JPH10253271A - Coolant system of generation plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely eliminate the impurity of an oceanic life and the like when using, for example, sea water as a coolant by providing a heating fluid supply device for supplying a heated fluid at either one of the coolant side and or a side where the coolant is supplied of a plate-type heat exchanger. SOLUTION: For example, each one side of three plate-type heat exchangers 1a-1c has coolant supply pipes 2a-2c for guiding a coolant and a coolant return pipe for guiding the coolant after heat exchange to a drain pipe. When a microbe or oceanic life in the coolant are adhered in this king of coolant system, a heated fluid wire a relatively high temperature from a collection tank 7 being controlled to a proper temperature by an adjustment valve 12 being supplied to a side where the coolant is supplied of, for example, the heat exchanger 1c as a spare heats the heat-transfer element of the heat exchanger 1c and causes, for example, oceanic life being adhered to the coolant supply side to become extinct. Also, after, for example, the oceanic life of the heat exchanger 1c is eliminated, other heat exchangers 1a and 1b are also executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling water system of a power plant for recooling water to be cooled discharged from various heat exchangers using seawater, river water or the like as cooling water, and more particularly to seawater or the like. TECHNICAL FIELD The present invention relates to a cooling water system for a power plant that effectively removes impurities such as marine organisms contained in water.

[0002]

2. Description of the Related Art For example, a turbine plant is provided with a cooling water system for returning hot water to be cooled discharged from various heat exchangers as cooling water again. Among them, the high-temperature cooled water discharged from an oil cooler that cools oil for bearings of a steam turbine, a feed water pump drive turbine, a water feed pump, etc., or a hydrogen cooler that cools hydrogen circulating in the generator There is a cooler that collectively returns as cooling water.

This cooler is a multi-tube cylindrical heat exchanger using seawater or river water as cooling water.

[0004] In recent cooling water systems as well, there is a demand for a reduction in equipment and a high heat exchange rate, and the use of a plate heat exchanger has attracted attention in place of the conventionally used multi-tube cylindrical heat exchanger. It has come to be.

[0005] This plate type heat exchanger is formed by assembling plate-like or corrugated heat-transfer elements in a stack at equal intervals, and cooling water to one side with the heat-transfer element as a boundary. In addition, it is a counter-current type in which water to be cooled flows to the other side, and has the advantages of lower pressure loss, higher heat exchange rate and more compactness than multi-tube cylindrical type. Applied in.

[0006]

Although the plate heat exchanger has the above-mentioned advantages, it still has some problems, one of which is the clogging of the heat exchange passage. .

The plate heat exchanger is a plate-like or corrugated heat-transfer element, in which heat exchange passages for cooling water and high-temperature cooling water are alternately formed, but the passages are extremely narrow. Impurities easily adhere. For this reason, a strainer is provided at the inlet of the plate heat exchanger to remove inflow of microorganisms and marine organisms contained in seawater, etc.
Nevertheless, slime and the like may pass through the mesh and flow into the heat exchange passage, where they may propagate.

Means for preventing the inflow of microorganisms and marine organisms into the heat exchange passage include frequent disassembly and cleaning of the heat exchange passage, injection of chlorine into cooling water, or electrolysis of seawater. It is possible to inject sodium chlorite.

[0009] However, in the former case, the worker must inspect the heat exchange passages one by one, which is not suitable in consideration of the labor of the worker. Injecting itself into the marine pollution problem itself goes against the demands of the times and is undesirable.

As another means, it is conceivable to provide a jet washing device in the heat exchange passage or to provide a heating device for preheating the cooling water. Not suitable for conversion.

As described above, in the conventional cooling water system, even if a plate heat exchanger having excellent performance in terms of heat exchange is adopted, it is necessary to consider that seawater or the like is used as cooling water. There is a problem in the removal of marine life, which must be performed. For this reason, marine life removal measures have been taken by trial and error and are currently being sought.

