Pool type liquid metal cooled fast reactor and method for cooling a pump support of a pool type liquid metal cooled fast reactor

Abstract

Embodiments of the present application relate to the field of internal cooling of a nuclear fast reactor pressure vessel, and in particular to a pool type liquid metal cooled fast reactor and a method of cooling a pump support of the pool type liquid metal cooled fast reactor. The fast reactor includes a main vessel, a hot / cold pool separator, a core assembly, a heat exchanger, a pump, a flow distribution assembly, a pump support, and a pump support cooling member. The hot / cold pool separator separates the main vessel containing a coolant into a hot pool and a cold pool; the coolant of the cold pool flows through the core assembly and enters the hot pool; the heat exchanger cools the coolant in the hot pool and causes the coolant to enter the cold pool; the pump pumps the coolant in the cold pool to the flow distribution assembly; the flow distribution assembly distributes the coolant to the core assembly and a pump support cooling flow path; and the pump support cooling member forms the pump support cooling flow path, and the coolant flowing out of the pump support cooling flow path returns to the hot pool and the cold pool. Embodiments of the present application provide a fast reactor capable of cooling the pump support while avoiding significantly increasing the complexity of the system.

Description

Technical Field

[0001] The embodiments of this application relate to the technical field of internal cooling of the pressure vessel of a nuclear fast reactor, specifically to a pool-type liquid metal cooled fast reactor and a method for cooling the pump support of the pool-type liquid metal cooled fast reactor. Background Technology

[0002] The statements herein are provided merely as background information in connection with this application and do not necessarily constitute prior art.

[0003] In a pool-type liquid metal-cooled fast reactor, the entire primary circuit system (including the core, main pumps, and intermediate heat exchangers) is located within the main vessel. The pump support is a crucial load-bearing structure of the pool-type liquid metal-cooled fast reactor, bearing the entire load of the reactor's main pumps. Currently, the pump support suffers from drawbacks that make long-term stable operation difficult. Summary of the Invention

[0004] A brief overview of this application is provided below to offer a basic understanding of certain aspects thereof. It should be understood that this overview is not an exhaustive summary of the application. It is not intended to identify key or essential parts of the application, nor is it intended to limit its scope. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0005] To address the aforementioned issues, embodiments of this application provide a pool-type liquid metal cooled fast reactor and a method for cooling the pump support of the pool-type liquid metal cooled fast reactor.

[0006] In a first aspect, embodiments of this application provide a pool-type liquid metal cooled fast reactor, comprising a main vessel, a hot and cold pool partition, a core assembly, a heat exchanger, a pump, a flow distribution assembly, a pump support, and a pump support cooling component. The main vessel contains coolant; the hot and cold pool partition divides the main vessel into a hot pool and a cold pool; the core assembly is disposed within the main vessel, and coolant from the cold pool flows through the core assembly into the hot pool; the heat exchanger cools the coolant in the hot pool before it enters the cold pool; the pump pumps the coolant from the cold pool to the flow distribution assembly, which distributes the coolant to the core assembly; the pump support supports the pump; the pump support cooling component is configured to form a pump support cooling channel on the radially outer side of the pump support for cooling the pump support; the flow distribution assembly further distributes coolant into the pump support cooling channel; and the pump support cooling component is further configured to allow coolant flowing out of the pump support cooling channel to return to the hot and cold pools.

[0007] The fast reactor provided in the embodiments of this application forms a pump support cooling channel by setting a pump support cooling component. The coolant in the cold pool is pumped to the flow distribution component by a pump, and the coolant is distributed to the core assembly and the pump support cooling channel by the flow distribution component. This allows for full utilization of the existing pumps and channels in the fast reactor to provide coolant to the pump support cooling channel for cooling the pump support. Without significantly increasing the complexity of the primary loop flow channel, the cooling of the fast reactor pump support by pool-type liquid metal is achieved, ensuring that the pump support temperature meets the long-term stable operation requirements during fast reactor operation, and thus ensuring that the pump temperature meets the long-term stable operation requirements during fast reactor operation.

