JP2003331856A - Electric power generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To activate a solid electrolyte fuel cell by effectively utilizing the exhaust heat from a combustion chamber of a gas turbine engine in an electric power generator equipped with the gas turbine engine and the solid electrolyte fuel cell in one body. <P>SOLUTION: This electric power generator is equipped with the gas turbine engine GT and the solid electrolyte fuel cell FC in one body, a heat exchanger 20, the combustion chamber 27, and the solid electrolyte fuel cell FC are arranged on a shaft line of a rotation part 33 comprising a compressor wheel 17 and a turbine wheel 18, and the solid electrolyte fuel cell FC is arranged so as to surround the outside in the radius direction of the combustion chamber 27, and thereby, the solid electrolyte fuel cell FC is activated from the initial stage of starting by using the exhaust heat from the combustion chamber 27 and in addition, the heat is recovered with the solid electrolyte fuel cell FC to enhance the power generation efficiency. By operating the combustion chamber 27 only at the start of the gas turbine engine GT, operation of the combustion chamber 27 requiring large fuel consumption is minimized. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generator that integrally includes a gas turbine engine and a solid oxide fuel cell.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 2001-516935 discloses a hybrid electric power system in which a turbomachine and a fuel cell are combined. The turbomachine drives the generator by rotating the power turbine with the high-pressure gas generated by burning the fuel in the combustor to generate electricity, and the fuel cell passes through the compressor and recuperator of the turbomachine to heat the heated air. And react with fuel to generate electricity.

US Pat. No. 6,213,234 discloses that
A vehicle with a fuel cell and a generator driven by a gas turbine engine is described. By supplying less than about 50% of the maximum electric power required to drive the vehicle from the fuel cell, it is possible to reduce the fuel consumption without enlarging the fuel cell inevitably and when the electric power required by the vehicle is small. In addition, fuel cells efficiently supply all or most of the required power.

US Pat. No. 6,255,010 describes
It describes that a power generation device including a gas turbine engine, a fuel cell and a generator is housed in a common pressure vessel and operated in a pressurized state.

[0005]

By the way, in a power generator having a gas turbine engine and a solid oxide fuel cell integrally, a solid oxide fuel cell utilizing waste heat generated by a combustor of the gas turbine engine. When activating the exhaust gas, it is difficult to effectively utilize the waste heat by disposing the gas turbine engine and the solid oxide fuel cell apart from each other or simply combining the fuel cell with the gas turbine engine. .

The present invention has been made in view of the above-mentioned circumstances, and in a power generator having a gas turbine engine and a solid oxide fuel cell integrated, the waste heat of the combustor of the gas turbine engine is effectively used. The purpose is to activate a solid oxide fuel cell.

[0007]

In order to achieve the above object, according to the invention described in claim 1, there is provided a power generation device integrally including a gas turbine engine and a solid oxide fuel cell, The gas turbine engine includes a compressor wheel, a turbine wheel, a heat exchanger and a combustor, the compressor wheel supplies compressed air to the solid oxide fuel cell and the combustor through the heat exchanger, and the turbine wheel is a solid oxide fuel. The heat exchanger, the combustor, which drives the compressor wheel driven by the exhaust gas from the battery and the combustor, and the heat exchanger exchanges heat between the exhaust gas from the turbine wheel and the compressed air from the compressor wheel. And solid oxide fuel cell, the axis of the rotating part consisting of compressor wheel and turbine wheel As well as arranged in the power generation device is proposed which is characterized in that a solid oxide fuel cell so as to surround the radially outer of the combustor.

According to the above structure, the heat exchanger, the combustor, and the solid oxide fuel cell are arranged on the axis of the rotating portion composed of the compressor wheel and the turbine wheel, and the solid electrolyte is surrounded so as to surround the combustor in the radial direction. Since the type fuel cell is arranged, it is possible to suppress the heat generated by the combustor from being recovered by the solid oxide fuel cell and escape to the outside, and to improve the power generation efficiency. Particularly, by effectively heating the solid oxide fuel cell in the initial stage of startup with the heat generated by the combustor, activation can be promoted early.