The present invention has been made in view of such circumstances, and when seawater or the like is used as cooling water, a cooling water system of a power plant that can remove impurities such as marine organisms without pollution is provided. The purpose is to provide.

[0013]

In order to achieve the above object, a cooling water system for a power plant according to the present invention has a structure in which cooling water discharged from various heat exchangers is provided. In a cooling water system of a power plant including a plate heat exchanger, the heat exchange is performed by cooling water such as seawater to return the water to be cooled to cooling water and return to the original heat exchanger. A heating fluid supply device for supplying a heating fluid to at least one of the cooling water side and the cooling water side.

In order to achieve the above object, in the cooling water system of the power plant according to the present invention, as described in claim 2, the heating fluid of the heating / supplying device is provided with heat discharged from various heat exchangers. Either the fluid or the extracted steam of the turbine is selected.

In order to achieve the above object, the cooling water system of the power plant according to the present invention has a turbine selected from a main turbine and a feed water pump driven turbine. is there.

In order to achieve the above object, the cooling water system of the power plant according to the present invention is characterized in that the heat fluid discharged from various heat exchangers is heated by a feed water heater. It is characterized by the later water supply.

According to a fifth aspect of the present invention, there is provided a cooling water system for a power plant, wherein a heating fluid supply device includes a cooling water side of a plate heat exchanger and a cooling water side. It has a control valve for controlling the temperature of the heating fluid supplied to at least one of the water side.

According to a sixth aspect of the present invention, there is provided a cooling water system for a power plant, wherein a heating fluid supply device includes a recovery tank, a drain tank, a heater, a steam tank and a hot water supply system. At least one of the tanks is selected.

In order to achieve the above object, a cooling water system for a power plant according to the present invention, as described in claim 7, wherein the heating fluid supply device includes an auxiliary tank for further heating the heating fluid. It is.

In order to achieve the above object, in the cooling water system of the power plant according to the present invention, the plate heat exchanger is provided with a forward washing device and a backwashing device on the cooling water supply side. It is equipped with a device.

In order to achieve the above object, the cooling water system of the power plant according to the present invention is characterized in that the forward washing device and the backwash device are provided with a heating fluid supply for a plate heat exchanger. It comprises a connecting pipe for connecting the pipe and the cooling fluid return pipe to each other, and a cleaning valve interposed in the connecting pipe.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cooling water system for a power plant according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing a first embodiment of a cooling water system of a power plant according to the present invention.

The plate heat exchanger 1 according to the present embodiment
As for a, 1b, and 1c, any two are used for operation and one is used as a spare.

These plate heat exchangers 1a, 1b, 1
c is provided on one side with cooling water supply pipes 2, 2a, 2b, 2c for guiding cooling water such as seawater taken from an intake pipe through a booster pump 4, and cooling water after heat exchange. The cooling water return pipes 3, 3a, 3b, 3c for guiding to the water discharge pipe are provided.

The plate heat exchangers 1a, 1b, 1
c is a cooling water supply pipe 5, 5a, 5b, 5c for guiding a relatively high temperature of cooling water discharged from a cooler such as an oil cooler or a hydrogen cooler on each other side, and after heat exchange. And cooling water return pipes 6, 6a, 6b and 6c for returning the cooling water cooled to room temperature to the cooler again as cooling water.

Also, the cooling water return pipes 6, 6a, 6b, 6
c, each plate-type heat exchanger 1a,
Cooling water return branch pipes 8a, 8b, 8c for storing a part of the cooling water discharged from each of 1b, 1c in the recovery tank 7.
Is provided.

On the other hand, in the recovery tank 7, in addition to the above-described water to be cooled, a heat fluid such as a drain guided from another heat exchanger or a drain tank or the like is collected, and the stored water has a relatively high temperature. It is a thermal fluid.

