JP2002349801A - Exhaust heat recovery boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an efficiency and a responsiveness to a load variation of an exhaust heat recovery boiler without enlarging the exhaust heat recovery boiler. SOLUTION: A vapor generating heat exchanger of at least any of a re-heater 13, a super-heater 20 and an evaporator 27 is arranged in a passage of the combustion gas 4 of the exhaust heat recovery boiler 6. A re-heater 51 is provided which includes a catalyst combustion device having combustion catalysts 9, 16 and 23 in the front flow side of the heat exchanger and a gas-phase combustion device 27 disposed in the tail flow side thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exhaust heat recovery boiler for performing catalytic combustion and gas-phase combustion.

[0002]

2. Description of the Related Art In a gas turbine combined cycle power plant, combustion exhaust gas from a gas turbine for power generation is introduced into an exhaust heat recovery boiler, and steam is generated using a heat exchanger (heat transfer tube) of the boiler. It is led to a steam turbine and used for power generation.

In the combined cycle power plant,
It is important to raise the temperature of the flue gas discharged from the gas turbine on the upstream side of the heat exchanger (heat transfer tube) in order to increase the efficiency of the exhaust heat recovery boiler and improve the load fluctuation response.

[0004] In order to raise the temperature of the combustion exhaust gas in the exhaust heat recovery boiler, there is known an example in which a duct burner for performing flame combustion is provided near the inlet duct of the exhaust heat recovery boiler, and the combustion exhaust gas is reheated to increase the temperature. .

Japanese Patent Application Laid-Open No. H11-132401 discloses the following example in order to raise the temperature of combustion exhaust gas discharged from a gas turbine without performing flame combustion by a duct burner. That is, a combustion catalyst layer for both denitration is provided on the upstream side of each of the reheater and the superheater of the exhaust heat recovery boiler, and fuel is supplied to the combustion catalyst layer to perform reburning by catalytic combustion to reduce combustion exhaust gas. This is a method of raising the temperature to increase the exhaust heat recovery efficiency.

[0006]

The exhaust heat recovery boiler of the duct burner type has the following problems. Since the boiler duct is made longer than before so that the flame generated by the duct burner does not contact the boiler heat transfer tube, the exhaust heat recovery boiler becomes large. Equipment, such as an ignition burner, a flame combustion burner, and a flame detector, that accompany the duct burner is required, and the apparatus becomes complicated. The amount of NOx generated due to the generation of flame is large. Combustion catalyst fuel is limited to high calorie fuel.

The exhaust heat recovery boiler using the catalytic combustion system has the following problems. In catalytic combustion, if the combustion temperature exceeds 800 ° C., the deterioration of the catalyst becomes remarkable. Therefore, the operation range is restricted as compared with the duct burner method, and the efficiency of the boiler is increased by increasing the exhaust gas temperature. And the load fluctuation response cannot be improved. Therefore, it is difficult to perform catalytic combustion uniformly over the entire cross-sectional direction of the gas flow of the boiler duct, and there is a possibility that incomplete combustion gas flows out of the downstream side of the combustion catalyst and is discharged outside the boiler.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and achieve high efficiency of the heat recovery steam generator and improvement of load fluctuation response without increasing the size of the heat recovery steam generator. It is in.

[0009]

The above objects of the present invention can be solved by an exhaust heat recovery boiler having the following configuration. (1) In an exhaust heat recovery boiler in which at least one of a reheater, a superheater, and an evaporator is arranged in a flow path of a combustion exhaust gas, a combustion is performed upstream of the heat exchanger. An exhaust heat recovery boiler provided with a reheating device comprising a catalytic combustion device having a catalyst and a gas phase combustion device installed downstream of the catalytic combustion device. The exhaust heat recovery boiler has a configuration in which a catalytic combustion device having a combustion catalyst is provided on a downstream side of a heat exchanger provided with the reheating device including a catalytic combustion device and a gas phase combustion device on the upstream side. be able to.