According to the invention described in claim 2,
In addition to the configuration of claim 1, it is possible to start the gas turbine engine by operating the combustor, and to stop the operation of the combustor after the solid oxide fuel cell is activated by the waste heat of the gas turbine engine. A featured power generator is proposed.

According to the above structure, the combustor is operated only when the gas turbine engine is started, and when the solid electrolyte fuel cell is activated by the waste heat of the gas turbine engine, the operation of the combustor is stopped. It is possible to minimize the operation of the combustor, which consumes a large amount of fuel as compared with the fuel cell, and improve the power generation efficiency.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

1 and 2 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a power generator, and FIG.
FIG.

1 and 2 show a power generator in which a solid oxide fuel cell FC is integrated with a gas turbine engine GT. The gas turbine engine GT is provided with a substantially cup-shaped front casing 11, and a first compressed air passage 1 formed along the inner surface of the front casing 11.
On the upstream side of 2, an intake passage 13 connected to an air cleaner and a silencer (not shown) is connected. A centrifugal compressor wheel 17 and a centrifugal turbine wheel 18 are adjacent and fixed coaxially to a rotating shaft 16 which is supported by a pair of bearings 14 and 15 penetrating the center of the intake passage 13. A plurality of compressor blades 17a radially formed on the outer periphery of the compressor wheel 17 face the intake passage 13, and a plurality of compressor diffusers 19 are provided in the first compressed air passage 12 located immediately downstream of these compressor blades 17a. ... is provided. A generator GE driven by a turbine wheel 18 is provided at the front end of the rotary shaft 16.

An annular heat transfer type heat exchanger 20 is arranged at the rear end of the front casing 11. Heat exchanger 2
Reference numeral 0 indicates that the compressed air passages and the exhaust gas passages are alternately formed in the circumferential direction by arranging a large number of thin metal plates in the radial direction, and the downstream end of the first compressed air passage 12 is located near the rear end outer circumference. And a compressed air outlet 22 at a position near the front end inner circumference, an exhaust gas inlet 23 at a position near the front end outer circumference, and an exhaust gas outlet 24 connected to the atmosphere at a position near the rear end inner circumference. Prepare The heat exchanger 20 includes relatively low temperature compressed air indicated by a solid arrow,
By flowing the relatively high temperature exhaust gas indicated by the broken line arrow in mutually opposite directions, a large temperature difference between the compressed air and the exhaust gas is maintained over the entire length of the flow path to improve the heat exchange efficiency.

A stepped cylindrical rear casing 25 is connected rearward from the inner peripheral surface of the heat exchanger 20, and a solid electrolyte fuel cell FC formed in an annular shape is formed in the rear half of the rear casing 25. It is stored. Rear casing 25
The second compressed air passage 26 formed along the inner peripheral surface of
The upstream end thereof is connected to the compressed air outlet 22 of the heat exchanger 20, and the downstream end thereof is connected to the outer peripheral portion of the solid oxide fuel cell FC. A single-can combustor 27 is arranged radially inside the solid oxide fuel cell FC, and a fuel injection nozzle 28 is provided at the rear end of the combustor 27. Second compressed air passage 2
On-off valves 29 ... Which open and close an opening bypassing the solid oxide fuel cell FC are provided in the middle portion of 6.

An exhaust gas passage 30 extending from a plurality of turbine blades 18a radially formed on the outer periphery of a turbine wheel 18 provided at the rear end of the rotary shaft 16 is connected to an exhaust gas inlet 23 of a heat exchanger 20, The outer side of the exhaust gas passage 30 in the radial direction is covered with the first compressed air passage 12. A heat shield plate 31 is arranged so as to cover the rear surface of the turbine wheel 18, and a turbine nozzle 32 facing the turbine blades 18 a is arranged on the outer peripheral portion of the heat shield plate 31.
Is provided.

The components of the gas turbine engine GT (that is, the compressor wheel 17, the turbine wheel 18, the heat exchanger) with respect to the axis L of the rotating shaft 16 supporting the rotating portion 33 composed of the compressor wheel 17 and the turbine wheel 18. 20 and the combustor 27) and the solid oxide fuel cell FC have an axisymmetric shape.
The space 3 formed behind the rotating portion 33 in the direction of the axis L.
An annular heat exchanger 20 is arranged on the outer side in the radial direction of 4,
Further, an annular solid electrolyte fuel cell FC is arranged behind the heat exchanger 20 in the direction of the axis L, and a solid electrolyte fuel cell F is provided.
The combustor 27 is arranged radially inward of C.

