JP2003074375A - Gas-turbine-incorporated boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that recovers, as steam, potential heat of a low temperature exhaust gas of a small gas turbine using a regenerative cycle and effectively uses the recovered steam, in a cogeneration system as a small boiler and small gas turbine combination. SOLUTION: An exhaust gas outlet of the gas turbine is connected direct to a combustion gas introducing chamber of a boiler to eliminate radiation loss, a condensing economizer is used to recover even latent heat of condensation, and topping of gas turbine combustion gas potential heat produces a higher temperature to recover waste heat as steam. The recovered steam is injected as saturated steam or superheated steam into a combustor to increase a shaft horsepower of the gas turbine. The injected steam is separated from exhaust gas in the condensing economizer and recovered as boiler water. The reheat of the exhaust gas with the steam, the injection of the steam and shrouding of the gas turbine and the boiler in an integral enclosure suppress or prevent white smoke, NOx and noise, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine built-in boiler in which a small boiler used for commercial use, small-scale industrial use, etc. and a small gas turbine are combined, and a cogeneration system using the boiler.

The gas turbine built-in boiler according to the present invention enables energy saving and electric output extraction of a small boiler used for commercial use, small-scale industrial use and the like.

[0003]

2. Description of the Related Art Conventionally, small once-through boilers and tube smoke tube boilers are used for air conditioning, commercial and small-scale industrial processes by utilizing the latent heat of condensation of low-pressure (about 0.7 MPa) saturated steam generated by them. It is used.

In such an application, since electric power is often used at the same time, a cogeneration system is installed in a relatively large facility, power is generated by a reciprocating engine or a gas turbine, and waste heat is used to heat a boiler. Steam is obtained by heating.

However, in such a conventional cogeneration, in the case of a reciprocating engine, the temperature of jacket water is too low to operate the steam boiler, and in the case of a gas turbine, a simple cycle In this case, the power generation efficiency cannot be maintained high unless the scale is large (several thousands kW or more).

Recently, a so-called micro gas turbine having an output of less than 300 kW and a centrifugal type compressor and expansion turbine has been put into practical use. Many micro gas turbines use a regeneration cycle, and even with a low pressure ratio (about 4), it is possible to obtain power generation efficiency (about 30%) equivalent to that of a gas turbine of several thousands kW class (pressure ratio of about 15). is there.

However, in the micro gas turbine, the expansion turbine inlet allowable temperature (about 900 ° C .; hereinafter, this temperature may be referred to as “TIT”) is limited and the exhaust gas temperature is low (about 250 ° C.). There is an inconvenience in using the exhaust gas. The former is because the metal blade cannot be air-cooled due to its small size or radiant flow structure, and the latter is because a regeneration cycle is used and waste heat is used for preheating combustion air. Therefore, in order to suppress the inlet temperature of the expansion turbine, in these micro gas turbines, excess air is compressed by a compressor and injected into a combustor to cool the combustor and dilute and cool the combustion gas.

Examples of means (two-fluid cycle) for returning the steam generated from the waste heat boiler to the combustor of the gas turbine or the expansion turbine to increase the shaft output of the turbine include a chain cycle and a flex cycle. The former is for blowing superheated steam, and the latter is for blowing a mixed gas of saturated steam and compressor outlet air. In both cases, saturated steam injection is avoided to suppress erosion of turbine blades.

Further, since a large amount of steam is injected, there are problems such as securing and cost of boiler water and its raw water, and generating white smoke when discharging steam-saturated exhaust gas.

When a gas turbine exhaust gas having a high residual oxygen concentration (about 15%) is burned with auxiliary fuel by using oxygen in the exhaust gas as an oxidant, energy saving can be achieved as compared with burning with fresh air. This is because the amount of heat for heating the fresh air is unnecessary, which is the energy saving principle of the so-called exhaust gas reburn boiler.