(2) A steam generating heat exchanger including at least a superheater, an evaporator, and a economizer among the reheater, the superheater, the evaporator, and the economizer is disposed in the flue gas flow passage. In the exhaust heat recovery boiler, a reburning device including a catalytic combustion device having a combustion catalyst at least upstream of the superheater and a gas phase combustion device installed downstream of the catalytic combustion device is provided, and a reheating device is provided in front of the evaporator. An exhaust heat recovery boiler provided with a catalytic combustion device having a combustion catalyst on a flow side. At this time, a reheating device including a catalytic combustion device having a combustion catalyst and a gas phase combustion device installed downstream of the catalytic combustion device may be provided on the upstream side of the reheater.

[0011] The gas phase combustion device may have a fuel supply facility including a combustion dispersion pipe and a fuel nozzle, and the gas phase combustion device injects fuel into combustion exhaust gas passing through the catalytic combustion device. However, it is possible to adopt a configuration in which ignition and combustion are performed by residual heat of the combustion exhaust gas.

[0012]

According to the present invention, it is possible to raise the combustion temperature, which has been suppressed to a low temperature by catalytic combustion, to a maximum of about 1300 ° C. by causing gaseous combustion of fuel.
Gas-phase combustion ignites by injecting combustion catalyst fuel into the fuel based on residual heat generated by catalytic combustion, and does not require an ignition burner and purge air equipment.

Further, even when the combustion catalyst cannot perform uniform combustion over the entire cross-sectional direction of the catalyst layer and the unburned fuel flows to the downstream side, complete combustion of the unburned fuel is achieved by performing gas phase combustion. In addition, it is possible to prevent the unburned fuel from flowing to the downstream side of the exhaust heat recovery boiler, and it is possible to realize a reheating apparatus having high combustion stability. Therefore, a catalytic combustion device may be arranged on the downstream side of the heat exchanger provided with the reheating device on the upstream side.

The gas-phase combustion device is configured to inject fuel into the combustion exhaust gas passing through the catalytic combustion device disposed upstream of the combustion device, and to ignite and burn by the residual heat of the combustion exhaust gas. The fuel can be easily ignited and burned.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall configuration diagram of an exhaust heat recovery boiler according to a first embodiment of the present invention.

The exhaust heat recovery boiler 6 includes an inlet duct 5, a reheating device 51A, a reheater 13, a reheating device 51B, a superheater 20, a reheating device 51C, an evaporator 27, and a economizer 2.
8, a drum 32, and an outlet duct 50.

The reheating units 51A, 51B, 51C are respectively provided with fuel supply facilities 7, 14, 21 for combustion catalysts, combustion catalysts 9, 16, 23, and fuel supply facilities 10, 1, for gas phase combustion.
7 and 24 are provided.

Hereinafter, the present embodiment will be described for each system. In the gas turbine 1, gas turbine fuel supply equipment 2
By receiving a supply of gas turbine fuel such as LNG, LPG, propane, etc. and burning the fuel under high temperature and high pressure, power is generated by the generator 3 directly connected to the fuel and at the same time combustion exhaust gas 4 (about 550) is generated. ~ 580 ° C). The combustion exhaust gas 4 is introduced into an exhaust heat recovery boiler 6 through an inlet duct 5, and thereafter, the reheating unit 5
1A, 51B, 51C and the heat exchanger (reheater 1
3, heat exchange in the superheater 20, the evaporator 27, the economizer 28) is performed, and finally the chimney 30
Is derived.

Reheater 1 installed in waste heat recovery boiler 6
3, reheating units 51A, 51B and 51C are provided on the upstream side of the exhaust gas flow of the superheater 20 and the evaporator 27, respectively.

Hereinafter, using FIGS. 3 to 8 as examples of the combustion catalysts 9, 16 and 23 in FIG.
A gas-phase combustion device 55 as an example of a gas-phase combustion device provided at the tip of the gas-phase combustion fuel supply equipment 10, 17, and 24 in FIG. 1, and the reheating devices 51A, 51B, and 51 in FIG.
The reheating unit 51 will be described as an example of C.

First, the exhaust gas system will be described. FIG.
It is a figure explaining the whole composition of the reheating apparatus 51 provided in the exhaust gas flow upstream of the heat exchanger 57. The reheating unit 51 includes a combustion catalyst fuel supply device 56 including a catalyst combustion dispersion pipe 40 having a combustion catalyst fuel nozzle 41 in the duct casing 52 in the flow direction of the combustion exhaust gas 4A.
And a gas-phase combustion device 55 having a gas-phase combustion fuel dispersion pipe 42 having a gas-phase combustion fuel nozzle 43. A heat exchanger 57 is provided downstream of the reheating unit 51.

