Semi-closed double-screw compressor device and compressor system

Abstract

The utility model relates to the field of compressors, in particular to a semi-closed double-screw compressor device and a compressor system.The semi-closed double-screw compressor device comprises a motor arranged in an inner cavity of the front portion of a compressor shell and a compressor body arranged in an inner cavity of the rear portion of the compressor shell, a compressor air inlet is formed in the position, between the motor and the compressor body, of the compressor shell and communicates with a compression chamber of the compressor through a compressor air inlet channel formed between the motor and the compressor body. And the compressor shell and the motor are provided with motor cooling structures which are matched with each other and are communicated with the compression chamber. According to the compressor, on the premise that the air suction efficiency of the compressor is guaranteed, efficient cooling of the motor is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to compressor field, concretely relates to a kind of semi-closed double screw compressor device and compressor system. BACKGROUND

[0002] Compressor is the important component equipment of refrigeration, heat pump system, and the performance of compressor directly influences the efficiency and power consumption of system.Semi-closed screw compressor is a typical volumetric compressor, and has irreplaceable effect.Semi-closed screw compressor combines compressor body and motor and installs in compressor shell, and this structure makes compressor maintain high sealing property, and can stably and continuously carry out gas compression, to greatly improve compression efficiency.In the design of semi-closed screw compressor, the design of gas inlet and gas inlet passage is particularly important.Reasonable gas inlet design and optimized gas inlet passage can ensure that gas flows into compressor smoothly, reduce airflow resistance, and improve gas inlet efficiency.This not only can reduce the energy consumption of compressor, but also can prolong its service life.

[0003] Meanwhile, the arrangement of gas inlet also has important influence on compressor system pipeline arrangement.Reasonable gas inlet arrangement can reduce pipeline length and elbow quantity, reduce system resistance, so that the whole system is more efficient and stable.On the other hand, the motor of semi-closed screw compressor generates a large amount of heat when running at high speed, so effective cooling measures need to be taken.This is not only to protect the motor from overheating damage, but also to ensure that compressor can continuously and stably run.It is worth noting that the current economizer inlet flow of semi-closed screw compressor is small.This is mainly due to the limitation of rotor pitch, and the economizer inlet flow cannot be simply improved by increasing sectional area.This affects the efficiency of compressor to some extent, so that it has certain limitations in actual application.In addition, the existing screw compressor can usually only run in single system, and cannot quickly switch the system where compressor is located.This makes screw compressor not flexible enough in some occasions where the amount of refrigeration needs to be quickly adjusted.

[0004] The existing semi-hermetic screw compressor sets the gas inlet at the end of the compressor to take into account the heat dissipation of the motor and the gas inlet. After the refrigerant enters the compressor through the gas inlet, it first flows through the motor and carries away the heat generated by the operation of the motor, and then enters the compression chamber. After compression, it is discharged through the exhaust port. The flow channel of the refrigerant flowing through the motor mainly includes the flow channel set in the motor support space, the flow channel set in the stator cooling jacket, the gap between the stator and the rotor, and the flow channel set in the rotor. Among them, a large number of support structures set in the motor support space increase the flow resistance of the refrigerant. In order to improve the contact area between the refrigerant and the heat dissipation surface, a large number of complex flow channel structures are set in the motor stator cooling jacket, which increases the flow resistance of the refrigerant. In addition, in order to improve the performance and efficiency of the motor, the gap between the stator and the rotor is usually very narrow, allowing only a small amount of refrigerant to flow through. The flow channel in the rotor moves at high speed, and the refrigerant has a large resistance when flowing into and out of the flow channel. Therefore, the existing refrigerant inlet passage structure flowing through the motor will cause a large inlet resistance, affecting the inlet efficiency. In addition, due to the limitation of the design of the inlet passage and the inlet method of the existing semi-hermetic screw compressor, only a single gas inlet is set in a single direction, which reduces the flexibility of the compressor system design to some extent and increases the complexity and flow resistance of the external gas inlet pipeline.

