Water system for nuclear power station and building method

Abstract

The invention discloses a water system for a nuclear power station and a building method. The water system for the nuclear power station comprises a first pipeline, a second pipeline, a third pipeline and a reservoir. The first pipeline is used for communicating the nuclear power station with a natural water area, and the altitude of the natural water area is H1; the reservoir is built on a mountain, the altitude of the reservoir is H2, and H2-H1 is larger than or equal to 100 m; one end of the second pipeline is communicated with the reservoir, and the other end is communicated with a natural water area; one end of the third pipeline is communicated with the reservoir, and the other end is communicated with the nuclear power station; the water pumping device is arranged on the second pipeline and used for pumping water in the natural water area to the reservoir. The water body is cooled by utilizing the high-altitude reservoir, and an indoor reservoir does not need to be built, so that the building cost of the reservoir is reduced. Therefore, the reservoir can be constructed to be large enough to meet the water consumption of all workshops of the nuclear power station, so that the influence of high temperature on power generation of the nuclear power station is reduced, and the power generation efficiency of the nuclear power station is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power plants, and particularly relates to a water system for a nuclear power plant and a construction method thereof. Background Art

[0002] With the global climate warming, more and more nuclear power plants are affected by water temperature in summer, resulting in the temperature of the water taken by the nuclear power plant exceeding the normal operating temperature range, causing the nuclear power unit to reduce power, and even shut down and stop the reactor. To solve this problem, in related technologies, an indoor reservoir connected to the ocean is established, and seawater can be discharged into the indoor reservoir for cooling. When the seawater is affected by heat waves and the temperature is too high, the nuclear power plant can directly use the seawater in the indoor reservoir. However, due to cost and land occupation problems, the capacity of the indoor reservoir is limited, and the water in the indoor reservoir can only ensure the water consumption of important plant water, and cannot supply the water consumption for the normal operation of all buildings in the nuclear power plant. Therefore, the unit still needs to reduce power or shut down and stop the reactor, which affects the power generation efficiency. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, the present invention provides a water system for a nuclear power plant, which can reduce the impact of high temperature on the power generation efficiency of the nuclear power plant.

[0004] The present invention also provides a construction method for building the above-mentioned water system for a nuclear power plant.

[0005] The water system for a nuclear power plant according to the first aspect embodiment of the present invention includes: a first pipeline, a second pipeline, a third pipeline, and a reservoir.

[0006] The first pipeline is used to connect the nuclear power plant to the natural water area to allow the water body in the natural water area to flow to the nuclear power plant, and the altitude of the natural water area is H1; the reservoir is built on the mountain, and the altitude of the reservoir is H2, and H2 - H1 ≥ 100m; one end of the second pipeline is connected to the reservoir, and the other end is connected to the natural water area; one end of the third pipeline is connected to the reservoir, and the other end is connected to the nuclear power plant; a pumping device is arranged on the second pipeline to pump the water body in the natural water area to the reservoir.

[0007] The water system for a nuclear power plant according to the embodiment of the present invention has at least the following beneficial effects:

[0008] In this embodiment, the reservoir is arranged on the mountain, and the altitude of the reservoir is at least 100 m higher than that of the natural water area. It is known that the temperature can be reduced by approximately 0.6 °C for every 100 m increase in altitude. Therefore, in this embodiment, the reservoir at a high altitude is used to cool the water body, and there is no need to build an indoor reservoir, that is, there is no need to seal the reservoir, thereby reducing the construction cost of the reservoir. At the same time, the reservoir is arranged on the mountain, without occupying the construction space of the nuclear power plant, thereby saving the land cost of the nuclear power plant. Therefore, the reservoir in this embodiment can be built large enough to meet the water consumption of all the workshops in the nuclear power plant, thereby reducing the impact of high temperature on the power generation of the nuclear power plant and improving the power generation efficiency of the nuclear power plant.

[0009] According to some embodiments of the present invention, the nuclear power plant water use system further includes a forebay, the forebay includes a water storage cavity and a first water inlet and a first water outlet communicating with the water storage cavity. The first pipeline includes a first pipe body and a second pipe body. One end of the first pipe body is connected to the first water inlet, and the other end communicates with the natural water area. One end of the second pipe body is connected to the first water outlet, and the other end communicates with the natural water area.

[0010] According to some embodiments of the present invention, the forebay has a second water inlet, and the third pipeline is connected to the first water inlet.

[0011] According to some embodiments of the present invention, the first water inlet is configured to be higher than the liquid level height in the water storage cavity; and / or,

[0012] The second water inlet is configured to be higher than the liquid level height of the water storage cavity.

[0013] According to some embodiments of the present invention, the third pipeline is connected to the first pipe body.

[0014] According to some embodiments of the present invention, the forebay further includes a flow stabilizing member. The flow stabilizing member is a grid structure. The flow stabilizing member is arranged in the water storage cavity to divide the water storage cavity into an outlet cavity and an inlet cavity. The first water inlet and the second water inlet are both located on the side wall of the inlet cavity, and the first water outlet is located on the side wall of the outlet cavity.

