JP3789070B2 - Gas turbine system and operation method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas turbine system that generates power and an operation method thereof, and more particularly, to a gas turbine system that chemically reforms fuel using exhaust gas and an operation method thereof.
[0002]
[Prior art]
A gas turbine system is generally used to supply power, and many are used as a power generation system by supplying power to a generator and converting it into electric power. The basic operation principle of a gas turbine system is that a fuel such as methane is burned by a fluid containing oxygen for combustion such as air pressurized by a compressor, and the resulting combustion gas is passed through a stationary blade. The power is obtained by spraying the rotor blades, and rotating the rotor with the rotor blades. In such a gas turbine system, the efficiency can be increased by increasing the temperature of the combustion gas.
[0003]
Generally, the stationary blades and the moving blades are made of a metal material, and the combustion gas temperature cannot be increased beyond the heat resistance temperature of the metal material without cooling these blades by some means. For this reason, a cooling medium is allowed to flow inside the blade and the blade member is cooled by the cooling medium, or the cooling medium is blown out from the inside of the blade to the blade surface. A method is used in which a film is formed to reduce the transfer of heat from the combustion gas to the blade member. However, even if such a cooling means is used, there is a limit to the increase in the combustion gas temperature. Further, in the method of blowing the cooling medium to the blade surface and reducing the transfer of heat to the blade member, the combustion gas temperature is reduced. As the flow rate rises, the flow rate of the cooling medium also increases, and it is difficult to effectively increase the efficiency due to the influence of the temperature drop due to the mixing of the low temperature cooling medium into the high temperature combustion gas.
[0004]
For this reason, attempts have been made to increase efficiency by recovering the thermal energy remaining in the exhaust gas finally discharged from the gas turbine system with the combustion gas after passing through the moving blades and taking out the power. A typical example is that exhaust gas is guided to an exhaust heat recovery boiler to generate high-temperature and high-pressure steam. This is due to the combined cycle that collects and improves the efficiency of the entire system.
[0005]
In recent years, as another means of improving efficiency by recovering exhaust heat from exhaust gas, the fuel supplied to the gas turbine is chemically reformed by the thermal energy contained in the exhaust gas, and the exhaust gas is improved by improving the chemical energy of the fuel. Proposals have been made to recover heat and improve the efficiency of gas turbine systems.
[0006]
Currently, natural gas is one of the widely used fuels for gas turbines, and the main component of natural gas is methane. As a typical reforming method of methane, there is known a method in which steam is added to methane, and it is converted to hydrogen and carbon monoxide by maintaining a high temperature in the presence of a catalyst such as nickel. As such a gas turbine system for reforming fuel by using methane as a main fuel and gas turbine exhaust gas, for example, those disclosed in Japanese Patent Laid-Open No. 2-286835 (Patent No. 2581825) or Japanese Patent Laid-Open No. 7-269371 have been proposed. Yes.
[0007]
In these proposals, for example, as described in JP-A-7-269371, it is generally considered necessary for reforming methane at a pressure of 7-13.8 ata (0.7-1.38 MPa). Means are described for filling the difference between the temperature of 650 ° C. or higher, preferably about 800 ° C., and the temperature of the gas turbine exhaust gas, which is about 550 ° C. Specifically, Japanese Patent Application Laid-Open No. 2-286835 discloses means for increasing the temperature during reforming by providing an auxiliary combustor in front of the reforming means and burning the fuel with the auxiliary combustor. . Further, in JP-A-7-269371, a turbine blade is cooled by passing water vapor through the blade, and the steam heated to a high temperature by cooling is supplied to the reforming means to raise the reforming temperature above the exhaust gas temperature. Has been proposed.
[0008]
[Problems to be solved by the invention]
However, in these proposals, the operation methods such as starting, changing load, and stopping of such a gas turbine system are not considered in detail.
[0009]
In general, when the temperature of the reforming means is increased by auxiliary combustion, it is known that it is difficult to improve the efficiency of the gas turbine system because fuel is supplied to other than the combustor of the gas turbine. For this reason, in order to obtain high efficiency, it is necessary to perform reforming without using auxiliary combustion, but means for raising the temperature of the reforming means without auxiliary combustion when starting the gas turbine is required. .
[0010]
Further, as described above, a catalyst such as nickel is necessary for reforming methane, and the reforming means is filled or coated with such a catalyst, and contact with methane and water vapor is performed at a high temperature to improve the reforming. The quality reaction proceeds. It is known that a catalyst such as nickel becomes nickel oxide or the like in a high-temperature oxidizing atmosphere, and the performance as a catalyst is remarkably lowered, making it difficult to perform effective reforming. In the operation of a gas turbine system, it is sufficiently considered that the catalyst is exposed to a high-temperature oxidizing atmosphere depending on conditions. Therefore, a means for preventing oxidation of the catalyst and preventing deterioration of reforming performance is required.
[0011]
The present invention has been made in consideration of such points, and the energy recovery rate from the exhaust gas of the gas turbine is high and highly reliable even in the operating state such as the start, load change, and stop of the gas turbine system. It is an object of the present invention to provide a gas turbine system and an operation method thereof.
