JP2017133403A - Method for cooling bearing cooling water in power generation plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately maintain a temperature of bearing cooling water even when a temperature of seawater is increased.SOLUTION: A power generation facility comprises a steam condenser 10 which condenses exhaust steam of a steam turbine driving a generator through heat exchange with seawater and a bearing cooling water cooler 11 which cools bearing cooling water used for cooling a bearing of the steam turbine through the heat exchange with cooling water. In a method for cooling the bearing cooling water, the seawater and industrial water having a temperature lower than the same is used as the cooling water and a ratio between the seawater and the industrial water in the cooling water is controlled on the basis of the temperatures of the seawater, the industrial water and the bearing cooling water. For example, when the temperature of the seawater is increased in summer, the ratio of the industrial water to the seawater is increased.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for cooling bearing cooling water in a power generation facility, and more particularly to a technique for maintaining the temperature of bearing cooling water at an appropriate level.

  Patent Document 1 discloses that a secondary cooling water circulation path (secondary circulation flow path of a secondary heat exchanger) is provided during operation of the power generation plant in order to ensure sufficient inspection time of the turbine bearing lubricating oil cooling facility in the power generation plant. ) Circulates seawater to cool the primary cooling water, and when stopping the power plant, perform a turning process to rotate the turbine at a low speed to prevent thermal deformation of the turbine. It describes that industrial water is supplied to a water circulation path (secondary circulation path) to cool the primary cooling water.

  In Patent Document 2, in order to provide a system that generates power using cooling water discharged from various factories or the like and surplus industrial water, a hydroelectric power generation system includes a water storage tank capable of storing water therein, a bearing The first water supply system that collects the cooling water discharged from the cooling water cooler and supplies it to the water storage tank, the second water supply system that supplies excess industrial water to the water storage tank, and the water stored in the water storage tank It is described that the structure includes a water discharge system to be discharged and a hydroelectric generator provided in the water discharge system and capable of generating power by the hydraulic power of the discharged water.

  In Patent Document 3, when the power generation unit is stopped, the first cooling target device and the second cooling target device are cooled when the power generation unit is stopped in order to eliminate waste of operating two cooling water pumps. The first cooling target device in the first cooling water supply system related to the boiler and the generator is included in the second cooling water supply system that supplies the cooling water to the second cooling target device related to the turbine. Configured to supply cooling water to the second cooling water supply system with a single bearing cooling pump, and to distribute the cooling water to the first cooling water supply system and the second cooling water supply system. It is described that the adjustment is made according to the opening of the gate valve.

JP 2007-40253 A JP 2012-57528 A JP 2014-92079 A

  In power generation facilities such as thermal power plants, seawater is used to cool bearing cooling water used to cool equipment such as oil coolers and compressors. Here, when the temperature of the atmosphere or seawater rises in summer or the like, the heat exchange efficiency of a heat exchanger (hereinafter referred to as a bearing cooling water cooler) that performs heat exchange between the bearing cooling water and seawater decreases. This is dealt with, for example, by increasing the amount of cooling water (increasing the opening of the cooling water valve, additional activation of the seawater pump, etc.). Further, for example, the heat exchange efficiency is improved by cleaning the bearing cooling water cooler before the summer comes.

  However, when the seawater temperature rises greatly, there is a possibility that the cooling of the oil temperature of the equipment may be hindered, and there may be a situation in which the load must be suppressed.

  The present invention has been made in view of such a background, and provides a cooling method for bearing cooling water in power generation equipment that can maintain the temperature of bearing cooling water at an appropriate level even when the seawater temperature rises. The purpose is that.

  One aspect of the present invention for achieving the above object is a condenser for condensing and condensing exhaust steam of a steam turbine that drives a generator by exchanging heat with seawater, and a bearing for the steam turbine. A bearing cooling water cooler that cools the bearing cooling water used for cooling the cooling water by exchanging heat with the cooling water. Using sea water and industrial water having a temperature lower than that of the sea water, the ratio of the sea water and the industrial water in the cooling water is determined based on the temperature of the sea water, the temperature of the industrial water, and the temperature of the bearing cooling water. We will control it.

  According to the present invention, the temperature of the bearing cooling water can be kept appropriate even when the seawater temperature rises.

  Another one of the present invention is a cooling method for the bearing cooling water, wherein when the temperature of the seawater rises, control is performed so that the ratio of industrial water to seawater in the cooling water increases. I will do it.

  According to the present invention, for example, when the seawater temperature rises in summer or the like, the temperature rise of the bearing cooling water can be suppressed.

