JPH09257987A - Cooling system facility for auxiliary machine of plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make constant a cooling water supply main pipe even if the quantity of cooling water is less, by connecting an escape pipe to the inlet pipe of cooling water pump from the discharge pipe of the pump, and arranging at the escape pipe a pressure regulating valve opened and closed according to the pressure of pressure detector disposed at the main pipe. SOLUTION: At a cooling water supply main pipe 27 a pressure detector 43 is disposed, and an escape pipe 44 is connected to the upstream cooling water pump inlet pipe 40 of a pump inlet valve 41 from the downstream cooling pump discharge pipe 22 of a discharge valve 24. At the pipe 44 a pressure regulating valve 45 opened and closed according to the pressure of main pipe 27 detected by the detector 43 is arranged. The detector 43 performs the setting so that the cooling water quantity circulated at the time of rated operation condition of a plant becomes the maximum level while the pressure of the main pipe 27 becomes the minimum level and if the pressure exceeds the level the valve 45 is opened while the valve 45 is closed if the pressure is not more than the level. Accordingly the pressure of a cooling water returning main pipe 39 is maintained constant by a surge tank 42 and the difference in pressure at the inlet and outlet of load is maintained constant.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an auxiliary cooling system facility for a plant such as a nuclear power plant.

[0002]

2. Description of the Related Art FIG. 4 is a system diagram showing an auxiliary cooling system facility of a conventional plant. As shown in FIG. 4, the cooling water whose pressure has been increased by the cooling water pump 1 passes through the discharge check valve 2 and the discharge valve 3, a part of which is cooled by the seawater heat exchanger 4, and then the temperature of the mother pipe is adjusted. It is mixed at a set temperature through valves 5 and 5 and sent to a cooling water supply mother pipe 6. After that, the flow rate of one of the load cooling water is adjusted by the manual throttle valve 7, and passes through the cooler 8 for removing the heat generated from each device, the flow meter 9, and the cooler outlet valve 10 to the cooling water return mother pipe 15. Be guided.

The flow rate of the other load cooling water is adjusted by the temperature adjusting valve 11 controlled by the temperature detector 14 so that the temperature of the system 13 on the cooled side becomes constant, and the cooler inlet valve 12 , A cooler 8 for removing heat generated from each device,
It is guided to the cooling water return mother pipe 15 via the cooler outlet valve 10. The cooling water that has passed through the cooling water return mother pipe 15 returns to the cooling water pump 1 through the pump inlet valve 17 to form a closed loop. An atmospheric pressure surge tank 16 is connected to the cooling water return mother pipe 15, and the pressure of the cooling water return mother pipe 15 is kept constant by this surge tank 16.

[0004]

By the way, as described above, the auxiliary cooling water system is provided with the temperature control valve 11 for adjusting the amount of cooling water in order to keep the temperature of the system 13 on the cooling side constant. Although the system 13 on the cooled side, which is attached, changes the required amount of cooling water depending on the operating state of the nuclear power plant, the temperature control valve 11 opens or closes or has an intermediate opening. As a result, the amount of cooling water circulating in the auxiliary equipment cooling water system changes.

Here, the cooling water pump 1 is generally characterized in that the pump head decreases when the discharge flow rate increases, and conversely the pump head increases when the discharge flow rate decreases. Therefore, the pump head also changes due to the change in the amount of cooling water circulating in the auxiliary cooling water system, which in turn changes the pressure of the cooling water system itself.

On the other hand, the manual throttle valve 7 side is fixed so as to flow the required amount of cooling water during the rated operation of the nuclear power plant, that is, when the cooling water circulation flow rate is maximum and the pressure in the auxiliary cooling water system is minimum. Therefore, when the plant is stopped or the plant is started, the amount of circulating cooling water is small, so the pressure in the auxiliary cooling water system becomes high, and the differential pressure between the cooling water supply mother pipe 6 and the cooling water return mother pipe 15 becomes large. It becomes large and the flow rate exceeds the regulation. This is not preferable because it may damage the cooling pipe 18 in the cooler 8 or damage the meter beyond the measurement range of the flow meter 9.

