JP5535713B2 - Gasification combined power generation system - Google Patents

Description

  The present invention relates to a driving method for a gasifying agent compressor and an air compressor of a combined gasification power generation system.

  The combined gasification power generation system gasifies solid and liquid fuel sources such as coal and residual oil in a gasifier, burns this gasified fuel in a gas turbine combustor, and drives the turbine to generate electricity. The gas turbine exhaust gas is introduced into an exhaust heat recovery boiler, and the steam turbine is driven by the steam generated here to generate electric power (for example, Patent Document 1).

Here, in the case of an air-blown gasifier, a part of the outlet air of the gas turbine air compressor is extracted, and this is boosted by a separate compressor, led to the gasifier, and used as a gasifying agent doing. This will be exemplarily described with reference to FIG.
A gasification combined power generation system 100 illustrated in FIG. 5 includes a gasification device 120, a gas turbine 102, and a generator 126. The gas turbine 102 includes an air compressor 110, a combustor 112, and a turbine 114.
The gasifier 120 is configured to generate gasified fuel and supply the gasified fuel to the combustor 112 via the fuel supply path 134. The air compressor 110 is configured to take in air from the atmosphere and increase the pressure. The combustor 112 is configured to mix the high-pressure air pressurized by the air compressor 110 and the gasified fuel supplied from the gasifier 120 and burn the mixed gas. Turbine 114 is configured to extract power from combustion gases in combustor 112. The generator 126 is configured to be driven by the gas turbine 102 to generate power.
The combined gasification power generation system 100 further includes an extraction air path 136, a gasifying agent compressor 118, and a gasifying agent supply path 138.
The extraction air path 136 is configured to extract a part of the outlet air of the air compressor 110. The gasifying agent compressor 118 is arranged as a separate shaft from the gas turbine 102 and is configured to pressurize the air extracted in the extraction air path 136. The gasification agent supply path 138 is configured to supply the air pressurized by the gasification agent compressor 118 to the gasifier 120 as a gasification agent.
In addition, description and description are abbreviate | omitted here about the structure (bottoming system | strain) of a waste heat recovery boiler and a steam turbine.

In the combined power generation system shown in FIG. 5, the gasified fuel supplied from the gasifier 120 is supplied to the combustor 112. Next, the turbine 114 is rotationally driven by the energy of the high-temperature and high-pressure combustion gas generated by mixing the air compressed by the air compressor 110 and the gasified fuel and combusting them in the combustor 112. Since the air compressor 110 is integrally coupled with the turbine 114, the air compressor 110 is driven by the turbine 114.
A part of the air compressed by the air compressor 110 is extracted and pressurized by the gasifying agent compressor 118 via the extraction air path 136 and led to the gasifier 120, where gasified fuel is generated, The gasified fuel is supplied to the combustor 112 of the gas turbine 102 via the fuel supply path 134.
The power obtained by the gas turbine 102 drives the generator 126 to generate power. In this case, since the shaft rotational speed is generally determined by the supplied power frequency, it is operated at a constant rotational speed (synchronous rotational speed) regardless of the operating conditions of the combined power generation system 100. The gasifying agent compressor 118 is driven by a driving machine such as a motor 128.

  The power adjustment of the combined gasification power generation system 100 is performed by adjusting the fuel flow rate. As described above, in the combined gasification power generation system 100, the air extracted from the air compressor 110 is pressurized by the gasifying agent compressor 118, and gasified fuel is generated using this air and supplied to the combustor 112. ing. Therefore, adjusting the flow rate of gasified fuel means adjusting the flow rate of the gasifying agent compressor 118. When the gasifying agent compressor 118 is an axial compressor, the suction flow rate of the gasifying agent compressor 118 is adjusted by a variable stator blade (not shown) provided at the inlet of the gasifying agent compressor 118. At this time, the flow range of the adjustable gasifying agent is limited by the opening range of the variable stationary blade or the surge limit of the gasifying agent compressor 118. For this reason, when the flow range of the required gasifying agent exceeds the adjustment range that is possible with the gasifying agent compressor 118 alone, the gasifying agent is discharged from the gasifying agent compressor 118 as shown in FIG. The suction flow rate of the gasifying agent compressor 118 is ensured by bypassing and recirculating to the inlet of the gasifying agent compressor 118 via the bypass path 130.

