A spray cooling motor for semi-hermetic centrifugal compressor and waste heat recovery system

Abstract

This invention relates to the field of motor cooling technology, specifically disclosing a spray-cooled motor for a semi-hermetic centrifugal compressor and a waste heat recovery system. The spray-cooled motor for the semi-hermetic centrifugal compressor has several heat dissipation channels on its stator assembly connecting both ends. A baffle is installed inside the motor housing, dividing the inner cavity of the motor housing into a cooling chamber containing the rotor assembly and stator assembly. The rotating shaft passes through the baffle. A first spray pipe and a second spray pipe are provided on both axial sides of the stator assembly, each equipped with several nozzles. This spray-cooled motor for the semi-hermetic centrifugal compressor makes the temperature field in both the stator assembly and rotor assembly axial directions more even, improving the motor's electromechanical energy conversion efficiency. The waste heat recovery system uses the heat generated by the motor as a low-grade heat source for a heat pump system, transferring the heat generated by the motor to the condenser side for output, thus realizing waste heat utilization.

Description

Technical Field

[0001] This invention relates to the field of energy-saving electric motors, and more particularly to the field of motor cooling technology, specifically to a spray-cooled motor and waste heat recovery system for a semi-hermetic centrifugal compressor. Background Technology

[0002] In a semi-hermetic centrifugal compressor, the motor rotor and compressor impeller are directly connected as one unit, and the motor and compressor are enclosed in the same housing. This eliminates the need for a gear transmission device, which helps reduce the failure rate. However, since the motor is enclosed in the housing, the heat generated by the motor stator, rotor, and coils during operation is difficult to dissipate directly to the external environment through convection and thermal radiation. If heat dissipation is not timely and effective, it will lead to increased motor temperature, decreased rotor magnetism, reduced compression efficiency, further increase in iron and copper losses, and increased energy loss.

[0003] Water-cooled jackets consist of circulating water channels on the motor stator, which remove heat through water circulation. However, they can only cool the stator and cannot effectively cool heat-generating parts such as the motor rotor and coil windings. This results in a large internal temperature gradient within the motor and fails to solve the problem of localized overheating.

[0004] Lubricating oil cooling involves circulating lubricating oil to carry away heat and dissipate it through an external cooler. However, lubricating oil is prone to aging and deterioration at high temperatures, which affects the cooling effect and results in poor cooling of the motor rotor and coil windings. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the existing defects and provide a spray-cooled motor and waste heat recovery system for a semi-hermetic centrifugal compressor. The spray-cooled motor for the semi-hermetic centrifugal compressor has a good cooling effect on the stator assembly and rotor assembly. The temperature fields in the axial direction of the stator assembly and the rotor assembly tend to be flat and the temperature difference in various places is significantly reduced, avoiding local overheating, improving the electromechanical energy conversion efficiency of the motor, and increasing the upper limit of the continuous output power of the motor. The waste heat recovery system uses the heat generated by the motor as a low-grade heat source for the heat pump system. Without increasing the load of the semi-hermetic centrifugal compressor, the heat generated by the motor is transferred to the condenser side for output, realizing the utilization of waste heat.

[0006] The technical solution adopted by this invention to solve its technical problem includes: On one hand, a spray-cooled motor for a semi-hermetic centrifugal compressor is provided, including a motor housing, a stator assembly and a rotor assembly inside the motor housing, the rotor assembly including a shaft and a rotor body.

[0007] The stator assembly has several heat dissipation channels connecting the two ends of the stator assembly.

[0008] A baffle is installed inside the motor housing, which divides the inner cavity of the motor housing into a cooling chamber containing the rotor assembly and stator assembly. The shaft passes through the baffle.

[0009] The stator assembly has a first spray pipe and a second spray pipe on both sides of the axial direction. Each of the first spray pipe and the second spray pipe is equipped with several nozzles. The first spray pipe is equipped with a second solenoid valve, and the second spray pipe is equipped with a first solenoid valve.

