JP4452328B2 - Combined power plant - Google Patents

Description

  The present invention relates to a combined power plant in which a generator is rotated by a steam turbine and a gas turbine.

  A combined power plant in which a generator is rotated by a steam turbine and a gas turbine uses the Brayton cycle of a gas turbine that uses combustion gas as a working fluid as a high-temperature cycle, and the exhaust gas is used as the working fluid from water vapor on the low-temperature side. By using it as a heating fluid for the Rankine cycle, the operating temperature of the combined cycle heat engine is increased and the combined thermal efficiency is improved.

  In a combined power generation plant in which a generator is rotated by a conventional steam turbine and gas turbine, for example, as shown in FIG. 6, steam for driving the steam turbine is generated by the exhaust heat recovery boiler 100. The exhaust heat recovery boiler 100 includes an economizer (heating economizer) 101 that heats feed water, an evaporator 102 that generates steam from the feed water heated by the economizer 101, and a superheater 103 that superheats the generated steam. The superheated steam is generated using the exhaust gas of the gas turbine that rotates the machine. The superheated steam supplied from the exhaust heat recovery boiler 100 is sent to the steam turbine, and the generator is also rotationally driven by the steam turbine.

  The water supply system for supplying water to the above-described exhaust heat recovery boiler 100 includes, for example, a hot well tank 110, a deaerator 112, and a water supply pump 113. The makeup water is injected into the hot well tank 110 through the deaerator 112. The water supplied through the hot well tank 110 is pressurized by the water supply pump 113, passes through the economizer 101 of the above-described exhaust heat recovery boiler 100, and is heated by the exhaust gas of the gas turbine as described above. In addition, steam process return water is injected into the hot well tank 110 through the deaerator 114, and steam turbine condensate is also injected.

  On the other hand, the steam for driving the steam turbine needs to maintain the dissolved oxygen amount below a certain value from the viewpoint of preventing corrosion of the boiler 100 and the steam turbine. However, conventionally, pure water generated from hard water through a dehydrator is often used as makeup water (see, for example, Non-Patent Documents 1 and 2). ) Can dissolve a high concentration of oxygen of about 10 mg / L. Further, the space 111 above the liquid surface of the hot well tank 110 is open to the atmosphere, and oxygen dissolution from the inflowing air also occurs in the hot well tank 110.

Therefore, in the conventional combined power plant, the makeup water is injected into the hot well tank 110 after passing through the deaerator 112 and, for example, between the economizer 101 and the evaporator 102 and, if necessary, the hot well tank 110. A large amount of oxygen scavenger is introduced between the water supply pump 113 and the water supply pump 113. In addition, when operating with a variable thermoelectric type, the return water of the steam process may also have high concentration of oxygen dissolved therein, and is injected into the hot well tank 110 after passing through the deaerator 114. .
Akira Nozaki, “Composite power generation system for aeroderivative gas turbine”, Journal of the Gas Turbine Society of Japan (Vol. 27, No. 3), Gas Turbine Society of Japan, May 20, 1999, p. 32 (Fig. 5) Koji Konishi, three others, “Osaka Gas Power Generation Facilities for Power Business”, Journal of the Gas Turbine Society of Japan (Vol. 31, No. 4), Japan Gas Turbine Society, July 20, 2003, p. 16 (Fig. 3)

  As described above, in the conventional combined power plant, oxygen having a high concentration is dissolved in the makeup water. Therefore, a deaerator has to be disposed in the makeup water line, and a large amount of oxygen removal is performed. The agent must be charged. Therefore, the conventional combined power plant has a problem that it is extremely expensive in terms of equipment cost, energy loss, maintenance cost, and operation cost. In particular, in the case of the thermoelectric variable type, a deaerator is also required for the return water of the steam process, resulting in a further increase in equipment costs, and it is practically difficult to realize a variable thermoelectric combined power plant. .

