JP2002004945A - Thermo-electric ratio control method of gas turbine cogeneration system of small capacity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate a system with high efficiency at all times without the excess or the shortage of the heat on the output side by adjusting a thermo-electric ratio of the system output to be agreed with a thermo-electric demand ratio on the load side in a gas turbine cogeneration system of small capacity. SOLUTION: In this gas turbine cogeneration system of small capacity comprising a gas turbine 1, a generator 5, a compressor 2, a regenerator 3, a combustor 4 and an exhaust heat recovering heat exchanger 6, and supplying a high temperature turbine exhaust gas G1 from the gas turbine 1 to the exhaust heat recovering heat exchanger 6 through the regenerator 3, a by-pass passage 10 for the high temperature turbine exhaust gas G1, provided with a control valve 11 is mounted on the regenerator 3, and an opening of the control valve 11 is adjusted corresponding to the thermal load 8 of the exhaust heat recovering heat exchanger 6 to control the thermo-electric ratio Q of the system output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a thermoelectric ratio of an output in a gas turbine cogeneration system for simultaneously supplying electric power and hot water, steam or cold water. It is mainly applied to a small-capacity gas turbine cogeneration system used alone or in a combination of a plurality of units in an office, a greenhouse farm, an apartment house, or the like.

[0002]

2. Description of the Related Art A cogeneration system (cogeneration system) combining a gas turbine generator, an exhaust gas boiler, and the like has been widely known for some time, and has been put to practical use. This cogeneration system drives a turbine generator to obtain electric power, and recovers heat of high-temperature exhaust gas from a gas turbine by an exhaust heat boiler or an exhaust heat hot water boiler to obtain steam or hot water. Business establishments and the like that require hot water, steam, and cold water at the same time have improved overall energy efficiency and economical efficiency as compared to a case where power and hot water are separately supplied.

[0003] By the way, the conventional systems of this type have a relatively large capacity of about 5000 KW, and are mainly composed of a power generator, and the exhaust heat thereof is to be recovered by an exhaust gas boiler. It is assumed that. But,
In recent years, the review of the cogeneration system has been promoted from the viewpoint of energy saving, and accordingly, a small-capacity gas turbine cogeneration system having a capacity of about 15 to 100 kW has been widely used.

FIG. 6 is a block diagram showing an example of a conventional small-capacity gas turbine cogeneration system of this kind. A gas turbine 1, a compressor 2, a regenerator 3, a combustor 4, a generator 5, a waste heat A gas turbine cogeneration system is constituted by the recovery heat exchanger (exhaust heat hot water boiler or exhaust heat steam boiler) 6 and the like. Thus, the combustion air A is first compressed in the compressor 2 directly connected to the gas turbine 1 and then guided to the regenerator 3. Regenerator 3
The compressed air guided to the gas turbine 1
After being preheated by the hot turbine exhaust gas G ₁ and the heat exchange ° C., it is supplied to the combustor 4. In the combustor 4, the preheated combustion air A and the supplied fuel gas F perform mixed combustion to generate a high-temperature combustion gas of about 850 ° C. The high-temperature combustion gas drives the gas turbine 1 to rotate, and the compressor 2 and the generator 5 directly connected to the gas turbine 1 rotate to generate power.

The high-temperature combustion gas generated in the combustor 4 undergoes adiabatic expansion to rotate the turbine 1 to about 60 degrees.
High-temperature turbine exhaust gas G _{1 at} 0 ° C. is sent to the regenerator 3, where it exchanges heat with the compressed air A to become turbine exhaust gas G _{2 at} about 270 ° C. The turbine exhaust gas G ₂ is subsequently introduced into the exhaust heat recovery heat exchanger 6, generates hot water (or steam or cold water), and is then emitted into the atmosphere as exhaust gas G ₀ of about 90 ° C.

For example, the fuel F is supplied to the city gas 13A (9.7).
Nm ³ / h, 9930 kcal / Nm ³ , heat input 112
In the case of a gas turbine cogeneration system having a small capacity (KW), the generator output is usually about 28 KW and the heat recovery amount is about 56 KW, and the overall energy efficiency of the entire system is about 75%.

