Refrigerant-resistant magnetic levitation centrifugal heat pump

Abstract

The utility model discloses a can anti -refrigerant magnetic suspension centrifugal heat pump belongs to heat pump equipment technical field. Including magnetic suspension compressor, magnetic suspension compressor includes casing, stator, rotor, stator and rotor combination installation are in the inside of casing, and the stator includes by a plurality of stator coil arrangement and is connected to form three -phase stator winding, and three -phase stator winding forms complete and continuous annular structure through vacuum pressure impregnation fluorinated epoxy resin, and stator coil is all completely covered and solidified as an organic whole by epoxy resin, and the clearance between stator coil and stator slot inside are all filled by epoxy resin, form continuous and dense protective layer, thereby, the insulation of coil, mechanical strength and environmental resistance have been improved, through material improvement and protection technology integration, the corrosion resistance of coil in the environment has been improved significantly, the vibration problem caused by corrosion has been solved, the unit operation reliability has been improved, and the equipment service life has been prolonged.

Description

Technical Field

[0001] This utility model relates to the field of heat pump equipment technology, and in particular to a refrigerant-resistant magnetic levitation centrifugal heat pump. Background Technology

[0002] Magnetic levitation centrifugal heat pump units have become a focus of research in recent years, with their core advantage stemming from the use of magnetic levitation bearing technology in the centrifugal compressor. This technology uses an electromagnetic field to levitate the rotor in mid-air, eliminating frictional losses caused by mechanical bearings and achieving oil-free operation and near-zero wear.

[0003] During the operation of a heat pump unit, refrigerant may seep into the stator through tiny gaps, undergoing a slow chemical reaction with the coil insulation material and conductive metal. Under extremely strong electromagnetic fields, high-frequency vibrations, and high-temperature, high-pressure conditions, this corrosion process is significantly accelerated, especially for refrigerants such as R123, whose thermodynamic properties are suitable for centrifugal compressors; their corrosiveness poses a more severe challenge to the stator.

[0004] The corrosive effects of refrigerant are often not uniform, and this selective corrosion leads to an imbalance in the electrical parameters of the coil windings. When current flows through coils with inconsistent performance, the resulting electromagnetic force will no longer be balanced, and the rotor will be subjected to periodically varying eccentric forces, thus inducing vibration. This affects the stability and reliability of the unit's operation, resulting in a shortened service life and increased maintenance costs. Utility Model Content

[0005] The technical problem this invention aims to solve is: addressing the issue that in existing magnetic levitation centrifugal heat pumps using refrigerant, the stator coils are susceptible to corrosion, leading to increased vibration. This invention provides a refrigerant-resistant magnetic levitation centrifugal heat pump that, through material improvement and integrated protection technology, significantly enhances the coils' resistance to corrosion in the environment, solves the vibration problem caused by corrosion, improves the reliability of unit operation, and extends the service life of the equipment.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a refrigerant-resistant magnetic levitation centrifugal heat pump, including a magnetic levitation compressor, the magnetic levitation compressor including a housing, a stator, and a high-precision rotor; the stator and rotor are assembled and installed inside the housing, the rotor is fitted with two radial suspension bearings, and the stator is located between the two radial suspension bearings, the radial suspension bearings are fixedly installed inside the housing; a cable box is fixedly installed on one side of the housing, the three-phase copper busbar is arranged in the cable box, and the three-phase lines of the stator are connected to the three-phase copper busbar; The stator includes a three-phase stator winding formed by arranging and connecting multiple stator coils. The three-phase stator winding is formed into a complete and continuous ring structure using a vacuum pressure impregnation process with a low-viscosity impregnating varnish, such as fluorinated epoxy resin. The stator coils are made of polytetrafluoroethylene (PTFE) or polyetheretherketone (PEEK) as the base material, with the addition of nano-ceramic fillers to form a composite insulation layer with a temperature resistance rating of H. This improves the insulation, mechanical strength and environmental resistance of the coils.

[0007] Furthermore, the fluorinated epoxy resin accounts for 4%-7% of the rotor mass; the nano-ceramic filler of the insulating layer is alumina or silicon carbide, and the nano-ceramic filler accounts for 10%-20% of the mass; the total thickness of the multilayer protective coating is 80-100μm, and the thickness of the ETFE coating is 40-60μm.

[0008] Furthermore, the stator coil employs a multi-layer protective coating, which consists of an electrophoretic epoxy primer layer, an ETFE coating, and a ceramic film formed by vapor deposition from the inside out; thereby improving the overall resistance to refrigerant immersion.

