JP4926732B2 - Seal water recovery equipment - Google Patents

Description

The present invention relates seal water recovery set to recover water seal for instrument seal in the power generating plant equipped with a condenser for condensing the exhaust steam Bei.

  In a power generation facility that generates electricity with a steam turbine driven by steam produced by a boiler, there is a system that condenses exhaust steam that has finished work in the steam turbine into a condensate by condensing it, and supplies the condensate to the boiler. Is provided. Further, in the power generation facility, sealed water is used to perform various seals such as a rotating part such as a feed pump driven by steam, and the sealed water used for the seal is collected in a sealed water recovery tank. Furthermore, in power generation facilities, steam is used to drive equipment in addition to steam for driving a steam turbine, and steam is generated by recovering exhaust heat to secure these steam. Is provided. In general, water is supplied to the steam generator from a water supply tank that is provided in the system and stores a part of the water supplied to the boiler.

  In the power generation facility, the sealed water collected in the sealed water collection tank is collected by a pressure difference in a vacuum condenser during operation, and the sealed water in the sealed water collection tank is restored without using power for collection. It is designed to circulate in a water container. Not only thermal power generation equipment but also nuclear power generation equipment and the like, sealing water for sealing is circulated to a condenser after being collected in a sealing water recovery tank (see, for example, Patent Document 1).

  Generally, the temperature of the sealing water used for sealing is relatively high (for example, 40 ° C. to 60 ° C.), but since it is recovered in a vacuum condenser, the temperature is lowered without recovering thermal energy. The current situation is that In addition, water is supplied from a water supply tank to a steam generation facility that generates steam used for driving devices, and a part of the water supplied to the boiler is sent to the water supply tank. For this reason, the water supply to the boiler is reduced by that amount, which hinders the factor of improving the efficiency of the entire power generation facility.

JP-A-7-128487

  The present invention has been made in view of the above situation, and provides a sealed water recovery facility that can effectively recover the thermal energy of the sealed water recovered in the sealed water recovery tank and improve the efficiency of the power generation facility. With the goal.

  In order to achieve the above object, the sealed water recovery facility of the present invention according to claim 1 is a steam turbine driven by steam from a boiler, a condenser for condensing exhaust steam that has finished work in the steam turbine, Condensate supply means for pressure-feeding the condensate of the condenser to the water supply system, water supply means for pressure-feeding water from the water supply system to the boiler, and condensate from the condensate supply means to the sealing mechanism of the equipment including the water supply means A sealing system that supplies a part of the water as sealing water, a sealed water recovery tank that stores the return water of the sealing system, and a part of the condensate from the condensate supply means are stored as the water supply for the steam generation means. In a power generation facility equipped with a water supply tank, the water stored in the seal water recovery tank is more than the temperature of the water supply on the outlet side of the condensate supply means and the water supply system for pumping the water stored in the water recovery tank to the water supply tank. Allow water to flow through the sealed water supply system when the water temperature rises Characterized by comprising a that flow control valve.

  In the present invention according to claim 1, the water stored in the sealed water recovery tank having a relatively high temperature can be pumped to the water supply tank by the flow regulating valve, and the thermal energy of the sealed water can be effectively recovered. .

And the sealing water collection | recovery equipment of this invention which concerns on Claim 2 is a sealing water collection | recovery equipment of Claim 1, and is branched from the sealing water supply system, is provided, and the stored water of a sealing water collection tank is used as a condenser. Provided a return path for supplying water, a condensate flow restriction valve that allows water to flow through the return path at the time of startup, and a control means that controls the operation of the flow restriction valve and the condensate flow restriction valve in conjunction with each other. It is characterized by.

  In the present invention according to claim 2, at the time of start-up, the condensate flow regulation valve is opened by the control means, and the water stored in the sealed water recovery tank can be supplied to the condenser from the return path.

  In order to achieve the above object, a sealed water recovery facility of the present invention according to claim 3 is a steam turbine driven by steam from a boiler, a condenser for condensing exhaust steam that has finished work in the steam turbine, A condensate pump that pumps the condensate of the condenser to the heat exchanging means, a condensate booster pump that pressurizes the condensate heat exchanged by the heat exchanging means and pumps it to the deaerator, and deaerates by the deaerator Water supply pump for supplying the condensed condensate to the boiler, a sealing line for supplying a part of the condensate from the condensate booster pump to the equipment including the water supply pump as sealing water, and sealing from the equipment including the water supply pump. In a power generation facility comprising a sealed water recovery tank for storing the return water of the still water and a water supply tank for storing a part of the condensate pressurized by the condensate booster pump as feed water for the steam generating means, the sealed water recovery pump is provided. The water stored in the sealed water recovery tank is pumped to the water supply tank Flow control valve that allows the stored water to flow through the sealed water path when the temperature of the water stored in the sealed water recovery tank becomes higher than the temperature of the water path and the feed water at the outlet side of the condensate booster pump It is characterized by comprising.

