Nuclear power plant conventional island closed-loop cooling water system

Abstract

The utility model discloses a nuclear power plant conventional island closed-loop cooling water system which comprises a high-level water tank, a connecting pipeline, a first branch pipeline, a second branch pipeline, a third branch pipeline, a first mother pipeline, a fourth branch pipeline, a fifth branch pipeline and a second mother pipeline. The high-level water tank is connected with the conventional island demineralized water distribution system and the connecting pipeline; a first water pump, a first isolating valve and a second isolating valve are arranged on the first branch pipeline; a second water pump, a third isolating valve and a fourth isolating valve are arranged on the second branch pipeline; a third water pump, a fifth isolating valve and a sixth isolating valve are arranged on the third branch pipeline; a first heat exchanger is arranged on the fourth branch pipeline; a second heat exchanger is arranged on the fifth branch pipeline; and the second mother pipeline is provided with a conventional island cooler. The closed-loop cooling water system for the conventional island of the nuclear power plant can be used for conducting heat and cooling each user cooler (or each user heat exchanger) of the conventional island of the nuclear power plant, and can ensure safe and stable operation of each user cooler of the conventional island of the nuclear power plant.

Description

Technical Field

[0001] The utility model relates to the technical field of nuclear power, in particular to a conventional island closed-circuit cooling water system of a nuclear power plant. Background Art

[0002] The conventional island system of a nuclear power plant is equipped with a variety of equipment, such as air compressors, drain pumps, feed water deaerators, etc. These devices will generate heat during operation, and the heat needs to be discharged in time to ensure that these devices can operate normally and will not cause shutdowns or damage due to excessive heat. In order to ensure the operation of the entire conventional island system, it is necessary to develop a suitable cooling system to conduct heat and cool the equipment. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a conventional island closed-circuit cooling water system for a nuclear power plant.

[0004] The utility model solves the technical problem by adopting the following technical solution: constructing a conventional island closed-circuit cooling water system of a nuclear power plant, including a high-level water tank, a connecting pipeline, a first branch pipeline, a second branch pipeline, a third branch pipeline, a first main pipeline, a fourth branch pipeline, a fifth branch pipeline, and a second main pipeline;

[0005] One end of the high-level water tank is used to connect to a conventional island desalted water distribution system, and the other end of the high-level water tank is connected to the first end of the connecting pipeline;

[0006] The first branch pipeline, the second branch pipeline and the third branch pipeline are arranged in parallel, and the first ends after being connected in parallel are connected to the second end of the connecting pipeline, and the second ends after being connected in parallel are connected to the first end of the first main pipeline;

[0007] The first branch pipeline is provided with a first water pump, and a first isolation valve and a second isolation valve are respectively provided upstream and downstream of the first water pump; the second branch pipeline is provided with a second water pump, and a third isolation valve and a fourth isolation valve are respectively provided upstream and downstream of the second water pump; the third branch pipeline is provided with a third water pump, and a fifth isolation valve and a sixth isolation valve are respectively provided upstream and downstream of the third water pump;

[0008] The fourth branch pipeline and the fifth branch pipeline are arranged in parallel, and the first end after parallel connection is connected to the second end of the first main pipeline, and the second end after parallel connection of the fourth branch pipeline and the fifth branch pipeline is connected to the first end of the second main pipeline; the fourth branch pipeline is provided with a first heat exchanger, the first heat exchanger has a first heat exchange pipeline and a second heat exchange pipeline, the first heat exchange pipeline is connected to the first branch pipeline, the second heat exchange pipeline is connected to the first cooling water source, and the fourth branch pipeline is respectively provided with a seventh isolation valve and an eighth isolation valve at the upstream and downstream of the first heat exchanger; the fifth branch pipeline is provided with a second heat exchanger, the second heat exchanger has a third heat exchange pipeline and a fourth heat exchange pipeline, the first heat exchange pipeline is connected to the fifth branch pipeline, the fourth heat exchange pipeline is connected to the second cooling water source, and the fifth branch pipeline is respectively provided with a ninth isolation valve and a tenth isolation valve at the upstream and downstream of the second heat exchanger;

[0009] The second end of the second mother pipeline is connected to the connecting pipeline, and the second mother pipeline is provided with a conventional island cooler.

[0010] In some embodiments, a float valve is provided in the high-level water tank.

