WO2012014401A1

WO2012014401A1 - Intermediate cooling device for gas turbine and gas turbine using same

Info

Publication number: WO2012014401A1
Application number: PCT/JP2011/004027
Authority: WO
Inventors: 亮宮前; 大野　達也; 前田　健一; 昌一高橋
Original assignee: 川崎重工業株式会社
Priority date: 2010-07-28
Filing date: 2011-07-14
Publication date: 2012-02-02
Also published as: JP2012031729A; JP5572471B2

Abstract

A gas turbine (1) comprises: multiple stage compressors (2, 3); a combustor (4) for injecting a fuel into air compressed by the compressors and combusting the fuel; and a turbine (5) driven by the combustion gas from the combustor. In the gas turbine, a heat exchanger (7) is installed between the compressor stages. The heat exchanger is used for heating the working gas of a Stirling engine (8) serving as an intermediate cooling device and is disposed in a flow path of compressed air compressed by the compressors to directly exchange heat between the compressed air and the working gas. This makes it possible to effectively use the waste heat of the gas turbine and to provide a relatively small-type and light weight intermediate cooling device, the leakage failure of which even does not pose a problem to the operation of the gas turbine. In the case of an aircraft gas turbine, a low-temperature-side heat exchanger (11) of the Stirling engine is disposed so that a low temperature atmosphere passes therethrough.

Description

Gas turbine intermediate cooling device and gas turbine using the same

The present invention relates to an intermediate cooling device interposed in the middle stage of a compressor of a gas turbine, and more particularly to a structure of an intermediate cooling device suitable for a gas turbine that is required to be reduced in size and weight, such as an aircraft engine.

Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-193910 and Japanese Patent Application Laid-Open No. 2006-220150, an intermediate cooler is interposed in the middle stage of the compressor in order to reduce the compression work of the gas turbine. Are well known, and there are many examples already in practical use in stationary systems such as plants. The intercooler can also be used as a relatively low-temperature heat source, and it has already been proposed to use it in ancillary facilities such as building heating, hot water supply, and a hot water pool.

In recent years, various efforts have been made in the aircraft industry to reduce fuel consumption due to rising oil-related fuel prices in addition to rising environmental awareness, and aircraft gas turbines (so-called jet engines, etc.) Are also studying technological innovations to reduce fuel consumption.

For example, if an intercooler such as that described above can be employed, the pressure ratio of the compressor can be improved even in an aircraft gas turbine, and the reduction of fuel consumption and output can be improved by reducing the compression work. There are various merits such that the high-temperature portion of the turbine can be effectively cooled by the later air.

However, in general, in aircraft applications, it has been the most important issue to be small and light, and there is no example of providing an intermediate cooler in a compressor of a gas turbine. In addition, when the intermediate cooler is viewed as a heat source as described above, the use is limited to relatively low-temperature ones such as heating and hot water supply. From this point of view as well, intermediate gas turbines for aircraft use intermediate cooling. It was common sense not to attach equipment that would increase the size and weight of the container.

Further, in the intercooler of the stationary gas turbine as in the conventional example, since the heat exchanger for circulating the cooling water is interposed in the middle stage of the compressor, the cooling water is temporarily leaked from the heat exchanger. When such a failure occurs, the cooling water is transported to the combustor together with the compressed air, and there is a possibility that the combustion deteriorates and thus misfires. From this point, the intercooler can be said to be suitable for a stationary gas turbine in which a heavy and heavy heat exchanger can be installed.

In view of these points, an object of the present invention is to provide an intermediate cooling device that can be effectively used as a heat source, is relatively small and lightweight, and does not cause a problem in the operation of a gas turbine even if a leakage failure occurs. There is to do.

In order to achieve the above object, the present invention combines a gas turbine with a Stirling engine and uses a high-temperature side heat exchanger through which the working gas of the Stirling engine flows as an intermediate cooler in the middle stage of the compressor. Is.

That is, the present invention is a gas comprising a multi-stage compressor, a combustor that injects and burns fuel into the compressed air, and a turbine that is driven by the combustion gas from the combustor. An intermediate cooling device provided in a turbine and having a heat exchanger in the middle of the compressor is an object. And as said heat exchanger, the heat exchanger of the high temperature side which heats the working gas of a Stirling engine is utilized, and this heat exchanger is arrange | positioned in the flow path of the compressed air of the said compressor.

In the gas turbine provided with the intermediate cooling device having the above-described configuration, the compressed air is cooled in the middle stage of the compressor by the heat exchanger, so that the pressure ratio is improved and the fuel consumption is reduced and the output is reduced by reducing the compression work. Improvement and the like. Moreover, it becomes possible to cool the high temperature part etc. of a turbine effectively with the cooled air.

