JPH065292A - Co-generating apparatus with gas turbine and fuel cell - Google Patents

Abstract

PURPOSE:To effectively recover the heat of a high temperature waste gas by installing a solid electrolytic fuel cell which can recover the heat of a high temperature waste gas together with a high temperature gas turbine power generating apparatus which discharges the waste gas. CONSTITUTION:A heat-exchanging part 12 is installed in a waste gas duct 6 of a high temperature gas turbine 2. Heat exchange is carried out between the high temperature waste gas of the gas turbine 2 which flows in the waste gas duct 6 and the fuel to be supplied to a solid electrolytic fuel cell 5 in the heat-exchanging part 12, so that the fuel cell is heated to the temperature near the operation temperature and with separately supplied air, the battery reaction is carried out to generate power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generates electric power by a generator driven by an open type gas turbine and heats a reaction gas and a solid electrolyte fuel cell by heat of exhaust gas of the gas turbine to cause a cell reaction. The present invention relates to a gas turbine that generates electricity by generating electricity, and a combined generator for a fuel cell.

[0002]

2. Description of the Related Art In a conventional gas turbine power generator which is a combination of an open type gas turbine and a generator, the temperature of the exhaust gas of the gas turbine is 700 ° C. or lower, so that high temperature corrosion is less likely to occur in the latter stage of the gas turbine. A heat recovery means made of a material that need not be taken into consideration, such as a waste heat boiler, is provided to recover the waste heat of the exhaust gas.

[0003]

In recent years, in a gas turbine power generator, the main part of the gas turbine is made ceramic so that the combustion gas burned in the combustor drives the turbine at an operating temperature of about 1350 ° C. to improve power generation efficiency. High-temperature gas turbines for boosting are known, and research and development are being advanced in various fields.

By the way, the exhaust gas temperature of the above-mentioned high temperature gas turbine is significantly higher than that of the conventional one and reaches 900 ° C. or higher. Therefore, it is difficult to recover the heat of this exhaust gas with a conventional waste heat boiler or the like from the viewpoint of high temperature corrosion. However, since the solid electrolyte fuel cell, which has been developed in recent years, has an operating temperature in the 900 ° C. range, it was noted that the solid electrolyte fuel cell can recover the heat of the high temperature exhaust gas of the high temperature gas turbine.

It is an object of the present invention to provide a gas turbine / fuel cell combined power generator capable of recovering the heat of high-temperature exhaust gas from a high temperature gas turbine by installing a solid electrolyte fuel cell in the gas turbine power generator. Is.

[0006]

In order to solve the above-mentioned problems, according to the present invention, a gas turbine driven by combustion gas burned in a combustor, a generator driven by this turbine, fuel and air are used. And a fuel cell having a solid electrolyte body for generating power by supplying the gas turbine and a heater for heating at least one of the fuel and the air by high-temperature exhaust gas discharged from the gas turbine. It shall constitute a power generator.

In the heater for heating the fuel or air, the fuel and the air respectively flow in the exhaust gas duct through which the high temperature exhaust gas from the gas turbine is introduced, and the heat provided with the heat transfer tube for transferring the heat of the exhaust gas. An exchange unit shall be provided. Further, an exhaust gas discharge pipe is provided for guiding the exhaust gas discharged from the fuel cell having the solid electrolyte body to the exhaust gas duct through which the high temperature exhaust gas from the gas turbine is guided.

In addition, a gas turbine and a fuel cell combined power generation apparatus is a gas turbine driven by combustion gas burned in a combustor, a generator driven by this turbine, and high-temperature exhaust gas discharged from the gas turbine. And a fuel cell having a solid electrolyte body which is disposed in an exhaust gas duct through which the fuel is introduced and which is supplied with fuel and air from the outside to generate electric power.

