A compressed cycle molten salt circulating pump

Abstract

The present application relates to molten salt circulating pump technical field, especially to a kind of compressed circulating molten salt circulating pump, comprising: transmission mechanism, to transport circulating material;Sealing mechanism;Detection mechanism, including parallel to the outer facade of pump body to obtain the temperature of several temperature detection regions in infrared image by collecting the infrared image of pump body infrared imager and with the pressure measurement component of pump body to detect the pressure of sealing end face;Control mechanism, to determine the symmetry state of pump body according to the standard deviation difference value of the horizontal distance of the corresponding temperature detection region of the region on both sides of the axis of pump body and the reference vertical section corresponding to the axis of pump body, determine the axial micro-displacement of impeller according to the pressure of sealing end face, determine the centrifugal force of impeller according to the number of temperature detection region.The present application realizes the improvement of the running stability of molten salt circulating pump.

Description

Technical Field

[0001] This invention relates to the field of molten salt circulating pump technology, and more particularly to a compression-circulation molten salt circulating pump. Background Technology

[0002] In existing technologies, molten salt circulation pumps are key equipment used in high-temperature and high-pressure environments, especially in fields such as concentrated solar power generation, nuclear energy systems, and industrial waste heat recovery. The main task of these pumps is to transport high-temperature molten salt from cold tanks to heat exchangers or reactors, where it is heated and then transported to hot tanks or used for further processing. Currently, centrifugal pumps are the mainstream choice due to their large flow rate, high efficiency, and stable operation, making them suitable for continuous circulation. Axial flow pumps or multi-stage centrifugal pumps are also used in some low-flow, high-head applications. Positive displacement pumps, such as gear pumps and plunger pumps, are less commonly used in main circulation systems because sealing is difficult and they are prone to wear. Since the temperature of molten salt can reach over 500℃, traditional mechanical seals are insufficient, and magnetic drive seals or high-temperature mechanical seals are often used in conjunction with cooling systems.