Furthermore, since the heat exchanger is disposed in the compressed air flow path of the compressor, the working gas of the Stirling engine can be effectively heated. By driving, for example, an auxiliary machine or a generator of the gas turbine by the Stirling engine, the overall thermal efficiency of the gas turbine is improved.

Since the Stirling engine is a relatively small, light and highly efficient engine, the weight increase by adding this is small. Moreover, even if the working gas leaks from the heat exchanger and is transported to the combustor, it does not cause a big problem like cooling water. From this point, it is preferable to use a nonflammable gas such as helium gas as the working gas of the Stirling engine.

In other words, according to the intermediate cooling device using the Stirling engine according to the present invention, it is possible to effectively use the heat recovered from the compressed air of the gas turbine as energy, and it is relatively small and lightweight and suitable for aircraft applications. Even if a malfunction occurs in which the working gas leaks, the operation of the gas turbine is not hindered.

The heat exchanger has a flow path of compressed air so as to directly exchange heat between the working gas of the Stirling engine and the compressed air of the compressor via a heat transfer wall, for example, a plate or fin of the heat exchanger. You may arrange | position in. By directly exchanging heat in this way, the working gas of the Stirling engine can be effectively heated.

As a preferred embodiment, when the compressor of the gas turbine is of an axial flow type provided with an inner peripheral rotor that supports the moving blades and an outer peripheral case that supports the stationary blades, The heat exchanger may be provided in an annular shape over the entire flow path of the compressed air between the rotor and the case of the compressor. Further, at least one piston / cylinder of the Stirling engine may be disposed on the outer peripheral side of the case. In this way, existing gas turbines can be installed while suppressing an increase in size and weight without major design changes.

Further, if the Stirling engine has a plurality of pistons / cylinders, the plurality of pistons / cylinders may be arranged at intervals in the circumferential direction. In this case, among the plurality of pistons / cylinders, adjacent ones may be connected via a regenerator to form a so-called backward acting (double acting type) Stirling engine. This is advantageous for further miniaturization, weight reduction and high output.

Thus, an intermediate cooling device using a small, lightweight and highly efficient Stirling engine is suitable for an aircraft gas turbine. In the case of an aircraft, since the outside air temperature during flight is considerably low, the heat exchanger on the low temperature side for cooling the working gas may be arranged to exchange heat with the atmosphere. By doing so, the temperature difference between the high temperature side and the low temperature side is increased, and the efficiency of the Stirling engine can be further increased.

For example, if the gas turbine is a turbo fan or the like in which a fan is provided in front of the compressor, the low-temperature side heat exchanger may be housed in a fan case through which exhaust from the fan circulates. By adjusting the flow rate of the exhaust gas to the heat exchanger, the temperature of the working gas on the low temperature side can be changed and the output of the Stirling engine can be controlled.

Further, the present invention can be applied not only to aircraft gas turbines but also to marine and industrial gas turbines. In many cases, gas turbines for ships are diverted to aircraft, and the advantages of miniaturization and weight reduction are great. Of course, even if operating gas leaks from the heat exchanger on the high temperature side, the gas turbine can be operated. It is also important from the viewpoint of ensuring the operation of the ship as well as the aircraft that it will not interfere.

In particular, when liquefied gas fuel is used for the operation of the gas turbine, a heat exchanger on the low temperature side may be disposed so as to exchange heat between the liquefied gas fuel and the working gas. In this way, the temperature difference from the high temperature side becomes very large, and not only the efficiency of the Stirling engine is remarkably increased, but also the waste heat from the Stirling engine is effectively used as a heat source for vaporizing the liquefied gas fuel. Can do.

In other words, the present invention includes a multi-stage compressor, a combustor that injects and burns fuel into the compressed air, and a turbine that is driven by combustion gas from the combustor. A gas turbine comprising an intermediate cooling device as described above (according to the inventions of claims 1 to 6 described later) with a heat exchanger interposed in the middle stage of the compressor. To do.

As described above, according to the gas turbine intermediate cooling apparatus according to the present invention, in view of the characteristics of the Stirling engine that is small, light, and highly efficient, the high-temperature side heat exchanger that heats the working gas is provided with the intermediate cooling of the gas turbine. By using as a compressor, the heat recovered from the middle stage of the compressor of the gas turbine can be effectively used as energy. Further, even if the working gas leaks from the heat exchanger, it does not hinder the operation of the gas turbine, and is suitable for an aircraft or marine gas turbine.

