JP5121418B2 - Sealed water recovery system and power generation equipment having the same - Google Patents

Description

  The present invention relates to a sealed water recovery system and a power generation facility having the same, and is particularly useful when applied to a brackish water power generation facility.

  In a steam power generation system in which a generator is driven using a steam turbine as a prime mover, the steam that has worked in the steam turbine is condensed and returned to water by a condenser, and again through a condensate system such as a boiler by driving a condensate pump. Supplied to the steam generating means. On the other hand, in such a brackish water power generation system, sealed water is used to seal the rotating shafts of various rotating devices of the power generation equipment such as a steam turbine. As shown in FIG. 4, the sealed water provided for such use is accumulated in the sealed water recovery tank 1 from various places of the power generation facility. The sealed water collected in the sealed water recovery tank 1 is supplied to the condenser 5 through the sealed water recovery pipe 3 and the sealed water valve 4 by driving the sealed water recovery pump 2.

  In addition, the following patent documents exist as well-known documents which disclose this kind of sealed water recovery system.

JP-A-7-128487 JP-A-8-136165

  In the sealed water recovery system according to the prior art as described above, when the sealed water recovery pump 2 fails, the sealed water recovery pump 2 cannot be driven and the sealed water is recovered in the condenser 5. Cause the problem of not being able to. Furthermore, when the sealed water cannot be collected in the condenser 5, there also arises a problem that the sealed water overflows from the sealed water collection tank 1 to the outside.

  On the other hand, a measure of a spare sealing water recovery pump 2 in case of a failure can be considered, but in this case, a new problem that the equipment cost increases is caused.

  An object of the present invention is to provide a sealed water recovery system capable of recovering sealed water in a condenser even in the event of a failure of the sealed water recovery pump.

The first aspect of the present invention for achieving the above object is as follows:
A sealed water recovery tank for storing sealed water accumulated from various places of the power generation facility;
The sealed water collected in the sealed water recovery tank by driving is disposed in the middle of the sealed water recovery pipe that communicates between the sealed water recovery tank and the condenser. A sealed water recovery pump that supplies the condenser;
A bypass line that bypasses the sealed water recovery pump and communicates the sealed water recovery tank and the sealed water recovery line ;
A check valve disposed in the bypass line to allow only the flow of sealed water from the sealed water recovery tank toward the condenser;
A seal valve disposed in the seal water collection pipe so that the amount of seal water flowing into the condenser can be adjusted;
A water level control means for detecting whether or not the level of the sealed water stored in the sealed water recovery tank is within a predetermined normal operating range and adjusting the opening of the seal valve based on the detected water level; ,
A first sensor for detecting that the level of the sealed water stored in the sealed water recovery tank exceeds the upper limit of the normal operation range, and detecting that the set water level set in the normal operation range is reached. A water level switch means having a second sensor and a third sensor for detecting that the lower limit of the normal operation range has been exceeded, and controlling driving of the pump based on the water level detected by the first to third sensors And
When the sealing water level detected by the sensor and the first to third sensors is within the normal operation range, the opening level of the sealing valve is adjusted by the water level control means so as to be a set water level, and While the sealed water recovery pump is stopped by the water level switch means, the sealed water is recovered via the bypass line by the negative pressure of the condenser,
When the water level of the sealed water exceeds the upper limit, the sealed water recovery pump is activated by the water level switch means to collect the sealed water via the sealed water recovery pipeline, and the water level is lowered. If it falls within the normal operating range, stop the sealing water recovery pump and perform sealing water recovery only by the bypass line again,
Furthermore, when the water level of the sealed water falls below the lower limit of the normal operation range, the sealed water recovery system is configured to stop the recovery of the sealed water with the seal valve in a fully closed state. It is in.
The second aspect of the present invention is:
The power generation facility includes the sealed water recovery system described in the first aspect.

  According to the present invention, even if the seal water recovery pump stops due to a failure or the like, the seal water in the seal water recovery tank is sucked and introduced into the condenser with a negative pressure acting on the bypass line via the condenser. be able to. As a result, it is possible to prevent the seal water from overflowing in the seal water recovery tank and to continue the recovery of the seal water to the condenser.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same parts as those in the prior art shown in FIG.

