JP7059347B2 - Waste heat recovery plant and combined cycle plant - Google Patents

Description

The present disclosure relates to a waste heat recovery plant and a combined cycle plant.

In a combined cycle plant equipped with a gas turbine and a steam turbine, an exhaust heat recovery boiler may be connected in order to effectively utilize the heat of the exhaust gas exhausted from the gas turbine.

As such a combined cycle plant, for example, there is a plant described in the following Patent Document 1. The plant of Patent Document 1 is provided with an exhaust heat recovery device as an exhaust heat recovery boiler for effectively utilizing the heat of the exhaust gas. This waste heat recovery device has a superheater, an evaporator, and an economizer (economizer). In this exhaust heat recovery device, high-temperature exhaust gas is supplied in the order of a superheater, an evaporator, and an economizer, and the heat of the exhaust gas is used to generate high-temperature and high-pressure steam, which is supplied to the steam turbine. are doing. Further, in this waste heat recovery device, a part of the hot water generated by the economizer is supplied to the flasher to generate low-pressure steam. The low-pressure steam generated by the flasher is supplied to the middle stage of the steam turbine and used to drive the steam turbine.

Japanese Unexamined Patent Publication No. 2011-196191

By the way, in the steam turbine used in such a plant, the pressure becomes very low as it approaches the final stage, and fine water droplets (drain) are generated in the main steam flowing in the main flow path. Most of these fine water droplets flow through the main flow path together with steam, but some of them adhere to the blade surface due to inertia and form a liquid film. After the liquid film moves to the trailing edge of the blade, it scatters again as coarse water droplets in the main flow path, and the water droplets collide with the moving blade rotating at high speed. This causes erosion that erodes the wing surface. Therefore, in steam turbines, there is a desire to suppress the occurrence of such erosion.

The present invention has been made in order to meet the above demands, and an object of the present invention is to provide a steam turbine system and a combined cycle plant capable of suppressing the occurrence of erosion.

In the combined cycle plant according to one aspect of the present invention, a steam turbine in which a main flow path through which main steam flows is formed, a saturated steam generator that generates saturated steam, and an exhaust that generates steam by the heat of exhaust gas. The steam turbine includes a heat recovery boiler and a water supply system for supplying water to the exhaust heat recovery boiler, the steam turbine drives the steam generated in the exhaust heat recovery boiler as the main steam, and the saturated steam generator , The flash steam generated by flushing the water generated in the exhaust heat recovery boiler is generated as the saturated steam, and the condensed water generated by flushing the water is heated by a heat source other than the exhaust gas to saturate. The exhaust heat recovery plant and the gas turbine, in which steam is sent to the steam turbine, are provided, and the exhaust gas of the gas turbine is supplied to the exhaust heat recovery boiler of the exhaust heat recovery plant, and the exhaust heat recovery boiler is provided. Is generated steam by the heat of the exhaust gas of the gas turbine, and the heat obtained by cooling the compressed air or the extracted air for cooling the components of the gas turbine is used as a heat source other than the exhaust gas .
In the exhaust heat recovery plant according to one aspect of the present invention, a steam turbine in which a main flow path through which main steam flows is formed, a saturated steam generator that generates saturated steam, and a steam generated by the heat of exhaust gas. The exhaust heat recovery boiler is provided with a water supply system for supplying water to the exhaust heat recovery boiler, and a heat exchanger provided in the water supply system. The steam turbine is a steam generated by the exhaust heat recovery boiler. Is driven as the main steam, the saturated steam generation unit generates flash steam as the saturated steam by flushing the water generated in the exhaust heat recovery boiler, and the heat exchanger generates the exhaust from the water supply system . The water supplied to the heat recovery boiler is heated by a heat source other than the exhaust gas, and then sent to the exhaust heat recovery boiler. The exhaust heat recovery boiler heats the water received from the heat exchanger with the exhaust gas. A generator that is exchanged and heated, and a part of it is sent to the saturated steam generator as water generated in the exhaust heat recovery boiler, and as the heat exchanger, power is generated by driving the steam turbine or other equipment. From a generator cooler that cools the cooling medium and heats the water by heat exchange between the cooling medium that cools the components and the water, and a bearing that rotatably supports the steam turbine or other device. A lubricating oil cooler that heats the lubricating oil and heats the water by exchanging heat between the lubricating oil and the water is provided, and the generator cooler and the lubricating oil cooler are the water supply. Along the flow of the water in the system, the generator cooler and the lubricating oil cooler are provided in this order .
In the combined cycle plant according to one aspect of the present invention, a steam turbine in which a main flow path through which main steam flows is formed, a saturated steam generator that generates saturated steam, and exhaust that generates steam by the heat of exhaust gas. The steam turbine includes a heat recovery boiler, a water supply system that supplies water to the exhaust heat recovery boiler, and a heat exchanger provided in the water supply system, and the steam turbine uses the steam generated by the exhaust heat recovery boiler. Driven as the main steam, the saturated steam generator generates flash steam as the saturated steam by flushing the water generated in the exhaust heat recovery boiler, and the heat exchanger uses the water other than the exhaust gas. After heating with a heat source, it is sent to the exhaust heat recovery boiler, and the exhaust heat recovery boiler heats the water received from the heat exchanger by exchanging heat with the exhaust gas, and partially recovers the exhaust heat. An exhaust heat recovery plant that sends water generated in the boiler to the saturated steam generation unit and a gas turbine are provided, and the exhaust gas of the gas turbine is supplied to the exhaust heat recovery boiler of the exhaust heat recovery plant. The exhaust heat recovery boiler generates steam by the heat of the exhaust gas of the gas turbine, and as the heat exchanger, heat exchanges the first cooling medium for cooling the air sucked by the gas turbine with the water. The second cooling medium is cooled by exchanging heat between the intake cooler that cools the first cooling medium and heats the water, and the second cooling medium that cools the components of the gas turbine and the water. The third is a heat exchange between the water and the cooling air cooler that heats the water and the third cooling medium that cools the components of the steam turbine or the generator that generates power by driving the gas turbine. The lubricating oil is cooled by heat exchange between the water and the lubricating oil from the generator cooler that cools the cooling medium and heats the water and the bearing that rotatably supports the steam turbine or the gas turbine. A lubricating oil cooler that heats the water together with the water is provided, and the two or more types of the heat exchangers are the intake air cooler along the flow of the water in the water supply system. , The generator cooler, the lubricating oil cooler, and the cooling air cooler are provided in this order .
The exhaust heat recovery plant according to one aspect of the present invention generates steam by the heat of exhaust gas, a steam turbine in which a main flow path through which main steam flows is formed, a saturated steam generation unit that generates saturated steam, and an exhaust heat recovery plant. The exhaust heat recovery boiler and a water supply system for supplying water to the exhaust heat recovery boiler are provided, and the steam turbine drives the steam generated in the exhaust heat recovery boiler as the main steam, and the saturated steam generation unit. Further comprises a water supply heater that generates flash steam obtained by flushing the water generated in the exhaust heat recovery boiler as the saturated steam and heats the water flowing through the water supply system with a heat source other than the exhaust gas. The steam generation unit sends the condensed water generated by flushing the water to the water supply system, and the water supply system sends the condensed water to the exhaust heat recovery boiler together with the water after heating with the water supply heater. The water supply heater cools the medium and heats the water by exchanging heat with a medium other than the exhaust gas as a heat source, and the condensed water is supplied in the water supply system. It joins the water heated by the water supply heater .
The exhaust heat recovery plant according to one aspect of the present invention generates steam by the heat of exhaust gas, a steam turbine in which a main flow path through which main steam flows is formed, a saturated steam generator that generates saturated steam, and an exhaust heat recovery plant. The exhaust heat recovery boiler is provided with a water supply system for supplying water to the exhaust heat recovery boiler, and the steam turbine drives the steam generated in the exhaust heat recovery boiler as the main steam to generate the saturated steam. Generates flash steam obtained by flushing the water generated in the waste heat recovery boiler as the saturated steam, and at least among the water flowing through the water supply system or the condensed water generated by flushing the water. One is heated by a heat source other than the exhaust gas, the saturated steam is sent to the steam turbine, and the exhaust heat recovery boiler heats the water by exchanging heat between the exhaust gas and the water. A low-temperature heat exchanger that cools the exhaust gas, a coal-saving device that generates low-pressure heated water by exchanging heat between the exhaust gas, the condensed water, and the water heated by the low-temperature heat exchanger. It has an evaporator that heats the exhaust gas and the low-pressure heated water to heat the low-pressure heated water and cool the exhaust gas, and the coal saver and the evaporator are the same. The coal saver and the evaporator are arranged in this order from the downstream side to the upstream side of the exhaust gas flow, and a part of the low-pressure heated water generates the saturated steam as the water generated in the exhaust heat recovery boiler. Sent to the department .
In the exhaust heat recovery plant according to one aspect of the present invention, the water supply system supplies the water having a temperature lower than the dew point temperature of the exhaust gas introduced into the low temperature heat exchanger to the low temperature heat exchanger. May be good .
In the exhaust heat recovery plant according to one aspect of the present invention, the low temperature heat exchanger may increase the amount of heat recovered from the exhaust gas by partially condensing the water content in the exhaust gas .
The combined cycle according to one aspect of the present invention includes the exhaust heat recovery plant and the gas turbine, and the exhaust gas of the gas turbine is supplied to the exhaust heat recovery boiler of the exhaust heat recovery plant, and the exhaust is exhausted. The heat recovery steam generator generates steam by the heat of the exhaust gas of the gas turbine.

According to the present invention, the occurrence of erosion can be suppressed.

It is a system diagram of the combined cycle plant in the 1st Embodiment which concerns on this invention. It is a system diagram of the combined cycle plant in the 2nd Embodiment which concerns on this invention. It is sectional drawing of the main part explaining the area around the wet region of the steam turbine in the 3rd Embodiment which concerns on this invention. It is sectional drawing of the main part explaining the area around the wet region of the steam turbine in 4th Embodiment which concerns on this invention. It is sectional drawing of the stationary blade in the 4th Embodiment which concerns on this invention. It is a system diagram of the combined cycle plant in the 5th Embodiment which concerns on this invention. It is a system diagram of the combined cycle plant in the 6th Embodiment which concerns on this invention. It is a system diagram of the combined cycle plant in the 7th Embodiment which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<< First Embodiment >>
A first embodiment of the combined cycle plant 1 according to the present invention will be described with reference to FIG. As shown in FIG. 1, the combined cycle plant 1 of the present embodiment is from a gas turbine 10, a first generator 15 that generates electricity by driving the gas turbine 10, an exhaust heat recovery boiler 100, and an exhaust heat recovery boiler 100. It includes a chimney 129 that discharges exhaust gas to the atmosphere, a flue 128 that connects the exhaust heat recovery boiler 100 and the chimney 129, a steam turbine system 200, and a water supply system 70.

The gas turbine 10 is a turbine driven by a compressor 11 that compresses air A, a combustor 20 that burns fuel in the air A compressed by the compressor 11 to generate combustion gas, and a high-temperature and high-pressure combustion gas. It is equipped with 30 and.

As shown in FIG. 1, the turbine 30 and the compressor 11 are arranged on the same axis and are connected to each other by a gas turbine rotor 13. The rotor of the first generator 15 is connected to the gas turbine rotor 13. The rotors of the gas turbine rotor 13 and the first generator 15 are rotatably supported by the first bearing 14.