The recovery tank 7 includes a hot fluid supply pipe 9 in which a pump 10, a stop valve 11, and a control valve 12 are sequentially provided. The configuration is provided with hot fluid supply branch pipes 13a, 13b, 13c connected to the respective 5a, 5b, 5c. In addition, each of the recovery tank 7 and the hot fluid supply mother pipe 9 supplies make-up water to each of the condenser and the condenser pipe as needed. Reference numerals 14a, 14b, 1
4c is a switching valve, respectively, these switching valves 14a,
Of 14b and 14c, a black portion indicates that the valve is normally closed, and a white portion indicates that the valve is open during use.

As shown in FIG. 2, the microorganisms and marine organisms contained in the cooling water often reach the breeding season when the water temperature is from 20 ° C. to 35 ° C. in the temperature range A of 20 ° C. to 35 ° C. It has been confirmed from interim measurement records.

For this reason, in the present embodiment, during the period from May to September, for example, heat is supplied from the hot fluid supply mother pipe 9 of the recovery tank 7 to the cooling water supply side of the plate heat exchanger 1c as a spare. When supplying a relatively high-temperature thermal fluid through the fluid supply branch pipe 13c, the plate-like or corrugated heat-transfer element of the plate-type heat exchanger 1c can be supplied by controlling it at an appropriate temperature with the control valve 12. It can be heated and kills marine organisms and the like that adhere to the side of the heat transfer element that does not supply the heat fluid, that is, the cooling water supply side. When the operation of removing the marine organisms from the plate heat exchanger 1c is completed, the operation is sequentially shifted to the other plate heat exchangers 1a and 1b.

As described above, in the present embodiment, when removing marine organisms and the like, the heat transfer element of the plate heat exchangers 1a, 1b, 1c is skillfully utilized by utilizing the relatively high temperature heat fluid in the recovery tank 7. Is heated from the cooling water supply side to kill marine organisms and the like attached to the cooling water supply side, so that impurities such as marine organisms can be reliably removed without pollution.

FIG. 3 is a schematic diagram showing a first embodiment of the first embodiment of the cooling water system of the power plant according to the present invention.

In this embodiment, a heat fluid supply source for killing and removing impurities such as marine organisms is provided on the cooling water supply pipe 2 side. Note that the constituent parts are given the same reference numerals as the constituent parts of the first embodiment. Further, the thermal fluid supply mother pipe 9
Is provided with a check valve 12a so that the cooling water does not flow back to the recovery tank 7.

In this embodiment, the plate type heat exchanger 1a,
Since the heating fluid is supplied directly to the cooling water passage side of each of the heat transfer elements 1b and 1c, the marine life attached to the cooling water passage side of the heat transfer element can be immediately killed, which is beneficial. In the description of the first embodiment, an example has been described in which the heat fluid is supplied to one of the cooling water supply side and the cooling water supply side of the heat transfer element. A more beneficial effect can be obtained by supplying a thermal fluid.

FIG. 4 is a schematic diagram showing a second embodiment of the cooling water system of the power plant according to the present invention. The first
The same components as those of the embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

In the present embodiment, an auxiliary tank 15 is provided in the hot fluid supply mother pipe 9, and the hot fluid supplied from the recovery tank 7 is heated. As a heating fluid source of the auxiliary tank 15, for example, one of a heater and high-pressure / high-temperature steam is used.

In general, the temperature and the flow rate of the heat fluid having a relatively high temperature collected in the recovery tank 7 vary depending on the operating conditions of the power plant such as partial load operation and full load operation. In addition, the death temperature of impurities such as marine organisms may be about 50 ° C. as shown in FIG.

In the present embodiment, an auxiliary tank 15 is provided in the hot fluid supply mother pipe 9 based on the above-described situation, and the hot fluid supplied from the recovery tank 7 is further heated.