  FIG. 1 is a block diagram showing an outline of a power generation facility having a sealed water recovery system according to an embodiment of the present invention. As shown in the figure, the power generation facility includes a boiler 100 in which fuel F is burned at a high temperature, supplies steam generated in the boiler 100 to a steam turbine 101, and drives the steam turbine 101. To drive the generator 102 to generate predetermined power. On the other hand, the steam that has worked in the steam turbine 101 is condensed in the condenser 5 and returned to water. The water condensed in the condenser 5 returns to the boiler 100 through the condensate system 103 which is a pipe, and circulates again as steam. In the middle of the condensate system 103, a condensate pump 104, a demineralizer 105, a deaerator 106, and a feed water pump 107 are disposed. The feed water pump 107 pumps the boiler 100.

  Furthermore, the power generation facility according to the present embodiment includes a seal water recovery system for collecting and recovering the seal water used for sealing the rotary shafts of various rotating devices of the power generation facility such as the steam turbine 101 in the seal water recovery tank 1. Have. The sealed water recovery system according to the present embodiment is similar to the conventional sealed water recovery tank 1, sealed water recovery pump 2, sealed water recovery pipeline 3, and sealed water valve 4 in addition to the bypass pipeline 6, check. It has a valve 7, a water level control device 8 and a water level switch device 10.

  FIG. 2 is an explanatory view showing the seal water recovery system in the power generation facility shown in FIG. As clearly shown in FIG. 2 together with FIG. 1, the sealed water recovery tank 1 stores sealed water collected from various places of the power generation facility. The seal water recovery pump 2 is disposed in the middle of a seal water recovery pipe 3 that communicates between the seal water recovery tank 1 and the condenser 5. By driving the seal water recovery pump 2, the seal water accumulated in the seal water recovery tank 1 is supplied to the condenser 5 through the seal water recovery pipe 3. The bypass line 6 bypasses the seal water recovery pump 2 to connect the seal water recovery tank 1 and the seal water recovery pipe line 3. In the middle of the bypass line 6, a check valve 7 that allows only the flow of sealed water from the sealed water recovery tank 1 to the condenser 5 is disposed. The water level control device 8 detects the water level of the seal water stored in the seal water recovery tank 1 and adjusts the opening of the seal valve 4 so that the water level becomes a preset water level. For this reason, the water level control device 8 has a sensor 9 that can be immersed in the sealed water in the sealed water recovery tank 1, and based on the level of the sealed water detected by the sensor 9, the opening degree of the sealing valve 4 is adjusted. Adjust (details of the adjustment will be described later in detail). The water level switch device 10 detects the water level of the seal water stored in the seal water recovery tank 1 by means of the sensors 11a, 11b, and 11c, and transmits a predetermined alarm based on the detected water level and drives the seal water recovery pump 2. Control the stop. Here, the sensors 11a to 11c are arranged at different positions in the sealed water recovery tank 1, and are arranged as sensors 11a, 11b, and 11c from the higher position in the sealed water recovery tank 1. As a result, appropriate control according to the water level is performed, but specific details will be described later.

  In this embodiment, as shown in FIG. 3, the water level of the sealed water in the sealed water recovery tank 1 detected by the sensor 9 and the sensors 11a, 11b, and 11c is set water level (± 0 mm) +150 (mm). When in the range A (normal operation range) between (± 0 mm) and 250 (mm), the opening degree of the sealing valve 4 is adjusted so that the set water level is reached, and the sealing water recovery pump 2 is stopped. The sealed water is recovered via the bypass line 6 by the negative pressure of the condenser 5.

  On the other hand, if the recovery level through the bypass line 6 is not in time, and the water level of the sealed water exceeds the upper limit of the range A and reaches the range B, as shown in FIG. The water recovery pump 2 is activated and the sealed water is recovered also through the sealed water recovery pipe 3. As a result, when the water level falls and falls within the range A, the seal water recovery pump 2 is stopped and the seal water is recovered again only by the bypass pipe 6.

  When the water level of the sealed water falls below the lower limit of range A, the sealing valve 4 is fully closed and the recovery of the sealed water is stopped.

  Table 1 summarizes a series of such adjustment and control modes.