[0012]
[Means for Solving the Problems]
The present invention relates to a compressor that compresses a fluid containing oxygen for combustion, a combustor that combusts fuel using the fluid containing oxygen, a turbine that converts combustion gas generated in the combustor into power, and an exhaust gas of the turbine. A reformer that chemically reforms the raw fuel using at least a part as a heat source, a reformed fuel supply means that supplies the reformed fuel in the reformer to the combustor, and a raw material that supplies the raw fuel to the combustor A gas turbine system comprising fuel supply means.
[0013]
The present invention further includes an evaporator for evaporating water using at least part of the exhaust gas from the turbine as a heat source and supplying steam, and supplying the steam from the evaporator to at least one of the reformer and the combustor. This is a gas turbine system.
[0014]
As a result, exhaust heat recovery in the gas turbine system is performed not only in the reformer but also in evaporation, and the recovered thermal energy is supplied to the combustor of the gas turbine, further improving the efficiency and output of the gas turbine system. can do.
[0015]
The present invention is a gas turbine system further comprising a desulfurizer for adsorptive desulfurization of a sulfur compound contained in a raw fuel sent to a reformer.
[0016]
Thereby, poisoning to the reforming catalyst by the sulfur compound in the raw fuel can be prevented, and deterioration of reforming performance due to poisoning can be prevented.
[0017]
The present invention is a gas turbine system characterized in that means for pressurizing the reformed fuel is provided between the reformer and the combustor.
[0018]
Thereby, the reforming of the raw fuel can be performed at a low pressure, the reforming rate can be increased, and further, the efficiency and output of the gas turbine system can be improved.
[0019]
The present invention provides a gas turbine system operation method in which a raw fuel supply means supplies raw fuel to a combustor at the start of turbine operation or partial load operation, and the raw fuel flow rate is increased and heated. The reformer is reformed by the reformer after the reformer reaches the reformable temperature, and the reformed reformed fuel is supplied to the combustor by the reformed fuel supply means. The operation method of the gas turbine system.
[0020]
As a result, raw fuel can be supplied to the combustor at the start of gas turbine operation or when the load increases from partial load operation, and the temperature of the reformer can be reformed even in a gas turbine system without auxiliary combustion means. Can be as high as possible. Furthermore, when the reformer becomes hot and reforming is possible, the reformed fuel is supplied to the combustor, so that the exhaust heat recovery by the reformer is performed to improve the efficiency and output of the gas turbine system. can do.
[0021]
In the present invention, at the start of operation or partial load operation, before the reforming temperature is reached before the reformer reaches the oxidation temperature, at least one of raw fuel and steam is passed through or sealed in the reformer. The operation method of the gas turbine system is characterized by stopping.
[0022]
According to the present invention, at the time of starting the operation or partial load operation, the reformer is provided with at least one of inert gas and carbon dioxide before reaching the reforming temperature before reaching the oxidation temperature of the reformer. An operation method of a gas turbine system, characterized by passing or sealing.
[0023]
As a result, the catalyst in the reformer is not exposed to high temperatures in an oxidizing atmosphere at the start of gas turbine system operation or when the load increases from partial load operation, preventing oxidation of the reforming catalyst and reducing reforming performance. Can be prevented.
[0024]
The present invention provides a gas turbine system operating method in which a reformer supplies reformed fuel to a combustor when the turbine load is reduced or stopped, and the temperature of the reformed fuel is reduced by reducing the flow rate. And a step of supplying the raw fuel to the combustor by the raw fuel supply means before the reformer reaches the reformable temperature.
[0025]
As a result, until the temperature of the reformer decreases and exhaust heat recovery by reforming cannot be performed, exhaust gas heat recovery can improve the efficiency and output of the gas turbine system, and the reformer can be reformed at a temperature that can be reformed. The operation of the gas turbine can be continued even at a load as low as less than.
[0026]
According to the present invention, when the load is reduced or when the operation is stopped, the reformer stops at the reforming temperature and reaches a temperature equal to or lower than the oxidation temperature of the reformer. The method of operating the gas turbine system according to the above, wherein the flow through one side is sealed.
[0027]
The present invention provides the reformer with at least one of inert gas and carbon dioxide from when the load is reduced or when the operation is stopped until the reformer stops the reforming and reaches a temperature equal to or lower than the oxidation temperature of the reformer. A gas turbine system operating method characterized by passing or sealing any one of them.
[0028]
As a result, when the gas turbine system is stopped, the catalyst in the reformer is not exposed to a high temperature in an oxidizing atmosphere, so that oxidation of the reforming catalyst can be prevented and deterioration of reforming performance can be prevented.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
First embodiment
Embodiments of the present invention will be described below with reference to the drawings.
[0030]
FIG. 1 is a system diagram of a gas turbine system according to a first embodiment of the present invention.
[0031]
As shown in FIG. 1, the gas turbine system includes a compressor 1 that compresses air 6, and a raw fuel or reformed fuel supply means 26 that is supplied by raw fuel supply means 24 by air 7 compressed by the compressor 1. A combustor 2 that combusts supplied reformed fuel, and a turbine 3 that generates power by high-temperature and high-pressure combustion gas 8 generated in the combustor 2 are provided.
[0032]
The power generated in the turbine 3 is used to drive the compressor 1 and also drives the generator 4 to generate electric power. The combustion gas used for power generation is used as the exhaust gas 9 with reduced temperature and pressure as the turbine 3. Discharged from.