  In this invention which concerns on Claim 3, when the temperature of the water stored in the sealing water collection | recovery tank is higher than the temperature of the feed water of the exit side of a condensate pressure | voltage rise pump, it is sealed water via a sealing water collection | recovery pump by a distribution control valve. The water stored in the recovery tank can be pumped to the water supply tank, and the thermal energy of the sealed water can be recovered effectively.

A sealed water recovery facility according to a fourth aspect of the present invention is the sealed water recovery facility according to the third aspect, wherein the stored water is branched from the sealed water path downstream of the sealed water recovery pump and condensates the stored water. A return path for supplying water to the vessel, a condensate flow restriction valve that allows water to flow through the return path at start-up, and a control means that controls the operation of the flow restriction valve and the condensate flow restriction valve in conjunction with each other. It is characterized by that.

  In the present invention according to claim 4, at the time of start-up, the condensate flow restriction valve is opened by the control means, and the water stored in the sealed water recovery tank can be supplied to the condenser from the return path.

The sealing water recovery method using the sealing water recovery apparatus of the present invention generates power with a steam turbine driven by steam generated by a boiler, and condenses exhaust steam that has finished work with the steam turbine by a condenser. and water, the power generating plant for supplying water condensate to the boiler, return the seal water subjected to sealing of the device and the water supply for steam generation.

Thereby, since the return of the relatively high-temperature sealed water that has sealed the device is used as water supply for generating steam, the thermal energy of the sealed water can be effectively recovered.

Sealing water recovery equipment of the present invention can improve the efficiency of effectively recovered to power generation equipment thermal energy of seal water collected in the sealing water recovery tank.

  FIG. 1 shows a schematic system of a power generation facility provided with a sealed water recovery facility according to an embodiment of the present invention.

  As shown in the figure, high-temperature and high-pressure steam is generated in the boiler 1 by burning the fuel at a high temperature, and the steam generated in the boiler 1 is sent to the steam turbine 2 to rotate the steam turbine 2 at high speed. Then, the generator 3 generates power. The exhaust steam that has finished work in the steam turbine 2 is condensed in the condenser 4 to be condensed water. Condensate in the condenser 4 is sent as a cooling medium to the heat exchanging means 6 by the condensate pump 5 and subjected to heat exchange, and then impurities are removed by the condensate demineralizer 14 and the pressure is increased by the condensate booster pump 7. And pumped to the deaerator 8.

  In the illustrated example, the heat exchange means 6 includes a heat exchanger 11, a ground condenser 12, an air extractor 13, and a condensate demineralizer 14. The heat exchanger 11 is a device for cooling the fluid in the system by condensate. The ground condenser 12 is a device for obtaining a pressure slightly lower than the atmospheric pressure in the labyrinth packing ring of the steam turbine 2, and the steam leaks and the steam leaks into the lubricating oil and the air leaks into the turbine exhaust chamber. It is configured to cool the air / steam mixer with condensate. The air extractor 13 is a device that extracts the air from the condenser 4 (steam piping system) and holds the condenser 4 in a vacuum, and has a structure that cools the air by the condensate and releases it to the atmosphere. .

  The heat-exchanged condensate is sent to the condensate demineralizer 14, and for example, the dissolved salts contained in the fresh water are removed by the ion exchange resin, and the high-purity water required as the makeup water for the boiler 1 is obtained. . High-purity water obtained by the condensate demineralizer 14 is pumped to the deaerator 8 by the condensate booster pump 7. In the deaerator 8, the feed water is directly heated by turbine extraction, and non-condensable gases such as oxygen, carbon, and carbon dioxide in the feed water are removed. The feed water from which the non-condensable gas has been removed by the deaerator 8 is pumped to the boiler 1 by the boiler feed pump 18.

  The boiler feed pump 18 is configured to be driven by steam, and sealed water is supplied for sealing a rotation support portion and the like. Sealed water is supplied from a sealing line 21 branched in the downstream of the condensate booster pump 7, and recovered from the return line 22 to the sealed water recovery tank 23. Sealed water of equipment in the system other than the boiler feed pump 18 is also collected in the sealed water recovery tank 23.

  On the other hand, the power generation facility is provided with steam generating means (not shown) for generating steam used for driving devices in the system, and water stored in the water supply tank 24 is supplied to the steam generating means. A part of the condensate whose pressure has been increased by the condensate booster pump 7 is supplied to the water supply tank 24 from the water supply line 25.

