Nuclear main pump motor and liquid level detection device for lubricating oil in bearing chamber of nuclear main pump motor

Abstract

The utility model belongs to the technical field of nuclear industry, and particularly relates to a nuclear main pump motor and a liquid level detection device for lubricating oil of a bearing chamber of the nuclear main pump motor, the liquid level detection device comprises a shell and a liquid level detection assembly, the shell is provided with a containing cavity, and the inner side wall, facing the containing cavity, of the shell is provided with a shielding part; the liquid level monitoring module of the liquid level detection assembly is installed in the containing cavity, and the shielding part surrounds the containing cavity, so that the shielding part can effectively prevent external nuclear radiation from entering the containing cavity, the influence of the nuclear radiation on electronic components such as the liquid level monitoring module is reduced, and normal work of the liquid level detection device is ensured; according to the liquid level detection device, the liquid level measurement precision of the liquid level monitoring module and the accuracy of liquid level information signal transmission are improved, meanwhile, the risk that the structure of the liquid level monitoring module is damaged by nuclear radiation can be reduced through the arrangement of the shielding part, the maintenance frequency of the liquid level monitoring module is reduced, the service life of the liquid level monitoring module is prolonged, and therefore the practicability of the liquid level detection device is overall improved.

Description

Technical Field

[0001] This application belongs to the field of nuclear industry technology, and more specifically, it relates to a liquid level detection device for the lubricating oil in the bearing chamber of a nuclear main pump motor. Background Technology

[0002] The reactor coolant pump in the primary loop system of a nuclear power plant, also known as the main nuclear pump, is a key piece of equipment in the primary loop system. Its main function is to drive the reactor coolant to circulate in the primary loop system. After the coolant absorbs heat in the reactor core, it is driven by the coolant pump to transfer the heat to the steam generator, which in turn transfers the heat to the water in the secondary loop to generate steam for power generation.

[0003] A nuclear main pump typically consists of a pump casing, impeller, pump shaft, motor, and sealing devices. The motor is the core power component driving the main pump, and its reliable operation directly determines the pump's reliability. To ensure the high-speed operation of the motor, proper lubrication of the motor bearings is essential. The main pump motor has upper and lower bearing chambers, containing 760L and 110L of lubricating oil respectively. During operation, the lubricating oil level needs to be monitored in real time to ensure it remains within acceptable limits.

[0004] In related technologies, common lubricating oil level detection devices typically use electronic components such as level gauges to measure the liquid level. However, due to the long-term use of these devices in environments with high doses of nuclear radiation, the electronic components inside are easily affected by nuclear radiation, leading to inaccurate measurement results. This, in turn, affects the system's accurate assessment of the reliability of the nuclear main pump motor. Furthermore, components exposed to radiation for extended periods are prone to failure, resulting in a shortened normal service life for the detection device, requiring frequent maintenance or replacement, and thus low practicality. Utility Model Content

[0005] The purpose of this application is to provide a liquid level detection device for the lubricating oil in the main pump motor and its bearing chamber, so as to solve the technical problems of low measurement accuracy, short service life and frequent replacement of the lubricating oil level detection device in the nuclear radiation environment.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0007] A device for detecting the level of lubricating oil in the bearing chamber of a nuclear main pump motor is provided, comprising:

[0008] The housing is used to mount the motor to the nuclear main pump; the interior of the housing is hollow and forms a receiving cavity.

[0009] The liquid level detection assembly includes a float, a connecting rod, and a liquid level monitoring module. The liquid level monitoring module is installed in a receiving cavity. One end of the connecting rod is located in the receiving cavity and is connected to the trigger element of the liquid level monitoring module. The other end of the connecting rod extends out of the housing and is connected to the float. The float is used to be placed in the lubricating oil in the bearing cavity of the motor. The liquid level monitoring module is used to detect the liquid level height of the lubricating oil according to the floating of the float and transmit the detected liquid level height information to the outside.

[0010] The outer shell also includes a shielding part, which is located at least on the inner wall of the outer shell facing the cavity, and surrounds the cavity to shield against external nuclear radiation.

[0011] In some embodiments, the shielding portion is a lead material portion or a concrete material portion.

[0012] In some embodiments, the thickness of the shielding portion is 0.5cm to 5cm in the direction from the inside to the outside of the receiving cavity.

[0013] In some embodiments, along the axial direction of the connecting rod, the end of the housing facing the float has an opening, the housing is detachably connected to a base, the base is adapted to cover the opening of the housing, the connecting rod passes through the base, and the inner wall of the housing facing the receiving cavity and the inner wall of the base facing the receiving cavity both have shielding portions.

[0014] In some embodiments, the outer casing is a stainless steel casing, the base is a stainless steel base, and the shielding portion includes a shielding layer attached to the inner sidewall of the outer casing and the inner sidewall of the base.