[0033]
Here, natural gas or city gas, which is widely used as gas turbine fuel, is assumed as the raw fuel, but in any case, the main component is methane. The reformed fuel combusted in the combustor 2 is obtained by modifying the pre-reform fuel 23, which is a mixture of the raw fuel supplied by the raw fuel supply means 27 and the water vapor 16 generated in the evaporator 12, in the reformer 10. It is a reformed fuel that contains a large amount of hydrogen.
[0034]
In this case, in the reformer 10, the pre-reforming fuel 23 is guided to the reformer 10 a filled or coated with the reforming catalyst, and reformed by heat exchange with the exhaust gas 9 from the turbine 3. The heat of the exhaust gas 11 that has passed through the reformer 10 is further used to generate water vapor 16 by evaporating water 14 in the evaporator 12, and then discharged as exhaust gas 13. The generated steam 16 is used as utility steam through the utility steam supply means 18, and a part thereof is supplied to the reformer 10 by the reforming steam supply means 46 and used as fuel reforming steam.
[0035]
The raw fuel 19 sent to the combustor 2 and the reformer 10 via the raw fuel supply means 24 and 27 is compressed by a motor 29 in order to increase the supply pressure to the combustor 2 and the reformer 10. Pressurized by machine 20. Further, the water 14 is pressurized by the pump 15 in order to increase the pressure of the water vapor 16 generated in the evaporator 12 to the supply pressure to the reformer 10.
[0036]
The raw fuel supply means 24, the raw fuel supply means 27, the reforming steam supply means 46, and the utility steam supply means 18 are provided with a valve 25, a valve 22, a valve 17, and a valve 28, respectively. The flow rate and pressure of the gas or water vapor flowing through 24, 27, 46 and 18 are adjusted.
[0037]
Next, the operation of the present embodiment having such a configuration will be described. At the start of the gas turbine system, the reforming section 10a of the reformer is maintained at a reformer oxidation temperature of approximately 200 ° C. or less, and air, that is, oxygen exists therein. The raw fuel compressor 20 maintains the pressure in the raw fuel supply means 21 at the supply pressure to the combustor 2 and the reformer 10, but both the valve 25 and the valve 22 are shut off, and the combustor 2 and the reformer 10 are modified. The raw fuel is not supplied to the mass device 10. Further, the valve 17 of the reforming steam supply means 46 for supplying the steam supply to the reformer 10 is also shut off. At the time of start-up, the compressor 1 of the gas turbine is driven by the starter motor 5, and the pressure of the combustor 2 is gradually increased by gradually increasing the rotational speed of the compressor 1, so that the combustor 2 and the turbine 3 are driven by air. Purged.
[0038]
When the rotational speed of the compressor 1 is about 20% of the rated rotational speed, the valve 25 is opened, the raw fuel is supplied to the combustor 2, ignited in the combustor 2, and the raw fuel is combusted in the combustor 2. To do. Next, the raw fuel flow rate to the combustor 2 is gradually increased, and the generation of output at the turbine 3 is also gradually increased. At an appropriate timing until the rotational speed of the compressor 1 reaches the rated rotational speed, the output from the starter motor 5 is disconnected, and the compressor 1 is driven only by the output of the turbine 3.
[0039]
The supply of raw fuel to the combustor 2 is further gradually increased by the operation of the valve 25. When the rotation speed of the compressor 1 reaches the rated rotation speed, the fuel flow rate of the turbine 3 is adjusted by the operation of the valve 25. The load is rated for rotation. The load is taken out from the turbine 3 by the generator 4, and the load is gradually increased. In addition, the supply amount of the raw fuel is gradually increased by operating the valve 25 in order to keep the rotation speed of the turbine 3 at the rated rotation speed. This eventually reaches the rated load operating state. In the rated load operation state, the temperature of the exhaust gas 9 is normally about 550 ° C. to 600 ° C.
[0040]
At the time of such startup, the temperature of the exhaust gas 9 gradually increases, and therefore the temperature of the reforming part 10a of the reformer 10 also gradually increases from a temperature below the reformer oxidation temperature of approximately 200 ° C. or less. The reforming portion 10a is filled or coated with a nickel-based catalyst. It is known that such a nickel-based catalyst is oxidized to nickel oxide and loses its catalytic activity when placed at a temperature higher than that in the presence of oxygen. According to the inventors' experience, the oxidation reaction of nickel becomes remarkable at about 200 ° C., so that the oxidation resistance temperature of the reformer 10 is about 200 ° C. or less. Since air, that is, oxygen exists in the reforming unit 10a at the time of start-up, the catalyst is oxidized when the temperature of the reforming unit 10a exceeds the reformer oxidation temperature of approximately 200 ° C. or less in this state. The performance is significantly impaired.