The steam turbine system 200 of the present embodiment includes a plurality of steam turbines 60, a second generator 230 that generates power by driving the plurality of steam turbines 60, and a water recovery device 240 that returns steam exhausted from the steam turbine 60 to water. And a saturated steam generation unit 210.

The steam turbine system 200 of the present embodiment has, as the steam turbine 60, a high-pressure steam turbine 601, a medium-pressure steam turbine 602, and a low-pressure steam turbine 603. The configuration of the steam turbine 60 of the present embodiment will be described in detail by taking a low-pressure steam turbine 603 as an example.

The low-pressure steam turbine 603 is formed with a main flow path C through which main steam flows. The main flow path C is a space inside the low-pressure steam turbine 603 sandwiched between the steam inlet and the steam outlet. The main steam is superheated steam when it flows into the main flow path C from the steam inlet. Superheated steam is steam whose temperature is equal to or higher than the saturation temperature (100 ° C. at atmospheric pressure). In addition, the pressure of the main steam decreases and expands toward the downstream side from the steam inlet toward the steam outlet, the dryness decreases and the steam becomes dry and saturated, and further expands to contain fine water droplets (drain). It becomes damp steam. Wet steam is steam whose temperature is saturated and whose dryness is more than 0% and less than 100%.

The low-pressure steam turbine 603 includes a steam turbine rotor 61 that rotates about an axis, a steam turbine casing 64 that covers the steam turbine rotor 61, and a plurality of stationary blade rows 65 provided on the inner peripheral surface of the steam turbine casing 64. And have. The plurality of stationary blade rows 65 are arranged at intervals in the axial direction in which the axis extends. Each of the stationary blade rows 65 has a plurality of stationary blades 650 arranged in the circumferential direction about the axis line. The steam turbine rotor 61 has a rotor shaft 62 extending in the axial direction about an axis, and a plurality of blade rows 63 fixed to the outer periphery of the rotor shaft 62. Each of the plurality of rotor blade rows 63 is arranged on the downstream side in the axial direction of any one of the stationary blade rows 65. Each blade row 63 has a plurality of blades 630 arranged in the circumferential direction about the axis. The moving blades 630 and the stationary blades 650 are arranged in the main flow path C. One "stage" is composed of one rotor blade row 63 and the stationary blade rows 65 adjacent to each other on the upstream side of the rotor blade row 63. The low-pressure steam turbine 603 is provided with a blade row 63 and a stationary blade row 65 having a large number of stages (four stages in this embodiment). Further, in the low pressure steam turbine 603, the blade heights of the moving blades 630 and the stationary blades 650 (the length of the blades in the direction orthogonal to the rotor shaft 62) increase from the upstream side to the downstream side in the flow direction of the main flow path C. It is configured to be.
The high-pressure steam turbine 601 and the medium-pressure steam turbine 602 also have the same configuration.

The steam turbine rotors of the high-pressure steam turbine 601, the medium-pressure steam turbine 602, and the low-pressure steam turbine 603 are arranged on the same axis and connected to each other to form one steam turbine rotor. The rotor of the second generator 230 is connected to this one steam turbine rotor. The steam turbine rotor and the rotor of the second generator 230 are rotatably supported by the second bearing 220.

In this embodiment, one second generator 230 is provided for a total of three steam turbines 60, that is, a high-pressure steam turbine 601, a medium-pressure steam turbine 602, and a low-pressure steam turbine 603. However, in the steam turbine system 200, generators may be provided in the high pressure steam turbine 601, the medium pressure steam turbine 602, and the low pressure steam turbine 603, respectively.

The condenser 240 of the present embodiment returns the steam exhausted from the low-pressure steam turbine 603 to water.

The saturated steam generation unit 210 generates saturated steam from the supplied water. The saturated steam generation unit 210 sends the saturated steam to the wet region C1 of the main flow path C in which the main steam is in a wet state. In the saturated steam generation unit 210 of the present embodiment, water is supplied from the exhaust heat recovery boiler 100. The saturated steam generation unit 210 generates saturated steam from the supplied water.

Here, the wet state means that the dryness of the main steam flowing in the main flow path C exceeds 0% and is less than 100%, and the main steam is a wet steam. There is. In the low-pressure steam turbine 603 of the present embodiment, the pressure and temperature of the main steam flowing from the steam inlet to the steam outlet decrease. As a result, in the low-pressure steam turbine 603, the temperature in the main flow path C becomes the saturation temperature near the final stage, and the dryness is also less than 100%. This temperature becomes the saturation temperature, and the space of the main flow path C whose dryness is less than 100% is the wet region C1. The wet region C1 of the present embodiment is, for example, a space near the final stage in the main flow path C of the low-pressure steam turbine 603, and is a space of the main flow path C where the pressure is below atmospheric pressure and the dryness is several percent lower than 100%. do.

The saturated steam generation unit 210 of the present embodiment generates low-pressure saturated steam sent to the wet region C1 and high-pressure saturated steam having a higher pressure than the low-pressure saturated steam as saturated steam. The saturated steam generation unit 210 sends the high-pressure saturated steam to the upstream region of the wet region C1 of the main flow path C. The saturated steam generation unit 210 has a flasher that depressurizes water to generate flash steam. In the present embodiment, the saturated steam generation unit 210 has not a single-stage flasher, but a multi-stage flasher that makes the supplied water flash steam a plurality of times while gradually reducing the pressure. The saturated steam generation unit 210 supplies saturated steam having a pressure corresponding to the pressure of the main steam in the main flow path C of the low-pressure steam turbine 603 at the position where the saturated steam is sent. Therefore, the saturated steam generation unit 210 supplies saturated steam at different pressures and temperatures depending on the position where the saturated steam is sent. The saturated steam generation unit 210 of the present embodiment has a first flasher 211, a second flasher 212, a third flasher 213, and a fourth flasher 214. Therefore, the saturated steam generation unit 210 of the present embodiment generates flash steam four times.

The first flasher 211 flushes the water supplied from the low pressure economizer 103 described later to generate high pressure saturated steam. The first flasher 211 supplies the high-pressure saturated steam to the upstream side of the wet region C1. Specifically, the first flasher 211 supplies high-pressure saturated steam to the steam inlet of the low-pressure steam turbine 603. Therefore, the first flasher 211 generates the first saturated steam having a saturation temperature at the same pressure as the main steam supplied to the steam inlet of the low pressure steam turbine 603 as the high pressure saturated steam. For example, when the main steam at the steam inlet of the low-pressure steam turbine 603 is about 5.2 at 280 ° C., the first saturated steam generated by the first flasher 211 is about 5.2 at at 150 ° C. The first flasher 211 supplies the first condensed water, which is condensed water generated by flushing the water from the low-pressure economizer 103, to the second flasher 212.

The second flasher 212 flushes the first condensed water supplied from the first flasher 211. The second flasher 212 produces the second saturated steam as a high-pressure saturated steam having a lower pressure than the first saturated steam. The second flasher 212 supplies the second saturated steam to the upstream region from the wet region C1. The second flasher 212 supplies the second saturated steam to a region downstream of the region where the first saturated steam is supplied from the first flasher 211 in the main flow path C (for example, the second stage). Therefore, the second flasher 212 generates the second saturated steam having the saturation temperature at the same pressure as the main steam in the downstream region from the steam inlet of the low pressure steam turbine 603. For example, when the main steam of the second stage of the low pressure steam turbine 603 is about 2.7 at, 220 ° C., the second saturated steam generated by the second flasher 212 is about 2.7 at, 130 ° C. The second flasher 212 supplies the second condensed water, which is the condensed water generated by flushing the first condensed water, to the third flasher 213.

The third flasher 213 flushes the second condensed water supplied from the second flasher 212. The third flasher 213 produces the third saturated steam as a high-pressure saturated steam having a lower pressure than the second saturated steam. The third flasher 213 supplies the third saturated steam to the upstream region from the wet region C1. The third flasher 213 supplies the third saturated steam to a region downstream of the region where the second saturated steam is supplied from the second flasher 212 in the main flow path C (for example, the third stage). Therefore, the third flasher 213 generates the third saturated steam having a saturation temperature at a pressure equivalent to that of the main steam in the region downstream of the region to which the second saturated steam is supplied in the main flow path C. For example, when the main steam of the third stage of the low-pressure steam turbine 603 is about 1.1 ata and 140 ° C., the third saturated steam generated by the third flasher 213 is 1.1 ata and a little over 100 ° C. The third flasher 213 supplies the third condensed water, which is the condensed water generated by flushing the second condensed water, to the fourth flasher 214.

The fourth flasher 214 flushes the third condensed water supplied from the third flasher 213. The fourth flasher 214 produces the fourth saturated steam as a low-pressure saturated steam having a lower pressure than the third saturated steam. The fourth flasher 214 supplies the fourth saturated steam to the wet region C1. The fourth flasher 214 supplies the fourth saturated steam to a region downstream of the region where the third saturated steam is supplied from the third flasher 213 in the main flow path C (the final stage in this embodiment). Therefore, the fourth flasher 214 produces a fourth saturated steam having a saturation temperature at a pressure equivalent to that of the main steam in the wet region C1. For example, when the main steam in the wet region C1 near the final stage of the low-pressure steam turbine 603 is about 0.4 ata and 75 ° C., the fourth saturated steam generated by the fourth flasher 214 is 0.4 ata and 75 ° C. It becomes a degree. The fourth flasher 214 uses the fourth condensed water, which is the condensed water generated by flushing the third condensed water, together with the water supplied from the low temperature heat exchanger 102 to the low pressure economizer 103, which will be described later, together with the low pressure node. Send to the charcoal machine 103.

The water supply system 70 sends the water in the condenser (water supply source) 240 as water supply to the exhaust heat recovery boiler 100. The water supply system 70 supplies water having a temperature lower than the dew point temperature of the exhaust gas discharged from the exhaust heat recovery boiler 100. The water supply system 70 has a water supply line 71 that connects the condenser 240 and the exhaust heat recovery boiler 100, and a water supply pump 79 that sends the water in the condenser 240 to the exhaust heat recovery boiler 100. The water supply line 71 connects the condenser 240 and the low temperature heat exchanger 102 described later. The water supply line 71 is provided with a water supply pump 79.

The exhaust heat recovery boiler 100 includes a boiler outer frame 101, a low temperature heat exchanger 102, a low pressure economizer 103, a low pressure economizer 104, a low pressure superheater 105, a medium pressure reheater 106, and a high pressure economizer. It has a vessel 107, a high-pressure evaporator 108, and a high-pressure superheater 109.

The boiler outer frame 101 is connected to the exhaust port of the turbine 30 and the flue 128. Therefore, the combustion gas obtained by rotating the gas turbine rotor 13 flows into the boiler outer frame 101 as exhaust gas. This exhaust gas passes through the boiler outer frame 101, passes through the flue 128 and the chimney 129, and is released into the atmosphere. In the present embodiment, the chimney 129 side of the boiler outer frame 101 is the downstream side of the exhaust gas flow, and the turbine 30 side opposite to the chimney 129 side is the upstream side.

In the exhaust heat recovery boiler 100 of the present embodiment, the low pressure economizer 103, the low pressure evaporator 104, the low pressure superheater 105, the medium pressure reheater 106, the high pressure economizer 107, the high pressure evaporator 108, and the high pressure superheater 109 Is provided in the boiler outer frame 101. Here, the low-pressure economizer 103, the low-pressure evaporator 104, the low-pressure superheater 105, the high-pressure economizer 107, the high-pressure evaporator 108, the high-pressure superheater 109, and the medium-pressure reheater 106 are exhausted in the above order. It is lined up from the downstream side to the upstream side of the gas. The low temperature heat exchanger 102 is arranged in the flue 128. The low temperature heat exchanger 102 may be located in the boiler outer frame 101 and on the downstream side of the low pressure economizer 103. Further, the low temperature heat exchanger 102 may be omitted.