[0005] In the aspect of motor cooling, during the operation of the semi-hermetic screw compressor, the motor will generate a large amount of heat, and the compressor will not be able to operate stably if the heat is not dissipated efficiently in time. How to balance the intake efficiency of the compressor, the cooling efficiency of the motor and the convenience of pipeline arrangement is the key to the design of the semi-hermetic screw compressor. At present, the motor cooling of the semi-hermetic screw compressor mainly includes the following several ways: refrigerant cooling, cooling liquid cooling, lubricating oil cooling and the like. Among them, the refrigerant cooling way makes the refrigerant flow through the refrigerant passages inside and outside the motor, and a large amount of heat generated during the operation of the motor is taken away by the flow of the refrigerant. This way does not need to add an external cooling circulation system, and to a certain extent, reduces the complexity of the system, but increases the refrigerant intake resistance and affects the suction efficiency of the compressor. The cooling liquid cooling is to set a cooling jacket outside the motor stator, and set an external heat dissipation circulation, and the heat generated during the operation of the motor is taken away by the flow of the cooling liquid in the cooling jacket. This way has good cooling effect and reduces the suction resistance of the compressor, but increases the complexity and operation and maintenance cost of the system. The lubricating oil cooling is to set lubricating oil passages in the motor stator and rotor, and the heat generated during the operation of the motor is taken away by the flow of the lubricating oil. This way does not need to add an external cooling circulation system and will not increase the suction resistance of the compressor, but this way needs a large amount of lubricating oil supply, and puts forward higher requirements for the oil pump and oil cooler, and increases the operation and maintenance cost of the system. In addition, at present, the motor cooling is often realized by combining multiple cooling methods, such as: setting a cooling jacket outside the motor stator to take away the heat generated by the stator through the cooling liquid, and opening refrigerant passages in the rotor to take away the heat generated by the rotor through the flow of the refrigerant. Therefore, how to balance the intake efficiency of the compressor, the cooling efficiency of the motor and the convenience of pipeline arrangement is the key to the design of the semi-hermetic screw compressor. Practical new type content

[0006] The utility model discloses a kind of semi-hermetic double-screw compressor device and compressor system, which is helpful to realize the efficient cooling of motor under the premise of guaranteeing the suction efficiency of compressor.

[0007] The technical scheme of the utility model is as follows: a kind of semi-hermetic double-screw compressor device, including the motor being arranged in the front inner cavity of compressor shell and the compressor body of the rear inner cavity of compressor shell, the rotor of motor is connected with compressor rotor, compressor intake is arranged between motor and compressor body on the compressor shell, the compressor intake is connected with the compression chamber of compressor by the compressor intake passage being arranged between motor and compressor body, motor cooling structure that is matched and communicates compression chamber is arranged on the compressor shell and motor.

[0008] Further, the motor cooling structure comprises a motor cooling air inlet arranged at the front end of the compressor shell, the motor is internally provided with a motor cooling channel, and the motor cooling channel is communicated with the compression chamber of the compressor through a motor cooling working medium channel arranged between the motor and the compressor body.

[0009] Further, the motor cooling channel comprises motor rotor cooling channels arranged at the rotor of the motor in a circumferential direction, and the rotor of the motor and the motor stator form a gap channel.

[0010] Further, a stator cooling sleeve is arranged outside the motor stator in the compressor shell, and the stator cooling sleeve is provided with a stator cooling channel.

[0011] Further, a cooling working medium inlet chamber is formed between the motor cooling air inlet and the motor in the compressor shell.

[0012] Further, a liquid collecting recess is arranged at the lower side of the compressor shell between the motor and the compressor body, and a liquid discharge port is arranged on the side wall of the liquid collecting recess.

[0013] Further, compressor air inlets are arranged at the upper left and right sides of the compressor shell between the motor and the compressor body, the compressor shell is further provided with a compressor air inlet liquid discharge port between the motor and the compressor body, and an exhaust port is arranged at the lower side of the rear end of the compressor shell.

[0014] Further, an economizer air inlet is arranged at the rear side of the compressor shell and communicated with the compression chamber.

