JPH10311206A - Combined cycle power generation plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize a heat source, and further improve plant heat efficiency by arranging a lubricating oil plant in bearings to pivot the turbine rotor of a gas turbine plant and a steam turbine plant, and supplying heat generated from this lubricating oil plant to a fuel heating system. SOLUTION: In a combined cycle power generation plant 30 having a gas turbine plant 31, a steam turbine plant and an exhaust heat recovering boiler 33, a lubricating oil plant 34 is composed of a lubricating oil circulating system 57 having an oil tank 51, an oil pump 52, an oil cooler 53 and a lubricating oil adjusting valve 54. Lubricating oil of the oil tank 51 is boosted by the oil pump 52, and is supplied to bearings 56a and 56b, and the lubricating oil is heated by rolling frictional heat of a turbine rotor 55. This heated lubricating oil is guided to a fuel heating system 38 through the lubricating oil circulating system 57, and fuel F is heated, and the fuel F is evaporated, and steam is removed, and its fuel F is supplied to a gas turbine combustor 36. Afterwards, the lubricating oil is returned to the oil tank 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined cycle power plant, and more particularly, to a method for preheating a fuel to be supplied to a gas turbine combustor of a gas turbine plant combined with a steam turbine plant and increasing the calorific value thereof to increase the plant heat efficiency. The present invention relates to a combined cycle power plant with improved power generation.

[0002]

2. Description of the Related Art A recent thermal power plant has a shorter start-up operation time than a conventional power plant.
Combined cycle power plants with high plant thermal efficiency are becoming mainstream. This combined cycle power plant combines a gas turbine plant with a steam turbine plant and an exhaust heat recovery boiler, and uses the exhaust heat (exhaust gas) generated from the gas turbine plant to generate steam using the exhaust heat recovery boiler. Is supplied to a steam turbine plant to generate electric power. As an example, there is a configuration shown in FIG.

[0003] The combined cycle power plant 1 comprises:
The configuration includes a gas turbine plant 2, a steam turbine plant 3, and an exhaust heat recovery boiler 4.

The gas turbine plant 2 includes an air compressor 5, a gas turbine combustor 6, and a gas turbine 7. The air AR sucked by the air compressor 5 is pressurized, and a fuel F is added to the high-pressure air. The combustion gas is generated in the combustor 6, and the gas turbine 7 is driven using the combustion gas as a driving gas.

The exhaust heat recovery boiler 4 includes a superheater 8 and a steam drum 9 arranged from the upstream side to the downstream side along the flow of the exhaust heat (exhaust gas) G from the gas turbine 7.
The evaporator 10 and the economizer 11 are connected to the casing 12, and water supplied from the steam turbine plant 3 is supplied to the economizer 1.
1, and the heated water (water supply after heating) is supplied to the control valve 13
After controlling the flow rate, the steam is guided to the steam drum 9 where it is naturally circulated in the evaporator 10 using the specific gravity of the heated water to become saturated steam, and the saturated steam is heated again by the superheater 8 to remove the superheated steam. The superheated steam is generated and supplied to the steam turbine plant 3 as turbine drive steam.

On the other hand, the steam turbine plant 3 is provided with a steam turbine 15, a condenser 16, a condensate pump 17, a deaerator 18, and a water supply pump 19, which are directly connected to a power generator 14, and the superheat of the exhaust heat recovery boiler 4. The steam driven steam (superheated steam) supplied from the steam generator 8 is expanded by the steam turbine 15,
The generator 14 is driven by the rotational torque generated at the time of the expansion work to generate an electric output.

[0007] The steam turbine plant 3 converts the turbine exhaust gas having completed the expansion work in the steam turbine 15 into a condenser 1.
The condensed water is condensed at 6 and the condensed water is pressurized by a condensate pump 17 to supply water. The dissolved oxygen contained in the supplied water is evacuated or heated and deaerated by a deaerator 18.
To return to the economizer of the exhaust heat recovery boiler 4.

Further, the steam turbine plant 3 includes gland seal portions 15a and 15b at the shaft end of the steam turbine 15, and a part of the superheated steam generated from the superheater 8 of the exhaust heat recovery boiler 4 is transferred to the gland seal portion 15a. The steam is supplied to seal the casing end, and the steam after the sealing is supplied to another gland sealing portion 15b for sealing. After the sealing, the steam is collected by the condenser 16.