  In the power generation facility described above, the return of the sealed water that has sealed the device is stored in the sealed water recovery tank 23, and the stored water in the sealed water recovery tank 23 is pumped to the water supply tank 24 to generate steam generated water. Seal water recovery equipment is provided.

  That is, the sealed water recovery tank 23 is connected to the water supply tank 24 by the sealed water path 31, and the sealed water path 31 is provided with the sealed water recovery pump 32. A flow restriction valve 33 is provided in the sealed water path 31 downstream of the seal water recovery pump 32, and is stored in the seal water recovery tank 23 when the seal water recovery pump 32 is driven in a state where the flow restriction valve 33 is opened. The return water of the sealed water is pumped to the water supply tank 24.

  A return path 34 is provided by branching from the sealed water path 31 downstream of the sealed water recovery pump 32, and the return path 34 is connected to the condenser 4. The return path 34 is provided with a condensate flow restriction valve 35, and the condensate flow restriction valve 35 is opened in a state where the flow restriction valve 33 is closed, so that the sealed water stored in the seal water recovery tank 23 is returned. Water is sent to the condenser 4 by negative pressure. The operations of the flow restriction valve 33 and the condensate flow restriction valve 35 are controlled in conjunction with a command from the control means 36.

  Further, the seal water recovery tank 23 is provided with first temperature detecting means 41 for detecting the temperature of the return water of the stored seal water. Second temperature detecting means 42 for detecting the temperature of the water is provided. Detection information of the first temperature detection means 41 and the second temperature detection means 42 is input to the control means 36.

  When the temperature detected by the first temperature detecting means 41 is higher than the temperature detected by the second temperature detecting means 42 (for example, when the temperature is increased by 5 ° C. or more), the flow restriction valve 33 is opened. The control means 36 controls the operation so that the condensate flow restriction valve 35 is closed. Thereby, the stored water of the sealing water with comparatively high temperature is sent to the water supply tank 24, and the thermal energy of sealing water can be collect | recovered.

  At the time of start-up or the like, the temperature detected by the first temperature detecting means 41 is lower than the temperature detected by the second temperature detecting means 42, so that the flow restriction valve 33 is closed and the condensate flow restriction valve 35. Is opened, and the stored water is sent to the condenser 4 to secure the water supply amount in the system. The sealed water recovery pump 32 is always automatically operated, the sealed water recovery pump 32 is activated when the condenser 4 is not vacuumed at the time of startup, and the vacuum is maintained when the condenser 4 is in a vacuum (during normal operation). The level of the sealed water recovery tank 23 is controlled.

  The first temperature detection means 41, the second temperature detection means 42, the return path 34, and the condensate flow restriction valve 35 may be omitted, and the entire amount of water stored in the seal water recovery tank 23 may be supplied to the water supply tank 24. Is possible.

  In the power generation facility described above, the steam turbine 2 is driven by the steam produced by the boiler 1 and power is generated by the generator 3. The exhaust steam that has finished work in the steam turbine 2 is condensed in the condenser 4, and the condensed water is sent to the heat exchanger 11, the ground condenser 12, the air extractor 13, and the condensate demineralizer 14 by the condensate pump 5. Then, the heat is exchanged, and the pressure is pumped to the deaerator 8 by the condensate booster pump 7. The water supply deaerated by the deaerator 8 is supplied to the boiler 1 by a boiler water supply pump 18.

  During the operation of the power generation facility, the return of the sealed water that has sealed the water supply tank 24 and other devices is stored in the sealed water recovery tank 23, and the stored water in the sealed water recovery tank 23 is pumped to the water supply tank 24. That is, the sealed water is supplied from the sealing line 21 branched in the downstream of the condensate booster pump 7 to the water supply tank 24, and the sealed water is recovered from the return line 22 to the sealed water recovery tank 23. The water supply tank 24 is supplied with water supplied by the condensate booster pump 7 through a water supply line 25.

  Temperature information of the first temperature detection means 41 and the second temperature detection means 42 is input to the control means 36, and the temperature detected by the first temperature detection means 41 is higher than the temperature detected by the second temperature detection means 42. When the temperature is high, that is, when the temperature of the seal water recovered in the seal water recovery tank 23 is higher than the temperature of the feed water boosted by the condensate booster pump 7, the flow restriction valve 33 is opened and the condensate flow is performed. The return water of the sealing water recovered in the sealing water recovery tank 23 with the regulating valve 35 closed is supplied to the water supply tank 24.