By the way, the flow rate of the hot turbine exhaust gas G ₁ to be discharged from the gas turbine 1, the gas turbine 1
Of is in the output substantially proportional, as a result, the regenerator 3 substantially gas turbine 1 even when the temperature of the turbine exhaust gas G ₂ discharged from the
Will change in proportion to the output. This is because the heat transfer area of the regenerator 3 is constant, so that the heat exchange amount does not fluctuate greatly. In other words, if increased output of the gas turbine 1, the flow rate and temperature of the turbine exhaust gas G ₂ also rises together, and conversely, if lowering the output of the gas turbine 1, the flow rate and temperature of the turbine exhaust gas G ₂ is Both decrease.

On the other hand, in the heat recovery amount in the exhaust heat withdrawing heat exchanger 6 is determined by the flow rate and temperature of the turbine exhaust gas G _2. Therefore, the gas turbine output, that is, the generator output, and the amount of exhaust heat recovery are in a proportional relationship, whereby the thermoelectric ratio Q = the ratio between the electric output Pe of the generator 5 and the heat output Te of the exhaust heat recovery heat exchanger 6 is obtained. Te / Pe over the power range of 100-30% of the turbine cogeneration system,
It is almost constant.

For example, in the small-capacity gas turbine cogeneration system exemplified above, the generator output Pe = 28 KW and the thermal output Te = 56 K under the rated output.
W, the thermoelectric ratio Q becomes 2, and this thermoelectric ratio Q is kept substantially constant even if the output of the system is reduced, and cannot be adjusted to an appropriate value.

By the way, the ratio Q 'between the power demand Pe' of the power load 7 and the heat demand Te 'of the heat load 8 (thermoelectric demand ratio Q')
= Te '/ Pe') is always about 2, but there is no particular problem. However, when the thermoelectric demand ratio Q '= Te' / Pe 'fluctuates greatly, the thermoelectric ratio Q of the system output becomes large. If it is always constant, the electric output Pe or the thermal output Te
Surplus or shortage. Therefore, it is necessary to dissipate excess heat by a cooling tower or the like, or to process excess power by a power storage facility, power sales, or the like, which leads to a reduction in overall energy efficiency of the entire system.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the conventional small-volume gas turbine cogeneration system, that is, the ratio Q () of the generator output Pe to the heat output Te on the system side. Since the thermoelectric ratio Q = Pe / Te) is always substantially constant, the power demand Pe ′ of the power load 7
Q ′ of the heat demand Te ′ of the heat load 8 (thermoelectric demand ratio Q ′
If = Te '/ Pe' is different from the thermoelectric ratio Q, the problem of surplus in either power or heat and the overall energy efficiency of the entire system is reduced is not solved. High temperature turbine exhaust gas G _{1 in} regenerator
By adjusting the amount of heat recovered from the system, the thermoelectric ratio Q of the system output approaches the actual thermoelectric demand ratio Q ', so that the gas turbine cogeneration system can always be operated with high overall energy efficiency. A method for controlling a thermoelectric ratio of a gas turbine cogeneration system is provided.

[0012]

SUMMARY OF THE INVENTION The present inventors have developed and tested a number of small-capacity gas turbine cogeneration systems and have been able to vary the amount of heat recovered from high temperature turbine exhaust gases in regenerators by a significant amount. It has been found that the turbine output (that is, the generator output) and the high-temperature turbine exhaust gas flow rate are kept substantially constant as long as the supply amounts of the combustion air A and the fuel F are not changed. The present invention has been created based on the above knowledge of the inventors, and the invention of claim 1 has a gas turbine, a generator, a compressor, a regenerator, a combustor, an exhaust heat recovery heat exchanger, In a small-capacity gas turbine cogeneration system configured to supply a high-temperature turbine exhaust gas from a gas turbine to a waste heat recovery heat exchanger via a regenerator, the high-temperature turbine exhaust gas having a control valve in the regenerator The basic configuration of the present invention is to provide a bypass passage and to control the thermoelectric ratio of the system output by adjusting the opening of the control valve according to the heat load of the exhaust heat recovery heat exchanger.

According to a second aspect of the present invention, there is provided a gas turbine, a generator, a compressor, a regenerator, a combustor, and an exhaust heat recovery heat exchanger. Combustion air from the compressor passes through the regenerator to the combustor. In a small-capacity gas turbine cogeneration system configured to supply, a bypass passage for combustion air provided with a control valve is provided in the regenerator, and the control valve is controlled according to the heat load of an exhaust heat recovery heat exchanger. The basic configuration of the present invention is to control the thermoelectric ratio of the system output by adjusting the opening.