1 is a system diagram of a gas turbine according to an embodiment of the present invention and a Stirling engine that is an intermediate cooling device thereof. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing a first embodiment applied to an aircraft turbofan engine in a plane including an axis of a compressor and a turbine. It is explanatory drawing which shows typically arrangement | positioning of the heat exchanger in the middle stage of a compressor. It is explanatory drawing of operation | movement of a Stirling engine. It is a PV diagram of a Stirling cycle. It is FIG. 2 equivalent view which concerns on 2nd Embodiment applied to the gas turbine for ships.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram of a gas turbine and a Stirling engine according to the embodiment. FIG. 2 shows a first embodiment in which the gas turbine is applied more specifically to a turbofan engine for an aircraft. FIG. 3 schematically shows the arrangement of heat exchangers in the middle stage of the compressor.

As schematically shown in the lower side of FIG. 1, the multistage gas turbine 1 includes an intermediate pressure compressor 2 and a high pressure compressor 3 that suck in (intake) and compress air, respectively, and compress the air by using these. While supplying high-temperature and high-pressure air to the combustor 4, fuel is injected into the combustor 4 and burned. And while driving the turbine 5 with the combustion gas from the combustor 4, a part of combustion gas is ejected back as a jet jet, and thrust is obtained. In the illustrated example, the turbine 5 is also provided with a front-stage high-pressure turbine 5a and a rear-stage intermediate-pressure turbine 5b, which drive the high-pressure compressor 3 and the intermediate-pressure compressor 2 via

shafts

6a and 6b, respectively.

Further, a heat exchanger 7 is provided between the intermediate pressure compressor 2 and the high pressure compressor 3, and heat is taken away from high-temperature air of about 200 to 400 ° C. compressed by the intermediate pressure compressor 2. , Function as an intercooler to cool this. The heat exchanger 7 is a heat source for heating the working gas (preferably helium gas) of the Stirling engine 8 shown in the upper side of FIG. 1, and is disposed in the compressed air flow path as described below. The compressed air and the working gas of the Stirling engine 8 are directly heat exchanged.

The Stirling engine 8 is a double-acting type (double-acting type) provided with a plurality of pistons / cylinders as an example, and two cylinders 9 connected to each other are basically arranged on the upper side of FIG. Illustration of other pistons / cylinders is omitted. Although the piston / cylinder operation will be described in detail later, the internal space of each cylinder 9 is divided into two in the longitudinal direction by the piston 10, and one space 9 a communicates with the other space 9 b of another cylinder 9 adjacent thereto. Yes.

As described above, the high-temperature side heat exchanger 7 interposed in the middle stage of the

compressors

2 and 3 of the gas turbine 1 is connected to one space 9a (hereinafter referred to as a high-temperature space) of each cylinder 9. The working gas in the high temperature space 9a is heated. On the other hand, the other space 9b (hereinafter referred to as a low temperature space) of each cylinder 9 is connected to a low temperature side heat exchanger 11 for exchanging heat with a low temperature atmosphere (cold heat source) as will be described later.

The pistons 10 of the cylinders 9 are connected to the crankshaft 12 by connecting rods 10a, and reciprocate with a phase shift. As a result, the working gas moves through the regenerator 13 between the high temperature space 9 a and the low temperature space 9 b communicated as described above, and a rotational force is output from the crankshaft 12.

The output from the crankshaft 12 is used, for example, to drive a generator (not shown) or an auxiliary machine of the gas turbine 1. The Stirling engine 8 has a simple structure, can be reduced in size and weight, is excellent in silence and reliability, and is particularly suitable for use in an aircraft gas turbine. Further, the thermal efficiency of the Stirling engine 8 is theoretically the same as that of the Carnot cycle, and is extremely high. By using this, the overall thermal efficiency of the gas turbine 1 can be improved.

-gas turbine-
In the first embodiment shown in FIG. 2, the gas turbine 1 is an aircraft turbofan engine 100. As shown at the left end of the figure, a large fan 102 is accommodated near the front end portion of the fan case 101 of the turbofan engine 100 and is driven by the turbine 5 via a shaft (not shown). The fan 102 functions as a low-pressure compressor, and sends out air (outside air) taken into the fan case 101 backward (to the right in the figure) while compressing it.

