A twin-screw compressor unit

Abstract

The present invention relates to the technical field of compressor cooling units, and in particular to a twin-screw compressor unit; the twin-screw compressor unit can increase the inlet temperature and pressure of gaseous refrigerant, reduce the internal limit temperature difference of the screw compressor, improve the internal temperature balance of the screw compressor and the compression efficiency of the gaseous refrigerant; it comprises a first unit and an evaporator, the first unit comprises a screw compressor body, an oil-gas separator, a condenser and a throttling and pressure-reducing component connected in sequence; the first unit also comprises a return air pipeline, a warming and boosting device, an oil-gas pipeline and an oil return component; the screw compressor body comprises a shell, a male screw rotatably installed in the shell, a female screw rotatably installed in the shell and meshing with the male screw, and a driving motor that provides power for the rotation of the male screw, and a hollow cavity is provided inside the female screw; the warming and boosting device is used for heating and pressurizing the low-temperature and low-pressure gaseous refrigerant refluxed at the evaporator.

Description

Technical Field

[0001] The invention relates to the technical field of compressor cooling units, and in particular to a twin-screw compressor unit. Background Art

[0002] As we all know, screw compressors are composed of a pair of parallel, intermeshing female and male screws, and are the most widely used type of rotary compressors. They are divided into single screw and twin screw. The screw compressors usually refer to twin screw compressors. Screw compressors are an important part of refrigeration units.

[0003] For example, Chinese utility model patent CN217274923U discloses a dual compressor water-cooled screw chiller, including: a screw compressor assembly, an evaporator assembly, a condenser assembly, a refrigerant pipeline and a water pipeline system, wherein the evaporator assembly and the condenser assembly are connected to the screw compressor assembly through the refrigerant pipeline, the evaporator assembly is connected to the condenser assembly, and the water pipeline system is connected to the evaporator assembly and the condenser assembly. Compared with the traditional technology, it realizes automatic circulation cooling, is convenient and fast, and is energy-saving and low-consumption.

[0004] However, the following defects were found: the gaseous refrigerant entering the screw compressor is in a low-temperature and low-pressure state. After the female and male screws in the screw compressor have worked for a long time, the internal temperature of the screw compressor increases due to friction and the compression work of the gaseous refrigerant. The temperature difference between the gaseous refrigerant and the inside of the screw compressor is large (the temperature difference is greater than 100°C). The entry of low-temperature refrigerant causes uneven temperatures near the air inlet and outlet of the screw compressor. The female and male screws near the air inlet and outlet are slightly deformed due to uneven heating, which accelerates the wear of the female and male screws and affects the meshing degree of the female and male screws. The intake pressure of the gaseous refrigerant entering the screw compressor is low, which leads to a decrease in the density of the gaseous refrigerant, which in turn affects the suction volume of the screw compressor, resulting in a reduction in the actual exhaust volume of the compressor, thereby affecting the compression efficiency and affecting the compression efficiency of the screw compressor for gaseous refrigerant. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a twin-screw compressor unit which can increase the inlet temperature and pressure of the gaseous refrigerant, reduce the internal limit temperature difference of the screw compressor, improve the internal temperature balance of the screw compressor and the compression efficiency of the gaseous refrigerant.

[0006] To achieve the above object, the present invention provides the following technical solution: a twin-screw compressor unit, comprising a first unit and an evaporator, wherein the first unit comprises a screw compressor body, an oil-gas separator, a condenser and a throttling and pressure reduction assembly connected in sequence; the first unit also comprises a return air pipeline, a temperature increasing and supercharging device, an oil-gas pipeline and an oil return assembly;

[0007] The screw compressor body includes a shell, a male screw rotatably installed in the shell, a female screw rotatably installed in the shell and meshing with the male screw, and a driving motor that provides power for the rotation of the male screw. A hollow cavity is provided inside the female screw. One end of the return air pipeline is connected to the air outlet on the evaporator, and the other end of the return air pipeline is connected to the air inlet end of the warming supercharger. The air outlet end of the warming supercharger is connected to the air inlet on the shell. One end of the oil and gas pipeline is connected to the air outlet on the shell. The other end of the oil-gas pipeline is connected to the air inlet on the oil-gas separator, and the oil return assembly includes an oil return pump and an oil return pipeline. The input end of the oil return pump extends to the bottom of the oil-gas separator, and the output end of the oil return pump is connected to the input end of the oil return pipeline, and the output end of the oil return pipeline extends from the upper part of the shell into the shell; the warming and boosting device is used for heating and pressurizing the low-temperature and low-pressure gaseous refrigerant refluxed from the evaporator; further, the warming and boosting device can use an electric auxiliary heating vacuum pump for pressurization and heating.