The present invention has been made in consideration of the above-mentioned circumstances, and is a plant capable of ensuring a constant flow rate without causing an excessive flow rate in the cooling pipe under the influence of a pressure change caused by a change in the circulating flow rate of the cooling water. It is an object of the present invention to provide auxiliary equipment cooling system equipment of.

[0008]

In order to solve the above-mentioned problems, according to claim 1 of the present invention, a cooling water pump discharge pipe is connected to a cooling water pump, and a cooling water supply mother is connected to this cooling water pump discharge pipe. A pipe is connected to this cooling water supply mother pipe, and a cooling water return mother pipe is connected to the cooling water supply mother pipe via a cooling pipe in which a cooler for removing heat generated from each device is arranged. In a plant auxiliary equipment cooling system facility in which the cooling water pump is connected via a water pump inlet pipe to form a closed loop, a pressure detector is arranged in the cooling water supply mother pipe, and the cooling water pump discharge pipe is provided. A relief pipe is connected to the cooling water pump inlet pipe, and the relief pipe is provided with a pressure control valve that opens and closes based on the pressure of the cooling water supply mother pipe detected by the pressure detector. To do.

According to a second aspect of the present invention, a cooling water pump discharge pipe is connected to the cooling water pump, a cooling water supply mother pipe is connected to the cooling water pump discharge pipe, and heat generated from each device is generated in the cooling water supply mother pipe. A cooling water return mother pipe is connected through a cooling pipe provided with a cooler for removing the cooling water, and the cooling water pump is connected to this cooling water return mother pipe through a cooling water pump inlet pipe to form a closed loop. In the auxiliary equipment cooling system equipment of the plant, a flow rate detecting means for detecting the amount of cooling water flowing in the cooling pipe is provided, and a relief pipe is connected from the cooling water pump discharge pipe to the cooling water pump inlet pipe. A flow rate control valve that opens and closes based on the amount of cooling water flowing in the cooling pipe detected by the flow rate detecting means is provided.

According to a third aspect of the present invention, a cooling water pump discharge pipe is connected to the cooling water pump, a cooling water supply mother pipe is connected to the cooling water pump discharge pipe, and heat generated from each device is generated in the cooling water supply mother pipe. A cooling water return mother pipe is connected through a cooling pipe provided with a cooler for removing the cooling water, and the cooling water pump is connected to this cooling water return mother pipe through a cooling water pump inlet pipe to form a closed loop. In the auxiliary equipment cooling system equipment of the plant, a flow rate detecting means for detecting the amount of cooling water flowing through the cooling pipe is provided, and a flow rate control valve for controlling the amount of cooling water flowing through the cooling pipe based on the detection result of the flow rate detecting means is provided. It is characterized in that it is arranged in the cooling pipe.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system diagram showing a first embodiment of an auxiliary cooling system facility for a plant according to the present invention. In this embodiment, an example applied to a nuclear power plant is shown as a plant. As shown in FIG. 1, a cooling water pump discharge pipe 22 is connected to the cooling water pump 21, and in this cooling water pump discharge pipe 22, a discharge check valve 23, a discharge valve 24, and a discharge valve 24 are provided on the downstream side of the flow of the cooling water. A seawater heat exchanger 25 and a mother pipe temperature control valve 26 are sequentially arranged.

The cooling water pump discharge pipe 22 is connected to a cooling water supply mother pipe 27, and cooling pipes 28 and 29 are connected to the cooling water supply mother pipe 27. This cooling pipe 2
8, a manual throttle valve 30 for adjusting the flow rate on the downstream side, a cooler 31 for removing heat generated from each device, a flow meter 32,
And the cooler outlet valve 33 is sequentially arranged.

On the other hand, in the cooling pipe 29, a temperature control valve 34, a cooler inlet valve 35, a cooler 31 for removing heat generated from each device, and a cooler outlet valve 36 are sequentially arranged on the downstream side, The temperature control valve 34 is controlled by the temperature detector 38 so that the temperature of the system 37 on the cooling side becomes constant, and the flow rate thereof is adjusted.