[0009] Furthermore, the housing includes an outer layer and an inner layer. The outer layer has a placement cavity extending through both ends. The inner layer is fitted into the placement cavity via a transition fit, forming a sandwich between the placement cavity and the inner layer. A spiral groove is formed on the inner wall of the outer layer. An air inlet is formed on one side of the housing, with one end communicating with the spiral groove. An exhaust port is formed on the other side of the housing, with one end communicating with the sandwich. The exhaust port is equipped with a one-way pressure relief valve. Thus, dry nitrogen gas is introduced into the sandwich through the air inlet to maintain a slight positive pressure, preventing refrigerant from seeping into the sandwich and corroding the stator coil.

[0010] Furthermore, the stator is sleeved on the outside of the inner layer, and an outer spiral mounting component is sleeved on the outside of the stator. The outer spiral mounting component is connected to the spiral groove; thereby, the position of the stator is limited by the spiral groove.

[0011] Furthermore, the radial suspension bearing is fixedly installed inside the inner layer, the rotor is suspended inside the inner layer, the axis of the rotor and the axis of the inner layer are on the same straight line, and the rotor penetrates through the inner layer.

[0012] Furthermore, the inner wall of the outer layer is provided with a slot, one end of which is connected to the placement cavity and the other end of which is connected to the wiring box; thereby, the three-phase wires of the stator coil are connected to the three-phase copper busbars in the wiring box through the slot.

[0013] Furthermore, a sealing ring assembly is provided between the outer side of the inner layer and the outer layer. The sealing ring assembly is a composite sealing ring made of metal-ceramic material combined with a fluororubber O-ring; thereby ensuring long-term sealing reliability.

[0014] Furthermore, the specific steps of the vacuum pressure impregnation process are as follows: S1. Binding and Fixing: Before impregnation with epoxy resin, insulating tape (such as polyester film tape) or binding tape must be used to fix the enameled wire to prevent the coil from loosening or shifting. The gaps should be controlled during binding to facilitate uniform penetration of epoxy resin. The tape should be selected to be heat-resistant and compatible with low-viscosity epoxy resin to avoid detachment or contamination of the enameled wire surface after curing. S2. Pre-treatment: After binding, the coils must be thoroughly cleaned to remove oil and dust. If necessary, they can be blown out with compressed air. Then, a pre-baking treatment is carried out, usually with the temperature controlled at 100-120℃ for 2-4 hours, to remove moisture and volatiles and prevent bubbles from forming during impregnation. S3, Vacuum Impregnation: The coil is placed in a vacuum tank and the pressure is reduced to below 0.1 kPa to remove air and tiny air bubbles, ensuring that the resin completely fills the winding gaps; then, the two-component epoxy resin is mixed in proportion and injected, and the negative pressure is used to make the resin penetrate into the tiny gaps inside the coil, including the gaps formed by the tape binding; after impregnation, pressure is applied to promote a tight bond between the resin and the coil and reduce the risk of delamination.

[0015] S4. Curing and post-treatment: After curing at room temperature for more than 24 hours, check the integrity of the adhesive layer. If necessary, remove small air bubbles with a vacuum degassing machine or correct local defects with mechanical polishing.

[0016] Therefore, the tape binding and vacuum impregnation technology can significantly improve the reliability and lifespan of motor coils. After curing, the bonding strength between the coil and the iron core is improved, and the vibration resistance is significantly improved.

[0017] The beneficial effects of this utility model are that the refrigerant-resistant magnetic levitation centrifugal heat pump of this utility model adopts a vacuum pressure impregnation process to completely fill the coil gap with epoxy resin, combined with binding and fixing technology, and an integrated stator structure, which effectively avoids cracks caused by refrigerant erosion, avoids surface contamination of enameled wire, reduces the risk of delamination, and enhances the overall chemical corrosion resistance of the coil.

[0018] This utility model of a refrigerant-resistant magnetic levitation centrifugal heat pump utilizes a stator coil with a composite insulation layer formed by PTFE / PEEK-based composite material and nano-ceramic filler, achieving a temperature resistance rating of H. Furthermore, the use of multi-layer protective coatings, including an electrophoretic epoxy primer composite with ETFE and a vapor-deposited ceramic film, enhances the coil's resistance to R123 immersion, effectively preventing refrigerant penetration.

[0019] This utility model of a refrigerant-resistant magnetic levitation centrifugal heat pump uses a double-layer design inside and outside the shell, combined with a dry nitrogen micro-positive pressure protection system, to prevent refrigerant from seeping into the interlayer and corroding the stator coil. At the same time, the limiting structure of the spiral groove and the outer spiral mounting component reduces the vibration caused by rotor eccentricity. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the refrigerant-resistant magnetic levitation centrifugal heat pump of this utility model.

[0022] Figure 2 yes Figure 1 A schematic diagram of the structure of a magnetic levitation compressor.

[0023] Figure 3 yes Figure 2 A schematic diagram showing the positional relationship between the outer and middle layers and the cable box.

[0024] Figure 4 yes Figure 3 A front view of the overall structure.

