4-chome, Hirano-cho, Chuo-ku, Osaka-shi, Osaka 1-2-2 Inside Osaka Gas Co., Ltd. (72) Inventor Hiroshi Kobayashi 1-338 Nonakakita, Yodogawa-ku, Osaka City, Osaka Prefecture Inside Volcano Co., Ltd. (72) Yutaka Takamatsu 1 Nonakakita, Yodogawa-ku, Osaka City, Osaka Prefecture Vol.3, No.38 Inside Volcano Co., Ltd. (72) Inventor Minoru Soejima 1-33, Nonakakita, Yodogawa-ku, Osaka-shi, Osaka F-term inside Volcano Co., Ltd. GA53 GA56

Claims (4)

[Claims] 1. A fuel supply burner main body disposed facing a heating combustion chamber of a heated portion, a main oxygen-containing gas supply port disposed around the burner main body, and the main oxygen-containing gas. A burner provided with an auxiliary oxygen-containing gas supply port disposed farther from the burner body than a supply port, wherein the main oxygen-containing gas supply port is configured to supply a motor exhaust gas discharged from a combustion type motor or air from a blowing means to the main oxygen-containing gas supply port; Combustion control means for supplying normal gas to the combustion chamber and supplying the exhaust gas of the prime mover from the auxiliary oxygen-containing gas supply port into the combustion chamber to burn fuel from the burner body. An exhaust gas reburning type combustion device, wherein the combustion control means sends air sufficient to burn the entire amount of fuel from the burner body from the main oxygen-containing gas supply port to the combustion chamber. Supplying, and the deheated exhaust gas after passing through the heated portion is supplied from the auxiliary oxygen-containing gas supply port into the combustion chamber, and can be switched to a temporary combustion state in which fuel from the burner main body is burned. Exhaust gas reburning type combustion device configured. 2. A fuel introduction pipe communicating with the burner main body, a main oxygen-containing gas introduction passage communicating with the main oxygen-containing gas supply port, and auxiliary oxygen communicating with the auxiliary oxygen-containing gas supply port. A burner unit including a gas-containing gas introduction passage, a fuel supply pipe for supplying fuel, the blowing means, a motor exhaust gas supply passage through which motor exhaust gas is supplied from the motor, and the burner unit. The exhaust gas reburning type combustion device according to claim 1, wherein each of the deheated exhaust gas reduction passages for leading the deheated exhaust gas after passing through the heating section to be supplied into the combustion chamber from the auxiliary oxygen-containing gas supply port is connected. . 3. The main heat exchanger of the waste heat boiler and the deheated exhaust gas passing through the main heat exchanger are supplied to the main heat exchanger. The combustion control means comprises a heat exchanger for water supply preheating for preheating water, wherein the combustion control means removes the deheated exhaust gas after passing through the heat exchanger for water supply preheating from the auxiliary oxygen-containing gas supply port to the combustion chamber. The exhaust gas reburning type combustion apparatus according to claim 1 or 2, wherein the combustion apparatus is configured to supply the exhaust gas to the combustion apparatus. 4. A backflow detecting means for detecting in advance that gas in the combustion chamber flows back to the auxiliary oxygen-containing gas supply port is provided, and the combustion control means controls the combustion from the auxiliary oxygen-containing gas supply port. The amount of reduction of the deheated exhaust gas to be reduced into the chamber is configured to be adjustable, and the gas in the combustion chamber flows backward to the auxiliary oxygen-containing gas supply port based on the detection information of the backflow detection means. 2. The apparatus according to claim 1, wherein the amount of reduction of the deheated exhaust gas is adjusted so as to prevent the generation of heat.
The exhaust gas reburning type combustion device according to any one of claims 1 to 3.