[0015] In some embodiments, the lubricating oil level detection device for the bearing chamber of the nuclear main pump motor further includes a temperature detection component. The temperature detection component includes a temperature sensor and a temperature transmission module. The temperature sensor is installed on a float and can be placed in the lubricating oil along with the float to detect the temperature of the lubricating oil. The temperature transmission module is installed in the receiving cavity. The temperature sensor and the temperature transmission module are electrically connected. The temperature transmission module is used to receive and transmit the temperature information detected by the temperature sensor to the outside.

[0016] In some embodiments, the float has a heat-conducting part on at least the side away from the connecting rod, and a temperature sensor is installed inside the float and thermally connected to the heat-conducting part. The temperature sensor detects the temperature of the lubricating oil by detecting the temperature of the heat-conducting part.

[0017] Alternatively, the float may have a through hole on the side away from the connecting rod. The temperature sensor includes a main body and a temperature probe. The main body is installed inside the float, and the temperature probe is sealed and inserted into the through hole. The end of the temperature probe away from the main body protrudes through the through hole for insertion into the lubricating oil.

[0018] In some embodiments, the float is a metal ball.

[0019] In some embodiments, the temperature sensor is a platinum resistance sensor.

[0020] This application also provides a nuclear main pump motor, including a motor host and the above-mentioned nuclear main pump motor bearing chamber lubricating oil level detection device. The motor host has a bearing chamber containing lubricating oil, and the level detection device is detachably installed on the motor host.

[0021] The housing of the liquid level detection device is located outside the bearing chamber. Along the height direction of the lubricating oil, one end of the connecting rod connected to the float slides through the chamber wall of the bearing chamber and extends into the bearing chamber, with the float immersed in the lubricating oil.

[0022] The beneficial effects of the lubricating oil level detection device for the bearing chamber of the nuclear main pump motor provided in this application are as follows: The lubricating oil level detection device mainly includes a housing and a lubricating oil level detection component. The housing is used to install on the motor of the nuclear main pump and has a hollow receiving cavity inside. The lubricating oil level detection component includes a float, a connecting rod, and a lubricating oil level monitoring module. The lubricating oil level monitoring module is installed in the receiving cavity and connected to the float through the connecting rod. The float can be immersed in the lubricating oil in the bearing chamber of the motor, so that the lubricating oil level detection component can sense the lubricating oil level through the float and then transmit it to the lubricating oil level monitoring module through the connecting rod, thereby realizing the detection of the lubricating oil level. Since the main nuclear pump is located in a nuclear radiation environment, a shielding part is installed on the inner wall of the outer shell facing the containment cavity. The shielding part surrounds the containment cavity and effectively blocks external nuclear radiation from entering the containment cavity. This reduces the impact of nuclear radiation on electronic components such as the liquid level monitoring module, ensures the normal operation of the liquid level detection device, improves the liquid level measurement accuracy of the liquid level monitoring module and the accuracy of liquid level information signal transmission. At the same time, the shielding part also reduces the risk of nuclear radiation damaging the structure of the liquid level monitoring module, helps to reduce the maintenance frequency of the liquid level monitoring module, extends its service life, and thus improves the overall practicality of the liquid level detection device. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the structure of the lubricating oil level detection device for the bearing chamber of the nuclear main pump motor provided in this embodiment of the application;

[0025] Figure 2 for Figure 1 A cross-sectional view of the liquid level detection device shown;

[0026] Figure 3A cross-sectional view of a lubricating oil level detection device for the bearing chamber of a nuclear main pump motor, provided in another embodiment.

[0027] The following are the labeling elements in the figure:

[0028] 10. Outer shell; 11. Receiving cavity; 12. Shielding part; 121. Shielding layer; 13. Base; 14. Handle;

[0029] 20. Liquid level detection component; 21. Float; 211. Through hole; 22. Connecting rod; 23. Liquid level monitoring module; 30. Temperature detection component; 31. Temperature sensor; 311. Main body; 312. Temperature probe; 32. Temperature transmission module; 40. Mounting plate. Detailed Implementation

[0030] To make the technical problem to be solved, the technical solution and the beneficial effects of this application clearer, the following is in conjunction with the appendix. Figures 1 to 3 The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

[0031] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0032] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, "multiple sets" means two or more sets, "multiple pieces" means two or more pieces, and "several" means one or more, unless otherwise explicitly specified.

[0034] The reactor coolant pump in the primary loop system of a nuclear power plant, also known as the main nuclear pump, is a key piece of equipment in the primary loop system. Its main function is to drive the reactor coolant to circulate in the primary loop system. After the coolant absorbs heat in the reactor core, it is driven by the coolant pump to transfer the heat to the steam generator, which in turn transfers the heat to the water in the secondary loop to generate steam for power generation.

[0035] A nuclear main pump typically consists of a pump casing, impeller, pump shaft, motor, and sealing devices. The motor is the core power component driving the main pump, and its reliable operation directly determines the pump's reliability. To ensure the high-speed operation of the motor, proper lubrication of the motor bearings is essential. The main pump motor has upper and lower bearing chambers, containing 760L and 110L of lubricating oil respectively. During operation, the lubricating oil level needs to be monitored in real time to ensure it remains within acceptable limits.

