Wear-resistant corrosion-resistant water pump

Abstract

The present application relates to the technical field of water pump, in particular to a kind of anti-abrasion corrosion-resistant water pump, including pump body, the suction line being connected to the water inlet of pump body, the inside of suction line is provided with thermal induced diameter change structure, when the temperature of medium flowing reaches expansion threshold, thermal induced diameter change structure produces radial expansion, and first flow path is closed, and medium only flows from suction line to pump body via second flow path.This application, when water pump is in small flow condition, too small medium flow cannot take away heat accumulated in pump in time, at this time, thermal induced diameter change structure can rely on its own double memory effect to adapt radial expansion, cooperate with the elastic gasket of variable diameter section inner wall to realize reliable sealing and closing of first flow path, medium can only pass through second flow path and form jet, act on high temperature sensitive area in pump prone to heat accumulation, inhibit corrosion reaction acceleration caused by temperature rise.

Description

Technical Field

[0001] This invention relates to the field of water pump technology, and more specifically, to a wear-resistant and corrosion-resistant water pump. Background Technology

[0002] As a core device for fluid transportation, water pumps are widely used in municipal water supply and drainage, industrial circulation and other fields. Their operational stability and service life directly affect the working efficiency and maintenance cost of the entire system. Among them, the flow-through components are the core structures of the water pump that are in direct contact with the transported medium and are subjected to the action of fluid for a long time. Their wear resistance and corrosion resistance are the key indicators that determine the overall reliability of the water pump.

[0003] Water pumps rely on the high-speed rotation of the impeller to generate centrifugal force, converting mechanical energy into the pressure and kinetic energy of the fluid, thereby achieving continuous transport of the medium. Under rated operating conditions, the medium flows stably along the preset flow channel, the flow field distribution inside the pump is uniform, heat and medium can be discharged normally, and the physical erosion and chemical corrosion of the flow components are within a controllable range. However, in actual engineering applications, due to factors such as process flow regulation and oversized equipment selection, water pumps are prone to operating at low flow rates far below the rated flow rate. For example, when municipal water supply experiences a sudden drop in water consumption at night or when production lines in industrial parks operate at half load, water pumps will deviate from the rated flow rate and remain in a low-flow operating state for extended periods. When a water pump operates at low flow rates, the flow velocity of the medium decreases. If the medium contains corrosive components, the slow flow rate prolongs the residence time of the medium in the pump chamber, impeller, and flow channel, leading to a more complete electrochemical corrosion reaction and exacerbating corrosion damage to the flow components. Simultaneously, the insufficient flow rate cannot effectively remove the heat generated during pump operation, causing a continuous rise in pump temperature. This increased temperature further accelerates the electrochemical reaction rate, intensifying corrosion. Therefore, a wear-resistant and corrosion-resistant water pump is urgently needed to address these issues. Summary of the Invention

[0004] This invention provides a wear-resistant and corrosion-resistant water pump. By incorporating a thermally induced diameter-changing structure within the suction pipe, the pump can adaptively switch the flow path state according to temperature. Under normal rated operating conditions, it maintains parallel and unobstructed flow in both directions, ensuring stable low-resistance delivery of the medium. Under low-flow, heat-accumulating conditions, it automatically closes the bypass and narrows the main flow path to form a high-speed jet, enhancing internal heat dissipation and inhibiting accelerated corrosion and wear. This solves the problems mentioned in the background section, namely: Water pumps are used for transporting media. Under rated operating conditions, wear and corrosion are controllable. However, in reality, due to factors such as process adjustment and oversized selection, they are often used under low flow conditions, which can easily aggravate wear and corrosion of the flow-through components.