According to a third aspect of the present invention, there is provided a gas turbine, a generator, a compressor, a regenerator, a combustor, and an exhaust heat recovery heat exchanger, and recovers high-temperature turbine exhaust gas from the gas turbine through the regenerator. In a small-capacity gas turbine cogeneration system configured to supply a combustion air from a compressor to a combustor through a regenerator while supplying to a heat exchanger, a high-temperature exhaust gas having a control valve in the regenerator is provided. By providing a bypass passage for combustion air having a bypass passage and a control valve each having a control valve, and adjusting the opening degree of one or both of the control valves according to the heat load of the exhaust heat recovery heat exchanger, the system The basic configuration of the present invention is to control the thermoelectric ratio of the output.

According to a fourth aspect of the present invention, a gas turbine, a generator, an air compressor, a regenerator, and a combustor are integrally assembled with each other in the first, second, or third aspect of the present invention. In addition to the turbine generator unit, the exhaust heat recovery heat exchanger is an exhaust heat boiler or a vacuum type exhaust heat hot water boiler.

According to a fifth aspect of the present invention, in the first, second or third aspect of the present invention, the fluctuation of the heat load is detected by detecting the temperature of the still water or the generated steam pressure of the exhaust heat recovery heat exchanger. The opening degree of the control valve is adjusted based on the detected can water temperature or the generated steam pressure.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a small-capacity gas turbine cogeneration system according to a first embodiment of the present invention. In FIG. 1, the same members as those in FIG. 6 are denoted by the same reference numerals. Further, the basic configuration of the gas turbine cogeneration system shown in FIG. 1 is almost the same as the conventional system shown in FIG. 6, and therefore the detailed description is omitted here.

Referring to FIG. 1, in the present embodiment,
Provided with a high-temperature turbine bypass 10 of the exhaust gas G ₁ flowing into the regenerator 3 from the gas turbine 1 to the regenerator 3, the point which is interposed a control valve 11 in the bypass passage 10 is different from the previous system configuration . Combustion air A
Is compressed by the compressor 2, and the compressed combustion air A is preheated in the regenerator 3 by the high-temperature turbine exhaust gas G ₁ a and then supplied to the combustor 4. In the combustor 4, the preheated combustion air A and the supplied fuel F perform mixed combustion, and the generated high-temperature combustion gas drives the gas turbine 1 to rotate. In addition, the high-temperature turbine exhaust gas G ₁ adiabatically expanded in the gas turbine 1 is supplied to the high-temperature turbine exhaust gas passage 9.
, The part G _1b flows into the bypass passage 10 and the remaining part G _1a flows into the regenerator 3.

After the high-temperature turbine exhaust gas G _1a flowing into the regenerator 3 exchanges heat with the compressed air A, the high-temperature turbine exhaust gas G _1a is led out through the turbine exhaust gas passage 12 to the exhaust heat recovery heat exchanger 6 side.
The high-temperature turbine exhaust gas G _1b diverted through the bypass passage 10 is merged with the high-temperature turbine exhaust gas G _1b and flows into the exhaust heat recovery heat exchanger 6, where the exhaust heat is recovered, and the high-temperature water W ₁ is generated.

The flow rate of the high-temperature turbine exhaust gas G _1b diverted to the bypass passage 10 is continuously controlled by adjusting the opening of the control valve 11 in accordance with the increase / decrease of the heat load 8. As a result, the thermoelectric ratio Q (Te / P) between the electric output Pe of the generator 5 and the heat output Te of the exhaust heat recovery heat exchanger 6 is obtained.
e = Q) is matched with the ratio Q 'between the actual power load Pe' and the thermal load Te '(thermoelectric demand ratio Q' = Te '/ Pe').

For example, when the heat demand Te 'of the heat load 8 is small, the opening degree of the control valve 11 is reduced (the valve is throttled), and the flow rate of the high-temperature gas turbine exhaust gas G _1b is reduced to reduce the exhaust heat recovery heat. By reducing the heat input to the exchanger 6, the thermoelectric ratio Q of the system output is reduced. The temperature of the combustion air A is increased in order to increase the flow rate of the hot turbine exhaust gas G _1a to flow into the regenerator 3, the power generation efficiency of the generator 5 is to be raised slightly from this. Conversely, when the heat demand Te 'of the heat load 8 increases, the control valve 1
1 by opening the valve (opening the valve) and increasing the flow rate of the high-temperature gas turbine exhaust gas G _1b , thereby increasing the heat input to the exhaust heat recovery heat exchanger 6, and the thermoelectric ratio Q (Q = Te / P)
e) increase.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A package using a gas turbine generator unit U in which a gas turbine 1, a compressor 2, a regenerator 3, a combustor 4, a generator 5 and the like as shown in FIG. Ratio of the control valve 11 and the high temperature exhaust gas G when the control valve 11 is opened under the condition that the supply amounts of the fuel F and the combustion air A are substantially constant while the small-capacity gas turbine cogeneration system is operated. ₁ of the flow, regenerator total heat was measured overall efficiency and the like. The fuel F is city gas 13A (9.7 Nm ³ / h, 9930 kcal / h).
Nm ³ , heat input 112 kW) and the generator output Pe of the gas turbine generator unit U in the rated state is 28
KW, the heat output Te of the exhaust heat recovery heat exchanger (vacuum exhaust heat hot water boiler) 6 is 56 KW, and the thermoelectric ratio Q is 2.