However, this exhaust gas re-combustion technology also has a problem that it cannot be used unless it is a large-scale application in which the investment can be recovered, because it is necessary to use a burner having a special structure that does not blow off even in low oxygen combustion.

[0012]

As described above, the conventional cogeneration is not efficient in terms of energy and economy unless it is a large-scale facility, and various restrictions are also imposed on waste heat utilization and steam utilization. There is.

Therefore, the present invention aims to provide an improved technique for conventional cogeneration. Specifically, the main purpose is to solve the following problems in a small cogeneration system with a power generation output of less than 300 kW by integrating a small gas turbine and a small boiler. (1) Even with a small cogeneration, waste heat is effectively recovered as steam while maintaining the power generation output at the same level as the medium size. (2) Use steam to further increase the electric output. (3) Secure stable performance that does not depend on on-site construction technology. (4) To provide a cogeneration system that is small, lightweight, and inexpensive. (5) The increase in boiler water consumption due to the adoption of the two-fluid cycle is suppressed. (6) Preventing or suppressing the emission of noise, nitrogen oxides (NO _x ), white smoke, etc.

[0014]

[Means for Solving the Problems] [Structure 1] A boiler incorporating a gas turbine according to the present invention has a small once-through type or a furnace using exhaust gas of a small gas turbine using a regeneration cycle as a heat source, as described in claim 1. A boiler having a smoke tube type boiler structure, in which gas turbine exhaust gas is directly guided to a combustion gas introduction chamber of the boiler without passing through a flue, and saturated steam is generated by using heat of the exhaust gas. It is a built-in gas turbine boiler.

Here, the combustion gas introduction chamber is a heat exchange chamber corresponding to a combustion chamber in a boiler that burns ordinary fuel. Normally, the combustion chamber of the boiler can be used as it is, but since the temperature of the combustion exhaust gas is low and no combustion space is required, heat transfer promotion fins can be attached to the inner surface of the combustion chamber, or heat transfer tubes can be added. The heat transfer area increasing means may be used in combination. Further, all or part of the gas turbine may be installed by being immersed in the combustion gas introduction chamber.

[Operation and Effect] If the exhaust gas of the small-sized gas turbine using the regeneration cycle is directly guided to the combustion gas introduction chamber of the boiler without passing through the flue as in the present configuration, all the heat of exhaust gas retained can be obtained without a temperature drop. Can lead to a boiler.
Further, since the heat insulating flue work at the installation site can be omitted, the cogeneration system can be constructed at low cost while ensuring reliability.

Since the exhaust gas temperature of a small-sized gas turbine using a regeneration cycle is about 250 ° C. and the temperature of 0.7 MPa saturated steam is about 165 ° C., in order to effectively recover the exhaust gas possession heat, a heat dissipation loss is required. It is extremely important to reduce the equipment such as flues that occur. Further, since the temperature difference is small, it is necessary to configure the boiler by increasing the heat transfer area in order to secure the boiler output.

However, when the heating gas is flue gas, the combustion chamber is not necessary, so that space can be used as a space for increasing the heat transfer area. The heat transfer area can be expanded by increasing the number of heat transfer tubes in a small once-through boiler and installing heat transfer fins on the inner surface of the furnace tube in a furnace tube smoke tube boiler. The increase of the heat transfer area by these means is advantageous because it does not increase the outer dimensions of the boiler.

The micro gas turbine is generally small and lightweight, and can be easily attached integrally to a small once-through boiler or a fire tube boiler. Moreover, if all or part of the gas turbine is installed by being immersed in the combustion gas introduction chamber,
It is also possible to make the whole compact.

When the gas turbine built-in boiler is integrally surrounded by a casing, the casing structure is devised so that
Both can be effectively soundproofed. In particular, when the noise generating portion of the gas turbine is immersed in the combustion gas introducing chamber, the boiler wall can also be used as a sound insulation wall, which is more effective for sound insulation.