[0025] Figure 5 yes Figure 4 A schematic cross-sectional view of section A.

[0026] Figure 6 This is a schematic diagram showing the positional relationship between the outer and inner layers.

[0027] Figure 7 This is a cross-sectional schematic diagram of the inner layer.

[0028] In the diagram: 1. Magnetic levitation compressor; 11. Outer body; 111. Placement cavity; 112. Slot; 113. Spiral groove; 114-1. Air inlet; 114-2. Air outlet; 12. Inner body; 121. Radial suspension bearing; 122. Rotor; 13. Three-phase stator winding; 14. Cable box. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0030] like Figures 1-7As shown, a refrigerant-resistant magnetic levitation centrifugal heat pump includes a magnetic levitation compressor 1. The magnetic levitation compressor 1 includes a housing, a stator, and a high-precision rotor 122. The stator and rotor 122 are assembled and installed inside the housing. Two radial suspension bearings 121 are sleeved on the rotor 122, and the stator is located between the two radial suspension bearings 121. The radial suspension bearings 121 are fixedly installed inside the housing. A cable box 14 is fixedly installed on one side of the housing. Three-phase copper busbars are arranged in the cable box 14. The three-phase lines of the stator are connected to the three-phase copper busbars. The stator includes a three-phase stator winding 13 formed by arranging and connecting multiple stator coils.

[0031] Among them, the three-phase stator winding 13 adopts vacuum pressure impregnation. The specific preparation process is as follows: the coil substrate is made of polytetrafluoroethylene (PTFE) as the matrix, with 15% nano alumina ceramic filler added. The composite insulation layer is formed by hot pressing and the thickness is controlled at 0.5mm. Then, the coil is fixed by cross binding with high temperature resistant polyester film tape, with a gap width ≤0.2mm. After pre-baking treatment at 115℃ for 3 hours, it is impregnated with fluorinated epoxy resin under vacuum of 0.1kPa and pressurized to 0.4MPa for 30 minutes. Finally, after curing at room temperature, the surface is coated with an electrophoretic epoxy primer with a thickness of 20μm, an ETFE coating with a thickness of 50μm, and a vapor-deposited zirconia ceramic film with a thickness of 10μm. Thus, the three-phase stator winding 13 forms a complete and continuous annular structure by impregnating fluorinated epoxy resin under vacuum pressure. The stator coils are completely covered and cured into one piece by epoxy resin. The gaps between the stator coils and the interior of the stator slots are filled with epoxy resin to form a continuous and dense protective layer. This ensures that the three-phase stator winding 13 does not experience coating peeling after being immersed in R123 refrigerant.

[0032] Furthermore, to enhance sealing, the housing of the magnetic levitation compressor 1 is also optimized in this invention. (See reference...) Figures 3-7 The housing includes an outer layer 11 made of 316L stainless steel and an inner layer 12 made of anodized aluminum alloy. The outer layer 11 has a placement cavity 111 extending through both ends. The inner layer 12 is fitted into the placement cavity 111 via a transition fit, forming a sandwich between the placement cavity 111 and the inner layer 12. The inner wall of the outer layer 11 has a spiral groove 113. One side of the housing has an air inlet 114-1, one end of which communicates with the spiral groove 113. The other side of the housing has an exhaust port 114-2, one end of which communicates with the sandwich. The exhaust port 114-2 is equipped with a one-way pressure relief valve. Dry nitrogen is introduced into this sandwich, and the spiral groove 13 guides the nitrogen to distribute evenly, thus preventing refrigerant from seeping into the sandwich and corroding the stator coils of the three-phase stator winding 13. Additionally, the introduced nitrogen can cool the housing, reducing the impact of uneven temperature distribution at the stator.

[0033] Wherein: the stator is sleeved on the outside of the inner layer 12, and an outer spiral mounting component is sleeved on the outside of the stator. The outer spiral mounting component is connected to the spiral groove 113 (see reference). Figure 6 Thus, the position of the stator is limited by the spiral groove 113. (See reference...) Figure 7 A radial suspension bearing 121 is fixedly installed inside the inner layer 12, and a rotor 122 is suspended inside the inner layer 12. The axis of the rotor 122 is on the same straight line as the axis of the inner layer 12, and the rotor 122 penetrates through the inner layer 12. (Refer to...) Figure 5 The inner wall of the outer body 11 has a slot 112. One end of the slot 112 is connected to the placement cavity 111, and the other end of the slot 112 is connected to the wiring box 14. Thus, the three-phase wires of the stator coil are connected to the three-phase copper busbar through the slot 112.

[0034] A metal-ceramic composite sealing ring is provided between the outer layer 11 and the inner layer 12, wherein a fluororubber O-ring is embedded in the sealing ring, thereby improving the sealing degree and reducing the probability of refrigerant entering the interlayer and causing corrosion.

[0035] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Images