Most of the airflow from the fan 102 (about 90% as an example) flows between the fan case 101 and the duct component 103 on the inner peripheral side thereof, that is, in the duct 104 having an annular cross section, and has an intermediate pressure. A relatively low-speed exhaust jet that bypasses the compressor 2 and the like is ejected to the rear of the fan case 101. On the other hand, a part of the air flow from the fan 102 is taken into the intermediate pressure compressor 2 and used for combustion in the combustor 4. Thus, in the high bypass ratio turbofan engine 100 in which most of the airflow from the fan 102 is ejected rearward as it is, the reactive energy of the exhaust jet is reduced, which is advantageous in reducing fuel consumption.

The intermediate pressure compressor 2 is an axial-flow multistage compressor in this example, and includes a drum 20 (rotor) that supports a plurality of stages (five stages in the illustrated example) of moving blades 21 and an outer periphery of the drum 20. , And a compressor case 22 that supports the stationary blades (not shown) so as to be alternately arranged before and after the moving blades 21. As described above, the air flow sent from the fan 102 to the intermediate pressure compressor 2 is compressed while passing between the stationary blades and the moving blades 21 of each stage, and between the drum 20 and the compressor case 22. The cross-section annular compression channel is fed backward. The cross-sectional area of the compression flow path gradually decreases from the front to the rear so as to correspond to the compression ratio of air.

The air that has been compressed by the intermediate pressure compressor 2 to a high temperature (for example, about 200 to 400 ° C.) is heat that is provided over the entire cross section of the compression flow path as schematically shown in FIG. After passing through the exchanger 7 and once cooled, it is taken into the high-pressure compressor 3. The high-pressure compressor 3 is a multistage compressor having substantially the same structure as the intermediate-pressure compressor 2, and the temperature of the compressed air is circulated between the drum 30 that supports the moving blade 31 and the compressor case 32. And the pressure rises further. Then, air in a predetermined high temperature and high pressure state is supplied to the combustor 4.

As an example, the combustor 4 is a so-called annular combustor, and a detailed description thereof will be omitted, but the annular combustion chamber surrounded by the inner cylinder wall and the outer cylinder wall is inserted into the annular combustion chamber at one end in the cylinder axis direction. In this way, high-temperature and high-pressure air is supplied. Then, fuel is injected from a fuel injection nozzle facing the combustion chamber in the vicinity of the entrance, mixed with the high-temperature and high-pressure air, and burned well. In the combustor 4, secondary air and tertiary air are further supplied to the combustion gas to achieve complete combustion, and the combustion gas is diluted and adjusted to an appropriate temperature and ejected backward from the combustor outlet. Is done.

The turbine 5 that receives the jet of combustion gas is an axial-flow turbine having a plurality of stages including stationary blades and moving blades, similar to the intermediate pressure compressor 2 and the high pressure compressor 3. In addition to the high-pressure turbine 5a and the intermediate-pressure turbine 5b in the subsequent stage, a low-pressure turbine 5c for driving the fan 102 is provided in the last stage. Although not shown, the shaft connecting the fan 102 and the low-pressure turbine 5c is inserted coaxially into the

hollow shafts

6a and 6b that are coaxially arranged with each other.

Then, after driving the high-pressure turbine 5a, the intermediate-pressure turbine 5b, and the low-pressure turbine 5c and driving the high-pressure compressor 3, the intermediate-pressure compressor 2, and the fan 102 through these, the high-temperature and high-pressure states are further increased. The maintained combustion gas is converted into kinetic energy from the internal energy (thermal energy) in the exhaust nozzle 105, and is jetted backward as a high-speed jet.

Incidentally, as described above, the heat exchanger 7 functioning as an intermediate cooler is interposed between the intermediate pressure compressor 2 and the high pressure compressor 3. As shown in FIG. 2, the heat exchanger 7 is disposed over the entire cross section of the compression flow path between the inner periphery side drum 20 and the vicinity of the rear end portion of the compressor case 22. That is, as shown schematically in FIG. 3, when viewed in the direction of the axial center of the

compressors

2, 3 and the turbine 5, there are eight struts 23 between the inner drum 20 and the compressor case 22. The heat exchanger units 70 are arranged one by one in eight regions that extend radially and are thus divided in the circumferential direction.

The heat exchanger unit 70 is, for example, a plate fin type (may be a tube fin type tube type or the like), and the working gas of the Stirling engine 8 flowing through the flow path between the plates is a heat transfer wall. Heat is exchanged directly with the compressed air through the plate and corrugated fins. In this way, heat exchange efficiency is high because heat exchange is performed directly without interposing a refrigerant.