[0015] A semi-enclosed double-screw compressor system comprises a semi-enclosed double-screw compressor device, the liquid discharge port is connected with the compressor air inlet liquid discharge port through a liquid discharge branch path, a liquid pump, and a post-pump liquid discharge branch path, a liquid external discharge path is arranged on the liquid discharge branch path and connected with a liquid discharge valve, the exhaust port is connected with the liquid pump through a high-pressure gas path, and an exhaust path connected with a system oil separator is arranged on the high-pressure gas path.

[0016] A semi-enclosed double-screw compressor system comprises a semi-enclosed double-screw compressor device, the liquid discharge port is connected with the compressor air inlet liquid discharge port through a liquid discharge branch path, a liquid pump, and a post-pump liquid discharge branch path, a liquid external discharge path is arranged on the liquid discharge branch path and connected with a liquid discharge valve, the exhaust port is connected with the liquid pump through a high-pressure gas path, and an exhaust path connected with a system oil separator is arranged on the high-pressure gas path.

[0017] Compared with the prior art, the utility model has the following advantages:

[0018] 1. Set compressor suction port between motor and compressor body, realize low pressure resistance suction, most refrigerant gas enters through compressor suction port when compressor is running, due to shorter flow channel and less intermediate protrusions, higher suction efficiency can be realized. Set motor cooling suction port in front of motor, part of refrigerant gas enters compressor through motor cooling suction port, heat generated in motor operation is taken away by refrigerant flowing through motor, so that high efficient heat dissipation and cooling of motor is realized under the premise of ensuring suction efficiency (low suction pressure loss) of compressor. Since compressor suction port is arranged in the middle of compressor, two compressor suction ports can be arranged in different directions, any suction port can be connected to system, or two suction ports can be connected to two different systems.

[0019] 2. Since refrigerant gas may become liquid due to condensation when flowing in semi-closed double screw compressor, in order to avoid liquid refrigerant affecting compression process after entering compression chamber, liquid collection recess is arranged at low position between motor and compressor body, so that liquid refrigerant is collected to liquid collection recess due to gravity, when liquid level reaches a certain height, liquid is discharged from compressor through liquid discharge port, avoiding liquid accumulation in compressor and affecting normal use of compressor.

[0020] 3. In addition, two economizer inlets are arranged on both sides of compression chamber of compressor, any economizer inlet can be connected to system economizer, two economizer inlets can be connected to single system economizer, or two economizer inlets are connected to two different system economizers. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a perspective view of the semi-closed double screw compressor device of the utility model;

[0022] Figure 2 It is a front view sectional view of the semi-closed double screw compressor device of the utility model;

[0023] Figure 3 It is a front view sectional view of the semi-closed double screw compressor device of the utility model;

[0024] Figure 4 It is a system diagram of a compressor system of the utility model;

[0025] Figure 5 It is a system diagram of another compressor system of the utility model;

[0026] In the figure: 10 - screw compressor; 20 - motor; 201 - motor stator; 202 - motor rotor; 203 - electrical box; 204 - motor cooling air inlet; 205 - stator cooling jacket; 206 - gap channel; 207 - motor rotor cooling channel; 208 - motor cooling working medium channel; 209 - liquid collecting recess; 210 - liquid discharge port; 211 - stator cooling channel; 212 - cooling working medium inlet chamber; 30 - compressor body; 301 - compressor shell; 302 - compressor rotor; 303 - left compressor air inlet; 304 - right compressor air inlet; 305 - compressor air inlet channel; 306 - air outlet; 307 - left economizer inlet; 308 - right economizer inlet; 309 - compression chamber; 310 - compressor air inlet liquid discharge port; 311 - bearing seat structure; 401 - liquid pump; 402 - liquid discharge valve; 501 - liquid discharge branch path; 502 - liquid discharge branch path after the pump; 503 - high-pressure gas path; 504 - exhaust gas path; 505 - liquid discharge path. DETAILED DESCRIPTION

[0027] In order to make the above features and advantages of the utility model more obvious, the following examples are given, and the detailed description is given as follows with reference to the drawings, but the utility model is not limited to this.