The cooling pipes 28 and 29 are cooling water return mother pipes 39.
The cooling water return mother pipe 39 is connected to the cooling water pump 21 via the cooling water pump inlet pipe 40, and the cooling water pump inlet pipe 40 is provided with a pump inlet valve 41. An atmospheric pressure surge tank 42 is connected to the cooling water return mother pipe 39, and the pressure of the cooling water return mother pipe 39 is kept constant by this surge tank 42.

Therefore, in this embodiment, the cooling water pump 21 is passed through the cooling water pump discharge pipe 22, the cooling water supply mother pipe 27, the cooling pipes 28 and 29, the cooling water return mother pipe 39, and the cooling water pump inlet pipe 40. A closed loop returning to the cooling water pump 21 is configured.

By the way, in the present embodiment, the pressure detector 43 is arranged in the cooling water supply mother pipe 27, and the cooling water pump discharge pipe 22 on the downstream side of the discharge valve 24 is connected to the pump inlet valve 4.
1 escape pipe 4 to the cooling water pump inlet pipe 40 on the upstream side
4 is connected to the relief pipe 44, and the pressure detector 4
A pressure control valve 45 that opens and closes based on the pressure of the cooling water supply mother pipe 27 detected by No. 3 is provided.

An electropneumatic converter (not shown) is installed between the pressure detector 43 and the pressure control valve 45, and a signal detected by the pressure detector 43 is output by the electropneumatic converter as an air output. And the opening of the pressure control valve 45 is adjusted.

Next, the operation of this embodiment will be described.

The cooling water boosted by the cooling water pump 21 passes through the discharge check valve 23 and the discharge valve 24, a part of which is cooled by the seawater heat exchanger 25, and then the mother pipe temperature control valve 26. The mixture is mixed at a preset temperature and sent to the cooling water supply mother pipe 27. After that, the flow rate of the one load cooling water is adjusted by the manual throttle valve 30, and the cooler 31, the flow meter 32,
And it is led to the cooling water return mother pipe 39 through the cooler outlet valve 33.

The flow rate of the other load cooling water is adjusted by the temperature adjusting valve 34 controlled by the temperature detector 38 so that the temperature of the system 37 on the cooled side becomes constant, and the cooler inlet valve 35. , The cooling device 31, and the cooling device outlet valve 36, and is guided to the cooling water return mother pipe 39. The cooling water that has passed through the cooling water return mother pipe 39 returns to the cooling water pump 21 through the pump inlet valve 41.

By the way, in the present embodiment, the pressure detector 43 is set at the rated operation of the nuclear power plant, that is, when the circulating water amount is maximum and the pressure of the cooling water supply pipe 27 is the lowest. The pressure control valve 45 opens when this pressure is exceeded, and conversely, the pressure control valve 45 is closed at or below this pressure or at the same pressure.

Since the circulating flow rate of the cooling water changes depending on the condition of the plant, the circulating flow rate is small when the plant is stopped or when the plant is started. , Cooling water supply pipe 2
The pressure detector 43 installed at 7 detects that the pressure reaches or exceeds the set value and opens the pressure control valve 45 to increase the pump discharge flow rate, and the pump head decreases due to the pump characteristics.

As a result, the pressure in the cooling water supply mother pipe 27 does not rise, and the pressure in the cooling water return mother pipe 39 is kept constant by the surge tank 42 open to the atmosphere, so that the differential pressure at the load inlet and outlet is kept constant. . As a result, overflow does not occur, and the cooling pipe (tube) 31a and the flow meter 32 in the cooler 31 can be maintained soundly.

FIG. 2 is a system diagram showing a second embodiment of auxiliary equipment cooling system equipment for a plant according to the present invention. The same parts as those in the first embodiment will be described with the same reference numerals. The same applies to the following embodiments.