[Structure 2] A gas turbine built-in boiler according to the present invention is a boiler having a small once-through type boiler structure in which exhaust gas of a small gas turbine using a regeneration cycle is used as a heat source, as described in claim 2. Direct the gas turbine exhaust gas to the combustion gas introduction chamber of the boiler without passing through the flue, and after heating the boiler feed water using the exhaust gas retention heat, the combustion gas retention heat of the gas turbine combustor This is a gas turbine built-in boiler configured to further heat the boiler feed water upstream of the expansion turbine using a part of it, and to separate the obtained brackish water two-phase flow by a gas-liquid separator to generate saturated steam.

Here, the gas-liquid separator usually corresponds to a steam drum in a boiler.

[Operation and Effect] In the case of the configuration 1, since the exhaust gas temperature of the regeneration cycle gas turbine is low, a large heat transfer area is required to recover the waste heat. Further, in the case of the micro gas turbine, there is a restriction that the temperature of the combustion gas must be lowered to the inlet allowable temperature (TIT; usually about 900 ° C.) due to the material restriction of the expansion turbine. Therefore, when using a gas turbine, the combustion gas is usually cooled to this temperature (TIT) by diluting and cooling the combustion gas with the compressed air obtained by the compressor.

In the case of a gas turbine, the power required to produce compressed air is recovered by the expansion turbine, but the recovery rate is determined by the product of the adiabatic efficiency of the compressor and expansion turbine. For a small gas turbine, each efficiency is 8
Since it is about 0%, although it is partially recovered through heat, about 30% of the diluted air compression power is lost.

Therefore, if the temperature of the combustion gas is cooled to TIT using the boiler water (or wet saturated steam) preheated with the exhaust gas, the combustion gas can be cooled and the dilution air compression power can be reduced at the same time. In addition to improving the efficiency of 1., the boiler water can be effectively heated, and the amount of steam (evaporation amount = boiler capacity) and quality (high pressure, high dryness, overheating) can be improved.

The combustor can be cooled with boiler water. In this case, cooling is performed by boiling heat transfer, so that cooling can be performed at a stable temperature and a small heat transfer area.

[Structure 3] In the gas turbine built-in boiler according to the present invention, as described in claim 3, an auxiliary burner is provided directly downstream of a small gas turbine using a regeneration cycle and directly connected to a combustion gas introduction port of the boiler. -The oxygen in the gas turbine exhaust gas is used as all or a part of the oxidant used in the auxiliary burner-The constitution 1 or 2 in which the heat retained by the gas turbine exhaust gas and the combustion heat of the auxiliary burner fuel are used as heat sources It is a gas turbine built-in boiler.

[Operation and Effect] With this configuration, the boiler is operated by freely changing the load of the gas turbine exhaust gas and the auxiliary burner within the input range of the rated total value or less regardless of the operating load of the gas turbine. be able to. This is convenient when controlling a boiler according to the operating load of steam utilization equipment.

Further, since the operation is performed as a so-called exhaust gas reburning boiler, the amount of heat required to heat the fresh air to the temperature of the exhaust gas is not required and energy is saved. An advantage of the present invention is that by incorporating a micro gas turbine into a small boiler and integrating it, an exhaust gas reburn burner with stable performance can be provided at low cost due to its mass production effect. Moreover, it is possible to manufacture an exhaust gas reburn burner having a structure that takes in the gas turbine exhaust gas in the most efficient manner, and the wasteful exhaust gas duct can be omitted.

[Configuration 4] In the gas turbine built-in boiler according to the present invention, as described in claim 4, all or part of the generated saturated steam is used for cooling the combustor of the small gas turbine or the combustion gas. By blowing all or part of the superheated steam obtained as a result of the heat exchange into the combustor of the gas turbine or the expansion turbine, the configuration 1 configured to increase the shaft output of the gas turbine
It is a boiler incorporating a gas turbine according to any one of 3 to 3.