  When bypassing the gasifying agent at the time of partial load operation where the required fuel flow rate of the combined gasification power generation system 100 is small, the gasifying agent is boosted in an amount more than that required by the gas turbine 102, and more gasification than necessary is required. Since the power of the agent compressor 118 is consumed, the overall efficiency decreases as a result.

Further, the flow rate adjustment range of the gasifying agent compressor 118 during the partial load operation is limited when the limit pressure ratio of the gasifying agent compressor 118 decreases (the limit pressure ratio is almost proportional to the flow rate) and when the flow rate decreases. The efficiency of the gasifying agent compressor 118 is reduced.
In the axial flow compressor, the operating limit pressure ratio due to surge decreases as the suction flow rate decreases. For this reason, if the suction flow rate of the gasifying agent compressor 118 is reduced while the pressure ratio of the gasifying agent compressor 118 is high, the surge operation limit of the gasifying agent compressor 118 will be exceeded, and the operation should be continued. Can not be.
On the other hand, in order to increase the surge pressure ratio, it is possible to increase the number of stages of the compressor. However, in the rated load operation condition, an originally unnecessary blade row is added. Efficiency is reduced and overall performance is also reduced.

For this reason, it is conceivable that the motor for driving the gasifying agent compressor 118 or the like can be made variable in rotational speed.
According to these configurations, the suction flow rate of the gasifying agent compressor 118 can be adjusted by adjusting the rotational speed. For this reason, it becomes possible to set the flow conditions of the gasifying agent without performing a bypass operation, to reduce the shaft power of the gasifying agent compressor 118, and to improve the partial load efficiency of the gasification combined power generation system to some extent. Can do.

JP 2005-207353 A

  However, since the gas turbine itself drives the generator at a constant rated speed, the air compressor coupled integrally with the generator is also operated at the same constant speed as the gas turbine. For this reason, even in a partial load, the air compressor sucks in a considerable amount of air and generates a high pressure ratio, so that a considerable amount of shaft power is consumed. Furthermore, since the gasifying agent compressor boosts the bleed air of the air compressor, the fact that the pressure ratio of the air compressor is high (the outlet pressure is high) even at a partial load means gasification. This means that the suction pressure of the agent compressor is also high. As a result, even at the partial load, the gasifying agent compressor that further boosts the bleed air of the air compressor consumes extra power. Therefore, the efficiency improvement of the partial load cannot be expected so much simply by changing the rotation speed of the gasifying agent compressor. Furthermore, since the existing configuration requires ancillary facilities for driving the gasifying agent compressor, the manufacturing cost of the gasification combined power generation system is also increasing.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a gasification combined power generation system that is structurally simple, low-cost, and more efficient.

The present invention employs the following means in order to solve the above problems.
The combined gasification power generation system according to the present invention includes a gasification device that generates gasified fuel, a first compressor (for example, an air compressor) that compresses an oxidant (for example, air), and the first compressor. A second compressor (for example, a gasifying agent compressor) that compresses a part of the oxidizing agent compressed in step 1 and supplies the gasifying device as a gasifying agent, and the oxidation compressed by the first compressor A combustor that mixes and burns the agent and the gasified fuel supplied from the gasifier, and generates a high-temperature and high-pressure combustion gas; and a post-connector connected to the combustor, the high-temperature and high-pressure combustion gas A first and a second turbine (for example, a high-pressure turbine and a low-pressure turbine) that are driven in sequence, and a generator that is coupled to the second turbine so as to be capable of transmitting power; And the first turbine are connected to each other so that power can be transmitted. The second compressor is rotationally driven by the first turbine, the second turbine is disposed on the downstream side of the first turbine, and the first and second turbines are as shaft systems. They are not coupled and can be rotated at different rotational speeds.

  According to the combined gasification power generation system according to the present invention, the first and second compressors are driven by the first turbine that can rotate at a rotational speed independent of the second turbine, so that the motor and the like Without having the incidental equipment, the variable flow ranges of the first and second compressors can be expanded, and the production cost can be reduced and the efficiency of the entire system can be improved.