[0010] A housing, blades, and a sliding frame are sequentially arranged on the rotating shaft along the direction away from the rotor body. The sliding frame can slide along the axial direction of the rotating shaft. An air guide annular groove is opened on the outer periphery of the housing.

[0011] The rotating shaft has an air passage chamber inside, and a first through hole and a second through hole are opened on the rotating shaft to connect the air passage chamber. The first through hole is connected to the inner cavity of the housing, and the blade is located between the first through hole and the second through hole.

[0012] A power component is installed on the rotating shaft or the motor housing, which can drive the sliding frame to move along the axial direction of the rotating shaft.

[0013] When the round tube rests against the stator assembly, the sliding bracket completely blocks the second through hole, and the first solenoid valve closes and the second solenoid valve opens.

[0014] When the round tube abuts against the baffle or motor housing, the sliding bracket and the second through hole are misaligned, and the first solenoid valve opens and the second solenoid valve closes.

[0015] As a preferred embodiment of the present invention, the heat dissipation channel on the stator assembly includes several accommodating spaces, and any two adjacent accommodating spaces are staggered in the circumferential direction of the stator assembly and partially connected in the axial direction.

[0016] As a preferred embodiment of the present invention, an annular plate is provided on the stator assembly near the housing. The outer diameter of the annular plate is smaller than the inner diameter of the circular tube, and the inner diameter of the annular plate is larger than the outer diameter of the housing and the inner diameter of the stator assembly.

[0017] As a preferred embodiment of the present invention, the motor housing has an opening that communicates with the cooling cavity, and the opening is connected to one end of the first connecting pipe.

[0018] As a preferred embodiment of the present invention, both the first spray pipe and the second spray pipe are arc-shaped.

[0019] As a preferred embodiment of the present invention, the sliding frame, the connector, and the round tube are integrally formed.

[0020] In a preferred embodiment of the present invention, the power component is an electromagnet and the sliding frame is a magnetically attached component.

[0021] As a preferred embodiment of the present invention, an elastic element is installed on the connector, and the elastic element abuts against the baffle or the motor housing.

[0022] As a preferred embodiment of the present invention, the outer periphery of the circular tube is provided with an oil-absorbing felt.

[0023] On the other hand, a waste heat recovery system is also provided, which is used in conjunction with the aforementioned spray cooling motor for a semi-hermetic centrifugal compressor. The motor housing has an opening that connects to the cooling chamber. The opening is connected to one end of a first connecting pipe. The other end of the first connecting pipe is connected to the first inlet of an electromagnetic proportional valve. The other inlet of the electromagnetic proportional valve is connected to one end of a fifth connecting pipe. The outlet of the electromagnetic proportional valve is connected to one end of a manifold.

[0024] The second solenoid valve is connected to the first connection port of the three-way pipe, the second connection port of the three-way pipe is connected to the first solenoid valve through the second connection pipe, and the third connection port of the three-way pipe is connected to one end of the fourth connection pipe.

[0025] Compared with the prior art, the beneficial effects of the present invention are: 1. The spray-cooled motor for the semi-hermetic centrifugal compressor of this invention has the following advantages: First, the flow direction of the atomized coolant in the heat dissipation channel of the stator assembly continuously changes, making the temperature field in both the axial direction of the stator assembly and the axial direction of the rotor assembly more even and significantly reducing the temperature difference at various points, thus avoiding local overheating. The stator assembly can withstand a higher average electrical load, thereby increasing the upper limit of the motor's continuous output power. When the motor is running under high load, the atomized coolant and the outer surface of the stator assembly are in full contact, enabling the coil windings on the stator assembly to achieve balanced cooling, fundamentally reducing copper loss and improving the electromechanical energy conversion efficiency of the motor. Second, the concentration of coolant droplets in the gas between the stator assembly and the rotor assembly is lower than that in the gas within the heat dissipation channel of the stator assembly. The liquid film generated on the inner wall of the stator assembly due to the spiral flow and centrifugal force of the atomized coolant is thin, avoiding the formation of randomly distributed liquid blocks or liquid rings between the stator assembly and the rotor assembly. The mass distribution of the rotor assembly is not affected by the coolant, thus stabilizing the dynamic balance of the rotor assembly.