[0036] In related technologies, common lubricating oil level detection devices typically use electronic components such as level gauges to measure the liquid level. However, since the main nuclear pump is primarily used to transport the primary coolant in the primary loop of a nuclear power plant, the coolant not only has high pressure and a high temperature of 290°C, but also high radioactivity. Nuclear radiation can cause the electronic components inside the detection device to malfunction. For example, nuclear radiation mainly includes alpha rays, beta rays, gamma rays, and neutron rays. These rays affect electronic components through various mechanisms. For instance, the interaction between nuclear radiation particles and matter in electronic components can ionize atoms, generating a large number of electron-hole pairs. These additional charge carriers can interfere with the normal operation of electronic components. For example, in semiconductor devices, this can alter the internal electric field distribution and current transport characteristics, causing the threshold voltage of transistors to drift, leakage current to increase, and ultimately leading to performance degradation or even complete failure of the component. Another example is the interaction between high-energy particles (such as neutrons) in nuclear radiation and atoms in electronic components. When atoms collide, they leave their original lattice positions, forming lattice defects. These defects affect the migration path of electrons, increase resistance, reduce the carrier mobility of electronic components, and may also cause changes in the characteristics of PN junctions in semiconductor devices, degrading the performance of components such as diodes and transistors, ultimately leading to the failure of electronic components. For example, for some electronic components with storage functions, such as flash memory chips, nuclear radiation may cause charge leakage or accumulation of trapped charges in their internal storage cells, leading to the loss or error of stored data. At the same time, radiation may also exacerbate electromigration in the metal interconnects of electronic components, causing open circuits or short circuits, making the electronic components unable to function properly.

[0037] Thus, if the detection device is used in an environment with high doses of nuclear radiation for a long time, the electronic components inside the detection device are easily interfered with by nuclear radiation, resulting in inaccurate measurement results. This affects the system's accurate judgment of the reliability of the nuclear main pump motor. Furthermore, components are also prone to failure due to long-term radiation exposure, which shortens the normal service life of the detection device and requires frequent maintenance or replacement, resulting in low practicality.

[0038] Based on this, this application provides a device for detecting the level of lubricating oil in the bearing chamber of a nuclear main pump motor to solve the above problems.

[0039] Please refer to the following: Figures 1 to 3 The lubricating oil level detection device for the bearing chamber of the nuclear main pump motor provided in this application embodiment is applicable, but not limited to, for real-time level detection of the lubricating oil in the bearing chamber of the reactor coolant pump, i.e., the nuclear main pump, in the primary loop system of the nuclear island.

[0040] In the embodiments of this application, such as Figures 1 to 3 As shown, the lubricating oil level detection device for the bearing chamber of the nuclear main pump motor includes a housing 10 and a level detection component 20. The housing 10 is used to install the motor of the nuclear main pump, and the interior of the housing 10 is hollow, forming a receiving cavity 11. The level detection component 20 includes a float 21, a connecting rod 22, and a level monitoring module 23. The level monitoring module 23 is installed in the receiving cavity 11. One end of the connecting rod 22 is located in the receiving cavity 11 and connected to the trigger element of the level monitoring module 23. The other end of the connecting rod 22 extends out of the housing 10 and is connected to the float 21. The float 21 is used to be placed in the lubricating oil in the bearing chamber of the motor. The level monitoring module 23 is used to detect the level of the lubricating oil according to the floating of the float 21 and transmit the detected level information to the outside. The housing 10 also includes a shielding part 12, which is at least located on the inner side wall of the housing 10 facing the receiving cavity 11. The shielding part 12 surrounds the receiving cavity 11 to shield against external nuclear radiation.

[0041] In this embodiment, the liquid level detection device includes a housing 10, which is a supporting structure for the entire liquid level detection device and is used to install it onto the motor of the nuclear main pump, so that the liquid level detection device can be installed as a whole on the motor. The interior of the housing 10 is hollow and forms a receiving cavity 11, which provides installation space for various electronic components, including the liquid level monitoring module 23 of the liquid level detection assembly 20.

[0042] In this embodiment, the liquid level detection device further includes a liquid level detection component 20, which specifically includes a float 21, a connecting rod 22, and a liquid level monitoring module 23. The float 21 can be placed in the lubricating oil within the bearing cavity of the motor. The float 21 floats up and down (in the direction shown by arrow F1 in the figure) with changes in the lubricating oil level due to buoyancy. The float 21 is connected to the trigger element of the liquid level monitoring module 23 via the connecting rod 22. When the float 21 floats with the lubricating oil level, the connecting rod 22 actuates the trigger element of the liquid level monitoring module 23. Thus, the liquid level monitoring module 23, installed in the receiving cavity 11, receives the position change information of the float 21 via the connecting rod 22, thereby detecting the lubricating oil level and transmitting the detected level information externally so that operators or related systems can obtain the liquid level data. This enables the liquid level monitoring module 23 to detect the lubricating oil level.