[0003] Chinese Patent Publication No. CN117190767A discloses a molten salt thermal storage system with adjustable thermocline thickness and its operation method, including a thermocline molten salt thermal storage tank, an upper salt distributor, a lower salt distributor, a tank internal temperature detection device, a high-temperature molten salt outlet temperature detector, a low-temperature molten salt outlet temperature detector, a low-temperature molten salt inlet temperature detector, a high-temperature molten salt inlet temperature detector, a low-temperature molten salt inlet valve, a high-temperature molten salt outlet valve, a low-temperature molten salt outlet valve, a high-temperature molten salt inlet valve, a high-temperature molten salt temperature regulating valve, a high-temperature molten salt circulation pump, a low-temperature molten salt circulation pump, an ultrasonic flow meter, a cold source device, an external cold medium inlet, an external cold medium outlet, a heat source device, an external heat medium inlet, an external heat medium outlet, and... The controller; the inclined temperature layer molten salt storage tank is equipped with an upper salt distributor and a lower salt distributor in the upper and lower parts respectively; the inlet of the upper salt distributor and the high-temperature molten salt circulation pump are connected through a high-temperature molten salt outlet valve; a high-temperature molten salt outlet temperature detector is arranged on the high-temperature molten salt outlet pipe between the high-temperature molten salt outlet valve and the upper salt distributor; the outlet of the high-temperature molten salt circulation pump is connected to the inlet of the ultrasonic flow meter through a pipe; the outlet of the ultrasonic flow meter is connected to the high-temperature molten salt inlet of the cold source device through a pipe; the low-temperature molten salt outlet of the cold source device is connected to the lower salt distributor through a low-temperature molten salt inlet valve; a low-temperature molten salt inlet temperature detector is set at the low-temperature molten salt outlet of the cold source device; the cold source device is equipped with an external cold medium inlet and an external cold medium outlet. The inlet of the lower salt distributor and the inlet of the cryogenic molten salt circulating pump are connected through a cryogenic molten salt outlet valve; a cryogenic molten salt outlet temperature detector is installed on the cryogenic molten salt outlet pipe between the cryogenic molten salt outlet valve and the lower salt distributor; the outlet of the cryogenic molten salt circulating pump is connected to the inlet of the ultrasonic flow meter through a pipe; the outlet of the ultrasonic flow meter is connected to the cryogenic molten salt inlet of the heat source device through a pipe; the high-temperature molten salt outlet of the heat source device is connected to the upper salt distributor through a high-temperature molten salt inlet valve; a high-temperature molten salt temperature regulating branch is set between the outlet of the cryogenic molten salt circulating pump and the inlet of the ultrasonic flow meter, and a high-temperature molten salt temperature regulating valve is installed on the high-temperature molten salt temperature regulating branch; a high-temperature molten salt inlet temperature detector is installed at the high-temperature molten salt outlet valve. Between the regulating valve and the high-temperature molten salt inlet valve; the heat source device is equipped with an external heat medium inlet and an external heat medium outlet; the tank temperature detection device, the low-temperature molten salt inlet valve, the high-temperature molten salt inlet valve, the low-temperature molten salt outlet valve, the high-temperature molten salt inlet valve, the high-temperature molten salt temperature regulating valve, the high-temperature molten salt circulation pump, and the low-temperature molten salt circulation pump are all connected to the controller. The controller determines the thickness of the inclined temperature layer in the inclined temperature layer molten salt heat storage tank based on the water temperature distribution obtained by the tank temperature detection device, and controls the opening and closing of the low-temperature molten salt inlet valve, the high-temperature molten salt outlet valve, the low-temperature molten salt outlet valve, the high-temperature molten salt inlet valve, the high-temperature molten salt temperature regulating valve, the high-temperature molten salt circulation pump, and the low-temperature molten salt circulation pump based on the thickness of the inclined temperature layer.It can be seen that the molten salt thermal storage system and its operation method with adjustable slope layer thickness have the problem of excessively high local temperature at the molten salt accumulation site due to the difference in surface roughness at various locations in the pump body during the transportation of molten salt. The accumulation at the sealing port leads to poor expansion uniformity in the pump body, which in turn causes shaft yaw vibration. Summary of the Invention

[0004] To address this issue, the present invention provides a molten salt circulation pump with compression circulation, which overcomes the problem in the prior art where, during the transportation of molten salt, the local temperature at the accumulation site of molten salt particles is too high due to the difference in surface roughness at various locations within the pump body, and the accumulation at the sealing port leads to poor expansion uniformity within the pump body, resulting in shaft wobbling vibration.

[0005] To achieve the above objectives, the present invention provides a molten salt circulation pump for compression circulation, comprising:

[0006] A transmission mechanism for conveying circulating materials includes a pump body, an impeller disposed inside the pump body for generating centrifugal force, and a motor connected to the impeller for adjusting the impeller speed.

[0007] A sealing mechanism, which is connected to the transmission mechanism, is used to isolate air outside the pump body, including a rotating ring connected to the pump body and a stationary ring disposed outside the rotating ring;

[0008] The detection mechanism, which is connected to the transmission mechanism and the sealing mechanism respectively, includes an infrared imager parallel to the outer surface of the pump body for acquiring the temperature of several temperature detection areas in the infrared image by acquiring the infrared image of the pump body, and a pressure measuring component connected to the pump body for detecting the pressure of the sealing end face between the dynamic ring and the stationary ring.

[0009] A control mechanism, connected to the transmission mechanism, the sealing mechanism, and the detection mechanism, is used to determine the symmetry state of the pump body based on the standard deviation of the horizontal distance between the corresponding temperature detection areas on both sides of the pump body axis and the reference vertical section corresponding to the pump body axis; to determine the axial micro-displacement of the impeller based on the pressure of the sealing end face and the corresponding symmetry state; and to determine the centrifugal force of the impeller based on the number of temperature detection areas and the pressure of the sealing end face, wherein the centrifugal force is positively correlated with the number of temperature detection areas.