[0015] According to some embodiments of the present invention, the nuclear power plant water use system further includes a first valve and a second valve. The first valve is arranged on the first pipeline and is used to adjust the flow cross-sectional area of the first pipeline. The second valve is arranged on the third pipeline and is used to adjust the flow cross-sectional area of the third pipeline.

[0016] According to some embodiments of the present invention, the nuclear power plant water system further includes a blocking net and a pressure sensor. The blocking net is disposed in the first pipeline and is used to intercept sundries or organisms in the natural water area from entering the first pipeline. The pressure sensor is disposed on the blocking net and is used to detect the pressure received by the blocking net. The nuclear power plant water system is configured such that when the detected value of the pressure sensor reaches a set value, the first pipeline is closed through the first valve, and the third pipeline is made in a conducting state through the second valve.

[0017] According to some embodiments of the present invention, the nuclear power plant water system further includes a fourth pipeline and a fifth pipeline. The fourth pipeline is used to connect the nuclear power plant and the natural water area to supply the water body in the nuclear power plant to flow to the natural water area;

[0018] One end of the fifth pipeline is connected to the reservoir, and the other end is connected to the fourth pipeline.

[0019] According to some embodiments of the present invention, the nuclear power plant water system further includes a siphon well. The fourth pipeline includes a third pipe body and a fourth pipe body. One end of the third pipe body is connected to the siphon well, and the other end is used to communicate with the nuclear power plant. One end of the fourth pipe body is connected to the siphon well, and the other end is used to communicate with the natural water area.

[0020] According to some embodiments of the present invention, the nuclear power plant water system further includes a third valve. The third valve is disposed on the fifth pipeline and is used to adjust the flow cross-sectional area of the fifth pipeline.

[0021] According to some embodiments of the present invention, the pumping device is set as a pumped-storage power generation motor.

[0022] According to some embodiments of the present invention, the second pipeline has a second water outlet. The third pipeline is connected to the second water outlet. The pumped-storage power generation motor is disposed between the second water outlet and the reservoir. The nuclear power plant water system further includes a fourth valve. The fourth valve is disposed on the second pipeline and is located between the second water outlet and the natural water area.

[0023] According to an embodiment of the second aspect of the present invention, a method for building a nuclear power plant water system is used to build the nuclear power plant water system described in the above embodiments. The building method includes the following steps:

[0024] Site selection. The selected building site is an area near a pumped-storage power station that has already been built. The pumped-storage power station includes the reservoir, the second pipeline, and the pumped-storage power generation motor. The second pipeline communicates with the reservoir and the natural water area. The pumped-storage power generation motor is disposed on the second pipeline;

[0025] Laying pipes, laying the first pipe and connecting the first pipe to the nuclear power plant and the natural water area; and,

[0026] Laying the third pipe and providing the second water outlet on the second pipe, the second water outlet being located between the pumped-storage power generation motor and the natural water area, and connecting the third pipe to the second water outlet.

[0027] The method for building a water system for a nuclear power plant according to an embodiment of the present invention has at least the following beneficial effects:

[0028] In this embodiment, the existing pumped-storage power station is utilized for water storage without the need for additional construction, thereby reducing the construction cost of the water system for the nuclear power plant.

[0029] The additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the drawings and embodiments, wherein:

[0031] Figure 1 is a schematic diagram of a water system for a nuclear power plant according to the first embodiment of the present invention;

[0032] Figure 2 is a schematic diagram of a water system for a nuclear power plant according to the second embodiment of the present invention;

[0033] Figure 3 is Figure 3 a schematic diagram of the forebay and the first pipe in

[0034] Figure 4 is Figure 3 another schematic diagram of the forebay and the first pipe in

[0035] Figure 5 is Figure 3 a schematic diagram of the forebay, the first pipe and the third pipe in

[0036] Figure 6 is Figure 3 another schematic diagram of the forebay and the first pipe in

[0037] Figure 7 is a schematic diagram of a water system for a nuclear power plant according to the third embodiment of the present invention.

[0038] Reference Signs:

[0039] Nuclear power plant 1000, natural water area 2000;

[0040] First valve 10, second valve 20, third valve 30, fourth valve 40;

[0041] The first pipeline 100, the first pipe body 110, the second pipe body 120;

[0042] The second pipeline 200, the second water outlet 210;

[0043] The reservoir 300, the third pipeline 400, the fourth pipeline 500, the fifth pipeline 600;

[0044] The forebay 700, the water storage cavity 710, the water inlet cavity 711, the water outlet cavity 712, the first water inlet 720, the first water outlet 730, the second water inlet 740, the flow stabilizing member 750;

[0045] The siphon well 800;

[0046] The pumping device 900, the pumped-storage power generation motor 901. Specific embodiments

[0047] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0048] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0049] In the description of the present invention, the meaning of several is more than one, the meaning of multiple is more than two, and understandings such as greater than, less than, exceeding, etc. do not include the present number, and understandings such as above, below, within, etc. include the present number. If the first and second are described only for the purpose of distinguishing technical features, they should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence of the indicated technical features.

