A semi-hermetic screw refrigerating machine for centralized refrigeration

Abstract

The application discloses a kind of semi-closed screw refrigerators for centralized refrigeration, belong to refrigeration machine technical field, including evaporator shell and condenser shell, multiple U-shaped sleeves are fixedly connected to multiple U-shaped sleeves in evaporator shell inner side wall by multiple groups of distribution support plates, the outer side wall of adjacent two U-shaped sleeves is connected with the elastic baffle cover for adjusting the pressure of upper and lower space in evaporator shell by pressure regulating assembly, and compression pipe shell is arranged on evaporator shell.The application can indirectly judge the aging condition of oil product by using the hindering effect of capillary groove on lubricating oil flow by the setting of flow measuring plate and sliding assembly, realizes built-in passive monitoring, provides judgment basis for lubricating oil replacement, is better than traditional periodic replacement or external oil sample analysis, more real-time and economical, and simultaneously triggers circuit alarm by the frictional resistance change of sliding block, can early discover rotor wear, lubricating oil emulsification or foreign matter invasion and other abnormal working conditions, greatly improves the safety of operation.

Description

Technical Field

[0001] This invention relates to the field of refrigeration technology, and in particular to a semi-hermetic screw refrigeration unit for centralized refrigeration. Background Technology

[0002] A semi-hermetic screw chiller is a core component of a refrigeration system that integrates a screw compressor, motor, oil separator, and necessary control components into a detachable housing.

[0003] The lubricating oil in the screw compressor section of a refrigeration unit fills the gap between the rotor and the housing, forms an oil film to protect the bearings and meshing surfaces, and absorbs the heat of compression. Healthy lubricating oil is crucial for the safe and stable operation of the equipment. However, current methods mainly rely on periodic sampling for laboratory analysis. This method is offline and periodic, and cannot reflect the instantaneous deterioration of the oil during operation (such as sudden water ingress and emulsification, or high-temperature degradation). At the same time, abnormalities such as wear and scratches on the male and female rotors are extremely difficult to detect in the early stages. They are usually only detected when there is severe vibration, noise, or a significant drop in performance. By this time, irreversible damage may have already occurred. Subsequent maintenance is planned or remedial, which has a certain lag and cannot achieve early warning of faults. This increases the risk of unexpected downtime and the cost of major repairs. Based on this, a semi-hermetic screw refrigeration unit for centralized refrigeration is proposed. Summary of the Invention

[0004] The purpose of this invention is to solve the problems existing in the prior art by proposing a semi-hermetic screw chiller for centralized refrigeration.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A semi-hermetic screw chiller for centralized refrigeration includes an evaporator shell and a condenser shell. The inner wall of the evaporator shell is fixedly connected to a U-shaped sleeve by multiple sets of distributed support plates. The outer walls of adjacent U-shaped sleeves are connected to elastic baffles for adjusting the pressure of the upper and lower spaces inside the evaporator shell by a pressure regulating assembly. A compression shell is provided on the evaporator shell, and a twin-screw compression assembly for pressurizing the gaseous refrigerant generated in the evaporator shell is provided inside the compression shell.

[0007] The twin-screw compressor assembly is equipped with a slide valve, and a heat dissipation fin is connected to the bottom of the slide valve. A flow measuring plate is slidably connected to the bottom of the heat dissipation fin via a fixed rod. The flow measuring plate has a capillary groove for monitoring the flow of lubricating oil on the twin-screw compressor assembly. A sliding component for monitoring the surface smoothness of the twin-screw compressor assembly is provided at the bottom of the heat dissipation fin. A retaining tube is fixed to the end of the compression tube shell. A sealing assembly is provided inside the retaining tube. A compressor end cover is provided on the outside of the sealing assembly.

[0008] Preferably, both ends of the evaporator shell and the condenser shell are fixed with frames, a control cabinet is fixedly installed on the evaporator shell, and a double pipe joint communicating with the end of the U-shaped sleeve is fixedly installed at the end of the evaporator shell.

[0009] Preferably, the pressure regulating component includes a double-hole sleeve fixed on two adjacent U-shaped sleeves. The double-hole sleeve is fixedly connected to an elastic baffle through two hydraulic push rods. The elastic baffle has multiple connecting holes. The double-hole sleeves are arranged in three groups in parallel.