[0010] Furthermore, the pump body includes an inlet assembly for conveying circulating material and an outlet assembly for discharging the circulating material.

[0011] The feed inlet assembly includes a first grease inlet, a second grease inlet, a cooling water inlet, a molten salt inlet, a first steam inlet, a second steam inlet, a third steam inlet, a fourth steam inlet, and a blower.

[0012] The discharge port assembly includes a cooling water discharge port, a molten salt discharge port, an overflow port, a drain port, a first steam condensate discharge port, a second steam condensate discharge port, a third steam condensate discharge port, and a fourth steam condensate discharge port.

[0013] Furthermore, the pressure measuring assembly includes several pressure sensors connected to the sealing end face for detecting the pressure between the moving ring and the stationary ring.

[0014] Furthermore, if the standard deviation difference between the regions on both sides of the axis is greater than or equal to the preset difference, then the symmetry state of the pump body is determined to be asymmetrical distribution.

[0015] If the standard deviation difference between the regions on both sides of the axis is less than the preset difference, then the symmetry state of the pump body is determined to be symmetrical distribution.

[0016] Furthermore, the temperature detection area on the left side of the vertical cross-section of the pump body where the temperature is greater than or equal to the average temperature is designated as the first high-temperature detection area, and the center point of the first high-temperature detection area is designated as the first high-temperature point; the temperature detection area on the right side of the vertical cross-section of the pump body where the temperature is greater than or equal to the average temperature is designated as the second high-temperature detection area, and the center point of the second high-temperature detection area is designated as the second high-temperature point;

[0017] The standard deviations of the horizontal distances corresponding to the regions on both sides of the axis are calculated based on the horizontal distances between several first high-temperature points and the reference plane of the pump body axis, and the horizontal distances between several second high-temperature points and the reference plane of the pump body axis.

[0018] The standard deviation is calculated based on the standard deviation of the horizontal distance corresponding to the regions on both sides of the axis.

[0019] Furthermore, the standard deviation difference is the absolute value of the difference between the horizontal distance standard deviation corresponding to the first high temperature point and the horizontal distance standard deviation corresponding to the second high temperature point.

[0020] Furthermore, the control mechanism is connected to several pressure sensors and the sealing mechanism respectively, to obtain the set sealing pressure of the sealing mechanism and the pressure of the sealing end face, calculate the average sealing pressure based on the pressure of the sealing end face, and calculate the sealing pressure difference based on the set sealing pressure and the average sealing pressure.

[0021] If the sealing pressure difference is greater than or equal to the preset pressure difference, and the symmetry state is asymmetrically distributed, then the number of the first high temperature points and the number of the second high temperature points are compared, and the centrifugal force on the impeller side with more high temperature points is increased, while the centrifugal force on the impeller side with fewer high temperature points is decreased.

[0022] Furthermore, if the sealing pressure difference is greater than or equal to the preset pressure difference and the symmetry is symmetrically distributed, then the axial micro-displacement of the impeller toward the sealing mechanism side is increased.

[0023] Furthermore, the sealing pressure difference is equal to the difference between the set sealing pressure and the average sealing pressure.

[0024] Furthermore, the average sealing pressure is the ratio of the sum of pressures detected by a plurality of pressure sensors to the number of pressure sensors.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: The device of the present invention, by setting up a transmission mechanism, a sealing mechanism, a detection mechanism, and a control mechanism, addresses the issue that the molten salt accumulates and cools in a pit with a larger heat dissipation area due to the surface roughness differences at various locations on the inner surface of the pump body. Molten salt is a high-temperature corrosive material, and the accumulated molten salt exacerbates the thermal deformation of the pump body, causing local overheating and resulting in asymmetrical thermal deformation and mechanical vibration. By adjusting the centrifugal force distribution of the impeller, the impeller load is balanced. The adjusted centrifugal force distribution allows the flowing molten salt to pass through areas of high centrifugal force, pushing the molten salt to scour the deposition area at high speed, destroying the accumulation structure, while avoiding excessive disturbance on the low-temperature side. If the molten salt accumulation occurs in the sealing mechanism, it will cause changes in the pressure difference between the inside and outside of the sealing mechanism. The sealing mechanism near the molten salt accumulation location will experience sealing fatigue wear due to local overheating. By adjusting the axial micro-displacement, the thermal expansion effect is used to change the sealing surface pressure, thereby effectively compensating for the sealing surface deformation caused by local temperature differences and improving the adaptability and stability of the sealing mechanism.