[0005] To achieve the above objectives, the wear-resistant and corrosion-resistant water pump includes a pump body, which includes a pump casing. A pump chamber is formed inside the pump casing, and an impeller is installed inside the pump chamber. A pump shaft is connected to the drive side of the impeller, and the other end of the pump shaft is connected to a drive motor. The pump body inlet is connected to a suction pipe, and the pump body outlet is connected to an outlet pipe. A thermo-induced diameter-changing structure is provided inside the suction pipe, which can generate radial expansion when the temperature of the flowing medium reaches a set threshold. When the temperature of the flowing medium is lower than the expansion threshold, the thermo-variable diameter structure is in the first working state. A first flow path is formed between the thermo-variable diameter structure and the suction pipe, and a second flow path is formed inside the thermo-variable diameter structure. The medium flows from the suction pipe to the pump body through the first flow path and the second flow path at the same time. When the temperature of the flowing medium reaches the expansion threshold, the thermo-induced diameter change structure generates radial expansion and closes the first flow path, so that the medium flows from the suction pipe to the pump body only through the second flow path.

[0006] The above technical solution can adaptively switch the flow path and flow cross section according to the medium temperature, ensuring stable medium delivery under normal operating conditions and reducing additional flow resistance. In addition, it can automatically adjust the flow field under low flow temperature rise conditions, improve heat dissipation and flow state inside the pump, thereby effectively reducing wear and corrosion caused by low flow operation.

[0007] Based on this, the inside of the suction pipe is a variable diameter section on the side near the pump body, the thermally induced variable diameter structure is located inside the variable diameter section, a recovery section is provided between the variable diameter section and the pump body, and the end of the variable diameter section away from the pump body in the suction pipe is the upstream section.

[0008] By dividing the suction pipeline into an upstream section, a variable diameter section, and a recovery section, a suitable installation space can be provided for the thermally induced variable diameter structure. At the same time, the medium can enter the pump body smoothly after the flow channel is regulated, avoiding flow field disturbance and ensuring stable and reliable flow channel switching and flow regulation processes.

[0009] Furthermore, the thermally induced diameter-changing structure includes a diameter-changing component, which has a spiral structure. The internal hollow channel of the diameter-changing component forms the second flow path, and the gap between the outer edge of the diameter-changing component and the inner wall of the diameter-changing section forms the first flow path. Both ends of the reducing component are fixedly installed with support rods, and the other ends of the two support rods are fixedly connected to the inner wall of the suction pipe, which is used to coaxially position the reducing component inside the reducing section.

[0010] Preferably, the variable diameter component is made of a shape memory alloy with a two-way memory effect, which can expand radially when the temperature of the flowing medium reaches the expansion threshold of the variable diameter component.

[0011] The support rod is made of a corrosion-resistant metal material and is used to provide axial positioning when the variable diameter component expands radially; Furthermore, the upstream section is a straight pipe structure, and the length of the upstream section is 3-5 times the inner diameter of the suction pipe.

[0012] In another technical solution, the inner wall of the variable diameter section is provided with an annular inner groove, and an elastic gasket is installed inside the inner groove. When the variable diameter component is heated and radially expanded in the second working state, the outer edge of the variable diameter component squeezes the gasket, causing the gasket to undergo elastic deformation and fill the gap between the variable diameter component and the inner wall of the variable diameter section, thereby achieving the interception and sealing of the first flow path.

[0013] The surface of the gasket facing the variable diameter component has fine textures, which are used to increase the contact area and sealing pressure when the variable diameter component is extruded.

[0014] This technical solution, by setting an elastic gasket with micro-textures on the inner wall of the variable diameter section, can form a tight seal with the variable diameter component when it expands, fill the gap, increase the sealing pressure, and reliably seal the first flow path, ensuring the accuracy and stability of the flow channel switching.