  According to the present embodiment, even if the seal water recovery pump 2 is stopped due to a failure or the like, the seal water in the seal water recovery tank 1 is sucked back by the negative pressure acting on the bypass pipe 6 via the condenser 5. It can be introduced into the water vessel 5.

  As a result, even if the seal water recovery pump 2 is stopped, it is possible to prevent the seal water from overflowing in the seal water recovery tank 1 and to continue the recovery of the seal water to the condenser 5 well.

  On the other hand, when the sealed water collection pump 2 is driven, the check valve 7 can prevent the sealed water from flowing back from the sealed water collection pipe 3 to the sealed water collection tank 1 through the bypass pipe 6. .

  In the power generation facility according to this embodiment, there is a case where a sufficient amount of sealed water cannot be introduced into the condenser 5 only by negative pressure without driving the sealed water recovery pump 2. This is because the vacuum degree of the condenser 5 may be insufficient to suck a sufficient amount of sealed water. For this reason, in this embodiment, the running cost required for driving the seal water recovery pump 2 is reduced by using the negative pressure to recover through the bypass line 6 at normal times when the recovery capability is low, Only when the water level becomes abnormal, recovery by driving the sealed water recovery pump 2 is also performed.

  In the above embodiment, the power generation facility using a boiler as a steam generation source has been described. However, the present invention is not limited to this. Sealed water recovery is performed by collecting the sealed water in a sealed water recovery tank and collecting it in a condenser. Any type of power generation equipment having a system can be applied.

  The present invention can be used in an industrial field in which power generation equipment is manufactured and sold, and an industrial field in which maintenance and inspection are performed.

It is a block diagram which shows the outline of the electric power generation equipment which concerns on embodiment of this invention. It is explanatory drawing which expands and shows the outline of the sealing water collection | recovery system which concerns on embodiment of this invention. It is explanatory drawing which shows the relationship between the water level of the sealing water collection | recovery tank in embodiment of this invention, and control. It is explanatory drawing which shows the outline of the sealing water collection | recovery system which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sealed water recovery tank 2 Sealed water recovery pump 3 Sealed water recovery pipeline 5 Condenser 6 Bypass pipeline 7 Check valve 8 Water level control device 10 Water level switch device 100 Boiler 101 Steam turbine 102 Generator 103 Condensate system

Claims (2)

A sealed water recovery tank for storing sealed water accumulated from various places of the power generation facility;
The sealed water collected in the sealed water recovery tank by driving is disposed in the middle of the sealed water recovery pipe that communicates between the sealed water recovery tank and the condenser. A sealed water recovery pump that supplies the condenser;
A bypass line that bypasses the sealed water recovery pump and communicates the sealed water recovery tank and the sealed water recovery line ;
A check valve disposed in the bypass line to allow only the flow of sealed water from the sealed water recovery tank toward the condenser;
A seal valve disposed in the seal water collection pipe so that the amount of seal water flowing into the condenser can be adjusted;
A water level control means for detecting whether or not the level of the sealed water stored in the sealed water recovery tank is within a predetermined normal operating range and adjusting the opening of the seal valve based on the detected water level; ,
A first sensor for detecting that the level of the sealed water stored in the sealed water recovery tank exceeds the upper limit of the normal operation range, and detecting that the set water level set in the normal operation range is reached. A water level switch means having a second sensor and a third sensor for detecting that the lower limit of the normal operation range has been exceeded, and controlling driving of the pump based on the water level detected by the first to third sensors And
When the sealing water level detected by the sensor and the first to third sensors is within the normal operation range, the opening level of the sealing valve is adjusted by the water level control means so as to be a set water level, and While the sealed water recovery pump is stopped by the water level switch means, the sealed water is recovered via the bypass line by the negative pressure of the condenser,
When the water level of the sealed water exceeds the upper limit, the sealed water recovery pump is activated by the water level switch means to collect the sealed water via the sealed water recovery pipeline, and the water level is lowered. If it falls within the normal operating range, stop the sealing water recovery pump and recover the sealing water only by the bypass line again,
Furthermore, when the water level of the sealed water falls below the lower limit of the normal operation range, the sealed water recovery system is configured to stop the recovery of the sealed water with the seal valve in a fully closed state. . A power generation facility comprising the sealed water recovery system according to claim 1 .

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