[0008] The inventors of this application discovered that if all the coolant used to cool the pump support enters the hot pool or the cold pool, it can easily cause large temperature differences between the hot pool and the cold pool, which can adversely affect the structural materials within the hot pool or the cold pool. Therefore, the fast reactor provided in the embodiments of this application avoids large temperature differences between the hot pool and the cold pool caused by the coolant flowing out of the pump support cooling channel returning to both the hot pool and the cold pool simultaneously, thereby avoiding adverse effects on the structural materials and improving the safety of the fast reactor.

[0009] Secondly, embodiments of this application provide a method for cooling a pump support of a pool-type liquid metal cooled fast reactor, comprising: S1, providing a first cylinder and a second cylinder on the radially outer side of the pump support to form an upward flow channel between the pump support and the second cylinder and a downward flow channel between the first cylinder and the second cylinder; S2, using a flow distribution assembly to lead out a portion of the coolant into the upward flow channel, wherein the portion of the coolant can enter the upward flow channel to cool the pump support, and after cooling, flows through the downward flow channel back to the cold pool and the hot pool.

[0010] The cooling method provided in this application involves setting a first cylinder and a second cylinder on the radially outer side of the pump support to form an upward flow channel between the pump support and the second cylinder, and a downward flow channel between the first cylinder and the second cylinder. By using a flow distribution assembly to lead a portion of the coolant into the upward flow channel, this coolant can enter the upward flow channel to cool the pump support. After cooling, it flows back to the cold pool and hot pool through the downward flow channel. This fully utilizes the existing pumps and flow channels within the fast reactor to provide coolant to the upward flow channel for cooling the pump support. Without significantly increasing the complexity of the primary loop flow channels, pool-type liquid metal cooling of the fast reactor pump support is achieved, ensuring that the pump support temperature meets long-term stable operation requirements during fast reactor operation, and consequently, ensuring that the pump temperature meets long-term stable operation requirements during fast reactor operation. By returning the coolant flowing out from the downward flow channel to the hot pool and cold pool, large temperature differences in the hot pool or cold pool due to all coolant returning to either the hot pool or the cold pool are avoided, thus preventing adverse effects on structural materials and improving the safety of the fast reactor. Attached Figure Description

[0011] Other objects and advantages of this application will become apparent from the following description of embodiments of this application with reference to the accompanying drawings, and will help to provide a comprehensive understanding of this application.

[0012] Figure 1 This is a partial structural schematic diagram of a pool-type liquid metal cooled fast reactor provided in an embodiment of this application, showing the pump support and the pump support cooling component.

[0013] Explanation of reference numerals in the attached figures: 100. Fast reactor; 10. Main container; 101. Hot pool; 102. Cold pool; 20. Hot and cold pool partition; 201. First coolant outlet; 30. Pump; 41. Connecting pipeline; 410. Pump support coolant inlet; 42. Inlet throttling device; 50. Pump support; 501. Coolant inlet; 60. Pump support cooling components; 601. Pump support cooling channel; 6011. Rising channel; 6012. Falling channel; 61. Coolant inlet pipe; 62. First cylinder; 620. Second coolant outlet; 63. Second cylinder; 631. First overflow hole; 632. Second overflow hole; 64. Connecting ring; 65. First outlet throttling device; 66. Second outlet throttling device.

[0014] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are shown only in a schematic manner without affecting the reader's understanding. Detailed Implementation

[0015] Exemplary embodiments of this application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the development of any such actual embodiment to achieve the developer's specific goals, such as complying with constraints related to the system and business, and these constraints may vary depending on the implementation. Furthermore, it should be understood that while development work can be very complex and time-consuming, such development work is merely a routine task for those skilled in the art who benefit from the content of this application.

[0016] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the equipment structure and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0017] The pump support is located in the hot pool formed by the main vessel. Since the temperature of the hot pool is high (the average temperature of the hot pool exceeds 500°C), the temperature of the pump support located in the hot pool will also exceed 500°C, which is not conducive to the long-term stable operation of the pump support. At the same time, the heat from the hot pool will also be transferred to the primary loop pump through the pump support, causing the temperature of the primary loop pump to rise, which is also not conducive to the long-term stable operation of the primary loop pump.

[0018] To address the aforementioned issues, embodiments of this application provide a pool-type liquid metal cooled fast reactor and a method for cooling the pump support of the pool-type liquid metal cooled fast reactor, thereby reducing the temperature of the pump support and consequently reducing the temperature of the pump supported by the pump support, ensuring long-term stable operation of the pump support and the pump.