[0026] 2. In the example of the spray-cooled motor for the semi-hermetic centrifugal compressor of the present invention, the heat dissipation channels on the stator assembly are arranged in a stepped staggered manner: on the one hand, the atomized coolant flows through a longer path in the heat dissipation channel, and has a larger contact area with the heat-generating parts, which can absorb more heat and increase the effective heat dissipation area of ​​the stator assembly; on the other hand, the atomized coolant passes through multiple eddies during its flow through the heat dissipation channel, so that the large droplets in the atomized coolant preferentially contact the inner wall of the heat dissipation channel, avoiding the formation of randomly distributed liquid blocks or liquid rings between the stator assembly and the rotor assembly.

[0027] 3. The waste heat recovery system of this invention uses the heat generated by the motor as the low-grade heat source of the heat pump system. Without increasing the load on the semi-hermetic centrifugal compressor, this heat is transferred to the condenser side for output through the first connecting pipe and the electromagnetic proportional valve. This not only improves the heat dissipation efficiency of the motor, but also turns the energy loss into a valuable resource, further improving the overall performance coefficient of the heat pump. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention from one perspective; Figure 2 for Figure 1 A partial sectional view of the structure; Figure 3 for Figure 1 Another perspective structural diagram; Figure 4 This is a schematic diagram of the structure of the present invention installed inside the motor housing; Figure 5 This is a partial cross-sectional view of the structure of the present invention in one working state; Figure 6 for Figure 5 Another perspective structural diagram; Figure 7 This is a partial cross-sectional view of another working state of the present invention; Figure 8 for Figure 7 An enlarged schematic diagram of the structure at point A.

[0029] In the diagram: 1. Shaft, 2. Power assembly, 3. Sliding frame, 4. Circular tube, 5. Stator assembly, 6. Blade, 7. Housing, 8. Air guide annular groove, 9. Annular plate, 10. First through hole, 11. Second through hole, 12. Elastic element, 13. Connector, 14. First connecting pipe, 15. First solenoid valve, 16. Second connecting pipe, 17. Rotor assembly, 18. Second solenoid valve, 19. Three-way pipe, 20. Electromagnetic proportional valve, 21. Manifold, 22. Fourth connecting pipe, 23. Motor housing, 24. First spray pipe, 25. Second spray pipe, 26. Baffle, 27. Fifth connecting pipe. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] Example 1: Please see Figures 1-8This embodiment discloses a spray-cooled motor for a semi-hermetic centrifugal compressor, including a motor housing 23, a stator assembly 5 and a rotor assembly 17 inside the motor housing 23, and the rotor assembly 17 includes a rotating shaft 1 and a rotor body.

[0032] The stator assembly 5 is provided with several heat dissipation channels that connect the two ends of the stator assembly 5.

[0033] A baffle 26 is installed inside the motor housing 23. The baffle 26 divides the inner cavity of the motor housing 23 into a closed cooling cavity containing the rotor assembly 17 and the stator assembly 5. The rotating shaft 1 passes through the baffle 26, and the baffle 26 does not affect the rotation of the rotating shaft 1.

[0034] The stator assembly 5 has a first spray pipe 24 and a second spray pipe 25 on both sides of the axis. Several nozzles are installed on the first spray pipe 24 and the second spray pipe 25. The motor cover 23 has a first mounting port and a second mounting port that communicate with the cooling cavity. The first mounting port communicates with the inner cavity of the first spray pipe 24. A second solenoid valve 18 is installed on the first mounting port. The second mounting port communicates with the inner cavity of the second spray pipe 25. A first solenoid valve 15 is installed on the second mounting port.