[0015] In addition, at least one clamping ring is provided on the outer wall of the suction pipe. The clamping ring is connected to the external foundation through a support member to fix the suction pipe and reduce pipe vibration caused by the operation of the thermo-induced diameter change structure.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The wear-resistant and corrosion-resistant water pump has a thermo-induced diameter change structure made of shape memory alloy inside the suction pipe. Under normal rated operating conditions where the medium temperature has not reached the expansion threshold, the thermo-induced diameter change structure maintains its initial shape, and the first flow path and the second flow path remain unobstructed at the same time. The medium can flow into the pump chamber in parallel through two paths. The overall flow resistance is small and will not have an adverse effect on the normal pumping efficiency and medium delivery capacity of the water pump. 2. When the water pump is operating at a low flow rate, the portion of its input shaft power that is not converted into fluid kinetic energy will continue to be converted into heat. The low medium flow rate cannot remove the heat accumulated in the pump in time, causing the medium flowing through it to be heated to the set expansion threshold. At this time, the thermally induced diameter-changing structure can adaptively expand radially by relying on its own two-way memory effect. With the help of the elastic gasket on the inner wall of the diameter-changing section, it can reliably seal the first flow path. The medium can only pass through the second flow path and form a jet. The high-speed medium acts on the high-temperature sensitive area in the pump that is prone to heat accumulation, enhances the convective heat transfer effect and quickly strips away the heat accumulated on the wall surface, inhibiting the accelerated corrosion reaction caused by temperature rise. It simultaneously improves the corrosion resistance under low flow rate conditions from the aspects of flow field regulation and heat dissipation enhancement. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the medium flow direction during the operation of the water pump body in this invention; Figure 3 This is a schematic diagram of the internal structure of the suction tubing in this invention; Figure 4 This is a schematic diagram of the internal region division structure of the suction pipe in this invention; Figure 5 This is a side view of the pump body in state one of the present invention. Figure 6 This is a schematic diagram of the medium flow direction in Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the cross-sectional structure of the inhalation tubing in Embodiment 1 of the present invention; Figure 8 This is a side view of the water pump body in state two of the present invention. Figure 9 This is a schematic diagram of the medium flow direction in Embodiment 2 of the present invention; Figure 10 This is a cross-sectional schematic diagram of the inhalation tubing in Embodiment 2 of the present invention.

[0018] The meanings of the labels in the diagram are as follows: 1. Pump body; 11. Pump body; 12. Suction pipe; 13. Discharge pipe; 14. Support components; 15. Clamping ring; 2. Thermally induced diameter change structure; 20. Gasket; 201. Inner groove; 21. Variable diameter component; 22. Support rod; 23. Recovery section; 24. Variable diameter section; 25. Upstream section; 241. First distribution path; 242. Second distribution path. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In existing technologies, water pumps rely on the high-speed rotation of the impeller to generate centrifugal force, converting mechanical energy into the pressure and kinetic energy of the fluid, thereby achieving continuous transport of the medium. Under rated operating conditions, the medium flows stably along the preset flow channel, the flow field distribution inside the pump is uniform, and the generated heat can be discharged normally with the medium. The physical erosion and chemical corrosion of the flow components are also within a controllable range. However, in actual engineering applications, due to factors such as process flow regulation and oversized equipment selection, water pumps are prone to operate at low flow rates below the rated flow rate. For example, when the municipal water supply suddenly reduces water consumption at night or when the production line in an industrial park operates at half load, the water pump will deviate from the rated flow rate and remain in a low flow rate state for a long time. Under this condition, the reduced flow rate of the transported medium will lead to a longer residence time of corrosive substances inside the pump, making electrochemical corrosion more severe. In addition, the insufficient flow rate cannot remove the heat inside the pump in time, and the temperature rise will further accelerate the corrosion reaction.

[0021] Example 1: This example provides a wear-resistant and corrosion-resistant water pump. (See attached document.) Figures 1-3 As shown, the pump includes a pump body 1, which includes a pump body 11. A pump chamber is formed inside the pump body 11, and an impeller is installed inside the pump chamber. A pump shaft is connected to the drive side of the impeller, and the other end of the pump shaft is connected to a drive motor. The inlet of the pump body 11 is connected to a suction pipe 12, and the outlet of the pump body 11 is connected to an outlet pipe 13. A thermo-induced diameter-changing structure 2 is provided inside the suction pipe 12. The thermo-induced diameter-changing structure 2 can generate radial expansion when the temperature of the flowing medium reaches a set threshold (this threshold is determined according to the material selected by the thermo-induced diameter-changing structure 2), thereby realizing adaptive control of the flow state of the flow channel. Specifically, when the temperature of the flowing medium is lower than the expansion threshold, the thermo-induced diameter change structure 2 is in the first working state: a first flow path 241 is formed between the thermo-induced diameter change structure 2 and the suction pipe 12, and a second flow path 242 is formed inside the thermo-induced diameter change structure 2. The medium flows from the suction pipe 12 to the pump body 11 through the first flow path 241 and the second flow path 242 at the same time. The parallel flow of the two paths can reduce the flow resistance, so that the pump body 1 can stably transport the medium under normal working conditions.

