CN221347313U - Compressor diffuser, compressor and refrigeration equipment - Google Patents

Abstract

The utility model discloses a compressor diffuser, a compressor and refrigeration equipment, wherein an airflow channel which is communicated with a volute runner and the back side of an impeller is arranged on the diffuser, and the airflow channel provides high-speed airflow for the back side of the impeller so that the air pressure of the back side of the impeller is reduced. According to the utility model, the diffuser is provided with the airflow channel communicated with the volute flow channel and the back side of the impeller, so that the air pressure on the back side of the impeller is reduced, and the balance degree of the axial force of the air bearing is improved. The high-speed running characteristic of the gas suspension compressor with the small cooling capacity section is met, the problem that the axial bearing of the gas suspension compressor is easy to generate axial bearing collision and grinding failure is solved, so that the compressor has the advantage of high reliability when running at a high rotating speed, and meanwhile, the compressor can be integrated through Gu Gaodu due to the simple structure, and has obvious price advantage.

Description

Compressor diffuser, compressor and refrigeration equipment

Technical Field

The utility model relates to the technical field of compressors, in particular to a compressor diffuser, a compressor and refrigeration equipment.

Background

A centrifugal compressor is a device for compressing gas, which uses centrifugal force to feed the gas into a rotating centrifuge and increases the pressure of the gas during rotation. Compressors of this type are commonly used in air compression, refrigeration and air conditioning systems.

Centrifugal compressors are relatively high in rotational speed, and for this purpose, air bearings are usually used, which bear the load by using a gas film formed by gas and greatly reduce friction.

However, compared with an oil bearing, the air bearing has the problems of low bearing capacity, poor balance of the axial bearing and easy occurrence of collision and grinding failure of the axial bearing.

Disclosure of utility model

In order to solve the problem of axial force balance of an air bearing, the utility model provides a compressor diffuser, and the diffuser is provided with an airflow channel communicated with a volute runner and the back side of an impeller, so that the air pressure on the back side of the impeller is reduced, the balance degree of the axial force of the air bearing is improved, and further the compressor and refrigeration equipment utilizing the diffuser are provided.

According to the technical scheme, the compressor diffuser is designed, an air flow channel which is communicated with a volute runner and the back side of an impeller is arranged on the diffuser, and the air flow channel provides high-speed air flow for the back side of the impeller so that the air pressure of the back side of the impeller is reduced.

In certain embodiments, the outlet port of the airflow channel is directed radially outward of the impeller.

In certain embodiments, the outlet port of the airflow channel is oriented toward the impeller edge.

In certain embodiments, the inlet port of the airflow passage is located at an edge of the diffuser.

In certain embodiments, a plurality of the airflow channels are circumferentially and evenly distributed on the diffuser.

In certain embodiments, the number of gas flow channels is from 6 to 8.

In certain embodiments, the outlet port of the gas flow channel has a diameter of 1-4mm.

The compressor comprises the compressor diffuser.

In some embodiments, the compressor is a two-stage compressor, the impellers of different compression stages are connected to the same shaft, and the chambers of the diffusers of different compression stages are communicated.

In some embodiments, a through hole for communicating the cavity between the diffusers is arranged on the supporting seat for supporting the rotating shaft.

The refrigeration equipment is characterized by comprising the compressor and an evaporator, wherein cavities among diffusers of different compression stages are communicated with the evaporator.

Compared with the prior art, the utility model has the following beneficial effects:

according to the utility model, the diffuser is provided with the airflow channel communicated with the volute flow channel and the back side of the impeller, so that the air pressure on the back side of the impeller is reduced, and the balance degree of the axial force of the air bearing is improved. The high-speed running characteristic of the gas suspension compressor with the small cooling capacity section is met, the problem that the axial bearing of the gas suspension compressor is easy to generate axial bearing collision and grinding failure is solved, so that the compressor has the advantage of high reliability when running at a high rotating speed, and meanwhile, the compressor can be integrated through Gu Gaodu due to the simple structure, and has obvious price advantage.

Drawings

The present utility model will now be described in detail with reference to specific embodiments and drawings, which are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the utility model. The drawings illustrate generally, by way of example and not limitation, embodiments discussed herein. Wherein:

fig. 1 is a schematic view of a centrifugal compressor of the prior art.

Fig. 2 is an enlarged schematic view at a in fig. 1.

Fig. 3 is a schematic view of the centrifugal compressor of the present embodiment.

Fig. 4 is an enlarged schematic view at B in fig. 3.

Fig. 5 is an enlarged schematic view at C in fig. 3.

Fig. 6 is a schematic view of various axial forces experienced by the rotor.

Fig. 7 is an enlarged schematic view at D in fig. 6.

Fig. 8 is an enlarged schematic view at E in fig. 6.

