Coaxial high-temperature pump
Through coaxial design and integrated heat dissipation device, the problems of leakage, cooling dependence and insufficient thermal management of high-temperature pumps are solved, efficient heat dissipation and equipment stability are achieved, and service life is extended and vibration is reduced.
Patent Information
- Application Number
- CN202510656346.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-21
- Publication Date
- 2025-07-18
AI Technical Summary
Existing high-temperature pumps have problems such as mechanical seal leakage, strong cooling dependence, insufficient thermal management and insufficient material high temperature resistance, resulting in short service life and unstable operation.
The coaxial design is adopted, and the pump body and the motor share the same axis, cancel the mechanical seal, and design the axial spiral flow path and the maze flow path for heat dissipation. Combined with the use of high and low thermal conductivity materials, the thermal expansion direction is controlled to compensate for axial deformation, and cooled by built-in coolant.
It effectively solves the leakage problem, improves heat dissipation efficiency and equipment stability, extends service life, reduces vibration and thermal stress, and ensures stable transportation of high-temperature working fluid.
Smart Images
Figure CN120332201A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a coaxial high-temperature pump, belonging to the technical field of liquid pumps. Background Art
[0002] The development of industry always progresses from large quantity and wide range to gradually improving performance parameters and process efficiency; the requirements of the process environment for pumps are also shifting towards high temperature and high pressure. High-temperature pumps are widely used in industrial fields such as petroleum, chemical industry, and pharmaceuticals that require a leak-free environment for transporting high-temperature working fluids. Currently, high-temperature pumps usually use an electric motor for driving. One end of the pump shaft is connected to the motor shaft, and the other end is connected to the impeller. Since both the pump shaft and the impeller are moving parts, the pump shaft needs to be connected to the pump housing through a mechanical seal, but the mechanical seal may have leakage, resulting in the leakage of high-temperature working fluids.
[0003] In addition, the existing high-temperature pumps also have the following problems:
[0004] 1. Strong cooling dependence: Traditional high-temperature pumps rely completely on an external cooling water system (such as cooling water spraying or an external cooler). In the standby state or when the cooling is interrupted, the temperature of the mechanical seal cavity rises rapidly, leading to rapid aging of the seal, thermal deformation of metal materials, and short service life.
[0005] 2. Insufficient thermal management: The high-temperature working fluid conducts through the pump body to the motor or bearing parts, causing thermal expansion, vibration, and material fatigue. For example, the magnetic steel rotor is offset due to high temperature, resulting in transmission failure.
[0006] 3. Material contradiction: The rotor of the high-temperature pump directly contacts the high-temperature working fluid. In the wet stator design, the stator directly contacts the high-temperature working fluid. Traditional sealing materials (such as graphite packing) have insufficient high-temperature resistance, and the heat dissipation path is single, easily leading to damage to the insulation layer and a decrease in motor efficiency. Summary of the Invention
[0007] In view of this, the present invention provides a coaxial high-temperature pump, which solves the leakage problem of traditional high-temperature pumps by coaxial design of the pump body and the motor.
[0008] A coaxial high-temperature pump for transporting high-temperature working fluids includes: a pump body, an electric motor, and a heat dissipation device, where the heat dissipation device is disposed between the pump body and the electric motor; the pump body and the electric motor share the same shaft, the shaft penetrates from inside the electric motor to inside the heat dissipation device and extends into the pump body, the upper end of the shaft is connected to the impeller of the pump body, and the lower end is connected to the motor bearing seat.
[0009] Further, the part of the shaft located inside the electric motor and the stator of the electric motor are immersed in the coolant. A coolant inlet is provided at the lower part of the heat dissipation device, and a coolant outlet is provided at the lower part of the electric motor to realize the internal and external circulation of the coolant.
[0010] Further, the pump body includes a housing, an inner housing, and the impeller, and the impeller is installed in the inner housing.
[0011] Further, the heat dissipation device includes: a device housing, an axial spiral flow channel, and a labyrinth flow channel. The upper end of the device housing is connected to the housing of the pump body, and the lower end is connected to the housing of the motor; the axial spiral flow channel is configured to enable the circulation of the high-temperature working fluid by its own flow for heat dissipation; the labyrinth flow channel is used to extend the cooling path and increase the turbulence effect to improve the heat transfer efficiency.
