CN221824059U - A medium pressure controllable single-unit two-stage screw compressor - Google Patents

Abstract

The utility model relates to the field of compressors, and in particular to a medium-pressure controllable single-machine two-stage screw compressor. The compressor includes a low-pressure compression mechanism and a high-pressure compression mechanism arranged at both ends of the compressor, the low-pressure compression mechanism includes a pair of low-pressure rotors meshing with each other, and the high-pressure compression mechanism includes a pair of high-pressure rotors meshing with each other; the low-pressure compression mechanism is connected to a low-pressure motor for driving the low-pressure rotor to rotate, and the high-pressure compression mechanism is connected to a high-pressure motor for driving the high-pressure rotor to rotate; the low-pressure motor and the high-pressure motor are arranged in the middle of the compressor, and the low-pressure compression mechanism, the low-pressure motor, the high-pressure motor and the high-pressure compression mechanism are connected in sequence; wherein the low-pressure motor and the high-pressure motor both adopt variable-frequency synchronous permanent magnet motors. By adopting a dual variable-frequency motor, the medium pressure can be returned to the optimal pressure according to the change in speed, thereby improving the operating efficiency.

Description

A medium pressure controllable single-unit two-stage screw compressor

Technical Field

The utility model relates to the field of compressors, in particular to a single-machine two-stage screw compressor with controllable medium pressure.

Background Art

Screw compressors are divided into single-stage and multi-stage compression structures according to different compression characteristics, and the two-stage compression structure is the most common among the multi-stage compression structures.

Most screw compressors used in the refrigeration industry have to deal with high pressure ratio conditions. The lower the evaporation temperature, the higher the pressure ratio, the greater the pressure ratio and pressure difference between the unit volumes of the single-stage screw compressor, the greater the internal leakage, and the lower the volumetric efficiency. The lower the evaporation pressure, the greater the power consumption of the refrigeration capacity, the lower the COP value of the system, the less compression occurs, the higher the noise, and the higher the exhaust temperature.

Two-stage compressors are completed by two compressions from low pressure to high pressure. Such gas transmission coefficient is higher than that of single compressors. At the same time, the pressure ratio of each stage is reduced, and the exhaust temperature is relatively low, which is suitable for working under large pressure ratio conditions. However, the inter-stage pressure of most single-stage two-stage screw compressors on the market is uncontrollable, resulting in the inter-stage pressure not being the optimal operating pressure after the economizer inter-stage air replenishment, which ultimately leads to poor compressor performance.

Utility Model Content

In order to solve the above technical problems, the purpose of the utility model is to provide a single-machine two-stage screw compressor with controllable medium pressure. By adopting a dual-frequency motor, the medium pressure can be returned to the optimal pressure according to the change of the speed, thereby improving the operating efficiency.

In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

A medium-pressure controllable single-unit two-stage screw compressor, the compressor comprising:

A low-pressure stage compression mechanism is arranged at one end of the compressor and a high-pressure stage compression mechanism is arranged at the other end of the compressor, the low-pressure stage compression mechanism includes a pair of low-pressure stage rotors meshing with each other, and the high-pressure stage compression mechanism includes a pair of high-pressure stage rotors meshing with each other; a low-pressure stage motor for driving the low-pressure stage rotor to rotate is connected to the low-pressure stage compression mechanism, and a high-pressure stage motor for driving the high-pressure stage rotor to rotate is connected to the high-pressure stage compression mechanism; the low-pressure stage motor and the high-pressure stage motor are arranged in the middle of the compressor, and the low-pressure stage compression mechanism, the low-pressure stage motor, the high-pressure stage motor and the high-pressure stage compression mechanism are connected in sequence, so that the airflow formed after compression by the low-pressure stage compression mechanism passes through the low-pressure stage motor and the high-pressure stage motor in sequence, and the airflow serves as the air source on the suction side of the high-pressure stage compression mechanism;

The low-voltage motor and the high-voltage motor both adopt variable-frequency synchronous permanent magnet motors.