[0022] Combination Figure 4 As shown, in the suction pipe 12, a section of the pipe near the pump body 11 is configured as a variable diameter section 24 (as shown in the attached diagram). Figure 4(Region b), the thermally induced diameter change structure 2 is installed entirely within the internal space of the diameter change section 24. A recovery section 23 (as shown in the attached diagram) is provided between the diameter change section 24 and the inlet of the pump body 11. Figure 4 In area a), the pipe section 24 away from the pump body 11 is the upstream section 25 of the suction pipe 12 (as shown in the attached diagram). Figure 4 (In area c), each section of the pipeline is connected in sequence to form a complete suction pipeline 12 flow channel.

[0023] The segmented structure provides corresponding installation space for the thermally induced diameter change structure 2. The upstream section 25 allows the medium to maintain a stable flow state before entering the diameter change section 24. The diameter change section 24 provides suitable space conditions for the radial expansion action of the thermally induced diameter change structure 2. After the medium completes the flow channel switching in the diameter change section 24, the flow state can be gradually regulated through the recovery section 23 before being transported into the pump body 11, so that the medium flow process matches the working state of the thermally induced diameter change structure 2 and maintains the continuity of the medium flow in the flow channel.

[0024] The aforementioned thermo-induced diameter-changing structure 2 mainly consists of a diameter-changing component 21 and a support rod 22. The diameter-changing component 21 adopts a spiral structure, and its internal hollow channel forms a second flow path 242. The gap between the outer edge of the diameter-changing component 21 and the inner wall of the diameter-changing section 24 forms a first flow path 241. The two ends of the diameter-changing component 21 are respectively connected to the support rod 22, and the other end of the support rod 22 is fixed to the inner wall of the suction pipe 12, thereby coaxially setting the diameter-changing component 21 inside the diameter-changing section 24. With this structural configuration, when the medium temperature is below the expansion threshold in the first working state, the reducing component 21 maintains its initial shape, and both the first flow path 241 and the second flow path 242 are in a conductive state. The medium can flow through the reducing section 24 simultaneously through the two flow paths. In this flow mode, the two paths together form the flow cross section, which can match the medium conveying requirements under normal operating conditions of the water pump. The coaxial positioning of the support rod 22 makes the gap between the reducing component 21 and the inner wall of the reducing section 24 uniformly distributed, and the medium can maintain a stable flow state during the flow process, thus not affecting the normal medium flow process of the water pump.

[0025] The reducing component 21 is made of titanium-nickel (NiTi) shape memory alloy, a mature two-pass thermotropic memory alloy used in existing fluid temperature control structures, possessing stable temperature phase change and deformation response characteristics. When the pump body 1 operates under normal rated conditions, the medium it transports is mostly room temperature fluid, with the medium temperature typically stable between 20℃ and 40℃. This temperature range is below the austenitic phase transformation threshold of the titanium-nickel alloy. At this time, the reducing component 21 maintains the contraction shape of the martensitic phase, while the radial dimension of the spiral wire is relatively small. The first flow path 241 between the outer edge of the reducing component 21 and the inner wall of the reducing section 24 retains sufficient annular gap, which, together with the internal second flow path 242, forms a large total flow cross-section, which can match the medium transport flow rate under normal operating conditions.

[0026] The support rod 22 is made of 316L stainless steel, which has sufficient structural rigidity and mechanical stability, and also has good corrosion resistance in the medium transportation environment. The two ends of the reducing component 21 are fixedly connected to one end of the support rod 22 by end welding. The welding point is only set in the non-deformation area at the end of the reducing component 21 and does not cover the main spiral section of the reducing component 21 used for radial expansion. The other end of the two support rods 22 away from the reducing component 21 is fixed to the inner wall of the suction pipe 12, thereby coaxially positioning the reducing component 21 inside the reducing section 24.