[0035] A hollow annular housing 7, at least two blades 6, and a sliding frame 3 are sequentially arranged on the shaft 1 along the direction away from the rotor body. The blades 6 are fixedly installed on the shaft 1 and are located inside the circular tube 4. The sliding frame 3 can slide along the axial direction of the shaft 1. An annular gas guide groove 8 is provided on the outer periphery of the housing 7. When gas is continuously injected into the housing 7, the gas in the housing 7 is ejected through the annular gas guide groove 8 to form a conical airflow. The conical airflow enters the gap between the stator assembly 5 and the rotor assembly 17.

[0036] The rotating shaft 1 has an air passage chamber inside. The rotating shaft 1 has a first through hole 10 and a second through hole 11 connected to the air passage chamber. The housing 7 has a connecting hole at the position corresponding to the first through hole 10. The air passage chamber is connected to the inner cavity of the housing 7 through the first through hole 10 and the connecting hole. The blade 6 is located between the first through hole 10 and the second through hole 11.

[0037] A power component 2, which can drive the sliding frame 3 to move axially along the shaft 1, is installed on the shaft 1 or the motor housing 23.

[0038] The rotating shaft 1 drives the blades 6 to rotate, and the rotating blades 6 generate airflow away from the stator assembly 5 in the circular tube 4. When the circular tube 4 is against the stator assembly 5, the sliding frame 3 completely blocks the second through hole 11, the first solenoid valve 15 is closed and the second solenoid valve 18 is open. When the circular tube 4 is against the baffle 26 or the motor housing 23, the circular tube 4 and the stator assembly 5 are not in contact, the sliding frame 3 and the second through hole 11 are offset, the first solenoid valve 15 is open and the second solenoid valve 18 is closed.

[0039] Furthermore, the sliding frame 3, the connector 13, and the round tube 4 are integrally formed.

[0040] Preferably, the first solenoid valve 15 and the second solenoid valve 18 are electrically connected to an external time relay.

[0041] The working process and principle of this embodiment are as follows: Both the first solenoid valve 15 and the second solenoid valve 18 are connected to an external coolant delivery pipeline, through which pressurized liquid coolant flows.

[0042] When the coil windings on the stator assembly 5 are energized, an alternating magnetic field is generated, causing the rotor assembly 17 to rotate. The rotating shaft 1 drives the blades 6 to rotate, and the rotating blades 6 generate an airflow in the circular tube 4 that flows away from the stator assembly 5.

[0043] When the circular tube 4 abuts against the stator assembly 5, the sliding frame 3 completely blocks the second through hole 11. The rotating blades 6 cause the gas in the cooling chamber to circulate. The gas flow direction is the space between the inner cavity of the circular tube 4, the outer periphery of the circular tube 4 and the inner wall of the motor housing 23, the heat dissipation channel on the stator assembly 5, the gap between the stator assembly 5 and the rotor assembly 17, and then back to the inner cavity of the circular tube 4. The external time relay closes the first solenoid valve 15 and opens the second solenoid valve 18. The nozzle on the first spray pipe 24 sprays atomized coolant. The atomized coolant first flows through the heat dissipation channel on the stator assembly 5, and then flows through the gap between the stator assembly 5 and the rotor assembly 17.

[0044] When the circular tube 4 abuts against the baffle 26 or the motor housing 23, the sliding frame 3 and the second through hole 11 are misaligned, and the circular tube 4 and the stator assembly 5 do not contact each other. The rotating blades 6 cause the gas in the cooling chamber to circulate. The gas flow direction is: the inner cavity of the circular tube 4, the second through hole 11, the air passage in the rotating shaft 1, the first through hole 10, the inner cavity of the housing 7, the air guide annular groove 8, the gap between the stator assembly 5 and the rotor assembly 17, the heat dissipation channel on the stator assembly 5, the space between the circular tube 4 and the stator assembly 5, and then back to the inner cavity of the circular tube 4. The external time relay causes the first solenoid valve 15 to open and the second solenoid valve 18 to close. The nozzles on the second spray pipe 25 spray atomized coolant. The atomized coolant first flows through the heat dissipation channel on the stator assembly 5, and then flows through the gap between the stator assembly 5 and the rotor assembly 17.