A known solid oxide fuel cell FC is a stack of a large number of cells formed of annular thin plates in the direction of the axis L with a separator of the same shape sandwiched therebetween, and each cell is a ceramic solid electrolyte. A cathode (air electrode) and an anode (fuel electrode) are laminated on both side surfaces of.
Air and fuel are supplied to the cathode and the anode through passages formed in the separator, and they react at the interface of the solid electrolyte to generate electric energy.

Next, the operation of the embodiment of the present invention having the above structure will be described.

During operation of the power generator, the air sucked from the intake passage 13 and compressed by the compressor wheel 17 is sent to the heat exchanger 20 via the first compressed air passage 12, where the high-temperature exhaust gas (about 800 ° C.). By exchanging heat with C), it is heated to near the temperature of the exhaust gas. The high-temperature compressed air that has passed through the heat exchanger 20 reaches the solid oxide fuel cell FC through the second compressed air passage 26 and passes through the solid oxide fuel cell FC from the radially outer side to the radially inner side. On the other hand, the fuel such as natural gas supplied to the solid oxide fuel cell FC (see the white arrow) is internally reformed into H ₂ and CO in the high temperature solid oxide fuel cell FC and supplied from the heat exchanger 20. Electric power is generated by reacting with the generated air.

Since the solid oxide fuel cell FC is not activated when the power generator is started, the combustor 27 is temporarily operated to raise the temperature of the solid oxide fuel cell FC to the activation temperature. That is, when the compressed air from the compressor wheel 17 is supplied from the heat exchanger 20 to the combustor 27 via the solid oxide fuel cell FC, and the compressed air is mixed with the fuel injected from the fuel injection nozzle 28 and burned, The high-temperature exhaust gas is supplied to the heat exchanger 20 to perform heat exchange, and the temperature of the compressed air supplied to the solid oxide fuel cell FC rises. Further, since the turbine wheel 18 is driven by the exhaust gas generated in the combustor 27, intake and compression of air by the compressor wheel 17 are effectively performed, and the temperature of the compressed air supplied to the solid oxide fuel cell FC further rises. To do.

As a result, the temperature of the compressed air supplied to the solid oxide fuel cell FC is a predetermined temperature (for example, 500 ° C.).
C-600 ° C), even if the fuel injection from the fuel injection nozzle 28 is stopped and the combustor 27 is deactivated,
When the temperature of the solid oxide fuel cell FC reaches the activation temperature, the operation of the power generator is continued. On-off valve 29 ...
By controlling the ratio of the amount of compressed air passing through the solid oxide fuel cell FC to the amount of compressed air bypassed by changing the opening degree of the solid electrolyte fuel cell FC, the temperature of the solid oxide fuel cell FC can be controlled, or the solid oxide fuel cell FC can be controlled. It is possible to reduce the pressure loss in the fuel cell FC.

It should be noted that the combustor 27 is movably provided in the direction of the axis L, the combustor 27 is projected inside the rear casing 25 at the time of starting, and the combustor 27 is made to start after starting at the rear casing 25.
If it is evacuated to the outside, the exhaust gas from the solid oxide fuel cell FC will flow smoothly without interfering with the combustor 27 during the operation of the power generator after the start, and further improvement in power generation efficiency is expected. can do.

Thus, the electric power generated by the generator GE driven by the rotating shaft 16 of the turbine wheel 18 and the electric power generated by the solid oxide fuel cell FC are integrated and output. About 50% of the chemical energy of the fuel is converted into electric energy by the solid oxide fuel cell FC, and about 15% is converted into electric energy by the generator GE, so the efficiency of the power generation device reaches 65%. It will be extremely expensive.