[0027] Based on this, the upstream section 25 adopts a straight pipe structure, and its length is set to be 3-5 times the inner diameter of the suction pipe 12. This value is determined based on the theory of inlet section length of circular pipes in fluid mechanics and the engineering design experience of centrifugal pump suction pipe 12. Specifically, under rated operating conditions, the medium flows through the suction pipe 12 at the design flow rate. At this time, the flow velocity is high, the Reynolds number is large, and the flow inside the pipe is mostly in a fully developed turbulent state. For a circular straight pipe in turbulent state, the medium needs to flow through an inlet section of about 3-4 times the inner diameter to form a stable velocity distribution profile. In order to ensure that the turbulence of the downstream flow field of the obstacle does not interfere with the impeller inlet, and to maintain the relatively stable flow at the pump inlet after the jet is formed under low flow conditions, the length of the upstream section 25 is set to 3-5 times the inner diameter. This can provide the necessary stable flow development distance for the medium before entering the variable diameter section 24 while taking into account the compact installation space. At the same time, this length will not occupy too much installation space due to excessive length, which is in line with the engineering practice of the overall layout of the pump pipeline.

[0028] The straight pipe structure and size settings allow the medium to gradually develop its flow state in the upstream section 25, making the flow velocity distribution of the medium tend to be uniform, providing stable inflow conditions for the subsequent flow into the variable diameter section 24, maintaining the continuity of the medium flow in the suction pipe 12, and providing a stable flow basis for the operation of the thermally induced variable diameter structure 2.

[0029] Based on this, at least one clamping ring 15 is installed on the outer wall of the suction pipe 12 by clamping. The clamping ring 15 is connected to the support member 14, and the support member 14 is fixedly connected to the external foundation. The positioning of the pipe is achieved by the cooperation between the clamping ring 15 and the suction pipe 12. At the same time, the vibration transmitted to the pipe during the operation of the thermo-induced diameter change structure 2 is transmitted by relying on the support member 14 and the external foundation.

[0030] Specifically, the clamping ring 15 provides multi-point fixation for the suction pipe 12, the support member 14 can transfer the force on the suction pipe 12 to the external foundation, the suction pipe 12 can maintain the predetermined installation position during the operation of the thermo-induced diameter change structure 2, the vibration state of the pipe can be transmitted to the external foundation through the support member 14 for dispersion, and maintain the matching state of the connection between the suction pipe 12 and the pump body 11.

[0031] Example 2: Unlike Example 1 above, when the temperature of the flowing medium reaches the expansion threshold, the thermally induced variable diameter structure 2 generates radial expansion and closes the first flow path 241. The medium flows from the suction pipe 12 to the pump body 11 only through the second flow path 242. By narrowing the flow channel, a high-speed jet is formed, which enhances heat dissipation inside the pump body 1 and inhibits abnormal aggravation of wear and corrosion under low flow conditions.

[0032] It is important to note that the reason why the water pump body 1 generates a lot of heat when operating under low flow conditions is mainly due to the imbalance between energy conversion and loss. When the water pump body 1 is running, the drive motor converts electrical energy into shaft power and transfers it to the impeller. The impeller then converts mechanical energy into the pressure energy and kinetic energy of the medium to achieve transportation. Under rated flow conditions, the sufficient medium flow allows most of the shaft power to be converted into effective fluid power. Only a small amount of energy is converted into heat energy due to fluid friction, turbulence disturbance, and seal friction. Moreover, this trace amount of heat can be carried away by the fast-flowing medium in time. However, under low flow conditions, the medium transportation volume is reduced, and the effective fluid power output by the impeller is much less than the input shaft power. A large amount of unutilized mechanical energy will continue to accumulate in the pump in the form of heat energy. In addition, the medium flow rate is too slow, which leads to a decrease in heat dissipation capacity. The heat generation rate is much higher than the heat dissipation rate, which ultimately causes the overall temperature inside the pump to rise continuously.