[0028] Reference Figures 1 to 5

[0029] A semi-closed double-screw compressor device, comprising a motor 20 arranged in the front inner cavity of a compressor shell 301 and a compressor body 30 arranged in the rear inner cavity of the compressor shell 301, a rotor 202 of the motor is connected with a compressor rotor 302, a compressor air inlet is arranged on the compressor shell 301 between the motor 20 and the compressor body 30, the compressor air inlet is connected with an inlet of a compression chamber 309 of the compressor through a compressor air inlet channel 305 arranged between the motor 20 and the compressor body 30, and a motor cooling structure is arranged on the compressor shell 301 and the motor 20 and cooperates with and communicates with the inlet of the compression chamber 309.

[0030] In the embodiment, the motor cooling structure comprises a motor cooling air inlet 204 arranged at the front end of the compressor shell 301, a motor cooling channel is arranged in the motor 20 and is connected with the compression chamber 309 of the compressor through a motor cooling working medium channel 208 arranged between the motor 20 and the compressor body 30.

[0031] The compressor inlet is the main inlet of the compressor, most of the refrigerant gas enters the compressor body 30 through the compressor inlet, and then is compressed by the compressor body 30 and discharged through the compressor exhaust outlet. Only a small part of the refrigerant gas enters the compressor through the motor cooling inlet 204, flows through the motor cooling channel, and then enters the compressor body 30, and is discharged after being compressed by the compressor body. The refrigerant gas entering the compressor through the motor cooling inlet 204 carries away a large amount of heat generated by the operation of the motor 20 when flowing through the motor cooling channel, ensuring stable operation of the motor.

[0032] In this embodiment, the motor cooling channel includes a motor rotor cooling channel 207 arranged on the rotor 202 of the motor in a circumferential direction, and a gap channel 206 is formed between the rotor 202 of the motor and the stator 201 of the motor. The stator cooling sleeve 205 is arranged outside the stator 201 of the motor in the compressor shell 301, and the stator cooling channel 211 is arranged on the stator cooling sleeve 205.

[0033] In this embodiment, the lower side (low position) of the compressor shell 301 between the motor 20 and the compressor body 30 is provided with a liquid collection recess 209, and the side wall of the liquid collection recess 209 is provided with a liquid discharge port 210 connected to the outside, which is used to discharge the collected condensed liquid and other substances. The height of the liquid discharge port 210 is higher than the bottom surface of the liquid collection recess 209, and when the liquid level reaches a certain height, the compressor is discharged through the liquid discharge port 210.

[0034] In this embodiment, the liquid collection recess 209 is arranged on the lower side of the motor cooling working medium channel 208; a cooling working medium inlet chamber 212 is formed between the motor cooling inlet 204 and the motor in the compressor shell 301, and the motor cooling inlet 204 is arranged on the upper part of the compressor shell. The front end of the compressor shell 301 is provided with an electrical box 203 for controlling the motor.

[0035] In this embodiment, the compressor shell 301 is located between the motor 20 and the compressor body 30, and the upper left and right sides are provided with compressor air inlets, respectively, the compressor left air inlet 303 and the compressor right air inlet 304, so as to realize that most of the refrigerant gas enters the compressor from the compressor left air inlet 303 and the compressor right air inlet 304. The compressor left air inlet 303 and the compressor right air inlet 304 are located on the left and right sides of the center of gravity of the compressor, which can effectively reduce the pipe weight of the external system and the shaking and vibration of the compressor caused by the fluid impact in the pipe. The screw compressor can be connected to the system through any compressor air inlet, and the pipe layout of the compressor system can be facilitated by switching the compressor air inlet. The screw compressor can also be connected to different systems through the two compressor air inlets at the same time, and the working state of the compressor air inlet can be switched by an external valve, so as to switch the working state of the screw compressor.

[0036] In this embodiment, the compressor shell 301 located between the motor 20 and the compressor body 30 is also provided with a compressor air inlet liquid outlet 310.

[0037] In this embodiment, the rear part of the compressor shell 301 and on both sides of the compression chamber 309 are provided with economizer air inlets, respectively, the left economizer air inlet 307 and the right economizer air inlet 308, and the refrigerant gas can also enter the compression chamber 309 directly from the 307 compressor left economizer inlet and the 308 compressor right economizer inlet, so as to improve the efficiency of the compressor. The lower side of the rear end of the compressor shell 301 is provided with an exhaust port 306, so as to output the compressed gas.