[0010] Preferably, the twin-screw compression assembly includes a fluorine-resistant motor fixed inside the compression tube shell, and the output end of the fluorine-resistant motor is connected to a male rotor and a female rotor via a transmission box, wherein the male rotor and the female rotor mesh with each other.

[0011] Preferably, the slide valve is disposed on the meshing area of ​​the male rotor and the female rotor, the slide valve is connected to the fixed tube through the loading oil valve, and multiple sets of interval grooves are opened at the bottom of the heat dissipation fin.

[0012] Preferably, the sliding end of the flow measuring plate and the fixed rod is made of magnetic material, a buffer magnetic ring is fixedly connected to the outer wall of the fixed rod, and a capillary oil quality sensor for monitoring the flow of lubricating oil is provided at the end of the capillary groove of the flow measuring plate.

[0013] Preferably, the sliding assembly includes a sliding block that slides on the bottom of the heat dissipation fins. Two fixed plates are slidably connected to both ends of the sliding block by two sliding rods. Movable electrodes are fixed at both ends of the sliding block. Fixed electrodes are fixed inside the fixed plates. A signal feedback instrument electrically connected to the movable electrodes is provided inside the sliding block.

[0014] Preferably, the sealing assembly includes an exhaust pressure plate slidably disposed within the retaining tube, the end of the exhaust pressure plate being fixed with a centering shaft, the outer side wall of the end of the retaining tube being provided with an external thread, and the inner side wall of the compressor end cover being provided with an internal thread for threaded connection with the retaining tube.

[0015] Preferably, a locking flange is fixed to the outer wall of the locating tube, and multiple locking bolts are threaded onto the locking flange. Multiple locking grooves corresponding to the locking bolts are opened on the outer wall of the exhaust pressure plate. A rubber pad is provided on the inner end face of the compressor end cover. Both the rubber pad and the compressor end cover are provided with centering holes adapted to the centering shaft.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. This solution, through the setting of the pressure regulating component, can use the position of the slide valve to control the elastic baffle, and adjust the flow cross-sectional area of ​​the refrigerant in the evaporator shell in real time, thereby actively controlling the evaporation rate and return gas volume. This allows the evaporator shell to actively adapt to the changes in the operating conditions in the compression tube shell, improve the overall system efficiency and response speed, and avoid the problem of mismatch between gas supply and compression conditions.

[0018] 2. This solution, through the setting of the flow measuring plate and sliding component, can indirectly judge the aging of the oil by utilizing the obstruction effect of the capillary groove on the flow of lubricating oil, realizing built-in passive monitoring and providing a basis for judging the replacement of lubricating oil. It is superior to the traditional periodic replacement or external oil sample analysis, and is more real-time and economical. At the same time, the circuit alarm is triggered by the change of frictional resistance of the sliding block, which can detect abnormal conditions such as rotor wear, lubricating oil emulsification or foreign object intrusion at an early stage, greatly improving the safety of operation.

[0019] 3. This solution, through the setting of sealed assembly components, can solve problems such as incomplete venting of the bearing cavity, uneven stress on the sealing surface, and misalignment of threads during the assembly and maintenance of semi-enclosed units, avoiding potential hazards such as leakage, vibration, and malfunctions. The fit between the central shaft and the centering hole ensures the concentricity of the threaded connection, avoiding damage to the sealing surface and stress concentration caused by misalignment. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural schematic diagram of a semi-hermetic screw chiller for centralized refrigeration proposed in this invention;

[0021] Figure 2 This is an overall assembly drawing of a semi-hermetic screw chiller for centralized refrigeration proposed in this invention;

[0022] Figure 3 This is a schematic diagram of the internal structure of the evaporator shell in a semi-hermetic screw chiller for centralized refrigeration proposed in this invention;

[0023] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0024] Figure 5 This is a schematic diagram of the pressure regulating component in a semi-hermetic screw chiller for centralized refrigeration proposed in this invention;

[0025] Figure 6 This is a schematic diagram of the internal structure of the compression tube shell in a semi-hermetic screw chiller for centralized refrigeration proposed in this invention;

[0026] Figure 7 This is a schematic diagram of the heat dissipation fin position in a semi-hermetic screw chiller for centralized refrigeration proposed in this invention;

[0027] Figure 8 for Figure 7 Enlarged view of point B in the middle;

[0028] Figure 9 This is a cross-sectional view of the capillary groove of the flow plate in a semi-hermetic screw chiller for centralized refrigeration proposed in this invention.