[0019] See Figure 1 , Figure 1 This is a partial structural schematic diagram of a pool-type liquid metal cooled fast reactor provided in an embodiment of this application. The figure shows the pump support and the pump support cooling components. Figure 1 The arrows in the figure indicate the direction of coolant flow. The fast reactor 100 provided in the embodiments of this application may include a main vessel 10, a hot and cold pool partition 20, a core assembly (not shown in the figure), a heat exchanger (not shown in the figure), a pump 30, a flow distribution assembly, a pump support 50, and a pump support cooling component 60. The main container 10 contains coolant; a hot and cold pool separator 20 is used to divide the main container 10 into a hot pool 101 and a cold pool 102; a core assembly is disposed within the main container 10, and the coolant in the cold pool 102 flows through the core assembly and then into the hot pool 101; a heat exchanger is used to cool the coolant in the hot pool 101 and then allow it to enter the cold pool 102; a pump 30 is used to pump the coolant in the cold pool 102 to a flow distribution assembly, which is used to distribute the coolant to the core assembly; a pump support 50 is used to support the pump 30; a pump support cooling element 60 is configured to form a pump support cooling channel 601 on the radially outer side of the pump support 50 for cooling the pump support 50; the flow distribution assembly is also used to distribute the coolant into the pump support cooling channel 601; the pump support cooling element 60 is also configured to allow the coolant flowing out of the pump support cooling channel 601 to return to the hot pool 101 and the cold pool 102.

[0020] The fast reactor 100 provided in the embodiments of this application forms a pump support cooling channel 601 by setting a pump support cooling component 60. The coolant in the cold pool 102 is pumped to the flow distribution assembly by the pump 30, and the coolant is distributed to the core assembly and the pump support cooling channel 601 by the flow distribution assembly. This allows the existing pump 30 and flow channels in the fast reactor 100 to provide coolant to the pump support cooling channel 601 to cool the pump support 50. Without significantly increasing the complexity of the primary loop flow channels, the pool-type liquid metal cooling of the fast reactor pump support 50 is achieved, ensuring that the temperature of the pump support 50 meets the long-term stable operation requirements when the fast reactor 100 is running, and thus ensuring that the temperature of the pump 30 meets the long-term stable operation requirements when the fast reactor 100 is running.

[0021] The inventors of this application have discovered that if all the coolant used to cool the pump support 50 enters the hot pool 101 or the cold pool 102, it can easily cause large temperature differences in the hot pool 101 or the cold pool 102, which can have an adverse effect on the structural materials. Therefore, the fast reactor 100 provided in this application uses the pump support cooling component 60 to return the coolant flowing out of the pump support cooling channel 601 to the hot pool 101 and the cold pool 102, thereby avoiding large temperature differences in the hot pool 101 or the cold pool 102 caused by all the coolant returning to the hot pool 101 or the cold pool 102, thus avoiding adverse effects on the structural materials and improving the safety of the fast reactor 100.

[0022] The fast reactor 100 provided in the embodiments of this application can be a sodium-cooled fast reactor.

[0023] In some embodiments, the flow distribution assembly may include a grid header and a connecting pipe 41. The connecting pipe 41 connects the outlet of the pump 30 to the inlet of the grid header, and the grid header is provided with a core coolant inlet for coolant to flow into the core assembly. The connecting pipe 41 is provided with a pump support coolant inlet 410 for coolant to flow into the pump support cooling channel 601. In such an embodiment, both the grid header and the connecting pipe 41 are existing structures within the reactor. By providing the pump support coolant inlet 410 in the connecting pipe 41, coolant can be distributed to the pump support cooling channel 601.

[0024] See Figure 1In some embodiments, the flow distribution assembly may further include an inlet throttling element 42 disposed at the pump support coolant inlet 410 to regulate the flow rate of coolant entering the pump support cooling channel 601, so that the temperature of the pump support 50 is less than or equal to a threshold. In such an embodiment, by providing an inlet throttling element 42 at the pump support coolant inlet 410 to regulate the flow rate of coolant entering the pump support cooling channel 601, sufficient cooling of the pump support 50 can be ensured to guarantee that its temperature is less than or equal to the threshold, and the flow rate of coolant flowing to the core assembly can also be guaranteed, thereby ensuring sufficient cooling of the core assembly.