In the combined gasification power generation system, the second compressor may be coupled to the first compressor via a speed increaser or a speed reducer.

In such a combined gasification power generation system, it is possible to design the second compressor at a rated rotational speed different from that of the first compressor, and the first and second compressors each have optimum aerodynamic performance. The efficiency of the entire system is improved.

In addition, the combined gasification power generation system according to the present invention includes a gasification device that generates gasified fuel, a first compressor (eg, air compressor) that compresses an oxidant (eg, air), and the first A second compressor (for example, a gasifying agent) that compresses at least a part of the oxidizing agent compressed by the compressor or an oxidizing agent supplied from the outside (another process) and supplies the compressed oxidizing agent to the gasifier A compressor), a combustor that mixes and burns the oxidant compressed by the first compressor and the gasified fuel supplied from the gasifier, and generates high-temperature and high-pressure combustion gas; First and second turbines (for example, a high-pressure turbine and a low-pressure turbine) that are connected downstream from the combustor and sequentially driven by the high-temperature and high-pressure combustion gas, and are coupled to the second turbine so that power can be transmitted. A first generator and a second generator. The compressor and the first turbine are connected so as to be capable of transmitting power, and the first and second compressors are driven to rotate by the first turbine, and the second turbine is disposed downstream of the first turbine. A turbine is disposed, the first and second turbines are not coupled as a shaft system, can rotate at different rotational speeds, and the oxidant compressed by the second compressor is It is characterized by having a bypass flow path for recirculation on the inlet side of the second compressor .

In such a combined gasification power generation system, the flow rate adjustment of the gasifying agent led to the gasification device can be performed not only by the rotation speed of the second compressor, but also by the bypass flow rate adjustment of the gasifying agent. The controllability of the flow rate of the gasifying agent guided to the gasifier is improved.

A method for operating a combined gasification power generation system according to the present invention includes a gasification device that generates gasified fuel, a first compressor that compresses an oxidant, and an oxidant that is compressed by the first compressor . A second compressor that compresses a part and supplies the gasification device as a gasification agent; an oxidant compressed by the first compressor; and the gasification fuel supplied from the gasification device; Combusting and generating a high-temperature and high-pressure combustion gas; first and second turbines connected downstream from the combustor and sequentially driven by the high-temperature and high-pressure combustion gas; A generator coupled to the second turbine so as to be capable of transmitting power, wherein the first and second compressors and the first turbine are coupled so as to be capable of transmitting power, and the first and second compressions are coupled to each other. The machine constitutes a gas generator unit that is rotationally driven by the first turbine, A second turbine is disposed on the downstream side of the first turbine, and the first and second turbines are not coupled as a shaft system and can rotate at different rotational speeds, In the combined gasification combined power generation system in which the second turbine is coupled to the generator so as to be able to transmit power to form a power turbine unit, the partial load operation of the combined gasification combined generation system is based on the rotational speed at the rated operation. The gas generator section is operated at a lower rotational speed, and the flow rates or pressures at the outlets of the first and second compressors are reduced as compared with the rated operation.

  According to the method of operating the gasification combined power generation system according to the present invention, the gas generator combined power generation system can be operated without changing the efficiency of the first and second compressors by changing the gas generator unit to variable speed operation. Since the pressure ratio can be reduced and partial load operation is possible, there is an effect that the efficiency of the entire system can be improved.

  According to the combined gasification power generation system according to the present invention, it is possible to reduce the manufacturing cost and improve the efficiency of the entire system.

1 is a schematic configuration diagram of a combined gasification power generation system according to a first embodiment of the present invention. It is a characteristic line figure of an axial flow compressor. It is a characteristic line figure of an axial flow compressor. It is a block schematic diagram of the gasification combined cycle power generation system concerning a 2nd embodiment of the present invention. It is a block schematic diagram of the gasification combined cycle power generation system concerning a 3rd embodiment of the present invention. It is the structure schematic of the conventional gasification combined cycle power generation system.