[0038] In this embodiment, the compression chamber is provided in the section of the compressor shell that cooperates with the screw part of the compressor rotor. The section of the compressor shell 301 between the motor 20 and the compressor body 30 is provided with a bearing seat structure 311 for supporting the shaft part of the compressor rotor 302, so as to provide support for the shaft part of the compressor rotor 302.

[0039] The flow path of the refrigerant: the refrigerant gas entering the compressor from the left compressor inlet 303 and the right compressor inlet 304, directly enters the compression chamber 309 through the compressor inlet passage 305 with a short flow path length and small flow resistance, thereby realizing small compressor suction resistance. The refrigerant gas entering the compressor from the motor cooling inlet 204 for cooling the motor 20, flows into the gap passage 206, the motor rotor cooling passage 207 and the stator cooling passage 211 respectively, and carries away the heat generated by the motor stator 201 and the rotor 202 of the motor during the flow through the motor 20, thereby maintaining the stable and efficient operation of the motor. The refrigerant gas flowing through the motor rotor gap passage 206, the motor rotor cooling passage 207 and the stator cooling passage 211 is collected in the cavity between the motor 20 and the compressor body 30, and then enters the compression chamber 309 through the motor cooling working medium passage 208. The refrigerant gas flowing into the compression chamber 309 is compressed by the rotating compressor rotor 302, and then discharged from the compressor through the discharge port 306. The refrigerant gas entering from the left economizer inlet 307 and the right economizer inlet 308 directly flows into the compression chamber 309. In addition, when the refrigerant gas flows in the semi-hermetic twin-screw compressor 10, it may become liquid due to condensation. To avoid the liquid refrigerant affecting the compression process after entering the compression chamber 309, a liquid collection recess 209 is arranged at a low position between the motor 20 and the compressor body 30, so that the liquid refrigerant is collected in the liquid collection recess 209 due to gravity, and when the liquid level reaches a certain height, it is discharged from the compressor through the liquid discharge port 210, thereby avoiding the accumulation of liquid substances in the compressor and affecting the normal use of the compressor.

[0040] A semi-hermetic twin-screw compressor system, comprising a semi-hermetic twin-screw compressor device, the left economizer inlet 307 and the right economizer inlet 308 are connected with an evaporator, the left compressor inlet 303 and the right compressor inlet 304 are connected with an economizer, the motor cooling inlet 204 is connected with a condenser outlet or a liquid reservoir outlet, the liquid discharge port 210 is connected with the compressor inlet liquid discharge port 310 through a liquid discharge branch path 501, a liquid pump 401 and a pump after liquid discharge branch path 502, the liquid discharge branch path 501 is provided with a liquid discharge path 505 and connected with a liquid discharge valve 402, the discharge port 306 is connected with the liquid pump 401 through a high-pressure gas path 503, and the high-pressure gas path 503 is provided with a discharge path 504 connected with a system oil separator.

[0041] The liquid pump 401 extracts the liquid in the liquid discharge port 210, and after the liquid pump 401 extracts the liquid, the liquid is collected in the compressor inlet liquid discharge port 310 through the pump post liquid discharge branch path 502. The liquid pump can be gas-powered or electric-powered. When the liquid pump 401 is gas-powered, the liquid pump 401 needs to be additionally connected to the compressor exhaust port 306 through the high-pressure gas path 503 to guide the high-pressure refrigerant gas into the liquid pump 401 as a power source. The liquid discharge valve 402 can be selected to discharge the liquid and other substances in the liquid collection recess 209 to other containers.

[0042] A semi-closed double screw compressor system includes a semi-closed double screw compressor device, a left economizer inlet 307 and a right economizer inlet 308 connected to an evaporator, a compressor left inlet 303 and a compressor right inlet 304 connected to an economizer, a motor cooling inlet 204 connected to a condenser outlet or a liquid accumulator outlet, the liquid discharge port 310 connected to a system oil separator through a liquid discharge branch path 501, a liquid pump 401, a pump post liquid discharge branch path 502, and an exhaust path 504, the exhaust port 306 connected to the exhaust path 504, and the liquid discharge branch path 501 provided with a liquid discharge path 505 and connected to a liquid discharge valve 402.