Preferably, the low-voltage motor comprises: a low-voltage motor housing, a low-voltage motor stator fixedly arranged inside the low-voltage motor housing, and a low-voltage motor rotor rotatably arranged inside the low-voltage motor stator; a plurality of low-voltage heat dissipation channels evenly distributed around the circumferential direction are formed between the outer circumferential surface of the low-voltage motor stator and the inner wall of the low-voltage motor housing, and the low-voltage heat dissipation channels connect the two axial ends of the low-voltage motor stator; the low-voltage motor rotor is connected to one of the low-voltage rotors and drives it to rotate.

Preferably, a first-stage motor liquid spray hole is provided on the low-voltage stage motor.

Preferably, the high-voltage motor comprises: a high-voltage motor housing, a high-voltage motor stator fixedly arranged inside the high-voltage motor housing, and a high-voltage motor rotor rotatably arranged inside the high-voltage motor stator; a plurality of high-voltage heat dissipation channels evenly distributed around the circumferential direction are formed between the outer peripheral surface of the high-voltage motor stator and the inner wall of the high-voltage motor housing, and the high-voltage heat dissipation channels connect the two axial ends of the high-voltage motor stator; the high-voltage motor rotor is connected to one of the high-voltage rotors and drives it to rotate.

Preferably, a secondary motor spray hole is provided on the high-voltage motor.

In summary, the advantages of the utility model are as follows:

By setting variable frequency low-voltage motors and high-voltage motors, the speed of the low-voltage motors and high-voltage motors can be adjusted to adjust the size of the intermediate pressure, so that the change in speed can make the medium pressure return to the optimal pressure and improve operating efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of the single-unit two-stage screw compressor;

FIG2 is a schematic cross-sectional view of the single-unit two-stage screw compressor;

Figure numerals: 1. low-pressure stage compression mechanism; 2. high-pressure stage compression mechanism; 11. low-pressure stage rotor; 12. low-pressure stage motor; 13. low-pressure stage motor housing; 14. low-pressure stage motor stator; 15. low-pressure stage motor rotor; 16. low-pressure stage heat dissipation channel; 17. first-stage motor spray hole; 21. high-pressure stage rotor; 22. high-pressure stage motor; 23. high-pressure stage motor housing; 24. high-pressure stage motor stator; 25. high-pressure stage motor rotor; 26. high-pressure stage heat dissipation channel; 27. second-stage motor spray hole.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

It should also 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, it does not require further definition and explanation in subsequent drawings.

The specific implementation of the utility model is described in detail below in conjunction with the accompanying drawings.

As shown in Figures 1 and 2, a single-unit two-stage screw compressor comprises: a low-pressure stage compression mechanism 1 arranged at the left end of the compressor and a high-pressure stage compression mechanism 2 arranged at the right end of the compressor, a low-pressure stage motor 12 is connected to the low-pressure stage compression mechanism 1, and a high-pressure stage motor 22 is connected to the high-pressure stage compression mechanism 2, the low-pressure stage motor 12 and the high-pressure stage motor 22 are arranged in the middle of the compressor, and the low-pressure stage compression mechanism 1, the low-pressure stage motor 12, the high-pressure stage motor 22 and the high-pressure stage compression mechanism 2 are connected in sequence. When the compressor is working, air enters from the low-pressure stage compression mechanism 1 and is compressed by the low-pressure stage compression mechanism 1, and then the compressed air flows to the right and passes through the low-pressure stage motor 12 and the high-pressure stage motor 22 in sequence, cooling the low-pressure stage motor 12 and the high-pressure stage motor 22, and then the compressed air enters the high-pressure stage compression mechanism 2 as the air source on the suction side of the high-pressure stage compression mechanism 2, and is discharged from the right end of the compressor after being compressed by the high-pressure stage compression mechanism 2.