[0050] In the description of the present invention, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0051] In the description of the present invention, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0052] With the global warming, more and more nuclear power plants are affected by heat waves in summer, resulting in the temperature of the water taken by the nuclear power plant exceeding the normal operating temperature range, causing the power reduction of the nuclear power unit, and even shutdown of the reactor. To solve this problem, in the related art, an indoor reservoir connected to the ocean is established, and seawater can be discharged into the indoor reservoir for cooling. When the seawater is affected by the heat wave and the temperature is too high, the nuclear power plant can directly use the seawater in the indoor reservoir. However, due to the cost (large area of capping, high cost) and land occupation problems, the capacity of the indoor reservoir is limited. The water in the indoor reservoir can only ensure the water consumption of the important plant water supply, and cannot supply the water consumption for the normal operation of all workshops in the nuclear power plant. Therefore, the unit still needs to reduce power or shut down, which affects the power generation efficiency.

[0053] In view of the above problems, the first aspect embodiment of the present invention provides a water system for a nuclear power plant. The water system for a nuclear power plant includes, but is not limited to, nuclear safety water and power generation water. Among them, the nuclear safety water is: the important plant water supply system (SEC) transports the heat load collected by the RRI system to the heat sink - the sea through the RRI / SEC heat exchanger of the reactor coolant system (RRI). The water volume is about 1 m 3 / s. Since the RRI system provides cooling water for important safety equipment in the nuclear power plant, the important plant water supply system is a nuclear safety related system. Power generation water: The function of the circulating water system (CRF) is to provide cooling water for the condenser of the steam turbine generator. The cooling water comes from seawater. After taking away the heat of the heat exchange equipment, it is discharged to the siphon well and then discharged to the open sea through the siphon well.

[0054] Refer to Figure 1 , Figure 1 FIG. is a schematic diagram of the water system for a nuclear power plant according to the first embodiment of the present invention. The water system for a nuclear power plant of this embodiment includes: a first pipeline 100, a second pipeline 200, a third pipeline 400, and a reservoir 300.

[0055] Among them, the first pipeline 100 is used to connect the nuclear power plant 1000 and the natural water area 2000. The first pipeline 100 is used to supply the water body of the natural water area 2000 to flow towards the nuclear power plant 1000. It can flow towards the nuclear power plant 1000 by using gravitational potential energy, or be pumped to the nuclear power plant 1000 by using pumping equipment. The natural water area 2000 is, for example, a lake, a river, a stream or an ocean, etc. The altitude of the natural water area 2000 is H1. The reservoir 300 is built on the mountain body, and the altitude of the reservoir 300 is H2, and H2 - H1 ≥ 100m. One end of the second pipeline 200 is connected to the reservoir 300, and the other end is connected to the natural water area 2000. One end of the third pipeline 400 is connected to the reservoir 300, and the other end is connected to the nuclear power plant 1000. The pumping device 900 is arranged in the second pipeline 200 and is used to pump the water body of the natural water area 2000 to the reservoir 300. Specifically, according to the vertical lapse rate of temperature, for every 100 meters increase in altitude, the temperature drops by about 0.6°C on average. For example, in this embodiment, H2 - H1 = 100m, then the temperature of the reservoir 300 is 0.6°C lower than the temperature of the natural water area 2000. Or in some embodiments, H2 - H1 = 900m, then the temperature of the reservoir 300 is 5.4°C lower than the temperature of the natural water area 2000. Therefore, after pumping the water body of the natural water area 2000 to the reservoir 300, the water body can be cooled. When the water body of the natural water area 2000 is higher than the operating temperature of the nuclear power plant 1000 due to the influence of high temperature, the nuclear power plant 1000 can directly use the water body of the reservoir 300 or use the low-temperature water in the reservoir 300 to mix and cool the water body of the natural water area 2000 and then use it for the nuclear power plant 1000 to ensure that the water temperature used by the nuclear power plant does not exceed the safe operating temperature of the nuclear power plant, guarantee nuclear safety and the normal operation of the unit, thereby reducing the power generation loss caused by shutdown or derating.

[0056] It can be understood that in this embodiment, the reservoir 300 at a high altitude is used to cool the water body, and there is no need to build an indoor reservoir 300, that is, there is no need to seal the reservoir 300, thereby reducing the construction cost of the reservoir 300. At the same time, the reservoir 300 is arranged on the mountain body and does not need to occupy the construction space of the nuclear power plant 1000, thereby saving the land cost of the nuclear power plant 1000. Therefore, the reservoir 300 of this embodiment can be built large enough at a relatively lower cost to meet the water consumption of all workshops of the nuclear power plant 1000, and further reduce the impact of high temperature on the power generation of the nuclear power plant 1000 to improve the power generation efficiency of the nuclear power plant 1000.