[0025] The inlet pressure of the pump support cooling channel 601 is the fluid pressure at the outlet of the pump 30. The two outlet pressures of the pump support cooling channel 601 are the coolant pressures at the corresponding heights of the hot pool 101 and the cold pool 102, respectively. Therefore, the total pressure drop of the entire pump support cooling channel 601 is known. Since most of the pressure drop (≥95%) of the pump support cooling channel 601 is concentrated on the inlet throttling element 42, precise control of the flow rate entering the pump support cooling channel 601 can be achieved by controlling the resistance coefficient of the inlet throttling element 42.

[0026] See Figure 1 In some embodiments, the pump support cooling component 60 may include a coolant inlet 61, a first cylinder 62, and a second cylinder 63. The coolant inlet 61 is connected to the connecting pipe 41 to introduce coolant from the connecting pipe 41 into the coolant inlet 61. The first cylinder 62 and the second cylinder 63 are disposed radially outside the pump support 50, with the first cylinder 62 located radially outside the second cylinder 63. The pump support cooling channel 601 may include an ascending channel 6011 located between the second cylinder 63 and the pump support 50, and a descending channel 6012 located between the first cylinder 62 and the second cylinder 63. The coolant inlet 61 is connected to the ascending channel 6011, and the coolant in the coolant inlet 61 enters the ascending channel 6011 to cool the pump support 50 before flowing into the descending channel 6012. In such an embodiment, the above arrangement allows the coolant to flow in the rising channel 6011 located between the second cylinder 63 and the pump support 50, thereby carrying away the heat of the pump support 50 and cooling the pump support 50; since the falling channel 6012 is located between the first cylinder 62 and the second cylinder 63, it can prevent the heat of the hot pool 101 from being conducted to the pump support 50.

[0027] In some embodiments, coolant flowing out of the downflow channel 6012 is returned to the hot pool 101 and the cold pool 102.

[0028] In some embodiments, the pump support 50 is provided with a coolant inlet 501 for communication with a coolant connector 61. In such an embodiment, by providing the coolant inlet 501 communicating with the coolant connector 61, coolant can flow into the rising channel 6011 between the pump support 50 and the second cylinder 63 to cool the pump support 50.

[0029] In some embodiments, the lower end of the first cylinder 62 is connected to the hot and cold pool partition 20, and the lower end of the second cylinder 63 is spaced apart from the hot and cold pool partition 20. The pump support cooling component 60 may further include a connecting ring 64, which is spaced apart from the hot and cold pool partition 20 and connects the lower end of the second cylinder 63 to the pump support 50. The coolant inlet 501 is located above the connecting ring 64. The hot and cold pool partition 20 is provided with a first coolant outlet 201 for returning coolant in the downflow channel 6012 to the cold pool 102. The first coolant outlet 201 is configured to regulate the flow rate of coolant entering the cold pool 102. In this embodiment, by creating a gap between the lower end of the second cylinder 63 and the hot and cold pool partition 20, and by providing a connecting ring 64, a relatively spacious space can be formed at the bottom of the descending flow channel 6012. This not only helps to make the ascending flow channel 6011 and the descending flow channel 6012 narrower, thereby reducing the impact on the structure of the fast reactor 100, but also avoids the difficulty of setting the first coolant outlet 201 in the hot and cold pool partition 20 due to the ascending flow channel 6011 and the descending flow channel 6012 being too narrow.

[0030] In some embodiments, a second coolant outlet 620 is provided at the lower end of the first cylinder 62 for returning coolant in the downflow channel 6012 to the hot pool 101; the second coolant outlet 620 is configured to regulate the flow rate of coolant entering the hot pool 101. In such an embodiment, the above configuration enables the coolant in the downflow channel 6012 to cool the hot and cold pool separator 20 when returning to the hot pool 101, thereby reducing the temperature of the hot and cold pool separator 20 and improving its service life.