Table 1 shows the results of a thermoelectric ratio control test using the gas turbine cogeneration system.

[0024]

[Table 1]

As is clear from Table 1, the control valve 1
1 and the flow rate of high-temperature turbine exhaust gas G ₁ 81
40.4, 178.4, 44 out of 5.5 Nm ³ / h
By bypassing (G _1b ) 5.4 and 627.6 Nm ³ / h, the temperature of the turbine exhaust gas G ₂ flowing into the exhaust gas hot water boiler 6 becomes 305.25, 329.71, and 41.
0.49, 490.11 ° C and the exhaust heat recovery amount is 80
504.6, 87032, 108790, 130548
kcal / h. On the other hand, since the output Pe of the gas turbine generator is substantially constant (25.3 KW), the thermoelectric ratio Q is 2.7, 3, 4, and 5. In addition, the overall efficiency was not reduced without decreasing 80.2, 81.4, 84.6, 86.
It rises to 8%.

It is to be noted that the control valve 11 is controlled by the fluctuation of the heat load 8.
As a method of controlling the opening degree, for example, a temperature detection sensor (not shown) is provided in the low-temperature water inlet pipe 13 or the high-temperature water outlet pipe 14 of the waste heat hot water boiler 6, and the fluctuation of the heat load is detected by the hot water W.
The opening degree of the control valve 11 can be controlled by taking the temperature change as ₁ . Further, in the embodiment of FIG. 1, an exhaust heat hot water boiler is used as the exhaust heat recovery heat exchanger 6, but it is a matter of course that an exhaust heat steam boiler may be used. Detects a change in the heat load 8 from a change in the steam pressure, and detects a change in the control valve 11 based on a signal from a steam pressure detection sensor provided at a steam outlet of the waste heat steam boiler.
May be controlled.

FIG. 2 is a block diagram of a small-capacity gas turbine cogeneration system according to a second embodiment of the present invention. In the second embodiment, as shown in FIG. 2, the regenerator 3
A bypass passage 15 for the compressed air A flowing to the side is provided, and a control valve 16 is provided in the bypass passage 15. That is, a part A ₂ of the combustion air A flowing out of the compressor ₂ is directly supplied to the combustor 4 through the bypass passage 15, and the remaining A ₁ of the combustion air A is preheated in the regenerator 3. Are supplied to the combustor 4.

[0028] Therefore, now, when the heat demand Te thermal load 8 'is increased, increasing the flow rate of the bypass air flow A ₂ to increase the opening of the control valve 16. This reduces the flow rate of the combustion air A ₁ flowing to the regenerator 3, the heat recovery amount from the in the hot turbine exhaust gas G ₁ to the regenerator 3 is lowered. As a result, the temperature of the turbine exhaust gas G ₂ discharged from the regenerator 3 rises, heat output Te of exhaust heat recovery heat exchanger 6 is increased.

On the other hand, when the temperature of the combustion air A supplied to the combustor 4 is reduced, the efficiency of the gas turbine 1 is slightly reduced, but the output is not greatly reduced. As a result, the thermoelectric ratio Q (Te /
Pe) increases and the actual power load Pe ′ and the thermal load Te ′
With the thermoelectric ratio Q matched to the thermoelectric demand ratio Q ′ (Te ′ / Pe ′), the gas turbine cogeneration system is operated with high efficiency.