Further, the eight cylinders 9 of the Stirling engine 8 are arranged in the circumferential direction at intervals from each other on the outer peripheral side of the

compressor cases

22 and 32 corresponding to the respective heat exchanger units 70. In this example, as shown in FIG. 2, the cylinder 9 is disposed in a structural space between the compressor case 32 and the duct component 103. One end (left end in FIG. 2) in the longitudinal direction of each cylinder 9 is connected to the corresponding heat exchanger unit 70 via the high temperature side pipe 9c (see FIG. 1).

Although only one high temperature side pipe 9c is schematically shown in the figure, the high temperature side pipe 9c is actually composed of a plurality of pipes, and each cylinder 9 has an entire bowl-shaped portion at its end. Connected. The same applies to the low temperature side pipe 9d described below.

That is, a low temperature side pipe 9d (see FIG. 1) is connected to the other end (right end in FIG. 2) in the longitudinal direction of each cylinder 9, and the opposite end of the low temperature side pipe 9d is a low temperature of the Stirling engine 8. It is connected to the side heat exchanger 11. As shown in FIG. 2, the heat exchanger 11 on the low temperature side is accommodated in the fan case 101, and low temperature air flowing through the duct 104 passes therethrough. Although not shown in detail, the low temperature side heat exchanger 11 is also composed of a plurality of units arranged at intervals in the circumferential direction of the cross section of the duct 104, and the air flow from the fan 102 flows between these units with low resistance. It is possible.

In the present embodiment, a flow rate adjusting member 106 such as a movable vane for guiding the air flow from the fan 102 is provided upstream of the low-temperature heat exchanger 11. The flow rate adjusting member 106 is operated by an actuator (not shown), and distributes the air flow from the fan 102 to each unit of the low temperature side heat exchanger 11 and a flow path between them, thereby providing a low temperature side heat exchanger. 11 functions as a flow rate adjusting means for adjusting the flow rate of the air to the air outlet 11. By adjusting the air flow rate, output control of the Stirling engine 8 can be performed.

-Stirling organization-
As described above with reference to FIG. 3, the Stirling engine 8 of the present embodiment has eight pistons / cylinders arranged in the circumferential direction on the outer peripheral side of the compressor case 32 and is shown only in FIG. A high temperature space 9a and a low temperature space 9b between the two cylinders 9 are communicated by a communication pipe 9e, and a regenerator 13 is interposed in the middle. The pistons 10 of the two cylinders 9 reciprocate with a phase difference of approximately 90 degrees, and as a result, the working gas moves between the high temperature space 9a and the low temperature space 9b as described below.

In other words, the Stirling engine 8 of the present embodiment is basically an α-type engine composed of two pistons / cylinders, and further, the two working spaces are formed by the piston 10 in one cylinder 9, thereby reducing the size and weight. Is intended. By combining four pistons / cylinders each having two working spaces with a phase difference of 90 degrees, four α-type Stirling engines can be configured. In this embodiment, eight pistons / cylinders can provide eight outputs.

Hereinafter, the operation and thermal cycle of the Stirling engine 8 will be described in detail with reference to FIG. 4 and FIG. In FIG. 4A to FIG. 4F, the low temperature space 9b on the right side of the upper cylinder 9 communicates with the high temperature space 9a of another cylinder 9 (not shown). The space 9 a is also communicated with a low temperature space 9 b of another cylinder 9. However, only the operation of the engine by the high temperature space 9a of the upper cylinder 9 and the low temperature space 9b of the lower cylinder 9 will be described here for convenience.

First, in FIG. 4A, the piston 10 of the upper cylinder 9 and the piston 10 of the lower cylinder 9 are substantially at the same position, but the phases of both are substantially 90 degrees apart. On the other hand, the lower cylinder 9 is past the high temperature side dead center. Due to the operation of the general crank structure, the operation of the piston 10 from slightly before the dead center to past the dead center becomes very small.

4 between A and B in FIG. 4, the crankshaft 12 rotates about 90 degrees, and the upper cylinder 9 reaches the same position as the lower cylinder 9 in FIG. During this time, the piston 10 of the upper cylinder 9 is in the vicinity of the high temperature side dead center and does not operate much, while the piston 10 of the lower cylinder 9 operates largely from the vicinity of the high temperature side dead center toward the low temperature side. . Meanwhile, in the lower cylinder 9, the working gas is compressed in the low temperature space 9b while keeping the temperature substantially constant (isothermal compression). That is, on the PV line in FIG. 5, the state changes from state 1 to state 2, and heat is radiated as indicated by arrows.