Therefore, according to the present embodiment, the heat fluid can be reliably maintained at a high temperature regardless of the operation state of the power plant, and thus the plate heat exchangers 1a, 1b,
The heat transfer element can be heated from the cooling water supply side of 1c, and impurities such as marine organisms attached to the cooling water supply side of the heat transfer element can be reliably killed and removed.

FIG. 5 is a schematic diagram showing a first example of the second embodiment of the cooling water system of the power plant according to the present invention.

In this embodiment, as in the first embodiment of the first embodiment, a heat fluid supply source for killing and removing impurities such as marine organisms is provided on the cooling water supply pipe 2 side. . Note that the constituent parts are given the same reference numerals as those of the second embodiment shown in FIG.

In this embodiment, when the temperature of the hot fluid supplied from the recovery tank 7 is insufficient, the hot fluid is heated by the auxiliary tank 15, so that the plate heat exchangers 1a and 1a are heated.
Since the cooling water supply sides b and 1c are heated, impurities such as marine organisms attached to the cooling water supply side of each heat transfer element can be reliably killed and removed. In the description of the second embodiment, an example has been described in which the heat fluid is supplied to one of the cooling water supply side and the cooling water supply side of the heat transfer element. If a thermal fluid is supplied, more useful effects can be obtained.

FIG. 6 is a schematic diagram showing a third embodiment of the cooling water system of the power plant according to the present invention. The first
The same components as those of the embodiment are denoted by the same reference numerals.

This embodiment differs from the recovery tank 7 shown in the first embodiment in that a drain tank 16 having a large capacity is installed. In addition, the drain tank 16 requests the heat fluid for, for example, feed water after heating by a feed water heater (not shown). The feedwater temperature after heating of the feedwater heater is maintained at a higher temperature than the heat fluid of the first embodiment.

Therefore, according to the present embodiment, since a heat fluid which is higher in capacity and temperature than the first embodiment is secured, the supply of cooling water to the plate heat exchangers 1a, 1b, 1c is ensured. The heat transfer element can be heated from the side, and the impurities such as marine organisms attached to the cooling water supply side of the heat transfer element can be reliably killed and removed. Stable operation can be performed.

FIG. 7 is a schematic diagram showing a first example of the third embodiment of the cooling water system of the power plant according to the present invention. The same parts as those of the third embodiment are denoted by the same reference numerals.

In this embodiment, the plate-type heat exchangers 1a, 1b, 1c
When the cooling water is supplied to the cooling water supply side of each heat transfer element, the cooling water supply side of each heat transfer element can be freely washed and washed.

Each of the plate heat exchangers 1a, 1b, 1c is provided with a connecting pipe between the cooling water supply pipes 5, 5a, 5b, 5c and the cooling water return pipes 6, 6a, 6b, 6c. 1
9a, 19b, 19c, 20a, 20b, 20c, while each of the connecting pipes 19a, 19b,... Is provided with a washing valve 21a, 21b, 21c, 22a, 22b, 22c. .

For example, when the drain of the drain tank 16 is supplied to the plate heat exchanger 1a, the cleaning valve 21a of the connecting pipe 19a and the cleaning valve 22a of the connecting pipe 20a are opened to cool the heat transfer element. The water supply side can be backwashed, and if the cleaning valve 22a of the cooling water supply pipe 5a and the cleaning valve 22a of the cooling water return pipe 6a are opened, the cooling water supply side of the heat transfer element can be correctly cleaned. Can be washed.

As described above, in the present embodiment, since the cooling water side of the heat transfer element can be either flushed or backwashed, impurities such as marine organisms attached to the heat transfer element can be reliably killed. Can be removed. The above-mentioned connecting pipes 19a, 19b,...
The operation and effect of the third embodiment described above can also be obtained by applying to FIG.

FIG. 8 is a schematic diagram showing a fourth embodiment of the cooling water system of the power plant according to the present invention. The first
The same components as those of the embodiment are denoted by the same reference numerals.