Now, with respect to the axis L of the rotating portion 33 composed of the compressor wheel 17 and the turbine wheel 18, the compressor wheel 17 and the turbine wheel 1
8. Since the heat exchanger 20, the combustor 27, and the solid oxide fuel cell FC are arranged axially symmetrically, the flow of compressed air and exhaust gas inside the gas turbine engine GT and the solid oxide fuel cell FC is axially symmetrical. Therefore, the flow velocity of compressed air and exhaust gas flowing into the heat exchanger 20 can be made uniform, and the flow velocity of compressed air flowing into the solid oxide fuel cell FC can be made uniform. Therefore, the heat exchange efficiency in the heat exchanger 20 and the power generation efficiency in the solid oxide fuel cell FC can be improved. In addition, the axisymmetric arrangement of the power generation device reduces pressure loss, which makes it possible to improve power generation efficiency and reduce fuel consumption. Furthermore, the temperature distribution inside the gas turbine engine GT and the solid oxide fuel cell FC is also axially symmetrical, and thermal strain of each member is minimized.
Smooth rotation of the compressor wheel 17 and the turbine wheel 18 is ensured, and damage to the ceramic parts due to thermal stress is prevented, thus improving durability.
Furthermore, since parts such as casings and passages can be made axially symmetrical, it is possible to manufacture them with a thin material such as sheet metal, which not only achieves weight reduction, but also reduces cold mass due to reduction of heat mass. It is possible to further reduce fuel consumption by reducing heat loss at startup.

Further, since the heat exchanger 20 and the solid oxide fuel cell FC, which are formed in an annular shape, are arranged in the outermost layer portion of the power generation device, the space 34 on the radially inner side of the combustor 27 of the gas turbine engine GT or the like is formed. The components can be housed to be compact, and the heat generated by the gas turbine engine GT can be recovered by the outer heat exchanger 20 and the solid oxide fuel cell FC. In particular, since the combustor 27 is arranged in the space 34 on the inner side in the radial direction of the solid oxide fuel cell FC, not only can the size of the power generating device in the direction of the axis line L be made compact, but also in the solid oxide fuel cell FC. The heat can be recovered. In particular,
When the combustor 27 is operated to start the power generator,
It is possible to effectively heat the solid oxide fuel cell FC located on the outer side in the radial direction to enable early activation and to contribute to the reduction of fuel consumption.

Further, since the rotating portion 33 composed of the compressor wheel 17 and the turbine wheel 18, the heat exchanger 20, and the solid oxide fuel cell FC are sequentially arranged from the front to the rear along the axis L, the power generator is arranged. It is possible not only to make the radial dimension of the system compact, but also to make the flow velocity of compressed air and exhaust gas uniform, smooth the flow, reduce pressure loss, and improve power generation efficiency.

Further, the first compressed air passage 12 for introducing the relatively low temperature compressed air from the compressor wheel 17 to the heat exchanger 20, and the exhaust gas passage 30 for introducing the relatively high temperature exhaust gas from the turbine wheel 18 to the heat exchanger 20. Since it is arranged so as to cover the outer side in the radial direction of, the heat escaping from the high temperature exhaust gas passage 30 is recovered by the low temperature first compressed air passage 12 to prevent heat escaping from the front casing 11 and improve power generation efficiency. It can be further enhanced. Further, since the second compressed air passage 26 is arranged so as to cover the outside of the solid oxide fuel cell FC in the radial direction, the solid oxide fuel cell F is formed.
The heat generated by C can be recovered in the second compressed air passage 26 so as not to escape from the rear casing 25 to the outside, so that the power generation efficiency can be further enhanced.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. The second embodiment is different from the first embodiment in the shape of the solid oxide fuel cell FC, and other configurations are the same as those in the first embodiment.

In the second embodiment, a plurality (for example, eight) of solid oxide fuel cells FC formed in an annular shape are circumferentially distributed so as to surround the axis L of the rotating portion 33. It is arranged at intervals. Each solid oxide fuel cell F
C is housed in an annular space 42 defined by the rear casing 25 and the cylindrical partition wall 41, with its axis L1 parallel to the axis L of the rotating portion 33.

Also in this second embodiment, since eight solid oxide fuel cells FC ... Are arranged in axial symmetry with respect to the axis L of the rotating portion 33, the same operational effect as in the first embodiment described above. Can be achieved. In addition, since the diameter of each solid oxide fuel cell FC is smaller than that of the first embodiment, the cells and the separator are small and manufacturing is easy.