As shown in Figure 2, the low-pressure stage compression mechanism 1 includes: a low-pressure stage shell, two low-pressure stage rotors 11 (a low-pressure stage male rotor and a low-pressure stage female rotor) arranged inside the low-pressure stage shell and meshing with each other, and a low-pressure stage bearing seat arranged at the right end of the low-pressure stage shell, the left end of the low-pressure stage rotor 11 is supported by a support seat inside the low-pressure stage shell, the right end of the low-pressure stage rotor 11 is supported by the low-pressure stage bearing seat, and the right end of one of the low-pressure stage rotors 11 extends to the right to the right side of the low-pressure stage bearing seat.

As shown in Figure 2, a low-pressure motor 12 is arranged at the right end of the low-pressure bearing seat, and the right end of the low-pressure male rotor extends into the low-pressure motor 12. The low-pressure motor 12 is used to drive the low-pressure male rotor to rotate, thereby realizing the air compression process of the low-pressure compression mechanism 1.

Specifically, the low-voltage motor 12 includes: a low-voltage motor housing 13, a low-voltage motor stator 14 fixedly arranged inside the low-voltage motor housing 13, and a low-voltage motor rotor 15 rotatably arranged inside the low-voltage motor stator 14. A plurality of low-voltage heat dissipation channels 16 uniformly distributed around the circumferential direction are formed between the outer circumferential surface of the low-voltage motor stator 14 and the inner wall of the low-voltage motor housing 13, and the low-voltage heat dissipation channels 16 are connected to the two axial ends of the low-voltage motor stator 14, and the low-voltage motor rotor 15 is connected to the low-voltage positive rotor and drives the low-voltage positive rotor to rotate.

As shown in Figure 2, the high-pressure stage compression mechanism 2 includes: a high-pressure stage shell, two high-pressure stage rotors 21 (a high-pressure stage male rotor and a high-pressure stage female rotor) arranged inside the high-pressure stage shell and meshing with each other, and a high-pressure stage bearing seat arranged at the right end of the high-pressure stage shell, the left ends of the high-pressure stage male rotor and the high-pressure stage female rotor are supported by the support seat inside the high-pressure stage shell, and the right ends of the high-pressure stage male rotor and the high-pressure stage female rotor are supported by the high-pressure stage bearing seat.

As shown in Figure 2, a high-pressure stage motor 22 is arranged at the left end of the high-pressure stage housing, and the left end of the high-pressure stage male rotor extends into the high-pressure stage motor 22. The high-pressure stage motor 22 is used to drive the high-pressure stage male rotor to rotate, thereby realizing the air compression process of the high-pressure stage compression mechanism 2.

Specifically, the high-voltage motor 22 includes: a high-voltage motor housing 23 (in this embodiment, the high-voltage motor housing 23 and the high-voltage housing are the same component), a high-voltage motor stator 24 fixedly arranged inside the high-voltage motor housing 23, and a high-voltage motor rotor 25 rotatably arranged in the high-voltage motor stator 24. A plurality of high-voltage heat dissipation channels 26 evenly distributed around the circumferential direction are formed between the outer peripheral surface of the high-voltage motor stator 24 and the inner wall of the high-voltage motor housing 23. The high-voltage heat dissipation channels 26 connect the two axial ends of the high-voltage motor stator 24. The high-voltage motor rotor 25 is connected to the high-voltage positive rotor and drives the high-voltage positive rotor to rotate.

In addition, as shown in FIG. 2 , a primary motor spray hole 17 and a secondary motor spray hole 27 are respectively provided on the low-voltage motor 12 and the high-voltage motor 22 for spraying oil to cool the motors.

In the above-mentioned single-unit two-stage screw compressor, both the low-pressure stage motor 12 and the high-pressure stage motor 22 adopt variable frequency synchronous permanent magnet motors, which can return the medium pressure to the optimal pressure by changing the speed, thereby improving the operating efficiency. The compressor is completed by two compressions from low pressure to high pressure, and the gas transmission coefficient is higher than that of a single-unit compressor; at the same time, the pressure ratio of each stage is reduced, and the exhaust temperature is relatively low, which is suitable for working under large pressure ratio conditions.