In this embodiment, the plate heat exchanger 1a,
The heat fluid that kills and removes impurities such as marine organisms attached to the cooling water supply side of each of the heat transfer elements 1b and 1c is obtained as extracted steam of the steam turbine 17. The steam turbine 17 may be either a main turbine or a feedwater pump driving turbine. Further, the steam turbine 17 transfers the extracted steam to the plate heat exchangers 1a, 1a.
Prior to supply to each of the heat transfer elements b and 1c, a steam tank 18 for temporarily storing water is provided.

Since the extracted steam collected in the steam tank 18 is high-pressure and high-temperature steam, when the steam is supplied from the pump 10 to each of the heat transfer elements of the plate heat exchangers 1a, 1b and 1c, the control valve 12 is used. Is controlled to an appropriate pressure and appropriate temperature.

As described above, in the present embodiment, since the heat fluid for killing and removing impurities such as marine organisms is obtained from the extracted steam of the steam turbine 17, the plate heat exchanger 1
The heat transfer element can be heated from the cooling water supply side of a, 1b, and 1c, and impurities such as marine organisms attached to the cooling water supply side of the heat transfer element can be reliably killed and removed. In the present embodiment, the steam tank 18 for collecting the extracted steam of the steam turbine 17 is separately installed, so that the plate heat exchangers 1a, 1b, 1
Even if the cooling water leaks from each of the heat transfer elements c, it is possible to prevent a so-called water retention to the steam turbine 17.

In the case where the thermal fluid for killing and removing impurities such as marine organisms is required for the feed water pump driving turbine, either of the extracted steam and the exhaust steam may be used. In the case of exhaust steam, energy can be effectively used.

FIG. 9 is a schematic view showing a first embodiment of the fourth embodiment of the cooling water system of the power plant according to the present invention. The same parts as those of the fourth embodiment are denoted by the same reference numerals.

In the present embodiment, similarly to the fourth embodiment, a heat fluid is obtained from the extracted steam of the steam turbine 17 and the heat fluid is transferred to each heat transfer element of each of the plate heat exchangers 1a, 1b, 1c. Is supplied to the cooling water supply side.

As described above, in this embodiment, the heat fluid is obtained as the extracted steam of the steam turbine 17 and the extracted steam is supplied to the cooling water side of the heat transfer element. Impurities such as marine life can be reliably killed and removed.

In the present embodiment, the heat fluid is obtained as the extracted steam of the steam turbine 17. However, the invention is not limited to this, and the drainage of the auxiliary steam supplied to other devices in the power plant may be used. When the drain of the auxiliary steam is used for removing marine organisms and the like adhering to the respective heat transfer elements of each plate heat exchanger 1a, 1b, 1c, piping, valves, pumps, etc. become unnecessary, and equipment costs are reduced. Is beneficial. Further, in the description of the fourth embodiment, an example has been described in which the heat fluid is supplied to one of the cooling water supply side and the cooling water supply side of the heat transfer element. A more beneficial effect can be obtained by supplying a thermal fluid.

[0061]

As described above, the cooling water system of the power plant according to the present invention adheres to the plate heat exchanger.
Heated fluid is added to the grown marine organisms and other impurities to kill and remove them, so that chemicals such as chlorine are supplied to seawater, etc., as in the past, and pollution-free operation is performed without causing marine pollution. be able to.

Further, the cooling water system of the power plant according to the present invention supplies a heating fluid to at least one of the cooling water side and the cooling water side of the heat transfer element of the plate heat exchanger to supply marine organisms and the like. Since a means for killing marine organisms is taken, impurities such as marine organisms can be reliably removed.

In the cooling water system of the power plant according to the present invention, the cooling water side of the heat transfer element of the plate-type heat exchanger is provided with means for washing and backwashing the heat transfer element. There are no problems, and excellent effects such as stable operation of the plate heat exchanger can be achieved.