The water supply from the condenser 240 flows into the low temperature heat exchanger 102. Exhaust gas that has passed through the low-pressure economizer 103 flows into the low-temperature heat exchanger 102. The low temperature heat exchanger 102 heats and exchanges the exhaust gas passing through the flue 128 with the water supply to heat the water supply while cooling the exhaust gas. The low temperature heat exchanger 102 sends the heated water supply to the low pressure economizer 103. The low temperature heat exchanger 102 and the low pressure economizer 103 are connected by a first heated water line 111.

Heated water supply flows into the low-pressure economizer 103. Exhaust gas that has passed through the low-pressure evaporator 104 flows into the low-pressure economizer 103. The low-pressure economizer 103 heats the exhaust gas and the water supply heated by the low-temperature heat exchanger 102, and heats the water supply to generate low-pressure heated water. The low-pressure economizer 103 sends the generated low-pressure heated water to the low-pressure evaporator 104 and the high-pressure economizer 107.

The low-pressure economizer 103 and the low-pressure evaporator 104 are connected by a second heated water line 112. The second heated water line 112 is provided with a first evaporator water supply valve 112a. The first evaporator water supply valve 112a reduces the pressure of the low-pressure heated water. The low-pressure economizer 103 and the high-pressure economizer 107 are connected by a third heated water line 113. A high-pressure pump 115 is provided in the third heating water line 113. The high-pressure pump 115 boosts the low-pressure heated water to generate high-pressure heated water. The high-pressure pump 115 sends the generated high-pressure heating water to the high-pressure economizer 107.

Low-pressure heating water flows into the low-pressure evaporator 104. Exhaust gas that has passed through the low-pressure superheater 105 flows into the low-pressure evaporator 104. The low-pressure evaporator 104 heats the low-pressure heated water by exchanging heat between the low-pressure heated water heated by the low-pressure economizer 103 and the exhaust gas to generate low-pressure steam. The low pressure evaporator 104 sends the generated low pressure steam to the low pressure superheater 105. The low-pressure evaporator 104 and the low-pressure superheater 105 are connected by a first steam line 121.

Low-pressure steam flows into the low-pressure superheater 105. Exhaust gas that has passed through the high-pressure economizer 107 flows into the low-pressure superheater 105. The low-pressure superheater 105 heats the low-pressure steam by exchanging heat between the low-pressure steam and the exhaust gas. The low-pressure superheater 105 sends the superheated low-pressure steam to the low-pressure steam turbine 603 as low-pressure superheated steam.

High-pressure heating water flows into the high-pressure economizer 107. Exhaust gas that has passed through the high-pressure evaporator 108 flows into the high-pressure economizer 107. The high-pressure economizer 107 exchanges heat between the high-pressure heating water and the exhaust gas to further heat the high-pressure heating water. The high-pressure economizer 107 sends the heated high-temperature heated water to the high-pressure evaporator 108. The high-pressure economizer 107 and the high-pressure evaporator 108 are connected by a fourth heated water line 114. The fourth heated water line 114 is provided with a second evaporator water supply valve 114a. The second evaporator water supply valve 114a decompresses the heated high-temperature heated water.

The heated high-pressure heating water flows into the high-pressure evaporator 108. Exhaust gas that has passed through the high-pressure superheater 109 flows into the high-pressure evaporator 108. The high-pressure evaporator 108 heats the high-pressure heated water by exchanging heat between the high-pressure heated water heated by the high-pressure economizer 107 and the exhaust gas, and generates high-pressure steam. The high-pressure evaporator 108 sends the generated high-pressure steam to the high-pressure superheater 109. The high-pressure evaporator 108 and the high-pressure superheater 109 are connected by a second steam line 122.

High-pressure steam flows into the high-pressure superheater 109. Exhaust gas that has passed through the medium pressure reheater 106 flows into the high pressure superheater 109. The high-pressure superheater 109 heats the high-pressure steam by exchanging heat between the high-pressure steam and the exhaust gas. The high-pressure superheater 109 sends the superheated high-pressure steam to the high-pressure steam turbine 601 as high-pressure superheated steam.

The main steam exhausted from the high-pressure steam turbine 601 flows into the medium-pressure reheater 106. Exhaust gas discharged from the turbine 30 flows into the medium pressure reheater 106. The medium-pressure reheater 106 exchanges heat between the main steam exhausted from the high-pressure steam turbine 601 and the exhaust gas, superheats the main steam, and sends it to the medium-pressure steam turbine 602 as medium-pressure superheated steam.

The high-pressure superheater 109 and the steam inlet of the high-pressure steam turbine 601 are connected by a high-pressure steam line 131. The steam outlet of the high-pressure steam turbine 601 and the medium-pressure reheater 106 are connected by a high-pressure exhaust line 132. The medium pressure reheater 106 and the steam inlet of the medium pressure steam turbine 602 are connected by a medium pressure steam line 133. The steam outlet of the medium pressure steam turbine 602 and the steam inlet of the low pressure steam turbine 603 are connected by a medium pressure exhaust line 134. The medium pressure exhaust line 134 and the low pressure superheater 105 are connected by a low pressure steam line 135. The steam outlet of the low-pressure steam turbine 603 and the condenser 240 are connected by a low-pressure exhaust line 136.

The low pressure economizer 103 and the first flasher 211 are connected by a first flasher water supply line 141. The first flasher water supply line 141 of the present embodiment is connected to the second heated water line 112 and indirectly connected to the low pressure economizer 103. The first flasher water supply line 141 is provided with a first flasher water supply valve 141a that controls a water supply state to the first flasher 211.

The first flasher 211 and the low pressure steam turbine 603 are connected by a first saturated steam line 151. The first saturated steam line 151 is connected to the medium pressure exhaust line 134 on the downstream side of the connection portion between the medium pressure exhaust line 134 and the low pressure steam line 135.

The first flasher 211 and the second flasher 212 are connected by a second flasher water supply line 142. The second flasher water supply line 142 is provided with a second flasher water supply valve 142a that controls the water supply state to the second flasher 212.

The second flasher 212 and the low pressure steam turbine 603 are connected by a second saturated steam line 152. The second saturated steam line 152 is connected so as to communicate with the main flow path C of the low pressure steam turbine 603 near the second stage. The second saturated steam line 152 of the first embodiment is connected to the upstream side of the second stage stationary blade 650 and to communicate with the main flow path C on the downstream side of the first stage moving blade 630 .

The second flasher 212 and the third flasher 213 are connected by a third flasher water supply line 143. The third flasher water supply line 143 is provided with a third flasher water supply valve 143a that controls the water supply state to the third flasher 213.

The third flasher 213 and the low pressure steam turbine 603 are connected by a third saturated steam line 153. The third saturated steam line 153 is connected so as to communicate with the main flow path C of the low pressure steam turbine 603 near the third stage. The third saturated steam line 153 of the first embodiment is connected to the upstream side of the third-stage stationary blade 650 and to communicate with the main flow path C on the downstream side of the second-stage rotor blade 630 . ..

The third flasher 213 and the fourth flasher 214 are connected by a fourth flasher water supply line 144. The fourth flasher water supply line 144 is provided with a fourth flasher water supply valve 144a that controls the water supply state to the fourth flasher 214.

The fourth flasher 214 and the low pressure steam turbine 603 are connected by a fourth saturated steam line 154. The fourth saturated steam line 154 is connected so as to communicate with the main flow path C of the low pressure steam turbine 603 near the final stage. The fourth saturated steam line 154 of the first embodiment is connected to the upstream side of the fourth stage stationary blade 650 and to communicate with the main flow path C on the downstream side of the third stage rotor blade 630 . ..

The fourth flasher 214 and the low pressure economizer 103 are connected by a condensed water discharge line 155. The condensed water discharge line 155 is connected to the first heated water line 111 and indirectly connected to the low pressure economizer 103. The condensed water discharge line 155 is provided with a condensed water discharge pump 155a.

Next, the operation of the combined cycle plant 1 of the present embodiment will be described.

The compressor 11 of the gas turbine 10 compresses the air A and supplies the compressed air A to the combustor 20. Fuel is also supplied to the combustor 20. In the combustor 20, fuel is burned in the compressed air A to generate high-temperature and high-pressure combustion gas. This combustion gas is sent from the combustor 20 to the combustion gas flow path in the turbine 30, and rotates the gas turbine rotor 13. The rotation of the gas turbine rotor 13 causes the first generator 15 connected to the gas turbine 10 to generate electricity.

The combustion gas obtained by rotating the gas turbine rotor 13 is exhausted from the turbine 30 as exhaust gas, and is discharged to the atmosphere from the chimney 129 via the exhaust heat recovery boiler 100 and the flue 128. The exhaust heat recovery boiler 100 recovers the heat contained in the exhaust gas in the process of passing the exhaust gas from the turbine 30.

Water is supplied to the low-temperature heat exchanger 102 on the most downstream side (chimney 129 side) of the exhaust heat recovery boiler 100 via the water supply line 71. In this water supply, the steam exhausted from the steam outlet of the low-pressure steam turbine 603 is turned into water by the condenser 240. The low temperature heat exchanger 102 heats the water supply by exchanging heat between the water supply and the exhaust gas. The water supply heated by the low temperature heat exchanger 102 is sent to the low pressure economizer 103 via the first heated water line 111. In the low-pressure economizer 103, heat is exchanged between the water supply and the exhaust gas to generate low-pressure heated water in which the water supply is further heated. The pressure of the low pressure heated water is kept higher than the drum pressure of the low pressure evaporator 104 in order to prevent boiling from occurring in the low pressure economizer 103. A part of the low-pressure heating water generated by the low-pressure economizer 103 is depressurized by the first evaporator water supply valve 112a provided in the second heating water line 112 and sent to the low-pressure evaporator 104.

The low-pressure evaporator 104 heats the low-pressure heated water by exchanging heat between the low-pressure heated water and the exhaust gas to generate low-pressure steam. The generated low-pressure steam is sent to the low-pressure superheater 105 via the first steam line 121.

The low-pressure superheater 105 exchanges heat between the low-pressure steam and the exhaust gas to superheat the low-pressure steam to generate low-pressure superheated steam. The generated low-pressure superheated steam is sent from the low-pressure steam line 135 to the steam inlet of the low-pressure steam turbine 603 via the medium-pressure exhaust line 134.

Further, a part of the low-pressure heated water heated by the low-pressure economizer 103 flows into the third heated water line 113. The low-pressure heating water flowing into the third heating water line 113 is boosted by the high-pressure pump 115 to become high-pressure heating water. This high-pressure heating water is sent to the high-pressure economizer 107 via the third heating water line 113.

In the high-pressure economizer 107, the high-pressure heated water is further heated by exchanging heat between the high-pressure heated water and the exhaust gas. The high-pressure heated water heated by the high-pressure economizer 107 is sent to the high-pressure evaporator 108 via the fourth heating water line 114. The pressure of the heated high-pressure heated water is kept higher than the drum pressure of the high-pressure evaporator 108 in order to prevent boiling from occurring in the high-pressure economizer 107. The high-pressure heated water heated by the high-pressure economizer 107 is depressurized by the second evaporator water supply valve 114a provided in the fourth heating water line 114, and is sent to the high-pressure evaporator 108.