The above is a description of the embodiments of the utility model. Through the above description of the disclosed embodiments, professionals and technicians in the field can implement or use the utility model. Various modifications to these embodiments will be obvious to professionals and technicians in the field. The general principles defined in this article can be implemented in other embodiments without departing from the spirit or scope of the utility model. Therefore, the utility model will not be limited to these embodiments shown in this article, but will conform to the widest range consistent with the principles and novelties disclosed in this article.

Claims (5)

1. A single-stage, medium pressure controllable, two-stage screw compressor, the compressor comprising:

The low-pressure stage compression mechanism (1) is arranged at one end of the compressor, the high-pressure stage compression mechanism (2) is arranged at the other end of the compressor, the low-pressure stage compression mechanism (1) comprises a pair of intermeshing low-pressure stage rotors (11), and the high-pressure stage compression mechanism (2) comprises a pair of intermeshing high-pressure stage rotors (21); the low-pressure stage compression mechanism (1) is connected with a low-pressure stage motor (12) for driving the low-pressure stage rotor (11) to rotate, and the high-pressure stage compression mechanism (2) is connected with a high-pressure stage motor (22) for driving the high-pressure stage rotor (21) to rotate; the low-pressure stage motor (12) and the high-pressure stage motor (22) are arranged in the middle of the compressor, and the low-pressure stage compression mechanism (1), the low-pressure stage motor (12), the high-pressure stage motor (22) and the high-pressure stage compression mechanism (2) are sequentially communicated, so that air flow formed after the compression of the low-pressure stage compression mechanism (1) sequentially passes through the low-pressure stage motor (12) and the high-pressure stage motor (22), and the air flow is used as an air source at the suction side of the high-pressure stage compression mechanism (2);

the motor is characterized in that the low-voltage motor (12) and the high-voltage motor (22) are both frequency-conversion synchronous permanent magnet motors.

2. A single-machine, two-stage screw compressor with controllable medium pressure according to claim 1, characterized in that the low-pressure stage motor (12) comprises: a low-voltage motor housing (13), a low-voltage motor stator (14) fixedly arranged inside the low-voltage motor housing (13), and a low-voltage motor rotor (15) rotatably arranged inside the low-voltage motor stator (14); a plurality of low-pressure-level heat dissipation channels (16) which are uniformly distributed around the circumferential direction are formed between the outer peripheral surface of the low-pressure-level motor stator (14) and the inner wall of the low-pressure-level motor shell (13), and the low-pressure-level heat dissipation channels (16) are communicated with two axial ends of the low-pressure-level motor stator (14); the low-voltage stage motor rotor (15) is connected with one of the low-voltage stage rotors (11) and drives the low-voltage stage motor rotor to rotate.

3. A single-machine twin-screw compressor with controllable medium pressure according to claim 2, characterized in that the low-pressure motor (12) is provided with a primary motor liquid spraying hole (17).

4. A single-machine, two-stage screw compressor with controllable medium pressure according to claim 1, characterized in that the high-pressure stage motor (22) comprises: a high-voltage motor housing (23), a high-voltage motor stator (24) fixedly arranged inside the high-voltage motor housing (23), and a high-voltage motor rotor (25) rotatably arranged inside the high-voltage motor stator (24); a plurality of high-pressure-level heat dissipation channels (26) which are uniformly distributed around the circumferential direction are formed between the outer peripheral surface of the high-pressure-level motor stator (24) and the inner wall of the high-pressure-level motor shell (23), and the high-pressure-level heat dissipation channels (26) are communicated with two axial ends of the high-pressure-level motor stator (24); the high-voltage-stage motor rotor (25) is connected with one of the high-voltage-stage rotors (21) and drives the same to rotate.

5. A single-machine twin-screw compressor with controllable medium pressure according to claim 4, characterized in that the high-pressure motor (22) is provided with a secondary motor liquid spraying hole (27).