[Operation and Effect] The steam obtained by the inventions according to the structures 1 to 4 is a low-pressure (about 0.7 MPa) saturated steam. Small boilers usually do not produce superheated steam because they do not have suitable applications such as power generation. Therefore, by cooling the gas turbine combustor with saturated steam and blowing superheated steam generated as a result of heat exchange into the combustor or expansion turbine, a two-fluid gas turbine is configured while suppressing erosion due to water droplets. Therefore, the shaft output of the gas turbine can be increased.

The method of this construction is a kind of chain cycle, but differs from the chain cycle in that superheated steam is obtained by cooling the combustor or the combustion gas. Moreover, since the pressure ratio is about 4 in a small gas turbine (the pressure ratio is about 15 in a medium-sized or larger gas turbine), low-pressure steam can be used.

By the way, if the steam pressure of the boiler is suppressed to the minimum pressure necessary for steam injection, the steam temperature is lowered (for example, the saturated steam temperature of 0.48 MPa is 150 ° C.).
Therefore, it is possible to lower the temperature by 15 ° C. as compared with 0.7 MPa steam, so that the amount of heat recoverable from the gas turbine exhaust gas can be increased.

Further, according to this structure, a part or all of the compressed air for cooling the combustor and for cooling the combustion gas is unnecessary, so that the amount of compressed air can be reduced. The effect is
As described above. In the case of a micro gas turbine, a high-speed generator is usually used as a generator, and the generated power is converted into direct current by a converter and then converted into alternating current at a commercial frequency by an inverter. It can be selected regardless of frequency. Therefore,
By changing the number of revolutions of the gas turbine, it is possible to change the capacity of the compressor, and it is possible to perform control to change the amount of dilution air according to the amount of injected steam. This makes it possible to maintain TIT at a constant value or below the upper limit value even if the amount of injected steam is changed.

It is also possible to control the amount of compressed air by providing a damper or a vane at the compressor inlet. This also makes it possible to reduce the air compression power and increase the gas turbine shaft output.

With this configuration, the shaft output of the gas turbine can be efficiently changed, and a cogeneration with a variable thermoelectric ratio can be provided. When the inventions of structure 3 are combined, a larger rate of change of thermoelectric ratio can be obtained.

[Structure 5] In the gas turbine built-in boiler according to the present invention, as described in claim 5, all or part of the generated saturated steam is generated from the flame existence region and flame existence region in the combustor. By blowing into at least one selected from the combustor portion at the upstream position, the vicinity of the fuel nozzle, and compressed air, the temperature of the combustion gas is set to the allowable turbine gas temperature (T
IT) Controlled below, and-Structure 1 configured to increase the shaft output of the gas turbine
It is a boiler incorporating a gas turbine according to any one of 3 to 3.

[Operation and Effect] This configuration differs from the chain cycle and the flex cycle in that all or part of the low-pressure saturated steam is blown into the small gas turbine. In this configuration, by setting the injection position of the steam to at least one location selected from the flame existence area in the combustor, the combustor portion upstream of the flame existence area, the vicinity of the fuel nozzle, and compressed air, high temperature combustion gas The mixed contact is performed to reduce the saturation level of the steam and obtain the erosion suppression effect equivalent to that of superheated steam injection. Further, the expansion turbine inlet allowable temperature (TIT) control is also performed by controlling the steam injection amount so as to be less than that.

As a result, the above-described compressed air reducing effect can be obtained, and the gas turbine can be operated so that the largest electric output can be obtained by introducing a large amount of steam within a range where the gas turbine does not cause a surge. it can.

Even if the dryness of the blown steam is low and erosion unfortunately occurs in the expansion turbine, the damage amount is small because the expansion turbine itself is cheap and easy to replace in the micro gas turbine, rather. The economic effect of improving power generation efficiency and power generation output is greater.

In addition, an effect of suppressing nitrogen oxides (NOx) due to a decrease in flame temperature is also exhibited in addition to the steam blowing.