[0045] The flow direction of the atomized coolant in the heat dissipation channel of stator assembly 5 is constantly changing, which makes the temperature field in both the axial direction of stator assembly 5 and rotor assembly 17 more gradual and significantly reduces the temperature difference in various places. This avoids local overheating, and stator assembly 5 can withstand a higher average electrical load, thereby increasing the upper limit of the motor's continuous output power. This allows motors of the same specifications to output greater power. It also makes the working temperature of the insulation material in various parts of stator assembly 5 similar, avoiding coil winding insulation failure due to local overheating, extending the service life of motor insulation material, and improving the operational reliability of the motor.

[0046] It reduces the thermal deformation stress caused by thermal imbalance in stator assembly 5 and rotor assembly 17, ensuring the structural integrity and installation accuracy of stator assembly 5 and rotor assembly 17, while suppressing vibration and noise caused by unbalanced thermal deformation stress.

[0047] The concentration of coolant droplets in the gas between stator assembly 5 and rotor assembly 17 is less than the concentration of coolant droplets in the gas in the heat dissipation channel of stator assembly 5. The liquid film generated by the spiral flow and centrifugal flow of atomized coolant on the inner wall of stator assembly 5 is thin, which avoids the formation of randomly distributed liquid blocks or liquid rings between stator assembly 5 and rotor assembly 17. The mass distribution of rotor assembly 17 is not affected by the coolant, thus stabilizing the dynamic balance of rotor assembly 17.

[0048] Furthermore, the pressurized liquid coolant flowing into the first solenoid valve 15 and the second solenoid valve 18 is drawn out from the bottom of the heat pump condenser that is matched with the semi-hermetic centrifugal compressor. The gaseous coolant in the cooling chamber is compressed by the semi-hermetic centrifugal compressor and then transported to the condenser that is matched with the semi-hermetic centrifugal compressor through the oil-gas separator.

[0049] Preferably, the power component 2 is an electromagnet, the sliding frame 3 is a magnetic coupling component, and an elastic element 12 is installed on the connecting component 13. The elastic element 12 abuts against the baffle 26 or the motor housing 23. The elastic element 12 is an elastic sheet or an elastic block. The electromagnet is electrically connected to an external time relay: When the electromagnet is energized, the electromagnet causes the magnetic coupling component to drive the round tube 4 to move along the axial direction of the rotating shaft 1 through the connecting component 13. The elastic element 12 deforms and its elastic potential energy increases, and the round tube 4 does not contact the stator assembly 5. When the electromagnet is de-energized, the elastic element 12 causes the magnetic coupling component to drive the round tube 4 to move in the opposite direction along the axial direction of the rotating shaft 1 through the connecting component 13. The elastic potential energy of the elastic element 12 decreases, and the round tube 4 abuts against the stator assembly 5. The energizing time of the electromagnet is 2.0s-20.0s, and the energizing working cycle of the electromagnet is the same as the energizing working cycle of the first solenoid valve 15.

[0050] Furthermore, both the first spray pipe 24 and the second spray pipe 25 are arc-shaped, or both the first spray pipe 24 and the second spray pipe 25 are annular, so that the atomized coolant is evenly distributed in the circumferential direction of the stator assembly 5.

[0051] Furthermore, the sliding frame 3 and the rotating shaft 1 can rotate relative to each other. A guide rail frame is installed on the motor housing 23, and a sliding slider is installed on the guide rail frame. The slider is fixed on the round tube 4, and the guide rail frame and the slider cooperate to allow the round tube 4 to move axially.