[0012] Further, the axial spiral flow channel is formed on the inner wall of the device housing around the shaft; the labyrinth flow channel is arranged on the end plate of the inner housing of the pump body and is distributed radially, wherein the end plate of the inner housing of the pump body is in contact with the top of the device housing.
[0013] Further, when the high-temperature working fluid passes through the labyrinth flow channel and the axial spiral flow channel, a stable axial temperature gradient is formed, so that the thermal expansion of the shaft changes axially with the change of the temperature gradient.
[0014] Further, the axial spiral flow channel extends to the area where the upper end of the shaft is located.
[0015] Further, the inner wall of the flow channels of the axial spiral flow channel and the labyrinth flow channel is made of a material with a high thermal conductivity coefficient, and the outer wall is made of a material with a low thermal conductivity coefficient.
[0016] Further, a high-temperature resistant coating is sprayed on the surface of the stator.
[0017] Further, the iron core of the stator is designed with heat dissipation fins.
[0018] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows: The present invention designs the pump body and the motor coaxially and shares a single shaft. This not only reduces the vibration and thermal expansion deviation of the traditional coupling (used to connect the pump shaft and the motor shaft), but more importantly, it can eliminate the mechanical seal and directly use the bearing housing to fix this shaft, fundamentally solving the leakage problem. However, due to sharing a single shaft, the upper end of the shaft is in a high-temperature environment, and heat is easily transferred axially to the motor. Therefore, the present invention designs a heat dissipation device to control the temperature of the shaft in the high-temperature environment and limit the axial transfer of heat to the motor to ensure the stable operation of the coaxial high-temperature pump of the present invention.
[0019] In a further technical solution of the present invention, based on the coaxial design, an axial spiral flow channel and a radially distributed labyrinth flow channel are designed, and the thermal expansion direction is jointly controlled through the temperature gradient, material cooperation, and structural limitation to compensate for the axial deformation at high temperatures.
[0020] In a further technical solution of the present invention, the inner wall of the flow channel is made of a material with a high thermal conductivity coefficient, and the outer wall is made of a material with a low thermal conductivity coefficient. Heat is directionally exported through the difference in the heat transfer coefficient of the materials, restricting the heat conduction from the pump casing to the motor.
[0021] In a further technical solution of the present invention, the labyrinth flow channels radially distributed on the end plate of the inner shell of the pump body are designed to extend the cooling flow channels; the axial spiral flow channels formed in the device casing of the heat dissipation device also extend the cooling flow channels. Combined with the heat conduction difference between the inner and outer heat-conducting materials of the flow channels for collaborative heat dissipation, a temperature gradient is formed on the outer wall of the pump casing. The temperature gradient forms a stable and smoothly decreasing heat dissipation channel.
[0022] On the other hand, the combined use of materials with a higher thermal conductivity coefficient and materials with a lower thermal conductivity coefficient, combined with the integrated design of the flow channels, guides the heat dissipation gradient through the difference in the heat exchange performance of the materials, avoids the formation of excessive thermal stress, reduces the thermal shock caused by the thermal expansion and contraction of the materials, emphasizes the material stability while strictly controlling the heat dissipation, and ensures the equipment stability. Brief Description of the Drawings
[0023] Figure 1 is a schematic structural diagram of the coaxial high-temperature pump according to an embodiment of the present invention.
[0024] Figure 2 is a schematic diagram of the positions of the axial spiral flow channel and the labyrinth flow channel according to an embodiment of the present invention.
[0025] Figure 3 is a schematic diagram of the axial spiral flow channel according to an embodiment of the present invention.
[0026] Figure 4 is a schematic diagram of the labyrinth flow channel according to an embodiment of the present invention.
[0027] Description of the Reference Numerals: 1 - pump body, 10 - outer shell, 11 - inner shell, 12 - impeller; 2 - motor, 20 - housing, 21 - inlet, 22 - outlet, 23 - bearing seat; 3 - heat dissipation device, 30 - device casing, 31 - axial spiral flow channel, 310 - inner wall, 32 - labyrinth flow channel; 4 - shaft. Detailed Embodiments
[0028] The present invention will be further described below in conjunction with the drawings, specific embodiments, and examples. The purpose of providing the examples is only for illustration and not for any limitation.