[0041]
In the present embodiment, in order to prevent such oxidation of the catalyst at the time of startup, the valve 17 is closed before the temperature of the reforming unit 10a exceeds the reformer oxidation temperature of approximately 200 ° C. or less in the startup process. The valve 22 is opened and the raw fuel, that is, methane is introduced into the reforming unit 10a. As a result, the air existing inside is exhausted into the combustor 2 through the reformed fuel supply means 26. Further, the raw fuel is allowed to flow through the reforming unit 10a for an appropriate time to exhaust the remaining air, that is, residual oxygen almost completely, and then the valve 22 is closed to seal the raw fuel in the reforming unit 10a. At this time, the pressure in the reforming unit 10a is always higher than the pressure in the combustor 2, and there is no back flow from the combustor 2 to the reforming unit 10a in any state of the starting process, and there is no original flow in the reforming unit 10a. When the fuel, that is, methane is sealed, the reformer oxidation resistance temperature of about 200 ° C. or lower is exceeded, and further, the rated load state is reached. For this reason, the inside of the reforming unit 10a is not in an oxidizing atmosphere but is sealed with methane, and can exceed the reformer oxidation temperature of 200 ° C. or lower and reach a reformable temperature of approximately 400 ° C. or higher. The reforming can be started without oxidation of the catalyst.
[0042]
Such sealing with the raw fuel in the reforming unit 10a may be performed in accordance with the ignition timing of the combustor 2 or at a slightly delayed timing, thereby making the reforming unit 10a wider. It is protected from oxidation within the temperature range.
[0043]
In parallel with this, water is supplied to the evaporator 12 by the pump 15, and the generated steam 16 is supplied as utility steam by the utility steam supply means 18.
[0044]
When the turbine 3 reaches the rated load operation due to the combustion of the raw fuel, the valve 17 is opened to guide the steam at a flow rate necessary for reforming the raw fuel to the reformer 10. Further, the steam is guided to the combustor 2 through the reformed fuel supply means 26, and at the same time, the raw fuel in the reforming unit 10a is replaced with steam.
[0045]
Thereafter, the valve 22 is opened to supply the raw fuel at a predetermined flow rate to the reformer 10, the raw fuel is reformed by heat exchange with the exhaust gas 9 in the reformer 10, and the reformed reformed fuel is converted into the combustor 2. To supply. By this operation, the water vapor / methane ratio described later is always kept higher than the water vapor / methane ratio in the steady reforming, so that no carbon deposition occurs in the reforming section 10a. As the reformed fuel is generated in the reformer 10, the flow rate of the raw fuel supplied to the combustor 2 is gradually decreased by the operation of the valve 25. There is no supply of raw fuel. Thereafter, by operating the valve 22 and the valve 17, the flow rates of the raw fuel and the water vapor are adjusted, and the operation according to the load of the turbine 3 is performed.
[0046]
Here, switching from operation by combustion of raw fuel to operation by combustion of reformed fuel has been described as after rated load operation, but such operation switching can be performed by the reformer 10. If the temperature is reached, it is possible even under load operating conditions below the rating.
[0047]
Here, the reforming reaction of the raw fuel in the reformer 10 will be described. The steam reforming reaction of methane, which is the main component of raw fuel, is represented by the following chemical formula.
[0048]
CH₄+ H₂O → 3H₂+ CO (1)
Here, the methane reforming reaction is an endothermic reaction, and the heat used for this reaction, that is, the exhaust heat of the exhaust gas 9 from the turbine 3 in the above-described embodiment is reduced by this reaction. The chemical energy of the fuel increases, and the exhaust heat is recovered from the heat of the exhaust gas. The recovered heat is combusted in the combustor 2 of the gas turbine system as a hydrogen-rich reformed fuel having a higher chemical energy than the raw fuel methane, thereby improving the efficiency and output of the gas turbine system. The
[0049]
In such a methane steam reforming reaction, in order to prevent carbon deposition on the reforming catalyst, an excessive amount of steam is supplied relative to methane than represented by the formula (1). FIG. 2 shows the relationship between the steam / methane ratio, reforming temperature, and carbon deposition, as calculated by the inventors.
[0050]
The graph shown in FIG. 2 is derived from the reforming reaction equilibrium conditions when the pressure is 15 atm, and the steam / methane ratio and reforming temperature conditions are in the region below the curve of the graph. There is a possibility of carbon deposition. As shown in FIG. 2, it can be seen that when the reforming temperature is lower than about 400 ° C., the amount of water vapor necessary for preventing carbon deposition increases rapidly. For this reason, the reformable temperature in the reformer 10 can be said to be approximately 400 ° C. or higher.
[0051]
In this embodiment, in order to prevent oxidation of the catalyst at the time of starting, raw fuel, that is, methane is sealed in the reforming unit 10a, and in this state, the reformer oxidation temperature of about 200 ° C. or less is exceeded. Although the rated load was reached, the valve 17 was opened while the valve 22 was closed, water vapor was passed through the reforming unit 10a, the valve 17 was closed, and the reforming unit 10a was sealed with water vapor. You may do it. At this time, the inside of the reforming unit 10a is not an oxidizing atmosphere, but exceeds the reformer oxidation temperature of approximately 200 ° C. or lower in a state where water vapor is sealed, and reaches a reformable temperature of approximately 400 ° C. or higher. For this reason, reforming can be started in the reforming section 10a without oxidation of the catalyst.