In the second embodiment, in addition to the auxiliary cooling system equipment of a general nuclear power plant, a flow rate transmitter 46 as a flow rate detecting means for detecting the amount of cooling water flowing through the cooling pipeline 28 is provided in the cooling pipeline 28. Provided and discharge valve 24
An escape pipe 44 is connected from the cooling water pump discharge pipe 22 on the downstream side of the pump to the cooling water pump inlet pipe 40 on the upstream side of the pump inlet valve 41. The escape pipe 44 has the cooling pipe 28 detected by the flow rate transmitter 46. A flow rate control valve 47 that opens and closes based on the amount of cooling water flowing through is disposed. The flow rate control valve 47 is opened when the flow rate set by the flow rate transmitter 46 is exceeded.

Next, the operation of this embodiment will be described.

Since the circulating flow rate of the cooling water changes depending on the state of the nuclear power plant, the circulating flow rate is small when the plant is stopped or the plant is started. Get higher As a result, the pressure difference with the cooling water return mother pipe 39 becomes large. As a result, an excessive flow rate is generated, but when the flow rate set by the flow rate transmitter 46 attached to the cooling pipe 28 is exceeded, the flow rate control valve 47 opens and the circulating flow rate of the cooling water system increases, so that the pump head is lowered. Inevitably, the pressure of the cooling water supply mother pipe 27 is also reduced to reduce the differential pressure, and it is possible to prevent overflow.

The flow rate of the cooling water between the cooling pipes 28 and 29 flows in balance due to the differential pressure between the cooling water supply mother pipe 27 and the cooling water return mother pipe 39, so that either one of the cooling pipes It is possible to prevent overflow of the remaining cooling pipes only by monitoring the overflow of. Also, other configurations,
The operation and effect are similar to those of the first embodiment, and therefore the description thereof will be omitted.

FIG. 3 is a system diagram showing a third embodiment of auxiliary equipment cooling system equipment for a plant according to the present invention. In the third embodiment, instead of the manual throttle valve 30 in the first embodiment, a flow rate adjusting valve 48 controlled by a flow rate transmitter 46 as a flow rate detecting means is attached.

That is, in the third embodiment, the cooling pipe 2
8, a flow rate transmitter 46 for detecting the amount of cooling water flowing through the cooling pipe 28 is provided, and a flow rate control valve 48 for controlling the amount of cooling water flowing through the cooling pipe 28 based on the detection result of the flow rate transmitter 46 is provided in the cooling pipe. 28.

Next, the operation of this embodiment will be described.

As described above, since the circulating flow rate of cooling water changes depending on the state of the nuclear power plant, the circulating flow rate is small when the plant is stopped or when the plant is started. The pressure in the tube 27 also increases. As a result, the pressure difference between the cooling water return mother pipe 39 and the overflow rate increases, but the flow rate control valve 48 is controlled so that the flow rate is set by the flow rate transmitter 46, so that the overflow rate may occur. There is no. The rest of the configuration, action, and effect are the same as those of the first embodiment, so the description thereof is omitted.

In each of the above-mentioned embodiments, an example in which the present invention is applied to a nuclear power plant has been described, but it is also applicable to other plants such as a thermal power plant.

[0035]

As described above, according to the first aspect of the present invention.
According to the above, a pressure detector is arranged in the cooling water supply mother pipe, a relief pipe is connected from the cooling water pump discharge pipe to the cooling water pump inlet pipe, and the cooling water detected by the pressure detector is connected to this relief pipe. By arranging a pressure control valve that opens and closes based on the pressure of the supply mother pipe, the pressure of the cooling water supply mother pipe is kept constant even when the amount of cooling water circulated when the plant is stopped or started is small. By adjusting, the excessive flow rate can be prevented, the tubes of the cooler and the flow meter arranged in the cooling pipe can be maintained soundly, and it can contribute greatly to the stable operation of the plant.

According to the second aspect, a flow rate detecting means for detecting the amount of cooling water flowing through the cooling pipe is provided, and the escape pipe is connected from the cooling water pump discharge pipe to the cooling water pump inlet pipe,
The same effect as in claim 1 can be obtained by disposing a flow rate control valve that opens and closes on the relief pipe according to the amount of cooling water flowing through the cooling pipe detected by the flow rate detecting means.