[0057] Refer to Figure 2 and Figure 3 , Figure 2 is a schematic diagram of the nuclear power plant water system according to the second embodiment of the present invention, Figure 3 is Figure 2Schematic diagram of the forebay and the first pipeline. In some embodiments, the water system of the nuclear power plant further includes a forebay 700. The forebay 700 includes a water storage chamber 710, a first water inlet 720, and a first water outlet 730 that communicate with the water storage chamber 710. The first pipeline 100 includes a first pipe body 110 and a second pipe body 120. One end of the first pipe body 110 is connected to the first water inlet 720, and the other end is connected to the natural water area 2000. One end of the second pipe body 120 is connected to the first water outlet 730, and the other end communicates with the natural water area 2000. Specifically, the forebay 700 is located between the natural water area 2000 and the nuclear power plant 1000 and can serve as a buffer zone to reduce the water flow velocity, allowing suspended sediment and debris to settle naturally and reducing damage to the nuclear power plant 1000. In addition, after the water from the natural water area 2000 enters the forebay 700, the turbulence of the water body can be reduced through static settlement, making the water body more stable. As a result, the water flow rate entering the nuclear power plant 1000 becomes more stable, improving the accuracy of the water consumption of the nuclear power plant 1000 and thus enhancing the power generation efficiency of the nuclear power plant 1000.

[0058] Refer to Figure 4 , Figure 4 is Figure 2 Another schematic diagram of the forebay and the first pipeline in []. In some embodiments, the forebay 700 has a second water inlet 740, and the third pipeline 400 is connected to the first water inlet 720. It can be seen that when the water body of the reservoir 300 flows towards the nuclear power plant 1000, it first flows into the forebay 700. When the nuclear power plant 1000 directly uses the water body of the reservoir 300, the effect of the forebay 700 is the same as when the nuclear power plant 1000 uses the water body of the natural water area 2000, which will not be elaborated here.

[0059] Refer to Figure 3 , in some embodiments, the first water inlet 720 is configured to be higher than the liquid level in the water storage chamber 710, so that the water body entering the water storage chamber 710 via the first water inlet 720 forms a disturbance to the water in the water storage chamber 710, thereby improving the mixing degree of the high-temperature water body (higher than the safety temperature of the nuclear power plant 1000) of the natural water area 2000 entering via the first water inlet 720 and the low-temperature water body (lower than the safety temperature of the nuclear power plant 1000) of the reservoir 300 entering via the second water inlet 740. Furthermore, the temperature accuracy of the water body entering the nuclear power plant 1000 is improved to enhance the power generation efficiency of the nuclear power plant 1000.

[0060] Similarly, in some embodiments, the second water inlet 740 is configured to be higher than the liquid level in the water storage chamber 710, which will not be elaborated here.

[0061] Furthermore, refer to Figure 4, in some embodiments, the first water inlet 720 is configured to be lower than the liquid level in the water storage chamber 710, and the second water inlet 740 is configured to be higher than the liquid level in the water storage chamber 710. Specifically, during the operation of the nuclear power plant 1000, the water temperature of the natural water area 2000 is relatively rarely higher than the water use requirement of the nuclear power plant 1000 due to high temperature (usually only occurs during high-temperature periods in summer). When the water temperature of the natural water area 2000 is lower than the water use requirement of the nuclear power plant 1000, it can be directly used by the nuclear power plant 1000 without the need for mixing and cooling with the low-temperature water body in the reservoir 300. In this embodiment, the first water inlet 720 is arranged lower than the liquid level in the water storage chamber 710. Therefore, when the nuclear power plant 1000 directly uses the water body of the natural water area 2000, the water flow needs to overcome the hydrostatic pressure of the water body around the first water inlet 720 when entering the forebay. Its initial kinetic energy is absorbed and dispersed by the surrounding water body, and the flow velocity is significantly reduced. Compared with the free-fall water inlet above the liquid level, the underwater water inlet can avoid the water flow directly impacting the water surface to form splashes and vortices, reducing the generation of turbulent energy. On the one hand, it can reduce the agitation of the bottom sediment, and on the other hand, it can improve the accuracy of the water flow rate entering the nuclear power plant 1000, thereby improving the power generation efficiency of the nuclear power plant 1000. On this basis, in order to ensure the mixing degree of the low-temperature water body and the high-temperature water body when the low-temperature water body in the reservoir 300 needs to be utilized, the second water inlet 740 in this embodiment is arranged higher than the liquid level of the water storage chamber 710. Therefore, when the water bodies of the natural water area 2000 and the water body in the reservoir 300 are utilized simultaneously, the free fall through the second water inlet 740 can be used to disturb the surrounding water body, thereby improving the uniformity of the water temperature in the water storage chamber 710 to improve the power generation efficiency of the nuclear power plant 1000. In addition, it can be understood that the density of the low-temperature water body is greater than that of the high-temperature water body. Therefore, after the high-temperature water body in the natural water area 2000 enters the water storage chamber 710, it will move upward, and the low-temperature water body in the reservoir 300 will move downward after entering the water storage chamber 710, thereby further improving the mixing degree of the low-temperature water body and the high-temperature water body, and thus improving the uniformity of the water temperature in the water storage chamber 710.

[0062] In some embodiments, the third pipe 400 is connected to the first pipe body 110. Thus, the low-temperature water body in the reservoir 300 is first mixed with the high-temperature water body of the natural water area 2000 in the first pipe 100 before entering the forebay 700, and then enters the forebay 700 through the first water inlet 720, further improving the mixing degree of the low-temperature water body and the high-temperature water body.