[0052]
Further, the valve 22 and the valve 17 are opened, and methane and water vapor are allowed to flow into the reforming unit 10a, and then the valve 22 and the valve 17 are closed, whereby the reforming unit is formed by methane and steam having a high steam / methane ratio. The inside of 10a may be sealed. At this time, the reformer 10a has a reformer oxidation temperature of approximately 200 ° C. or lower and reaches a reformable temperature of approximately 400 ° C. or higher with methane and water vapor that are not in an oxidizing atmosphere sealed. For this reason, reforming can be started without oxidation of the catalyst.
[0053]
In the present embodiment, methane or water vapor is sealed in the reforming unit 10a in order to prevent oxidation of the catalyst at start-up, but the inside of the combustor 2 while performing partial load operation of the turbine 3 is used. In the case of switching from the state in which the raw fuel is burned to the state in which the load is increased and the reformed fuel is burned in the combustor 2, oxidation of the catalyst can be prevented by exactly the same procedure.
[0054]
In the present embodiment, when the load is reduced from the state where the reformed fuel is burned, the temperature of the exhaust gas 9 gradually decreases from about 550 ° C. to 600 ° C. For this reason, the temperature of the reformer 10 also gradually decreases. At this time, before the temperature of the reformer 10 decreases to a reformable temperature of approximately 400 ° C. or higher, the valve 25 is opened and the raw fuel is supplied to the combustor 2 to be combusted. Even if the reforming in the reformer 10 is stopped when the temperature falls below the reformable temperature of about 400 ° C. or higher, the turbine operation can be continued.
[0055]
In this case, the valve 17 is closed before stopping the reforming in the reformer 10, only the raw fuel is supplied into the reforming unit 10a, and then the valve 22 is closed to close the raw material into the reforming unit 10a. Seal the fuel. As a result, the reforming unit 10a is sealed with raw fuel that is not an oxidizing atmosphere, and can pass from the reformable temperature to a temperature lower than the reformer oxidation temperature, thus preventing oxidation of the catalyst. it can. Further, before the reforming in the reformer 10 is stopped, the valve 22 is closed, only the steam is supplied into the reforming unit 10a, and then the valve 17 is closed to seal the steam in the reforming unit 10a. This also prevents the oxidation of the catalyst.
[0056]
Further, by operating the valve 22 and the valve 17, raw fuel and steam having a sufficiently high steam / methane ratio are supplied into the reforming unit 10 a, and then the valve 17 and the valve 22 are closed to provide sufficiently high steam in the reforming unit 10 a. Oxidation of the catalyst can also be prevented by sealing the raw fuel and water vapor with a methane ratio.
[0057]
Further, in the present embodiment, when the operation is stopped from the state in which the reformed fuel is combusted in the combustor 2 with the valve 17 and the valve 22 opened, the valve 17 is closed and the raw fuel is introduced into the reforming unit 10a. The raw fuel is sealed in the reforming portion 10a by supplying only the fuel and then closing the valve 22. By closing the valve 22, the fuel supply to the combustor 2 is cut off, the output of the turbine 3 is reduced, and the rotational speed of the compressor 1 is also reduced, so that the pressure of the combustor 2 is also reduced. When the compressor 1 finally stops rotating, the combustor 2 is filled with atmospheric air. In the process of depressurization to the atmospheric pressure of the combustor 2, the raw fuel sealed in the reforming unit 10a is gradually discharged into the combustor 2, but the reforming is performed even when the gas turbine is stopped. The raw fuel at atmospheric pressure remains in the portion 10a and the reformed fuel supply means 26. For this reason, the reforming part 10a is not in an oxidizing atmosphere but in a state in which the raw fuel is sealed, and can pass up to a temperature equal to or lower than the reformer oxidation temperature, so that oxidation of the catalyst can be prevented. Similarly, the valve 22 is closed immediately before the reforming in the reformer 10 is stopped, and only the steam is supplied into the reforming unit 10a. Thereafter, the valve 17 is closed and the steam is sealed in the reforming unit 10a. This also prevents the oxidation of the catalyst. Further, by operating the valve 22 and the valve 17, raw fuel and steam having a sufficiently high water vapor / methane ratio are supplied into the reforming unit 10a, and then the valve 17 and the valve 22 are closed to provide sufficiently high steam / methane in the reforming unit 10a. Oxidation of the catalyst can also be prevented by sealing the methane ratio raw fuel and water vapor.
[0058]
In the present embodiment, the reforming rate of the raw fuel can be adjusted by adjusting the amount of water vapor supplied to the reformer 10. For example, if the supply amount of water vapor is set to 0, the raw fuel is not reformed, but is simply supplied to the combustor 2 after the heat exchange with the exhaust gas 9 in the reformer 10. In this case, the exhaust heat recovery rate from the exhaust gas 9 is reduced, and the amount of steam supplied to the utility is increased, instead of the power generated by the gas turbine system, that is, the amount of power generation. Thus, in the present embodiment, a so-called thermoelectric variable system that adjusts the generation ratio of power (electric power) and water vapor (heat) according to the form of use can be realized.
[0059]
In the present embodiment, it has been described that air 6 is used for combustion in the combustor 2, but a fluid containing oxygen having a composition other than air, for example, a fluid composed of oxygen and carbon dioxide, or oxygen and argon The effects of the present invention can be obtained in the same manner by using a fluid having many other compositions such as a fluid made of or a fluid made of oxygen and helium.