  The present invention has been made to solve such problems, and greatly reduces the amount of oxygen scavenger used in a combined power plant, and eliminates the need for installing a deaerator, thereby reducing equipment costs, It is an object of the present invention to provide a combined power generation plant that can achieve significant cost reduction in energy loss, maintenance cost, and operation cost.

  In order to solve the above-mentioned problem, the means employed by the present invention is a combined power generation plant in which a generator is rotated by a steam turbine and a gas turbine, and the combined power generation plant uses steam exhaust gas to generate steam. An exhaust heat recovery boiler that generates superheated steam for rotating the turbine and has an economizer, and a hot well tank that temporarily stores water to be supplied to the economizer, the hot well tank has a predetermined amount of water to store There is a heating means for heating to a temperature, and the heating means is to use water supply heated by an economizer as a heat source.

  Thus, by providing the hot well tank with heating means for heating the stored water to a predetermined temperature, the amount of dissolved oxygen in the stored water can be greatly reduced. This eliminates the need to install a deaerator for make-up water and return water from the steam process, which is required in conventional combined power plants, and significantly reduces the use of oxygen scavengers in the water supply. Can be made. Furthermore, when the heating means uses the water supply heated by the economizer as a heat source, a self-contained system is formed, and a water supply system that makes more effective use of the exhaust heat of the gas turbine can be constructed.

  Further, the means employed by the present invention is a combined power generation plant in which a generator is rotated by a steam turbine and a gas turbine, and the combined power generation plant is configured to rotate the steam turbine by exhaust gas from the gas turbine. An exhaust heat recovery boiler that generates superheated steam and has an economizer, and a hot well tank that stores water to be supplied to the economizer. The hot well tank has steam at a predetermined pressure in the space above the surface of the water to be stored. The steam is to be generated using water supply heated by an economizer.

  In this way, by filling the space above the liquid level of the hot well tank with steam at a predetermined pressure, it is possible to prevent the outside air from entering the hot well tank and prevent the water supply from coming into contact with the outside air. Thereby, it is possible to reliably prevent the dissolution of oxygen in the water supply stored in the hot well tank. This eliminates the need to install a deaerator for make-up water and return water from the steam process, which is required in conventional combined power plants, and significantly reduces the use of oxygen scavengers in the water supply. Can be made. Furthermore, by generating steam using the water supply heated by the economizer, a self-contained system can be formed, and a water supply system that can effectively use the exhaust heat of the gas turbine can be constructed.

  Furthermore, the means adopted by the present invention is a combined power plant that rotates a generator by a steam turbine and a gas turbine, and the combined power plant is an overheater that rotates the steam turbine by exhaust gas of the gas turbine. A waste heat recovery boiler that generates steam and has an economizer, and a hot well tank that stores water to be supplied to the economizer, the hot well tank has heating means for heating the water to be stored to a predetermined temperature. The space above the liquid level of the feed water to be stored and filled is filled with steam at a predetermined pressure. .

  Thus, by providing the hot well tank with heating means for heating the stored water to a predetermined temperature, the amount of dissolved oxygen in the stored water can be greatly reduced. At the same time, by filling the space above the liquid level of the hot well tank with steam at a predetermined pressure, it is possible to prevent the outside air from entering the hot well tank and prevent the water supply from coming into contact with the outside air. Thus, it is possible to reliably prevent the dissolution of oxygen in the water supply stored in the hot well tank. For this reason, the installation of a deaerator for make-up water and the return water of the steam process, which is required in conventional combined power plants, can be made more reliable, and oxygen scavengers can be added to the feed water. Input can be further reduced significantly.

  The apparatus further comprises temperature detection means for detecting the temperature of the feed water in the hot well tank, and first flow rate control means for supplying the feed water heated by the economizer to the heating means. Based on the temperature of the feed water detected by the detection means, it is desirable to supply the feed water heated by the economizer to the heating means. Thereby, the water supply temperature in the hot well tank can be automatically adjusted to the predetermined temperature.