[0008] Preferably, the temperature increasing supercharger includes a mounting shell, an air inlet cylinder fixedly mounted on the mounting shell, an air outlet cylinder fixedly mounted on the mounting shell and vertically offset with the air inlet cylinder, a connecting pipe with two ends respectively communicating with the interior of the air inlet cylinder and the air outlet cylinder, a first piston slidably mounted in the air inlet cylinder, a second piston slidably mounted in the air outlet cylinder, and a driving member for driving the first piston and the second piston to slide.

[0009] The air inlet cylinder is provided with an air inlet pipe connected to the interior of the air inlet cylinder, and a first one-way valve is installed in the air inlet pipe to allow gas to enter the air inlet cylinder in one direction. The output end of the return air pipeline is connected to the input end of the air inlet pipe, and a second one-way valve is provided at the connection between the connecting pipe and the air outlet cylinder to allow gas in the connecting pipe to enter the air outlet cylinder in one direction. The air outlet cylinder is provided with an air outlet pipe connected to the air inlet end of the shell; the driving member can adopt two driving cylinders, the two driving cylinders are fixedly installed in the mounting shell, and the first piston and the second piston are driven respectively by the two driving cylinders.

[0010] Preferably, a driving shaft is rotatably mounted on the mounting shell, and the driving member includes a first eccentric cam fixedly connected to the driving shaft, a first connecting shaft fixedly mounted on the first eccentric cam and away from the central axis of the driving shaft, a second eccentric cam rotatably mounted on the inner wall of the mounting shell, a second connecting shaft fixedly mounted on the second eccentric cam and away from the central axis of the driving shaft, a right-angle connecting plate, a first driving handle and a second driving handle, the first eccentric cam and the second eccentric cam are vertically arranged, the first connecting shaft and the second connecting shaft are fixedly connected by the right-angle connecting plate, one end of the first driving handle is rotatably connected to the first connecting shaft, the other end of the first driving handle is rotatably connected to the second piston, one end of the second driving handle is rotatably connected to the second connecting shaft, the other end of the second driving handle is rotatably connected to the first piston, and the driving shaft is transmission-connected to the male screw; further, the driving shaft is fixedly connected to the male screw.

[0011] Preferably, a bypass pipe is further included, a Venturi jet tube is installed on the oil return pipeline, an annular cavity is provided on the Venturi jet tube, a plurality of air inlet holes communicating with the annular cavity are provided at the neck of the Venturi jet tube, one end of the bypass pipe is communicated with the air outlet pipe, and the other end of the bypass pipe is communicated with the annular cavity.

[0012] Furthermore, the flow rate of the gas in the bypass pipe is less than 1 / 10 of the total flow rate of the gas in the outlet pipe.

[0013] Preferably, a heat dissipation fan is installed at the condenser, an air duct and a blocking plug plate are installed at the outflow end of the heat dissipation fan, and a flexible plastic tube extending toward the evaporator is installed at the end of the air duct.

[0014] Furthermore, the blocking plug plate can be slidably installed on the outflow end of the heat dissipation fan, the flexible plastic tube is preferably a plastic corrugated tube, and other flexible tubes with plasticity can also be used; the heat dissipation fan is preferably a volute fan.

[0015] Preferably, it also includes a second unit with the same structure as the first unit; the first unit and the second unit serve as backup for each other.

[0016] Preferably, an airflow pipe is installed between the oil-gas separator and the condenser on the first unit and the second unit, a first electrically controlled valve is installed on the airflow pipe, and a connecting pipe is installed between the two airflow pipes, a second electrically controlled valve is installed on the connecting pipe.