[Structure 6] In the boiler incorporating the gas turbine according to the present invention, as described in claim 6, a condensation type economizer is attached to the exhaust gas outlet of the boiler, and the boiler feed water is supplied by using the heat recovered by the economizer. Along with preheating, the condensate separated and collected from the exhaust gas by the economizer is reused as a part of the boiler feed water.
It is a boiler incorporating a gas turbine according to any one of 1.

[Operation and Effect] In the present invention, the heat retained in the exhaust gas of the regeneration cycle gas turbine is used as the main heat source of the boiler, so heat is recovered from a large amount of low-temperature gas, and an economizer (coal-saving) is used to recover the heat. It is effective to install a vessel. Further, since the exhaust gas of the two-fluid gas turbine that performs steam injection contains a large amount of water vapor, and the exhaust gas dew point is rising, it is possible to recover the condensation latent heat of the water vapor in the exhaust gas at a relatively high temperature.

The condensed water of the exhaust gas separated and recovered by the economizer contains a small amount of carbon dioxide gas, nitrogen oxides, sulfur oxides, etc. generated by combustion, but the concentration is normal combustion exhaust gas due to steam injection. The corrosive environment is relatively mild because it is lower than that.

Therefore, by collecting a part of the large amount of boiler water consumed by the two-fluid gas turbine by the exhaust gas condensing economizer, the cost and the amount of use of the raw water can be reduced. As a result, although some costs are required for water treatment such as neutralization of condensed water, the costs can be suppressed as a whole and water resources can be saved.

[Structure 7] In the gas turbine built-in boiler according to the present invention, as described in claim 7, the exhaust gas in which a part of the contained water vapor is separated as condensed water by using a condensation type economizer attached to the boiler, The gas turbine built-in boiler according to configuration 6, wherein the steam discharged from the boiler or part of the recovered drain is reheated to prevent or suppress white smoke in the exhaust gas discharged from the stack. .

[Operation and Effect] Since the exhaust gas discharged from the condensing economizer is saturated with water vapor, if it is discharged from the chimney as it is, depending on the weather conditions, the water vapor will condense into water drops and become white smoke so that it can be seen visually. become. White smoke is particularly likely to occur during the winter when the temperature of the atmosphere is low and during the rainy season when the humidity is high. Although white smoke itself is not harmful, it is often necessary to prevent or suppress the whitening of water vapor because it is perceived as emitting harmful substances.

In this structure, the saturated exhaust gas discharged from the economizer is reheated by the steam discharged from the boiler or a part of the recovered drain to reduce the humidity thereof and prevent or suppress white smoke. As a method of reheating, for example, both indirect heating using a heat exchanger and direct heating by steam blowing are possible. The former has a feature that the amount of steam used is small and the amount of steam containing exhaust gas does not need to be increased, although the heat exchanger installation cost is involved.

Energy saving that the new energy is not required for this structure in order to prevent or suppress the generation of white smoke in the drain after the steam or the latent heat of vaporization that is originally the waste heat of the gas turbine is used. Is economical.

[0050]

BEST MODE FOR CARRYING OUT THE INVENTION A boiler incorporating a gas turbine according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an external perspective view showing an embodiment of a gas turbine built-in boiler according to the first aspect. In FIG. 1, the small gas turbine includes a centrifugal compressor 1, a radiant expansion turbine 2, a combustor 3, a regenerator 4, a generator 5 and a duct 6, and the outlet of the regenerator 4 is a boiler 11 It is directly connected to the combustion gas introduction chamber of (small once-through boiler) without passing through a flue. The small gas turbine may be, for example, a micro gas turbine, and the operation method is preferably a regeneration cycle to which a normal Brayton cycle is applied.

The gas turbine exhaust gas that has left the regenerator 4 enters the boiler 11 and exchanges heat with the boiler water in the heat transfer tube to generate saturated steam. As a result, the gas turbine built-in boiler generates two kinds of outputs, electricity and steam (heat).
Electricity can be used independently or in grid connection with commercial power.
The steam can be used not only for the process but also for heating.