[0026] Furthermore, the device of the present invention, by setting up several inlet groups and several outlet groups, enables the circulating material to be evenly distributed when entering the pump body, reduces the local temperature gradient and pressure fluctuation caused by uneven material flow, improves the flow field stability during molten salt transportation, reduces vibration and noise caused by material impact or backflow, and further improves the operational stability of the molten salt circulating pump.

[0027] Furthermore, the device of the present invention uses an infrared imager to monitor the temperature of key areas on the outer surface of the pump body in real time to determine whether there is a risk of abnormal temperature rise or local overheating; the pressure sensor continuously monitors the pressure distribution between the sealing mechanism and the sealing end face of the pump body to ensure that the sealing surface always maintains a uniform stress state and prevents unplanned shutdowns caused by seal failure or thermal deformation.

[0028] Furthermore, the device of the present invention calculates the sealing pressure difference. When it is determined to be symmetrically distributed and there is a large sealing pressure difference, the control mechanism adjusts the axial micro-displacement of the impeller to compensate for the deformation deviation of the sealing surface caused by the difference in thermal expansion, so that the sealing surface is restored to a good fit and the risk of leakage is avoided. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the molten salt circulation pump for compression circulation according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram showing the orientation of the inlet of the molten salt circulation pump in the compression cycle according to an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the inlet orientation of the molten salt circulation pump in the compression cycle according to an embodiment of the present invention;

[0032] The reference numerals are as follows: a-first grease inlet, b-second grease inlet, C1-cooling water inlet, C2-cooling water outlet, N1-molten salt outlet, N2-molten salt inlet, N3-overflow outlet, N4-drain outlet, N5-first steam inlet, N6-first steam condensate outlet, N7-second steam inlet, N8-second steam condensate outlet, N91-third steam inlet, N92-fourth steam inlet, N101-third steam condensate outlet, N102-fourth steam condensate outlet, N11-air vent, A-pump body. Detailed Implementation

[0033] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0034] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0035] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0036] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] Please see Figure 1 , Figure 2 , Figure 3 The figures shown are a schematic diagram of the overall structure, a schematic diagram of the pipe orientation, and a schematic diagram from another angle of the molten salt circulating pump for compression circulation according to an embodiment of the present invention. The present invention provides a molten salt circulating pump for compression circulation, comprising:

[0038] A transmission mechanism for conveying circulating materials includes a pump body A, an impeller disposed inside the pump body for generating centrifugal force, and a motor connected to the impeller for adjusting the impeller speed.

[0039] A sealing mechanism, which is connected to the transmission mechanism, is used to isolate air outside the pump body, including a rotating ring connected to the pump body and a stationary ring disposed outside the rotating ring;

[0040] The detection mechanism, which is connected to the transmission mechanism and the sealing mechanism respectively, includes an infrared imager parallel to the outer surface of the pump body for acquiring the temperature of several temperature detection areas in the infrared image by acquiring the infrared image of the pump body, and a pressure measuring component connected to the pump body for detecting the pressure of the sealing end face between the dynamic ring and the stationary ring.

[0041] A control mechanism, connected to the transmission mechanism, the sealing mechanism, and the detection mechanism, is used to determine the symmetry state of the pump body based on the standard deviation of the horizontal distance between the corresponding temperature detection areas on both sides of the pump body axis and the reference vertical section corresponding to the pump body axis; to determine the axial micro-displacement of the impeller based on the pressure of the sealing end face and the corresponding symmetry state; and to determine the centrifugal force of the impeller based on the number of temperature detection areas and the pressure of the sealing end face, wherein the centrifugal force is positively correlated with the number of temperature detection areas.