On the other hand, bearings 21a and 21b are mounted on a turbine rotor 20 which directly connects the gas turbine plant 2 and the steam turbine plant 3 with shafts.
Is provided with a lubricating oil plant 22.

The lubricating oil plant 22 includes an oil tank 2
3, oil pump 24, oil cooler 25, cooling water cooler 26,
A cooling water pump 27 is provided, and the pressure of the lubricating oil from the oil tank 23 is increased by the oil pump 24 and guided to the bearings 21a and 21b.
Here, the lubricating oil heated by the frictional heat of rotation of the turbine rotor 20 is returned to the oil tank 23 at normal temperature by the oil cooler 25.

Further, the lubricating oil plant 22 supplies the cooling water from the cooling water cooler 26 to the oil cooler 25 via the cooling water pump 27, and cools the lubricating oil heated at the bearings 21a and 21b to room temperature. At that time, the cooling water whose temperature has been raised is returned to the cooling water cooler 26 and used again as cooling water.

In the conventional combined cycle power plant 1 having such a configuration, the Brayton cycle of the gas turbine 2 and the Rankine cycle of the steam turbine plant 3 are skillfully combined to effectively utilize the exhaust heat of the gas turbine plant 2. This made the plant thermal efficiency higher than that of a conventional power plant.

However, as a technique for further improving the plant thermal efficiency of the conventional combined cycle power plant 1, for example, Japanese Patent Application Laid-Open No. 2-283803 has already been published.

According to the technique disclosed in Japanese Patent Application Laid-Open No. Hei 2-283803, as shown in FIG. 10, a gas turbine plant 2 and a fuel heating device 28 are provided. Small waste heat recovery boiler 4
The heating water at the outlet side of the economizer 11 is heated, the fuel F is heated, and the latent heat required when the water vapor contained in the fuel evaporates is removed, thereby increasing the calorific value. To generate combustion gas to improve plant thermal efficiency.

As described above, in the conventional combined cycle power plant 1, today, when there is a concern about depletion of fossil fuels, the amount of fuel F consumed is extremely reduced to improve plant thermal efficiency.

[0016]

In the conventional combined cycle power plant 1 shown in FIG. 10, when the fuel F is heated by the fuel heating device 28, the heating source thereof is heated water supplied from the economizer 11. Saver 1 to ask for
Although the heat transfer area of No. 1 is increased as compared with the related art, the fact that the heating source for the feed water from the economizer 11 is itself involves some problems that need to be improved.

Generally, in this type of technical field, the design differential pressure (generally about 1.5 MPa to 2 MPa) of the control valve 13 provided on the inlet side of the steam drum 9 is equal to the pressure required by the fuel heating device 28 (generally 0 MPa). .2MPa). Therefore, when the heated water exiting the economizer 11 flows into the steam drum 9, the pressure of the heated water is adjusted to the saturation pressure with respect to the temperature of the heated water itself so as not to generate steaming (a type of evaporation). It is necessary to set a high value obtained by adding the design differential pressure and the safety coefficient of No. 13.

However, the heating water supplied to the fuel heating device 28 should have a pressure of about 0.2 MPa plus a safety factor even if the prevention of steaming is considered. Setting itself is useless,
This forces unnecessary power consumption of the feed pump 19.

It is appropriate to set the heating source that requires the fuel heating device 28 to a temperature obtained by adding the temperature of the heated fuel to about 50 ° C. (generally, about 150 ° C. to 200 ° C.). Originally, the temperature of the heating water exiting the economizer 11 is set from the heat balance of the entire plant irrespective of fuel heating. For this reason, the temperature of the heating water on the heat balance increases by the amount of fuel heating, the saturation pressure based on the increased temperature also increases excessively, and a high boosting power of the water supply pump 19 is required, resulting in an increase in cost.

Further, as in the case of the partial load operation, when the amount of heating water supplied to the fuel heating device 28 decreases, the amount of water supplied through the economizer 11 also decreases. Because the internal pressure is high, the economizer 11
The heated water that has flowed out exceeds the saturation temperature, and steaming may occur.

As described above, in the conventional combined cycle power plant 1 shown in FIG. 10, although the heat efficiency of the plant is improved, the above-described problem is caused.
It was necessary to reconsider the selection of the heating source.