In particular, when electricity is used independently and the generator 5 is a high-speed generator, the DC power obtained by AC-DC converting the generated power by the converter can be directly used for the DC motor. In addition, if the consumer equipment converts and uses alternating current with an appropriate frequency, it is efficient because the loss due to frequency conversion can be reduced. Examples of devices for which frequency conversion on the consumer device side is effective include fluorescent lamps, synchronous motors, and induction heating devices.

The boiler 11 may be a flue tube boiler, in which case the micro gas turbine section is placed horizontally. Moreover, you may comprise so that all or one part of a gas turbine may invade into a boiler combustion chamber. In this case, the gas turbine built-in boiler can be configured compactly and the noise of the gas turbine can be shielded. Furthermore, if the micro gas turbine and the boiler 11 are surrounded by an integral casing, a soundproof enclosure can be effectively installed.

Further, the heat exchange capacity of the regenerator 4 of the gas turbine can be adjusted. If the gas turbine exhaust gas is split upstream of the regenerator 4 and bypassed with the regenerator 4 and then combined with the exhaust gas passing through the regenerator, the heat exchange capacity of the regenerator is adjusted by adjusting the split flow ratio with a damper or the like. You can If the heat exchange amount is reduced, the temperature of the exhaust gas supplied to the boiler rises, and the steam output of the boiler can be increased.

FIG. 2 is a flow chart showing an embodiment of the gas turbine built-in boiler according to the present invention. The boiler water is pressurized by the feed water pump 13, enters the boiler 11, is heated by the exhaust gas discharged from the regenerator 4 of the gas turbine, and is further heated by the combustion gas in the gas turbine combustor 3 to become a brackish water two-phase flow. In a gas-liquid separator 17 (which usually corresponds to a steam drum of a boiler), saturated steam and saturated water are separated. The saturated steam is directly used for the process and heating, and the saturated water is partially blown and then returned to the boiler by the water supply pump 13. Since the boiler water is heated in two stages of the boiler can and the heat exchanger of the gas turbine combustor 3, the once-through type boiler is suitable.

The heating of the boiler water in the gas turbine combustor 3 is carried out by installing a heat exchanger in that portion, but it is convenient if it also serves to cool the combustor 3. Further, the combustion gas temperature needs to be cooled to the expansion turbine inlet allowable temperature (TIT) or lower, but as the cooling means, there are two types: a configuration using the present heat exchanger and a dilution cooling using compressed air from the compressor 1. There is. By increasing the cooling rate by this configuration, it is possible to obtain the effect of improving the performance and efficiency of the entire boiler incorporating the gas turbine by reducing the compressor shaft power and increasing the heat gain of the boiler steam.

FIG. 3 is an external perspective view showing an embodiment of a gas turbine built-in boiler according to the present invention. By directly connecting the auxiliary burner 12 for burning the auxiliary fuel to the downstream of the regenerator 4 of the gas turbine, it is possible to minimize the temperature decrease of the gas turbine exhaust gas.

In the auxiliary burner 12, the auxiliary fuel is burned by the residual oxygen in the gas turbine exhaust gas. Auxiliary burner 1
Since No. 2 is required to have low oxygen combustion performance, it is preferable to use a diffusion combustion system with swirling, which has high flame holding performance.

By supplying the auxiliary fuel, the steam generation amount of the boiler can be controlled within the range of the boiler rated output, independently of the operating load of the gas turbine, with the gas turbine waste heat amount as the minimum capacity.

Further, this structure can be implemented in combination with other structures in the present invention. Ingress and egress of steam in FIG. 3 represents one embodiment in combination with configuration 2.

4 and 5 are flow charts showing an embodiment of the gas turbine built-in boiler according to the present invention.
The saturated steam generated in the boiler 11 is sent to the gas turbine combustor 3 to cool the combustor 3 and / or the combustion gas in the combustor to obtain superheated steam.