[0043] The liquid discharge port 210 is connected to the exhaust port 306 and is collected in the system oil separator together with the exhaust gas. The liquid pump 401 is provided at the outlet of the liquid discharge port 210 to pressurize the discharged liquid. The liquid discharge port 210 is connected to the liquid pump 401 through the liquid discharge branch path 501, and the pressurized discharged liquid is collected in the exhaust path 504 through the pump post liquid discharge branch path 502. In addition, the liquid discharge port 210 outlet is also connected to the liquid discharge valve 402 through the liquid discharge path 505, and the liquid discharge valve 402 can be selected to discharge the liquid and other substances in the liquid collection recess 209 to other containers.

[0044] The above only describes the preferred embodiments of the present application, and any changes and modifications made within the scope of the application should be included in the scope of the application.

Claims

1. A semi-hermetic double screw compressor device comprising a motor arranged in the inner cavity of the front part of the compressor housing and a compressor body arranged in the inner cavity of the rear part of the compressor housing, the rotor of the motor being connected to the rotor of the compressor, characterized in that, The compressor housing is provided with a compressor air inlet between the motor and the compressor body, the compressor air inlet is communicated with the compression chamber of the compressor through a compressor air passage arranged between the motor and the compressor body, and the compressor housing and the motor are provided with a motor cooling structure matched and communicated with the compression chamber.

2. A semi-hermetic twin screw compressor device according to claim 1, characterized in that, The motor cooling structure comprises a motor cooling air inlet arranged at the front end of the compressor housing, a motor cooling passage arranged in the motor, and a motor cooling working medium passage arranged between the motor and the compressor body and communicated with the compression chamber of the compressor.

3. A semi-hermetic twin screw compressor device according to claim 2, characterized in that, The motor cooling passage comprises a motor rotor cooling passage arranged on the rotor of the motor in a circumferential direction, and a gap passage formed between the rotor and the motor stator.

4. A semi-hermetic twin screw compressor device according to claim 2 or 3, characterized in that, A stator cooling sleeve is arranged outside the motor stator in the compressor housing, and the stator cooling sleeve is provided with a stator cooling passage.

5. A semi-hermetic twin screw compressor device according to claim 2 or 3, characterized in that, A cooling working medium inlet chamber is formed between the motor cooling air inlet and the motor in the compressor housing.

6. A semi-hermetic twin screw compressor device according to claim 1, characterized in that, A liquid collecting recess is arranged on the lower side of the compressor housing between the motor and the compressor body, and a liquid discharge port is arranged on the side wall of the liquid collecting recess.

7. A semi-hermetic twin screw compressor device according to claim 6, characterized in that, The compressor housing is provided with a compressor air inlet on the upper left and right sides between the motor and the compressor body, and the compressor housing is also provided with a compressor air inlet liquid discharge port between the motor and the compressor body, and the lower side of the rear end of the compressor housing is provided with an exhaust port.

8. A semi-hermetic twin screw compressor device according to claim 1, 2, 3 or 7, characterized in that, The rear part of the compressor housing is provided with an economizer air inlet communicated with the compression chamber on both sides.

9. A semi-hermetic twin screw compressor system comprising a semi-hermetic twin screw compressor device according to claim 7, characterized in that, The liquid discharge port is connected with the compressor air inlet liquid discharge port through a liquid discharge branch path, a liquid pump, and a pump post-liquid discharge branch path, the liquid discharge branch path is provided with a liquid external discharge path and connected with a liquid discharge valve, the exhaust port is connected with the liquid pump through a high-pressure gas path, and the high-pressure gas path is provided with an exhaust path connected with a system oil separator.

10. A semi-hermetic twin screw compressor system comprising a semi-hermetic twin screw compressor device according to claim 7, characterized in that, The liquid discharge port is connected with the system oil separator through a liquid discharge branch path, a liquid pump, a pump post-liquid discharge branch path, and an exhaust path, the exhaust port is connected with the exhaust path, and the liquid discharge branch path is provided with a liquid external discharge path and connected with a liquid discharge valve.

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