On the other hand, in the conventional combined cycle power plant 1 shown in FIG. 9, the sealing steam used in the gland seal portions 15a and 15b of the steam turbine 15 is recovered in the condenser 16 while the temperature is high. Have been. In the lubricating oil plant 22, the bearings 21a, 21
When cooling the high-temperature lubricating oil discharged from b with the oil cooler 25, the cooling source is required to be the cooling water of the cooling water cooler 26, but the cooling source for cooling the cooling water depends on seawater or the like, The seawater and the like heated during the heat exchange are discharged into the ocean.

As described above, in the conventional combined cycle power plant 1, there are many so-called heating sources, and the sealing steam of the gland seal portions 15a and 15b and the lubricating oil of the oil cooler 25 are used as the heating sources. If these heating sources are supplied to the fuel heating device 28 and used to heat the fuel F supplied to the gas turbine combustor 6, it is considered that effective heat recovery is achieved and the plant thermal efficiency is improved.

The present invention has been made in view of the above points, and an object of the present invention is to provide a combined cycle power plant that further improves the thermal efficiency of a plant by effectively utilizing a heat source.

[0025]

According to a first aspect of the present invention, there is provided a combined cycle power plant including a gas turbine plant and a steam turbine plant and a waste heat recovery boiler. In a combined cycle power plant including a fuel heating device for heating fuel supplied to a gas turbine combustor of the gas turbine plant, a lubricating oil plant is mounted on a bearing that supports a turbine rotor of the gas turbine plant and the steam turbine plant. And the heat generated from the lubricating oil plant is supplied to the fuel heating device.

In the combined cycle power plant according to the present invention, in order to achieve the above object, the lubricating oil plant axially supports a turbine rotor of a gas turbine plant and a steam turbine plant. It is provided with a lubricating oil circulation system for supplying and circulating lubricating oil to the bearing.

In order to achieve the above object, the combined cycle power plant according to the present invention is configured such that the lubricating oil circulation system uses the lubricating oil in the oil tank for the gas turbine and the steam turbine plant. It is a closed circuit which supplies a lubricating oil heated by the bearing to a bearing that supports the turbine rotor and supplies the lubricating oil to a fuel heating device to heat the fuel and then returns the fuel to the oil tank.

In order to achieve the above object, in the combined cycle power plant according to the present invention, the lubricating oil plant axially supports a turbine rotor of a gas turbine plant and a steam turbine plant. The lubricating oil circulation system supplies and circulates the lubricating oil to the bearing, and a cooling water circulation system that is provided in parallel with the lubricating oil circulation system and circulates cooling water that lowers the temperature of the lubricating oil.

In the combined cycle power plant according to the present invention, in order to achieve the above-mentioned object, the cooling water circulation system may be configured such that the temperature of lubricating oil is controlled by an oil cooler of the lubricating oil circulation system. It is characterized by a closed circuit in which the cooling water from the cooling water cooler whose temperature is raised when the temperature is lowered is supplied to the fuel heating device to heat the fuel and then returned to the oil cooler.

According to a sixth aspect of the present invention, there is provided a combined cycle power plant comprising a gas turbine plant combined with a steam turbine plant and an exhaust heat recovery boiler. In a combined cycle power plant having a fuel heating device for heating fuel supplied to a gas turbine combustor, a lubricating oil plant is provided on a bearing that supports a turbine rotor of the gas turbine plant and the steam turbine plant. A heat generated from the plant is supplied to the fuel heating device, and a gland seal system for sealing with a seal vapor is provided in a gland seal portion of the steam turbine of the steam turbine plant. Supply to fuel heating device It is obtained by the configuration.

In the combined cycle power plant according to the present invention, in order to achieve the above object, as described in claim 7, the gland seal system uses the seal steam after sealing the gland seal portion of the steam turbine. The fuel is supplied to the fuel heating device, and after heating the fuel, the fuel is returned to the condenser.

In order to achieve the above object, a combined cycle power plant according to the present invention is characterized in that a gas turbine plant is combined with a steam turbine plant and an exhaust heat recovery boiler. In a combined cycle power plant having a fuel heating device for heating fuel supplied to a gas turbine combustor, a lubricating oil plant is provided on a bearing that supports a turbine rotor of the gas turbine plant and the steam turbine plant. A configuration in which heat generated from a lubricating oil circulation system of a plant is supplied to the fuel heating device, a steam circulation system is provided in the exhaust heat recovery boiler, and steam in the steam circulation system is supplied to the fuel heating device. It is.