  Another aspect of the present invention is the cooling method for the bearing cooling water, wherein when the temperature of the seawater is a predetermined value or less, the ratio of industrial water to seawater in the cooling water is reduced. Control.

  According to the present invention, for example, in the winter season, when the temperature of the seawater is appropriate or decreases, the industrial water is appropriately controlled so that the ratio of the industrial water contained in the cooling water is smaller than that of the seawater. The amount of water intake can be suppressed.

  In addition, the subject which this application discloses, and its solution method are clarified by the column of the form for inventing, and drawing.

  According to the present invention, the temperature of the bearing cooling water can be kept appropriate even when the seawater temperature rises.

It is a figure which shows the structure (part) of the power generation equipment of a thermal power plant.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a part of the configuration of power generation equipment of a thermal power plant. The power generation equipment includes a combustion furnace that burns fuel, a water supply device, a ventilation device, a desulfurization device, and the like, and a steam turbine that generates power for operating the generator by steam supplied from the boiler (all not shown) , A condenser 10 that condenses and condenses exhaust steam from the steam turbine, a generator (not shown) that generates power using the power of the steam turbine, and the like.

  The bearing cooling water cooler 11 shown in the figure exchanges heat with cooling water for bearing cooling water used for cooling a cooling target 12 (oil cooler for turbine oil that lubricates turbine bearings, control compressors, in-house compressors, etc.). To cool.

  The circulating water pump 21 pumps up seawater and supplies the pumped seawater to the condenser 10 and the seawater booster pump 22.

  The seawater booster pump 22 boosts the seawater pumped up by the circulating water pump 21 and supplies it to the bearing cooling water cooler 11.

  The industrial water booster pump 23 shown in the figure boosts the industrial water pumped up from a river or the like and supplies it to the bearing cooling water cooler 11. In addition, as industrial water, the surplus part of the river water lower temperature than seawater currently used with the desulfurization apparatus etc. can be utilized, for example.

  The bearing cooling water pump 24 shown in the figure boosts the bearing cooling water and circulates and supplies it to the bearing cooling water cooler 11.

  During operation of the power generation facility, seawater is pumped from the intake 31 by the circulating water pump 21 and supplied to the condenser 10. The seawater supplied to the condenser 10 circulates in the water chamber of the condenser 10 and exchanges heat with the exhaust steam from the steam turbine, and is then led to the water discharge port 32 and released to the sea.

  Part of the seawater pumped up by the circulating water pump 21 flows into the seawater booster pump 22. The seawater that has flowed into the seawater booster pump 22 is boosted here and then supplied to the bearing cooling water cooler 11 as cooling water that exchanges heat with the bearing cooling water.

  The industrial water pumped up by the industrial water booster pump 23 is mixed with the seawater supplied from the seawater booster pump 22 and supplied to the bearing cooling water cooler 11 as cooling water for heat exchange with the bearing cooling water.

  The bearing cooling water pump 24 circulates and supplies bearing cooling water to the bearing cooling water cooler 11 and the cooling target 12.

  The cooling water (seawater and industrial water) supplied to the bearing cooling water cooler 11 is heat-exchanged with the bearing cooling water here, and then led to the water discharge port 32 and discharged to the sea.

  A seawater flow rate control valve 41 for adjusting the flow rate of the seawater supplied to the bearing cooling water cooler 11 as the cooling water is supplied to the supply line of the seawater boosted by the seawater boosting pump 22 to the bearing cooling water cooler 11. Is provided.

  An industrial water flow rate for adjusting the flow rate of the industrial water supplied as the cooling water to the bearing cooling water cooler 11 is supplied to the bearing cooling water cooler 11 of the industrial water boosted by the industrial water boosting pump 23. A control valve 42 is provided.

  A seawater temperature sensor S <b> 1 that measures seawater temperature T <b> 1 is provided in the supply line of the seawater boosted by the seawater booster pump 22 to the bearing cooling water cooler 11.

  An industrial water temperature sensor S2 for measuring the temperature T2 of the industrial water is provided in the supply line to the bearing water cooler 11 of the industrial water boosted by the industrial water booster pump 23.

  A bearing cooling water temperature sensor S <b> 3 that measures the temperature T <b> 3 of the bearing cooling water is provided in the supply line to the bearing cooling water cooler 11 that has been boosted by the bearing cooling water pump 24.