[First Embodiment]
Hereinafter, the combined gasification power generation system according to the first embodiment of the present invention will be described with reference to FIG.
1 includes an air compressor 10 (first compressor), a combustor 12, a high-pressure turbine 14 (first turbine), and a low-pressure turbine 16 (second turbine). The generator 26, the gasifying agent compressor 18 (second compressor), and the gasifier 20. The air compressor 10, the high-pressure turbine 14, and the gasifying agent compressor 18 are coupled to the same rotating shaft, and constitute a gas generator unit 40. Further, the low-pressure turbine 16 and the generator 26 are coupled to the same rotating shaft, and constitute a power turbine unit 42. Here, the high pressure turbine 14 and the low pressure turbine 16 are not coupled as a shaft system, and are configured to be rotatable at different rotational speeds. That is, the gas generator unit 40 and the power turbine unit 42 are configured to be rotatable at different rotational speeds.

The air compressor 10 is configured to compress air taken from the atmosphere. The gasifying agent compressor 18 is configured so that a part of the outlet air of the air compressor 10 is extracted, and the air (extracted air) guided through the extraction air passage 36 is pressurized as a gasifying agent (oxidant). It is configured. The gasification apparatus is configured such that gasified fuel is generated by the fuel source and the gasification agent that is pressurized by the gasification agent compressor 18 and guided through the gasification agent supply path 38. The generated gasified fuel is configured to be supplied to the combustor 12 via the gasified fuel supply path 34. The combustor 12 is configured to inject and burn the gasified fuel supplied from the gasifier 20 into the air compressed by the air compressor 10 to generate high-temperature and high-pressure combustion gas. The high-pressure turbine 14 is driven to rotate by being guided by the high-temperature and high-pressure combustion gas generated by the combustor 12, and the air compressor 10 coupled to the same rotation shaft and the gasifying agent compressor 18 are driven to rotate. Is configured to do. The low-pressure turbine 16 is configured to be driven to rotate by being guided by the outlet gas of the high-pressure turbine 14, and to rotate the generator 26 coupled to the same rotation shaft. The generator 26 is rotationally driven by the low-pressure turbine 16 and configured to generate power.
In addition, description and description are abbreviate | omitted here about the structure (bottoming system | strain) of a waste heat recovery boiler and a steam turbine.

Here, coal, residual oil, etc. are mentioned as a fuel source of a gasifier. Further, since air is used for gasification of the fuel source, the first embodiment is classified as an air blowing type gasifier.
Moreover, it turns out that the air compressed with the air compressor 10 acts as an oxidizing agent as both the combustion air in the combustor 12 and the gasifying agent in the gasifier 20.

Next, an operation method of the gasification combined power generation system according to the first embodiment of the present invention will be described.
The gasification combined power generation system 1 is started up using a starter (not shown). The gasifying agent compressor 18 is rotationally driven together with the air compressor 10 by a high-pressure turbine 14, and the air extracted from the outlet air of the air compressor 10 is pressurized by the gasifying agent compressor 18 to be gasified as a gasifying agent. 20 is supplied. In the gasifier 20, gasified fuel is generated by the fuel source and the gasifying agent. The air compressed by the air compressor 10 and the gasified fuel gas are mixed and burned by the combustor 12 to generate high-temperature and high-pressure combustion gas. The high-pressure turbine 14 and the downstream-side low-pressure turbine 16 are rotationally driven by the energy of the generated high-temperature and high-pressure combustion gas. The low-pressure turbine 16 drives the generator 26 to generate power.

Usually, since the generator needs to transmit power at a constant frequency (synchronous frequency, for example, 60 Hz), the power turbine unit 42 has a constant rotational speed (synchronized with the power transmission system) regardless of the operating conditions of the gasification combined power generation system 1. It is operated at a synchronous rotation speed, for example, 3600 min ⁻¹ .
On the other hand, when the power generation demand is low and the gasification combined power generation system 1 is operated at an output (partial load) lower than the rated output, the required gasifying agent flow rate and combustion air flow rate, that is, the gasifying agent compressor 18 and the air The suction flow rate of the compressor 10 is smaller than that at the rated output. Therefore, the partial load is operated by reducing the rotational speed of the gas generator unit 40 from the rated rotational speed. On the other hand, the power turbine unit 42 is maintained at the synchronous rotation speed. Here, the rated rotational speed of the gas generator unit 40 means the rotational speed when the gasification combined power generation system 1 generates a rated output, but this rotational speed is set to be the same as the synchronous rotational speed. It is not necessary and can be selected according to design conditions as appropriate.