[0029] In addition, the spatial orientation terms such as "upper", "lower", "left", "right", "top", and "bottom" used in the description of the technical solution of the present invention are for facilitating the description of the relative positional relationship between the components of the product, and do not mean that the product has only the orientation shown in the figure. During actual use, as the orientation of the product changes (for example, rotating 90 degrees or other orientations), the spatial-related descriptions used to describe its orientation should also be explained in a similar manner.
[0030] An embodiment of the present invention provides a coaxial high-temperature pump. Please refer to Figure 1 . This high-temperature pump includes three main components: a pump body 1, a motor 2, and a heat dissipation device 3. The coaxial high-temperature pump in the embodiment of the present invention is of a vertical structure, and from top to bottom, there are the pump body 1, the heat dissipation device 3, and the motor 2 in sequence. Specifically, the pump body 1 includes a housing 10, an inner housing 11, and an impeller 12, and the impeller 12 is installed in the inner housing 11; the motor 2 includes a housing 20, a coolant inlet 21 and an outlet 22 provided on the housing, a bearing seat 23, and other known components such as a stator and a rotor (not shown); the heat dissipation device 3 includes a device housing 30, an axial spiral flow channel 31, and a labyrinth flow channel 32. The heat dissipation device 3 is provided between the pump body 1 and the motor 2. The upper end of the device housing 30 of the heat dissipation device 3 is connected to the housing 10 of the pump body 1, and the lower end is connected to the housing 20 of the motor 2. In the high-temperature pump of the embodiment of the present invention, the pump body 1 and the motor 2 share a common shaft 4. The shaft 4 passes through the inside of the motor 2 to the inside of the heat dissipation device 3 and extends into the pump body 1. The upper end of the shaft 4 is connected to the impeller 12 of the pump body, and the lower end is connected to the motor bearing seat 23. The coaxial design of the high-temperature pump in the embodiment of the present invention controls the direction of thermal expansion to compensate for axial deformation.
[0031] Please refer to Figures 1 to 3 . The axial spiral flow channel 31 is formed on the inner wall of the device housing 30 around the shaft 4, that is, the shaft 4 passes through the inner cavity of the axial spiral flow channel 31. Preferably, the upper end of the axial spiral flow channel 31 extends to the area where the upper end of the shaft 4 is located. The flow channel inlet of the axial spiral flow channel 31 is located at the upper end face where the inner housing of the pump body is connected to the shaft 4, and the outlet is located at about 2 / 3 of the position from top to bottom of the heat dissipation device. The axial spiral flow channel 31 can achieve circulating heat dissipation by the flow of the high-temperature working fluid therein.
[0032] Please refer to Figure 1 , Figure 2 and Figure 4 . The labyrinth flow channel 32 is provided on the end plate of the inner housing 31 of the pump body 1 and is distributed radially. From a top-down view, it is a segmented labyrinth flow channel formed by multiple concentric circles; wherein, the end plate of the inner housing 31 of the pump body 1 is the component that contacts the top of the device housing 30. As shown in Figure 4 , the high-temperature working fluid enters the labyrinth flow channel from the inlet below the impeller 12 and then flows out of the labyrinth flow channel at the position where the shaft 4 is located. The segmented labyrinth flow channel 32 can extend the cooling path and increase the turbulence effect, thereby improving the heat transfer efficiency.
[0033] In a further embodiment of the present invention, the inner walls of the axial spiral flow channel 31 and the labyrinth flow channel 32 are made of materials with a relatively high thermal conductivity, while the outer walls are made of materials with a relatively low thermal conductivity. By utilizing this thermal conductivity difference, the directional export of heat is achieved (allowing heat to conduct from the inner wall of the flow channel to the outer wall as much as possible, rather than axially to the motor), so as to limit the conduction of heat in the pump casing to the motor. On the other hand, the high-thermal-conductivity material on the inner wall of the flow channel at the upper end of the shaft close to the high-temperature environment can absorb heat.