[0031] Furthermore, as mentioned above, since a relatively spacious space can be formed at the bottom of the downflow channel 6012, the first coolant outlet 201 and the second coolant outlet 620 are both connected to this space, which facilitates the flow of coolant in the downflow channel 6012 into the second coolant outlet 620 and the first coolant outlet 201.

[0032] In some embodiments, the first coolant outlet 201 and the second coolant outlet 620 may be configured such that the liquid level of the rising flow channel 6011 and the liquid level of the falling flow channel 6012 are higher than the liquid level of the hot pool 101, so as to improve the heat insulation effect of the rising flow channel 6011 and the falling flow channel 6012, reduce the heat transfer from the hot pool 101 to the pump support 50, and facilitate the cooling of the pump support 50.

[0033] In some embodiments, the first coolant outlet 201 and the second coolant outlet 620 may be configured such that the coolant flow rate into the hot pool 101 is less than the coolant flow rate into the cold pool 102. Since the temperature of the coolant flowing out from the downflow channel 6012 is closer to the temperature of the cold pool 102, making the coolant flow rate into the hot pool 101 less than the coolant flow rate into the cold pool 102 helps to avoid large temperature changes in the hot pool 101.

[0034] Due to the pressure drop, the liquid level in the rising channel 6011 is higher than the liquid level in the falling channel 6012.

[0035] In some embodiments, the liquid level of the downflow channel 6012 is set to be slightly higher than the liquid level of the hot pool 101 by 20-30 mm to reduce heat transfer from the hot pool 101 to the pump support 50.

[0036] In some embodiments, at least two-thirds of the coolant flowing out of the downflow channel 6012 is returned to the cold pool 102, and the remaining coolant is returned to the hot pool 101. Since the temperature of the coolant flowing out of the downflow channel 6012 is closer to the temperature of the cold pool 102, the embodiments of this application, by returning at least two-thirds of the coolant to the cold pool 102, can both cool the hot and cold pool separator 20 and reduce thermal fatigue of the structural materials of the fast reactor 100 due to temperature fluctuations, thus improving the service life of the structural materials of the fast reactor 100.

[0037] In some embodiments, the opening sizes of the first coolant outlet 201 and the second coolant outlet 620 can be determined based on the flow ratio of coolant returning to the hot pool 101 and coolant returning to the cold pool 102, as well as the resistance coefficients of the first coolant outlet 201 and the second coolant outlet 620, so that the flow rate of coolant returning to the cold pool 102 through the first coolant outlet 201 and the flow rate returning to the hot pool 101 through the second coolant outlet 620 satisfy the aforementioned ratio; at the same time, it also enables the first coolant outlet 201 and the second coolant outlet 620 to act as throttling devices, thereby eliminating the need to install throttling devices at the first coolant outlet 201 and the second coolant outlet 620, which helps to avoid increasing the system complexity of the fast reactor 100.

[0038] In some embodiments, a first outlet throttling element 65 and a second outlet throttling element 66 may be provided at the first coolant outlet 201 and the second coolant outlet 620, respectively, so that the flow rate of coolant returning to the cold pool 102 through the first outlet throttling element 65 and the flow rate returning to the hot pool 101 through the second outlet throttling element 66 also meet the above ratio.

[0039] In some embodiments, the pressure drops of the first outlet throttling element 65 and the second outlet throttling element 66 are different, and their pressure drops can be determined by calculation respectively.

[0040] In some embodiments, precise control of the coolant level in the downflow channel 6012 can be achieved by controlling the resistance coefficients of the first outlet throttling element 65 and the second outlet throttling element 66. The pressure drop of the first outlet throttling element 65 and the second outlet throttling element 66 determines the level difference between the downflow channel 6012 and the cold pool 102 and the hot pool 101. Since the levels of the hot pool 101 and the cold pool 102 are fixed, precise control of the coolant level in the downflow channel 6012 can be achieved by controlling the resistance coefficients of the first outlet throttling element 65 and the second outlet throttling element 66.

[0041] In some embodiments, the inlet throttling element 42 can be configured to determine the flow rate of coolant entering the pump support cooling channel 601 based on the heat transfer from the hot pool 101 to the pump support cooling channel 601, the inlet temperature of the pump support cooling channel 601, and the outlet temperature of the pump support cooling channel 601. In such an embodiment, the flow rate of coolant entering the pump support cooling channel 601 can be controlled by the inlet throttling element 42, thereby effectively cooling the pump support 50 to ensure its temperature meets requirements.