[0029] Figure 10 This is a schematic diagram of the sliding component in a semi-hermetic screw chiller for centralized refrigeration proposed in this invention;

[0030] Figure 11 This is a schematic diagram of the sealing assembly component in a semi-hermetic screw chiller for centralized refrigeration proposed in this invention.

[0031] In the diagram: 1. Evaporator shell; 2. Condenser shell; 3. Frame; 4. Control cabinet; 5. Double pipe joint; 6. Distribution support plate; 7. U-shaped sleeve; 8. Double-hole sleeve; 9. Hydraulic push rod; 10. Elastic baffle; 11. Compression pipe shell; 12. Fluorine-resistant motor; 13. Male rotor; 14. Female rotor; 15. Loading oil valve; 16. Slide valve; 17. Heat dissipation fins; 18. Flow measuring plate; 19. Buffer magnetic ring; 20. Sliding block; 21. Moving electrode; 22. Fixed electrode; 23. Fixing tube; 24. Exhaust pressure plate; 25. Centering shaft; 26. Locking flange; 27. Rubber gasket; 28. Compressor end cover. Detailed Implementation

[0032] 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.

[0033] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] Example, refer to Figures 1 to 11 A semi-hermetic screw chiller for centralized refrigeration includes an evaporator shell 1 and a condenser shell 2. The inner wall of the evaporator shell 1 is fixedly connected to a U-shaped sleeve 7 by multiple sets of distributed support plates 6. The outer walls of adjacent U-shaped sleeves 7 are connected to elastic baffles 10 for adjusting the pressure of the upper and lower spaces inside the evaporator shell 1 by a pressure regulating component.

[0036] Furthermore, a frame 3 is fixed at both ends of the evaporator shell 1 and the condenser shell 2. A control cabinet 4 is fixedly installed on the evaporator shell 1. A double pipe joint 5 connected to the end of the U-shaped sleeve 7 is fixedly installed at the end of the evaporator shell 1. The pressure regulating component includes a double-hole sleeve 8 fixed on two adjacent U-shaped sleeves 7. The double-hole sleeve 8 is fixedly connected to the elastic baffle 10 through two hydraulic push rods 9. The elastic baffle 10 has multiple connecting holes. The double-hole sleeve 8 is arranged in three groups in parallel.

[0037] It should be noted that: when chilled water is introduced into the U-shaped sleeve 7 from one end of the double-pipe connector 5 and then flows out from the other end of the double-pipe connector 5 through the U-shaped sleeve 7, the low-temperature, low-pressure liquid refrigerant in the evaporator shell 1 absorbs heat from the chilled water in the U-shaped sleeve 7, causing the refrigerant to change from liquid to gaseous state and enter the compression shell 11 from the evaporator shell 1. During this process, based on the sliding state of the slide valve 16 in the compression shell 11, i.e., the pressurization state of the compressed gaseous refrigerant in the compression shell 11, the hydraulic push rod 9 on the double-hole sleeve 8 is linked to control the advancement and retraction of the hydraulic push rod 9. If it is necessary to pressurize the refrigerant in the upper part of the evaporator shell 1, the hydraulic push rod 9 on the three sets of parallel double-hole sleeves 8 is controlled to pull the elastic baffle 10 upward. The elastic baffle 10 undergoes elastic deformation in the evaporator shell 1, causing the connecting hole on the elastic baffle 10 to close under elastic deformation, continuously pressurizing the refrigerant above, thereby increasing the flow into the compression shell. If the gaseous refrigerant in the evaporator shell 1 needs to be depressurized, the hydraulic push rods 9 on both sides of the double-hole sleeve 8 will pull the elastic baffle 10 up slightly, and the hydraulic push rod 9 in the middle will push the elastic baffle 10 down, so that the elastic baffle 10 will be in a V-shape and undergo elastic deformation. The connecting hole on the elastic baffle 10 will expand due to the elastic deformation, which will facilitate the refrigerant flowing back from the bottom of the evaporator shell 1 into the top. The depressurized and continuously flowing low-temperature refrigerant will absorb heat from the higher-temperature chilled water above (the chilled water flows continuously in the U-shaped sleeve 7, and its temperature decrease is also a continuous process. Overall, the temperature of the chilled water in the upper part of the U-shaped sleeve 7 is higher than that of the chilled water in the lower part), which will better cool the chilled water. In this way, the state of the elastic baffle 10 can be adjusted according to the pressure adjustment of the slide valve 16 in the compression tube shell 11, thereby changing the generation rate of gaseous refrigerant in the evaporator shell 1.