Next, when the electric power demand increases and the gasification combined power generation system 1 is operated at the rated output, the required gasifying agent flow rate and the combustion air flow rate increase, so the rotational speed of the gas generator unit 40 is increased. , Reach the rated speed. As a result, the pressure and temperature of the combustion gas flowing into the power turbine section 42 increase and the output of the power turbine section 42 increases, so that the combined gasification power generation system 1 can be operated at the rated output.

Here, FIG. 2a and FIG. 2b show characteristic diagrams of a compressor having a variable speed.
In FIG. 2a, the horizontal axis represents the suction flow rate of the compressor, and the vertical axis represents the heat insulation efficiency of the compressor. On the other hand, in FIG. 2b, the horizontal axis shows the suction flow rate of the compressor, and the vertical axis shows the ratio (pressure ratio) between the suction pressure and the discharge pressure of the compressor.

As can be seen from FIGS. 2a and 2b, when the rated rotational speed is reduced from 100% rotational speed to 85% rotational speed, the suction flow rate can be reduced to about 45% of the rated flow rate. It turns out that it has hardly decreased since time. Therefore, by setting the gas generator unit 40 to variable speed operation, the pressure ratio of the gasification combined power generation system 1 can be reduced without impairing the efficiency of the gasifying agent compressor 18 and the air compressor 10. Load operation is possible.

In the configuration of FIG. 1, in the gas generator unit 40, the air compressor 10 is integrally coupled to the high-pressure turbine 14 without using a mechanical rotation control device, so there is no loss of mechanical power. Since the same structure as a known gas turbine can be followed, the structure is simple, and the reliability of the gasification combined power generation system 1 can be secured.

Further, as shown in FIG. 1, a configuration may be provided in which a bypass path 30 is provided for returning the gas discharged from the gasifying agent compressor 18 to the inlet of the gasifying agent compressor 18. As a result, the flow rate of the gasifying agent can be adjusted not only by the rotation speed of the gasifying agent compressor 18 but also by adjusting the bypass flow rate of the gasifying agent. Controllability is improved.

[Second Embodiment]
Next, a combined gasification combined power generation system according to a second embodiment of the present invention will be described with reference to FIG. However, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
The gasification combined power generation system 3 according to the second embodiment shown in FIG. 3 is different from the gasification combined power generation system 1 according to the first embodiment in that the gasifying agent compressor 18 is connected to the air through the speed increaser 22. This is a point connected to the compressor 10. In addition, the speed-up gear 22 can use a well-known thing, and is not specifically limited.

When the suction flow rate of the gasifying agent compressor 18 is smaller than the suction flow rate of the air compressor 10 on a volumetric flow rate basis, the gasification agent compressor 18 is more compact than the air compressor 10 as the physique of the compressor. Get smaller. Here, in the case where the efficiency of the air compressor 10 is designed to be optimum, if the rotational speed of the gasifying agent compressor 18 is the same as the rotational speed of the air compressor 10, the gasifying agent compressor having a small physique is used. The peripheral speed (the product of the radius of the rotor blade and the rotational angular velocity) of the rotor blade 18 (not shown) is reduced, and the efficiency is lower than expected.

In other words, in order to ensure the peripheral speed of the rotating blades of the gasifying agent compressor 18 having a small radius of the rotating blades, it is necessary to increase the rotational speed of the gasifying agent compressor 18 compared to the air compressor 10. For this reason, in the present embodiment, the gasifying agent compressor 18 is larger than the air compressor 10 via the speed increaser 22 and can be rotationally driven at a rotational speed that achieves optimum efficiency.