[0043] It should be noted that the liquid level monitoring module 23 refers to the component used to sense the changes in the float 21 as the lubricating oil level fluctuates. The liquid level monitoring module includes a trigger element, and one end of the connecting rod 22 is connected to the trigger element of the liquid level monitoring module. The connecting rod 22 can be directly or indirectly connected to the trigger element. The trigger element can be a reed switch or an electronic converter, etc. One end of the connecting rod 22 can be directly connected to the trigger element. The float 21 drives the connecting rod 22 to move, thereby driving the trigger element to move and completing the liquid level measurement. Alternatively, one end of the connecting rod 22 can also be connected to the trigger element through other adapters. The float 21 drives the connecting rod 22 to move, which in turn drives the adapter to move, further driving the trigger element to move and completing the liquid level measurement.

[0044] For example, the triggering element of the liquid level monitoring module 23 can be a reed switch. One end of the connecting rod 22 is connected to the float 21, and the other end of the connecting rod 22 is magnetically connected to the reed switch through a magnet. When the float 21 moves to the corresponding position, the magnet will attract the reed switch, causing the total resistance or voltage of the liquid level monitoring module 23 to change, thereby converting the change in liquid level into an electrical signal, thus realizing the detection of the lubricating oil level.

[0045] Based on this, the liquid level monitoring module 23 also includes a transmitter, which converts the electrical signal such as resistance or voltage output by the trigger element into a standard current signal such as 4mA-20mA or a voltage signal such as 0V-5V, and can transmit the signal outward to facilitate long-distance transmission and display of lubricating oil level information, thereby realizing remote monitoring of lubricating oil level.

[0046] In this embodiment, the outer casing 10 further includes a shielding portion 12, which is disposed on the inner wall of the outer casing 10 facing the receiving cavity 11 and arranged around the receiving cavity 11. The main function of the shielding portion 12 is to shield external nuclear radiation, reduce the risk of nuclear radiation entering the receiving cavity 11 and affecting the normal operation of components such as the liquid level monitoring module 23, and ensure that the liquid level detection device can operate accurately and stably in the strong radiation environment of the nuclear power plant. It can be understood that the shielding portion 12 refers to a structural part capable of shielding nuclear radiation, which can effectively block nuclear radiation rays including alpha rays, beta rays, gamma rays, and neutron rays. Exemplarily, the shielding portion 12 may be a lead layer or a lead isotope structural layer located inside the outer casing 10 and arranged around the receiving cavity 11, or it may be a concrete structural layer, or it may be a structural layer of lead or a mixture of lead isotopes and concrete.

[0047] The lubricating oil level detection device for the bearing chamber of the nuclear main pump motor according to this application embodiment mainly includes a housing 10 and a level detection component 20. The housing 10 is used to install on the motor of the nuclear main pump and has a hollow receiving cavity 11 inside. The level detection component 20 includes a float 21, a connecting rod 22 and a level monitoring module 23. The level monitoring module 23 is installed in the receiving cavity 11 and connected to the float 21 through the connecting rod 22. The float 21 can be immersed in the lubricating oil in the bearing chamber of the motor, so that the level detection component 20 can sense the lubricating oil level through the float 21 and then transmit it to the level monitoring module 23 through the connecting rod 22, thereby realizing the detection of the lubricating oil level. Since the main nuclear pump is located in a nuclear radiation environment, a shielding part 12 is provided on the inner wall of the outer shell 10 facing the receiving cavity 11. The shielding part 12 surrounds the receiving cavity 11, effectively blocking external nuclear radiation from entering the receiving cavity 11. This reduces the impact of nuclear radiation on electronic components such as the liquid level monitoring module 23, ensuring the normal operation of the liquid level detection device, improving the liquid level measurement accuracy and the accuracy of liquid level information signal transmission of the liquid level monitoring module 23. At the same time, the shielding part 12 also reduces the risk of nuclear radiation damaging the structure of the liquid level monitoring module 23, helping to reduce the maintenance frequency of the liquid level monitoring module 23 and extend its service life, thereby improving the overall practicality of the liquid level detection device.

[0048] In a specific embodiment, such as Figure 2 and Figure 3 As shown, the liquid level detection component 20 may also include an alarm module (not shown in the figure). The alarm module is communicatively connected to the liquid level monitoring module 23. When the liquid level of the lubricant reaches the lower or upper limit, the alarm module generates an alarm signal and can transmit the signal outward, thereby reminding the operator that the current liquid level of the lubricant has reached the limit (upper or lower limit) and needs to be dealt with.

[0049] For example, the normal level of the lubricating oil is used as the measurement reference point. 50mm below this reference point is defined as the lower limit of the lubricating oil level, and 50mm above it is defined as the upper limit. For instance, when the reference point is 200mm high, and the float 21 is at 200mm high, the level detection component 20 outputs a level of 200mm, and the alarm module does not generate an alarm signal. When the lubricating oil level decreases and the float 21 moves downwards to a height of 220mm, the level detection component 20 outputs a level of 220mm. At this point, the lubricating oil level has not reached its limit, and the alarm module does not generate an alarm signal. When the lubricating oil level decreases... As the lubricating oil level continues to decrease, when the float 21 moves downward to a height of 200mm, the level detection component 20 outputs a level of 200mm. At this point, the lubricating oil level has reached the lower limit, and the alarm module generates an alarm signal. When the lubricating oil level is too high, when the float 21 moves upward to a height of 280mm, the level detection component 20 outputs a level of 280mm. At this point, the lubricating oil level has not reached the limit, and the alarm module does not generate an alarm signal. However, when the lubricating oil level reaches a height of 300mm, the level detection component 20 outputs a level of 300mm. At this point, the lubricating oil level has reached the upper limit, and the alarm module generates an alarm signal simultaneously.