[Brief description of the drawings]

FIG. 1 is a first diagram of a cooling water system of a power plant according to the present invention.
The schematic diagram showing an embodiment.

FIG. 2 is a diagram illustrating the breeding time of impurities such as marine organisms.

FIG. 3 is a first diagram of a cooling water system of a power plant according to the present invention.
FIG. 2 is a schematic diagram showing a first example in the embodiment.

FIG. 4 shows a second example of the cooling water system of the power plant according to the present invention.
The schematic diagram showing an embodiment.

FIG. 5 shows a second example of the cooling water system of the power plant according to the present invention.
FIG. 2 is a schematic diagram showing a first example in the embodiment.

FIG. 6 shows a third example of the cooling water system of the power plant according to the present invention.
The schematic diagram showing an embodiment.

FIG. 7 is a third diagram of the cooling water system of the power plant according to the present invention.
FIG. 2 is a schematic diagram showing a first example in the embodiment.

FIG. 8 shows a fourth embodiment of the cooling water system of the power plant according to the present invention.
The schematic diagram showing an embodiment.

FIG. 9 is a fourth diagram showing the cooling water system of the power plant according to the present invention.
FIG. 2 is a schematic diagram showing a first example in the embodiment.

[Explanation of symbols]

1a, 1b, 1c Plate heat exchanger 2, 2a, 2b, 2c Cooling water supply pipe 3, 3a, 3b, 3c Cooling water return pipe 4 Booster pump 5, 5a, 5b, 5c Cooled water supply pipe 6, 6a , 6b, 6c Cooled water return pipe 7 Recovery tank 8a, 8b, 8c Cooled fluid return branch pipe 9 Heat fluid supply mother pipe 10 Pump 11 Stop valve 12 Control valve 12a Check valve 13a, 13b, 13c Heat fluid supply branch Pipe 14a, 14b, 14c Switching valve 15 Auxiliary tank 16 Drain tank 17 Steam turbine 18 Steam tank 19a, 19b, 19c, 20a, 20b, 20c Communication pipe 21a, 21b, 21c, 22a, 22b, 22c Washing valve

Claims (9)

[Claims] 1. A plate heat exchanger in which water to be cooled discharged from various heat exchangers is heat-exchanged with cooling water such as seawater to convert the water to be cooled into cooling water and return to the original heat exchanger. In a cooling water system of a power plant having: a heating fluid supply device for supplying a heating fluid to at least one of a cooling water side and a cooled water side of the plate heat exchanger. Power plant cooling water system. 2. The power plant according to claim 1, wherein the heating fluid of the heating supply device is selected from a hot fluid discharged from various heat exchangers and a steam extracted from the turbine. Cooling water system. 3. The cooling water system for a power plant according to claim 2, wherein the turbine is selected from one of a main turbine and a feed water pump driven turbine. 4. The cooling water system for a power plant according to claim 2, wherein the heat fluid discharged from the various heat exchangers is feedwater after heating of a feedwater heater. 5. The heating fluid supply device includes a control valve for controlling the temperature of the heating fluid supplied to at least one of the cooling water side and the cooling water side of the plate heat exchanger. A cooling water system for the power plant according to claim 1. 6. The cooling of a power plant according to claim 1, wherein the heating fluid supply device is selected from at least one of a recovery tank, a drain tank, a heater, a steam tank, and a hot water tank. Water system. 7. The cooling water system of a power plant according to claim 1, wherein the heating fluid supply device includes an auxiliary tank for further heating the heating fluid. 8. The cooling water system for a power plant according to claim 1, wherein the plate heat exchanger includes a forward washing device and a backwash device on a cooling water supply side. 9. A forward washing apparatus and a backwash apparatus each include a communication pipe connecting a heating fluid supply pipe and a cooling fluid return pipe of a plate heat exchanger to each other, and a cleaning valve interposed in the communication pipe. 9. The cooling water system for a power plant according to claim 8, wherein