  The predetermined temperature is desirably 50 ° C. or higher and 85 ° C. or lower. This is because when the feed water temperature in the hot well tank is less than 50 ° C., the amount of dissolved oxygen in the feed water is not sufficiently reduced, making it unnecessary to install a deaerator for make-up water and return water from the steam process. This is because there is a possibility that it is not possible to reduce the amount of oxygen scavenger added to the water supply. If the water supply temperature in the hot well tank exceeds 85 ° C, the amount of dissolved oxygen will decrease further, while the amount of water supplied to the hot well tank will increase and energy loss may occur. is there. The predetermined temperature is more preferably 55 ° C or higher and 70 ° C or lower.

  It is desirable to include second flow rate control means for supplying the water supply heated by the economizer by controlling the flow rate into the space above the liquid level of the hot well tank. By supplying the feed water heated by the economizer into the space above the liquid level, the feed water is immediately flushed and vaporized by sudden pressure reduction. Thereby, the space above the liquid level of the hot well tank can be filled with steam. Further, the vapor pressure in the space above the liquid level can be maintained at the predetermined pressure by the second flow rate control means.

  The second flow rate control means includes a barometer for detecting the atmospheric pressure in the space above the liquid level of the hot well tank, a first flow rate control valve for supplying water supply by controlling the flow rate into the space above the liquid level, and the atmospheric pressure. It is desirable to provide a controller that controls the operation of the first flow control valve based on the atmospheric pressure detected by the meter. By configuring the second flow rate control means in this way, the vapor pressure in the space above the liquid level in the hot well tank can be automatically adjusted to the predetermined pressure.

  The hot well tank has a vent portion that allows the space above the liquid level to communicate with the atmosphere, and the second flow rate control means supplies the water supplied by the economizer by controlling the flow rate into the space above the liquid level. It is desirable to provide a flow rate control valve and a check valve that is disposed in the vent portion and prohibits the backflow of the atmosphere into the space above the liquid level. By configuring the second flow rate control means in this way, the space above the liquid level of the hot well tank can be easily filled with the steam having the predetermined pressure.

  The predetermined pressure is preferably from 0.1 kPA to 50 kPA. This is because when the predetermined pressure is less than 0.1 kPA, it is not possible to sufficiently prevent the outside air from entering the hot well tank. For this reason, the amount of dissolved oxygen in the feed water stored in the hot well tank cannot be significantly reduced, and the installation of a deaerator for make-up water or the return water of the steam process cannot be made unnecessary. There is a possibility that the input of the oxygen scavenger to the water supply cannot be significantly reduced. If the predetermined pressure exceeds 50 kPA, the amount of water supplied to the hot well tank will increase, resulting in energy loss and the problem of pressure resistance of the hot well tank itself. is there. The predetermined pressure is more preferably 1 kPA or more and 5 kPA or less.

  As described above in detail, the combined power generation plant of the present invention is a combined power generation plant in which a generator is rotated by a steam turbine and a gas turbine, and the combined power generation plant uses a gas turbine exhaust gas to generate a steam turbine. An exhaust heat recovery boiler having an economizer and a hot well tank for storing water to be supplied to the economizer, and the hot well tank is configured to keep the water to be stored at a predetermined temperature. Heating means for heating is provided, and the heating means uses water supplied by the economizer as a heat source.

  The combined power plant of the present invention is a combined power plant that rotates a generator by a steam turbine and a gas turbine, and the combined power plant rotates the steam turbine by the exhaust gas of the gas turbine. An exhaust heat recovery boiler that generates superheated steam and has an economizer, and a hot well tank that stores water to be supplied to the economizer. The hot well tank has steam at a predetermined pressure in the space above the surface of the water to be stored. The steam is generated using water supply heated by an economizer.

  Therefore, the combined power plant of the present invention greatly reduces the amount of oxygen scavenger used in the combined power plant and eliminates the need for installing a deaerator, thereby reducing the equipment cost, energy loss, maintenance cost, and operation. It has an excellent effect that the cost can be greatly reduced.