[0011] In some embodiments, a first check valve is provided on a section of the first branch line between the first water pump and the second isolation valve;

[0012] A second check valve is provided on a section of the second branch pipeline between the second water pump and the fourth isolation valve;

[0013] A third check valve is provided on a section of the third branch pipeline between the third water pump and the sixth isolation valve.

[0014] In some embodiments, the first water pump, the second water pump, and the third water pump are all horizontal centrifugal pumps.

[0015] In some embodiments, the first heat exchanger and the second heat exchanger are both tubular heat exchangers.

[0016] In some embodiments, the inlet end of the second heat exchange pipe is connected to the first water inlet pipeline, the outlet end of the second heat exchange pipe is connected to the first water outlet pipeline, the first water inlet pipeline is provided with a first valve, and the first water outlet pipeline is provided with a second valve.

[0017] In some embodiments, the inlet end of the fourth heat exchange pipe is connected to the second water inlet pipeline, the outlet end of the fourth heat exchange pipe is connected to the second water outlet pipeline, the second water inlet pipeline is provided with a third valve, and the second water outlet pipeline is provided with a fourth valve.

[0018] In some embodiments, the conventional island closed-circuit cooling water system of the nuclear power plant further includes a bypass pipeline, and two ends of the bypass pipeline are respectively connected in parallel to two ends of the second mother pipeline;

[0019] The bypass pipeline is provided with a bypass valve.

[0020] In some embodiments, a temperature sensor is disposed on the first bus line and / or the second bus line.

[0021] In some embodiments, the high-level water tank is provided with a liquid level gauge.

[0022] The implementation of the utility model has the following beneficial effects: the closed-circuit cooling water system of the conventional island of a nuclear power plant can be used to conduct heat and cool the coolers (or heat exchangers) of each user in the conventional island of the nuclear power plant, thereby ensuring the safe and stable operation of the coolers of each user in the conventional island of the nuclear power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solution of the utility model, the utility model will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the utility model, and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0024] Figure 1 It is a schematic diagram of a conventional island closed-circuit cooling water system of a nuclear power plant in some embodiments of the present invention. DETAILED DESCRIPTION

[0025] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0026] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0027] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details that hinder the description of the present invention.

[0028] See also Figure 1 The utility model shows a conventional island closed-circuit cooling water system of a nuclear power plant, including a high-level water tank 10, a connecting pipeline 20, a first branch pipeline 30, a second branch pipeline 40, a third branch pipeline 50, a first main pipeline 60, a fourth branch pipeline 70, a fifth branch pipeline 80, and a second main pipeline 90.

[0029] One end of the high-level water tank 10 is used to connect to a conventional island demineralized water distribution system, and the other end of the high-level water tank 10 is connected to a first end of a connecting pipeline 20 .

[0030] The first branch pipeline 30, the second branch pipeline 40 and the third branch pipeline 50 are arranged in parallel, and the first ends after parallel connection are connected to the second end of the connecting pipeline 20, and the second ends after parallel connection of the first branch pipeline 30, the second branch pipeline 40 and the third branch pipeline 50 are connected to the first end of the first main pipeline 60.

[0031] The first branch pipeline 30 is provided with a first water pump 31, and a first isolation valve 32 and a second isolation valve 33 are respectively provided upstream and downstream of the first water pump 31; the second branch pipeline 40 is provided with a second water pump 41, and a third isolation valve 42 and a fourth isolation valve 43 are respectively provided upstream and downstream of the second water pump 41; the third branch pipeline 50 is provided with a third water pump 51, and a fifth isolation valve 52 and a sixth isolation valve 53 are respectively provided upstream and downstream of the third water pump 51.

[0032] The fourth branch pipeline 70 and the fifth branch pipeline 80 are arranged in parallel, and the first end after parallel connection is connected to the second end of the first mother pipeline 60, and the second end after parallel connection of the fourth branch pipeline 70 and the fifth branch pipeline 80 is connected to the first end of the second mother pipeline 90; the fourth branch pipeline 70 is provided with a first heat exchanger 71, the first heat exchanger 71 has a first heat exchange pipeline and a second heat exchange pipeline, the first heat exchange pipeline is connected to the first branch pipeline 30, the second heat exchange pipeline is connected to the first cooling water source, and the fourth branch pipeline 70 is located at the upstream and downstream of the first heat exchanger 71 and is respectively provided with a seventh isolation valve 72 and an eighth isolation valve 73; the fifth branch pipeline 80 is provided with a second heat exchanger 81, the second heat exchanger 81 has a third heat exchange pipeline and a fourth heat exchange pipeline, the third heat exchange pipeline is connected to the fifth branch pipeline 80, the fourth heat exchange pipeline is connected to the second cooling water source, and the fifth branch pipeline 80 is located at the upstream and downstream of the second heat exchanger 81 and is respectively provided with a ninth isolation valve 82 and a tenth isolation valve 83.