FIG. 4 shows an example of the structure of the combustion catalyst fuel supply system 56 in the cross section of the duct. In order to uniformly supply the combustion catalyst fuel 53 into the duct casing 52, for example, a combustion catalyst fuel distribution pipe 40 in which the combustion catalyst fuel nozzles 41 are arranged in a lattice pattern is provided. Regarding the structure of the combustion catalyst fuel supply equipment 56 in the duct cross section, as long as it can uniformly supply the combustion catalyst fuel 53 into the duct casing 52, regardless of its arrangement or form, for example, the combustion catalyst fuel may be used. The arrangement of the nozzles 41 may be staggered.

FIG. 5 shows an example of a sectional structure of the fuel supply equipment 56 for a combustion catalyst. The fuel 53 for combustion catalyst is injected from the fuel nozzle 41 for combustion catalyst provided in the dispersion pipe 40 for combustion catalyst, and is uniformly mixed with the combustion exhaust gas 4A. The combustion exhaust gas mixed with the combustion catalyst fuel 53 is supplied to the combustion catalyst 44.
And the catalytic combustion of low NOx with no flame increases the exhaust gas temperature. However, the supply amount of the fuel 53 is controlled so that the catalyst combustion temperature at this time is suppressed to a temperature at which the catalyst is not damaged (about 800 ° C.).

FIG. 6 shows an example of the structure of the combustion catalyst 44 in the cross section of the duct. Since the combustion catalysts 44 are disposed so as to be uniformly distributed in the duct casing 52, uniform catalytic combustion is performed over the entire cross section of the duct. In the downstream of the combustion catalyst 44, the gas phase combustion device 55 performs gas phase combustion.

FIG. 7 shows the structure of the combustion catalyst 44 and the gas-phase combustion device 55 provided on the downstream side thereof. FIG. 8 shows an example of the structure of the gas-phase combustion device 55 in the cross section of the duct. In the gas-phase combustion device 55, when the combustion catalyst fuel 54 is injected from the fuel nozzle 43 into the combustion exhaust gas 46 that has passed through the combustion catalyst 44,
Gas phase combustion fuel 54 is ignited and burned by residual heat 45 of the combustion exhaust gas after passing through combustion catalyst 44. here,
Although the example in which the combustion gas injection angle of the fuel nozzle 43 is arranged so as to be inclined with respect to the gas flow as shown in FIG. 7, if it is possible to substantially uniformly inject the fuel 54 into the combustion exhaust gas 46, the The arrangement and shape of the fuel nozzle 43 in the combustion gas injection direction may be any. For example, the arrangement of the nozzles 43 in the duct cross section shown in FIG. 8 may be changed in a staggered manner.

By performing gas-phase combustion in the gas-phase combustion device 55, it becomes possible to raise the combustion temperature, which has been suppressed to a low temperature by catalytic combustion, to a maximum of about 1300 ° C. In the gas phase combustion, the fuel for gas phase combustion is ignited by residual heat 45 generated by catalytic combustion, and an ignition burner and a purge air facility are not required.

Further, in the combustion catalyst 44, even if unburned fuel flows out to the downstream side because uniform combustion cannot be performed over the entire cross-sectional direction of the catalyst layer, complete combustion of unburned fuel is achieved by performing gas phase combustion. Thus, it is possible to prevent the unburned fuel from flowing out to the downstream side of the exhaust heat recovery boiler 6, and to realize a reheating apparatus having high combustion stability.

Further, as compared with the conventional flame combustion method using a duct burner, the catalytic combustion device performs uniform non-flame combustion without generating a flame.
Is installed, low NOx combustion performance is achieved as a whole for the reheating device 51.

In the combustion catalyst 44, the fuel 53 for the combustion catalyst and the residual O ₂ (usually 1
(3-14 vol% concentration).