[0050] In some embodiments, such as Figures 1 to 3 As shown, a handle 14 and a mounting plate 40 may also be provided on the housing 10. The entire liquid level detection device can be moved by holding the handle 14, and the mounting plate 40 is detachably connected to the motor housing. For example, the handle 14 may be located at a position away from the top of the connecting rod 22 of the housing 10, and the mounting plate 40 may be located at a position on the bottom of the housing 10 facing the connecting rod 22.

[0051] In some embodiments, the shielding portion 12 is a lead material portion, a concrete material portion, or a mixture of concrete and lead material portion.

[0052] In this embodiment, the shielding part 12 is made of lead, concrete, or a mixture of lead and concrete. Lead has an atomic number of 82. This high atomic number allows lead to more effectively absorb radiation energy during photoelectric effects, Compton effects, and pair production with gamma rays. For example, in the photoelectric effect, the inner-shell electrons of lead atoms have a higher binding energy, making it easier to absorb photon energy from gamma rays, causing the photons to be absorbed rather than penetrate the material. Furthermore, lead has a density of approximately 11.34 g / cm³. This high density allows lead to provide more atoms to interact with radiation, increasing its ability to block radiation. When radiation propagates through lead material, the probability of colliding with lead atoms is higher, resulting in absorption or scattering and reducing the amount of radiation penetrating. As for concrete materials or mixtures of concrete and lead, ordinary concrete itself has a certain shielding ability against nuclear radiation. If heavy metal elements such as lead are added to the concrete mixture, the density can be further increased, thereby more effectively reducing the intensity of gamma rays. At the same time, concrete also contains substances such as hydrogen, boron, borides, and lithium salts, all of which have good absorption properties for neutrons, thus effectively shielding neutron rays.

[0053] In some embodiments, the thickness of the shielding portion 12 is 0.5cm to 5cm in the direction from the inside to the outside of the receiving cavity 11.

[0054] Among them, such as Figure 2 and Figure 3 As shown, the direction from the inside to the outside of the receiving cavity 11 is indicated by arrow F2 in the figure. Radiation rays need to penetrate the cavity wall of the receiving cavity 11 to reach the cavity 11. Therefore, by setting a shielding part 12 of the aforementioned thickness in the direction of ray penetration, effective shielding of radiation rays can be achieved. The thickness of the shielding part 12 from the inside to the outside of the receiving cavity 11 is set to 0.5cm~5cm to ensure that the shielding part 12 can effectively shield external nuclear radiation. This avoids the situation where the shielding part 12 is too thin and cannot sufficiently block nuclear radiation, causing radiation to enter the receiving cavity 11 and affect the normal operation of components such as the liquid level monitoring module. At the same time, it also avoids setting the shielding part 12 too thick, which would increase the overall size, weight, and cost of the liquid level detection device.

[0055] Understandably, gamma rays and other forms of nuclear radiation have strong penetrating power. Within the aforementioned range, the thicker the shielding portion 12, the longer the path the gamma rays travel within it, and the more opportunities they have to interact with the various atoms within the shielding portion 12. This results in a greater degree of absorption and scattering, and thus a better shielding effect. As for charged particles such as beta rays, beta particles will scatter as they move within the shielding portion 12. Within the aforementioned range, the thicker the shielding portion 12, the more times the beta particles are scattered within it. Their direction of motion constantly changes, and their energy is gradually lost, ultimately leading to effective blocking.

[0056] In a specific embodiment, the thickness of the shielding part 12, from the inside to the outside of the receiving cavity 11, can be 0.5cm, 0.8cm, 1.0cm, 1.5cm, 2.0cm, 2.5cm, 3.0cm, 3.2cm, 3.5cm, 4.0cm, 4.2cm, 4.5cm, 4.8cm, or 5cm, etc. The thickness of the shielding part 12 is not uniquely limited here, and can be specifically designed according to the intensity of radiation, etc.

[0057] In a specific embodiment, within the aforementioned thickness range, the thickness of the shielding portion 12 at various locations can be equal or unequal, in the direction from the inside to the outside of the receiving cavity 11.

[0058] In some embodiments, such as Figure 2 and Figure 3 As shown, along the axial direction of the connecting rod 22, the end of the outer shell 10 facing the float 21 has an opening. The outer shell 10 is detachably connected to the base 13, which is adapted to cover the opening of the outer shell 10. The connecting rod 22 passes through the base 13. The inner wall of the outer shell 10 facing the receiving cavity 11 and the inner wall of the base 13 facing the receiving cavity 11 both have shielding parts 12.