The generated superheated steam is entirely combustor 3
To the inlet of the expansion turbine 2 (FIG. 5) to increase the axial power of the gas turbine. The surplus superheated steam is used as steam with a high degree of dryness for processes and other purposes. Exhaust gas re-combustion with auxiliary fuel and saturated steam can be used together.

FIG. 6 is a flow chart showing an embodiment of a gas turbine built-in boiler according to the present invention. Boiler 1
The saturated steam generated in 1 is injected into the flame existence region of the gas turbine combustor 3 or upstream thereof. The saturated steam is heated by a flame or a high temperature combustion gas, increases its dryness, enters the expansion turbine 2, and increases the gas turbine shaft output. The saturated vapor injection position may be in the flame existence region or in the upstream thereof, and may be the outlet of the compressor 1, the gas nozzle, or the vicinity thereof.

As a result, the two-fluid cycle can be normally operated without erosion even when saturated steam is used. In addition,
Even if the dryness of the saturated steam is extremely low and the water droplets cause erosion on the expansion turbine blade, the expansion turbine of the micro gas turbine can be replaced inexpensively and easily.

Further, since the combustion temperature of the flame can be lowered by blowing in the steam, it is also effective in reducing the NOx emission amount.

FIG. 7 is a flow chart showing an embodiment of a gas turbine built-in boiler according to claim 6. Boiler 1
Attaching a condensing economizer 14 to the exhaust gas outlet of 1,
Condensed water is recovered as a part of boiler feed water by condensing water vapor in the exhaust gas. When recondensing the condensed water into the boiler, a water treatment device 15 is provided as necessary to adjust the pH.
Conditioned water softening treatment or pure water treatment can also be performed.

As the gas turbine fuel, natural gas, L
Use clean fuel with low sulfur content such as PG and kerosene. When steam injection is performed on the gas turbine, a large amount of water vapor is contained in the exhaust gas, so this method is effective for saving water in the boiler raw water. Of course, since the latent heat of condensation of exhaust gas is used for preheating boiler feed water, it is also effective as a low temperature waste heat recovery means of a regeneration cycle gas turbine.

FIG. 8 is a flow chart showing an embodiment of the gas turbine built-in boiler according to the present invention. When the exhaust gas is cooled by the condensing economizer 14, the exhaust gas becomes saturated, so white smoke may be generated if it is directly discharged from the chimney to the outside. Therefore, condensing economizer 14
The exhaust gas emitted from the exhaust gas is reheated by the reheater 16 to be brought out of the saturated state, and the white smoke of the exhaust gas when the exhaust gas is emitted to the atmosphere from the chimney is prevented or suppressed.

As the heat source used for reheating, saturated steam from the boiler is used. Since the steam was originally generated by recovering the waste heat of the gas turbine exhaust gas, no new energy is required. It is also possible to use the sensible heat of the drain water (saturated water recovered after consuming the latent heat of steam) recovered from the process or heating as another heat source.

FIG. 9 is a flow chart showing an embodiment of cogeneration in which a conventional chain cycle is applied. The steam blown into the combustor 3 or the expansion turbine 2 is superheated steam.

[0072]

The gas turbine built-in boiler according to the present invention has the following excellent effects. (1) Even if it is a small cogeneration, the power generation output can be maintained at the same level as that of the medium size by adopting the regeneration cycle gas turbine. (2) Low-temperature waste heat from the regeneration cycle gas turbine can be effectively recovered as saturated or superheated steam. (3) By performing steam injection, the electric output can be further increased. (4) The thermoelectric ratio can be changed by burning the auxiliary fuel. (5) Stable performance can be secured regardless of on-site construction skill. (6) A cogeneration system can be provided in a small size, light weight, and at low cost. (7) The increase in boiler water consumption due to steam injection can be suppressed. (8) The generation of noise, nitrogen oxides (NOx), white smoke, etc. can be prevented or suppressed.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an embodiment of a gas turbine built-in boiler according to claim 1.