[0009]

Since the exhaust gas temperature of the high temperature gas turbine constituting the gas turbine power generator is 900 ° C. or higher as described above, the fuel and air supplied to the solid electrolyte fuel cell whose operating temperature is in the 900 ° C. range due to this high temperature exhaust gas. A heater for heating at least one of the above, and the fuel and air respectively flow in the exhaust gas duct through which the exhaust gas of the high temperature gas turbine is guided as the heater, and the heat of the high temperature exhaust gas of the high temperature gas turbine is transferred. By disposing the heat exchange section including the heat transfer tube, at least one of fuel and air is heated by the exhaust gas through the heat transfer tube and supplied to the solid electrolyte fuel cell disposed outside the exhaust gas duct. So
The fuel supplied to the fuel cell is reformed to generate a reaction gas fuel, and the fuel and the supplied air cause a cell reaction to generate electricity.

During power generation by the fuel and air supplied by the solid electrolyte fuel cell arranged outside the exhaust gas duct, the exhaust gas discharged from this fuel cell is guided to the exhaust gas duct through the exhaust gas discharge pipe. Therefore, the high-temperature exhaust gas from the fuel cell flows into the exhaust gas duct together with the exhaust gas from the high-temperature gas turbine. Therefore, when the heat recovery of the exhaust gas is performed in the subsequent stage, the exhaust heat of the exhaust gas from the fuel cell can be effectively recovered.

Further, by disposing the solid electrolyte fuel cell in the exhaust gas duct through which the exhaust gas of the high temperature gas turbine is guided, the reaction gas of the solid electrolyte fuel cell is heated to near the operating temperature by the exhaust gas, and the fuel cell is heated. To react with the exhaust gas and discharge the hot reaction exhaust gas. Therefore, by supplying a fuel, for example, kerosene or light oil, to the solid oxide fuel cell, the fuel is reformed to generate hydrogen or carbon monoxide as a fuel for the reaction gas.

Further, air is supplied to the solid electrolyte fuel cell, and a cell reaction is caused by the reaction gas air heated by the exhaust gas and the reaction gas fuel to generate electricity. Therefore, the high temperature gas turbine drives the generator to generate power, and the solid electrolyte fuel cell that recovers the heat of the exhaust gas of the high temperature gas turbine also generates power.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 shows a gas turbine according to an embodiment of the present invention,
FIG. 3 is a partial cross-sectional configuration diagram of a fuel cell combined generator. Figure 1
In the above, the gas turbine power generator is composed of a high temperature gas turbine 2 having a combustor 1 and a high frequency generator 3 having a rotor connected to the rotor of the high temperature gas turbine 2. The internal main part of the high-temperature gas turbine 2 is made of ceramic so as to withstand high-temperature corrosion.

The solid electrolyte fuel cell 5 has a solid electrolyte composed of stabilized zirconia, and is arranged outside an exhaust gas duct 6 through which exhaust gas discharged from the high temperature gas turbine 2 is guided. Further, a heat exchange section 12 is provided in the exhaust gas duct 6 as a heater for heating fuel such as kerosene or light oil. The heat exchange unit 12 is configured by connecting a straight heat transfer pipe through which the fuel supplied to the solid oxide fuel cell 5 flows to the inlet header and the outlet header, is disposed in the exhaust gas duct 6, and is disposed in the exhaust gas duct 6. Exhaust gas from the high-temperature gas turbine 2 flowing through the heat transfer tube exchanges heat with the heat transfer tube to heat the fuel flowing through the heat transfer tube. The heat transfer tube, the inlet header, and the outlet header are made of a ceramic coating material resistant to high temperature corrosion or a ceramic such as SiC.

The fuel inlet pipe 13 penetrates the exhaust gas duct 6 and is connected to the inlet header of the heat exchanging section 12 to supply the fuel to the heat exchanging section 12. The fuel delivery pipe 14 is connected to the outlet header of the heat exchange section 12 and the solid electrolyte fuel cell 5, and the heat exchange section 12 exchanges heat with the exhaust gas via the heat transfer tube to heat the fuel heated to raise the temperature of the solid electrolyte. Supply to the fuel cell 5. The fuel inlet pipe 13 and the fuel delivery pipe 14 are made of ceramic or titanium alloy as described above.