[0038] The advantages mentioned above are: to increase or decrease the generation rate of gaseous refrigerant in the evaporator shell 1, to meet the continuous pressurization or depressurization of gaseous refrigerant in the compression shell 11 (the continuous depressurization here is depressurization from a higher gas pressure state, which is still a pressurized condition compared to the evaporator shell 1), to facilitate adaptation to the compression conditions in the compression shell 11, and to avoid the situation where the gas supply is incompatible with the compression conditions.

[0039] An evaporator housing 1 is provided with a compression tube shell 11. Inside the compression tube shell 11 is a twin-screw compressor assembly for pressurizing the gaseous refrigerant generated in the evaporator housing 1. The twin-screw compressor assembly is provided with a slide valve 16. The bottom of the slide valve 16 is connected to a heat dissipation fin 17. The bottom of the heat dissipation fin 17 is slidably connected to a flow measuring plate 18 via a fixed rod. The flow measuring plate 18 has a capillary groove for monitoring the flow of lubricating oil on the twin-screw compressor assembly. The bottom of the heat dissipation fin 17 is provided with a sliding component for monitoring the surface smoothness of the twin-screw compressor assembly.

[0040] Furthermore, the twin-screw compression assembly includes a fluorine-resistant motor 12 fixed inside the compression tube shell 11. The output end of the fluorine-resistant motor 12 is connected to a male rotor 13 and a female rotor 14 via a transmission box. The male rotor 13 and the female rotor 14 mesh with each other. A slide valve 16 is set on the meshing area of ​​the male rotor 13 and the female rotor 14. The slide valve 16 is connected inside the fixed tube 23 via a loading oil valve 15. Multiple sets of interval slots are opened at the bottom of the heat dissipation fin plate 17. The sliding end of the flow measuring plate 18 and the fixed rod is made of magnetic material. A buffer magnetic ring 19 is fixedly connected to the outer wall of the fixed rod. A capillary oil quality sensor for monitoring the flow of lubricating oil is set at the end of the capillary groove of the flow measuring plate 18. The sliding assembly includes a sliding block 20 sliding on the bottom of the heat dissipation fin plate 17. Two fixed plates are slidably connected to both ends of the sliding block 20 via two slide rods. Movable electrodes 21 are fixed at both ends of the sliding block 20. Fixed electrodes 22 are fixed inside the fixed plates. A signal feedback instrument electrically connected to the movable electrodes 21 is set inside the sliding block 20.

[0041] It should be noted that during the compression of gaseous refrigerant, the fluorine-resistant motor 12 drives the meshing rotation between the male rotor 13 and the female rotor 14. During this process, the lubricating oil between the male rotor 13 and the female rotor 14 fills the gap between the rotor and the housing, forms an oil film to protect the bearings and meshing surfaces, and absorbs the heat of compression. The heat dissipation fins 17 at the bottom of the slide valve 16 also absorb some of the heat of compression. Because the rotation of the male rotor 13 and the female rotor 14 is a continuous forward pushing motion, and the forward push of the slide valve 16 scrapes the lubricating oil, some lubricating oil will enter the capillary groove of the flow measuring plate 18 under this condition. Due to the narrow channel of the capillary groove, there will be a certain capillary force on the lubricating oil, hindering its flow. If the lubricating oil leaks out... As the lubricant ages, its viscosity increases and its fluidity decreases. Therefore, even when the slide valve 16 is pushed forward to its maximum distance (at which point the most lubricating oil can be pressed into the capillary groove), the lubricating oil cannot flow out of the capillary groove. This facilitates regular monitoring of the lubricating oil status in the compression tube shell 11, which is convenient for subsequent daily maintenance and fault diagnosis. During the sliding of the slide valve 16, the sliding block 20 also slides on the meshing surface of the male rotor 13 and the female rotor 14. If wear or lubricating oil emulsification occurs on the meshing surface of the male rotor 13 and the female rotor 14, the sliding friction of the sliding block 20 will increase, causing the moving electrode 21 to connect with the fixed electrode 22. This allows the external circuit to activate the signal feedback instrument inside the sliding block 20 and issue a warning signal.