The high-pressure evaporator 108 heats the high-pressure heated water by exchanging heat between the high-pressure heated water heated by the high-pressure economizer 107 and the exhaust gas, and generates high-pressure steam. The generated high-pressure steam is sent to the high-pressure superheater 109 via the second steam line 122.

The high-pressure superheater 109 exchanges heat between the high-pressure steam and the exhaust gas to superheat the high-pressure steam to generate high-pressure superheated steam. The generated high-pressure superheated steam is sent to the steam inlet of the high-pressure steam turbine 601 via the high-pressure steam line 131.

As a result, the high-pressure steam turbine 601 is driven using the high-pressure superheated steam as the main steam. Both the pressure and the temperature of the high-pressure superheated steam decrease in the process of flowing through the high-pressure steam turbine 601. The high-pressure superheated steam exhausted from the high-pressure steam turbine 601 flows into the medium-pressure reheater 106 via the high-pressure exhaust line 132.

In the medium pressure reheater 106, the high pressure superheated steam whose pressure and temperature have decreased is reheated by the exhaust gas. As a result, medium-pressure superheated steam having a lower pressure than the high-pressure superheated steam generated by the high-pressure superheater 109 is generated. Here, the temperature of the generated medium-pressure superheated steam (reheated steam) is equal to or higher than that of the high-pressure superheated steam. This is because the pressure of the medium-pressure superheated steam is lower than that of the high-pressure steam, and due to the limitation of the durability of equipment such as pipes and heat transfer tubes, raising the temperature of the medium-pressure superheated steam raises the temperature of the high-pressure heated steam. Because it's easier than doing. Further, since the medium pressure reheater 106 is located upstream of the high pressure superheater 109 when viewed from the distribution direction of the exhaust gas, the temperature of the medium pressure superheated steam can be made equal to or higher than that of the high pressure superheated steam. can.

The medium-pressure superheated steam is sent to the steam inlet of the medium-pressure steam turbine 602 via the medium-pressure steam line 133. As a result, the medium pressure steam turbine 602 is driven using the medium pressure superheated steam as the main steam. In the process of flowing through the medium pressure steam turbine 602, both the pressure and the temperature of the medium pressure superheated steam decrease to the same level as the low pressure superheated steam. The medium-pressure superheated steam exhausted from the medium-pressure steam turbine 602, that is, the medium-pressure exhaust steam is sent to the steam inlet of the low-pressure steam turbine 603 via the medium-pressure exhaust line 134.

Further, a part of the low-pressure heated water heated by the low-pressure economizer 103 flows from the second heating water line 112 into the first flasher water supply line 141. The low-pressure heated water flowing into the first flasher water supply line 141 is sent to the first flasher 211 via the first flasher water supply valve 141a. In the first flasher 211, first saturated steam having a pressure equivalent to that of low-pressure superheated steam is generated. The first saturated steam flows into the medium pressure exhaust line 134 via the first saturated steam line 151. Therefore, the medium-pressure exhaust steam exhausted from the medium-pressure steam turbine 602, the low-pressure superheated steam sent from the low-pressure superheater 105, and the first saturated steam flow into the steam inlet of the low-pressure steam turbine 603. The low-pressure steam turbine 603 is driven by using the steam obtained by mixing these steams as the main steam. At the inlet of the low pressure steam turbine 603, the main steam is in an overheated state.

Further, the first condensed water generated by generating the first saturated steam flows from the first flasher 211 into the second flasher water supply line 142. The first condensed water flowing into the second flasher water supply line 142 is sent to the second flasher 212 via the second flasher water supply valve 142a. In the second flasher 212, the second saturated steam is generated. The second saturated steam is supplied to the second stage of the low pressure steam turbine 603 via the second saturated steam line 152. In the low-pressure steam turbine 603, the main steam flowing in the vicinity of the second stage of the main flow path C and the second saturated steam are mixed.

The second condensed water generated by generating the second saturated steam flows from the second flasher 212 into the third flasher water supply line 143. The second condensed water flowing into the third flasher water supply line 143 is sent to the third flasher 213 via the third flasher water supply valve 143a. In the third flasher 213, the third saturated steam is generated. The third saturated steam is supplied to the third stage of the low pressure steam turbine 603 via the third saturated steam line 153. In the low-pressure steam turbine 603, the main steam flowing in the vicinity of the third stage of the main flow path C and the third saturated steam are mixed.

The third condensed water generated by generating the third saturated steam flows from the third flasher 213 to the fourth flasher water supply line 144. The third condensed water flowing into the fourth flasher water supply line 144 is sent to the fourth flasher 214 via the fourth flasher water supply valve 144a. In the fourth flasher 214, the fourth saturated steam is generated. The fourth saturated steam is supplied to the wet region C1 near the final stage of the low-pressure steam turbine 603 via the fourth saturated steam line 154. In the low-pressure steam turbine 603, the main steam flowing through the wet region C1 of the main flow path C and the fourth saturated steam are mixed.

The fourth condensed water generated by generating the fourth saturated steam flows into the condensed water discharge line 155 from the fourth flasher 214. The fourth condensed water that has flowed into the condensed water discharge line 155 flows into the first heated water line 111 via the condensed water discharge pump 155a. As a result, the fourth condensed water is sent to the low-pressure economizer 103 together with the water supplied by the low-temperature heat exchanger 102.

The main steam exhausted from the steam outlet of the low-pressure steam turbine 603 flows into the condenser 240 via the low-pressure exhaust line 136. In the condenser 240, this steam is cooled and condensed to become water. This water passes through the water supply line 71 and is sent to the low temperature heat exchanger 102 again as water supply.

According to the combined cycle plant 1 provided with the steam turbine system 200 as described above, the fourth saturated steam is supplied from the fourth flasher 214 to the wet region C1 of the main flow path C of the low pressure steam turbine 603. By sending the fourth saturated steam to the wet region C1, the fourth saturated steam is mixed with the main steam in the wet region C1. In the wet region C1, the dryness decreases and the main steam becomes wet steam, but when the fourth saturated steam is mixed, the dryness of the main steam increases and the amount of heat (enthalpy) increases. As a result, it is possible to suppress the generation of drain in the wet region C1 and the downstream region of the wet region C1. As a result, it is possible to suppress the occurrence of erosion in the moving blades 630 arranged in the wet region C1 and the moving blades 630 located downstream of the wet region C1.

Further, in the present embodiment, in order to effectively recover and utilize the heat having a temperature corresponding to the saturation temperature at each pressure, the first saturated steam, the second saturated steam, and the second saturated steam having a pressure higher than that of the fourth saturated steam are used. The third saturated steam is supplied to the overheated region of the main steam in the region upstream of the wet region C1. When the saturated steam is supplied to the upstream region of the wet region C1, that is, the superheated region where the main steam is superheated steam, the calorific value (enthalpy) of the saturated steam is lower than the calorific value (enthalpi) of the superheated steam. At each location where air-fuel mixture is performed, the calorific value (enthalpy) of the main steam decreases, and the dryness also decreases in the downstream wet region C1. As a result, it causes erosion and a decrease in efficiency of the steam turbine. However, in the present embodiment, the increase in the dryness in the wet region C1 due to the air-fuel mixture of the fourth saturated steam is the dryness in the wet region C1 due to the air-fuel mixture of the first saturated steam, the second saturated steam, and the third saturated steam. It is possible to offset the decrease in erosion and suppress the generation of erosion and the decrease in efficiency of the low-pressure steam turbine.

Further, each of the first saturated steam, the second saturated steam, the third saturated steam, and the fourth saturated steam has a saturation temperature equal to the pressure of the main steam at the position where the steam is charged. Therefore, by being supplied to the main flow path C of the low-pressure steam turbine 603, it is possible to further suppress the decrease in efficiency of the low-pressure steam turbine 603.

Further, the saturated steam generation unit 210 of the present embodiment is a multi-stage that generates flash steam a plurality of times while gradually reducing the pressure in the order of the first flasher 211, the second flasher 212, the third flasher 213, and the fourth flasher 214. Has a flasher. Therefore, it is possible to generate a plurality of saturated vapors having different pressures. As a result, saturated steam having different pressures and temperatures can be sent to the low pressure steam turbine 603. Therefore, saturated steam corresponding to the pressure of the main steam flowing through the main flow path C can be supplied to the low pressure steam turbine 603. The first saturated steam having a relatively high pressure is generated from the high-temperature low-pressure heated water, and the saturated steam having a lower pressure than the first saturated steam is generated from the remaining condensed water having a lower temperature. In this way, by sequentially generating saturated steam while lowering the pressure and temperature, saturated steam with the highest possible pressure and temperature can be obtained and supplied to the steam turbine, effectively outputting the steam turbine. The efficiency of the system can be increased. Further, by generating flash steam multiple times while lowering the pressure, the supplied water can be used until the temperature becomes low. Therefore, the heat of water when generating saturated steam can be recovered to a low temperature, the output of the steam turbine can be increased, and the efficiency of the system can be improved.

Further, a part of the low-pressure heated water generated by the low-pressure economizer 103 of the exhaust heat recovery boiler 100 is supplied to the first flasher 211 via the first flasher water supply line 141. Therefore, the first saturated steam can be obtained by using the high-temperature low-pressure heated water heated by the exhaust gas in the exhaust heat recovery boiler 100. Further, the second saturated steam can be obtained by utilizing the first condensed water generated after the first saturated steam is generated. Similarly, a third saturated steam and a fourth saturated steam can also be obtained. Further, since saturated steam can be obtained over a plurality of steps from high-temperature low-pressure heated water, it is possible to easily generate saturated steam corresponding to different pressures and temperatures.

Further, among the exhaust heat recovery boilers 100, the low-pressure heated water generated by the low-pressure economizer 103 is supplied to the first flasher 211. Therefore, after the heat of the exhaust gas of the gas turbine 10 is sufficiently recovered by the exhaust heat recovery boiler 100, high-temperature water can be further obtained by utilizing the heat of the exhaust gas.

Further, if the temperature of the exhaust gas supplied to the low pressure evaporator 104 becomes close to the temperature of the low pressure heated water supplied to the low pressure evaporator 104, the heat of the exhaust gas is recovered in the exhaust heat recovery boiler 100. Even if it is not sufficient, the low temperature exhaust heat can be recovered further. Specifically, the low-pressure superheated water generated by the low-pressure coal saver 103 is generated as saturated steam a plurality of times by the saturated steam generation unit 210 and supplied to the low-pressure steam turbine 603 as an output of the low-pressure steam turbine 603. The heat of the exhaust gas is recovered. Therefore, the heat contained in the exhaust gas can be used more effectively.

Further, the fourth condensed water generated by generating the fourth saturated steam with the fourth flasher 214 is sent to the first heated water line 111 via the condensed water discharge line 155. As a result, the fourth condensed water is sent to the low-pressure economizer 103 together with the water supplied heated by the low-temperature heat exchanger 102. Therefore, it is possible to prevent the fourth condensed water from being directly returned to the low temperature heat exchanger 102 that heats the supply water by using the heat of the exhaust gas having the lowest temperature, and the temperature of the supply water from rising. Therefore, the amount of heat recovered in the low temperature heat exchanger 102 can be increased as compared with the case where the fourth condensed water is returned to the low temperature heat exchanger 102. In particular, when the temperature of the supply water supplied to the low temperature heat exchanger 102 is lower than the dew point temperature of the exhaust gas as in the present embodiment, the low temperature heat exchanger 102 partially condenses the water content in the exhaust gas. , The amount of heat recovered in the low temperature heat exchanger 102 can be further increased.