[0063] As can be seen from the above embodiments, in order to improve the uniformity of the water temperature in the forebay 700, the water body in the forebay 700 is disturbed by using the low-temperature water body or the high-temperature water body. However, this will also affect the water flow rate entering the nuclear power plant 1000 through the first water outlet 730 and affect the accuracy of the water consumption of the nuclear power plant 1000. Based on this, in order to improve the accuracy of the water consumption of the nuclear power plant 1000, refer toFigure 5 , Figure 5 is Figure 3 a schematic diagram of the forebay, the first pipeline and the third pipeline in

[0064] In some embodiments, the forebay 700 has a first position and a second position with the maximum distance in the horizontal direction. The first water inlet 720 and the second water inlet are located at the first position, and the first water outlet 730 is located at the second position. Exemplarily, the forebay 700 is a circular water pool, and the first position and the second position are located on two radially opposite side walls of the forebay 700. Alternatively, the forebay 700 is a rectangular water pool, and the first position and the second position are located on the diagonal of the forebay 700. Specifically, taking the first water inlet 720 as an example, after the water body enters the water storage cavity 710 through the first water inlet 720, it will cause a certain disturbance to the water body in the water storage cavity 710. Therefore, in this embodiment, the first water outlet 730 is set at the position farthest from the first water inlet 720 to reduce the disturbance of the water body entering the water storage cavity 710 through the first water inlet 720 to the water body around the first water outlet 730, thereby improving the water flow accuracy of the water entering the nuclear power plant 1000 through the first water outlet 730 and improving the power generation efficiency of the nuclear power plant 1000.

[0065] Referring to Figure 6 , Figure 6 is Figure 2Another schematic diagram of the forebay and the first pipeline. In some embodiments, the forebay 700 has an L-shaped or V-shaped structure, and its first water inlet 720 and the first water outlet 730 are respectively arranged at both ends of the forebay 700. Specifically, taking the forebay 700 with an L-shaped structure as an example, the forebay 700 is composed of a water inlet chamber 711 and a water outlet chamber 712, and the two are interconnected to form an L-shaped cavity. The first water inlet 720 is located on the side of the water inlet chamber 711 far from the water outlet chamber 712, while the first water outlet 730 is located on the side of the water outlet chamber 712 far from the water inlet chamber 711. Therefore, after the water body enters the water storage chamber 710 through the first water inlet 720, it needs to pass through a corner during the flow to the first water outlet 730, which helps to reduce the flow velocity of the water body. Correspondingly, this reduces the disturbance of the water body entering the water storage chamber 710 from the first water inlet 720 to the water body at the first water outlet 730, thereby improving the accuracy of the water flow rate entering the nuclear power plant 1000 through the first water outlet 730, enhancing the power generation efficiency of the nuclear power plant 1000, and making its operation more efficient and reliable. Further, the design of the L-shaped forebay 700 not only optimizes the water flow velocity but also takes into account the uniform distribution of the water flow inside the forebay 700. Since the water flow is forced to change direction at the corner, this process promotes the mixing and redistribution of the water flow in the entire cavity, reducing the situation of too strong or too weak local water flow, which is crucial for maintaining the stability of the cooling system of the nuclear power plant 1000. In addition, compared with the linear design, the L-shaped structure can provide a longer water flow path in a limited space, enabling the full mixing of low-temperature water bodies and high-temperature water bodies.

[0066] Refer to Figure 7 , Figure 7Schematic diagram of the water system for a nuclear power plant according to the third embodiment of the present invention. In some embodiments, the water system for the nuclear power plant further includes a first valve 10 and a second valve 20. The first valve 10 is disposed on the first pipeline 100 and is used to adjust the flow cross-sectional area of the first pipeline 100 (the flow cross-sectional area refers to the geometric area of the minimum effective flow cross-section perpendicular to the flow direction when the fluid flows through the pipeline or valve). The second valve 20 is disposed on the third pipeline 400 and is used to adjust the flow cross-sectional area of the third pipeline 400. Specifically, during the operation of the nuclear power plant 1000, the flow cross-sectional area of the first pipeline 100 can be adjusted through the first valve 10 to adjust the flow rate of the high-temperature water body entering the forebay 700, and the flow cross-sectional area of the third pipeline 400 can be adjusted through the second valve 20 to adjust the flow rate of the low-temperature water entering the forebay 700, thereby adjusting the water temperature in the forebay 700 to meet the usage requirements of the nuclear power plant 1000. In addition, for the water bodies in natural water areas 2000 with different temperatures, through the coordinated action of the first valve 10 and the second valve 20, the water temperature in the forebay 700 can meet the water usage requirements of the nuclear power plant 1000. For example, when the water temperature in the natural water area 2000 is too high, the flow cross-sectional area of the first pipeline 100 can be reduced through the first valve 10, and the flow cross-sectional area of the third pipeline 400 can be increased through the second valve 20, so that the water system for the nuclear power plant in this embodiment can cool the water temperature in natural water areas 2000 with different temperatures, improving the practicability of the water system for the nuclear power plant in this embodiment.