Subsequently, the crankshaft 12 is also rotated by 90 degrees between B and C in FIG. 4, whereby the piston 10 of the upper cylinder 9 moves from the vicinity of the high temperature side dead center toward the low temperature side, and the lower cylinder. 9, the piston 10 operates from approximately the center of the stroke to just before the low temperature side dead center at the right end of the drawing. That is, the two pistons 10 are operated substantially synchronously, whereby the working gas moves from the low temperature space 9b of the lower cylinder 9 where the volume decreases to the high temperature space 9a of the upper cylinder 9 where the volume increases. At this time, the working gas is heated by passing through the regenerator 13 (isothermal heating) and absorbs heat in the state 2 to the state 3 in FIG.

Subsequently, the crankshaft 12 also rotates about 90 degrees between C and D in FIG. 4, but this time the piston 10 of the lower cylinder 9 near the low temperature side dead center does not operate much, In the cylinder 9, the piston 10 moves greatly from the approximate center of the stroke to just before the low temperature side dead center. In the high-temperature space 9a of the upper cylinder 9, the heated working gas expands (isothermal expansion) while keeping the temperature substantially constant, and absorbs heat as indicated by arrows in the state 3 to the state 4 in FIG.

And between D and E in FIG. 4, the piston 10 of the upper cylinder 9 near the low temperature side dead center does not operate much again, while the piston 10 of the lower cylinder 9 moves from the vicinity of the low temperature side dead center to the high temperature side. Operates greatly toward. Further, between E and 4F in FIG. 4, the piston 10 of the upper cylinder 9 operates from the vicinity of the low temperature side dead center toward the high temperature side, and the piston 10 of the lower cylinder 9 reaches before the high temperature side dead center. . From here to the above-described FIG. 4A, the piston 10 of the upper cylinder 9 reaches the high temperature side dead center, and the piston 10 of the lower cylinder 9 is in the vicinity of the high temperature side dead center.

When viewed through D → E → F → A in FIG. 4, the piston 10 operates from the vicinity of the low temperature side dead center to the vicinity of the high temperature side dead center in both the upper and lower cylinders 9. It is pushed out of the high temperature space 9a, cooled when passing through the regenerator 13, and moved to the low temperature space 9b of the lower cylinder 9. That is, the working gas is cooled at the same volume while dissipating heat as indicated by arrows in the state 4 to the state 1 in FIG.

Thus, during one and a half rotations of the crankshaft 12, one cycle of the Stirling cycle as shown in FIG. 5 is performed in the high temperature space 9a and the low temperature space 9b in which the two adjacent cylinders 9 communicate with each other. Then, a generator and an engine accessory connected to the rotating crankshaft 12 are driven. That is, by cooling the compressed air between the

compressors

2 and 3 of the turbofan engine 100, and performing power generation and supplementary driving using the waste heat, overall thermal efficiency can be improved.

As described above, according to the turbofan engine 100 according to the first embodiment described above, the high temperature side heat exchanger 7 for heating the working gas is combined with the relatively small, light and highly efficient Stirling engine 8. Since the compressed air is cooled by interposing between the pressure compressor 2 and the high pressure compressor 3, the pressure ratio can be improved to reduce fuel consumption by reducing compression work, improve output, etc. realizable. A part of the cooled compressed air can be used for cooling a high-temperature part such as a moving blade of the turbine 5.

In addition, the high temperature side heat exchanger 7 can be accommodated in a compressed air flow path between the intermediate pressure compressor 2 and the high pressure compressor 3, and the size and weight of the engine can be increased even if the piston / cylinder of the Stirling engine 8 is included. The increase is not very large. It is possible to add without making a major design change based on the existing engine. Moreover, since the working gas which flows through the flow path between the plates of the high temperature side heat exchanger 7 directly exchanges heat with the compressed air, the efficiency of heat exchange is also high.

On the other hand, the low-temperature side heat exchanger 11 that cools the working gas is housed in the fan case 101 and directly exchanges heat between the low-temperature air flowing through the duct 104 and the working gas. If the outside air is high, the temperature becomes minus 40 ° C., and the temperature difference from the high temperature side heat exchanger 7 becomes large. Therefore, the advantage of the Stirling engine 8 that the thermodynamic cycle efficiency increases as the temperature difference between the high temperature side and the low temperature side increases can be maximized.

Furthermore, even if the working gas leaks from the heat exchanger 7 and is transported to the combustor 4, it is a non-combustible helium gas, so that it causes a serious problem such as misfire in the combustor 4. Absent. This is important to ensure aircraft operation.