[0033] The second end of the second mother pipeline 90 is connected to the connecting pipeline 20. The second mother pipeline 90 is provided with a conventional island cooler. The conventional island cooler here includes various types of conventional island coolers that need to be cooled, such as air compressors, drain pumps, sampling room coolers, auxiliary water tank coolers, etc. that need to be cooled.

[0034] Among them, the conventional island closed-loop cooling water system of the nuclear power plant has three operating modes, including "single cooling mode", "dual cooling mode" and "mixed cooling mode".

[0035] "Single cooling mode" means: only one heat exchanger is put into operation, for example (1) the first heat exchanger 71 is put into operation, at which time the seventh isolation valve 72 and the eighth isolation valve 73 are opened, and the second heat exchange pipeline is connected to the first cooling water source. The second heat exchanger 81 is not put into operation, at which time the ninth isolation valve 82 and the tenth isolation valve 83 are closed. Or (2) the first heat exchanger 71 is not put into operation, at which time the seventh isolation valve 72 and the eighth isolation valve 73 are closed. The second heat exchanger 81 is put into operation, at which time the ninth isolation valve 82 and the tenth isolation valve 83 are opened.

[0036] The "dual cooling mode" is: both heat exchangers are put into operation, for example, the first heat exchanger 71 is put into operation, at which time the seventh isolation valve 72 and the eighth isolation valve 73 are opened, and the second heat exchange pipeline is connected to the first cooling water source. The second heat exchanger 81 is put into operation, at which time the ninth isolation valve 82 and the tenth isolation valve 83 are opened, and the fourth heat exchange pipeline is connected to the second cooling water source.

[0037] "Mixed cooling mode" means: one heat exchanger is put into operation and the load side of another heat exchanger is put into operation, and the cooling water source side is closed. For example, (1) the first heat exchanger 71 is put into operation, at which time the seventh isolation valve 72 and the eighth isolation valve 73 are opened, and the second heat exchange pipe is connected to the first cooling water source. The second heat exchanger 81 is put into operation, at which time the ninth isolation valve 82 and the tenth isolation valve 83 are opened, and the fourth heat exchange pipe is not connected to the second cooling water source. (2) The first heat exchanger 71 is put into operation, at which time the seventh isolation valve 72 and the eighth isolation valve 73 are opened, and the second heat exchange pipe is not connected to the first cooling water source. The second heat exchanger 81 is put into operation, at which time the ninth isolation valve 82 and the tenth isolation valve 83 are opened, and the fourth heat exchange pipe is connected to the second cooling water source.

[0038] When the unit does not need the conventional island closed-circuit cooling water system to operate at a large flow rate, the "single cooling mode" can be used. When the unit needs the conventional island closed-circuit cooling water system to operate at a large flow rate, the "dual cooling mode" can be used. When the unit needs the conventional island closed-circuit cooling water system to operate at a large flow rate (with public load), and the superimposed seawater temperature is too low (such as winter conditions), the "mixed cooling mode" can be used, which can avoid the low flow alarm of each cooler in the conventional island and achieve the purpose of heat exchange, and operate well.

[0039] In some embodiments, the high-level water tank 10 is a high-level water tank with a working volume of 2.2 m 3 Rectangular water tank with a working volume of 1.62m 3 , the maximum water supply flow is 3.6m 3 / h. Its length, width and height are 2495mm, 920mm and 1190mm respectively. The high-level water tank 10 may be provided with a liquid level gauge for monitoring the liquid level. The liquid level of the high-level water tank 10 is normally 0.74m-0.94m. When it reaches 0.94m, a high liquid level alarm may be triggered. When it reaches 0.74m or 0.54m, a low liquid level alarm or a low-low liquid level alarm may be triggered.

[0040] In some embodiments, the circumferential side of the high-level water tank 10 can be connected to a conventional island demineralized water distribution system (SER) through a pipeline 11, and a control valve 111 is provided on the pipeline 11. The lower end of the high-level water tank 10 is connected to the first end of the connecting pipeline 20.

[0041] In some embodiments, a float valve 12 is provided in the high-level water tank 10, and water replenishment is automatically controlled by the float valve 12. The maximum water replenishment flow rate is 3.6m3 / h.