On the other hand, there may be a case where the suction flow rate of the gasifying agent compressor 18 is larger than the air compressor 10 on a volume flow rate basis. In this case, as a physique of the compressor, the gasifying agent compressor 18 is larger than the air compressor 10. For this reason, when each compressor is designed and operated at an optimum rotational speed, the gasifying agent compressor 18 is coupled to the air compressor 10 via a speed reducer, and the gasifying agent compressor 18 is connected to the gasifying agent compressor 18. On the other hand, the rotational speed of the air compressor 10 may be increased.

By adopting the above configuration, in any case, the air compressor 10 and the gasifying agent compressor 18 can be designed to obtain optimum efficiency, respectively. Efficiency can be optimized.

[Third Embodiment]
Next, a combined gasification combined power generation system according to a third embodiment of the present invention will be described with reference to FIG. However, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
The gasification combined power generation system 4 of the third embodiment shown in FIG. 4 is different from the gasification combined power generation system 1 of the first embodiment in the supply source of the gasifying agent. That is, instead of using the bleed air of the air compressor 10 as a gasifying agent, the fluid introduced from another process 46 is pressurized by the gasifying agent compressor 24 and used as a gasifying agent (oxidant). It has become.

Here, as the gasification apparatus in the combined gasification power generation system, in addition to the air blowing type apparatus described in the first embodiment, the oxygen concentration of the gasifying agent supplied to the gasification apparatus is about 21 vol%. Further, oxygen blowing type with higher oxygen concentration (oxygen concentration 95 vol%) and improved air blowing type (oxygen concentration 21 to 40 vol%) are also planned. In a combined gasification power generation system including these gasification devices, the extracted air of the compressor of the gas turbine is not used as a gasifying agent, but is exemplified as an air separation device for separating air into oxygen and nitrogen. A fluid adjusted to a predetermined oxygen concentration produced in another process 46 as is used as a gasifying agent.

  Therefore, in the third embodiment shown in FIG. 4, in the gasification combined power generation system including the oxygen-blown or improved air-blown gasifier, the gasifier that uses a fluid previously generated in another process as a gasification agent The gasifying agent compressor 24 that compresses the air to be supplied to the air compressor 10 is coupled to the air compressor 10 so as to be able to transmit power and is driven. Here, as in the first embodiment, the air compressor 10, the high-pressure turbine 14, and the gasifying agent compressor 24 are coupled to the same rotating shaft, and constitute a gas generator unit 40.

  Also in the configuration of FIG. 4, the power adjustment of the gasification combined power generation system 4 is performed by adjusting the flow rate of the gasification fuel. Accordingly, as in the case of the air-blown gasifier, the flow rate of the gasified fuel corresponds to the flow rate of the gasifying agent used for fuel gasification.

When the demand for electric power is small and the gasification combined power generation system 4 is operated at an output (partial load) lower than the rated output, the required gasifying agent flow rate and combustion air flow rate, that is, the gasifying agent compressor 24 and the air compressor Since the suction flow rate of 10 is small, the operation is performed by reducing the rotational speed of the gas generator section 40 from the rated rotational speed. On the other hand, the power turbine unit 42 is maintained at the synchronous rotation speed. Here, the rated rotational speed of the gas generator unit 40 means the rotational speed when the gasification combined power generation system 4 generates the rated output, but this rotational speed is not necessarily set to be the same as the synchronous rotational speed. It is not necessary and can be selected according to design conditions as appropriate.

Next, when the power demand increases and the combined gasification power generation system 4 is operated at the rated output, the required gasifying agent flow rate and combustion air flow rate increase, so the rotation speed of the gas generator unit 40 is increased. , Reach the rated speed. As a result, the pressure and temperature of the combustion gas flowing into the power turbine section 42 increase and the output of the power turbine section 42 increases, so that the combined gasification combined power generation system 4 can be operated at the rated output.

With the above configuration, the gas generator unit 40 can be operated at a variable speed, so that the pressure ratio of the gasification combined power generation system 4 can be obtained without impairing the efficiency of the gasifying agent compressor 24 and the air compressor 10. The partial load operation becomes possible.

Further, a configuration may be provided in which a bypass passage 30 is provided for returning the gas discharged from the gasifying agent compressor 24 to the inlet of the gasifying agent compressor 24. By setting it as such a structure, the controllability of the gasifying agent guide | induced to the gasifier 20 improves.