[0030] In the case where the heat load Te of the heat load 8 'is decreased, lowering the opening degree of the control valve 16 contrary to the above, the heat recovery amount by the in combustion air A ₁ to the regenerator 3 To increase. As a result, the thermoelectric ratio Q decreases, and the thermoelectric demand ratio Q ′ = Te ′ / Te ′ between the actual power load Pe ′ and the actual heat load Te ′.
The system can be operated with the optimum thermoelectric ratio Q that matches Pe '. Further, an exhaust heat hot water boiler or an exhaust heat steam boiler can be used as the exhaust heat recovery heat exchanger 6, and the opening degree of the control valve 16 can be controlled by a temperature detection signal of the hot water or a vapor pressure detection signal of the generated steam. Are the same as in the first embodiment.

FIG. 3 shows a third embodiment of the present invention. The first embodiment and the second embodiment are combined.
This makes it possible to control the thermoelectric ratio Q of the system output with higher accuracy. That is, as shown in FIG. 3, the regenerator 3, the high temperature turbine exhaust gas G ₁ of the bypass passage 10 and provided with a bypass flow path 15 of the combustion air A, respectively control valves 11, 16 in each bypass flow path 10, 15 And by appropriately adjusting the opening of one or both of the control valves according to the fluctuation of the heat load 8, the thermoelectric ratio Q of the system output of the gas turbine cogeneration system can be compared with the actual power load 7 The thermoelectric demand ratio Q 'with the thermal load 8 enables the precision to be matched smoothly and naturally.

FIG. 4 is a schematic explanatory view of a gas turbine generator unit U used in the embodiment of the present invention, and includes a gas turbine 1, an air compressor 2, a regenerator 3, a combustor 4, a generator 5, and The air preheating pipe (passage) 2a, the high-temperature turbine exhaust gas pipe (passage) 9, the high-temperature turbine exhaust gas branch 9a, the air bearing 17, the generator cooling fin 18, the regenerator casing 19, and the turbine exhaust port 3c are integrally assembled. Thus, a gas turbine generator unit U is formed. Further, the gas turbine generator unit U includes:
It is placed on a single support frame together with other devices and housed in a package casing, mass-produced in a factory as a compact gas turbine cogeneration device, and then transported to an installation location.

FIG. 5 shows an example of the exhaust heat recovery heat exchanger 6 in the present embodiment, which is known as a vacuum type exhaust heat boiler. That is, the vacuum waste heat boiler, by the turbine exhaust gas G ₂ was heated boiler water (heat medium water) 6c, thereby together is evaporated to boiler water 6c, a water heating pipe 6a provided in vacuum vapor chamber 6d, the The hot water W in the hot water heating tube 6a is generated by the evaporation vapor of the can water 6c.
Is heated so that when there is no steam in the reduced-pressure steam chamber 6d, heat is not transferred from the hot water W side to the can water 6c side. In addition, 6b is a heat exchange tube.

A small-capacity gas turbine cogeneration system, which is one of the objects of the present invention, is often used by combining a plurality of such units in a parallel manner. There are many cases corresponding to. In such a case, for example, in a parallel operation of three systems, one of the systems is stopped and the other two are stopped.
If one system supplies hot water to the heat load,
In the case of using a normal waste heat hot water boiler, the heat of the waste heat hot water boiler of the operating system is transmitted through the hot water header to the can water (heat medium water) side of the waste heat hot water boiler that is not operating, This greatly increases the heat loss. On the other hand, in the case of the vacuum-type exhaust heat hot water boiler, as described above, the can water 6 is passed through the hot water heating pipe 6a of the system that is not in operation.
Since no heat is transmitted to the c side, a decrease in the thermal efficiency of the entire system is prevented, which is advantageous.

[0035]

Is In the present invention, the regenerator constituting the gas turbine cogeneration system, provided with either or both the bypass passage of the hot turbine exhaust gas G ₁ and the combustion air A, the bypass passage The thermoelectric ratio Q of the system output is made to match the actual thermoelectric demand ratio Q 'on the load side by appropriately adjusting the control valve provided in the system in accordance with the fluctuation of the thermal load. as a result,
As in the conventional gas turbine cogeneration system of this type, there is no difference between the thermoelectric ratio Q of the system output and the thermoelectric demand ratio Q 'on the load side, resulting in no surplus or insufficient heat. The gas turbine cogeneration system can always be operated at a high efficiency with the optimal system output thermoelectric ratio. The present invention has excellent practical utility as described above.

[Brief description of the drawings]

FIG. 1 is a block configuration diagram of a small-capacity gas turbine cogeneration system according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a small-capacity gas turbine cogeneration system according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a small-capacity gas turbine cogeneration system according to a third embodiment of the present invention.