-Second Embodiment-
FIG. 6 shows a second embodiment applied to a marine gas turbine 110. In addition, about the structure which is common in 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. In the example shown in the figure, the gas turbine 110 is an aeroderivative type that is small, light, and has high output, and the basic structure of a so-called gas generator such as the intermediate pressure compressor 2, the high pressure compressor 3, the turbine 5, and the like has been described above. It is the same as that of the first embodiment. However, in the gas turbine 110, the fan 102 is not disposed in front of the intermediate pressure compressor 2, and instead, the output shaft 6 is connected to the low pressure turbo 5c so that the driving force can be taken out. . In addition, what is shown as a code | symbol 24 in a figure is the moving blade arrange | positioned in the front | former stage of the intermediate pressure compressor 2, and rotates integrally with the drum 20 and the moving blade 21. FIG. The entire amount of air from here is supplied to the intermediate pressure compressor 2.

In addition, since the dimensional restrictions are loose compared with those for aircraft, in the example shown in the figure, a can-type combustor that can be easily replaced and maintained is used. That is, a plurality of combustion cylinders 40 are arranged radially so as to surround the shafts of the

compressors

2, 3 and the turbine 5. Fuel is injected from a fuel injection nozzle 41 individually disposed in the combustion cylinder 40 and burned. The combustion gas is ejected from the combustion cylinder outlet provided at the inner peripheral end of the combustion cylinder 40 so as to be deflected toward the turbine 5 and supplied to the turbine 5.

As the fuel supplied to the fuel injection nozzle 41 of the combustion cylinder 40, liquefied natural gas (LNG) is used as an example. LNG is stored in a high-pressure tank 42 in a liquid state, and is warmed and gasified as necessary, and is pressurized to a predetermined pressure by the fuel pump 43 and supplied to the fuel injection nozzle 41. As will be described later, in this embodiment, the heat exchanger 11 on the low temperature side of the Stirling engine 8 is used as a heat source for warming the LNG.

Furthermore, in the gas turbine 110 of this embodiment, the turbine 5 that receives the combustion gas from the combustor 4 also has a different part from that of the first embodiment. The high-pressure turbine 5a at the front stage and the intermediate-pressure turbine 5b at the rear stage drive the high-pressure compressor 3 and the intermediate-pressure compressor 2, respectively. A part of the driving force of the intermediate-pressure compressor 2 is decelerated by the gear train and is compressed at low pressure. Used to drive the machine 111. Further, the output shaft 6 extends rearward from the last-stage low-pressure turbine 5c, and drives a ship screw or a generator for rotating the screw via a speed reducer or the like. Yes.

The combustion gas after driving the low-pressure turbine 5c that performs the work for driving the screw does not leave enough internal energy to become a jet jet like an aircraft engine. The turbine 110 is not provided with the exhaust nozzle 105. Exhaust gas from the low-pressure turbine 5c may be discharged from a chimney or the like after being sent to a reheater (not shown) to recover waste heat. If the waste heat collected in the reheater is used to reheat the compressed air of the high-pressure compressor 3, the heat utilization efficiency is further enhanced in combination with intermediate cooling, which is preferable.

And in the gas turbine 110 of this embodiment, the high temperature side heat exchanger 7 of the Stirling engine 8 which is an intermediate cooling device is the same between the intermediate pressure compressor 2 and the high pressure compressor 3 as in the first embodiment described above. It is disposed across the entire annular cross section in the flow path of the compressed air. On the other hand, the heat exchanger 11 on the low temperature side is arranged so that the LNG supplied to the combustor 4 passes as schematically shown in FIG. 6, and the working gas of the Stirling engine 8 and the cryogenic LNG Heat exchange.

That is, in the fuel supply system for supplying LNG to each combustion cylinder 40 of the combustor 4, the high temperature side heat exchanger 7 is interposed in the LNG supply line 44 from the high pressure tank 42 to the fuel pump 43. The working gas is effectively cooled and the LNG is effectively warmed. Thus, by using the cryogenic LNG, the temperature difference between the high temperature side and the low temperature side in the Stirling engine 8 becomes very large, and the efficiency becomes extremely high. Moreover, the waste heat from the Stirling engine 8 is also effectively used.

Therefore, also in the marine gas turbine 110 according to the second embodiment, effects such as improvement of the pressure ratio, reduction of compression work, and improvement of output can be obtained by the intermediate cooling as in the first embodiment. Further, since the recovered heat is used as a heat source and the extremely low temperature LNG is used as a cold heat source, the efficiency of the Stirling engine 8 becomes very high, and the overall heat efficiency of the gas turbine 110 is improved. Even if the working gas leaks, the operation of the gas turbine 110 is not hindered and the operation of the ship can be ensured.