[0059] In this embodiment, the housing 10 has an opening along the axial direction of the connecting rod 22 (i.e., the direction indicated by arrow F1 in the figure). A base 13 is connected to the opening of the housing 10, and the base 13 closes the opening of the housing 10. Furthermore, the base 13 is detachably connected to the housing 10. During installation, maintenance, or repair, the opening of the housing 10 can be easily opened or closed by disassembling and reassembling the base 13, allowing operation of components such as the liquid level detection assembly 20 within the receiving cavity 11. For example, when it is necessary to replace the float 21, connecting rod 22, or liquid level monitoring module 23, the base 13 can be removed to expose the opening for related operations. After the operations are completed, the base 13 can be reinstalled in its original position to seal the opening, ensuring the sealing and normal operation of the device.

[0060] Furthermore, in this embodiment, both the inner wall of the outer shell 10 facing the receiving cavity 11 and the inner wall of the base 13 facing the receiving cavity 11 have shielding portions 12. That is, not only the inner wall of the outer shell 10 has shielding portions 12 for shielding nuclear radiation, but the inner wall of the base 13 facing the receiving cavity 11 is also provided with shielding portions 12. This can more comprehensively shield external nuclear radiation and prevent nuclear radiation from entering the receiving cavity 11 from the opening of the outer shell 10 and the connection between the base 13 and the outer shell 10, thus preventing it from affecting radiation-sensitive components such as the internal liquid level monitoring module 23. By providing shielding portions 12 on the inner walls of both the outer shell 10 and the base 13, a relatively closed space with good nuclear radiation shielding effect can be formed, ensuring that the liquid level detection device can work stably and accurately in the strong radiation environment of a nuclear power plant.

[0061] In a specific embodiment, such as Figure 2 As shown, the outer shell 10 is a stainless steel outer shell 10, the base 13 is a stainless steel base 13, and the shielding part 12 includes a shielding layer 121 attached to the inner side wall of the outer shell 10 and the inner side wall of the base 13.

[0062] That is, both the outer shell 10 and the base 13 are made of stainless steel. Stainless steel has high strength and hardness, and can withstand certain external forces and pressures, providing reliable support and protection for the liquid level detection device. The shielding part 12 is attached to the inner wall of the outer shell 10 and the base 13 in the form of a shielding layer 121. The shielding part 12 can better adapt to the shape of the outer shell 10 and the base 13. No matter how complex the shape, the shielding layer 121 can fit tightly, thereby providing comprehensive and uniform nuclear radiation shielding. The installation of the shielding layer 121 by attaching it to the base makes the setup of the shielding part 12 relatively simple and convenient. During the manufacturing process, the shielding layer 121 can be processed into a suitable size and shape first, and then directly pasted or fixed to the inner wall of the pre-processed outer shell 10 and the base 13. There is no need for complex overall casting or assembly processes, which helps to improve production efficiency and reduce manufacturing costs. Furthermore, if the shielding part 12 is damaged or aged during use and needs maintenance or replacement, only the damaged shielding layer 121 can be removed and replaced, without the need for large-scale disassembly and repair of the entire housing 10 or base 13. This reduces maintenance workload and downtime, and improves the maintainability of the liquid level detection device.

[0063] In other embodiments, unlike the embodiments described above, such as Figure 3 As shown, the shielding part 12 includes a base 13 and a shielding layer 121 attached to the inner sidewall of the outer casing 10. The outer casing 10 is a stainless steel outer casing 10.

[0064] That is, in this embodiment, the outer shell 10 is made of stainless steel, and the shielding part 12 includes two parts, one part is a shielding layer 121 attached to the inner side wall of the outer shell 10, and the other part is a base 13. That is, the base 13 is a structure made of a material with nuclear radiation shielding effect such as lead or concrete, and it is directly connected to the outer shell 10 as part of the shielding part 12.

[0065] In some embodiments, the lubricating oil level detection device for the bearing chamber of the nuclear main pump motor further includes a temperature detection component 30. The temperature detection component 30 includes a temperature sensor 31 and a temperature transmission module 32. The temperature sensor 31 is installed on the float 21 and can be placed in the lubricating oil together with the float 21 to detect the temperature of the lubricating oil. The temperature transmission module 32 is installed in the receiving cavity 11. The temperature sensor 31 and the temperature transmission module 32 are electrically connected. The temperature transmission module 32 is used to receive and transmit the temperature information detected by the temperature sensor 31 to the outside.

[0066] In this embodiment, as Figures 1 to 3 As shown, the level detection device also includes a temperature detection component 30. That is, in addition to detecting the lubricating oil level, the detection device in this embodiment also has the ability to detect the lubricating oil temperature. During the operation of the nuclear main pump motor, the temperature of the lubricating oil is a crucial parameter, affecting the lubrication effect and wear of the motor bearings, as well as the stability of the entire system. Therefore, adding a temperature detection function allows for more comprehensive monitoring of the lubricating oil's condition.