[0052] Furthermore, both the first solenoid valve 15 and the second solenoid valve 18 are electronic expansion valves commonly found in existing heat pumps or air conditioners.

[0053] Example 2: like Figure 1 , Figure 2 , Figures 5-7 As shown, this embodiment discloses a spray-cooled motor for a semi-hermetic centrifugal compressor. Its structure is roughly the same as that of Embodiment 1. The difference is that the heat dissipation channel on the stator assembly 5 in this embodiment includes several receiving spaces. Any two adjacent receiving spaces are staggered upward around the stator assembly 5 and partially connected along the axial direction.

[0054] The working process and principle of this embodiment are as follows: The stator assembly 5 includes several stator core laminations stacked sequentially along the axial direction. Each stator core lamination includes several completely overlapping stator cores. Each stator core lamination has multiple receiving spaces spaced apart along its circumference. The receiving spaces on adjacent laminations are partially staggered in the circumference, so that the heat dissipation channel formed by the stacked laminations is arranged in a stepped staggered manner. The atomized coolant flows through a longer path in the heat dissipation channel, has a larger contact area with the heat-generating parts, and can absorb more heat, thereby increasing the effective heat dissipation area of ​​the stator assembly 5.

[0055] The heat dissipation channels on the stator assembly 5 are arranged in a stepped staggered manner. The atomized coolant passes through multiple eddies during its flow through the heat dissipation channels, which allows large droplets in the atomized coolant to preferentially contact the heat dissipation channels, thus avoiding the formation of randomly distributed liquid blocks or liquid rings between the stator assembly 5 and the rotor assembly 17.

[0056] Example 3: like Figure 2 , Figure 3 As shown, this embodiment discloses a spray-cooled motor for a semi-hermetic centrifugal compressor. Its structure is roughly the same as that of Embodiment 1. The difference is that in this embodiment, an annular plate 9 is installed near the housing 7 of the stator assembly 5. The outer diameter of the annular plate 9 is smaller than the inner diameter of the circular tube 4, and the inner diameter of the annular plate 9 is larger than the outer diameter of the housing 7 and the inner diameter of the stator assembly 5.

[0057] The working process and principle of this embodiment are as follows: The annular plate 9 ensures that the conical airflow ejected from the annular air guide groove 8 completely enters the gap between the stator assembly 5 and the rotor assembly 17, thereby improving the reliability of the spray-cooled motor used in this semi-hermetic centrifugal compressor.

[0058] Example 4: like Figures 4-7 As shown, this embodiment discloses a spray-cooled motor for a semi-hermetic centrifugal compressor. Its structure is roughly the same as that of Embodiment 1. The difference is that the motor housing 23 in this embodiment has an opening that connects to the cooling cavity, and the opening is connected to one end of the first connecting pipe 14.

[0059] Furthermore, the gas inside the cooling chamber is a gaseous coolant.

[0060] The working process and principle of this embodiment are as follows: An external compressor or a semi-hermetic centrifugal compressor that is compatible with this cooling system can extract gaseous coolant from the cooling chamber of the motor housing 23 through the first connecting pipe 14.

[0061] Example 5: like Figure 2 As shown, this embodiment discloses a spray-cooled motor for a semi-hermetic centrifugal compressor. Its structure is roughly the same as that of Embodiment 1. The difference is that in this embodiment, the outer periphery of the circular tube 4 is provided with an oil-absorbing felt, on which lubricating oil is absorbed.

[0062] The working process and principle of this embodiment are as follows: During the operation of the stator assembly 5 and the rotor assembly 17, the debris generated is carried by the airflow to the oil-absorbing felt and adheres to the oil-absorbing felt, reducing the damage of the debris to the stator assembly 5 and the rotor assembly 17.