[0042] Specifically, the horizontal cross-sections of the cylindrical parts along the vertical direction in pump body A are circular and concentric.

[0043] The axis is the vertical line containing the center of the horizontal cross-section of each cylindrical part;

[0044] The reference vertical section corresponding to the axis of the pump body is a reference plane that includes the axis of the pump body and is perpendicular to the end face of the molten salt outlet.

[0045] In implementation, the device of this invention, by setting up a transmission mechanism, a sealing mechanism, a detection mechanism, and a control mechanism, addresses the issue of molten salt accumulating and cooling in a larger heat dissipation pit due to surface roughness differences at various locations on the inner surface of the pump body. Molten salt is a high-temperature corrosive material, and the accumulated molten salt exacerbates the thermal deformation of the pump body, causing local overheating and resulting in asymmetrical thermal deformation and mechanical vibration. By adjusting the centrifugal force distribution of the impeller, the impeller load is balanced. The adjusted centrifugal force distribution allows the flowing molten salt to pass through areas of high centrifugal force, pushing the molten salt to scour the deposition area at high speed, thus destroying the accumulation structure, while avoiding excessive disturbance on the low-temperature side. If the molten salt accumulation occurs in the sealing mechanism, it will cause changes in the pressure difference between the inside and outside of the sealing mechanism. The sealing mechanism near the molten salt accumulation location will experience sealing fatigue wear due to local overheating. By adjusting the axial micro-displacement, the thermal expansion effect is used to change the sealing surface pressure, thereby effectively compensating for the sealing surface deformation caused by local temperature differences and improving the adaptability and stability of the sealing mechanism.

[0046] Specifically, the pump body includes an inlet assembly for conveying circulating material and an outlet assembly for discharging the circulating material.

[0047] The feed inlet assembly includes a first grease inlet a, a second grease inlet b, a cooling water inlet C1, a molten salt inlet N2, a first steam inlet N5, a second steam inlet N7, a third steam inlet N91, a fourth steam inlet N92, and a blower N11.

[0048] The discharge port assembly includes a cooling water discharge port C2, a molten salt discharge port N1, an overflow port N3, a drain port N4, a first steam condensate discharge port N6, a second steam condensate discharge port N8, a third steam condensate discharge port N101, and a fourth steam condensate discharge port N102.

[0049] In practice, the device of the present invention, by setting up several inlet groups and several outlet groups, enables the circulating material to be evenly distributed when entering the pump body, reduces the local temperature gradient and pressure fluctuation caused by uneven material flow, improves the flow field stability during molten salt conveying, reduces vibration and noise caused by material impact or backflow, and further improves the operational stability of the molten salt conveying mechanism.

[0050] Specifically, the pressure measuring assembly includes several pressure sensors connected to the sealing end face for detecting the pressure between the moving ring and the stationary ring.

[0051] Specifically, the pressure sensors are circumferentially positioned at the sealing section between the moving ring and the stationary ring, with one pressure sensor installed at 90° intervals, for a total of four sensors.

[0052] In practice, the device of the present invention uses an infrared imager to monitor the temperature of key areas on the outer surface of the pump body in real time to determine whether there is a risk of abnormal temperature rise or local overheating; the pressure sensor continuously monitors the pressure distribution of the sealing mechanism and the sealing end face of the pump body to ensure that the sealing surface always maintains a uniform stress state and prevents unplanned shutdowns caused by sealing failure or thermal deformation.

[0053] Specifically, the temperature detection area on the left side of the vertical cross-section of the pump body reference that satisfies the condition of a temperature greater than or equal to the average temperature is designated as the first high-temperature detection area, and the center point of the first high-temperature detection area is designated as the first high-temperature point; the temperature detection area on the right side of the vertical cross-section of the pump body reference that satisfies the condition of a temperature greater than or equal to the average temperature is designated as the second high-temperature detection area, and the center point of the second high-temperature detection area is designated as the second high-temperature point;

[0054] The standard deviations of the horizontal distances corresponding to the regions on both sides of the axis are calculated based on the horizontal distances between several first high-temperature points and the reference plane of the pump body axis, and the horizontal distances between several second high-temperature points and the reference plane of the pump body axis.