Since the activation energy of the combustion reaction can be reduced in the catalytic combustion system as compared with the case of the flame combustion system, even the low calorie fuel which is difficult to stably burn in the flame combustion system can be used as the fuel 53 for the combustion catalyst. And it can be used stably.

Here, there is a possibility that unburned fuel in the low-calorie combustion catalyst fuel supplied to the combustion catalyst 44 may flow to the downstream side. By injecting and burning the caloric gas-phase combustion fuel, low-calorie unburned fuel can also be burned at the same time. Therefore, it is possible to prevent the unburned fuel from flowing to the downstream side of the reheating device 51. The exhaust gas whose temperature has been increased by the gas phase combustion in the gas phase combustion device 55 is subjected to heat exchange in the heat exchanger 57.

In the exhaust heat recovery boiler 6 according to this embodiment shown in FIG. 1, the reheating by the reheating device 13 and the heat exchange in the heat exchanger 57 are performed in order from the upstream side of the flue gas flow. The combustion exhaust gas, which has been repeatedly performed in the superheater 20 and the evaporator 27, is subjected to heat exchange between the exhaust gas side and the water supply side in the economizer 28, and the temperature is reduced.
After passing through the outlet duct 50 and the chimney 30, it is discharged into the atmosphere.

The above is the description of the exhaust gas system. Next, the water / steam system will be described. The feed water 31 pressurized by the boiler feed pump is subjected to heat exchange with exhaust gas in the economizer 28,
The water supply is heated. After that, it flows into the boiler drum 32,
After flowing into the evaporator 27 through the downcomer 32a and performing heat exchange, it returns to the boiler drum 32 through the riser 32b. The saturated steam 38 generated in the boiler drum 32 is superheated by the superheater 20 and then sent to the demand side as superheated steam 36. On the other hand, the high-pressure turbine exhaust 33 is
And heat is sent to the demand side as reheat steam 34.

FIG. 2 shows the exhaust gas in this embodiment.
The vapor temperature diagram is shown. Exhaust gas temperature A at the gas turbine outlet
Is raised by the combustion catalyst 9 upstream of the reheater 13 to a temperature B, and further raised to a temperature C by the gas-phase combustion device 10. In the reheater 13, the exhaust gas temperature decreases from the temperature C to the temperature D due to the heat exchange, and at the same time, the reheat steam temperature increases from the temperature Q to the temperature R. Next, the temperature of the exhaust gas is raised from the temperature D to the temperature E by the combustion catalyst 16 on the upstream side of the superheater 20, and then further raised from the temperature E to the temperature F by the gas-phase combustion device 17. In the superheater 20, the exhaust gas temperature is reduced from the temperature F to the temperature G with the heat exchange, and at the same time, the steam temperature is superheated from the drum saturation temperature O to the temperature P. Next, the temperature of the exhaust gas is measured by the evaporator upstream combustion catalyst 23.
After the temperature is increased from the temperature G to the temperature H in the above, the temperature is further increased from the temperature H to the temperature I by the gas-phase combustion device 24.
In the evaporator 27, the exhaust gas temperature decreases from the temperature I to the temperature J, and the steam side becomes constant at the saturation temperature N. Economizer 28
Then, as the exhaust gas temperature decreases from the temperature J to the temperature K, the feedwater temperature increases from the temperature L to the temperature M.

An operation method of the exhaust heat recovery boiler having the above configuration will be described. When the required amount of the reheat steam 35 generated from the exhaust heat recovery boiler 6 increases, in order to increase the amount of heat retained in the combustion exhaust gas 4 of the gas turbine 1, the reheating unit 51
Start reheating by A.

Specifically, when the required reheat steam amount 35 increases, supply of the fuel 8 for the reheater upstream combustion catalyst is started, and reheating is started in the reheater upstream combustion catalyst 9. . Along with this, the temperature of the combustion exhaust gas from the gas turbine 1 rises. With an increase in the supply amount of the combustion catalyst fuel 8,
Reaction heat is generated by the combustion, and the combustion temperature inside the catalyst increases. Therefore, the supply amount of the fuel 8 is controlled so as to suppress the temperature to a certain upper limit value (about 800 ° C.) at which the catalyst deterioration and the activity decrease do not occur.