[0017] Compared with the prior art, the present invention provides a twin-screw compressor unit, which has the following beneficial effects:

[0018] In the twin-screw compressor unit, the gaseous refrigerant after being vaporized and absorbing heat in the evaporator enters the hollow cavity in the female screw through the return air pipeline. The temperature of the female screw is high after working for a long time, and the low-temperature gaseous refrigerant absorbs heat when passing through the female screw, thereby increasing the temperature of the gaseous refrigerant. As the temperature at the female screw decreases, the maximum high temperature value inside the screw compressor body decreases. After the temperature and pressure of the gaseous refrigerant are worked by the warming and supercharger, the inlet pressure and inlet temperature of the gaseous refrigerant entering the screw compressor body are increased, and the internal maximum temperature difference of the screw compressor is reduced. The inlet pressure and density of the gaseous refrigerant entering the screw compressor body are increased, which can effectively improve the temperature balance inside the screw compressor body and the compression efficiency of the gaseous refrigerant; the female and male screws are heated evenly, effectively reducing the wear rate of both. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional structural schematic diagram of the present invention.

[0020] Figure 2 It is a schematic diagram of the top plan structure of the present invention.

[0021] Figure 3 It is a front view planar structure schematic diagram of the present invention.

[0022] Figure 4 The present invention Figure 2 Schematic diagram of the cross-sectional structure at AA in the middle.

[0023] Figure 5 It is a schematic diagram of the internal three-dimensional structure of the temperature increasing supercharger of the present invention.

[0024] Figure 6 It is a schematic diagram of the three-dimensional structure of the driving member of the present invention.

[0025] Figure 7 It is a schematic diagram of the internal cross-section stereoscopic structure of the Venturi jet tube of the present invention.

[0026] Figure 8 The present invention Figure 1 Schematic diagram of the local enlarged structure at point B in the middle.

[0027] Markings in the attached drawings: 1, evaporator; 2, oil-gas separator; 3, condenser; 4, throttling and pressure reduction assembly; 5, return air pipeline; 6, oil-gas pipeline; 7, shell; 8, male screw; 9, female screw; 10, drive motor; 11, return oil pump; 12, return oil pipeline; 13, mounting shell; 14, air inlet cylinder; 15, air outlet cylinder; 16, connecting pipeline; 17, first piston; 18, second piston; 19, air inlet pipe; 20, first one-way valve; 21, second one-way valve; 22, air outlet pipe; 23, drive shaft; 24. First eccentric cam; 25. First connecting shaft; 26. Second eccentric cam; 27. Second connecting shaft; 28. Right-angle connecting plate; 29. ​​First driving handle; 30. Second driving handle; 31. Bypass pipe; 32. Venturi jet pipe; 33. Annular cavity; 34. Air inlet hole; 35. Cooling fan; 36. Air duct; 37. Sealing plug plate; 38. Flexible plastic tube; 39. First unit; 40. Air flow pipe; 41. First electric control valve; 42. Series pipe; 43. Second electric control valve; 44. Second unit. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0029] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0031] Example 1

[0032] Please refer to Figure 1-4 A twin-screw compressor unit includes a first unit 39, a second unit 44 and an evaporator 1, wherein the first unit 39 is connected to the gas outlet of the evaporator 1. The first unit 39 and the second unit 44 have the same structure, and the first unit 39 and the second unit 44 are standby for each other. The first unit 39 and the second unit 44 are switched and controlled by necessary switching valves, etc., which will not be further described here.

[0033] The following description will be made by taking the first unit 39 as an example. The first unit 39 includes a screw compressor body, an oil-gas separator 2, a condenser 3 and a throttling and pressure reduction assembly 4 which are connected in sequence; the first unit 39 also includes a return air pipeline 5, a warming and supercharging device, an oil-gas pipeline 6 and an oil return assembly. The screw compressor body includes a shell 7, a male screw 8 rotatably installed in the shell 7, a female screw 9 rotatably installed in the shell 7 and meshing with the male screw 8, and a drive motor 10 that provides power for the rotation of the male screw 8. A hollow cavity is provided inside the female screw 9. One end of the return air pipeline 5 is connected to the air outlet end on the evaporator 1, and the other end of the return air pipeline 5 is connected to the air inlet end of the warming and supercharging device. The air outlet end of the warming and supercharging device is connected to the air inlet on the shell 7. One end of the oil-gas pipeline 6 is connected to the air outlet on the shell 7. The other end of the air pipeline 6 is connected to the air inlet on the oil-gas separator 2. The oil return assembly includes an oil return pump 11 and an oil return pipeline 12. The input end of the oil return pump 11 extends to the bottom of the oil-gas separator 2, and the output end of the oil return pump 11 is connected to the input end of the oil return pipeline 12. The output end of the oil return pipeline 12 extends from the upper part of the shell 7 into the shell 7; the warming and boosting device is used to heat and pressurize the low-temperature and low-pressure gaseous refrigerant refluxed from the evaporator 1; further, the warming and boosting device can use an electric auxiliary heating vacuum pump for pressurization and heating.