[0055] The standard deviation is calculated based on the standard deviation of the horizontal distance corresponding to the regions on both sides of the axis.

[0056] Specifically, the average temperature is the ratio of the sum of the temperature values ​​corresponding to all valid pixels in the infrared image to the number of valid pixels, where valid pixels are pixels that can output true infrared radiation signals.

[0057] Specifically, the center point is the geometric center of the physical shape of the first / second high-temperature detection area.

[0058] Specifically, the standard deviation difference is the absolute value of the difference between the horizontal distance standard deviation corresponding to the first high temperature point and the horizontal distance standard deviation corresponding to the second high temperature point.

[0059] Specifically, if the standard deviation difference between the regions on both sides of the axis is greater than or equal to the preset difference, then the symmetry state of the pump body is determined to be asymmetrical distribution.

[0060] If the standard deviation difference between the regions on both sides of the axis is less than the preset difference, then the symmetry state of the pump body is determined to be symmetrical distribution.

[0061] Specifically, with a pump body length of 1.2m and an impeller diameter of 40cm, the general range of the preset difference is [0.5mm, 2.0mm], and the preferred embodiment of the preset difference is 1.5mm.

[0062] Those skilled in the art will understand that the range of preset differences and preferred embodiments provided in this embodiment are the values ​​that best address the technical problem solved by the present invention under the conditions of a pump body length of 1.2m and an impeller diameter of 40cm. In actual applications or experiments, those skilled in the art can make adaptive adjustments to the preset differences according to the actual application environment and application scenario.

[0063] Specifically, the control mechanism is connected to several pressure sensors and the sealing mechanism to acquire the set sealing pressure of the sealing mechanism and the pressure of the sealing end face, calculate the average sealing pressure based on the pressure of the sealing end face, and calculate the sealing pressure difference based on the set sealing pressure and the average sealing pressure.

[0064] If the sealing pressure difference is greater than or equal to the preset pressure difference, and the symmetry state is asymmetrically distributed, then the number of the first high temperature points and the number of the second high temperature points are compared, and the centrifugal force on the impeller side with more high temperature points is increased, while the centrifugal force on the impeller side with fewer high temperature points is decreased.

[0065] Specifically, embodiments of methods for increasing / decreasing centrifugal force include adjusting the lead angle of the impeller unit blade and adjusting the rotational angular velocity. In this embodiment of the invention, the centrifugal force is increased by reducing the rotational angular velocity of the blades on the side of the impeller with more high-temperature points.

[0066] Specifically, under the conditions of a pump body length of 1.2m, an impeller diameter of 40cm, a dynamic ring inner diameter of 50mm, a stationary ring inner diameter of 52~55mm, and a design working pressure of 1.6MPa for the sealing end face, the general range of the preset pressure difference is [0.1MPa, 0.5MPa], and the preferred embodiment of the preset pressure difference is 0.3MPa.

[0067] Those skilled in the art will understand that the range of preset pressure difference and the preferred embodiment provided in this embodiment are the values ​​that best address the technical problem solved by the present invention, under the conditions that the pump body length is 1.2m, the impeller diameter is 40cm, the inner diameter of the moving ring is 50mm, the inner diameter of the stationary ring is 52~55mm, and the design working pressure of the sealing end face is 1.6MPa. In actual applications or experiments, those skilled in the art can make adaptive adjustments to the preset pressure difference according to the actual application environment and application scenario.