<< Second Embodiment >>
Next, a second embodiment of the combined cycle plant of the present invention will be described with reference to FIG. The combined cycle plant 1A shown in the second embodiment is different from the first embodiment in that, for example, it is further provided with a feed water heater 78 for heating water supply and is not provided with a low temperature heat exchanger 102. Therefore, in the description of the second embodiment, the same parts as those of the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 2, the combined cycle plant 1A of the second embodiment includes an intake air cooler 40, a cooling air cooler (gas turbine cooler) 50, a first generator cooler 16, and first lubrication. An oil cooler 17, a second generator cooler 66, and a second lubricating oil cooler 67 are provided.

The intake air cooler 40 exchanges heat between the first cooling medium that cools the air A sucked by the compressor 11 and the water supply to cool the first cooling medium and heat the water supply. The intake air cooler 40 includes an intake air heat exchanger 41 and an intake air refrigerator 42. The intake heat exchanger 41 heats the first cooling medium while cooling the air A by exchanging heat between the air A sucked by the compressor 11 and the first cooling medium. The intake refrigerator 42 transfers the heat of the first cooling medium heated by the intake heat exchanger 41 to the supply water to heat the supply water while cooling the first cooling medium.

The cooling air cooler 50 exchanges heat between the second cooling medium that cools the components of the gas turbine 10 and the water supply to cool the second cooling medium and heat the water supply. The cooling air cooler 50 cools the air in order to cool the high-temperature component in contact with the high-temperature combustion gas among the components constituting the gas turbine 10. Therefore, the second cooling medium in the cooling air cooler 50 is air such as compressed air and bleed air. Among the parts constituting the gas turbine 10, the high-temperature parts that come into contact with the high-temperature combustion gas include the tail tube of the combustor 20, the stationary blade and the moving blade of the turbine 30. The cooling air cooler 50 includes a first air cooler 51, a second air cooler 52, and a third air cooler 53.

The first air cooler 51 cools the compressed air compressed by the compressor 11 to generate combustor cooling air for cooling the parts of the combustor 20 such as the tail tube. The first air cooler 51 sends the generated combustor cooling air to the combustor 20.

The second air cooler 52 cools the compressed air compressed by the compressor 11 to generate, for example, pre-stage cooling air for cooling the stationary blade and the moving blade of the front stage of the turbine 30. The second air cooler 52 sends the generated pre-stage cooling air to the front stage of the turbine 30.

The third air cooler 53 cools the bleed air extracted from the middle stage of the compressor 11 to generate, for example, post-stage cooling air for cooling the stationary blade and the moving blade of the rear stage of the turbine 30. The third air cooler 53 sends the generated post-stage cooling air to the rear stage of the turbine 30.

The first generator cooler 16 exchanges heat between the third cooling medium that cools the components of the first generator 15 and the water supply to cool the third cooling medium and heat the water supply. The first generator cooler 16 cools the rotor and the stator of the first generator 15 with a third cooling medium such as hydrogen. The first generator cooler 16 is provided in the first generator 15. The first generator cooler 16 cools the cooling medium by heat exchange with the water supply.

The first lubricating oil cooler 17 exchanges heat between the lubricating oil from the first bearing 14 and the water supply to cool the lubricating oil and heat the supply water to return the cooled lubricating oil to the first bearing 14. .. The first lubricating oil cooler 17 cools the lubricating oil by exchanging heat between the lubricating oil from the first bearing 14 and the water supply. The first lubricating oil cooler 17 returns the cooled lubricating oil to the first bearing 14.

The second generator cooler 66 exchanges heat between the third cooling medium that cools the components of the second generator 230 and the water supply to cool the third cooling medium and heat the water supply. Similar to the first generator cooler 16, the second generator cooler 66 cools the rotor and the stator of the second generator 230 with a third cooling medium such as hydrogen. The second generator cooler 66 is provided in the second generator 230. The second generator cooler 66 cools the cooling medium by heat exchange with the water supply.

The second lubricating oil cooler 67 exchanges heat between the lubricating oil from the second bearing 220 and the water supply to cool the lubricating oil and heat the supply water, and returns the cooled lubricating oil to the second bearing 220. .. The second lubricating oil cooler 67 cools the lubricating oil by exchanging heat between the lubricating oil from the second bearing 220 and the water supply. The second lubricating oil cooler 67 returns the cooled lubricating oil to the second bearing 220.

Further, the water supply system 70A of the second embodiment includes a water supply line 71A, a water supply pump 79, and a feed water heater 78 for heating the feed water flowing through the water supply line 71A.

The water supply line 71A of the second embodiment has a first water supply line 72, a second water supply line 73, a third water supply line 74, and a fourth water supply line 75.

The first water supply line 72 connects the condenser 240 and the low-pressure economizer 103 of the exhaust heat recovery boiler 100. A water supply pump 79 is provided in the first water supply line 72. In the first water supply line 72, on the downstream side of the water supply flow from the water supply pump 79, there are an intake refrigerator 42, a subcooler 77, a first generator cooler 16, a first lubricating oil cooler 17, and a third air cooler. 53 and the second air cooler 52 are provided in this order.

Therefore, in the intake refrigerator 42, the heat of the cooling medium heated by heat exchange with the air A sucked by the compressor 11 is transferred to the water supply flowing through the first water supply line 72. As a result, the water supply is heated while the cooling medium is cooled. Further, the subcooler 77 cools the water supply heated by the intake refrigerator 42. Further, in the first generator cooler 16, the water supply cooled by the subcooler 77 and the cooling medium for cooling the first generator 15 are heat-exchanged to cool the cooling medium and heat the water supply. Further, in the first lubricating oil cooler 17, the water supply heated by the first generator cooler 16 and the lubricating oil from the first bearing 14 are heat-exchanged to cool the lubricating oil while heating the water supply. do. Further, in the third air cooler 53, the water supplied heated by the first lubricating oil cooler 17 and the bleed air extracted from the middle stage of the compressor 11 are heat-exchanged, and the bleed air is cooled while being cooled. The water supply is heated. Further, in the second air cooler 52, the water supply heated by the third air cooler 53 and the compressed air compressed by the compressor 11 are heat-exchanged, and the compressed air is cooled while the water supply is heated. Will be done.

The second water supply line 73 branches from the first water supply line 72 between the intake refrigerator 42 and the subcooler 77. The second water supply line 73 is connected to the low pressure exhaust line 136. Therefore, the second water supply line 73 returns a part of the water supply heated by the intake refrigerator 42 to the condenser 240 again.

The third water supply line 74 branches from the first water supply line 72 between the third air cooler 53 and the second air cooler 52. The third water supply line 74 rejoins the first water supply line 72 on the downstream side of the water supply flow from the position where the second air cooler 52 is arranged in the first water supply line 72. The third water supply line 74 is provided with a first air cooler 51. Therefore, in the first air cooler 51, the water supply flowing through the third water supply line 74 and the compressed air compressed by the compressor 11 are heat-exchanged, and the compressed air is cooled while the water supply is heated.

The fourth water supply line 75 branches from the first water supply line 72 between the subcooler 77 and the first generator cooler 16. The fourth water supply line 75 joins the third water supply line 74 between the first lubricating oil cooler 17 and the third air cooler 53. The fourth water supply line 75 is provided with a second generator cooler 66 and a second lubricating oil cooler 67. Therefore, in the second generator cooler 66, the water supply flowing through the fourth water supply line 75 and the cooling medium for cooling the second generator 230 are heat-exchanged to cool the cooling medium and heat the water supply. Further, in the second lubricating oil cooler 67, the water supplied heated by the second generator cooler 66 and the lubricating oil from the second bearing 220 are heat-exchanged to cool the lubricating oil while heating the water supply. do.

The feed water heater 78 heats the water supply which is the water flowing through the water supply line 71A. The feed water heater 78 is provided in the feed water line 71A. The water supply heater 78 of the present embodiment includes an intake air cooler 40, a first generator cooler 16, a first lubricating oil cooler 17, a second generator cooler 66, and a second lubricating oil cooler 67. And the cooling air cooler 50.

The water supply heater 78 includes an intake air cooler 40, a first generator cooler 16, a first lubricating oil cooler 17, a second generator cooler 66, a second lubricating oil cooler 67, and the like. The configuration is not limited to the configuration including all of the cooling air cooler 50, and at least one of them may be included.

Further, the second saturated steam line 152 of the second embodiment is connected so as to communicate with the main flow path C on the upstream side of the second stage rotor blade 630 and on the downstream side of the second stage stationary blade 650. Has been done. That is, the second saturated steam line 152 communicates with the main flow path C on the upstream side of the second-stage stationary blade 650 as in the first embodiment, and the second- stage stationary blade as in the second embodiment. It is not limited to communicating with the main flow path C on the downstream side of the 650 . The second saturated steam line 152 may be connected so as to communicate with the main flow path C on the upstream side or the downstream side of the stationary blade 650 near the second stage.

Further, the third saturated steam line 153 of the second embodiment is connected so as to communicate with the main flow path C on the upstream side of the third stage rotor blade 630 and on the downstream side of the third stage stationary blade 650. Has been done. That is, the third saturated steam line 153 communicates with the main flow path C on the upstream side of the third-stage stationary blade 650 as in the first embodiment, and the third- stage stationary blade as in the second embodiment. It is not limited to communicating with the main flow path C on the downstream side of the 650 . The third saturated steam line 153 may be connected so as to communicate with the main flow path C on the upstream side or the downstream side of the stationary blade 650 near the third stage.

Further, the fourth saturated steam line 154 of the second embodiment is connected so as to communicate with the main flow path C on the upstream side of the fourth stage rotor blade 630 and on the downstream side of the fourth stage stationary blade 650. Has been done. That is, the fourth saturated steam line 154 communicates with the main flow path C on the upstream side of the fourth-stage stationary blade 650 as in the first embodiment, and the fourth- stage stationary blade as in the second embodiment. It is not limited to communicating with the main flow path C on the downstream side of the 650 . The fourth saturated steam line 154 may be connected upstream of the stationary blade 650 of the wet region C1 so as to communicate with the main flow path C in the wet region C1.

Next, the operation of the combined cycle plant 1A of the second embodiment will be described. Similarly to the first embodiment, the main steam exhausted from the low pressure steam turbine 603 flows into the condenser 240. In the condenser 240, the main steam is cooled and condensed to become water. The water generated by the condenser 240 is pumped to the water supply line 71A by the water supply pump 79 as water supply. The feed water flowing through the feed water line 71A is heated by the feed water heater 78 in the process of flowing through the feed water line 71A. Specifically, this water supply includes an intake air cooler 40, a first generator cooler 16, a first lubricating oil cooler 17, a second generator cooler 66, a second lubricating oil cooler 67, and a first air cooling. It is heated by the vessel 51, the second air cooler 52, and the third air cooler 53.

First, the water supply from the condenser 240 flows through the first water supply line 72 and flows into the intake refrigerator 42. When the temperature of the air A sucked by the compressor 11 becomes high, the mass flow rate of the air A sucked by the compressor 11 decreases. Therefore, when the temperature of the air A sucked by the compressor 11 becomes high, the gas turbine output decreases. Therefore, in the present embodiment, the intake air cooler 40 transfers the heat of the air A sucked by the compressor 11 to the water supply, and cools the air A while heating the water supply.

A part of the water supply heated by the intake air cooler 40 flows into the second water supply line 73. The water supply that has flowed into the second water supply line 73 is sent to the condenser 240 again via the low pressure exhaust line 136.