When the temperature of the exhaust gas 12 exceeds this temperature range (about 800 ° C.) and the exhaust gas temperature 12 is further increased in response to the request of the reheat steam 35, the gaseous phase combustion fuel 11 is vaporized downstream of the combustion catalyst 9. By supplying to the phase combustion device 10,
The gas phase combustion is started, and the supply amount of the gas phase combustion fuel 11 is controlled to increase the temperature to a required exhaust gas temperature.

When the amount of unburned fuel generated in catalytic combustion is large, even if the temperature is below a certain temperature upper limit (about 800 ° C.) at which catalyst deterioration and activity decrease do not occur, as described above, the gas-phase combustion system 10 , The unburned fuel is burned by the gas-phase combustion device 10 and the temperature is increased to a required exhaust gas temperature.

Similarly, when the required amount of superheated steam 37 increases, the supply of the fuel 15 for the superheater upstream combustion catalyst is started to start catalytic combustion, and the exhaust gas temperature 19 is increased.
If it is necessary to increase the temperature of the exhaust gas, the supply of the fuel for upstream-side gas-phase combustion 18 is started to perform gas-phase combustion, and the temperature is increased to a required exhaust gas temperature.

In the present invention, since the reheating device 51C is also installed on the upstream side of the evaporator 27, the required saturated steam amount is 3
Similarly, when the fuel gas for the evaporator 9 is increased, the supply of the fuel 22 for the upstream combustion catalyst of the evaporator is started to start the catalytic combustion, and when it is necessary to further increase the exhaust gas temperature 26, the evaporator upstream The gas-phase combustion fuel 25 is started to be supplied, gas-phase combustion is performed, and the temperature is increased to a required exhaust gas temperature.

In this embodiment, an example is shown in which three reheating units 51A, 51B and 51C are provided on the upstream side of the exhaust gas flow of the reheater 13, superheater 20 and evaporator 27, respectively. However, the reheating device for some heat exchangers may be omitted, in which case, the heat exchanger to which the reheating device is to be installed is appropriately selected according to the operating conditions assumed for each plant. May be.

FIG. 9 shows an overall configuration diagram of an exhaust heat recovery boiler according to a second embodiment of the present invention. The description of the configuration and operation common to the first embodiment is omitted.

The exhaust heat recovery boiler 6A is an example in which the reheater 13 and the reheating device 51A on the upstream side of the exhaust gas flow in the first embodiment are omitted.

On the upstream side of the exhaust gas flow of the superheater 20 and the evaporator 27, reheating devices 51B and 51C are provided, respectively. Note that one of the reheating devices 51B and 51C may be omitted according to the operating conditions and the like assumed for each plant.

FIG. 10 shows an exhaust gas-steam temperature diagram of the embodiment shown in FIG. The exhaust gas temperature A 'at the outlet of the gas turbine 1 is raised to the temperature B' by the combustion catalyst 16 upstream of the superheater, and further raised to the temperature C 'by the gas-phase combustion device 17.

In the superheater 20, the temperature of the exhaust gas decreases from the temperature C 'to the temperature D' due to the heat exchange, and at the same time, the main steam temperature increases from the temperature L 'to the temperature M'. Next, after the temperature is increased from the temperature D 'to the temperature E' by the evaporator upstream combustion catalyst 23,
Further, the temperature is raised from the temperature E ′ to the temperature F ′ by the gas phase combustion 24. In the evaporator 27, the steam side becomes constant at the saturation temperature L 'to the extent that the exhaust gas temperature has decreased from the temperature F' to the temperature G '. In the economizer 28, as the exhaust gas temperature decreases from the temperature G ′ to the temperature H ′, the feedwater temperature increases to the temperature J ′.
To K ′.

The reheater 1 is connected to the waste heat recovery boilers 6 and 6A.
Whether or not to install the gas turbine 3 depends on the specifications of the gas turbine 1 and the like. Actually, the combustion temperature of the gas turbine 1 is 1
For the gas turbine 1 having a temperature of about 300 ° C. and an exhaust gas amount of about 1500 t / h or more, the reheater 13 is installed in the exhaust heat recovery boilers 6 and 6A, and the high-pressure exhaust exhausted from the high-pressure steam turbine is superheated again. The gas is sent to the low-pressure steam turbine to improve the power generation efficiency of the entire gas turbine combined cycle.