[0060]
Thus, according to the present embodiment, the reformer can be reformed by increasing the temperature of the reformer at the time of starting the turbine without performing auxiliary combustion as in the prior art. Furthermore, the operation can be performed without causing deterioration in the reforming performance due to oxidation of the reforming catalyst in any state of starting, increasing the load, decreasing the load, and stopping the operation. In addition, exhaust gas recovery by reforming raw fuel significantly improves the efficiency and output of the gas turbine system, and a gas turbine system with variable thermoelectric power can be realized.
[0061]
Second embodiment
FIG. 3 shows a system diagram of a gas turbine system according to the second embodiment of the present invention. In the second embodiment shown in FIG. 3, at least one of inert gas such as nitrogen, argon, or carbon dioxide is supplied to the reforming unit 10a by the supply means 30, and the supply means 30 has a valve. 31 is provided, and the others are substantially the same as those of the first embodiment shown in FIGS.
[0062]
In FIG. 3, gas sealing of the reforming unit 10 a for preventing oxidation of the catalyst is performed by at least one of nitrogen, inert gas, and carbon dioxide from the supply unit 30. A valve 31 is used to prevent backflow from the combustor 2. In general, inert gases such as nitrogen and argon, and carbon dioxide are superior to methane and water vapor as an environment for preventing oxidation. For this reason, in the present embodiment, it is possible to more reliably prevent the reforming catalyst from being oxidized in each operation state of the start of the gas turbine, the increase in load, the decrease in load, and the operation stop, thereby further improving the reliability of the gas turbine system. Can be increased.
[0063]
Third embodiment
FIG. 4 shows a system diagram of a gas turbine system according to the third embodiment of the present invention. In the third embodiment shown in FIG. 4, the valve 32 is provided in the reformed fuel supply means 26 between the reformer 10 a and the combustor 2. Others are substantially the same as those of the second embodiment shown in FIG.
[0064]
In the present embodiment, the procedures for starting the turbine 3, increasing the load, reducing the load, and stopping the operation are substantially the same as those in the first and second embodiments. When the mass portion 10a is sealed with a gas other than an oxidizing atmosphere, the valve 32 is shut off. Thus, for example, even when the pressure in the combustor 2 increases due to combustion vibration or sudden combustion in the combustor 2, the inside of the reforming unit 10 a can be protected from the oxidizing atmosphere regardless of the state of the combustor 2. . For this reason, it is possible to more reliably prevent the oxidation of the catalyst in the reforming unit 10a in each operation state of the turbine 3, such as start-up, load increase, load decrease, and operation stop, and further improve the reliability of the gas turbine system. Can do.
[0065]
Fourth embodiment
FIG. 5 shows a system diagram of a gas turbine system according to the fourth embodiment of the present invention. In the fourth embodiment shown in FIG. 5, the steam supply means 34 is provided between the utility steam supply means 18 and the combustor 2, the valve 33 is attached to the steam supply means 34, and the upstream side of the compressor 20. A desulfurizer 35 for adsorbing sulfur compounds contained in the raw fuel is provided. Others are substantially the same as those of the first embodiment shown in FIGS.
[0066]
In this embodiment, the procedures for starting the gas turbine, increasing the load, reducing the load, and stopping the operation are substantially the same as those in the first embodiment, but in the present embodiment, the evaporator 12 By supplying the generated steam to the combustor 2 by the steam supply means 34, the output and efficiency of the turbine 3 can be further improved. Further, by removing sulfur compounds contained in the raw fuel by the desulfurizer 35, the poisoning of the catalyst in the reforming unit 10a is prevented, and in each operation state of the turbine start-up, load increase, load decrease, and shutdown, the gas turbine The reliability of the system can be further increased.
[0067]
Fifth embodiment
FIG. 6 shows a system diagram of a gas turbine system according to the fifth embodiment of the present invention. In the fifth embodiment shown in FIG. 6, the raw fuel supply means 27 is connected to the upstream side of the compressor 20, and the raw fuel is pressurized by an ejector 36 using steam from the evaporator 12. Is substantially the same as that of the first embodiment shown in FIGS.
[0068]
In the present embodiment, the procedures for starting the turbine, increasing the load, decreasing the load, and stopping the operation are substantially the same as those in the first embodiment. When the reformed fuel is burned, the driving power of the compressor 20 is not required to pressurize the raw fuel with the ejector 36 and supply it to the reformer 10. For this reason, the output and efficiency as a gas turbine system are further improved.
[0069]
Sixth embodiment
FIG. 7 shows a system diagram of a gas turbine system according to the sixth embodiment of the present invention. In the sixth embodiment shown in FIG. 7, the raw fuel supply means 26 is connected to the upstream side of the compressor 20, and the reformed fuel supply means 26 is provided with a compressor 40 driven by the motor 4. Others are substantially the same as those of the first embodiment shown in FIGS.
[0070]
In the present embodiment, the procedures for starting the gas turbine, increasing the load, decreasing the load, and stopping the operation are substantially the same as those in the first embodiment. Since the compressor 40 for pressurizing the reformed fuel is provided between the reformer 10 and the combustor 2, the reforming of the raw fuel in the reformer 10 is performed at a pressure much lower than the pressure in the combustor 2. Can be done.