  A first best mode for carrying out the combined power plant of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a schematic diagram showing a first best mode for carrying out the combined power plant of the present invention, FIG. 2 is a schematic diagram showing a power generation system of the combined power plant, and FIG. 3 is another power generation system. FIG. 4 is a graph showing the solubility of oxygen in pure water.

  As shown in FIGS. 1 and 2, this power generation system is a combined power generation plant in which a generator 50 is rotationally driven by a steam turbine 30 and a gas turbine 40, and a Brayton cycle of the gas turbine 40 using combustion gas as a working fluid. Used in a cycle on the high temperature side, and its exhaust gas is used as a heating fluid for the Rankine cycle using steam on the low temperature side as the working fluid, thereby increasing the operating temperature of the combined cycle heat engine and improving the combined thermal efficiency It is.

  As shown in FIG. 1, the feed water and steam generation system of the combined power generation plant includes a hot well tank 1, an exhaust heat recovery boiler 20, and the like. The hot well tank 1 is connected with a makeup water supply line 10, a process return water supply line 11, and a steam turbine condensate supply line 12 described later. Pure water or soft water is supplied into the hot well tank 1 from the makeup water supply line 10 and the process return water supply line 11. Further, pure water as condensate is supplied from the steam turbine condensate supply line 12 into the hot well tank 1.

  In the hot well tank 1, a heat exchanger (heating means) 2 is disposed. On the other hand, the exhaust heat recovery boiler 20 includes an economizer 21 for heating the feed water, an evaporator 22 for generating steam from the heated feed water, and a super heater 23 for superheating the generated steam. The water supply stored in the hot well tank 1 is pressurized by the water supply pump 14 and sent to the economizer 21. Most of the water supplied from the exhaust gas discharged from the gas turbine 40 by the economizer 21 is sent to the steam drum 24.

  The feed water sent to the evaporator 22 through the steam drum 24 is heated by the exhaust gas discharged from the gas turbine 40 to become steam, and is returned to the steam drum 24 again. In the steam drum 24, a part of the feed water containing impurities and the like is blown and discharged out of the system. Only the steam that is sent from the steam drum 24 to the brackish water separator 25 and separated by the brackish water separator 25 is sent to the superheater 23. A part of the steam superheated by the superheater 23 is sent to the steam turbine 30 described above, and the steam turbine 30 is rotationally driven. Further, the remaining superheated steam is cooled through the temperature reducer 27 and then sent to the steam process.

  A part of the water supply heated by the exhaust gas discharged from the gas turbine 40 by the economizer 21 is sent to the heat exchanger 2 in the hot well tank 1, and the heat exchanger 2 stores the water in the hot well tank 1. The feed water exchanged with the feed water is drained into the hot well tank 1 through the temperature control valve (first flow rate control means) 16. A water supply thermometer (temperature detection means) 15 is disposed between the hot well tank 1 and the above-described water supply pump 14, and the water supply temperature at the outlet of the hot well tank 1 is detected by the water supply thermometer 15. The feed water temperature at the outlet of the hot well tank 1 is substantially the same as the feed water temperature in the hot well tank 1. The feed water temperature detected by the feed water thermometer 15 is input to a controller (first flow rate control means) (not shown), and the controller opens the temperature control valve 16 based on the feed water temperature detected by the feed water thermometer 15. To control.

  Another part of the water supply heated by the exhaust gas discharged from the gas turbine 40 by the economizer 21 is supplied to the hot well tank 1 via the high-temperature water shut-off valve (first flow control valve) 18. It is supplied to the liquid surface upper space 3. The hot well tank 1 is provided with an in-tank pressure gauge (barometer) 17 for detecting the atmospheric pressure in the hot well tank 1. The atmospheric pressure in the hot well tank 1 detected by the in-tank pressure gauge 17 is input to a controller (not shown), and the controller uses high-temperature water based on the vapor pressure in the hot well tank 1 detected by the in-tank pressure gauge 17. The opening degree of the shut-off valve 18 is controlled. In the upper part of the hot well tank 1, a vent part 4 is provided for allowing the vapor in the hot well tank 1 to escape to the atmosphere. Note that the first flow rate control valve can be configured by a general-purpose flow rate control valve instead of the high-temperature water cutoff valve 18.