FIG. 11 shows an example of the overall configuration of an exhaust heat recovery boiler according to a third embodiment of the present invention. The description of the configuration and operation common to the above-described embodiment will be omitted.

The exhaust heat recovery boiler 6B is provided on the upstream side of the exhaust gas flow of the reheater 13 and the superheater 20, respectively, with the same reheating unit 51A as exemplified in the reheating unit 51 in the first embodiment. And a reheating device 51B, and a catalytic combustion device 61 having a combustion catalyst fuel supply device 21 and a combustion catalyst 23 installed upstream of the evaporator 27.

Reheat steam demand 35 and superheat steam demand 37
In the same manner as in the first embodiment, the reheaters 51A and 51B respectively raise the temperatures of the combustion exhaust gases 12 and 19, and the catalysts increase the saturated steam demand 39 as in the first embodiment. In the combustion device 61, the combustion exhaust gas 26 is heated by supplying the combustion catalyst fuel 22 from the combustion catalyst fuel supply equipment 21 to the combustion catalyst 23 to perform catalytic combustion.

According to the present embodiment, the reheating unit 51
Since the catalytic combustion device 61 is installed on the downstream side of A and 51B, the NOx concentration in the exhaust gas downstream of the catalytic combustion device 61 can be suppressed to be low.

The heat exchanger in which the reheating device is installed and the heat exchanger in which the catalytic combustion device 61 is installed are not limited to the above-described example. Even if a part of the reheating devices 51A and 51B is omitted, the catalyst may be omitted. The combustion device may be replaced with a reburning device installed in at least one heat exchanger, and the catalytic combustion device 61 installed in at least one other heat exchanger.

FIG. 12 shows an overall configuration diagram of an exhaust heat recovery boiler according to a fourth embodiment of the present invention. The description of the configuration and operation common to the above-described embodiment will be omitted.

The exhaust heat recovery boiler 6C of the present embodiment is provided with a reheating device 51B, which is the same as the reheating device 51A of the first embodiment, on the upstream side of the exhaust gas flow of the superheater 20. On the downstream side, a fuel supply system for combustion catalyst 2
1 and a catalytic combustion device 61 having a combustion catalyst 23 are installed.

In the present embodiment, in the exhaust heat recovery boiler 6C in which the reheater 13 is omitted in the first embodiment, the first to third embodiments are provided for the increase in the required amount of superheated steam 37. The combustion exhaust gas 19 is heated by the reheating device 51B in the same manner as described above, and the combustion exhaust gas 26 is heated by the catalytic combustion device 61 similarly to the third embodiment in response to the increase in the required amount of saturated steam 39. I do.

According to this embodiment, the reheating unit 51
Since the catalytic combustion device 61 is installed in the exhaust gas flow path on the downstream side of A and 51B, the NOx concentration in the exhaust gas on the downstream side of the catalytic combustion device 61 can be suppressed to a low level.

The arrangement of each heat exchanger of the exhaust heat recovery boiler according to the present invention described above in the exhaust heat recovery boiler and the arrangement order with respect to the exhaust gas flow are not limited to those described above, and a plurality of heat exchangers may be used. It may be divided and a reheating device may be provided on a part or the whole thereof.

[0058]

According to the present invention, in the exhaust heat recovery boiler, the equipment can be made compact, low NOx combustion, and reheating with low calorie fuel can be performed, and the exhaust heat recovery boiler does not flow out of incomplete combustion gas. This has the effect of achieving higher efficiency and improved load fluctuation responsiveness.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an exhaust heat recovery boiler according to a first embodiment of the present invention.

FIG. 2 shows a temperature diagram of exhaust gas and steam in the heat recovery steam generator of FIG.

FIG. 3 shows a configuration diagram of the reheating apparatus of FIG. 1;

FIG. 4 shows a structural example (duct cross section) of the combustion catalyst fuel supply equipment of FIG.

FIG. 5 shows a structural example (cross section in the gas flow direction) of the fuel supply equipment for a combustion catalyst of the present invention.

FIG. 6 shows a structural example (duct section) of the combustion catalyst of FIG.