[0071]
In general, the reforming reaction of methane, which is a raw fuel, is affected by the pressure during reforming. FIG. 8 shows the relationship between the reforming rate of methane and the pressure calculated by the inventors. Here, the reforming rate indicates the proportion of methane that has been converted to hydrogen and carbon monoxide in the methane supplied as the raw fuel. The higher the reforming rate, the higher the reforming rate from hydrogen and carbon monoxide. More conversion to
[0072]
As shown in FIG. 8, it is understood that the lower the pressure, the higher the reforming rate, and the conversion from raw fuel methane to hydrogen and carbon monoxide proceeds. As the reforming rate is high and the conversion from methane to hydrogen and carbon monoxide increases, the amount of exhaust heat recovered from the exhaust gas 9 also increases, and the efficiency and output of the gas turbine system are improved.
[0073]
As described above, in the present embodiment, the operation can be performed without causing the deterioration of the reforming performance due to the oxidation of the reforming catalyst in any state at the time of start-up, load increase, load decrease, and operation stop. it can. Therefore, by reforming the raw fuel at a pressure lower than the pressure in the combustor, exhaust heat recovery can be further enhanced, and the efficiency and output of the gas turbine system can be improved.
[0074]
Seventh embodiment
FIG. 9 shows a system diagram of a gas turbine system according to the seventh embodiment of the present invention. In the seventh embodiment shown in FIG. 9, a steam supply means 43 is provided between the utility steam supply means 18 and the combustor 2, a valve 42 is provided in the steam supply means 43, and a raw fuel supply means 27 is provided. A desulfurizer 44 for adsorbing and desulfurizing sulfur compounds contained in the raw fuel is provided. Others are substantially the same as the sixth embodiment shown in FIG.
[0075]
In the present embodiment, the procedures for starting the turbine, increasing the load, decreasing the load, and stopping the operation are substantially the same as those in the first embodiment, and the reforming is performed at a pressure lower than the pressure of the combustor 2. This is the same as in the sixth embodiment. In the present embodiment, the output and efficiency of the turbine 3 can be further improved by supplying the steam generated in the evaporator 12 to the combustor 2. Further, by removing sulfur compounds contained in the raw fuel by the desulfurizer 44, the reforming catalyst is prevented from being poisoned, and the reliability of the gas turbine system in each operation state of starting, increasing load, decreasing load, and stopping operation of the gas turbine is prevented. The sex can be increased.
[0076]
Eighth embodiment
FIG. 10 shows a system diagram of a gas turbine system according to the eighth embodiment of the present invention. In the eighth embodiment shown in FIG. 10, the raw fuel supply means 27 is connected to the upstream side of the compressor 10, the steam supply means 43 having a valve 42 is connected to the utility steam supply means 18, and the reformed fuel is supplied. The ejector 45 is provided in the means 26, and the steam supply means 43 is connected to the ejector 45. Others are substantially the same as those of the first embodiment shown in FIGS.
[0077]
In this embodiment, the procedures for starting, increasing the load, reducing the load, and stopping the operation of the gas turbine are substantially the same as those in the first embodiment, and the reforming is performed at a pressure lower than the pressure of the combustor 2. This is the same as in the sixth embodiment. When the reformed fuel is burned, the ejector 45 is used to pressurize the reformed fuel and supply it to the combustor 2, so that power for driving the compressor is not required. For this reason, the output and efficiency as a gas turbine system are further improved.
[0078]
【The invention's effect】
As described above, according to the present invention, the reformer can be reformed by increasing the temperature of the reformer when starting the gas turbine without performing auxiliary combustion as in the prior art. In addition, the system can be operated without degradation of reforming performance due to oxidation of the reforming catalyst in any state of startup, load increase, load decrease, or shutdown, and exhaust heat recovery by raw fuel reforming As a result, the efficiency and output of the gas turbine system can be improved. Moreover, the thermoelectric gas turbine system which can adjust the ratio of the output of electric power and heat by adjusting the reforming rate can be realized.
[Brief description of the drawings]
FIG. 1 is a system diagram of a gas turbine system according to a first embodiment of the present invention.
FIG. 2 is a diagram showing carbon deposition characteristics in methane reforming.
FIG. 3 is a system diagram of a gas turbine system according to a second embodiment of the present invention.
FIG. 4 is a system diagram of a gas turbine system according to a third embodiment of the present invention.
FIG. 5 is a system diagram of a gas turbine system according to a fourth embodiment of the present invention.
FIG. 6 is a system diagram of a gas turbine system according to a fifth embodiment of the present invention.
FIG. 7 is a system diagram of a gas turbine system according to a sixth embodiment of the present invention.
FIG. 8 is a diagram showing the pressure dependence characteristics of the methane reforming rate.
FIG. 9 is a system diagram of a gas turbine system according to a seventh embodiment of the present invention.
FIG. 10 is a system diagram of a gas turbine system according to an eighth embodiment of the present invention.