[0042] In some embodiments, the inlet temperature of the pump support cooling channel 601 can be approximated as the temperature of the coolant at the inlet of the flow distribution assembly, i.e., the temperature at the inlet of the core assembly, which is a known value.

[0043] In some embodiments, the second cylinder 63 may form a plurality of first overflow holes 631 and a plurality of second overflow holes 632 located below the plurality of first overflow holes 631; the first overflow holes 631 may be used to allow coolant in the rising flow channel 6011 to flow into the falling flow channel 6012 when the fast reactor is operating at rated power; the second overflow holes 632 may be used to allow coolant in the rising flow channel 6011 to flow into the falling flow channel 6012 when the fast reactor is in normal shutdown conditions (including refueling shutdown conditions and maintenance shutdown conditions).

[0044] In this embodiment, by providing a first overflow hole 631 and a second overflow hole 632, the rising flow channel 6011 and the falling flow channel 6012 can cool the pump support 50 when the fast reactor is running at rated power. During normal fast reactor shutdown, since the pump continues to run even when the reactor is shut down, the power of the pump 30 is lower than the rated power, and the coolant levels in both the rising flow channel 6011 and the falling flow channel 6012 drop, both falling below the first overflow hole 631. The coolant in the rising flow channel 6011 can only flow into the falling flow channel 6012 through the second overflow hole 632. Thus, even during normal fast reactor shutdown, the flow of coolant in the rising flow channel 6011 and the falling flow channel 6012 can be guaranteed, avoiding the formation of dead zones in the rising flow channel 6011 and the falling flow channel 6012, which would cause impurity deposition.

[0045] In some embodiments, the second overflow orifice 632 can also be used to allow coolant in the downflow channel 6012 to flow into the upflow channel 6011 during natural circulation operation. Since the pump 30 stops driving coolant flow during natural circulation, the coolant levels in both the upflow channel 6011 and the downflow channel 6012 decrease. Furthermore, the temperature of the hot pool 101 is higher than the pump chamber temperature of the pump 30. Therefore, the coolant level in the downflow channel 6012, which is closer to the hot pool 101, is higher than the level in the upflow channel 6011. The coolant in the downflow channel 6012 can flow to the upflow channel 6011 through the second overflow orifice 632, thus forming a natural circulation channel. This prevents the coolant in the pump support cooling channel 601 from becoming stagnant, thereby preventing impurities from depositing and clogging the pump support cooling channel 601. Simultaneously, the hot pool 101 and the cold pool 102 can be connected through the first coolant outlet 201 and the second coolant outlet 620, which is beneficial for uniform coolant temperature within the fast reactor 100.

[0046] In some embodiments, the height of the first overflow orifice 631 may be the same as the liquid level height of the hot pool 101 during rated operation of the fast reactor, and the orifice diameter of the first overflow orifice 631 may be larger than the orifice diameter of the second overflow orifice 632, so that most of the coolant in the rising channel 6011 flows into the falling channel 6012 through the first overflow orifice 631, so as to better cool the pump support 50.

[0047] In some embodiments, the height of the second overflow orifice 632 is lower than the liquid level of the hot pool 101 under normal shutdown conditions of the fast reactor, so as to ensure that the coolant in the rising channel 6011 can flow into the falling channel 6012 through the second overflow orifice 632 under normal shutdown conditions.

[0048] In some embodiments, the coolant level in the rising channel 6011 under different operating conditions can be precisely controlled by the resistance coefficients of the first overflow orifice 631 and the second overflow orifice 632. Since the pressure drop of the first overflow orifice 631 and the second overflow orifice 632 can determine the level difference between the rising channel 6011 and the falling channel 6012 under different operating conditions, the coolant level in the rising channel 6011 under different operating conditions can be further precisely controlled by controlling the resistance coefficients of the first overflow orifice 631 and the second overflow orifice 632.

[0049] In some embodiments, a plurality of second overflow holes 632 may be arranged horizontally spaced below the first overflow hole 631.