FIG. 4 is a schematic explanatory view of a gas turbine generator unit used in the present invention.

FIG. 5 is a schematic explanatory view of an exhaust heat recovery unit used in the present invention.

FIG. 6 is a block diagram of a conventional gas turbine cogeneration system.

[Explanation of symbols]

1 is a gas turbine, 2 is a compressor, 3 is a regenerator, 3a · 3
b is a heat exchange tube, 3c is a turbine exhaust gas outlet, 4 is a combustor, 5 is a generator, 6 is an exhaust heat recovery heat exchanger, 6a is a hot water heating tube, 6b is a heat exchange tube, and 6c is can water (heat medium). Water, 6d is a reduced-pressure steam chamber, 7 is a power load, 8 is a heat load, 9 is a high-temperature turbine exhaust gas passage, 9a is a high-temperature turbine exhaust gas branch port, 1
0 bypass passage of the hot turbine exhaust gas G _1, the control valve 11, 12 is turbine exhaust gas passage, 13 cold water inlet pipe, 14 is the hot water outlet pipe, 15 a bypass passage of the combustion air, 16 a control valve, 17 is an air bearing, 1
8 generator cooling fan, the regenerator housing 19, U is the gas turbine generator unit, F is the fuel gas, A is the combustion air, G ₁ is the high-temperature turbine exhaust gas, G ₂ is the turbine exhaust gas, G ₀ is the exhaust gas, W ₁ is hot water, W ₂ is the low-temperature water, P
e is the electric output of the generator, Te is the heat output of the heat recovery heat exchanger, Te 'is the heat demand of the heat load, Pe' is the power demand of the power load, and Q is the thermoelectric ratio (Te / Pe). , Q ′ are thermoelectric demand ratios (Te ′ / Pe ′).

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F24H 1/00 631 F24H 1/00 631D

Claims (5)

[Claims] 1. A gas turbine, a generator, a compressor, a regenerator, a combustor, and an exhaust heat recovery heat exchanger, and high-temperature turbine exhaust gas from the gas turbine is supplied to the exhaust heat recovery heat exchanger via the regenerator. In the small-capacity gas turbine cogeneration system having the configuration described above, the regenerator is provided with a bypass passage for high-temperature turbine exhaust gas having a control valve, and the opening degree of the control valve according to the heat load of the exhaust heat recovery heat exchanger. A thermoelectric ratio control method for a small-capacity gas turbine cogeneration system, characterized in that the thermoelectric ratio of the system output is controlled by adjusting the thermoelectric ratio. 2. A small configuration comprising a gas turbine, a generator, a compressor, a regenerator, a combustor, and an exhaust heat recovery heat exchanger, and supplying combustion air from the compressor to the combustor via the regenerator. In a gas turbine cogeneration system having a capacity, a bypass passage for combustion air provided with a control valve is provided in the regenerator, and an opening degree of the control valve is adjusted according to a heat load of an exhaust heat recovery heat exchanger. A method for controlling a thermoelectric ratio of a small-capacity gas turbine cogeneration system, wherein the thermoelectric ratio of a system output is controlled. 3. A gas turbine, a generator, a compressor, a regenerator, a combustor, and an exhaust heat recovery heat exchanger, and high-temperature turbine exhaust gas from the gas turbine is supplied to the exhaust heat recovery heat exchanger via the regenerator. In a small-capacity gas turbine cogeneration system configured to supply combustion air from a compressor to a combustor via a regenerator, a bypass passage for high-temperature exhaust gas having a control valve in the regenerator and By providing a bypass passage for combustion air equipped with a valve and adjusting the opening of one or both of the control valves according to the heat load of the exhaust heat recovery heat exchanger, the thermoelectric ratio of the system output can be reduced. A method for controlling a thermoelectric ratio of a small-capacity gas turbine cogeneration system, the method comprising controlling. 4. A gas turbine generator unit by integrally assembling a gas turbine, a generator, an air compressor, a regenerator, and a combustor, and using a waste heat boiler or a vacuum type exhaust heat recovery heat exchanger. 4. The method according to claim 1, 2 or 3, wherein the waste heat hot water boiler is used. 5. A change in heat load is detected by detecting a still water temperature or a generated steam pressure of the exhaust heat recovery heat exchanger,
4. The thermoelectric ratio control of the small-capacity gas turbine cogeneration system according to claim 1, wherein the opening of the control valve is adjusted based on the detected can water temperature or the generated steam pressure. Method.