Further, the gasifying agent compressor 24 may be driven by being coupled to the air compressor 10 via a speed increaser or a speed reducer (not shown). By adopting such a configuration, even when the physiques of the gasifying agent compressor 24 and the air compressor 10 are different, each can be designed at an ideal rotational speed.

  The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the gist of the present invention.

1, 3, 4 Combined gasification power generation system 10 Air compressor (first compressor)
12 Combustor 14 High-pressure turbine (first turbine)
16 Low pressure turbine (second turbine)
18, 24 Gasifier compressor (second compressor)
20 Gasifier 22 Booster 26 Generator 30 Bypass Path 34 Gasified Fuel Supply Path 36 Extraction Air Path 38 Gasification Agent Supply Path 40 Gas Generator Section 42 Power Turbine Section 46 Other Processes

Claims (4)

A gasifier for generating gasified fuel;
A first compressor for compressing the oxidant;
A second compressor that compresses a part of the oxidant compressed by the first compressor and supplies the gasification device as a gasifying agent;
A combustor that mixes and burns the oxidant compressed by the first compressor and the gasified fuel supplied from the gasifier to generate a high-temperature and high-pressure combustion gas;
First and second turbines connected downstream from the combustor and sequentially driven by the high-temperature and high-pressure combustion gas;
A generator coupled to the second turbine to transmit power,
The first and second compressors and the first turbine are coupled so as to be able to transmit power, and the first and second compressors are rotationally driven by the first turbine,
The second turbine is arranged on the downstream side of the first turbine, and the first and second turbines are not coupled as a shaft system and can rotate at different rotational speeds. ,
A gasification combined power generation system characterized by A gasifier for generating gasified fuel;
A first compressor for compressing the oxidant;
A second compressor that compresses at least a part of the oxidant compressed by the first compressor or an oxidant supplied from the outside and supplies the compressed oxidant to the gasifier as a gasifying agent;
A combustor that mixes and burns the oxidant compressed by the first compressor and the gasified fuel supplied from the gasifier to generate a high-temperature and high-pressure combustion gas;
First and second turbines connected downstream from the combustor and sequentially driven by the high-temperature and high-pressure combustion gas;
A generator coupled to the second turbine to transmit power,
The first and second compressors and the first turbine are coupled so as to be able to transmit power, and the first and second compressors are rotationally driven by the first turbine,
The first of said and second turbine disposed downstream of the turbine, the first and second turbine is not bound as a shaft system, Ri rotatable der at different rotational speed, respectively ,
Having a bypass flow path for refluxing the oxidant compressed by the second compressor to the inlet side of the second compressor;
A gasification combined power generation system characterized by The combined gasification power generation system according to claim 1 or 2 ,
The combined gasification power generation system, wherein the first compressor and the second compressor are coupled via a speed increaser or a speed reducer. A method for operating a combined gasification power generation system, comprising:
A gasifier for generating gasified fuel;
A first compressor for compressing the oxidant;
A second compressor that compresses a part of the oxidant compressed by the first compressor and supplies the gasification device as a gasifying agent;
A combustor that mixes and burns the oxidant compressed by the first compressor and the gasified fuel supplied from the gasifier to generate a high-temperature and high-pressure combustion gas;
First and second turbines connected downstream from the combustor and sequentially driven by the high-temperature and high-pressure combustion gas;
A generator coupled to the second turbine to transmit power,
The first and second compressors and the first turbine are coupled so as to be able to transmit power, and the first and second compressors constitute a gas generator unit that is rotationally driven by the first turbine,
A second turbine is arranged on the downstream side of the first turbine, and the first and second turbines are not coupled as a shaft system and can rotate at different rotational speeds, respectively. In the combined gasification combined power generation system in which the power turbine is coupled to the generator so as to be able to transmit power and constitutes a power turbine section,
During partial load operation of the combined gasification power generation system, the gas generator unit is operated at a rotational speed lower than the rotational speed at the rated operation, and the flow rates or pressures at the outlets of the first and second compressors are set higher than those at the rated operation. Reducing,
A method for operating a gasification combined cycle system characterized by the above.

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