[0042] The advantages mentioned above are: it facilitates timely detection of abnormal operating conditions between the male rotor 13 and the female rotor 14, ensuring the safe use of the male rotor 13 and the female rotor 14.

[0043] A retaining tube 23 is fixed at the end of the compression tube shell 11. A sealing assembly is provided inside the retaining tube 23, and a compressor end cover 28 is provided on the outside of the sealing assembly.

[0044] Furthermore, the sealing assembly includes an exhaust pressure plate 24 slidably disposed within the retaining tube 23, an alignment shaft 25 fixed to the end of the exhaust pressure plate 24, an external thread on the outer side wall of the end of the retaining tube 23, an internal thread for threaded connection with the retaining tube 23 on the inner side wall of the compressor end cover 28, a locking flange 26 fixed to the outer side wall of the retaining tube 23, a plurality of locking bolts threadedly connected to the locking flange 26, a plurality of locking grooves corresponding to the locking bolts on the outer side wall of the exhaust pressure plate 24, a rubber pad 27 disposed on the inner end face of the compressor end cover 28, and alignment holes adapted to the alignment shaft 25 are provided on both the rubber pad 27 and the compressor end cover 28;

[0045] It should be noted that during the production and assembly of the compressor housing 11 of the refrigeration unit and the subsequent disassembly and maintenance, the exhaust pressure plate 24 is first slid towards the compressor housing 11 to discharge the gas in the bearing and connection end area of ​​the compressor housing 11. Then, the exhaust pressure plate 24 is slid outward to the end of the fixed tube 23 and stops. At this time, the locking groove on the exhaust pressure plate 24 corresponds one-to-one with the position of the locking bolt on the locking flange 26. Tightening the locking bolt limits the position of the exhaust pressure plate 24. Then, the centering hole of the rubber pad 27 and the compressor end cover 28 is aligned with the centering shaft 25, and the compressor end cover 28 is continuously tightened on the fixed tube 23.

[0046] The advantages mentioned above are as follows: the threaded connection with the axial alignment avoids pressure damage to the threaded area, which would cause sealing defects. During this process, the exhaust pressure plate 24 will continuously press the rubber gasket 27, causing the rubber gasket 27 to undergo elastic deformation and press the connection part, ensuring the overall sealing state after assembly.

[0047] In use, the oil separator, control cabinet 4, and condenser shell 2 in the refrigeration unit are all conventional designs in the prior art and will not be described further. Chilled water is introduced into the U-shaped sleeve 7 from one end of the double-pipe connector 5, and then flows out from the other end of the double-pipe connector 5 through the U-shaped sleeve 7. The low-temperature, low-pressure liquid refrigerant in the evaporator shell 1 absorbs heat from the chilled water in the U-shaped sleeve 7, causing the refrigerant to change from liquid to gaseous state and enter the compression shell 11 from the evaporator shell 1. During this process, the sliding state of the slide valve 16 inside the compression shell 11 determines the compression... The pressurization of the gaseous refrigerant is controlled by the hydraulic push rods 9 on the double-hole sleeve 8, which advance and retract. If pressurization of the refrigerant in the upper part of the evaporator shell 1 is required, the hydraulic push rods 9 on the three parallel sets of double-hole sleeves 8 are controlled to pull the elastic baffle 10 upward. The elastic baffle 10 undergoes elastic deformation within the evaporator shell 1, causing the connecting holes on the elastic baffle 10 to close under elastic deformation, continuously pressurizing the refrigerant above, thereby increasing the amount of gaseous refrigerant flowing into the compression pipe shell 11. If depressurization of the refrigerant in the upper part of the evaporator shell 1 is required, the double-hole sleeves on both sides are controlled... The hydraulic push rod 9 on the sleeve 8 slightly pulls the elastic baffle 10 upwards, causing the middle hydraulic push rod 9 to push the elastic baffle 10 downwards, resulting in a V-shaped elastic deformation of the elastic baffle 10. This deformation enlarges the connecting hole on the elastic baffle 10, facilitating the compression of the refrigerant flowing back from below the evaporator shell 1 into the upper part. The depressurized and continuously flowing low-temperature refrigerant then absorbs heat from the higher-temperature chilled water above (the chilled water continuously flows within the U-shaped sleeve 7, and its temperature decrease is a continuous process; overall, the temperature of the chilled water above the U-shaped sleeve 7 is higher than that of the chilled water below). The chilled water is cooled more effectively. This allows the state of the elastic baffle 10 to be adjusted according to the pressure regulation of the slide valve 16 in the compression shell 11, thereby changing the generation rate of gaseous refrigerant in the evaporator shell 1. This increases or decreases the generation rate of gaseous refrigerant in the evaporator shell 1, satisfying the continuous pressurization or depressurization of gaseous refrigerant in the compression shell 11 (here, continuous depressurization is depressurization from a higher gas pressure state, which is still a pressurized condition compared to the evaporator shell 1). This facilitates adaptation to the compression conditions in the compression shell 11 and avoids situations where the gas supply is incompatible with the compression conditions.