[0033] Under low flow conditions, the heat accumulated inside the pump body 11 will gradually be transferred to the suction pipe 12 and increase the temperature of the medium inside the pipe. As the core area for heat generation, the pump chamber and impeller cannot be quickly discharged with the medium under low flow conditions and will continue to accumulate inside the pump body 11. The temperature of the medium inside the pump will gradually rise to 50℃~65℃. Since both the pump body 11 and the suction pipe 12 are made of metal, they have good thermal conductivity. The heat inside the pump will first be transferred to the connection between the pump body 11 and the suction pipe 12 through thermal conduction, and then continuously conducted outward along the pipe wall of the suction pipe 12. At the same time, the medium in the suction pipe 12 will have a significantly reduced flow rate due to the low flow rate, and the residence time in the pipe will be correspondingly extended. This will cause the medium flowing through this area to continuously undergo thermal convection with the heated pipe wall of the suction pipe 12 and absorb heat. The medium that cannot flow out quickly will continuously accumulate heat, eventually causing the temperature of the room temperature medium in the suction pipe 12 to gradually rise.

[0034] Since the pump body 11 and the suction pipe 12 are metal interconnected structures with good thermal conductivity, the heat accumulated in the pump chamber is transferred to the suction pipe 12 through heat conduction through the pipe wall, causing the temperature of the medium in the suction pipe 12 to rise synchronously. When the temperature reaches the phase transformation expansion threshold of the reducing component 21, the reducing component 21 will undergo a phase transformation from martensite to austenite and generate radial expansion. After expansion, the outer edge of the reducing component 21 fits against the inner wall of the reducing section 24, thereby assisting in the closure of the first flow path 241.

[0035] When the variable diameter component 21 undergoes radial expansion deformation as the medium temperature rises, the support rod 22 can maintain its shape and installation position without shifting due to its own rigidity, and continuously provide reliable positioning support for the variable diameter component 21; at the same time, the support rod 22 only applies axial positioning constraint to the variable diameter component 21, which is perpendicular to the deformation direction of the radial expansion of the variable diameter component 21, and will not interfere with the thermal expansion action of the variable diameter component 21. It can ensure the coaxial positioning of the variable diameter component 21 while reserving sufficient deformation space for its radial expansion.

[0036] Back Figure 3 It can be seen that the inner wall of the variable diameter section 24 is machined with an annular inner groove 201, and the gasket 20 is installed inside the inner groove 201. When the variable diameter part 21 enters the second working state of thermal expansion, its outer edge will exert a squeezing effect on the gasket 20. After being squeezed, the gasket 20 undergoes elastic deformation and fills the fitting gap between the variable diameter part 21 and the inner wall of the variable diameter section 24, thereby assisting in the sealing of the first flow path 241. The fine texture on the surface of the gasket 20 can increase the contact area and sealing pressure during the extrusion process.

[0037] Among them, the gasket 20 is made of fluororubber, which is suitable for the medium temperature range of the water pump in both low flow and normal operating conditions. It also has stable elastic deformation and rebound capabilities. After assembly, the gasket 20 is flush with the opening of the inner groove 201, that is, the surface of the gasket 20 facing the inside of the pipeline is in contact with the inner wall of the suction pipeline 12. The flush setting allows the gasket 20 to not change the flow profile of the inner wall of the variable diameter section 24 when the variable diameter part 21 is not expanded. When the variable diameter part 21 expands, it can directly contact the outer edge of the variable diameter part 21 and deform.

[0038] Furthermore, under low flow conditions, when the medium enters the recovery section 23 through the variable diameter section 24, the recovery section 23 can regulate and transition the flow state of the medium, allowing the medium to gradually transition from the regulated state in the variable diameter section 24 to a stable state. This makes the flow field distribution of the medium entering the pump body 11 more uniform, reduces the impact of flow field fluctuations on the flow state of the impeller inlet inside the pump body 11, and adapts to the medium transportation needs inside the pump body 11. At the same time, in conjunction with the segmented layout of the upstream section 25 and the variable diameter section 24, the flow process of the medium in the suction pipe 12 remains continuous, so that after the thermally induced variable diameter structure 2 completes the flow channel regulation, the medium can enter the pump cavity in a relatively stable flow state, which is compatible with the overall transportation conditions of the water pump.