The air supply pipe 15 is connected to the solid electrolyte fuel cell 5 and supplies room temperature air to the fuel cell. The exhaust gas discharge pipe 16 penetrates the exhaust gas duct 6 and opens in the duct to be connected to the solid electrolyte fuel cell 5, and discharges the exhaust gas generated by the cell reaction in the fuel cell into the exhaust gas duct 6. Here, the exhaust gas discharge pipe 16 is also made of ceramic or titanium alloy. Reference numeral 17 is a lead wire for extracting DC power from the fuel cell.

With such a structure, the high temperature combustion gas generated by burning fuel such as kerosene or light oil in the combustor 1 with the combustion air rotates the rotor of the high temperature gas turbine 2, and accordingly high frequency power generation. By rotating the rotor of the machine 3, the high frequency generator 3 generates high frequency electric power. In addition, the exhaust gas discharged from the high temperature gas turbine 2 is 900
When the temperature reaches ℃ or more, it flows through the exhaust gas duct 6 and is discharged to the outside.

On the other hand, in the solid electrolyte fuel cell 5,
The fuel is supplied to the heat transfer tube of the heat exchange section 12 through the fuel inlet tube 13, exchanges heat with the exhaust gas through the heat transfer tube to be heated to a high temperature, and then is supplied to the solid oxide fuel cell 5 through the fuel delivery tube 14. It The fuel supplied to the solid oxide fuel cell 5 is reformed to generate hydrogen and carbon monoxide as a reaction gas fuel, and this reaction gas fuel reacts with the supplied air in a cell reaction in the fuel cell to generate a direct current. To generate electricity.

The fuel cell is supplied with air for reaction gas as well as for cooling, and heat generated during power generation of the fuel cell is removed by air for cooling to maintain the operating temperature of the fuel cell. To be done. Here, the high-temperature exhaust gas generated by the cell reaction in the solid oxide fuel cell 5 is introduced into the exhaust gas duct 6 through the exhaust gas exhaust pipe 16 and exhausted.

Therefore, the high-temperature exhaust gas from the solid electrolyte fuel cell 5 flows in the exhaust gas duct 6 together with the exhaust gas from the high-temperature gas turbine 2, and the exhaust heat of the exhaust gas is supplied to the waste heat cogeneration system generally provided in the latter stage. Heat is recovered. In the above embodiment, the solid electrolyte fuel cell 5
Only the fuel to be supplied to the
Further, a heat transfer tube through which air flows is provided as a heater for heating the air, and the heat exchange section having the same configuration as that described above is provided in the exhaust gas duct 6, and the air is heated in the heat exchange section by the exhaust gas from the high temperature gas turbine 2. Even if the heated fuel and air are supplied to the solid electrolyte fuel cell 5, the same effect as described above can be obtained.

As described above, the fuel cell maintains the operating temperature by removing the heat generated during power generation by the air for cooling. Further, in FIG. 1, the heat exchanging section 12 for heating the fuel is provided in the exhaust gas duct, but instead, a heat exchanging section having a heat transfer tube as a heater for heating air is provided in the exhaust gas duct 6 for solid electrolyte. Even if the fuel cell 5 is supplied with unheated fuel and heated air, the same effect as described above can be obtained. In this case, the fuel is preferably gas.

As described above, the fuel cell maintains the operating temperature by removing the heat generated during power generation by the air for cooling. FIG. 2 is a partial cross-sectional configuration diagram of a gas turbine and a fuel cell combined generator according to another embodiment of the present invention. In FIG. 2, the solid electrolyte fuel cell 5 has a solid electrolyte made of stabilized zirconia, and is arranged in an exhaust gas duct 6 through which exhaust gas discharged from the high temperature gas turbine 2 is guided. The solid electrolyte fuel cell 5 is housed in a case made of a ceramic coating material or ceramics.