-Other embodiments-
The first and second embodiments described above are merely illustrative in nature, and are not intended to limit the present invention, its application, or its use. For example, in the first embodiment, the case where the present invention is applied to a turbofan engine 100 with a high bypass ratio and excellent fuel efficiency as an aircraft gas turbine has been described. You may apply to an engine, a turboprop engine, or you may apply to a turbojet engine.

When applied to a turboprop engine or a turbojet engine, the fan case 101 as in the first embodiment is not provided, so the low temperature side heat exchanger 11 of the Stirling engine 8 covers the outer periphery of the engine case. It may be accommodated in such a dedicated case and arranged so that the outside air passes therethrough.

On the other hand, the heat exchanger 7 on the high temperature side of the Stirling engine 8 does not depend on the kind of the gas turbine as described above, and the drum (rotor) on the inner peripheral side in the middle stage of the compressor as in the above embodiments. You may arrange | position over the whole cross section of the compression flow path between cases on the outer peripheral side, and you may arrange | position not only to this but to a part of cross section of the compression flow path, for example.

Further, in each of the above-described embodiments, the

compressors

2 and 3 and the turbine 5 of the gas turbine 1 are all axial flow types, but are not limited to this, and for example, a centrifugal compressor or a radial turbine is used. The present invention may be applied to a gas turbine provided.

Also, the Stirling engine 8 is not limited to the structure and arrangement described in the above embodiments. For example, the number of pistons / cylinders may not be eight, and they may be arranged on the outer peripheral side of the compressor case 32. There is no need to arrange them. Further, the Stirling engine 8 is not limited to the reciprocating type Stirling engine 8, but the basic two-piston type (α type), displacer type (β type and γ type), and free piston type can be used. Can be used.

Furthermore, in the second embodiment, the case where the LNG is used as a fuel and applied to the aeroderivative marine gas turbine 110 has been described. However, a liquefied gas fuel other than LNG may be used. The present invention can also be applied to a marine gas turbine 110 using various fuels. When liquefied gas fuel is not used, the low temperature side heat exchanger 11 of the Stirling engine 8 may be provided so that, for example, seawater circulates, and the working gas can be effectively cooled by the low temperature seawater.

The intermediate cooling device of the present invention may be applied to a so-called industrial gas turbine. In this case, the structure of the gas turbine is the same as that of the ship of the second embodiment. This is similar to the industrial gas turbine 110.

The intermediate cooling device for a gas turbine according to the present invention uses a small, lightweight and highly efficient Stirling engine, can effectively use the recovered heat, and can interfere with the operation of the gas turbine even in the event of a leakage failure. This is particularly suitable for aircraft use.

Claims

Provided in a gas turbine comprising a multi-stage compressor, a combustor that injects and burns fuel into compressed air, and a turbine driven by combustion gas from the combustor, In the intercooling device comprising a heat exchanger in the middle of the compressor,
The heat exchanger is a high-temperature side heat exchanger that heats the working gas of the Stirling engine, and is disposed in a flow path of compressed air of the compressor. apparatus.
The heat exchanger is disposed in the flow path of the compressed air so that the working gas of the Stirling engine and the compressed air of the compressor exchange heat directly via a heat transfer wall. The intermediate cooling device according to claim 1.
The compressor is of an axial flow type provided with an inner peripheral rotor that supports the moving blades and an outer peripheral case that supports the stationary blades,
The heat exchanger is provided in an annular shape over the entire flow path of compressed air between the rotor and the case of the compressor,
The intermediate cooling device according to claim 1, wherein at least one piston / cylinder of the Stirling engine is disposed on an outer peripheral side of the case.
The gas turbine is for aircraft;
The intermediate cooling device according to claim 1, wherein the Stirling engine is disposed such that a low-temperature heat exchanger for cooling the working gas comes into contact with the atmosphere.
The intermediate cooling device according to claim 4, wherein a fan is provided in a front stage of the compressor, and the low-temperature side heat exchanger is accommodated in a fan case through which exhaust from the fan circulates.
The gas turbine uses liquefied gas fuel;
The intermediate cooling device according to claim 1, wherein the heat exchanger on the low temperature side of the Stirling engine is arranged to exchange heat between the working gas and the liquefied gas fuel.
A multi-stage compressor, a combustor that injects and burns fuel into the compressed air, and a turbine that is driven by combustion gas from the combustor;
A gas turbine, wherein the intermediate cooling device according to claim 1 is provided with a heat exchanger interposed in the middle stage of the compressor.