Further, a part of the water supply heated by the intake air cooler 40 further flows through the first water supply line 72 and is sent to the subcooler 77. The water supply sent to the subcooler 77 is cooled and sent to the first generator cooler 16. The water supply sent to the first generator cooler 16 transfers the heat of the third cooling medium to the water supply, heats the water supply, and cools the third cooling medium.

The water supply heated by the first generator cooler 16 is sent to the first lubricating oil cooler 17. The water supply sent to the first lubricating oil cooler 17 transfers the heat of the lubricating oil to the water supply to heat the water supply while cooling the lubricating oil.

A part of the water supply heated by the first lubricating oil cooler 17 further flows through the first water supply line 72 and is sent to the third air cooler 53. The water supply sent to the third air cooler 53 transfers the heat of the bleed air to the water supply, heating the water supply and cooling the bleed air.

The water supply heated by the third air cooler 53 is sent to the second air cooler 52. The water supply sent to the second air cooler 52 transfers the heat of the compressed air to the water supply, heating the water supply and cooling the compressed air. The water supply heated by the second air cooler 52 further flows through the first water supply line 72, merges with the fourth condensed water, and is sent to the low-pressure economizer 103.

Further, a part of the water supply cooled by the subcooler 77 flows into the fourth water supply line 75. The water supply that has flowed into the fourth water supply line 75 is sent to the second generator cooler 66. The water supply sent to the second generator cooler 66 transfers the heat of the third cooling medium to the water supply, heats the water supply, and cools the third cooling medium.

The water supply heated by the second generator cooler 66 is sent to the second lubricating oil cooler 67. The water supply sent to the second lubricating oil cooler 67 transfers the heat of the lubricating oil to the supply water, heats the supply water, and cools the lubricating oil. The water supply heated by the second generator cooler 66 and the second lubricating oil cooler 67 is rejoined to the first water supply line 72 to be combined with the water supplied by the first lubricating oil cooler 17. After merging, it is sent to the third air cooler 53.

Further, a part of the water supply heated by the third air cooler 53 is sent to the first air cooler 51 via the third water supply line 74. The water supply sent to the first air cooler 51 transfers the heat of the compressed air to the water supply, heating the water supply and cooling the compressed air. The water supply heated by the first air cooler 51 is merged with the water supply heated by the second air cooler 52 by rejoining the first water supply line 72, and then merges with the fourth condensed water. And sent to the low pressure economizer 103.

According to the combined cycle plant 1A provided with the steam turbine system 200 as described above, the heat obtained by cooling the air A sucked by the compressor 11 and the configuration of the gas turbine 10 as the heat source for heating the water supply by the water supply heater 78. The heat obtained by cooling the compressed air and the extracted air for cooling the parts, the heat obtained by cooling the lubricating oil, and the heat obtained by cooling the turbine can be effectively used. Therefore, in the second embodiment, the waste heat obtained by cooling these cooling targets can be effectively used, and the efficiency of the combined cycle plant 1A can be improved.

Further, in the second embodiment, the fourth condensed water is merged with the water supply whose temperature has risen by cooling all of these cooling targets. Therefore, the water supply to which the fourth condensed water is previously merged is supplied to the intake air cooler 40, the cooling air cooler 50, the first generator cooler 16, the first lubricating oil cooler 17, the second generator cooler 66, and the like. The temperature of the supply water used for cooling can be kept low and the amount of heat exchange in each cooler can be increased as compared with the case where the water is sent to the second lubricating oil cooler 67. Therefore, it is possible to suppress a decrease in cooling efficiency in each device, improve reliability, increase the amount of waste heat recovered during cooling, and increase the output of the steam turbine and the efficiency of the system.

<< Third Embodiment >>
Next, a third embodiment of the combined cycle plant of the present invention will be described with reference to FIG. The combined cycle plant 1B shown in the third embodiment is different from the first embodiment and the second embodiment in the position where the saturated steam is supplied in the wet region C1. Therefore, in the description of the third embodiment, the same parts as those of the first embodiment and the second embodiment are described with the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 3, in the steam turbine system 200B of the combined cycle plant 1B of the third embodiment, the saturated steam generator 210B produces the fourth saturated steam from between the stationary blade 650 and the moving blade 630 in the wet region C1. We are supplying. Specifically, the low-pressure steam turbine 603B of the third embodiment has a saturated steam introduction unit 69. The saturated steam introduction unit 69 communicates the fourth saturated steam line 154 with the main flow path C. The saturated steam introduction section 69 is provided so as to penetrate the steam turbine casing 64B. The saturated steam introduction section 69 is open between the rotor blade 630 and the stationary blade 650 in the final stage near the tip 631 side of the rotor blade 630. As a result, the saturated steam generation unit 210B of the third embodiment is formed by the fourth flasher 214 in the main flow path C from the upstream side of the rotor blade 630 in the final stage of the low-pressure steam turbine 603B toward the tip 631 of the rotor blade 630. It supplies the generated fourth saturated steam.

According to the combined cycle plant 1B provided with the steam turbine system 200B as described above, the fourth saturated steam generated by the fourth flasher 214 flows into the saturated steam introduction unit 69 via the fourth saturated steam line 154. The fourth saturated steam flowing into the saturated steam introduction section 69 is supplied to the wet region C1 from the opening of the steam turbine casing 64B facing the main flow path C. In the wet region C1, the fourth saturated steam is supplied from the downstream side of the immediately preceding stationary blade 650 arranged on the upstream side of the rotor blade 630 in the final stage to the vicinity of the tip 631 of the rotor blade 630. As a result, the fourth saturated steam is mainly supplied to the rotor blade 630, which is particularly susceptible to erosion, in the wet region C1. Further, since the saturated steam introduction portion 69 is opened near the tip 631 side of the moving blade 630 of the steam turbine casing 64B, the fourth saturated steam is generated near the tip 631 which is particularly susceptible to erosion among the moving blades 630. Many are supplied. Therefore, in the rotor blade 630, it is possible to suppress the generation of drain at the tip 631 where erosion is particularly likely to occur.

<< Fourth Embodiment >>
Next, a fourth embodiment of the combined cycle plant of the present invention will be described with reference to FIGS. 4 and 5. In the combined cycle plant 1C shown in the fourth embodiment, the position where the saturated steam is supplied in the wet region C1 is different from that of the first embodiment to the third embodiment. Therefore, in the description of the fourth embodiment, the same parts as those of the first to third embodiments are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 4, in the combined cycle plant 1C of the fourth embodiment, the saturated steam generation unit 210C is formed in the hollow portion 651 formed inside the stationary blade 650C arranged in the wet region C1 of the low pressure steam turbine 603C. Supply the fourth saturated steam. Specifically, the low-pressure steam turbine 603C of the fourth embodiment has a saturated steam introduction unit 69C. The saturated steam introduction unit 69C communicates the fourth saturated steam line 154 with the hollow portion 651. The saturated steam introduction section 69C is provided so as to penetrate the steam turbine casing 64C .

The stationary blade 650C of the fourth embodiment has a hollow portion 651 and a plurality of supply ports 652.
As shown in FIG. 5, the hollow portion 651 is a through hole formed inside the stationary blade 650C.
The hollow portion 651 extends from the inner peripheral side (rotor shaft 62 side) of the stationary blade 650C in the blade height direction to the outer peripheral side (steam turbine casing 64C side). The hollow portion 651 is formed at a position close to the leading edge portion 653 in the airfoil cross section. The opening on the outer peripheral side of the hollow portion 651 is connected to the saturated steam introduction portion 69C. The hollow portion 651 of the present embodiment is formed only inside the stationary blade 650C arranged in the final stage, which is the wet region C1.

A plurality of supply ports 652 are formed in the leading edge portion 653 of the stationary blade 650C so as to communicate the hollow portion 651 and the main flow path C. The supply port 652 discharges the fourth saturated steam supplied into the hollow portion 651 to the main flow path C. A plurality of supply ports 652 (three in this embodiment) are formed on the leading edge portion 653 in the airfoil cross section. Further, as shown in FIG. 4, a plurality of supply ports 652 are formed apart from each other in the blade height direction (seven rows in the present embodiment). The plurality of supply ports 652 are formed so that the amount of the fourth saturated steam released increases from the inner peripheral side to the outer peripheral side in the blade height direction. Specifically, the hole diameters of the plurality of supply ports 652 increase from the inner peripheral side to the outer peripheral side in the blade height direction. Further, the plurality of supply ports 652 are arranged so that the distance in the blade height direction becomes narrower from the inner peripheral side to the outer peripheral side in the blade height direction.

According to the combined cycle plant 1C provided with the steam turbine system 200C as described above, the fourth saturated steam generated by the fourth flasher 214 flows into the saturated steam introduction section 69C via the fourth saturated steam line 154. The fourth saturated steam that has flowed into the saturated steam introduction section 69C flows into the hollow section 651. The fourth saturated steam flowing into the hollow portion 651 flows from the outer peripheral side to the inner peripheral side in the hollow portion 651, and is discharged from the plurality of supply ports 652 to the wet region C1. The fourth saturated steam released from the supply port 652 flows toward the downstream side after being discharged toward the upstream side from the leading edge portion 653 of the stationary blade 650C. The amount of the fourth saturated steam released from the supply port 652 increases from the inner peripheral side in the blade height direction toward the outer peripheral side. Therefore, the amount of the fourth saturated steam flowing through the wet region C1 is larger on the outer peripheral side than on the inner peripheral side in the blade height direction. As a result, the fourth saturated steam is mainly supplied to the tip 631 of the rotor blade 630, which is particularly susceptible to erosion, in the wet region C1. Therefore, in the rotor blade 630, it is possible to suppress the generation of drain at the tip 631 where erosion is particularly likely to occur.

<< Fifth Embodiment >>
Next, a fifth embodiment of the combined cycle plant of the present invention will be described with reference to FIG. In the combined cycle plant 1D shown in the fifth embodiment, the configuration of the saturated steam generation unit 210D is different from that of the first embodiment to the fourth embodiment. Therefore, in the description of the fifth embodiment, the same parts as those of the first to fourth embodiments are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 6, in the steam turbine system 200D of the combined cycle plant 1D of the fifth embodiment, the supply source of the saturated steam supplied to the wet region C1 is another device other than the multi-stage flasher. The combined cycle plant 1D further includes a low temperature low pressure economizer 301 and a low temperature low pressure evaporator 302.

The low temperature low pressure economizer 301 is arranged between the low temperature heat exchanger 102 and the chimney 129. A water supply line 71D is connected to the low-temperature low-pressure economizer 301, and water is supplied from the condenser 240.

Exhaust gas that has passed through the low-temperature low-pressure evaporator 302 flows into the low-temperature low-pressure economizer 301. The low-temperature low-pressure economizer 301 exchanges heat between the exhaust gas passing through the flue 128 and the water supply, and heats the water supply to generate low-temperature low-pressure heated water. The low-temperature low-pressure heating water has a lower temperature and a lower pressure than the low-pressure heating water produced by the low-pressure economizer 103. The low-temperature low-pressure economizer 301 sends the generated low-temperature low-pressure superheated water to the low-temperature low-pressure evaporator 302 and the low-temperature heat exchanger 102. The low-temperature low-pressure economizer 301 and the low-temperature low-pressure evaporator 302 are connected by a low-temperature low-pressure heated water line 303. Further, the low-temperature low-temperature economizer 301 and the low-temperature heat exchanger 102 are connected by a water supply branch line 305. The water supply branch line 305 is provided with a branch line pump 305a for boosting. Exhaust gas that has passed through the low-temperature low-pressure economizer 301 is released into the atmosphere from the chimney 129.