[0034] An airflow pipe 40 is installed between the oil-gas separator 2 and the condenser 3 on the first unit 39 and the second unit 44 , and a first electrically controlled valve 41 is installed on the airflow pipe 40 . A series pipe 42 is installed between the two airflow pipes 40 , and a second electrically controlled valve 43 is installed on the series pipe 42 .

[0035] The first unit 39 and the second unit 44 serve as backup for each other. When one of the units fails, the other unit can be started to avoid shutdown of the twin-screw compressor unit, effectively reducing the accident rate of the evaporator 1 not cooling due to shutdown; when the ambient temperature is high or the environment needs to be cooled quickly, the second electrically controlled valve 43 on the series pipe 42 can be opened, and the first electrically controlled valve 41 on the first unit 39 or the second unit 44 can be opened to allow the pressurized gaseous refrigerant to enter the same condenser 3, that is, to achieve parallel use of two groups of screw compressor bodies, further improve the liquefaction efficiency of the gaseous refrigerant in the condenser 3, accelerate the circulation of the refrigerant in the entire system, so as to achieve rapid cooling of the environment and improve the applicability of the twin-screw compressor unit to different working conditions; it should be noted that during the adjustment process, the refrigerant flow and pressure passing through the throttling and pressure reducing component 4 should be adaptively adjusted.

[0036] In the twin-screw compressor unit provided in the present embodiment, during the process of driving the male screw 8 driven by the driving motor 10 to rotate, the male screw 8 drives the driving shaft 23 and the driving member to rotate synchronously, and after being driven by the second eccentric cam 26, the second connecting shaft 27 and the second driving handle 30, the first piston 17 moves downward along the inner wall of the air inlet cylinder 14, and after being driven by the first eccentric cam 24, the first connecting shaft 25 and the first driving handle 29, the second piston 18 feeds along the inner wall of the air outlet cylinder 15 away from the mounting shell 13. At this time, the air pressure in the air inlet cylinder 14 and the connecting pipe 16 decreases, and the pressure in the air outlet cylinder 15 increases, the first one-way valve 20 opens, and the second one-way valve 21 closes, and the gaseous refrigerant is sucked into the air through the air inlet pipe 19. In the air intake cylinder 14; with the rotation of the drive shaft 23, after being driven by the second eccentric cam 26, the second connecting shaft 27 and the second driving handle 30, the first piston 17 moves up along the inner wall of the air intake cylinder 14, and after being driven by the first eccentric cam 24, the first connecting shaft 25 and the first driving handle 29, the second piston 18 feeds along the inner wall of the air outlet cylinder 15 toward the side close to the mounting shell 13. At this time, the air pressure in the air intake cylinder 14 and the connecting pipe 16 increases, and the pressure in the air outlet cylinder 15 decreases, the first one-way valve 20 is closed, and the second one-way valve 21 is opened, and the gaseous refrigerant is pressed into the air outlet cylinder 15 through the connecting pipe 16 and discharged through the air outlet pipe 22, and this reciprocating process is used to continuously pressurize and work the gaseous refrigerant.

[0037] The reflux speed of the gaseous refrigerant in the return air pipeline 5 to the warming and boosting device can be increased to avoid the accumulation of the gaseous refrigerant after absorbing heat in the condenser 3, thereby ensuring that the condenser 3 is in a low-pressure state, which is beneficial to the gasification of the liquid refrigerant in the condenser 3 and improving the refrigeration effect of the condenser 3; the gaseous refrigerant is compressed in the air inlet tube 14 and the connecting pipe 16, and is compressed in the air outlet tube 15. Under the continuous pressurization, the volume of the gaseous refrigerant decreases, and the density and temperature increase; the gaseous refrigerant is continuously compressed in three stages by the screw compressor body and the warming and boosting device; the warming and boosting device and the screw compressor body are started and stopped synchronously, and continuous three-stage compression of the gaseous refrigerant can be achieved without the need for external drive to do additional work, which can greatly improve the compression efficiency of the gaseous refrigerant, effectively shorten the liquefaction time of the gaseous refrigerant in the condenser 3, and significantly enhance the efficiency of the entire first unit 39.