  The openings of the seawater flow rate control valve 41 and the industrial water flow rate control valve 42 are the seawater temperature T1 measured by the seawater temperature sensor S1, the industrial water temperature T2 measured by the industrial water temperature sensor S2, and the bearing cooling water temperature. Based on the temperature T3 of the bearing cooling water measured by the sensor S3, it is automatically controlled (for example, automatically by feedback control by a control device including an information processing device) or manually.

  For example, in summer or the like, when the measured temperature T1 of the seawater temperature sensor S1 rises, the seawater flow rate control valve 41 and the industrial water flow rate control valve 42 are opened so that the ratio of industrial water to seawater in the cooling water increases. The degree is appropriately controlled, and the temperature rise of the bearing cooling water is suppressed. For example, the control device can efficiently and appropriately suppress the temperature rise of the bearing cooling water based on the seawater temperature T1, the industrial water temperature T2, and the bearing cooling water temperature T3 (promptly, industrial water In order to prevent the amount of water used from exceeding the limit amount), the respective opening degrees of the seawater flow rate control valve 41 and the industrial water flow rate control valve 42 are controlled.

  In addition, for example, in the winter season, when the temperature T1 of the seawater is appropriate or decreases (below a predetermined temperature), the flow rate of seawater is such that the proportion of industrial water contained in the cooling water becomes smaller than that of seawater. The opening degree of each of the control valve 41 and the industrial water flow rate control valve 42 is controlled, and the intake amount of industrial water is suppressed. For example, the controller controls the amount of industrial water to keep the temperature of the bearing cooling water appropriate based on the seawater temperature T1, the industrial water temperature T2, and the bearing cooling water temperature T3. In addition, the respective opening degrees of the seawater flow rate control valve 41 and the industrial water flow rate control valve 42 are controlled.

  As described above, in the power generation facility according to the present embodiment, when the temperature of seawater rises in summer or the like, control is appropriately performed so that the ratio of industrial water to seawater in the cooling water is increased, and the bearing cooling water Temperature rise is suppressed. For this reason, for example, even when the temperature of seawater rises greatly in summer or the like, the temperature of the bearing cooling water can be kept appropriate. Further, in the winter season or the like, when the temperature of the seawater falls below a predetermined value, the industrial water contained in the cooling water is appropriately controlled so as to be smaller than seawater, and the amount of industrial water intake is suppressed. In addition, as the industrial water, for example, by using the surplus industrial water used in the desulfurization apparatus, the temperature of the bearing cooling water can be adjusted while using the industrial water within the limits of the amount of water. Can be kept in.

  As described above, in the power generation facility of the present embodiment, when the industrial water surplus is a sufficient amount, for example, even when the seawater supply system is stopped for some reason, the industrial water is cooled as described above. The operation of the power generation facility can be continued using it as water. Moreover, since the salinity concentration of the cooling water is reduced by using industrial water, it is possible to prevent organisms from attaching to the equipment.

  By the way, the above description is for facilitating the understanding of the present invention, and does not limit the present invention. It goes without saying that the present invention can be changed and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

DESCRIPTION OF SYMBOLS 10 Condenser, 11 Bearing cooling water cooler, 12 Cooling object, 21 Circulating water pump, 22 Seawater booster pump, 23 Industrial water booster pump, 24 Bearing cooling water pump, 31 Intake port, 32 Outlet port, 41 Seawater flow rate control Valve, 42 Industrial water flow control valve, S1 Seawater temperature sensor, S2 Industrial water temperature sensor, S3 Bearing cooling water temperature sensor

Claims (3)

A condenser for condensing and condensing exhaust steam of a steam turbine that drives a generator by exchanging heat with seawater;
A bearing cooling water cooler that cools the bearing cooling water used for cooling the bearing of the steam turbine by heat exchange with the cooling water;
A cooling method for the bearing cooling water in a power generation facility comprising:
Using seawater and industrial water having a temperature lower than that of the seawater as the cooling water,
A cooling method for bearing cooling water, wherein a ratio of the sea water to the industrial water in the cooling water is controlled based on the temperature of the sea water, the temperature of the industrial water, and the temperature of the bearing cooling water. A cooling method for bearing cooling water according to claim 1,
A cooling method for bearing cooling water, which is controlled so that a ratio of industrial water to seawater in the cooling water increases when the temperature of the seawater rises. A cooling method for bearing cooling water according to claim 1 or 2,
A cooling method for bearing cooling water, wherein the cooling water is controlled so that a ratio of industrial water to seawater in the cooling water is small when a temperature of the seawater is a predetermined value or less.

Images