A part of the low-temperature low-pressure heated water flows into the low-temperature low-pressure evaporator 302. Exhaust gas that has passed through the low-temperature heat exchanger 102 flows into the low-temperature low-pressure evaporator 302. The low-temperature low-pressure evaporator 302 exchanges heat between the low-temperature low-pressure heated water and the exhaust gas. The low-temperature low-pressure evaporator 302 heats low-temperature low-pressure heated water to generate low-temperature low-pressure saturated steam. The low-temperature low-pressure saturated steam is a low-pressure saturated steam having a saturation temperature at a pressure equivalent to that of the main steam in the wet region C1, similarly to the fourth saturated steam. The low-temperature low-pressure evaporator 302 sends the generated low-temperature low-pressure saturated steam to the wet region C1 of the low-temperature steam turbine 603.

The low-temperature low-pressure evaporator 302 and the low-pressure steam turbine 603 are connected by a low-temperature low-pressure saturated steam line 304. The low-temperature low-pressure saturated steam line 304 is connected so as to communicate with the main flow path C of the low-pressure steam turbine 603 near the final stage.

Further, a part of the low-temperature low-pressure heated water is boosted by the branch line pump 305a and flows into the low-temperature heat exchanger 102. The low-temperature heat exchanger 102 heats the exhaust gas passing through the flue 128 and the pressurized low-temperature low-pressure heated water to heat the low-temperature low-pressure heated water while cooling the exhaust gas.

The saturated steam generator 210D of the fifth embodiment is composed of a first flasher 211, a second flasher 212, a third flasher 213D, and a low temperature low pressure evaporator 302. Therefore, the multi-stage flasher used in the fifth embodiment has three stages and does not have the fourth flasher 214.

The third flasher 213D of the fifth embodiment supplies the third condensed water, which is condensed water generated by flushing the water, to the low pressure economizer 103. Therefore, the condensed water discharge line 155D of the fifth embodiment connects the third flasher 213D and the low pressure economizer 103. The condensed water discharge line 155D is connected to the first heated water line 111. The condensed water discharge line 155D is provided with a condensed water discharge pump 155a.

Even in the combined cycle plant 1D equipped with the steam turbine system 200D as described above, the dryness of the main steam in the wet region C1 can be increased. As a result, it is possible to suppress the generation of drain on the side downstream of the wet region C1 and the wet region C1. As a result, it is possible to suppress the occurrence of erosion in the moving blades 630 arranged on the downstream side of the wet region C1 and the wet region C1.

<< Sixth Embodiment >>
Next, the sixth embodiment of the combined cycle plant of the present invention will be described with reference to FIG. 7. In the combined cycle plant 1E shown in the sixth embodiment, the configuration of the saturated steam generation unit 210E is different from that of the first embodiment to the fifth embodiment. Therefore, in the description of the sixth embodiment, the same parts as those of the first to fifth embodiments are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 7, in the steam turbine system 200E of the combined cycle plant 1E of the sixth embodiment, the source of the saturated steam supplied to the wet region C1 is not a multi-stage flasher, as in the fifth embodiment. It is a device. Low-pressure steam is supplied to the wet region C1 as saturated steam from the low-pressure evaporator 104E. Therefore, the saturated steam generation unit 210E of the sixth embodiment is composed of the first flasher 211, the second flasher 212, the third flasher 213, and the low pressure evaporator 104E. Therefore, the saturated steam generation unit 210E of the sixth embodiment also does not have the fourth flasher 214 as in the third embodiment.

The low-pressure evaporator 104E of the sixth embodiment sends a part of the generated low-pressure steam as low-pressure saturated steam to the wet region C1 of the low-pressure steam turbine 603. The low pressure evaporator 104E and the low pressure steam turbine 603 are connected by a low pressure saturated steam line 401. The low pressure saturated steam line 401 is connected to the first steam line 121. The low- pressure saturated steam line 401 is connected so as to communicate with the main flow path C of the low-pressure steam turbine 603 near the final stage.

Even in the combined cycle plant 1E equipped with the steam turbine system 200E as described above, the dryness of the main steam in the wet region C1 can be increased. As a result, it is possible to suppress the generation of drain on the side downstream of the wet region C1 and the wet region C1. As a result, it is possible to suppress the occurrence of erosion in the moving blades 630 arranged on the downstream side of the wet region C1 and the wet region C1.

Further, unlike the fifth embodiment, the low temperature low pressure economizer 301 and the low temperature low pressure evaporator 302 are not required, so that the saturated steam can be supplied to the wet region C1 with a simpler equipment than the fifth embodiment. can.

<< Seventh Embodiment >>
Next, a seventh embodiment of the combined cycle plant of the present invention will be described with reference to FIG. In the combined cycle plant 1F shown in the seventh embodiment, the configuration of the saturated steam generation unit 210F is different from that of the first embodiment to the sixth embodiment. Therefore, in the description of the seventh embodiment, the same parts as those of the first to sixth embodiments are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 8, in the steam turbine system 200F of the combined cycle plant 1F of the seventh embodiment, the exhaust heat of the gas turbine 10 can be further recovered by the multi-stage flasher of the saturated steam generation unit 210F. Specifically, the saturated steam generation unit 210F of the seventh embodiment recovers the exhaust heat from the bleed air cooler 80 that cools the bleed air extracted from the intermediate stage of the compressor 11.

The combined cycle plant 1F of the seventh embodiment has an bleed air cooler 80 that cools the bleed air extracted from the compressor 11 and then sends it to the turbine 30 to cool the components of the turbine 30. The bleed air cooler 80 has a first bleed air cooler 81, a second bleed air cooler 82, and a third bleed air cooler 83.

The first bleed air cooler 81 cools the bleed air extracted from the rear stage of the compressor 11 to generate, for example, pre-stage cooling air for cooling the stationary blade and the moving blade of the front stage of the turbine 30. The first bleed air cooler 81 sends the generated pre-stage cooling air to the front stage of the turbine 30.

The second bleed air cooler 82 draws air from the compressor 11 on the upstream side of the first bleed air cooler 81. The second bleed air cooler 82 sends the bleed air cooled to the turbine 30 on the downstream side of the first bleed air cooler 81. Therefore, the second bleed air cooler 82 cools the bleed air extracted from the middle stage of the compressor 11, for example, to generate the middle stage cooling air for cooling the stationary blade and the moving blade in the middle stage of the turbine 30. The second bleed air cooler 82 sends the generated middle stage cooling air to the middle stage of the turbine 30.

The third bleed air cooler 83 draws air from the compressor 11 on the upstream side of the second bleed air cooler 82. The third bleed air cooler 83 sends the bleed air cooled to the turbine 30 on the downstream side of the second bleed air cooler 82. Therefore, the third bleed air cooler 83 cools the bleed air extracted from the front stage of the compressor 11, for example, to generate the post-stage cooling air for cooling the stationary blade and the moving blade of the rear stage of the turbine 30. The third bleed air cooler 83 sends the generated post-stage cooling air to the rear stage of the turbine 30.

Further, the first flasher 211 of the seventh embodiment sends a part of the first condensed water to the second flasher water supply line 142 and also to the first condensed water return line 161. The first condensed water return line 161 heats the first condensed water and then sends it to the first flasher water supply line 141. The first condensed water return line 161 connects the first flasher 211 and the first flasher water supply line 141. The first condensed water return line 161 is connected to the first flasher water supply line 141 on the upstream side of the first flasher water supply valve 141a. The first condensed water return line 161 is provided with a first condensed water feed pump 171. The first condensed water feed pump 171 is a boosting means for boosting the first condensed water generated by the first flasher 211. The first condensed water return line 161 is provided with a first bleed air cooler 81 on the downstream side of the first condensed water feed pump 171. In the first bleed air cooler 81, the first condensed water pumped through the first condensed water return line 161 by the first condensed water feed pump 171 and the bleed air extracted from the subsequent stage of the compressor 11 are heat exchanged. , The bleed air is cooled and the first condensed water is heated. Therefore, the first bleed air cooler 81 also serves as a heat source for heating the first condensed water.

The third flasher 213 of the seventh embodiment sends a part of the third condensed water to the fourth flasher water supply line 144 and also to the third condensed water return line 163. The third condensed water return line 163 heats the third condensed water and then sends it to the third flasher water supply line 143. The third condensed water return line 163 connects the third flasher 213 and the third flasher water supply line 143. The third condensed water return line 163 is connected to the third flasher water supply line 143 on the upstream side of the third flasher water supply valve 143a. The third condensed water return line 163 is provided with a third condensed water feed pump 173. The third condensed water feed pump 173 is a boosting means for boosting the third condensed water generated by the third flasher 213. The third condensed water return line 163 is provided with a second bleed air cooler 82 on the downstream side of the third condensed water feed pump 173. Therefore, in the second bleed air cooler 82, the third condensed water pumped through the third condensed water return line 163 by the third condensed water feed pump 173 and the bleed air extracted from the middle stage of the compressor 11 heat. It is replaced, the bleed air is cooled and the third condensed water is heated. Therefore, the second bleed air cooler 82 also serves as a heat source for heating the third condensed water.

The fourth flasher 214 of the seventh embodiment sends a part of the fourth condensed water to the condensed water discharge line 155 and also to the fourth condensed water return line 164. The fourth condensed water return line 164 heats the fourth condensed water and then sends it to the fourth flasher water supply line 144. The fourth condensed water return line 164 connects the fourth flasher 214 and the fourth flasher water supply line 144. The fourth condensed water return line 164 is connected to the fourth flasher water supply line 144 on the upstream side of the fourth flasher water supply valve 144a. The fourth condensed water return line 164 is provided with a fourth condensed water feed pump 174. The fourth condensed water feed pump 174 is a boosting means for boosting the fourth condensed water generated by the fourth flasher 214. The fourth condensed water return line 164 is provided with a third bleed air cooler 83 on the downstream side of the fourth condensed water feed pump. Therefore, in the third bleed air cooler 83, the fourth condensed water pumped through the fourth condensed water return line 164 by the fourth condensed water feed pump 174 and the bleed air extracted from the front stage of the compressor 11 heat. It is replaced, the bleed air is cooled and the fourth condensed water is heated. Therefore, the third bleed air cooler 83 also serves as a heat source for heating the fourth condensed water.

According to the combined cycle plant 1F provided with the steam turbine system 200F as described above, the first condensed water is heated by the first bleed air cooler 81 by utilizing the heat of the bleed air from the compressor 11. By mixing the heated first condensed water with the low-pressure heating water flowing through the first flasher water supply line 141 , the flow rate of the low-pressure heating water supplied to the first flasher 211 increases, and the temperature rises. Similarly, in the second bleed air cooler 82 and the third bleed air cooler 83, the third condensed water and the fourth condensed water are heated by using the heat of the extracted air from the compressor 11 and returned to the upstream. , The flow rate of water supplied to the third flasher 213 and the fourth flasher 214 increases, and the temperature rises. As a result, the waste heat from the first bleed air cooler 81, the second bleed air cooler 82, and the third bleed air cooler 83 can be effectively used, and the efficiency of the combined cycle plant 1F can be improved.

(Other variants of the embodiment)
Although the embodiments of the present invention have been described in detail with reference to the drawings, the configurations and combinations thereof in each embodiment are examples, and the configurations may be added or omitted within a range not deviating from the gist of the present invention. , Replacements, and other changes are possible. Further, the present invention is not limited to the embodiments, but only to the scope of claims.

Therefore, the configuration of the embodiment of the present invention is not limited to any one of the first embodiment to the seventh embodiment, such as combining the configuration of the first embodiment and the configuration of the second embodiment. not.