Next, a third embodiment of the present invention will be described with reference to FIGS. Also in the third embodiment, the shape of the solid oxide fuel cell FC is different from that of the first embodiment, and other configurations are the same as those of the first embodiment.

In the third embodiment, a plurality of (for example, 12) solid oxide fuel cells FC ...
2 in the direction of the axis L so as to surround the axis L of the rotating unit 33.
It is arranged in rows and at equal intervals in the circumferential direction. The six solid oxide fuel cells FC in each row have their axis L2.
.. in a radial direction with respect to the axis L of the rotating portion 33, the housing is housed in an annular space 42 defined by the rear casing 25 and the cylindrical partition wall 41.

Also in this third embodiment, the twelve solid oxide fuel cells FC ... Are arranged in axial symmetry with respect to the axis L of the rotating portion 33, so that the same effect as the first embodiment described above can be obtained. Can be achieved. In addition to that, since the diameter of each solid oxide fuel cell FC is smaller than that of the first embodiment, the cells and the separator are small in size and the manufacturing is easy, and the solid in the axis L direction is also solid. By arbitrarily increasing the number of rows of the electrolyte fuel cells FC, the outer diameter of the power generation device can be made compact while ensuring the same power generation capacity.

Although the embodiments of the present invention have been described in detail above, the present invention can be modified in various ways without departing from the scope of the invention.

[0036]

As described above, according to the invention as set forth in claim 1, the heat exchanger, the combustor, and the solid oxide fuel cell are arranged on the axis of the rotating portion composed of the compressor wheel and the turbine wheel. Since the solid oxide fuel cell is arranged so as to surround the outer side of the combustor in the radial direction, the heat generated by the combustor is prevented from being recovered by the solid oxide fuel cell and escaped to the outside to improve power generation efficiency. be able to. Particularly, by effectively heating the solid oxide fuel cell in the initial stage of startup with the heat generated by the combustor, activation can be promoted early.

According to the invention described in claim 2,
The combustor is operated only when the gas turbine engine is started, and when the solid electrolyte fuel cell is activated by the waste heat of the gas turbine engine, the operation of the combustor is stopped. The operation of a large combustor can be minimized to increase power generation efficiency.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a power generator.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a vertical sectional view of a power generator according to a second embodiment.

FIG. 4 is a sectional view taken along line 4-4 of FIG.

FIG. 5 is a vertical cross-sectional view of a power generator according to a third embodiment.

6 is a sectional view taken along line 6-6 of FIG.

[Explanation of symbols]

17 compressor wheel 18 turbine wheels 20 heat exchanger 27 Combustor 33 rotating part 34 space FC solid oxide fuel cell GT gas turbine engine L axis

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01M 8/04 H01M 8/04 X Z 8/12 8/12

Claims (2)

[Claims] 1. A power generation device integrally comprising a gas turbine engine (GT) and a solid oxide fuel cell (FC), the gas turbine engine (GT) comprising a compressor wheel (17) and a turbine wheel (18). , Heat exchanger (2
0) and a combustor (27), the compressor wheel (17) supplies compressed air to the solid oxide fuel cell (FC) and the combustor (27) via the heat exchanger (20), and the turbine wheel (17). 18) is driven by the exhaust gas from the solid oxide fuel cell (FC) and the combustor (27) to drive the compressor wheel (17), and the heat exchanger (20) is the exhaust gas from the turbine wheel (18) and the compressor. A heat exchanger (20), a combustor (27), a solid oxide fuel cell (FC), a compressor wheel (17) and a turbine wheel (for a heat exchanger that exchanges heat with the compressed air from the wheel (17)). 18) is arranged on the axis (L) of the rotating part (33), and the solid oxide fuel cell is arranged so as to surround the combustor (27) in the radial direction. Pond (FC)
A power generation device characterized in that. 2. A gas turbine engine (GT) is started by operating a combustor (27), and the solid electrolyte fuel cell (FC) is activated by the waste heat of the gas turbine engine (GT) and then burned. 2. The power generator according to claim 1, characterized in that the operation of the device (27) is stopped.