[0067] In a specific embodiment, the temperature detection component 30 includes a temperature sensor 31 and a temperature transmission module 32. The temperature sensor 31 is mounted on a float 21, ensuring the float 21 is always immersed in lubricating oil, allowing the temperature sensor 31 to accurately detect the lubricating oil temperature in real time. The temperature sensor 31 is in direct contact with the lubricating oil, enabling it to quickly respond to changes in lubricating oil temperature and ensuring the timeliness and accuracy of the detected temperature information. The temperature transmission module 32 is installed within the housing cavity 11 and electrically connected to the temperature sensor 31. The main function of the temperature transmission module 32 is to receive the temperature signals detected by the temperature sensor 31, process these signals, and transmit them externally so that operators or related systems can obtain the lubricating oil temperature information. The temperature transmission module 32 is installed within the housing cavity, allowing it to be surrounded by the shielding part 12, thereby effectively reducing the impact of nuclear radiation on the temperature transmission module 32 and improving the accuracy and reliability of temperature information transmission.

[0068] In this embodiment of the liquid level detection device, during use, the temperature sensor 31, along with the float 21, detects the temperature in the lubricating oil in real time, converting the temperature signal into a transmittable signal form such as an electrical signal. This signal is then transmitted via an electrical connection to the temperature transmission module 32 installed in the receiving cavity 11. The temperature transmission module 32 further processes the received signal, such as amplifying and converting it, before transmitting it externally, enabling external devices or systems to acquire and analyze the lubricating oil temperature data. For example, when the lubricant temperature is 40°C, the temperature sensor 31 detects the current temperature and transmits this information to the temperature transmission module 32, which outputs that the current lubricant temperature is 40°C. Similarly, when the lubricant temperature is 50°C or 80°C, the temperature sensor 31 can also acquire this temperature information in real time and output the current lubricant temperature as 50°C or 80°C through the temperature transmission module 32.

[0069] In a specific embodiment, the temperature sensor 31 can be a platinum resistance sensor. A platinum resistance sensor is a sensor element that measures temperature by utilizing the property that the resistance value of platinum metal changes with temperature. It has a large measurable temperature range, and within its operating temperature range, the linear relationship between the resistance value and temperature is good. This makes temperature measurement and calculation relatively simple, and facilitates linear fitting and data processing, so as to obtain the temperature of the lubricant more accurately.

[0070] Of course, in other embodiments, the temperature sensor 31 may also be a thermocouple sensor, etc.

[0071] In some embodiments, the float 21 has a heat-conducting part on at least the side away from the connecting rod 22, and the temperature sensor 31 is installed inside the float 21 and is thermally connected to the heat-conducting part. The temperature sensor 31 detects the temperature of the lubricating oil by detecting the temperature of the heat-conducting part.

[0072] The float 21 has a heat-conducting part on at least the side away from the connecting rod 22. The side of the float 21 away from the connecting rod 22 is in direct contact with the lubricating oil. The heat of the lubricating oil is transferred to the heat-conducting part. The temperature sensor 31 is installed inside the float 21. The temperature of the lubricating oil is indirectly measured by detecting the temperature of the heat-conducting part.

[0073] The heat-conducting part is a structural part made of copper or other good conductors of heat. The material of other positions on the float 21 can be the same as or different from the material of the heat-conducting part. For example, the float 21 can be a metal float 21, such as a copper ball, an aluminum ball, or a stainless steel ball.

[0074] Alternatively, in other embodiments, such as Figures 1 to 3 As shown, the float 21 has a through hole 211 on the side away from the connecting rod 22. The temperature sensor 31 includes a main body 311 and a temperature probe 312. The main body 311 is installed inside the float 21. The temperature probe 312 is sealed and inserted into the through hole 211. The end of the temperature probe 312 away from the main body 311 protrudes from the through hole 211 for insertion into the lubricating oil.

[0075] The temperature sensor 31 comprises a main body 311 and a temperature probe 312. The main body 311 is installed inside the float 21, which protects the main body 311 from corrosion by lubricating oil and external physical impacts, ensuring the stability and reliability of the temperature sensor 31. The temperature probe 312 is inserted into the through hole 211 of the float 21 and is sealed to prevent lubricating oil from entering the float 21 through the through hole 211, thus avoiding damage to other components inside the float 21. The end of the temperature probe 312 facing away from the main body 311 protrudes from the through hole 211 and is directly inserted into the lubricating oil. The temperature probe 312 is in full contact with the lubricating oil, enabling it to quickly and accurately sense temperature changes in the lubricating oil and transmit the temperature signal to the main body 311 for processing and conversion.

[0076] Another embodiment of this application also provides a nuclear main pump motor, which should be considered in conjunction with this embodiment. Figure 1 The nuclear main pump motor includes a motor host (not shown) and a liquid level detection device for the lubricating oil in the bearing chamber of the nuclear main pump motor provided in any of the above embodiments. The motor host has a bearing chamber containing lubricating oil. The liquid level detection device is detachably installed on the motor host. The housing 10 of the liquid level detection device is located outside the bearing chamber. Along the height direction of the lubricating oil, one end of the connecting rod 22 connected to the float 21 slides through the chamber wall of the bearing chamber and extends into the bearing chamber. The float 21 is immersed in the lubricating oil.