[0038] Please refer to Figure 5The temperature increasing supercharger comprises a mounting shell 13, an air inlet cylinder 14 fixedly mounted on the mounting shell 13, an air outlet cylinder 15 fixedly mounted on the mounting shell 13 and arranged vertically offset with the air inlet cylinder 14, a connecting pipe 16 with two ends communicating with the inside of the air inlet cylinder 14 and the air outlet cylinder 15 respectively, a first piston 17 slidably mounted in the air inlet cylinder 14, a second piston 18 slidably mounted in the air outlet cylinder 15 and a driving member for driving the first piston 17 and the second piston 18 to slide, and an air inlet pipe 19 communicating with the inside of the air inlet cylinder 14 is provided on the air inlet cylinder 14. A first one-way valve 20 is installed in the air intake pipe 19, which allows gas to enter the air intake cylinder 14 in one direction. The output end of the return air pipeline 5 is connected with the input end of the air intake pipe 19. A second one-way valve 21 is provided at the connection between the connecting pipe 16 and the air outlet cylinder 15, which allows gas in the connecting pipe 16 to enter the air outlet cylinder 15 in one direction. The air outlet cylinder 15 is provided with an air outlet pipe 22 connected with the air intake end of the shell 7. The driving member can adopt two driving cylinders, which are fixedly installed in the mounting shell 13, and the first piston 17 and the second piston 18 are driven respectively by the two driving cylinders.

[0039] Please refer to Figure 6 A driving shaft 23 is rotatably mounted on the mounting shell 13, and the driving member includes a first eccentric cam 24 fixedly connected to the driving shaft 23, a first connecting shaft 25 fixedly mounted on the first eccentric cam 24 and away from the central axis of the driving shaft 23, a second eccentric cam 26 rotatably mounted on the inner wall of the mounting shell 13, a second connecting shaft 27 fixedly mounted on the second eccentric cam 26 and away from the central axis of the driving shaft 23, a right-angle connecting plate 28, a first driving handle 29 and a second driving handle 30. The first eccentric cam 24 and the second eccentric cam 26 are arranged vertically, the first connecting shaft 25 and the second connecting shaft 27 are fixedly connected by the right-angle connecting plate 28, one end of the first driving handle 29 is rotatably connected to the first connecting shaft 25, the other end of the first driving handle 29 is rotatably connected to the second piston 18, one end of the second driving handle 30 is rotatably connected to the second connecting shaft 27, the other end of the second driving handle 30 is rotatably connected to the first piston 17, and the driving shaft 23 is transmission-connected to the male screw 8; further, the driving shaft 23 is fixedly connected to the male screw 8.

[0040] Example 2

[0041] The twin-screw compressor unit provided in Example 1 is further optimized, specifically, as follows: Figure 7-8As shown, it also includes a bypass pipe 31, a Venturi jet tube 32 is installed on the return oil pipeline 12, an annular cavity 33 is provided on the Venturi jet tube 32, and a plurality of air inlet holes 34 communicating with the annular cavity 33 are provided at the neck of the Venturi jet tube 32. One end of the bypass pipe 31 is communicated with the outlet pipe 22, and the other end of the bypass pipe 31 is communicated with the annular cavity 33. Furthermore, the flow rate of the gas in the bypass pipe 31 is less than 1 / 10 of the total flow rate of the gas in the outlet pipe 22, so as to ensure that the air intake of the screw compressor body is sufficient. More specifically, a flow valve is installed at the bypass pipe 31 to adaptively adjust the flow rate of the gaseous refrigerant flowing through the bypass pipe 31.

[0042] In the twin-screw compressor unit provided in the present embodiment, part of the gaseous refrigerant treated by the warming and supercharging device enters the annular cavity 33 in the venturi jet tube 32 through the bypass pipe 31. When the cooling lubricating oil flows through the neck of the venturi jet tube 32, the pressure at the air inlet is reduced, and the gaseous refrigerant enters the venturi jet tube 32 through each air inlet hole 34 and contacts with the cooling lubricating oil in a high-temperature state. Since the temperature of the gaseous refrigerant is much lower than the temperature of the cooling lubricating oil, the cooling lubricating oil is cooled under the action of the low-temperature gaseous refrigerant, thereby reducing the oil temperature of the cooling lubricating oil entering the screw compressor body. The cooling lubricating oil that becomes mist due to the air pressure difference is sprayed into the compression chamber of the screw compressor body, so as to compress the gaseous refrigerant, reduce the temperature in the compression chamber, and seal and lubricate the female and male screws, thereby effectively reducing the extreme high temperature value in the screw compressor body, reducing the temperature difference change rate of the screw compressor body, and playing a positive effect on reducing the wear rate of the female and male screws.