In the combined cycle power plant according to the present invention, in order to achieve the above object, as described in claim 9, the steam circulation system includes a part of the steam generated from the steam drum of the exhaust heat recovery boiler. After heating the fuel of the fuel heating device, the fuel is returned to the economizer of the exhaust heat recovery boiler.

According to a tenth aspect of the present invention, there is provided a combined cycle power plant comprising a gas turbine plant combined with a steam turbine plant and a waste heat recovery boiler. In a combined cycle power plant equipped with a fuel heating device for heating fuel supplied to a gas turbine combustor, a heating source for heating the fuel of the fuel heating device is formed by rotating a turbine rotor of the gas turbine plant and a steam turbine plant. This is a combination of a cooling water circulating system juxtaposed with a lubricating oil circulating system of a lubricating oil plant that supplies lubricating oil to supporting bearings, and a steam circulating system provided in the exhaust heat recovery boiler.

In order to achieve the above object, a combined cycle power plant according to the present invention is characterized in that a gas turbine plant is combined with a steam turbine plant and an exhaust heat recovery boiler. In a combined cycle power plant equipped with a fuel heating device for heating fuel supplied to a gas turbine combustor, a heating source for heating the fuel of the fuel heating device is formed by rotating a turbine rotor of the gas turbine plant and a steam turbine plant. This is a combination of a lubricating oil circulation system of a lubricating oil plant that supplies lubricating oil to a bearing to be supported, and a steam circulation system provided in the exhaust heat recovery boiler.

In order to achieve the above object, a combined cycle power plant according to the present invention is provided by combining a gas turbine plant with a steam turbine plant and an exhaust heat recovery boiler. In a combined cycle power plant equipped with a fuel heating device for heating fuel supplied to a gas turbine combustor, a heating source for heating the fuel of the fuel heating device is formed by rotating a turbine rotor of the gas turbine plant and a steam turbine plant. This is a combination of a cooling water circulation system juxtaposed with a lubricating oil circulation system of a lubrication oil plant that supplies lubricating oil to supporting bearings, and a turbine extraction system provided in a steam turbine of the steam turbine plant.

In order to achieve the above object, the combined cycle power plant according to the present invention is characterized in that the turbine bleed system uses bleed steam extracted from the middle stage of the steam turbine as a fuel heating device. After the fuel is heated, the fuel is returned to the condenser.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a combined cycle power plant according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic system diagram showing a first embodiment of a combined cycle power plant according to the present invention.

This combined cycle power plant 3
Reference numeral 0 denotes a configuration including a gas turbine plant 31, a steam turbine plant 32, an exhaust heat recovery boiler 33, and a lubricating oil plant 34.

The gas turbine plant 31 includes an air compressor 35, a gas turbine combustor 36, a gas turbine 37, and a fuel heating device 38. The air AR sucked by the air compressor 35 is pressurized, and the high pressure air is heated by fuel. The heated fuel F from the device 38 is added to the gas turbine combustor 36
Generates a combustion gas, and drives the gas turbine 37 using the combustion gas as a driving gas.

The steam turbine plant 32 includes a steam turbine 40, a condenser 41, a condensate pump 42, a deaerator 43, and a water supply pump 44 which are directly connected to a power generator 39. The steam is supplied from a waste heat recovery boiler 33. The turbine drive steam is subjected to expansion work in the steam turbine 40, and the generator 39 is rotated with the rotational torque generated during the expansion work to generate an electric output, and the turbine exhaust having completed the expansion work is restored. The condensed water is condensed by a water condenser 41 to be condensed, the condensed water is pressurized by a condensate pump 42, the dissolved oxygen is degassed by a deaerator 43 to supply water, and the supply water is pressurized again by a water supply pump 44 to be discharged. The heat is returned to the heat recovery boiler 33.

On the other hand, the exhaust heat recovery boiler 33 is provided with a superheater 45 and a steam drum 46 arranged from the upstream side to the downstream side along the flow of the exhaust heat (exhaust gas) G from the gas turbine 37. The evaporator 47 and the economizer 48 are accommodated in a casing 49, and the water supplied from the steam turbine plant 32 is heated by the economizer 48, and the heated water is flow-controlled by the control valve 50. Then, using the specific gravity of the heated water, the natural steam is naturally circulated in the evaporator 47 to produce saturated steam, and the saturated steam is heated again by the superheater 45 to generate superheated steam. To the steam turbine plant 32.