[0077] This approved pump motor achieves real-time detection of the lubricating oil level in its bearing chamber through a liquid level detection device. The float 21, via a connecting rod 22, penetrates the side wall of the bearing chamber and is directly immersed in the lubricating oil, making the liquid level detection more direct and accurate. Furthermore, in designs where the liquid level detection device also includes a temperature detection component 30, real-time detection of the lubricating oil temperature is also possible. In these designs, the temperature sensor 31 is housed within the float 21 and placed within the bearing chamber, where it is shielded from nuclear radiation, thus reducing the risk of interference from nuclear radiation to the temperature sensor 31 and improving the accuracy of temperature detection.

[0078] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0079] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A device for detecting the level of lubricating oil in the bearing chamber of a nuclear main pump motor, characterized in that, include: A housing for mounting the motor to the nuclear main pump, the housing being hollow and forming a receiving cavity; A liquid level detection assembly includes a float, a connecting rod, and a liquid level monitoring module. The liquid level monitoring module is installed inside the receiving cavity. One end of the connecting rod is located inside the receiving cavity and connected to the trigger element of the liquid level monitoring module. The other end of the connecting rod extends out from the housing and is connected to the float. The float is used to be placed in the lubricating oil in the bearing cavity of the motor. The liquid level monitoring module is used to detect the liquid level height of the lubricating oil based on the floating of the float and transmit the detected liquid level height information to the outside. The outer shell further includes a shielding portion, which is at least located on the inner wall of the outer shell facing the receiving cavity, and the shielding portion surrounds the receiving cavity to shield against external nuclear radiation.

2. The liquid level detection device for the lubricating oil in the bearing chamber of the nuclear main pump motor as described in claim 1, characterized in that, The shielding part is made of lead material or concrete material.

3. The liquid level detection device for the bearing chamber lubricating oil of the nuclear main pump motor as described in claim 1, characterized in that, The thickness of the shielding portion is 0.5cm to 5cm from the inside out of the receiving cavity.

4. The liquid level detection device for the lubricating oil in the bearing chamber of the nuclear main pump motor as described in claim 1, characterized in that, Along the axial direction of the connecting rod, the outer shell has an opening at one end facing the float. The outer shell is detachably connected to a base, which is adapted to cover the opening of the outer shell. The connecting rod passes through the base. The inner wall of the outer shell facing the receiving cavity and the inner wall of the base facing the receiving cavity both have the shielding part.

5. The lubricating oil level detection device for the bearing chamber of the nuclear main pump motor as described in claim 4, characterized in that, The outer shell is a stainless steel shell, the base is a stainless steel base, and the shielding part includes a shielding layer attached to the inner sidewall of the outer shell and the inner sidewall of the base.

6. The liquid level detection device for the lubricating oil in the bearing chamber of the nuclear main pump motor as described in any one of claims 1 to 5, characterized in that, The lubricating oil level detection device for the bearing chamber of the nuclear main pump motor further includes a temperature detection component. The temperature detection component includes a temperature sensor and a temperature transmission module. The temperature sensor is installed on the float and can be placed in the lubricating oil together with the float to detect the temperature of the lubricating oil. The temperature transmission module is installed in the receiving cavity. The temperature sensor is electrically connected to the temperature transmission module. The temperature transmission module is used to receive and transmit the temperature information detected by the temperature sensor to the outside.

7. The liquid level detection device for the lubricating oil in the bearing chamber of the nuclear main pump motor as described in claim 6, characterized in that, The float has a through hole on the side away from the connecting rod. The temperature sensor includes a main body and a temperature probe. The main body is installed inside the float. The temperature probe is sealed and inserted into the through hole. The end of the temperature probe away from the main body protrudes from the through hole for insertion into the lubricating oil. Alternatively, the float may have a heat-conducting part on at least the side opposite to the connecting rod, and the temperature sensor may be installed inside the float and thermally connected to the heat-conducting part. The temperature sensor may detect the temperature of the lubricating oil by detecting the temperature of the heat-conducting part.

8. The lubricating oil level detection device for the bearing chamber of the nuclear main pump motor as described in claim 7, characterized in that, The float is a metal ball.

9. The liquid level detection device for the lubricating oil in the bearing chamber of the nuclear main pump motor as described in claim 7, characterized in that, The temperature sensor is a platinum resistance temperature sensor.

10. A nuclear main pump motor, characterized in that, The device includes a motor and a level detection device for lubricating oil in the bearing chamber of a nuclear main pump motor as described in any one of claims 1 to 9, wherein the motor has a bearing chamber containing lubricating oil, and the level detection device is detachably installed on the motor. The housing of the liquid level detection device is located outside the bearing chamber. Along the height direction of the lubricating oil, one end of the connecting rod connected to the float slides through the chamber wall of the bearing chamber and extends into the bearing chamber, and the float is immersed in the lubricating oil.

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