[0067] In some embodiments, the water system of a nuclear power plant further includes a barrier net and a pressure sensor. The barrier net is arranged in the first pipeline 100 and is used to intercept sundries or organisms in the natural water area 2000 from entering the first pipeline 100. The pressure sensor is arranged on the barrier net and is used to detect the pressure received by the barrier net. The water system of the nuclear power plant is configured such that when the detected value of the pressure sensor reaches a set value, the first pipeline 100 is closed through the first valve 10 and the third pipeline 400 is made to conduct. Specifically, it can be understood that there are certain aquatic organisms and sundries in the natural water area 2000. In order to prevent aquatic organisms or sundries from entering the nuclear power plant 1000, a barrier net is arranged in the first pipeline 100 in this embodiment. The barrier net is, for example, arranged at the water inlet of the first pipeline 100. However, when there are more sundries or aquatic organisms, they will accumulate at the barrier net, resulting in the blockage of the first pipeline 100 and affecting the water use of the nuclear power plant 1000. Moreover, when the sundries or aquatic organisms are blocked at the barrier net, the pressure on the barrier net will increase. Based on this, a pressure sensor is also arranged on the barrier net in this embodiment. When the detected value of the pressure sensor reaches the set value (the set value is set according to the pipe diameter of the first pipeline 100, etc.), it indicates that the first pipeline 100 is blocked. At this time, the first pipeline 100 is closed through the first valve 10, and the flow cross-sectional area of the third pipeline 400 is increased, so that the water storage tank 300 supplies water to the nuclear power plant 1000 to meet the water consumption of the nuclear power plant 1000, thereby ensuring the power generation efficiency and safety of the nuclear power plant 1000. Exemplarily, the water system of the nuclear power plant further includes a controller. The first valve 10 and the second valve 20 are both electric valves. The first valve 10, the second valve 20, and the pressure sensor are all communicatively connected to the controller. When the detected value of the pressure sensor reaches the set value, the detection signal of the pressure sensor changes and the signal is transmitted to the controller. The controller sends signals to the first valve 10 and the second valve 20 to close the first pipeline 100 and increase the flow cross-sectional area of the third pipeline 400, without the need for manual operation, thus avoiding affecting the power generation efficiency and safety of the nuclear power plant 1000 due to the time difference of manual operation (the time required for manual reception of the signal and then operation of the valve).

[0068] In some embodiments, the water system of the nuclear power plant further includes a fourth pipe 500 and a fifth pipe 600. The fourth pipe 500 is used to connect the nuclear power plant 1000 and the natural water area 2000 to allow the water body in the nuclear power plant 1000 to flow to the natural water area 2000. One end of the fifth pipe 600 is connected to the reservoir 300, and the other end is connected to the fourth pipe 500 to cool the water discharged from the nuclear power plant 1000 to ensure that the drainage temperature does not exceed the regulatory standard requirements. On this basis, in some embodiments, the water system of the nuclear power plant further includes a siphon well 800. The fourth pipe 500 includes a third pipe body and a fourth pipe body. One end of the third pipe body is connected to the siphon well 800, and the other end is used to communicate with the nuclear power plant 1000. One end of the fourth pipe body is connected to the siphon well 800, and the other end is used to communicate with the natural water area 2000. The siphon well 800 is used to prevent seawater backflow or siphon interruption, and the stilling basin slows down the water flow impact through the hydraulic jump phenomenon. Specifically, the siphon well 800 includes, for example, an overflow weir, a breather, and an energy dissipation facility. The overflow weir maintains the full-flow state of the pipeline to reduce the energy consumption of the water pump. The breather automatically adjusts the air pressure through a float valve to prevent seawater backflow or siphon interruption, and the stilling basin slows down the water flow impact through the hydraulic jump phenomenon.

[0069] In some embodiments, the water system of the nuclear power plant further includes a third valve 30. The third valve 30 is disposed on the fifth pipe 600 to adjust the flow cross-sectional area of the fifth pipe 600 to adjust the drainage temperature of the nuclear power plant 1000. For example, when the temperature of the water discharged from the nuclear power plant 1000 to the siphon well 800 is too high, the third valve 30 can be used to increase the flow cross-sectional area of the fifth pipe 600, thereby reducing the drainage temperature and improving the practicability of the water system of the nuclear power plant in this embodiment.

[0070] Refer to Figure 7 , in some embodiments, the pumping device 900 is set as a pumped-storage power generation motor 901. Specifically, the pumped-storage power generation motor 901 realizes energy conversion through a motor-generator with two-way operation, and pumps the water body in the natural water area 2000 to the reservoir 300 at a high altitude for energy storage during the low grid load period. It can be known that the pumped-storage power generation motor 901 consumes electricity for energy storage during this process. During the high grid load period, the water in the reservoir 300 is released, and the pumped-storage power generation motor 901 is rotated to generate electricity by using the gravitational potential energy to relieve the grid pressure. Specifically, the water system of the nuclear power plant in this embodiment can not only meet the water demand of the nuclear power plant 1000, but also relieve the grid pressure through "peak shaving and valley filling", thereby improving the practicability of the water system of the nuclear power plant in this embodiment, and there is no need to build a separate pumped-storage power station, thus saving the construction cost.