Fig. 9 is a schematic view of the right diffuser also provided with an airflow passage.

In the figure, 1, a first cavity communication hole; 2. a second cavity communication hole; 3. a third cavity communication hole; 4. a return evaporator interface; 5. a return evaporator interface; 6. a left impeller; 7. a right impeller; 8. a left diffuser; 9. a left radial support; 10. a right diffuser; 11. a right radial support; 12. a left volute; 13. a right volute; 14. a left adjusting ring; 16. a motor stator; 15. a rotor; 17. an air flow channel; 171. an air outlet port; 172. an intake port.

Detailed Description

The following are specific examples of the present utility model and the technical solutions of the present utility model will be further described with reference to the accompanying drawings, but the present utility model is not limited to these examples, and the following embodiments do not limit the utility models according to the claims. Furthermore, all combinations of features described in the embodiments are not necessarily essential to the inventive solution.

The principles and structures of the present utility model are described in detail below with reference to the drawings and the examples.

Examples

A centrifugal compressor is a device for compressing gas, which uses centrifugal force to feed the gas into a rotating centrifuge and increases the pressure of the gas during rotation. Compressors of this type are commonly used in air compression, refrigeration and air conditioning systems.

As shown in fig. 1 and 2, the two-stage centrifugal compressor is a specially designed centrifugal compressor, and adopts the principle of two-stage compression. Unlike a conventional single-stage centrifugal compressor, a two-stage centrifugal compressor includes two centrifugal compression stages in its structure. This design allows the gas to undergo different pressure increases in two different stages of compression, ultimately reaching the desired high pressure state. The gas is first compressed to an intermediate pressure by a first centrifugal compression stage and then fed to a second compression stage for higher compression, eventually yielding the highest pressure required.

Dual stage centrifugal compressors are typically used in applications requiring very high pressure ratios or requiring more power. They play an important role in industrial air compression, refrigeration systems and air conditioning systems under specific requirements. This design may provide higher efficiency, reduced energy consumption, and in some cases, greater compression power.

Centrifugal compressors are relatively high in rotational speed, and for this purpose, air bearings are usually used, which bear the load by using a gas film formed by gas and greatly reduce friction.

The air bearing is loaded by utilizing an air film formed by gas, and friction is greatly reduced.

Compared with other types of bearings, the air bearing has the advantages of no oil, no pollution, small running resistance, simple structure, low mechanical loss and the like, overcomes the defects of many traditional liquid bearings, sliding bearings and rolling bearings, and is widely applied to high-speed rotating machinery and precision machining machinery and has wide market prospect.

The air bearing comprises a dynamic pressure bearing, a static pressure bearing, a dynamic-static pressure mixed bearing and the like,

The static pressure air bearing forms a static pressure air film through a restrictor by utilizing external high-pressure air, and dry friction phenomenon can not occur in the start-stop stage;

The dynamic pressure bearing brings gas between the bearing foil and the rotor 15 through the high-speed rotation of the rotor 15, and forms a high-pressure air film through air film extrusion, thereby playing a role in supporting the rotor 15, and the application range of the air bearing in the high-speed light-load field is extremely wide at present.

However, compared with an oil bearing, the air suspension bearing has the defect of low bearing capacity, so that the air suspension bearing is particularly important how to fully exert the characteristic of high rotation speed of the air suspension bearing aiming at the characteristic of the air suspension bearing, and how to accurately match the axial force of the compressor in the integrated air suspension centrifugal compressor is particularly important to avoid that the starting axial force exceeds the bearing capacity of the bearing.

In order to solve the problem of axial force balance of the air bearing, a compressor diffuser is provided, and through the arrangement of an air flow channel 17 communicated with a volute runner and the back side of an impeller on the diffuser, the air pressure of the back side of the impeller is reduced, so that the axial force balance degree of the air bearing is improved, and a compressor and refrigeration equipment using the diffuser are further provided.

Specifically, as shown in fig. 3, 4 and 5, a diffuser of a compressor for a refrigeration apparatus is illustrated as an example, the compressor is a two-stage compressor, impellers of different compression stages are connected at two ends of the same rotation shaft, that is, a left impeller 6 and a right impeller 7 are respectively connected at two ends of the rotation shaft of a motor rotor 15, and the motor rotor 15 is the rotor 15 of the compressor.

The impeller is a critical component in a centrifugal compressor for rotating and accelerating the rotation of a gas or fluid. In the first stage of a two-stage centrifugal compressor, gas or vapor enters the first impeller, which rotates to accelerate and push the gas outward, causing the gas to increase in kinetic energy and pressure. The second impeller is in the second stage of compression, re-accelerating and compressing the partially compressed gas, compressing the gas to a higher pressure level.