[0050] Embodiments of this application also provide a method for cooling the pump support of a pool-type liquid metal cooled fast reactor (hereinafter referred to as the cooling method), which may include: S1, providing a first cylinder 62 and a second cylinder 63 on the radially outer side of the pump support 50 to form an upward flow channel 6011 between the pump support 50 and the second cylinder 63 and a downward flow channel 6012 between the first cylinder 62 and the second cylinder 63; S2, using a flow distribution assembly to lead out a portion of the coolant to the upward flow channel 6011, wherein the portion of the coolant can enter the upward flow channel 6011 to cool the pump support 50, and after cooling, flows through the downward flow channel 6012 back to the cold pool 102 and the hot pool 101.

[0051] The cooling method provided in the embodiments of this application involves setting a first cylinder 62 and a second cylinder 63 on the radially outer side of the pump support 50 to form an upward flow channel 6011 between the pump support 50 and the second cylinder 63 and a downward flow channel 6012 between the first cylinder 62 and the second cylinder 63. By using a flow distribution assembly to lead out a portion of the coolant to the upward flow channel 6011, this portion of coolant can enter the upward flow channel 6011 to cool the pump support 50, and after cooling, it flows through the downward flow channel 6012 back to the cold pool 102 and the hot pool 101. This fully utilizes the existing pumps 30 and flow channels within the fast reactor 100 to provide coolant to the upward flow channel 6011 to cool the pump support 50. Without significantly increasing the complexity of the primary loop flow channels, it achieves cooling of the pool-type liquid metal cooled fast reactor pump support, ensuring that the pump support temperature meets the long-term stable operation requirements during fast reactor operation, and thus ensuring that the pump temperature meets the long-term stable operation requirements during fast reactor operation. By returning the coolant flowing out of the downflow channel 6012 to the hot pool 101 and the cold pool 102, the large temperature difference change in the hot pool 101 or the cold pool 102 caused by all the coolant returning to the hot pool 101 or the cold pool 102 is avoided, thereby avoiding adverse effects on the structural materials and improving the safety of the fast reactor 100.

[0052] In some embodiments, the flow rate of coolant entering the rising flow channel 6011 is determined based on the heat transfer from the hot pool 101 to the descending flow channel 6012, the inlet temperature of the rising flow channel 6011, and the outlet temperature of the descending flow channel 6012. In such embodiments, it is advantageous to quickly and accurately determine the flow rate of coolant entering the rising flow channel 6011.

[0053] In some embodiments, the outlet temperature of the downflow channel 6012 can be determined based on the temperature of the cold pool 102 and the structural material of the in-core support. The structural material of the in-core support within the cold pool 102 has a certain temperature difference limit. When the outlet coolant temperature of the downflow channel 6012 is too high, the temperature difference change in the cold pool 102 will exceed the temperature difference limit that the structural material of the in-core support can withstand, thereby causing damage to the structural material of the in-core support and affecting the safety of the core assembly. The embodiments of this application, by determining the outlet temperature of the downflow channel 6012 based on the temperature of the cold pool 102 and the structural material of the in-core support, help to reduce the adverse effects on the in-core support.

[0054] In some embodiments, the temperature difference limit between the outlet temperature of the downflow channel 6012 and the temperature of the cold pool 102 can be determined based on the performance of the structural material of the in-core support. The outlet temperature of the downflow channel 6012 can be determined based on the temperature difference limit, thereby avoiding damage to the structural material of the in-core support and avoiding affecting the safety of the core assembly.

[0055] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0056] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A pool-type liquid metal cooled fast reactor, characterized in that, include: The main container, which contains the coolant; A hot and cold pool separator is used to divide the main container into a hot pool and a cold pool; The core assembly is disposed inside the main container, and the coolant in the cold pool flows through the core assembly and then into the hot pool; A heat exchanger is used to cool the coolant in the hot pool and then allow it to enter the cold pool; A pump and a flow distribution assembly, wherein the pump is used to pump coolant from the cold pool to the flow distribution assembly, and the flow distribution assembly is used to distribute coolant to the core assembly; Pump support, used to support the pump; A pump support cooling component is configured to form a pump support cooling channel on the radially outer side of the pump support for cooling the pump support; The flow distribution component is also used to distribute coolant into the pump support cooling channel; The pump support cooling element is further configured such that coolant flowing out of the pump support cooling channel returns to the hot pool and the cold pool.