  As shown in FIG. 2, the steam turbine 30 is rotationally driven by the superheated steam supplied from the above-described exhaust heat recovery boiler 20, and its rotation shaft is connected to the generator 50 via the governor 31. Then, the generator 50 is driven to rotate. The steam adiabatically expanded by the steam turbine 30 and the temperature thereof is lowered is sent to the condenser 32. The condenser 32 has a role of lowering the back pressure of the steam turbine 30 according to the condenser internal pressure and collecting the condensate. For this reason, the steam that has flowed into the condenser 32 is cooled by the external cooling water to become condensate in an extremely low pressure state by the vacuum pump 33. The condensate generated in the condenser 32 flows into the hot well tank 1 shown in FIG.

  The gas turbine 40 includes a compressor 41, a combustor 42, and a turbine 43. The atmosphere compressed by the compressor 41 is sent to the combustor 42, while the fuel gas compressed by the gas compressor 46 driven by the motor 45 is injected into the combustor 42 and burned. The combustion gas is adiabatically expanded in the turbine 43 and rotationally drives the turbine 43, and then flows into the exhaust heat recovery boiler 20 shown in FIG. The turbine 43 has a rotating shaft connected to the generator 50 via the speed governor 44 and drives the generator 50 to rotate.

  In addition, as shown in FIG. 3, the separate power generators 51 and 52 are each connected with the steam turbine 30 and the gas turbine 40, and the combined power generation plant of this invention can also be formed.

  Next, the operation of the combined power plant of the present invention will be described.

  As shown in FIG. 1, pure water or soft water as make-up water and process return water, and pure water as steam turbine condensate are supplied to a hot well tank 1, and water for a combined power plant is supplied to the hot well. The water is once stored in the tank 1. The controller controls the opening degree of the temperature control valve 16 based on the feed water temperature detected by the feed water thermometer 15, and a part of the feed water heated by the exhaust gas discharged from the turbine 43 of the gas turbine 40 by the economizer 21. Is supplied to the heat exchanger 2 in the hot well tank 1 so that the feed water temperature is in the range of 50 ° C. to 85 ° C., for example, 60 ° C. (predetermined temperature).

  As described above, about 5 mg / L oxygen in terms of atmospheric pressure is dissolved in the water supply in the hot well tank 1 adjusted to 60 ° C. as shown in FIG. Thus, by adjusting the water supply temperature in the hot well tank 1 to, for example, 60 ° C., the amount of dissolved oxygen at room temperature can be reduced to about half compared to about 10 mg / L. . The water supply in the hot well tank 1 may include soft water as make-up water and process return water. FIG. 4 shows the solubility of oxygen in pure water at atmospheric pressure. When soft water is contained in the water supply, the dissolved oxygen amount is in the pure water due to the relationship with substances other than dissolved oxygen. It may be slightly different. However, the reduction ratio of the dissolved oxygen amount by the combined power plant of the present invention compared to the conventional combined power plant can be considered to be almost the same as that of pure water.

  This eliminates the need for a deaerator for make-up water and steam process return water, which is required in conventional combined power plant water supply systems. Input can be greatly reduced. For this reason, significant cost reduction can be achieved in equipment cost, energy loss, maintenance cost, and operation cost.

  Further, as the means for heating the water supply in the hot well tank 1, the heat exchanger 2 using the water supply heated by the economizer 21 as a heat source is used, so that a self-contained system is formed, and the exhaust heat of the gas turbine 40 is formed. It is possible to construct a water supply system that makes more effective use of water. The feed water temperature in the hot well tank 1 is desirably 50 ° C. or more and 85 ° C. or less, as shown in FIG. 3, when the feed water temperature in the hot well tank is less than 50 ° C. Is not enough to reduce the amount of dissolved oxygen in the feed water, making it unnecessary to install a deaerator for make-up water and return water from the steam process. This is because there is a possibility that it cannot be reduced.