The lubricating oil plant 34 has an oil tank 5
1. A closed circuit lubricating oil circulation system 57 including an oil pump 52, an oil cooler 53, and a lubricating oil control valve 54. The lubricating oil circulation system 57 pressurizes the lubricating oil in the oil tank 51 with the oil pump 52 and outputs the lubricating oil to the gas turbine plant 3.
1 and the steam turbine plant 32 are supplied to bearings 56a and 56b which support a turbine rotor 55 which is directly connected to the shaft,
Here, the lubricating oil heated by the rotational friction heat of the turbine rotor 55 is guided to the fuel heating device 38 as a heat source, and after heating the fuel F, the cooled lubricating oil is returned to the oil tank 51. I have. The gas turbine plant 31
During the trip, the lubricating oil in the bearings 56a and 56b is flow-controlled by the lubricating oil control valve 54 via the lubricating oil circulation system 57, and its temperature is lowered by the oil cooler 53 and returned to the oil tank 51.

As described above, in this embodiment, the bearing 56
The lubricating oil heated in steps 56a and 56b is used as a heat source and guided to the fuel heating device 38 through the lubricating oil circulation system 57 to heat the fuel F, evaporate the fuel F, remove water vapor, and lose its latent heat. Since the supplied fuel F is supplied to the gas turbine combustor 36, combustion gas can be generated with a relatively small fuel flow rate as compared with the related art.

Therefore, according to this embodiment, since the combustion gas can be generated with a relatively small fuel flow rate, it is possible to effectively use the existing heat source without having to secure a special heat source for the fuel heating device. The plant thermal efficiency can be greatly improved as compared with the conventional case.

FIG. 2 is a schematic system diagram showing a second embodiment of the combined cycle power plant according to the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals.

In this embodiment, the lubricating oil plant 34 is combined with a lubricating oil circulating system 57 and a cooling water circulating system 61 so that the lubricating oil in the lubricating oil circulating system 57 is cooled by the cooling water of the cooling water circulating system 61. The fuel F of the fuel heating device 38 is heated using the heated cooling water as a heating source.

The cooling water circulation system 61 includes a cooling water pump 58,
The cooling water cooler 59 and the cooling water control valve 60 are configured in a closed circuit. The cooling water circulation system 61 includes an oil cooler 5
In step 3, when the temperature of the lubricating oil in the lubricating oil circulation system 57 is lowered, the temperature of the lubricating oil is increased by the cooling water pump 58 using the heated cooling water as a heating source.
After being guided to the fuel heating device 38 and heating the fuel F, the cooled cooling water is returned to the oil cooler 53. When the gas turbine plant 31 trips, the flow rate of the cooling water is controlled by the cooling water control valve 60, and is cooled by the cooling water cooler 59.

As described above, in the present embodiment, when heating the fuel F of the fuel heating device 38, the heated cooling water of the cooling water circulation system 61 used for cooling the lubricating oil of the lubricating oil circulation system 57 is used. Since the heat source is used, the heat can be effectively used.

Therefore, according to the present embodiment, the heat of heating the cooling water in the cooling water circulating system 61 is effectively used.
The plant thermal efficiency can be improved more than before.

FIG. 3 is a schematic system diagram showing a third embodiment of the combined cycle power plant according to the present invention. The same components as those of the first and second embodiments are denoted by the same reference numerals.

In the present embodiment, the lubricating oil circulation system 57 shown in the first embodiment is combined with the gland seal system 62, and the lubricating oil of the lubricating oil circulation system 57 and the sealing vapor of the gland seal system 62 are separated. Fuel heating device 38 as heating source
The fuel F is heated.

The gland seal system 62 includes the steam turbine 4
Ground seal portions 63a and 63b are provided on the shaft end of the shaft 0, and the exhaust heat recovery boiler 33 is provided on each of the ground seal portions 63a and 63b.
A part of the superheated steam from the superheater 45 is supplied, and the seal steam after sealing each of the gland seal portions 63a and 63b is guided to the fuel heating device 38, where the fuel F is heated, and then the condenser 41.

As described above, in this embodiment, the lubricating oil circulation system 57 and the gland seal system 62 are combined, and each system 5
Since the fuel F of the fuel heating device 38 is heated by the heat of 7, 62, further effective use of heat can be achieved.