The fuel supply pipe 8 and the air supply pipe 9 penetrate the exhaust gas duct 6 and are connected to the solid electrolyte fuel cell 5, respectively, so that fuel such as kerosene or light oil is supplied through the fuel supply pipe 8 and air is supplied by air. It is supplied to the fuel cell via a tube 9. The exhaust gas discharge pipe 10 opens in the exhaust gas duct 6 and is connected to the solid electrolyte fuel cell 5, and discharges the exhaust gas generated by the cell reaction in the fuel cell into the exhaust gas duct 6.

The fuel supply pipe 8, the air supply pipe 9 and the exhaust gas discharge pipe 10 are all made of ceramic or titanium alloy. Reference numeral 11 is a lead wire that is inserted into a heat-resistant protective tube (not shown) for extracting DC power. The gas turbine power generator is the same as that shown in FIG. With such a configuration, the gas turbine power generator is operated to generate power as described above, and the high temperature exhaust gas of the high temperature gas turbine 2 flows through the exhaust gas duct 6. On the other hand, the solid electrolyte fuel cell 5 arranged in the exhaust gas duct 6 is heated by the high-temperature exhaust gas flowing in the exhaust gas duct 6 to raise its temperature, and the solid electrolyte fuel cell 5 is supplied with fuel through the fuel supply pipe 8 supplied to the solid electrolyte fuel cell 5. For example, kerosene or light oil, and the air passing through the air supply pipe 9 are heated to near the operating temperature, and as described above, the reforming reaction and the battery reaction occur to generate direct current power, and direct current power is taken out from the lead wire 11. To be done.

At this time, the heat generated during power generation of the fuel cell is removed by the air as described above, and the operating temperature of the fuel cell is maintained. The high-temperature exhaust gas generated by the cell reaction in the solid electrolyte fuel cell 5 is discharged from the exhaust gas exhaust pipe 10 into the exhaust gas duct 6, and is discharged to the outside together with the high-temperature exhaust gas of the high-temperature gas turbine 2, so that the exhaust heat of the exhaust gas is discharged. As mentioned above, it is effectively recovered in the latter stage.

Next, FIG. 3 shows a system flow of a power generator in which the above gas turbine power generator and a solid electrolyte fuel cell are provided together. In FIG. 3, a fuel 20 such as natural gas, petroleum, or methanol is a high temperature gas turbine 2 which is made into ceramic.
1 is sent to the combustor and burned, and the combustion gas generated at this time drives the high temperature gas turbine at an operating temperature of about 1350 ° C.

When the high temperature gas turbine 21 is driven, the high speed high frequency generator 22 coupled to the gas turbine is driven to generate high frequency power. The power generation efficiency of this high-temperature gas turbine power generator is as high as 40% or more, and the generator is downsized by using the high-speed high-frequency generator. The high frequency power output from the high speed high frequency generator 22 is converted into power of a commercial frequency by the AC-AC converter 23.

On the other hand, the solid electrolyte fuel cell 24 using stabilized zirconia as the solid electrolyte is supplied with fuel 20 and air (not shown). In this case, as described above, a heater for heating at least one of fuel and air, a heat exchange section is provided in the exhaust gas duct of the high temperature gas turbine 21 as this heater, or the solid electrolyte fuel cell 24 is connected to the high temperature gas turbine 21. The exhaust gas of the high temperature gas turbine 21 heats the fuel cell or at least one of the fuel and air to cause a cell reaction by placing the exhaust gas in the exhaust gas duct of the high temperature gas turbine 21 to bring the fuel cell to an operating temperature of 900 to 1100 ° C. Hold and generate DC power.