[0043] Example 3

[0044] The twin-screw compressor unit provided in Example 2 is further optimized, specifically, as follows: Figure 1-3 As shown, a heat dissipation fan 35 is installed at the condenser 3, and an air duct 36 and a sealing plug plate 37 are installed at the outlet end of the heat dissipation fan 35, and a flexible plastic tube 38 extending toward the evaporator 1 is installed at the end of the air duct 36; further, the sealing plug plate 37 can be slidably installed on the outlet end of the heat dissipation fan 35, and the flexible plastic tube 38 is preferably a plastic corrugated tube, and other flexible tubes with plasticity can also be used; the heat dissipation fan 35 is preferably a volute fan.

[0045] The twin-screw compressor unit provided in the present embodiment can accelerate the heat dissipation at the condenser 3 through the heat dissipation fan 35; when the unit has been used for a period of time, ice will appear on the outer wall of the evaporator 1 due to the low temperature, and manual ice removal is relatively laborious; the unit can be shut down, the outlet end of the heat dissipation fan 35 is blocked by the blocking plug plate 37, and the heat dissipation fan 35 is started. The heat dissipation fan 35 transports the residual heat at the condenser 3 to the evaporator 1 through the induced draft duct 36 and the flexible plastic tube 38. By moving the outlet port position of the flexible plastic tube 38, the ice at various places of the evaporator 1 can be comprehensively processed. The ice on the evaporator 1 is quickly dissolved under the action of the high-temperature airflow. While cooling the condenser 3, the residual heat at the condenser 3 is used to clean the ice on the evaporator 1, which is more energy-saving and environmentally friendly, and effectively improves the efficiency and effect of ice cleaning at the evaporator 1.

[0046] The use process of the twin-screw compressor unit provided by the present invention is as follows: the evaporator 1 is installed in the environment to be cooled, and the gaseous refrigerant after the secondary heating and pressurization is compressed by the screw compressor body to increase the temperature and pressure of the gaseous refrigerant. Under the action of continuous pressurization, the cooling lubricating oil and the gaseous refrigerant enter the oil-gas separator 2 together, and the oil and gas are separated by the oil-gas separator 2. The return oil pump 11 re-injects the cooling lubricating oil in the oil-gas separator 2 into the shell 7 of the screw compressor body through the return oil pipeline 12, and the high-temperature and high-pressure refrigerant enters the condenser 3. As the pressure in the condenser 3 gradually increases, the gaseous refrigerant is converted into liquid to refrigerate and release a large amount of heat. The liquid refrigerant enters the evaporator 1 after the flow and pressure are adjusted by the throttling and pressure reducing component 4. At this time, the pressure in the evaporator 1 is low, and the liquid refrigerant quickly vaporizes and absorbs heat to form a gaseous refrigerant in a low-temperature and low-pressure state. The environment is cooled by the evaporator 1, and the gaseous refrigerant in a low-temperature and low-pressure state flows back to the shell 7 on the screw compressor body through the return air pipeline 5, the hollow cavity inside the screw and the warming supercharger; in this way, the twin-screw compressor unit achieves cooling of the environment.