FIG. 4 is a schematic system diagram showing a fourth embodiment of the combined cycle power plant according to the present invention. The same parts as those in the first to third embodiments are denoted by the same reference numerals.

In this embodiment, the cooling water circulation system 61 shown in the second embodiment and the gland seal system 62 shown in the third embodiment are combined, and the heated cooling water of the cooling water circulation system 61 and the gland seal system 62 are combined. Is used to heat the fuel F of the fuel heating device 38 using the sealing steam as a heating source.

Therefore, also in the present embodiment, the fuel F of the fuel heating device 38 is heated by the heated cooling water of the cooling water circulation system 61 and the sealing steam of the gland sealing system 62, so that the heat can be effectively used. it can.

FIG. 5 is a schematic system diagram showing a fifth embodiment of the combined cycle power plant according to the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals.

In the present embodiment, the lubricating oil circulation system 57 shown in the first embodiment is combined with the steam circulation system 64 of the exhaust heat recovery boiler 33, and the lubricating oil circulation system 57 and the high temperature lubricating oil and the steam circulation system are combined. Fuel heating device 3 using 64 steams as a heating source.
No. 8 is heated.

The steam circulation system 64 of the exhaust heat recovery boiler 33 includes a economizer 48, a control valve 50, a steam drum 46, an evaporator 47,
A flow control valve 65 is provided.
7, a part of the saturated steam guided to the superheater 45 is supplied to the fuel heating device 38 via the flow control valve 65, where the fuel F is heated. It is configured to return to the exit side. Since a large amount of steam for the heating source supplied from the steam circulation system 64 to the fuel heating device 38 is consumed, the heat transfer areas of the economizer 48 and the evaporator 47 are increased as compared with the conventional case.

As described above, in the present embodiment, the lubricating oil circulation system 57 and the steam circulation system 64 are combined, and the respective systems 57 and 6 are combined.
Since the fuel F of the fuel heating device 38 is heated by the heat of No. 4, the exhaust heat G which has conventionally been exhausted from the gas turbine plant 32 and cannot be recovered by the exhaust heat recovery boiler 33 can be sufficiently absorbed, and the lubricating oil can be absorbed. The heat can be effectively used together with the heat of the circulation system 57.

FIG. 6 is a schematic system diagram showing a sixth embodiment of the combined cycle power plant according to the present invention. The same parts as those in the first, second and fifth embodiments are denoted by the same reference numerals.

This embodiment is a combination of the cooling water circulation system 61 shown in the second embodiment and the steam circulation system 64 shown in the fifth embodiment. Fuel heating device 38 using the steam of
The fuel F is heated.

Therefore, also in this embodiment, since the fuel F of the fuel heating device 38 is heated by the heated cooling water of the cooling water circulation system 61 and the steam of the steam circulation system, the exhaust heat discharged from the gas turbine plant 32 is also heated. G can be sufficiently recovered and heat can be effectively used.

FIG. 7 is a schematic system diagram showing a seventh embodiment of the combined cycle power plant according to the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals.

In this embodiment, the lubricating oil circulation system 57 of the steam turbine plant 32 is combined with the lubricating oil circulation system 57 shown in the first embodiment, and the lubricating oil circulation system 57 is heated to a high temperature. The fuel F of the fuel heating device 38 is heated by using the turbine extraction air of the system 66 as a heating source.

The turbine bleed system 66 of the steam turbine plant 32 supplies the turbine bleed steam extracted from the middle stage of the steam turbine 40 to the fuel heating device 38, where the fuel F is heated. It is configured to return to the water dispenser 41.

As described above, in the present embodiment, the lubricating oil circulation system 57 and the turbine bleed system 66 are combined, and each system 5
Since the fuel F of the fuel heating device 38 is heated by the heat of 7, 66, the thermal efficiency of the plant can be significantly improved compared to the conventional art, in combination with the effective use of the heat.

FIG. 8 is a schematic system diagram showing an eighth embodiment of the combined cycle power plant according to the present invention. The same parts as those in the first, second and seventh embodiments are denoted by the same reference numerals.

In this embodiment, the cooling water circulation system 61 shown in the second embodiment and the turbine bleed system 6 shown in the seventh embodiment
6, and the fuel F of the fuel heating device 38 is heated using the heated cooling water of the cooling water circulation system 61 and the extracted steam of the turbine extraction system 66 as heating sources.