[0039] It is also important to note that the thermo-induced diameter change structure 2 will not be falsely triggered by temperature rise caused by damage to other components of the water pump. This is because the temperature rise under low flow conditions is a gradual increase covering the entire suction pipe 12, while the temperature rise caused by component damage is only a local and short-term sudden increase, which cannot cause the medium in the suction pipe 12 to heat up as a whole. At the same time, the thermo-induced diameter change structure 2, made of shape memory alloy, only responds to the continuous overall temperature rise of the medium. Combined with the elastic sealing structure of the inner wall of the diameter change section 24, a seal can only be achieved when the thermo-induced diameter change component 21 is fully radially expanded, further eliminating false triggering caused by local short-term temperature rise and ensuring that the structure is accurately triggered only under the target operating condition of low flow heat accumulation.

[0040] Working principle: The water pump body 1 includes a pump body 11, a suction pipe 12, an outlet pipe 13, and a drive component. An impeller is installed inside the pump chamber of the pump body 11, and the impeller is connected to the drive motor via a pump shaft. A thermo-induced diameter-changing structure 2 is installed inside the suction pipe 12. The thermo-induced diameter-changing structure 2 consists of a helical diameter-changing component 21 and a support rod 22. Figure 5 , Figure 6 and Figure 7Under the normal operating conditions shown, the reducing component 21 is in a contracted state of martensitic phase, with a small radial dimension of the spiral wire. Its internal hollow channel forms a second flow path 242, and the gap between the outer edge of the reducing component 21 and the inner wall of the reducing section 24 forms a first flow path 241. The two flow paths are simultaneously open, and the medium flows through the first flow path 241 and the second flow path 242 through the reducing section 24. After passing through the recovery section 23 to regulate the flow state, it enters the pump body 11. The drive motor drives the pump shaft and impeller to rotate, converting mechanical energy into the pressure energy and kinetic energy of the medium, thereby achieving stable medium delivery. like Figure 8 , Figure 9 and Figure 10 Under the low-flow-rate conditions shown, only a small portion of the shaft power input from the motor is converted into the kinetic energy of the medium flow. A large amount of unused mechanical energy is converted into heat and accumulates in the pump chamber. Since both the pump body 11 and the suction pipe 12 are made of metal, the heat is transferred to the suction pipe 12 through thermal conduction, causing the temperature of the medium in the suction pipe 12 to rise, reaching the phase transformation expansion threshold of the titanium-nickel shape memory alloy. At this time, the reducing component 21 undergoes a phase transformation from martensite to austenite and generates radial expansion. Its outer edge presses against the gasket 20 in the inner groove 201 of the reducing section 24. The gasket 20 undergoes elastic deformation and fills the gap between the reducing component 21 and the inner wall of the reducing section 24, realizing the relative flow path 241. When the medium flows only through the second flow path 242, the contraction of the flow area of ​​the flow channel will directly increase the flow velocity of the medium and form a high-speed jet. The high-speed flowing medium can quickly carry away the excess heat accumulated in the pump cavity under low flow conditions and carry it out of the pump body 11 during the medium transportation process, thereby improving the overall heat dissipation efficiency of the pump. At the same time, the high-speed jet can continuously scour the pump body 11, impeller and inner wall of the flow channel, reduce the retention and deposition of the medium on the inner wall of the pump, reduce the wall corrosion caused by local high temperature or long-term adhesion of the medium, and also improve the backflow and turbulence disturbance in the pump under low flow conditions, reduce the continuous scouring of the components by the turbulent flow field, thereby inhibiting the aggravation of wear and corrosion.