7 shows a structural example (a cross section in the gas flow direction) of the combustion catalyst and the fuel supply equipment for gas phase combustion shown in FIG.

8 shows a structural example (duct cross section) of the gas-phase combustion fuel supply equipment of FIG.

FIG. 9 shows an overall configuration of an exhaust heat recovery boiler according to a second embodiment of the present invention.

FIG. 10 shows a temperature diagram of exhaust gas and steam in the exhaust heat recovery boiler of FIG.

FIG. 11 shows an overall configuration of an exhaust heat recovery boiler according to a third embodiment of the present invention.

FIG. 12 shows an overall configuration of an exhaust heat recovery boiler according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Gas turbine fuel supply equipment 3 Generator 4, 4A Gas turbine combustion exhaust gas 5 Inlet duct 6, 6A, 6B, 6C Exhaust heat recovery boiler 7, 14, 21, 56 Fuel supply equipment for combustion catalyst 8, 15, 18, 22, 25, 53 Fuel for combustion catalyst 9, 16, 23, 44 Combustion catalyst 10, 17, 24 Fuel supply equipment for gas phase combustion 11, 18, 25, 54 Fuel for gas phase combustion 12, 19, 26, 29 flue gas 13 reheater 20 superheater 27 evaporator 28 economizer 30 chimney 31 boiler feed water 32 boiler drum 32a downcomer 32b riser 33 high-pressure turbine exhaust 34 reheat steam 35 reheat steam demand 36 superheat steam 37 superheat Required amount of steam 38 Saturated steam 39 Required amount of saturated steam 40 Fuel dispersion pipe for combustion catalyst 41 Fuel nozzle for combustion catalyst 42 Fuel for gas phase combustion Discharge tube 43 Gas-phase combustion fuel nozzle 45 Residual heat of combustion exhaust gas 46 Combustion exhaust gas after passing through combustion catalyst 50 Outlet duct 51, 51A, 51B, 51C Reheating device 52 Duct casing 55 Gas-phase combustion device 57 Heat exchanger 61 Catalyst Combustion equipment

Claims (8)

[Claims] An exhaust heat recovery boiler in which at least one of a reheater, a superheater, and an evaporator is disposed in a flow path of a combustion exhaust gas, wherein the heat exchanger for generating steam is located upstream of the heat exchanger. An exhaust heat recovery boiler further comprising a reburning device comprising a catalytic combustion device having a combustion catalyst and a gas phase combustion device installed downstream of the catalytic combustion device. 2. A catalytic combustion system comprising: a reheating device provided upstream of at least one of the reheater, superheater, and evaporator; and a combustion catalyst downstream of the heat exchanger. The heat recovery steam generator according to claim 1, further comprising an apparatus. 3. The exhaust heat recovery boiler according to claim 1, wherein the gas phase combustion device has a fuel supply facility including a combustion dispersion pipe and a fuel nozzle. 4. The gas-phase combustion device according to claim 1, wherein the fuel is injected into combustion exhaust gas passing through the catalytic combustion device, and is ignited and burned by residual heat of the combustion exhaust gas. Exhaust heat recovery boiler as described. 5. A reheater, superheater,
In an exhaust heat recovery boiler in which a steam generating heat exchanger including at least a superheater, an evaporator, and a economizer is disposed, a catalytic combustion having a combustion catalyst at least upstream of the superheater. Exhaust heat characterized by providing a reburning device consisting of an apparatus and a gas phase combustion device installed downstream of the catalytic combustion device, and providing a catalytic combustion device having a combustion catalyst upstream of the evaporator; Recovery boiler. 6. A reheating device comprising a catalytic combustion device having a combustion catalyst also on the upstream side of the reheater and a gas-phase combustion device installed downstream of the catalytic combustion device. The heat recovery steam generator according to claim 5, wherein 7. The exhaust heat recovery boiler according to claim 5, wherein the gas phase combustion device has a fuel supply facility including a combustion dispersion pipe and a fuel nozzle. 8. The gas-phase combustion device according to claim 5, wherein fuel is injected into combustion exhaust gas passing through the catalytic combustion device, and the fuel is ignited and burned by residual heat of the combustion exhaust gas. Waste heat recovery boiler.