Therefore, also in this embodiment, since the fuel F of the fuel heating device 38 is heated by the heated cooling water of the cooling water circulation system 61 and the turbine bleed steam of the turbine bleed system 66, the plant can be effectively used together with the heat. Thermal efficiency can be greatly improved as compared with the conventional case.

[0073]

As described above, the combined cycle power plant according to the present invention includes at least one of a lubricating oil circulation system, a cooling water circulation system, a gland seal system, a steam circulation system, and a turbine extraction system. Combined, the fuel of the fuel heating device is heated using the heat of each system, so there is no risk of steaming as in the past, and the combined use of heat can significantly improve the plant thermal efficiency. it can.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram showing a first embodiment of a combined cycle power plant according to the present invention.

FIG. 2 is a schematic system diagram showing a second embodiment of a combined cycle power plant according to the present invention.

FIG. 3 is a schematic system diagram showing a third embodiment of the combined cycle power plant according to the present invention.

FIG. 4 is a schematic system diagram showing a fourth embodiment of the combined cycle power plant according to the present invention.

FIG. 5 is a schematic system diagram showing a fifth embodiment of the combined cycle power plant according to the present invention.

FIG. 6 is a schematic system diagram showing a sixth embodiment of the combined cycle power plant according to the present invention.

FIG. 7 is a schematic system diagram showing a seventh embodiment of the combined cycle power plant according to the present invention.

FIG. 8 is a schematic system diagram showing an eighth embodiment of a combined cycle power plant according to the present invention.

FIG. 9 is a schematic system diagram showing an embodiment of a conventional combined cycle power plant.

FIG. 10 is a schematic system diagram showing another embodiment of the conventional combined cycle power plant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combined cycle power plant 2 Gas turbine plant 3 Steam turbine plant 4 Exhaust heat recovery boiler 5 Air compressor 6 Gas turbine combustor 7 Gas turbine 8 Superheater 9 Steam drum 10 Evaporator 11 Energy saving device 12 Casing 13 Control valve 14 Power generation Machine 15 Steam turbine 15a Ground seal part 15b Ground seal part 16 Condenser 17 Condensate pump 18 Deaerator 19 Water supply pump 20 Turbine rotor 21a Bearing 21b Bearing 22 Lubricating oil plant 23 Oil tank 24 Oil pump 25 Oil cooler 26 Cooling Water cooler 27 Cooling water pump 28 Fuel heating device 30 Combined cycle power plant 31 Gas turbine plant 32 Steam turbine plant 33 Waste heat recovery boiler 34 Lubricating oil plant 35 Air compressor 36 Gas turbine combustion 37 Gas Turbine 38 Fuel Heating Device 39 Generator 40 Steam Turbine 41 Condenser 42 Condensate Pump 43 Deaerator 44 Feed Water Pump 45 Superheater 46 Steam Drum 47 Evaporator 48 Energy Saving 49 Casing 50 Control Valve 51 Oil Tank 52 Oil pump 53 Oil cooler 54 Lubricating oil control valve 55 Turbine rotor 56a Bearing 56b Bearing 57 Lubricating oil circulation system 58 Cooling water pump 59 Cooling water cooler 60 Cooling water control valve 61 Cooling water circulation system 62 Grand seal system 63a Ground seal portion 63b Gland seal part 64 Steam circulation system 65 Flow control valve 66 Turbine extraction system

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02C 7/224 F02C 7/224 F22B 1/18 F22B 1/18 K

Claims (13)