[0034] The core of controlling the thermal expansion direction based on coaxial design to compensate for axial deformation in the embodiment of the present invention is to convert the radial expansion of the shaft and the shaft sleeve into a controllable axial displacement through the difference in the coefficient of thermal expansion of materials, so as to offset the axial deformation at high temperatures. The specific principle is as follows:
[0035] 1) Temperature gradient
[0036] For the high-temperature working medium entering the pump body, in addition to most of the high-temperature working medium transported by the impeller, a small part of the high-temperature working medium passes through the labyrinth flow channel and the axial spiral flow channel in sequence, and a stable temperature gradient is formed on the outer wall of the pump casing. Under this temperature gradient, the thermal expansions of the shaft and the heat dissipation device material (the coefficients of thermal expansion of the two are close) show a stable downward trend. That is, the amount of thermal expansion changes with the change of the temperature gradient, that is, axial change;
[0037] 2) Material matching
[0038] As Figure 4 shown, at the high-temperature end (pump body end), the material matching of the static and dynamic components (the impeller 12 is a dynamic component, and the end plate 110 of the inner casing of the pump body is a static component) utilizes the difference in the coefficients of thermal expansion of different materials. That is, when thermally expanded, the expansion amounts and expansion directions of the static and dynamic components are the same, so as to ensure that the axial deformation at high temperatures is within a controllable range and will not damage the static-dynamic cooperation and the dynamic balance of the shaft.
[0039] 3) Structural limitation
[0040] At high temperatures, by means of the expansion difference formed by the material structure, the radial expansion of the shaft is restricted through the spiral geometric constraint of the axial spiral flow channel and converted into axial displacement, preventing radial wear and damage to the shaft.
[0041] The high-temperature pump in the embodiment of the present invention also adopts a high-temperature-resistant wet stator. Specifically, please refer to Figure 1 , the inner cavity of the motor 2 is filled with a coolant, the part of the shaft 4 located inside the motor is immersed in the coolant, and at the same time, the stator of the motor is also immersed in the coolant to force heat exchange of the coolant. The coolant circulates in and out through the inlet 21 and the outlet 22 provided on the motor housing 20, and the dual functions of self-lubrication and heat dissipation of the motor can be achieved. Preferably, the surface of the stator winding is coated with a high-temperature-resistant coating with good temperature resistance; the stator core is designed with heat dissipation fins to optimize the medium flow path to enhance heat dissipation.
[0042] In the high-temperature pump according to the embodiment of the present invention, by adopting a coaxial design of the motor and the pump, not only the vibration caused by the traditional coupling is reduced, but also the problem of high-temperature working medium leakage is solved because the mechanical seal is cancelled. In order to prevent the part of the shared shaft at the high-temperature end from transferring too much heat to the motor end and ensure the stable operation of the high-temperature pump, the embodiment of the present invention designs an integrated heat dissipation device, which integrates a variety of heat dissipation and cooling methods to strictly control the conduction of the temperature of the hot working medium at the pump end to the motor end. These heat dissipation and cooling methods include:
[0043] The labyrinth flow channel design at the pump end to extend the cooling flow channel;
[0044] The axial spiral flow channel design in the area near the upper end of the shaft to extend the cooling flow channel;
[0045] The built-in cooling water of the motor for further temperature reduction;
[0046] Spraying a material with a high thermal conductivity coefficient on the inner wall of the flow channel to absorb the heat generated by the seal friction, and combining with the coolant circulation in the spiral flow channel to achieve the dual functions of self-lubrication and heat dissipation.
[0047] The working process of the coaxial high-temperature pump according to the embodiment of the present invention is as follows:
[0048] 1. The high-temperature working medium enters the pump body from the pump body inlet and drives the impeller to rotate;
[0049] 2. Most of the high-temperature working medium flows out from the pump body outlet to achieve transportation; and a small part of the high-temperature working medium entering the labyrinth flow channel and the axial spiral flow channel is cooled due to the extension of the flow channel and flows out from the outlets of each flow channel, playing the role of temperature reduction and preventing leakage into the motor cavity;
[0050] 3. The materials with high / low thermal conductivity coefficients cooperate to conduct heat, and the material with high thermal conductivity coefficient absorbs the residual heat in the seal cavity;
[0051] 4. The high-temperature resistant coating on the surface of the stator winding; the design of the heat dissipation fins of the iron core; and the forced cooling water for further cooling.
[0052] Compared with the prior art, the advantages of the coaxial high-temperature pump according to the embodiment of the present invention are reflected in:
[0053] 1. The heat dissipation gradient design improves the heat dissipation stability and efficiency:
[0054] - The labyrinth flow channel design at the pump end extends the cooling flow channel, and the temperature of the high-temperature working medium becomes lower as it passes through this flow channel;
[0055] - The axial spiral flow channel built in the heat dissipation device extends the cooling path, and cooperates with the poor thermal conductivity of the material for heat dissipation. A temperature gradient is formed on the outer wall of the pump shell. The temperature gradient is smooth and the transition is clear, avoiding the single traditional cooling means, resulting in weak temperature control points; and the sudden change of the temperature gradient, resulting in additional thermal stress.