  Further, when the water supply temperature in the hot well tank exceeds 85 ° C., the amount of dissolved oxygen is further reduced, while the amount of water supplied to the hot well tank is increased, which may cause energy loss. Because. From such a viewpoint, the predetermined temperature is more preferably 55 ° C. or higher and 70 ° C. or lower.

  On the other hand, the controller controls the opening degree of the hot water shutoff valve 18 based on the atmospheric pressure in the hot well tank 1 detected by the tank pressure gauge 17, and the exhaust gas discharged from the turbine 43 of the gas turbine 40 by the economizer 21. The other part of the water supply heated by the gas is a space 3 above the liquid level of the water supply in the hot well tank 1 so that the air pressure in the hot well tank 1 is 0.1 kPA to 50 kPA (predetermined pressure). To supply. The feed water supplied to the upper space 3 is pressurized to about 1900 kPA, and is immediately flushed and vaporized by rapid decompression to 0.1 kPA to 50 kPA, and the level of the feed water in the hot well tank 1 The upper space 3 is filled. The full steam is discharged from the vent portion 4 into the atmosphere, and the pressure in the space 3 above the liquid level is always maintained at 0.1 kPA to 50 kPA.

  In this way, by filling the space 3 above the liquid level of the hot well tank 1 with steam having a pressure of 0.1 kPA to 50 kPA, the entry of outside air into the hot well tank 1 is prevented, and the water supply comes into contact with the outside air. Can be prevented. Thereby, the dissolved oxygen amount of the feed water stored in the hot well tank 1 can be significantly reduced. This eliminates the need to install a deaerator for make-up water and return water from the steam process, which is required in conventional combined power plant water supply systems. Can be greatly reduced. As a result, significant cost reductions can be achieved in equipment costs, energy loss, maintenance costs, and operating costs.

  Moreover, since steam is generated using the water supply heated by the economizer 21, a self-contained system is formed, and a water supply system that makes more effective use of the exhaust heat of the gas turbine 40 can be constructed. It is desirable that the air pressure in the liquid surface upper space 3 of the water supply in the hot well tank 1 is 0.1 kPA to 50 kPA. This is when the air pressure in the liquid surface upper space 3 is less than 0.1 kPA, This is because the intrusion of outside air into the hot well tank 1 cannot be sufficiently prevented, and the dissolved oxygen content of the makeup water stored in the hot well tank may not be significantly reduced. When the air pressure in the upper space 3 exceeds 50 kPA, the amount of water supplied to the hot well tank increases, resulting in energy loss, and the problem of pressure resistance of the hot well tank itself. This is because of this. From such a viewpoint, it is more desirable that the air pressure in the upper space 3 is 1 kPA or more and 5 kPA or less.

  A second best mode for carrying out the combined power plant of the present invention will be described in detail with reference to FIG.

  As shown in FIG. 5, a constant flow valve (second flow control valve) that supplies the water supplied by the economizer 21 of the exhaust heat recovery boiler 20 while controlling the flow rate into the space 3 above the liquid level of the hot well tank 1. ) 61 or a general valve having the same function, and a self-acting check valve 62 which is disposed in the vent portion 4 of the hot well tank 1 and prohibits the backflow of the atmosphere into the space 3 above the liquid level. Accordingly, the air pressure in the space 3 above the liquid surface in the hot well tank 1 may be maintained at the predetermined pressure.

  The check valve 61 prevents intrusion of outside air into the hot well tank 1 and adjusts the flow rate of the constant flow valve 61 so that the constant flow valve 61 and the check valve 61 work together to form a hot well. It is also possible to keep the vapor pressure in the upper liquid level space 3 in the tank 1 at the predetermined pressure. With such a configuration, the liquid level upper space 3 in the hot well tank 1 can be easily filled with the steam of the predetermined pressure. Others are the same as the above-mentioned first best mode.