[0071] Refer to Figure 7, in some embodiments, the second pipeline 200 has a second water outlet 210, the third pipeline 400 is connected to the second water outlet 210, the pumped-storage power generation motor 901 is arranged between the second water outlet 210 and the reservoir 300, the nuclear power plant water system further includes a fourth valve 40, and the fourth valve 40 is arranged on the second pipeline 200 and is located between the second water outlet 210 and the natural water area 2000. Therefore, when the nuclear power plant 1000 is operating, the flow direction of the water flowing out of the reservoir 300 can be controlled through the second valve 20 and the fourth valve 40. For example, when the water temperature of the natural water area 2000 meets the water use requirements of the nuclear power plant 1000, at this time, the nuclear power plant 1000 can directly use the water body of the natural water area 2000 without using the water body in the reservoir 300. Therefore, during the peak electricity consumption period, the second pipeline 200 is conducted through the fourth valve 40, and the third pipeline 400 is closed through the second valve 20. Therefore, when the reservoir 300 discharges water for power generation, the water body in the reservoir 300 is directly discharged into the natural water area 2000. When the water temperature of the natural water area 2000 is higher than the water use requirements of the nuclear power plant 1000, the second pipeline 200 is closed through the fourth valve 40, and the third pipeline 400 is conducted through the second valve 20. Therefore, when the reservoir 300 discharges water for power generation, the water body of the reservoir 300 is discharged into the forebay 700 to cool the water body of the natural water area 2000. That is, in this embodiment, the water body in the reservoir 300 cools the water body of the natural water area 2000 while being used for power generation, thereby saving water costs, that is, reducing the operating costs of the nuclear power plant 1000.

[0072] It can be known that due to factors such as the vertical attenuation of solar radiation, the lower the water temperature at deeper positions in the reservoir 300. Based on this, on the basis of the above embodiments, the opening where the second pipeline 200 is connected to the reservoir 300 is the water inlet and outlet. The water body of the natural water area 2000 enters the reservoir 300 through the water inlet and outlet, and the water body in the reservoir 300 enters the second pipeline 200 through the water inlet and outlet and enters the forebay 700. The water inlet and outlet is set to be at least 30 m lower than the liquid level in the reservoir 300, so as to further reduce the water temperature entering the forebay 700 through the reservoir 300.

[0073] The present invention also discloses a usage method of a nuclear power plant water system, and the specific steps are as follows:

[0074] From 12:00 to 16:00, close the fourth valve 40 and open the third valve 30 so that the water body in the reservoir 300 flows through the pumped-storage power generation motor 901 and flows back to the reservoir 300;

[0075] From 2:00 to 7:00, open the fourth valve 40, close the third valve 30, and start the pumped-storage power generation motor 901 to pump the water body of the natural water area 2000 to the reservoir 300.

[0076] Specifically, it can be known that as the solar altitude angle increases, the solar radiation absorbed by the ground exceeds the dissipated heat, and the temperature of the natural water area 2000 gradually increases. Especially in summer, during the period from 12:00 to 16:00, the water temperature of the natural water area 2000 exceeds the water temperature required for the nuclear power plant 1000. At this time, it is also the period when the power consumption of air conditioners and fans is the highest (the temperature is high during this period, and the cooling demand increases). Based on this, in the method for using the nuclear power plant water system in this embodiment, from 12:00 to 16:00, the fourth valve 40 is closed, and the third valve 30 is opened, so that the water in the reservoir 300 flows through the pumped-storage power generation motor 901 and flows back to the reservoir 300. That is, during this period, the low-temperature water in the reservoir 300 cools the water entering the nuclear power plant water system while generating electricity to relieve the power grid pressure. During the period from 2:00 to 7:00, the external temperature is relatively low. At this time, the water temperature of the natural water area 2000 is relatively low, and the power consumption is relatively low. At this time, the water in the natural water area 2000 is pumped to the reservoir 300 for use during high temperature. That is, during this period, not only can the water with a relatively low temperature be stored, but also the problem of the nuclear power plant 1000 being unable to consume electricity can be solved. In summary, the method for using the nuclear power plant water system in this embodiment can enable the reservoir 300 in the nuclear power plant water system to cool the water entering the nuclear power plant 1000 while discharging water for power generation, and store low-temperature water while pumping energy for storage. That is, the nuclear power plant water system of this embodiment realizes the dual functions of the reservoir 300 during the processes of discharging water for power generation and pumping energy for storage through spatio-temporal coupling and functional integration.

[0077] According to the method for constructing a nuclear power plant water system according to the second aspect embodiment of the present invention, which is used to construct the nuclear power plant water system of the above embodiment, the construction method includes the following steps:

[0078] Site selection: The selected construction site is an area near an existing pumped-storage power station. The pumped-storage power station includes a reservoir 300, a second pipeline 200, and a pumped-storage power generation motor. The second pipeline 200 is connected between the reservoir 300 and the natural water area 2000, and the pumped-storage power generation motor is arranged on the second pipeline 200.

[0079] Pipe laying: Lay the first pipeline 100 and connect the first pipeline 100 between the nuclear power plant 1000 and the natural water area 2000; and,

[0080] Lay the third pipeline 400, and set a second water outlet 210 on the second pipeline 200. The second water outlet 210 is located between the pumped-storage power generation motor and the natural water area 2000, and connect the third pipeline 400 to the second water outlet 210.