[0056] - The integrated design of the phase change material and the flow channel, by virtue of the poor heat exchange performance of the material, guides the heat dissipation gradient, avoids the formation of excessive thermal stress, reduces the impact on the material, emphasizes the material stability while strictly controlling heat dissipation, and ensures the equipment stability.
[0057] 2. Extended lifespan:
[0058] - The corrosion resistance of the wet stator coating is improved, and the insulation lifespan is extended to more than twice that of the traditional design;
[0059] - The temperature of the shaft end seal cavity is stabilized below 150 °C (up to 250 °C in the traditional solution), and the aging cycle of the O-ring is extended by 50%.
[0060] 3. Enhanced operation stability:
[0061] - The coaxial drive reduces the vibration amplitude (by more than 35%);
[0062] - By controlling the direction of thermal expansion, the axial deformation at high temperatures is controlled. The shaft stability is significantly strengthened, and it can adapt to the working conditions of multiple and frequent starts and stops. The equipment adaptability is higher.
[0063] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those skilled in the technical field to which the present invention belongs, without departing from the concept of the present invention, several equivalent substitutions or obvious variations can be made, and as long as the performance or use is the same, they should all be regarded as belonging to the protection scope of the present invention.
Claims
1. A coaxial high-temperature pump for transporting high-temperature working medium, characterized in that, Comprising: A pump body (1), a motor (2) and a heat dissipation device (3), the heat dissipation device (3) being arranged between the pump body (1) and the motor (2); the pump body (1) and the motor (2) share the same shaft (4), the shaft (4) penetrates from inside the motor to inside the heat dissipation device and extends into the pump body, the upper end of the shaft is connected to the impeller (12) of the pump body, and the lower end is connected to the motor bearing seat (23).
2. The coaxial high-temperature pump according to claim 1, wherein The part of the shaft (4) located inside the motor and the stator of the motor are immersed in the coolant. A coolant inlet (21) is provided at the lower part of the heat dissipation device (3), and a coolant outlet (22) is provided at the lower part of the motor (2) to realize the internal and external circulation of the coolant.
3. The coaxial high-temperature pump according to claim 1 or 2, characterized in that, The pump body (1) includes a housing (10), an inner housing (11) and the impeller (12), and the impeller (12) is installed in the inner housing (11).
4. The coaxial high-temperature pump according to claim 3, characterized in that, The heat dissipation device (3) includes: a device housing (30), an axial spiral flow channel (31) and a labyrinth flow channel (32). The upper end of the device housing (30) is connected to the housing (10) of the pump body, and the lower end is connected to the housing (20) of the motor; the axial spiral flow channel (31) is arranged to realize circulation heat dissipation by using the self-flow of the high-temperature working medium; the labyrinth flow channel (32) is used to extend the cooling path and increase the turbulence effect to improve the heat exchange efficiency.
5. The coaxial high-temperature pump according to claim 4, characterized in that, The axial spiral flow channel (31) is formed on the inner wall of the device housing (30) around the shaft (4); the labyrinth flow channel (32) is arranged on the end plate of the inner housing (31) of the pump body and is distributed radially, wherein the end plate of the inner housing (31) of the pump body is in contact with the top of the device housing (30).
6. The coaxial high-temperature pump according to claim 5, characterized in that, When the high-temperature working medium passes through the labyrinth flow channel (32) and the axial spiral flow channel (31), a stable axial temperature gradient is formed, so that the thermal expansion of the shaft (4) changes axially with the change of the temperature gradient.
7. The coaxial high-temperature pump according to claim 4, wherein The axial spiral flow channel (31) extends to the area where the upper end of the shaft (4) is located.
8. The coaxial high-temperature pump according to claim 4, characterized in that, The inner walls of the flow channels of the axial spiral flow channel (31) and the labyrinth flow channel (32) are made of materials with high thermal conductivity, and the outer walls are made of materials with low thermal conductivity.
9. The coaxial high-temperature pump according to claim 2, wherein, The surface of the stator is sprayed with a high-temperature resistant coating.
10. The coaxial high-temperature pump according to claim 2, characterized in that, The iron core of the stator is designed with heat dissipation fins.