  The water supply temperature in the hot well tank 1 is not necessarily 50 ° C. or higher and 85 ° C. or lower, and the air pressure in the space 3 above the liquid surface in the hot well tank 1 is 0.1 kPA or higher. It need not be less than 50 kPA. Moreover, the above-mentioned combined power generation plant is only an example, and various modifications are possible based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a first best mode for carrying out a combined power plant of the present invention. It is a schematic diagram which shows the power generation system of a combined power generation plant. It is a schematic diagram which shows another electric power generation system. It is a graph which shows the solubility of oxygen with respect to pure water. It is a schematic diagram which shows the 2nd best form for implementing the combined power generation plant of this invention. It is a trial figure which shows the conventional combined power generation plant.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot well tank 2 Heat exchanger 3 Liquid level space 4 Vent part 10 Supply water supply line 11 Process return water supply line 12 Turbine condensate supply line 14 Water supply pump 15 Water supply thermometer 16 Temperature control valve 17 In tank Pressure gauge 18 High-temperature water shut-off valve 20 Waste heat recovery boiler 21 Economizer 22 Evaporator 23 Superheater 24 Steam drum 25 Steam separator 27 Temperature reducer 30 Steam turbine 31 Speed governor 32 Condenser 33 Vacuum pump 34 Condensate pump 40 Gas turbine 41 Compressor 42 Combustor 43 Turbine 44 Governor 45 Motor 46 Gas compressor 50, 51, 52 Generator 61 Constant flow valve 62 Self-powered check valve 100 Waste heat recovery boiler 101 Economizer 102 Evaporator 103 Superheater 110 Hot Well Tank 111 Liquid Level Upper Space 112 Deaerator 113 Water Supply Pump 114 Spirit

Claims (6)

  A combined power plant in which a generator (50, 51, 52) is rotationally driven by a steam turbine (30) and a gas turbine (40), wherein the combined power plant uses the exhaust gas of the gas turbine to drive the steam turbine. An exhaust heat recovery boiler (20) having an economizer (21) for generating superheated steam for rotational driving, and a hot well tank (1) for storing water to be supplied to the economizer, the hot well The tank has a heating means (2) for heating the water supply to be stored to a predetermined temperature, and the heating means uses the water supply heated by the economizer as a heat source.   A combined power plant in which a generator (50, 51, 52) is rotationally driven by a steam turbine (30) and a gas turbine (40), wherein the combined power plant uses the exhaust gas of the gas turbine to drive the steam turbine. An exhaust heat recovery boiler (20) having an economizer (21) for generating superheated steam for rotational driving, and a hot well tank (1) for storing water to be supplied to the economizer, the hot well The tank has heating means (2) for heating the water supply to be stored to a predetermined temperature, and the liquid surface upper space (3) for storing water is filled with steam at a predetermined pressure, and the heating means Supply water heated by an economizer is used as a heat source, and the steam supplies water heated by the economizer. Combined power plant, characterized in that to occur are.   Temperature detection means (15) for detecting the temperature of the water supply in the hot well tank (1), and the economizer (21) heated by the economizer (21) based on the temperature of the water supply detected by the temperature detection means The combined power generation plant according to claim 1 or 2, further comprising first flow rate control means (16) for supplying feed water to the heating means (2) under flow rate control. The combined power plant according to any one of claims 1 to 3 , wherein the predetermined temperature is 50 ° C or higher and 85 ° C or lower.   A second flow rate control means for supplying the water supply heated by the economizer (21) by controlling the flow rate into the space (3) above the liquid level of the hot well tank (1) is provided. The combined power generation plant according to claim 2.   The combined power plant according to claim 2 or 5, wherein the predetermined pressure is 0.1 kPA or more and 50 kPA or less.

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