2. The fast reactor according to claim 1, characterized in that, The traffic allocation component includes: A grid header and connecting piping, the connecting piping being used to connect the outlet of the pump to the inlet of the grid header, the grid header being provided with a core coolant inlet for allowing coolant to flow into the core assembly; The connecting pipeline is provided with a pump support coolant inlet for supplying coolant into the pump support cooling channel.

3. The fast reactor according to claim 2, characterized in that, The traffic allocation component also includes: An inlet throttling element is installed at the coolant inlet of the pump support to regulate the flow rate of coolant entering the cooling channel of the pump support, so that the temperature of the pump support is less than or equal to a threshold.

4. The fast reactor according to claim 2, characterized in that, The pump support cooling component includes: A coolant connector is provided for connection to the connecting pipe to introduce coolant from the connecting pipe into the coolant connector. The first cylinder and the second cylinder are disposed radially outside the pump support, and the first cylinder is located radially outside the second cylinder; The pump support cooling channel includes an ascending channel located between the second cylinder and the pump support, and a descending channel located between the first cylinder and the second cylinder; The coolant inlet pipe is connected to the rising flow channel, and the coolant in the coolant inlet pipe enters the rising flow channel to cool the pump support before flowing into the falling flow channel.

5. The fast reactor according to claim 4, characterized in that, The pump support is provided with a coolant inlet for connection to the coolant pipe.

6. The fast reactor according to claim 5, characterized in that, The lower end of the first cylindrical component is connected to the hot and cold pool partition, and the lower end of the second cylindrical component forms a gap with the hot and cold pool partition. The pump support cooling component further includes: a connecting ring, which is spaced apart from the hot and cold pool separator and connects the lower end of the second cylinder to the pump support, with the coolant inlet located above the connecting ring; The hot and cold pool separator is provided with a first coolant outlet for returning the coolant in the descending flow channel to the cold pool; The first coolant outlet is configured to regulate the flow rate of coolant entering the cold pool.

7. The fast reactor according to claim 6, characterized in that, The lower end of the first cylinder is provided with a second coolant outlet for returning the coolant in the descending flow channel to the hot pool; The second coolant outlet is configured to regulate the flow rate of coolant entering the hot pool.

8. The fast reactor according to claim 7, characterized in that, The first coolant outlet and the second coolant outlet are configured such that the liquid level in the rising channel and the liquid level in the falling channel are higher than the liquid level in the hot pool.

9. The fast reactor according to claim 7, characterized in that, The first coolant outlet and the second coolant outlet are configured such that the coolant flow rate into the hot pool is less than the coolant flow rate into the cold pool.

10. The fast reactor according to claim 3, characterized in that, The inlet throttling device is configured to determine the flow rate of coolant entering the pump support cooling channel based on the heat transfer from the hot pool to the pump support cooling channel, the inlet temperature of the pump support cooling channel, and the outlet temperature of the pump support cooling channel.

11. The fast reactor according to claim 6, characterized in that, The second cylindrical component forms a plurality of first overflow holes and a plurality of second overflow holes located below the plurality of first overflow holes; The first overflow orifice is used to allow coolant in the rising channel to flow into the falling channel when the fast reactor is operating at rated power; The second overflow orifice is used to allow coolant in the rising channel to flow into the falling channel during normal fast reactor shutdown.

12. A method for cooling the pump support of a pool-type liquid metal cooled fast reactor, characterized in that, include: S1. A first cylinder and a second cylinder are provided on the radially outer side of the pump support to form an upward flow channel between the pump support and the second cylinder and a downward flow channel between the first cylinder and the second cylinder; S2. Using the flow distribution component, a portion of the coolant is drawn out to the rising flow channel. The coolant can enter the rising flow channel to cool the pump support, and after cooling, it flows through the falling flow channel back to the cold pool and the hot pool.

13. The method according to claim 12, characterized in that, The flow rate of coolant entering the rising channel is determined based on the heat transfer from the hot pool to the descending channel, the inlet temperature of the rising channel, and the outlet temperature of the descending channel.

14. The method according to claim 12, characterized in that, The outlet temperature of the descending channel is determined based on the cold pool temperature and the structural material of the in-pile support.

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