[0081] Specifically, in this embodiment, there is no need to additionally construct a large-capacity water storage tank 300 and a water intake structure, and there is no problem of land shortage at the nuclear power plant site. It only needs to lead a pipeline from the drainage pipeline of the pumped storage power station to the nuclear power unit, thereby reducing the construction cost.

[0082] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made without departing from the spirit of the present invention within the knowledge scope of those of ordinary skill in the art. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A water system for a nuclear power plant, characterized in that, Comprising: A first pipeline for connecting a nuclear power plant to a natural water area to allow the water body in the natural water area to flow towards the nuclear power plant, where the elevation of the natural water area is H1; A reservoir built on a mountain, with the elevation of the reservoir being H2, and H2 - H1 ≥ 100m; A second pipeline, one end of which is connected to the reservoir and the other end is connected to the natural water area; A third pipeline, one end of which is connected to the reservoir and the other end is connected to the nuclear power plant; A pumping device arranged in the second pipeline for pumping the water body in the natural water area to the reservoir.

2. The nuclear power plant water system according to claim 1, wherein, The nuclear power plant water system further includes a forebay, which includes a water storage chamber, a first water inlet and a first water outlet communicating with the water storage chamber. The first pipeline includes a first pipe body and a second pipe body. One end of the first pipe body is connected to the first water inlet and the other end communicates with the natural water area. One end of the second pipe body is connected to the first water outlet and the other end communicates with the natural water area.

3. The water system for nuclear power plants according to claim 2, wherein The forebay has a second water inlet, and the third pipeline is connected to the first water inlet.

4. The water system for nuclear power plants according to claim 3, characterized in that, The first water inlet is configured to be higher than the liquid level height in the water storage chamber; and / or, The second water inlet is configured to be higher than the liquid level height in the water storage chamber.

5. The nuclear power plant water system according to claim 4, characterized in that, The third pipeline is connected to the first pipe body.

6. The water system for nuclear power plants according to claim 4, characterized in that, The forebay further includes a flow stabilizing member, which is a grid structure. The flow stabilizing member is arranged in the water storage chamber to divide the water storage chamber into an outlet chamber and an inlet chamber. The first water inlet and the second water inlet are both located on the side wall of the inlet chamber, and the first water outlet is located on the side wall of the outlet chamber.

7. The water system for a nuclear power plant according to claim 1, characterized in that, The nuclear power plant water system further includes a first valve and a second valve. The first valve is arranged in the first pipeline and is used to adjust the flow cross-sectional area of the first pipeline. The second valve is arranged in the third pipeline and is used to adjust the flow cross-sectional area of the third pipeline.

8. The water system for nuclear power plants according to claim 7, characterized in that, The nuclear power plant water system further includes a blocking net and a pressure sensor. The blocking net is arranged in the first pipeline to intercept sundries or organisms in the natural water area from entering the first pipeline. The pressure sensor is arranged on the blocking net to detect the pressure received by the blocking net. The nuclear power plant water system is configured such that when the detected value of the pressure sensor reaches a set value, the first pipeline is closed through the first valve and the third pipeline is made in a conducting state through the second valve.

9. The nuclear power plant water system according to claim 1, wherein, The nuclear power plant water system further includes a fourth pipeline and a fifth pipeline. The fourth pipeline is used to connect the nuclear power plant and the natural water area to allow the water body in the nuclear power plant to flow towards the natural water area; One end of the fifth pipeline is connected to the reservoir and the other end is connected to the fourth pipeline.

10. The nuclear power plant water system according to claim 9, characterized in that, The nuclear power plant water system further includes a siphon well. The fourth pipeline includes a third pipe body and a fourth pipe body. One end of the third pipe body is connected to the siphon well and the other end is used to communicate with the nuclear power plant. One end of the fourth pipe body is connected to the siphon well and the other end is used to communicate with the natural water area.

11. The water system for a nuclear power plant according to claim 9, wherein The nuclear power plant water system further includes a third valve. The third valve is arranged in the fifth pipeline and is used to adjust the flow cross-sectional area of the fifth pipeline.

12. The water system for a nuclear power plant according to claim 1, characterized in that, The pumping device is set as a pumped storage power generation motor.

13. The water system for a nuclear power plant according to claim 12, wherein The second pipeline has a second water outlet, the third pipeline is connected to the second water outlet, the pumped-storage power generation motor is arranged between the second water outlet and the reservoir, the nuclear power plant water use system further includes a fourth valve, and the fourth valve is arranged in the second pipeline and located between the second water outlet and the natural water area.

14. Method for building a water system for a nuclear power plant, characterized in that, For building the nuclear power plant water use system described in claim 13, the building method includes the following steps: Site selection, the selected building site is an area near a pumped-storage power station that has already been built. The pumped-storage power station includes the reservoir, the second pipeline, and the pumped-storage power generation motor. The second pipeline is communicated with the reservoir and the natural water area, and the pumped-storage power generation motor is arranged on the second pipeline; Pipe laying, laying the first pipeline and making the first pipeline communicate the nuclear power plant and the natural water area; and, Laying the third pipeline and setting the second water outlet on the second pipeline. The second water outlet is located between the pumped-storage power generation motor and the natural water area, and making the third pipeline connected to the second water outlet.

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