According to the third aspect of the present invention, the flow rate detecting means for detecting the amount of cooling water flowing through the cooling pipe is provided, and the flow rate adjusting valve for controlling the amount of cooling water flowing through the cooling pipe is provided based on the detection result of the flow rate detecting means. By arranging in the above, the same effect as in claim 1 can be obtained.

[Brief description of drawings]

FIG. 1 is a system diagram showing a first embodiment of an auxiliary cooling system facility for a plant according to the present invention.

FIG. 2 is a system diagram showing a second embodiment of an auxiliary cooling system facility for a plant according to the present invention.

FIG. 3 is a system diagram showing a third embodiment of auxiliary equipment cooling system equipment for a plant according to the present invention.

FIG. 4 is a system diagram showing an auxiliary cooling system facility of a conventional plant.

[Explanation of symbols]

 21 cooling water pump 22 cooling water pump discharge pipe 23 discharge check valve 24 discharge valve 25 seawater heat exchanger 26 mother pipe temperature control valve 27 cooling water supply mother pipe 28 cooling pipe 29 cooling pipe 30 manual throttle valve 31 cooler 31a cooling Pipe 32 Flowmeter 33 Cooler outlet valve 34 Temperature control valve 35 Cooler inlet valve 36 Cooler outlet valve 37 Cooled side system 38 Temperature detector 39 Cooling water return mother pipe 40 Cooling water pump inlet pipe 41 Pump inlet valve 42 Surge Tank 43 Pressure Detector 44 Relief Pipe 45 Pressure Control Valve 46 Flow Transmitter (Flow Detection Unit) 47 Flow Control Valve 48 Flow Control Valve

Claims (3)

[Claims] 1. A cooling water pump discharge pipe is connected to a cooling water pump, a cooling water supply mother pipe is connected to this cooling water pump discharge pipe, and heat generated from each device is removed from this cooling water supply mother pipe. A cooling water return mother pipe is connected through a cooling pipe provided with a cooler, and the cooling water pump is connected to this cooling water return mother pipe through a cooling water pump inlet pipe to form a closed loop plant. In the auxiliary equipment cooling system facility, a pressure detector is arranged in the cooling water supply mother pipe, a relief pipe is connected from the cooling water pump discharge pipe to the cooling water pump inlet pipe, and the pressure detection is performed in the relief pipe. An auxiliary machine cooling system facility for a plant, comprising a pressure control valve that opens and closes based on the pressure of the cooling water supply mother pipe detected by a vessel. 2. A cooling water pump discharge pipe is connected to the cooling water pump, a cooling water supply mother pipe is connected to this cooling water pump discharge pipe, and heat generated from each device is removed from this cooling water supply mother pipe. A cooling water return mother pipe is connected through a cooling pipe provided with a cooler, and the cooling water pump is connected to this cooling water return mother pipe through a cooling water pump inlet pipe to form a closed loop plant. In the auxiliary equipment cooling system equipment, a flow rate detecting means for detecting the amount of cooling water flowing in the cooling pipe is provided, and a relief pipe is connected from the cooling water pump discharge pipe to the cooling water pump inlet pipe, and this relief pipe has the flow rate. An auxiliary equipment cooling system facility for a plant, characterized in that a flow control valve that opens and closes based on the amount of cooling water flowing through the cooling pipe detected by the detecting means is provided. 3. A cooling water pump discharge pipe is connected to the cooling water pump, a cooling water supply mother pipe is connected to this cooling water pump discharge pipe, and heat generated from each device is removed to this cooling water supply mother pipe. A cooling water return mother pipe is connected through a cooling pipe provided with a cooler, and the cooling water pump is connected to this cooling water return mother pipe through a cooling water pump inlet pipe to form a closed loop plant. In the auxiliary equipment cooling system facility, a flow rate detecting means for detecting the amount of cooling water flowing through the cooling pipe is provided, and a flow rate control valve for controlling the amount of cooling water flowing through the cooling pipe based on the detection result of the flow rate detecting means is provided in the cooling pipe. An auxiliary cooling system facility for a plant, which is characterized by being installed in.