[0048] When compressing gaseous refrigerant, the fluorine-resistant motor 12 drives the meshing rotation between the male rotor 13 and the female rotor 14. During this process, the lubricating oil between the male rotor 13 and the female rotor 14 fills the gap between the rotor and the housing, forms an oil film to protect the bearings and meshing surfaces, and absorbs the heat of compression. The heat dissipation fins 17 at the bottom of the slide valve 16 also absorb some of the heat of compression. Since the rotation of the male rotor 13 and the female rotor 14 is a continuous forward pushing motion, and the forward push of the slide valve 16 scrapes the lubricating oil, some lubricating oil will enter the capillary groove of the flow measuring plate 18 under this condition. Due to the narrow channel of the capillary groove, there will be a certain capillary force on the lubricating oil, which will hinder the flow of the lubricating oil. If the lubricating oil is aged, its viscosity will increase and its fluidity will be insufficient, thus causing the lubricating oil to flow forward in front of the slide valve 16. When pushed to the maximum distance (at which point the most lubricating oil can be pressed into the capillary groove), the lubricating oil cannot flow out of the capillary groove. This facilitates regular monitoring of the lubricating oil status in the compression tube shell 11, and facilitates subsequent daily maintenance and fault diagnosis. During the sliding of the slide valve 16, the sliding block 20 will also slide on the meshing surface of the male rotor 13 and the female rotor 14. If wear or lubricating oil emulsification occurs on the meshing surface of the male rotor 13 and the female rotor 14, the sliding friction of the sliding block 20 will increase, causing the active electrode 21 to connect with the fixed electrode 22. This allows the external circuit to activate the signal feedback instrument inside the sliding block 20 and issue a warning signal, making it easy to detect abnormal operating conditions between the male rotor 13 and the female rotor 14 in a timely manner and ensuring the safe use of the male rotor 13 and the female rotor 14.

[0049] During the production, assembly, and subsequent disassembly and maintenance of the compressor housing 11 of the refrigeration unit, the exhaust pressure plate 24 is first slid towards the compressor housing 11 to expel the gas from the bearing and connection end areas of the compressor housing 11. Then, the exhaust pressure plate 24 is slid outward to the end of the retaining tube 23 and stops. At this time, the locking groove on the exhaust pressure plate 24 corresponds one-to-one with the position of the locking bolt on the locking flange 26. Tightening the locking bolt limits the position of the exhaust pressure plate 24. Then, the centering holes of the rubber gasket 27 and the compressor end cover 28 are aligned with the centering shaft 25, and the compressor end cover 28 is continuously tightened on the retaining tube 23. The threaded connection with the axial alignment avoids damage to the threaded area, which would cause sealing defects. During this process, the exhaust pressure plate 24 continuously presses the rubber gasket 27, causing the rubber gasket 27 to elastically deform and press the connection part, ensuring the overall sealing state after assembly.