FIG. 2 is a flow chart showing an embodiment of a boiler incorporating a gas turbine according to claim 2.

FIG. 3 is an external perspective view showing an embodiment of a gas turbine built-in boiler according to claim 3;

FIG. 4 is a flowchart showing an embodiment of a gas turbine built-in boiler according to claim 4;

FIG. 5 is a flowchart showing another embodiment of the gas turbine built-in boiler according to claim 4;

FIG. 6 is a flowchart showing an embodiment of a gas turbine built-in boiler according to claim 5;

FIG. 7 is a flow chart showing an embodiment of a boiler incorporating a gas turbine according to claim 6;

FIG. 8 is a flow chart showing an embodiment of a gas turbine built-in boiler according to the present invention.

FIG. 9 is a flowchart showing cogeneration in which a conventional gas turbine chain cycle is applied.

[Explanation of symbols]

1 compressor 2 expansion turbine 3 combustor 4 regenerator 5 generator 6 air ducts 11 boiler 12 Auxiliary burner 13 Water supply pump 14 Condensed economizer 15 Water treatment equipment 16 Reheater 17 Gas-liquid separator (steam drum)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F22B 1/18 F22B 1/18 J K R (72) Inventor Masahide Tsujishita Hirano-cho, Chuo-ku, Osaka-shi, Osaka 4-1-2, Osaka Gas Co., Ltd.

Claims (7)

[Claims] Claim: What is claimed is: 1. A boiler having a boiler structure of a small once-through type or a flue tube type that uses the exhaust gas of a small gas turbine as a heat source using a regeneration cycle, wherein the gas turbine exhaust gas is directly supplied without passing through a flue. A gas turbine built-in boiler that guides to the combustion gas introduction chamber of the boiler and uses the heat of the exhaust gas to generate saturated steam. 2. A boiler having a small once-through type boiler structure in which the exhaust gas of a small gas turbine using a regeneration cycle is used as a heat source, and the gas turbine exhaust gas is directly introduced into the combustion gas of the boiler without passing through a flue. After heating the boiler feed water using the exhaust gas holding heat, the boiler heating water is further heated upstream of the expansion turbine by using a part of the combustion gas holding heat of the gas turbine combustor. Boiler with built-in gas turbine that separates brackish water two-phase flow with a gas-liquid separator to generate saturated steam. 3. An auxiliary burner is provided immediately downstream of a small gas turbine using a regeneration cycle and is directly connected to a combustion gas introduction port of a boiler, and The gas turbine built-in boiler according to claim 1 or 2, wherein oxygen is used, and heat of the gas turbine exhaust gas holding heat and auxiliary burner fuel combustion heat is used as a heat source. 4. All or part of the generated saturated steam is used for cooling a combustor of a small gas turbine or combustion gas, and all or part of superheated steam obtained as a result of the heat exchange is gas. The gas turbine built-in boiler according to any one of claims 1 to 3, wherein the shaft output of the gas turbine is increased by blowing the gas into a combustor of the turbine or an expansion turbine. 5. The whole or a part of the generated saturated steam,
By blowing into at least one location selected from the flame existence area in the combustor, the combustor portion at a position upstream of the flame existence area, the vicinity of the fuel nozzle, and compressed air, The gas turbine built-in boiler according to any one of claims 1 to 3, which controls and increases the shaft output of the gas turbine. 6. A condensation type economizer is attached to the exhaust gas outlet of the boiler to preheat the boiler feed water by using the heat recovered by the economizer, and The gas turbine built-in boiler according to any one of claims 1 to 5, which is reused as a part. 7. An exhaust gas obtained by separating a part of the contained steam as condensed water by using a condensing economizer incidental to the boiler: By reheating the steam discharged from the boiler or a part of the recovered drain, The gas turbine built-in boiler according to claim 6, wherein the exhaust gas emitted from the chimney is prevented or suppressed from becoming white smoke.