[0047] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A twin-screw compressor unit, characterized in that: The invention comprises a first machine unit (39) and an evaporator (1), wherein the first machine unit (39) comprises a screw compressor body, an oil-gas separator (2), a condenser (3) and a throttling and pressure reduction assembly (4) which are connected in sequence; the first machine unit (39) further comprises a return air pipeline (5), a temperature increasing and pressure increasing device, an oil-gas pipeline (6) and an oil return assembly; The screw compressor body comprises a shell (7), a male screw (8) rotatably mounted in the shell (7), a female screw (9) rotatably mounted in the shell (7) and meshing with the male screw (8), and a driving motor (10) for providing power for the rotation of the male screw (8); a hollow cavity is provided inside the female screw (9); one end of the return air pipeline (5) is connected to the air outlet end of the evaporator (1); the other end of the return air pipeline (5) is connected to the air inlet end of the warming supercharger; the air outlet end of the warming supercharger is connected to the air inlet port of the shell (7); one end of the oil-gas pipeline (6) is connected to the air outlet port of the shell (7); the other end of the oil-gas pipeline (6) is connected to the air inlet port of the oil-gas separator (2); The oil return assembly comprises an oil return pump (11) and an oil return pipeline (12); the input end of the oil return pump (11) extends into the bottom of the oil-gas separator (2); the output end of the oil return pump (11) is connected to the input end of the oil return pipeline (12); the output end of the oil return pipeline (12) extends from the upper part of the shell (7) into the shell (7); the temperature increase and pressure increaser is used to increase the temperature and pressure of the low-temperature and low-pressure gaseous refrigerant returning from the evaporator (1); The temperature increasing supercharger comprises a mounting shell (13), an air inlet cylinder (14) fixedly mounted on the mounting shell (13), an air outlet cylinder (15) fixedly mounted on the mounting shell (13) and arranged vertically offset with the air inlet cylinder (14), a connecting pipe (16) with two ends respectively communicating with the inside of the air inlet cylinder (14) and the air outlet cylinder (15), a first piston (17) slidably mounted in the air inlet cylinder (14), a second piston (18) slidably mounted in the air outlet cylinder (15), and a driving member for driving the first piston (17) and the second piston (18) to slide, wherein the air inlet cylinder (14) is provided with a first piston (17) and a second piston (18) to slide. The cylinder (14) is provided with an air intake pipe (19) which is in communication with the interior of the air intake cylinder (14); a first one-way valve (20) is installed in the air intake pipe (19) to allow gas to enter the air intake cylinder (14) in one direction; the output end of the return air pipeline (5) is in communication with the input end of the air intake pipe (19); a second one-way valve (21) is provided at the connection point between the connecting pipe (16) and the air outlet cylinder (15) to allow gas in the connecting pipe (16) to enter the air outlet cylinder (15) in one direction; and an air outlet pipe (22) is provided at the air outlet cylinder (15) to be in communication with the air intake end of the housing (7); A drive shaft (23) is rotatably mounted on the mounting shell (13), and the drive member comprises a first eccentric cam (24) fixedly connected to the drive shaft (23), a first connecting shaft (25) fixedly mounted on the first eccentric cam (24) and away from the central axis of the drive shaft (23), a second eccentric cam (26) rotatably mounted on the inner wall of the mounting shell (13), a second connecting shaft (27) fixedly mounted on the second eccentric cam (26) and away from the central axis of the drive shaft (23), a right-angle connecting plate (28), a first drive handle (29), and a second drive handle ( 30), the first eccentric cam (24) and the second eccentric cam (26) are arranged vertically, the first connecting shaft (25) and the second connecting shaft (27) are fixedly connected via a right-angle connecting plate (28), one end of the first driving handle (29) is rotatably connected to the first connecting shaft (25), the other end of the first driving handle (29) is rotatably connected to the second piston (18), one end of the second driving handle (30) is rotatably connected to the second connecting shaft (27), the other end of the second driving handle (30) is rotatably connected to the first piston (17), and the driving shaft (23) is drivingly connected to the male screw (8).

2. A twin-screw compressor unit according to claim 1, characterized in that: It also comprises a bypass pipe (31), a Venturi jet pipe (32) being installed on the oil return pipeline (12), an annular cavity (33) being provided on the Venturi jet pipe (32), a plurality of air inlet holes (34) being provided at the neck of the Venturi jet pipe (32) and being communicated with the annular cavity (33), one end of the bypass pipe (31) being communicated with the air outlet pipe (22), and the other end of the bypass pipe (31) being communicated with the annular cavity (33).

3. A twin-screw compressor unit according to claim 1, characterized in that: The condenser (3) is provided with a heat dissipation fan (35), an air induction pipe (36) and a blocking plug plate (37) are provided at the outlet end of the heat dissipation fan (35), and a flexible plastic tube (38) extending towards the evaporator (1) is provided at the end of the air induction pipe (36).

4. A twin-screw compressor unit according to claim 1, characterized in that: It also includes a second unit (44) having the same structure as the first unit (39); the first unit (39) and the second unit (44) serve as backup for each other.

5. A twin-screw compressor unit according to claim 4, characterized in that: An airflow pipe (40) is installed between the oil-gas separator (2) and the condenser (3) on the first unit (39) and the second unit (44), a first electrically controlled valve (41) is installed on the airflow pipe (40), a series connection pipe (42) is installed between the two airflow pipes (40), and a second electrically controlled valve (43) is installed on the series connection pipe (42).

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