[0063] Example 6: like Figures 4-7 As shown, this embodiment discloses a waste heat recovery system, which is used in conjunction with the spray cooling motor of the semi-hermetic centrifugal compressor in Embodiment 1. In this embodiment, the motor housing 23 has an opening that connects to the cooling chamber. The opening is connected to one end of the first connecting pipe 14, and the other end of the first connecting pipe 14 is connected to the first inlet of the electromagnetic proportional valve 20. The other inlet of the electromagnetic proportional valve 20 is connected to one end of the fifth connecting pipe 27, and the outlet of the electromagnetic proportional valve 20 is connected to one end of the manifold 21.

[0064] The second solenoid valve 18 is connected to the first connection port of the three-way pipe 19, the second connection port of the three-way pipe 19 is connected to the first solenoid valve 15 through the second connection pipe 16, and the third connection port of the three-way pipe 19 is connected to one end of the fourth connection pipe 22.

[0065] The working process and principle of this embodiment are as follows: This waste heat recovery system and the semi-hermetic centrifugal compressor are used in conjunction with a spray-cooled motor for use with a heat pump.

[0066] Pressurized liquid coolant in the first solenoid valve 15 and the second solenoid valve 18 flows into the heat pump condenser, which is matched with the semi-hermetic centrifugal compressor, from the bottom through the fourth connecting pipe 22, the three-way pipe 19, and the second connecting pipe 16. Gaseous coolant in the cooling chamber flows through the first connecting pipe 14, the electromagnetic proportional valve 20, and the external gas-liquid separator, and is then compressed by the semi-hermetic centrifugal compressor and finally delivered to the condenser matched with the semi-hermetic centrifugal compressor. Gaseous coolant in the heat pump evaporator flows through the fifth connecting pipe 27, the electromagnetic proportional valve 20, and the external gas-liquid separator, and is then compressed by the semi-hermetic centrifugal compressor and finally delivered to the condenser matched with the semi-hermetic centrifugal compressor.

[0067] This waste heat recovery system uses the heat generated by the motor as a low-grade heat source for the heat pump system. Without increasing the load on the semi-hermetic centrifugal compressor, this heat is transferred to the condenser side for output through the first connecting pipe 14 and the electromagnetic proportional valve 20. This not only improves the heat dissipation efficiency of the motor, but also turns the energy loss into a valuable resource, further improving the overall performance coefficient of the heat pump.

[0068] When the ambient temperature is too low, the operator controls the electromagnetic proportional valve 20 through the controller program, which speeds up the extraction of gaseous coolant from the cooling chamber, thereby reducing the air pressure in the cooling chamber, lowering the boiling point of the coolant, and reducing the amount of heat absorbed by the coolant, making it easier for the lubricating oil in the motor to quickly reach the operating temperature.

[0069] When the ambient temperature is too high, the operator controls the electromagnetic proportional valve 20 through the controller program, which slows down the rate at which the gaseous coolant is drawn from the cooling chamber, thereby increasing the gas pressure in the cooling chamber, raising the boiling point of the coolant, and allowing the coolant to absorb more heat, thus preventing the motor from overheating.