[0050] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A semi-hermetic screw chiller for centralized refrigeration, comprising an evaporator shell (1) and a condenser shell (2), characterized in that, The inner wall of the evaporator housing (1) is fixedly connected to a U-shaped sleeve (7) by multiple sets of distributed support plates (6). The outer walls of the adjacent U-shaped sleeve (7) are connected to an elastic baffle (10) for adjusting the pressure of the upper and lower space inside the evaporator housing (1) by a pressure regulating assembly. A compression shell (11) is provided on the evaporator housing (1). A twin-screw compression assembly for pressurizing the gaseous refrigerant generated in the evaporator housing (1) is provided inside the compression shell (11). The twin-screw compressor assembly is provided with a slide valve (16), and a heat dissipation fin (17) is connected to the bottom of the slide valve (16). A flow measuring plate (18) is slidably connected to the bottom of the heat dissipation fin (17) through a fixed rod. A capillary groove for monitoring the flow of lubricating oil on the twin-screw compressor assembly is opened in the flow measuring plate (18). A sliding component for monitoring the surface smoothness of the twin-screw compressor assembly is provided at the bottom of the heat dissipation fin (17). A retaining tube (23) is fixed at the end of the compression tube shell (11). A sealing assembly is provided inside the retaining tube (23). A compressor end cover (28) is provided on the outside of the sealing assembly.

2. The semi-hermetic screw chiller for centralized refrigeration according to claim 1, characterized in that, Both ends of the evaporator shell (1) and the condenser shell (2) are fixed with frames (3), a control cabinet (4) is fixedly installed on the evaporator shell (1), and a double pipe joint (5) connected to the end of the U-shaped sleeve (7) is fixedly installed at the end of the evaporator shell (1).

3. A semi-hermetic screw chiller for centralized refrigeration according to claim 1, characterized in that, The pressure regulating component includes a double-hole sleeve (8) fixed on two adjacent U-shaped sleeves (7). The double-hole sleeve (8) is fixedly connected to an elastic baffle (10) through two hydraulic push rods (9). The elastic baffle (10) has multiple connecting holes. The double-hole sleeve (8) is arranged in three parallel groups.

4. A semi-hermetic screw chiller for centralized refrigeration according to claim 1, characterized in that, The twin-screw compression assembly includes a fluorine-resistant motor (12) fixed inside the compression tube shell (11). The output end of the fluorine-resistant motor (12) is connected to a male rotor (13) and a female rotor (14) via a transmission box. The male rotor (13) and the female rotor (14) mesh with each other.

5. A semi-hermetic screw chiller for centralized refrigeration according to claim 1, characterized in that, The slide valve (16) is located in the meshing area of ​​the male rotor (13) and the female rotor (14). The slide valve (16) is connected to the fixed tube (23) through the loading oil valve (15). Multiple sets of interval grooves are opened at the bottom of the heat dissipation fin (17).

6. A semi-hermetic screw chiller for centralized refrigeration according to claim 1, characterized in that, The sliding end of the flow measuring plate (18) and the fixed rod is made of magnetic material. A buffer magnetic ring (19) is fixedly connected to the outer wall of the fixed rod. A capillary oil quality sensor for monitoring the flow of lubricating oil is provided at the end of the capillary groove of the flow measuring plate (18).

7. A semi-hermetic screw chiller for centralized refrigeration according to claim 1, characterized in that, The sliding assembly includes a sliding block (20) that slides on the bottom of the heat dissipation fin (17). The two ends of the sliding block (20) are slidably connected to two fixed plates by two sliding rods. Both ends of the sliding block (20) are fixed with movable electrodes (21). Fixed electrodes (22) are fixed inside the fixed plates. A signal feedback instrument electrically connected to the movable electrodes (21) is provided inside the sliding block (20).

8. A semi-hermetic screw chiller for centralized refrigeration according to claim 1, characterized in that, The sealing assembly includes an exhaust pressure plate (24) that is slidably disposed in the retaining tube (23). The end of the exhaust pressure plate (24) is fixed with a centering shaft (25). The outer side wall of the end of the retaining tube (23) is provided with an external thread, and the inner side wall of the compressor end cover (28) is provided with an internal thread for threaded connection with the retaining tube (23).

9. A semi-hermetic screw chiller for centralized refrigeration according to claim 8, characterized in that, The outer wall of the fixed tube (23) is fixed with a locking flange (26), and multiple locking bolts are threaded onto the locking flange (26). Multiple locking grooves corresponding to the locking bolts are opened on the outer wall of the exhaust pressure plate (24). A rubber pad (27) is provided on the inner end face of the compressor end cover (28). Both the rubber pad (27) and the compressor end cover (28) are provided with centering holes that are compatible with the centering shaft (25).

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