[Claims] 1. A combined cycle power plant comprising a gas turbine plant combined with a steam turbine plant and an exhaust heat recovery boiler and comprising a fuel heating device for heating fuel supplied to a gas turbine combustor of the gas turbine plant. A combined cycle power plant wherein a lubricating oil plant is provided in a bearing that supports a turbine rotor of a turbine plant and a steam turbine plant, and heat generated from the lubricating oil plant is supplied to the fuel heating device. 2. The lubricating oil plant includes a lubricating oil circulation system that supplies and circulates lubricating oil to a bearing that supports a turbine rotor of a gas turbine plant and a steam turbine plant. A combined cycle power plant as described. 3. The lubricating oil circulation system supplies lubricating oil in an oil tank to a bearing that supports a turbine rotor of a gas turbine and a steam turbine plant, and supplies lubricating oil heated by the bearing to a fuel heating device. 3. The combined cycle power plant according to claim 2, wherein the closed circuit is a closed circuit that returns fuel to the oil tank after heating the fuel. 4. A lubricating oil plant includes a lubricating oil circulation system that supplies and circulates lubricating oil to bearings that support a turbine rotor of a gas turbine plant and a steam turbine plant, and is provided in parallel with the lubricating oil circulation system. The combined cycle power plant according to claim 1, further comprising a cooling water circulation system that circulates cooling water that lowers the temperature of the lubricating oil. 5. The cooling water circulation system heats the fuel by supplying cooling water from the cooling water cooler, which has been heated when the temperature of the lubricating oil is lowered by the oil cooler of the lubricating oil circulation system, to the fuel heating device. The combined cycle power plant according to claim 4, wherein the closed circuit is a closed circuit that returns to the oil cooler after the operation. 6. A combined cycle power plant comprising a gas turbine plant combined with a steam turbine plant and an exhaust heat recovery boiler, and comprising a fuel heating device for heating fuel supplied to a gas turbine combustor of the gas turbine plant. A lubricating oil plant is provided on a bearing that supports a turbine rotor of a turbine plant and a steam turbine plant, heat generated from the lubricating oil plant is supplied to the fuel heating device, and a gland seal portion of a steam turbine of the steam turbine plant is provided. A combined cycle power plant, wherein a ground seal system for sealing with a seal steam is provided in the fuel cell system, and the seal steam after sealing the ground seal system is supplied to the fuel heating device. 7. The gland seal system is characterized in that a seal steam after sealing a gland seal portion of a steam turbine is supplied to a fuel heating device, and the fuel is heated and then returned to a condenser. A combined cycle power plant according to claim 6. 8. A combined cycle power plant comprising a gas turbine plant combined with a steam turbine plant and an exhaust heat recovery boiler and comprising a fuel heating device for heating fuel supplied to a gas turbine combustor of the gas turbine plant. A lubricating oil plant is provided on a bearing that supports a turbine rotor of a turbine plant and a steam turbine plant, and heat generated from a lubricating oil circulation system of the lubricating oil plant is supplied to the fuel heating device, and the exhaust heat recovery boiler A combined cycle power plant comprising: a steam circulation system; and steam supplied from the steam circulation system is supplied to the fuel heating device. 9. The steam circulation system is configured to heat a part of the steam generated from the steam drum of the exhaust heat recovery boiler, fuel the fuel heating device, and then return the fuel to the economizer of the exhaust heat recovery boiler. The combined cycle power plant according to claim 8, wherein: 10. A combined cycle power plant comprising a gas turbine plant combined with a steam turbine plant and an exhaust heat recovery boiler and comprising a fuel heating device for heating fuel supplied to a gas turbine combustor of the gas turbine plant. A heating source for heating the fuel of the heating device, a cooling water circulation system juxtaposed to a lubrication oil circulation system of a lubrication oil plant that supplies lubrication oil to bearings that support the turbine rotor of the gas turbine plant and the steam turbine plant, A combined cycle power plant characterized by combining a steam circulation system provided in the exhaust heat recovery boiler. 11. A combined cycle power plant comprising a gas turbine plant combined with a steam turbine plant and an exhaust heat recovery boiler and comprising a fuel heating device for heating fuel supplied to a gas turbine combustor of the gas turbine plant. A heating source for heating the fuel of the heating device is provided in the lubricating oil circulation system of the lubricating oil plant that supplies lubricating oil to bearings that support the turbine rotor of the gas turbine plant and the steam turbine plant, and the exhaust heat recovery boiler. Combined cycle power plant characterized by combining with a steam circulation system. 12. A combined cycle power plant comprising a gas turbine plant combined with a steam turbine plant and an exhaust heat recovery boiler, and comprising a fuel heating device for heating fuel supplied to a gas turbine combustor of the gas turbine plant. A heating source for heating the fuel of the heating device, a cooling water circulation system juxtaposed to a lubrication oil circulation system of a lubrication oil plant that supplies lubrication oil to bearings that support the turbine rotor of the gas turbine plant and the steam turbine plant, A combined cycle power plant wherein the steam turbine of the steam turbine plant is provided with a turbine bleed system. 13. The turbine bleed system according to claim 12, wherein the bleed steam extracted from the middle stage of the steam turbine is heated in the fuel heating device and then returned to the condenser. Combined cycle power plant.