[Explanation of symbols]
1 Compressor
2 Combustor
3 Turbine
4 Generator
10 Reformer
10a reforming section
12 Evaporator
15 Pump
17 Valve
18 Utility steam supply means
20 Compressor
21 Raw fuel supply means
22 Valve
24 Raw fuel supply means
25 Valve
26 Reformed fuel supply means
27 Raw fuel supply means
28 Valve
31 Valve
32 valves
33 Valve
34 Water vapor supply means
35 Desulfurizer
36 Ejecta
40 Compressor
41 motor
42 Valve
43 Water vapor supply means
44 Desulfurizer
45 Ejecta
46 Steam supply means for reforming

Claims (8)

A compressor that compresses a fluid containing oxygen for combustion, a combustor that burns fuel with the fluid containing oxygen, a turbine that converts combustion gas generated in the combustor into power, and at least a part of the exhaust gas of the turbine A reformer that chemically reforms the raw fuel as a heat source, a reformed fuel supply means that supplies the reformed fuel in the reformer to the combustor, and a raw fuel supply means that supplies the raw fuel to the combustor In a method for operating a gas turbine system comprising:
A step of supplying raw fuel to the combustor by raw fuel supply means at the start of gas turbine operation or during partial load operation until the reformer reaches a reformable temperature ;
After the reformer reaches the reformable temperature by increasing the flow rate of the raw fuel and raising the exhaust gas temperature from the turbine , the reformed fuel reformed by the reformer is supplied by the reformed fuel supply means. A process of supplying to the combustor,
Gas turbine operation at the start or reformer a partial load operation to reach a reformable temperature, between before reaching the oxidation temperature of the reformer until the reforming raw fuel to the reformer Or the operation method of the gas turbine system characterized by passing or sealing at least any one of water vapor | steam. A compressor that compresses a fluid containing oxygen for combustion, a combustor that burns fuel with the fluid containing oxygen, a turbine that converts combustion gas generated in the combustor into power, and at least a part of the exhaust gas of the turbine A reformer that chemically reforms the raw fuel as a heat source, a reformed fuel supply means that supplies the reformed fuel in the reformer to the combustor, and a raw fuel supply means that supplies the raw fuel to the combustor In a method for operating a gas turbine system comprising:
A step of supplying raw fuel to the combustor by raw fuel supply means at the start of gas turbine operation or during partial load operation until the reformer reaches a reformable temperature ;
After the reformer reaches the reformable temperature by increasing the flow rate of the raw fuel and raising the exhaust gas temperature from the turbine , the reformed fuel reformed by the reformer is supplied by the reformed fuel supply means. A process of supplying to the combustor,
Gas turbine operation at the start or reformer a partial load operation to reach a reformable temperature, between before reaching the oxidation temperature of the reformer until the reforming, reformer inert A method for operating a gas turbine system, characterized by passing or sealing at least one of gas and carbon dioxide.   The method for operating a gas turbine system according to claim 1, wherein the reformable temperature of the reformer is 400 ° C. or higher.   The method for operating a gas turbine system according to claim 1, wherein the oxidation resistance temperature of the reformer is approximately 200 ° C. or less. A compressor that compresses a fluid containing oxygen for combustion, a combustor that burns fuel with the fluid containing oxygen, a turbine that converts combustion gas generated in the combustor into power, and at least a part of the exhaust gas of the turbine A reformer that chemically reforms the raw fuel as a heat source, a reformed fuel supply means that supplies the reformed fuel in the reformer to the combustor, and a raw fuel supply means that supplies the raw fuel to the combustor In a method for operating a gas turbine system comprising:
A step of supplying reformed fuel to the combustor at the reformer when the load of the turbine is reduced or the operation is stopped;
Supplying the raw fuel to the combustor by the raw fuel supply means after the reformer has been lowered to a temperature lower than the reformable temperature by reducing the flow rate of the raw fuel and lowering the temperature of the exhaust gas from the turbine ; With
A or when the operation is stopped when the load is lowered, stop the reforming in the reformer up to the oxidation temperature below the temperature of the reformer, at least one of a raw fuel or steam to the reformer A method for operating a gas turbine system, characterized by passing or sealing. A compressor that compresses a fluid containing oxygen for combustion, a combustor that burns fuel with the fluid containing oxygen, a turbine that converts combustion gas generated in the combustor into power, and at least a part of the exhaust gas of the turbine A reformer that chemically reforms the raw fuel as a heat source, a reformed fuel supply means that supplies the reformed fuel in the reformer to the combustor, and a raw fuel supply means that supplies the raw fuel to the combustor In a method for operating a gas turbine system comprising:
A step of supplying reformed fuel to the combustor at the reformer when the load of the turbine is reduced or the operation is stopped;
Supplying the raw fuel to the combustor by the raw fuel supply means after the reformer has been lowered to a temperature lower than the reformable temperature by reducing the flow rate of the raw fuel and lowering the temperature of the exhaust gas from the turbine ; With
At least one of inert gas and carbon dioxide is applied to the reformer when the load is reduced or when the operation is stopped , until the reformer stops the reforming and reaches a temperature equal to or lower than the oxidation temperature of the reformer. A method of operating a gas turbine system, characterized in that one is passed or sealed.   The method for operating a gas turbine system according to claim 5, wherein the reformable temperature of the reformer is 400 ° C. or higher.   The method for operating a gas turbine system according to claim 5, wherein the oxidation resistance temperature of the reformer is approximately 200 ° C. or less.

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