[0042] In some embodiments, a first check valve 34 is provided on a section of the first branch line 30 between the first water pump 31 and the second isolation valve 33. A second check valve 44 is provided on a section of the second branch line 40 between the second water pump 41 and the fourth isolation valve 43. A third check valve 54 is provided on a section of the third branch line 50 between the third water pump 51 and the sixth isolation valve 53.

[0043] The three water pumps in this embodiment can be two in use and one in standby during operation. For example, when the first water pump 31 and the second water pump 41 are in operation, the third water pump 51 is in standby, thereby ensuring continuous operation and reliability of the system.

[0044] In some embodiments, the first water pump 31 , the second water pump 41 , and the third water pump 51 are all horizontal centrifugal pumps, which may be 50% capacity horizontal centrifugal pumps.

[0045] In some embodiments, the first heat exchanger 71 and the second heat exchanger 81 are both tubular heat exchangers, which can be 100% capacity tubular heat exchangers. Preferably, the normal temperature value is 44°C at the inlet and 38°C at the outlet, the maximum design heat load of each heat exchanger is 27167.4kW, and the seawater flow rate is 5760m 3 / h, heat exchange area 1720m 2 .

[0046] In some embodiments, the inlet end of the second heat exchange pipe is connected to the first water inlet pipeline 711, and the outlet end of the second heat exchange pipe is connected to the first water outlet pipeline 712. The first water inlet pipeline 711 is provided with a first valve 713, and the first water outlet pipeline 712 is provided with a second valve 714. The first water inlet pipeline 711 is used to connect to a first cooling water source, such as seawater.

[0047] In some embodiments, the inlet end of the fourth heat exchange pipe is connected to the second water inlet pipeline 811, the outlet end of the fourth heat exchange pipe is connected to the second water outlet pipeline 812, the second water inlet pipeline 811 is provided with a third valve 813, and the second water outlet pipeline 812 is provided with a fourth valve 814. The second water inlet pipeline 811 is used to connect to a second cooling water source, such as seawater.

[0048] In some embodiments, the conventional island closed-circuit cooling water system of the nuclear power plant further includes a bypass pipeline 100, the two ends of the bypass pipeline 100 are respectively connected in parallel to the two ends of the second mother pipeline 90, and a bypass valve 101 is provided on the bypass pipeline 100. The function of the bypass valve 101 is to ensure that the first water pump 31, the second water pump 41, and the third water pump 51 operate at the optimal point of the characteristic curve. The bypass valve 101 controls the flow rate flowing through the pump. The bypass valve 101 can be designed to have a flow rate of 2000m 3 / h, the designed pressure drop can be 1.8bar.g.

[0049] In some embodiments, a temperature sensor is provided on the first mother line 60 and / or the second mother line 90 to monitor the temperature of the cooling water.

[0050] It can be understood that the closed-loop cooling water system of the conventional island of a nuclear power plant can be used to conduct heat and cool the coolers (or heat exchangers) of each user in the conventional island of the nuclear power plant, thereby ensuring the safe and stable operation of the coolers of each user in the conventional island of the nuclear power plant.

[0051] In addition, the conventional island closed-circuit cooling water system of the nuclear power plant can select "single cooling mode", "dual cooling mode" or "mixed cooling mode" according to needs, which improves the practicality of the conventional island closed-circuit cooling water system of the nuclear power plant.

[0052] It can be understood that the above embodiments only express the preferred implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the utility model. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the utility model, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the utility model. Therefore, all equivalent changes and modifications made to the scope of the claims of the utility model should fall within the scope of the claims of the utility model.