The DC power generated by the solid oxide fuel cell 24 is converted into a commercial frequency power by the DC-AC converter 25, is paralleled with the commercial frequency power converted by the AC-AC converter 23, and is supplied to the outside. To be done. FIG. 4 is a functional block diagram of the above-mentioned combined power generation device. In FIG. 4, the high frequency power generator 22 coupled to the high temperature gas turbine 21 generates high frequency power as described above. This high frequency power is converted into commercial frequency power by the AC-AC converter 23.

On the other hand, the solid electrolyte fuel cell 24 is heated by at least one of fuel and air supplied to the solid oxide fuel cell 24 by the exhaust gas of the high temperature gas turbine 21 or the fuel cell to cause a cell reaction to generate direct current power. Generate electricity. Then, this DC power is converted into commercial frequency power by the DC-AC converter 25, is paralleled with the commercial frequency power converted by the AC-AC converter 23, and is supplied to the outside.

[0031]

As is apparent from the above description, according to the present invention, at least one of the fuel and air supplied to the fuel cell is supplied to the high temperature gas in the exhaust gas duct through which the high temperature exhaust gas from the high temperature gas turbine is introduced. A heater that is heated by the exhaust gas from the turbine, by disposing a heat exchange section including a heat transfer tube in which the fuel and the air respectively flow in the exhaust gas duct as this heating, or by disposing a solid electrolyte fuel cell, Since the gas is generated by the gas turbine power generator and the solid electrolyte fuel cell is maintained at the operating temperature to generate power, the heat of the high temperature exhaust gas from the high temperature gas turbine can be effectively recovered.

Further, since the high temperature exhaust gas from the solid electrolyte fuel cell flows in the exhaust gas duct together with the exhaust gas from the high temperature gas turbine, when recovering the waste heat of the exhaust gas flowing through the exhaust gas duct in the subsequent stage, The waste heat of exhaust gas can also be effectively recovered.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional configuration diagram of a gas turbine and a fuel cell combined generator according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional configuration diagram of a gas turbine and a fuel cell combined generator according to another embodiment of the present invention.

FIG. 3 is a system flow diagram of a gas turbine in FIG. 1 and FIG.

FIG. 4 is a functional block diagram of the combined power generation device of the gas turbine and the fuel cell in FIGS. 1 and 2.

[Explanation of symbols]

 2 High temperature gas turbine 3 High frequency generator 5 Solid electrolyte fuel cell 6 Exhaust gas duct 12 Heat exchange section 16 Exhaust gas exhaust pipe

Claims (4)

[Claims] 1. A gas turbine driven by combustion gas combusted in a combustor, a generator driven by this turbine, a fuel cell having a solid electrolyte body for supplying fuel and air to generate power, and a gas. A combined power generator for a gas turbine and a fuel cell, comprising a heater for heating at least one of fuel and air by high-temperature exhaust gas discharged from the turbine. 2. The gas turbine / fuel cell combined power generator according to claim 1, wherein the heater for heating the fuel or air is such that the fuel and air are introduced into an exhaust gas duct through which high-temperature exhaust gas from the gas turbine is introduced. A combined power generation device for a gas turbine and a fuel cell, which is provided with a heat exchange section provided with a heat transfer tube through which each of the flows and heat of exhaust gas is transferred. 3. A gas turbine and fuel cell combined power generator according to claim 1, wherein an exhaust gas discharged from a fuel cell having a solid electrolyte body is introduced into an exhaust gas duct through which high temperature exhaust gas from the gas turbine is introduced. Gas turbine and fuel cell combined power generation device characterized by the provision of 4. A gas turbine driven by combustion gas burned in a combustor, a generator driven by this turbine, and an exhaust gas duct for introducing high-temperature exhaust gas discharged from the gas turbine, A gas turbine and a fuel cell combined power generation device, comprising: a fuel cell having a solid electrolyte body that is supplied with fuel and air from the outside to generate electricity.