[0070] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A spray-cooled motor for a semi-hermetic centrifugal compressor, comprising a motor housing (23), a stator assembly (5) and a rotor assembly (17) within the motor housing (23), the rotor assembly (17) comprising a shaft (1) and a rotor body, characterized in that: The stator assembly (5) is provided with several heat dissipation channels connecting the two ends of the stator assembly (5); A baffle (26) is installed inside the motor housing (23). The baffle (26) divides the inner cavity of the motor housing (23) into a cooling cavity containing a rotor assembly (17) and a stator assembly (5). The rotating shaft (1) passes through the baffle (26). The stator assembly (5) has a first spray pipe (24) and a second spray pipe (25) on both sides of the axial direction. Several nozzles are installed on the first spray pipe (24) and the second spray pipe (25). A second solenoid valve (18) is installed on the first spray pipe (24) and a first solenoid valve (15) is installed on the second spray pipe (25). A housing (7), blades (6) and a sliding frame (3) are arranged sequentially on the shaft (1) away from the rotor body. The sliding frame (3) can slide along the axial direction of the shaft (1). An air guide annular groove (8) is opened on the outer periphery of the housing (7). The rotating shaft (1) is provided with an air passage cavity. The rotating shaft (1) is provided with a first through hole (10) and a second through hole (11) that connect the air passage cavity. The first through hole (10) is connected to the inner cavity of the box (7). The blade (6) is located between the first through hole (10) and the second through hole (11). A power assembly (2) that can drive the sliding frame (3) to move along the axis of the rotating shaft (1) is installed on the rotating shaft (1) or on the motor housing (23). When the round tube (4) abuts against the stator assembly (5), the sliding bracket (3) completely blocks the second through hole (11), the first solenoid valve (15) closes and the second solenoid valve (18) opens; When the round tube (4) abuts against the baffle (26) or the motor housing (23), the sliding frame (3) and the second through hole (11) are misaligned, the first solenoid valve (15) is opened and the second solenoid valve (18) is closed.

2. The spray-cooled motor for a semi-hermetic centrifugal compressor according to claim 1, characterized in that: The heat dissipation channel on the stator assembly (5) includes several accommodating spaces. Any two adjacent accommodating spaces are staggered around the stator assembly (5) and partially connected along the axial direction.

3. The spray-cooled motor for a semi-hermetic centrifugal compressor according to claim 1, characterized in that: The stator assembly (5) is provided with an annular plate (9) near the housing (7). The outer diameter of the annular plate (9) is smaller than the inner diameter of the circular tube (4), and the inner diameter of the annular plate (9) is larger than the outer diameter of the housing (7) and the inner diameter of the stator assembly (5).

4. The spray-cooled motor for a semi-hermetic centrifugal compressor according to claim 1, characterized in that: The motor housing (23) has an opening that connects to the cooling cavity, and the opening is connected to one end of the first connecting pipe (14).

5. The spray-cooled motor for a semi-hermetic centrifugal compressor according to claim 1, characterized in that: Both the first spray pipe (24) and the second spray pipe (25) are arc-shaped.

6. The spray-cooled motor for a semi-hermetic centrifugal compressor according to claim 1, characterized in that: The sliding frame (3), connector (13) and round tube (4) are integrally formed.

7. The spray-cooled motor for a semi-hermetic centrifugal compressor according to claim 1, characterized in that: The power component (2) is an electromagnet, and the sliding frame (3) is a magnetic attraction component.

8. The spray-cooled motor for a semi-hermetic centrifugal compressor according to claim 7, characterized in that: An elastic element (12) is installed on the connector (13), and the elastic element (12) abuts against the baffle (26) or the motor housing (23).

9. The spray-cooled motor for a semi-hermetic centrifugal compressor according to claim 1, characterized in that: The outer periphery of the round tube (4) is provided with oil-absorbing felt.

10. A waste heat recovery system, used in conjunction with the spray cooling motor of the semi-hermetic centrifugal compressor as described in claim 1, characterized in that: The motor housing (23) has an opening that connects to the cooling cavity. The opening is connected to one end of the first connecting pipe (14), the other end of the first connecting pipe (14) is connected to the first inlet of the electromagnetic proportional valve (20), the other inlet of the electromagnetic proportional valve (20) is connected to one end of the fifth connecting pipe (27), and the outlet of the electromagnetic proportional valve (20) is connected to one end of the manifold (21). The second solenoid valve (18) is connected to the first connection port of the three-way pipe (19), the second connection port of the three-way pipe (19) is connected to the first solenoid valve (15) through the second connection pipe (16), and the third connection port of the three-way pipe (19) is connected to one end of the fourth connection pipe (22).

Images