[0068] In implementation, if the difference between the sealing pressure difference and the preset pressure difference is within 0.01 MPa, and the difference in the number of high-temperature points on both sides of the axis is within 2, then the rotational angular velocity of the blades on the impeller side with more high-temperature points is increased by 0.5 rad / s, while the rotational angular velocity of the blades on the impeller side with fewer high-temperature points is decreased by 0.5 rad / s. If the difference between the sealing pressure difference and the preset pressure difference exceeds 0.01 MPa, and the difference in the number of high-temperature points on both sides of the axis exceeds 2, then the rotational angular velocity of the blades on the impeller side with more high-temperature points is increased by [a certain percentage]. The corresponding relationship is: Increased rotational angular velocity = 0.8 rad·s⁻¹ / (MPa·number of points) × difference between sealing pressure difference and preset pressure difference × difference in the number of high-temperature points on both sides of the axis. For example, if the difference between sealing pressure difference and preset pressure difference is 0.2 MPa, and the difference in the number of high-temperature points on both sides of the axis is 5, then the rotational angular velocity of the blades on the impeller side with more high-temperature points increases by 0.8 × 0.2 × 5 = 0.8 rad / s, and the rotational angular velocity of the blades on the impeller side with fewer high-temperature points decreases by 0.8 rad / s; where 0.8 rad·s -1 When the sealing pressure difference exceeds the threshold of 1 MPa and the difference in the number of high-temperature points is 1, the angular velocity needs to be adjusted to 0.8 rad / s. This is based on the experimental proportionality coefficient obtained through experiments under the conditions of impeller diameter of 0.4 m and molten salt density of 1800 kg / m³.

[0069] Specifically, the increase / decrease in rotational angular velocity cannot exceed 2 rad / s.

[0070] Specifically, if the sealing pressure difference is greater than or equal to the preset pressure difference and the symmetry is symmetrically distributed, then the axial micro-displacement of the impeller toward the sealing mechanism side is increased.

[0071] Specifically, the sealing pressure difference is equal to the difference between the set sealing pressure and the average sealing pressure.

[0072] Specifically, the average sealing pressure is the ratio of the sum of pressures detected by a number of pressure sensors to the number of pressure sensors.

[0073] Specifically, the sealing pressure is set to the working pressure value set by the sealing mechanism before the lava circulation pump of this embodiment of the invention starts working.

[0074] Specifically, the axial micro-displacement is positively correlated with the sealing pressure difference.

[0075] Specifically, axial micro-displacement is achieved through a hydraulic actuator or a magnetic levitation drive, with a maximum allowable adjustment of 0.5 mm.

[0076] Specifically, the axial micro-displacement can be achieved through a hydraulic actuator, a magnetic levitation drive, or motor harmonic adjustment, with an adjustment accuracy of ±0.01mm and a maximum allowable adjustment range of ±0.5mm.

[0077] In practice, if the difference between the sealing pressure difference and the preset pressure difference is within 0.01 MPa, the axial micro-displacement increases by 0.02 mm. If the difference between the sealing pressure difference and the preset pressure difference exceeds 0.01 MPa, the axial micro-displacement increases by 0.01 mm for every 0.01 MPa increase. For example, if the difference between the sealing pressure difference and the preset pressure difference is 0.03 MPa, the axial micro-displacement increases by 0.02 mm + 0.01 mm + 0.01 mm = 0.04 mm.

[0078] In practice, the device of the present invention calculates the sealing pressure difference. When it is determined to be symmetrically distributed and there is a large sealing pressure difference, the control mechanism adjusts the axial micro-displacement of the impeller to compensate for the deformation deviation of the sealing surface caused by the difference in thermal expansion, so that the sealing surface is restored to a good fit and the risk of leakage is avoided.