[0041] It should be noted that the accompanying drawings in the instruction manual are only used to show the structural assembly relationship of the various components and do not represent the specific length and dimension parameters under actual working conditions.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wear-resistant and corrosion-resistant water pump, comprising a pump body (1), wherein the pump body (1) includes a pump casing (11), a pump cavity is formed inside the pump casing (11), an impeller is installed inside the pump cavity, a pump shaft is connected to the drive side of the impeller, and the other end of the pump shaft is connected to a drive motor, characterized in that: The pump body (11) is connected to the suction pipe (12) through the inlet, and the pump body (11) is connected to the outlet pipe (13) through the outlet. The suction pipe (12) is provided with a thermo-induced diameter change structure (2) inside. The thermo-induced diameter change structure (2) can generate radial expansion when the temperature of the flowing medium reaches a set threshold. When the temperature of the flowing medium is lower than the expansion threshold, the thermo-variable diameter structure (2) is in the first working state, and a first flow path (241) is formed between the thermo-variable diameter structure (2) and the suction pipe (12), and a second flow path (242) is formed inside the thermo-variable diameter structure (2). The medium flows from the suction pipe (12) to the pump body (11) through the first flow path (241) and the second flow path (242). When the temperature of the medium flowing through it reaches the expansion threshold, the thermo-induced diameter change structure (2) expands radially and closes the first flow path (241), and the medium flows from the suction pipe (12) to the pump body (11) only through the second flow path (242).

2. The wear-resistant and corrosion-resistant water pump according to claim 1, characterized in that: The inside of the suction pipe (12) near the pump body (11) is a variable diameter section (24), the thermo-induced variable diameter structure (2) is located inside the variable diameter section (24), and a recovery section (23) is provided between the variable diameter section (24) and the pump body (11). In the suction pipe (12), the end of the variable diameter section (24) away from the pump body (11) is the upstream section (25).

3. The wear-resistant and corrosion-resistant water pump according to claim 2, characterized in that: The thermo-induced diameter-changing structure (2) includes a diameter-changing component (21), which has a spiral structure. The internal hollow channel of the diameter-changing component (21) forms the second flow path (242), and the gap between the outer edge of the diameter-changing component (21) and the inner wall of the diameter-changing section (24) forms the first flow path (241).

4. The wear-resistant and corrosion-resistant water pump according to claim 3, characterized in that: Both ends of the variable diameter component (21) are fixedly installed with support rods (22), and the other ends of the two support rods (22) are fixedly connected to the inner wall of the suction pipe (12) to position the variable diameter component (21) coaxially inside the variable diameter section (24).

5. The wear-resistant and corrosion-resistant water pump according to claim 3, characterized in that: The variable diameter component (21) is made of a shape memory alloy with a two-way memory effect, which can expand radially when the temperature of the medium flowing through it reaches the expansion threshold of the variable diameter component (21).

6. The wear-resistant and corrosion-resistant water pump according to claim 4, characterized in that: The support rod (22) is made of a corrosion-resistant metal material and is used to provide axial positioning when the diameter-changing part (21) expands radially.

7. The wear-resistant and corrosion-resistant water pump according to claim 3, characterized in that: The upstream section (25) is a straight pipe structure, and the length of the upstream section (25) is 3-5 times the inner diameter of the suction pipe (12).

8. The wear-resistant and corrosion-resistant water pump according to claim 3, characterized in that: The inner wall of the variable diameter section (24) is provided with an annular inner groove (201). An elastic gasket (20) is installed inside the inner groove (201). When the variable diameter component (21) is heated and radially expanded in the second working state, the outer edge of the variable diameter component (21) squeezes the gasket (20), causing the gasket (20) to undergo elastic deformation and fill the gap between the variable diameter component (21) and the inner wall of the variable diameter section (24), thereby achieving the interception and closure of the first flow path (241).

9. The wear-resistant and corrosion-resistant water pump according to claim 8, characterized in that: The surface of the gasket (20) facing the variable diameter member (21) is provided with fine textures, which are used to increase the contact area and sealing pressure when the variable diameter member (21) is compressed.

10. The wear-resistant and corrosion-resistant water pump according to claim 1, characterized in that: At least one clamping ring (15) is provided on the outer wall of the suction pipe (12). The clamping ring (15) is connected to the external foundation through the support member (14) to fix the suction pipe (12) and reduce pipe vibration caused by the operation of the thermo-induced diameter change structure (2).

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