Claims

1. A conventional island closed-circuit cooling water system for a nuclear power plant, characterized in that: It comprises a high-level water tank (10), a connecting pipeline (20), a first branch pipeline (30), a second branch pipeline (40), a third branch pipeline (50), a first main pipeline (60), a fourth branch pipeline (70), a fifth branch pipeline (80), and a second main pipeline (90); One end of the high-level water tank (10) is used to connect to a conventional island desalted water distribution system, and the other end of the high-level water tank (10) is connected to a first end of the connecting pipeline (20); The first branch pipeline (30), the second branch pipeline (40) and the third branch pipeline (50) are arranged in parallel, and the first ends of the parallel-connected pipelines are connected to the second end of the connecting pipeline (20), and the second ends of the parallel-connected pipelines (30), the second branch pipeline (40) and the third branch pipeline (50) are connected to the first end of the first main pipeline (60); The first branch pipeline (30) is provided with a first water pump (31), and a first isolation valve (32) and a second isolation valve (33) are respectively provided upstream and downstream of the first water pump (31); the second branch pipeline (40) is provided with a second water pump (41), and a third isolation valve (42) and a fourth isolation valve (43) are respectively provided upstream and downstream of the second water pump (41); the third branch pipeline (50) is provided with a third water pump (51), and a fifth isolation valve (52) and a sixth isolation valve (53) are respectively provided upstream and downstream of the third water pump (51); The fourth branch pipeline (70) and the fifth branch pipeline (80) are arranged in parallel, and the first end after the parallel connection is connected to the second end of the first main pipeline (60), and the second end after the parallel connection of the fourth branch pipeline (70) and the fifth branch pipeline (80) is connected to the first end of the second main pipeline (90); a first heat exchanger (71) is provided on the fourth branch pipeline (70), and the first heat exchanger (71) has a first heat exchange pipeline and a second heat exchange pipeline, the first heat exchange pipeline is connected to the first branch pipeline (30), the second heat exchange pipeline is connected to the first cooling water source, and the The fourth branch pipeline (70) is located upstream and downstream of the first heat exchanger (71), and is respectively provided with a seventh isolation valve (72) and an eighth isolation valve (73); the fifth branch pipeline (80) is provided with a second heat exchanger (81), the second heat exchanger (81) has a third heat exchange pipeline and a fourth heat exchange pipeline, the first heat exchange pipeline is connected to the fifth branch pipeline (80), the fourth heat exchange pipeline is connected to a second cooling water source, and the fifth branch pipeline (80) is located upstream and downstream of the second heat exchanger (81), and is respectively provided with a ninth isolation valve (82) and a tenth isolation valve (83); The second end of the second mother pipeline (90) is connected to the connecting pipeline (20), and the second mother pipeline (90) is provided with a conventional island cooler.

2. The conventional island closed-circuit cooling water system of a nuclear power plant according to claim 1, characterized in that: A float valve (12) is provided in the high-level water tank (10).

3. The conventional island closed-circuit cooling water system of a nuclear power plant according to claim 1, characterized in that: A first check valve (34) is provided on a section of the first branch pipeline (30) between the first water pump (31) and the second isolation valve (33); A second check valve (44) is provided on a section of the second branch pipeline (40) between the second water pump (41) and the fourth isolation valve (43); A third check valve (54) is provided on a section of the third branch pipeline (50) between the third water pump (51) and the sixth isolation valve (53).

4. The conventional island closed-circuit cooling water system of a nuclear power plant according to claim 1, characterized in that: The first water pump (31), the second water pump (41) and the third water pump (51) are all horizontal centrifugal pumps.

5. The conventional island closed-circuit cooling water system of a nuclear power plant according to claim 1, characterized in that: The first heat exchanger (71) and the second heat exchanger (81) are both tubular heat exchangers.

6. The conventional island closed-circuit cooling water system of a nuclear power plant according to claim 1, characterized in that: The inlet end of the second heat exchange pipe is connected to the first water inlet pipeline (711), and the outlet end of the second heat exchange pipe is connected to the first water outlet pipeline (712). The first water inlet pipeline (711) is provided with a first valve (713), and the first water outlet pipeline (712) is provided with a second valve (714).

7. The conventional island closed-circuit cooling water system of a nuclear power plant according to claim 1, characterized in that: The inlet end of the fourth heat exchange pipe is connected to the second water inlet pipeline (811), and the outlet end of the fourth heat exchange pipe is connected to the second water outlet pipeline (812). The second water inlet pipeline (811) is provided with a third valve (813), and the second water outlet pipeline (812) is provided with a fourth valve (814).

8. The conventional island closed-circuit cooling water system of a nuclear power plant according to claim 1, characterized in that: The conventional island closed-circuit cooling water system of the nuclear power plant further comprises a bypass pipeline (100), and two ends of the bypass pipeline (100) are respectively connected in parallel to two ends of the second mother pipeline (90); The bypass pipeline (100) is provided with a bypass valve (101).

9. The conventional island closed-circuit cooling water system of a nuclear power plant according to any one of claims 1 to 8, characterized in that: The first mother pipeline (60) and / or the second mother pipeline (90) are provided with a temperature sensor.

10. The conventional island closed-circuit cooling water system of a nuclear power plant according to any one of claims 1 to 8, characterized in that: The high-level water tank (10) is provided with a liquid level gauge.

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