[0079] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A molten salt circulating pump for compression circulation, characterized in that, include: A transmission mechanism for conveying circulating materials includes a pump body, an impeller disposed inside the pump body for generating centrifugal force, and a motor connected to the impeller for adjusting the impeller speed. A sealing mechanism, which is connected to the transmission mechanism, is used to isolate air outside the pump body, including a rotating ring connected to the pump body and a stationary ring disposed outside the rotating ring; The detection mechanism, which is connected to the transmission mechanism and the sealing mechanism respectively, includes an infrared imager parallel to the outer surface of the pump body for acquiring the temperature of several temperature detection areas in the infrared image by acquiring the infrared image of the pump body, and a pressure measuring component connected to the pump body for detecting the pressure of the sealing end face between the dynamic ring and the stationary ring. A control mechanism, which is connected to the transmission mechanism, the sealing mechanism, and the detection mechanism respectively, is used to determine the symmetry state of the pump body based on the standard deviation of the horizontal distance between the corresponding temperature detection areas on both sides of the pump body axis and the reference vertical section corresponding to the pump body axis; to determine the axial micro-displacement of the impeller based on the pressure of the sealing end face and the corresponding symmetry state; and to determine the centrifugal force of the impeller based on the number of temperature detection areas and the pressure of the sealing end face, wherein the centrifugal force is positively correlated with the number of temperature detection areas. The pump body includes an inlet assembly for conveying circulating material and an outlet assembly for discharging the circulating material. The feed inlet assembly includes a first grease inlet, a second grease inlet, a cooling water inlet, a molten salt inlet, a first steam inlet, a second steam inlet, a third steam inlet, a fourth steam inlet, and a blower. The discharge port assembly includes a cooling water discharge port, a molten salt discharge port, an overflow port, a drain port, a first steam condensate discharge port, a second steam condensate discharge port, a third steam condensate discharge port, and a fourth steam condensate discharge port; The pressure measuring assembly includes several pressure sensors connected to the sealing end face for detecting the pressure between the moving ring and the stationary ring; If the standard deviation difference between the regions on both sides of the axis is greater than or equal to the preset difference, then the symmetry state of the pump body is determined to be asymmetrical distribution. If the standard deviation difference between the regions on both sides of the axis is less than the preset difference, then the symmetry state of the pump body is determined to be symmetrical distribution; The temperature detection area on the left side of the vertical cross-section of the pump body where the temperature is greater than or equal to the average temperature is designated as the first high-temperature detection area, and the center point of the first high-temperature detection area is designated as the first high-temperature point; the temperature detection area on the right side of the vertical cross-section of the pump body where the temperature is greater than or equal to the average temperature is designated as the second high-temperature detection area, and the center point of the second high-temperature detection area is designated as the second high-temperature point. The standard deviations of the horizontal distances corresponding to the regions on both sides of the axis are calculated based on the horizontal distances between several first high-temperature points and the reference plane of the pump body axis, and the horizontal distances between several second high-temperature points and the reference plane of the pump body axis. Calculate the standard deviation value based on the standard deviation of the horizontal distance corresponding to the regions on both sides of the axis; The standard deviation difference is the absolute value of the difference between the horizontal distance standard deviation corresponding to the first high temperature point and the horizontal distance standard deviation corresponding to the second high temperature point; The control mechanism is connected to several pressure sensors and the sealing mechanism respectively, for acquiring the set sealing pressure of the sealing mechanism and the pressure of the sealing end face, calculating the average sealing pressure based on the pressure of the sealing end face, and calculating the sealing pressure difference based on the set sealing pressure and the average sealing pressure. If the sealing pressure difference is greater than or equal to the preset pressure difference, and the symmetry state is asymmetrically distributed, then the number of the first high temperature points and the number of the second high temperature points are compared, and the centrifugal force on the impeller side with more high temperature points is increased, while the centrifugal force on the impeller side with fewer high temperature points is decreased. If the sealing pressure difference is greater than or equal to the preset pressure difference and the symmetry is symmetrically distributed, then the axial micro-displacement of the impeller toward the sealing mechanism side is increased.

2. The molten salt circulating pump for compression circulation according to claim 1, characterized in that, The sealing pressure difference is equal to the difference between the set sealing pressure and the average sealing pressure.

3. The molten salt circulating pump for compression circulation according to claim 2, characterized in that, The average sealing pressure is the ratio of the sum of pressures detected by several pressure sensors to the number of pressure sensors.

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