Further, the saturated steam generation unit is limited to a configuration in which the flash steam generated by the flasher is supplied as saturated steam or a configuration in which the saturated steam is supplied by using the exhaust heat recovery boiler 100 as in the present embodiment. is not. The saturated steam generation unit 210 may have a configuration capable of sending saturated steam to the wet region C1.

Further, the saturated steam generation unit is not limited to a configuration capable of supplying a plurality of saturated steams having different conditions as in the multi-stage flasher of the present embodiment. The saturated steam generation unit may be configured to generate only saturated steam to be sent to the wet region C1.

Further, the exhaust heat recovery boiler 100 is not limited to the configuration of the present embodiment. Therefore, the exhaust heat recovery boiler 100 may further have other economizers, evaporators, superheaters, reheaters, and conversely, some economizers, evaporators, and the like. It is not necessary to have a superheater or a reheater.

1, 1A, 1B, 1C, 1D, 1E, 1F Combined Cycle Plant 10 Gas Turbine 11 Compressor
13 Gas turbine rotor
14 First bearing
15 First generator
16 First generator cooler
17 First lubricating oil cooler
20 Combustor 30 Turbine
40 Intake cooler
41 Intake heat exchanger
42 Intake refrigerator
50 Cooling air cooler
51 First air cooler
52 Second air cooler
53 Third air cooler
60 steam turbine
61 Steam turbine rotor
62 Rotor shaft
63 Blade row
64, 64B, 64C steam turbine casing
65 Static wing row
66 Second generator cooler
67 Second lubricating oil cooler
69, 69C Saturated steam introduction section
70, 70A Water supply system
71, 71A, 71D water supply line
72 First water supply line
73 Second water supply line
74 Third water supply line
75 Fourth water supply line
77 subcooler
78 Feed water heater
79 Water supply pump
80 Bleed air cooler
81 First bleed air cooler
82 Second bleed air cooler
83 Third bleed air cooler
100 Exhaust heat recovery boiler 101 Boiler outer frame 102 Low temperature heat exchanger 103 Low pressure economizer 104, 104E Low pressure evaporator 105 Low pressure superheater 106 Medium pressure reheater 107 High pressure economizer 108 High pressure evaporator 109 High pressure superheater 111 1 Heating water line 112 2nd heating water line 113 3rd heating water line
114 Fourth heating water line
115 High pressure pump 121 1st steam line 122 2nd steam line
128 flue
129 chimney
131 High pressure steam line
132 High pressure exhaust line
133 Medium pressure steam line
134 Medium pressure exhaust line
135 low pressure steam line
136 low pressure exhaust line
141 First flasher water supply line
141a First flasher water supply valve
142 Second flasher water supply line
142a Second flasher water supply valve
143 Third flasher water supply line
143a Third flasher water supply valve
144 Fourth Flasher Water Supply Line
144a Fourth flasher water supply valve
151 First saturated steam line
152 Second saturated steam line
153 Third saturated steam line
154 Fourth saturated steam line
155, 155D condensed water discharge line
155a Condensed water discharge pump
161 First condensed water return line
163 Third condensed water return line
164 Fourth condensed water return line
171 First condensed water feed pump
173 Third condensed water feed pump
174 Fourth Condensed Water Feed Pump
200, 200B, 200C, 200D, 200E, 200F steam turbine system
210, 210B, 210C, 210D, 210E, 210F Saturated steam generator
211 First Flasher
212 Second Flasher
213, 213D Third flasher
214 Fourth Flasher
220 Second bearing
230 second generator
240 condenser
301 Low temperature low pressure economizer
302 low temperature low pressure evaporator
303 Low temperature low pressure heating water line
304 Low temperature low pressure saturated steam line
305 Water supply branch line
305a branch line pump
401 Low pressure saturated steam line
601 High pressure steam turbine 602 Medium pressure steam turbine 603, 603B, 603C Low pressure steam turbine 630 Moving blade
631 tip
650 Static wing 650C Static wing 651 Hollow part 652 Supply port 653 Leading edge part
A air
C main flow path
C1 wet area

Claims (8)

A steam turbine with a main flow path through which main steam flows inside,
A saturated steam generator that generates saturated steam,
An exhaust heat recovery boiler that generates steam with the heat of exhaust gas,
A water supply system that supplies water to the waste heat recovery boiler,
Equipped with
The steam turbine drives the steam generated in the exhaust heat recovery boiler as the main steam.
The saturated steam generation unit generates flash steam by flushing the water generated in the exhaust heat recovery boiler as the saturated steam.
The condensed water generated by flushing the water is heated by a heat source other than the exhaust gas, and the water is heated.
An exhaust heat recovery plant in which the saturated steam is sent to the steam turbine, and
With a gas turbine
Equipped with
The exhaust gas of the gas turbine is supplied to the exhaust heat recovery boiler of the exhaust heat recovery plant.
The exhaust heat recovery boiler generates steam by the heat of the exhaust gas of the gas turbine, and the exhaust heat recovery boiler generates steam.
A combined cycle plant in which the heat obtained by cooling the compressed air or the extracted air that cools the components of the gas turbine is used as a heat source other than the exhaust gas. A steam turbine with a main flow path through which main steam flows inside,
A saturated steam generator that generates saturated steam,
An exhaust heat recovery boiler that generates steam with the heat of exhaust gas,
A water supply system that supplies water to the waste heat recovery boiler,
The heat exchanger provided in the water supply system and
Equipped with
The steam turbine drives the steam generated in the exhaust heat recovery boiler as the main steam.
The saturated steam generation unit generates flash steam by flushing the water generated in the exhaust heat recovery boiler as the saturated steam.
The heat exchanger heats the water supplied from the water supply system to the exhaust heat recovery boiler with a heat source other than the exhaust gas, and then sends the water to the exhaust heat recovery boiler.
The exhaust heat recovery boiler heats the water received from the heat exchanger by exchanging heat with the exhaust gas, and sends a part of the water to the saturated steam generation unit as water generated by the exhaust heat recovery boiler. ,
As the heat exchanger
A generator cooler that cools the cooling medium and heats the water by exchanging heat between the water and the cooling medium that cools the components of the generator that generates electricity by driving the steam turbine or other device.
A lubricating oil cooler that cools the lubricating oil and heats the water by exchanging heat between the lubricating oil from the bearing that rotatably supports the steam turbine or other device and the water.
Equipped with
The generator cooler and the lubricating oil cooler are exhaust heat recovery plants provided in the order of the generator cooler and the lubricating oil cooler along the flow of water in the water supply system . A steam turbine with a main flow path through which main steam flows inside,
A saturated steam generator that generates saturated steam,
An exhaust heat recovery boiler that generates steam with the heat of exhaust gas,
A water supply system that supplies water to the waste heat recovery boiler,
The heat exchanger provided in the water supply system and
Equipped with
The steam turbine drives the steam generated in the exhaust heat recovery boiler as the main steam.
The saturated steam generation unit generates flash steam by flushing the water generated in the exhaust heat recovery boiler as the saturated steam.
The heat exchanger heats the water with a heat source other than the exhaust gas, and then sends the water to the exhaust heat recovery boiler.
The exhaust heat recovery boiler heats the water received from the heat exchanger by exchanging heat with the exhaust gas, and sends a part of the water to the saturated steam generation unit as water generated by the exhaust heat recovery boiler. Heat recovery plant and
With a gas turbine
Equipped with
The exhaust gas of the gas turbine is supplied to the exhaust heat recovery boiler of the exhaust heat recovery plant.
The exhaust heat recovery boiler generates steam by the heat of the exhaust gas of the gas turbine, and the exhaust heat recovery boiler generates steam.
As the heat exchanger
An intake air cooler that cools the first cooling medium and heats the water by exchanging heat between the first cooling medium that cools the air sucked by the gas turbine and the water.
A cooling air cooler that cools the second cooling medium and heats the water by exchanging heat between the second cooling medium that cools the components of the gas turbine and the water.
A generator that cools the third cooling medium and heats the water by exchanging heat between the water and the third cooling medium that cools the components of the generator that generates power by driving the steam turbine or the gas turbine. With a cooler,
A lubricating oil cooler that cools the lubricating oil and heats the water by exchanging heat between the lubricating oil from the bearing that rotatably supports the steam turbine or the gas turbine and the water.
Of these, with two or more types,
These two or more types of the heat exchangers are the intake cooler, the generator cooler, the lubricating oil cooler, and the cooling air cooler in this order along the flow of water in the water supply system. Combined cycle plant provided. A steam turbine with a main flow path through which main steam flows inside,
A saturated steam generator that generates saturated steam,
An exhaust heat recovery boiler that generates steam with the heat of exhaust gas,
A water supply system that supplies water to the waste heat recovery boiler,
Equipped with
The steam turbine drives the steam generated in the exhaust heat recovery boiler as the main steam.
The saturated steam generation unit generates flash steam by flushing the water generated in the exhaust heat recovery boiler as the saturated steam.
Further equipped with a feed water heater that heats the water flowing through the water supply system with a heat source other than the exhaust gas.
The saturated steam generator sends condensed water generated by flushing the water generated in the exhaust heat recovery boiler to the water supply system.
The water supply system sends the condensed water to the exhaust heat recovery boiler together with the water after being heated by the feed water heater.
The feed water heater cools the medium and heats the water by exchanging heat with a medium other than the exhaust gas as a heat source.
The condensed water is an exhaust heat recovery plant that joins the water heated by the feed water heater in the water supply system . A steam turbine with a main flow path through which main steam flows inside,
A saturated steam generator that generates saturated steam,
An exhaust heat recovery boiler that generates steam with the heat of exhaust gas,
A water supply system that supplies water to the waste heat recovery boiler,
Equipped with
The steam turbine drives the steam generated in the exhaust heat recovery boiler as the main steam.
The saturated steam generation unit generates flash steam by flushing the water generated in the exhaust heat recovery boiler as the saturated steam.
At least one of the water flowing through the water supply system and the condensed water generated by flushing the water is heated by a heat source other than the exhaust gas.
The saturated steam is sent to the steam turbine and
The exhaust heat recovery boiler is
A low-temperature heat exchanger that heats the exhaust gas and the water to heat the water and cool the exhaust gas.
An economizer that produces low-pressure heated water by exchanging heat between the exhaust gas, the condensed water, and the water heated by the low-temperature heat exchanger.
An evaporator that heats the low-pressure heated water and cools the exhaust gas by exchanging heat between the exhaust gas and the low-pressure heated water.
Have,
The low-temperature heat exchanger, the economizer, and the evaporator are arranged in the order of the low-temperature heat exchanger, the economizer, and the evaporator from the downstream side to the upstream side of the exhaust gas flow.
A part of the low-pressure heated water is an exhaust heat recovery plant that is sent to the saturated steam generation unit as the water generated in the exhaust heat recovery boiler. The exhaust heat recovery plant according to claim 5, wherein the water supply system supplies the water having a temperature lower than the dew point temperature of the exhaust gas introduced into the low temperature heat exchanger to the low temperature heat exchanger. The exhaust heat recovery plant according to claim 6, wherein the low temperature heat exchanger increases the amount of heat recovered from the exhaust gas by condensing the water in the exhaust gas. A waste heat recovery plant according to any one of claims 5 to 7 and a gas turbine are provided.
The exhaust gas of the gas turbine is supplied to the exhaust heat recovery boiler of the exhaust heat recovery plant.
The exhaust heat recovery boiler is a combined cycle plant that generates steam by the heat of the exhaust gas of the gas turbine.

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