  During normal operation, the temperature of the water stored in the sealed water recovery tank 23 is about 50 ° C. to 60 ° C., the temperature of the water supplied by the condensate booster pump 7 is about 30 ° C. to 35 ° C., and the water supply tank 24 The temperature of the water supply is about 80 ° C.

  For this reason, the water stored in the sealing water recovery tank 23 having a relatively high temperature can be pumped to the water supply tank 24, and the thermal energy of the sealing water can be effectively recovered. Further, the amount of water supplied to the water supply tank 24 that has been pressurized by the condensate booster pump 7 can be reduced by the amount of water stored in the sealed water recovery tank 23 being supplied to the water supply tank 24. As a result, the efficiency of the power generation facility can be improved.

  When the temperature detected by the first temperature detecting means 41 is lower than the temperature detected by the second temperature detecting means 42 at the time of start-up or the like, that is, the temperature of the feed water boosted by the condensate booster pump 7 is sealed. When the temperature of the sealed water recovered in the water recovery tank 23 is low, the flow restriction valve 33 is closed and the condensate flow restriction valve 35 is opened, and the stored water is sent to the condenser 4. The amount of water supply in the system is secured.

The present invention can be utilized in the industrial fields of seal water recovery equipment for recovering the water seal for instrument seal in a power plant equipped with condenser for condensing the exhaust steam.

It is a schematic system diagram of the power generation equipment provided with the seal water recovery equipment according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Boiler 2 Steam turbine 3 Generator 4 Condenser 5 Condensate pump 6 Heat exchange means 7 Condensate booster pump 8 Deaerator 11 Heat exchanger 12 Ground condenser 13 Air extractor 14 Condensate demineralizer 18 Boiler feed pump 21 Sealing Line 22 Return Line 23 Sealed Water Recovery Tank 24 Water Supply Tank 25 Water Supply Line 31 Sealed Water Path 32 Sealed Water Recovery Pump 33 Flow Restriction Valve 34 Return Path 35 Condensate Flow Restriction Valve 36 Control Unit

Claims (4)

A steam turbine driven by steam from the boiler;
A condenser that condenses the exhaust steam that has finished work in a steam turbine;
Condensate supply means for pumping the condensate of the condenser to the water supply system;
Water supply means for pumping the water supply system water to the boiler;
A sealing system for supplying a part of the condensate from the condensate supply means to the sealing mechanism of the equipment including the water supply means as sealing water;
A sealed water recovery tank for storing the return water of the sealing system;
In a power generation facility equipped with a water supply tank for storing a part of the condensate from the condensate supply means as water supply for the steam generation means,
A sealed water supply system for pumping the water stored in the sealed water recovery tank to the water supply tank;
A flow regulating valve that allows water to flow to the sealed water supply system when the temperature of the water stored in the sealed water recovery tank becomes higher than the temperature of the feed water on the outlet side of the condensate supply means. Sealed water collection facility characterized by that. In the sealed water recovery facility according to claim 1,
A return path that branches off from the sealed water supply system and feeds the water stored in the sealed water recovery tank to the condenser;
A condensate flow restriction valve that allows water to flow through the return path at startup, and
And a control means for controlling the operation of the flow restriction valve and the condensate flow restriction valve in conjunction with each other. A steam turbine driven by steam from the boiler;
A condenser that condenses the exhaust steam that has finished work in a steam turbine;
A condensate pump that pumps the condensate from the condenser to the heat exchange means;
A condensate booster pump that boosts the condensate heat-exchanged by the heat exchange means and pumps it to the deaerator;
A water supply pump for supplying the boiler with the condensate deaerated by the deaerator,
A sealing line for supplying a part of the condensate from the condensate booster pump to the equipment including the feed water pump as sealing water;
Power generation comprising: a sealed water recovery tank for storing return water of sealing water from a device including a water supply pump; and a water supply tank for storing a part of the condensate pressurized by a condensate booster pump as water supply for steam generation means In equipment,
A sealed water path for pumping the water stored in the sealed water recovery tank to the water supply tank via the sealed water recovery pump;
A flow regulating valve that allows the stored water to flow through the sealed water path when the temperature of the water stored in the sealed water recovery tank becomes higher than the temperature of the feed water at the outlet side of the condensate booster pump. Sealed water collection facility characterized by that. In the sealed water recovery facility according to claim 3,
A return path that branches off from the sealed water path downstream of the sealed water recovery pump and feeds the stored water to the condenser;
A condensate flow restriction valve that allows water to flow through the return path at startup, and
And a control means for controlling the operation of the flow restriction valve and the condensate flow restriction valve in conjunction with each other.

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