The aerodynamic force P1 of the wheel cover of the left impeller 6 and the aerodynamic force of the wheel back of the right impeller 7 borne by the compressor rotor 15 are directed to the right side of the compressor rotor 15; the aerodynamic force P6 of the cover of the right impeller 7, the aerodynamic force of the back of the left impeller 6 and the aerodynamic axial force of shoulders at two positions of the rotor 15 borne by the compressor rotor 15 are all directed to the left side of the compressor rotor 15.

It was found through experimental verification and theoretical analysis that the resultant force of the pneumatic axial force for a general centrifugal compressor is directed to the left side of the compressor in the figure (i.e., the first-stage compression side).

When the resultant force of the left pneumatic axial force is over-high compared with the resultant force of the right pneumatic axial force, the problem of abrasion of an air bearing of a compressor caused by the over-high resultant force of the pneumatic axial force is very easy to occur, and in the compressor, the proper amount of the resultant force of the left pneumatic axial force is very important when the resultant force of the left pneumatic axial force is from the back aerodynamic force of the left impeller 6 wheel, the aerodynamic force of the right impeller 7 wheel cover and the pneumatic axial force of two shoulders of the rotor 15 borne by the rotor 15 of the compressor.

For this purpose, the inventive design provides a nozzle structure on the left diffuser 8, by introducing air from the left volute 12 runner, high-speed air is introduced into the left diffuser 8 nozzle air introducing runner through the nozzle air introducing inlet, and then is obliquely directed to the back of the left impeller 6 through the nozzle outlet arranged on the left diffuser 8.

Specifically, an airflow channel 17 which is communicated with the volute runner and the back side of the impeller is arranged on the diffuser, and the airflow channel 17 provides high-speed airflow for the back side of the impeller so that the air pressure of the back side of the impeller is reduced. By introducing air from the flow passage of the left volute 12, high-speed gas is introduced into the airflow channel 17, and then is emitted to the back side of the impeller through the air outlet port 171 of the airflow channel 17 arranged on the left diffuser 8, and the high-speed gas is sprayed out through the nozzle formed by the air outlet port 171 to drive the gas in the back side cavity of the impeller to flow, so that the average pressure P2 in the back side cavity of the impeller is reduced, the balance degree of the axial force of the air bearing is improved, and a compressor and refrigeration equipment using the diffuser are further provided.

The diffuser is typically located between two stages of compression, between which the pressure and temperature of the gas is reduced. It allows the gas compressed in the first stage to be depressurized before entering the second stage, cooled and ready to enter the second stage compression stage, thereby improving overall efficiency.

The main task of the diffuser is to reduce the pressure of the gas coming out of the first stage of compression. This helps to ease the gas burden entering the second stage compression stage and provides more suitable conditions for the second stage compression.

Through the expansion process, the pressure of the gas is reduced, thereby causing a drop in temperature. Such cooling is highly beneficial to increase the efficiency of the overall compression system, as lower temperatures can reduce the heat loss of the gas during compression.

Diffusers are sometimes also used to prepare the gas for the second stage of compression. Reducing the pressure and temperature may allow the gas to more easily enter the second stage, reducing the burden on the second stage compressor components.

The scroll flow path in the centrifugal compressor refers to a passage structure inside the scroll for guiding gas or fluid from an inlet to an outlet. It plays a critical role in the operation of the compressor and helps direct gas or fluid into the impeller for compression.

The air outlet port 171 of the air flow channel 17 faces to the radial outer side of the impeller, so that the high-speed air flows out to drive the air in the cavity on the back side of the impeller to flow out quickly, and the high-pressure air outside tissues enters.

The outlet port 171 of the air flow channel 17 is directed towards the impeller edge to facilitate rapid discharge out of the gap between the impeller edge and the diffuser.

The inlet port 172 of the air flow channel 17 is located at the edge of the diffuser, and a high-speed air flow is generated at the outlet port 171 of the air flow channel 17 due to the large pressure difference between the edge of the diffuser and the back of the air flow.

The plurality of air flow channels 17 are circumferentially distributed on the diffuser so as to enable the air flow to generate a force as uniform as possible on the circumferential direction of the back side of the impeller.

In general, the number of the air flow passages is preferably 6-8, and the compressor efficiency may be affected by too much air flow passages, and the pressure P2 may not be reduced by too little air flow passages.

The diameter of the air outlet port of the air flow channel is preferably 1-4mm, otherwise, the too large and too small diameter and the too large and too small number can have reverse influence on energy efficiency and pressure reduction.

Meanwhile, the cavity pressure P3 between the left diffuser 8 and the left radial support 9 and the cavity pressure P4 between the right diffuser 10 and the right radial support 11 are also important to the left pneumatic axial force, and before no communication hole is arranged in the cavity, the pressure value of P3 is mainly influenced by the leakage of the gas flowing into the left volute 12 after the compression of the left impeller to the left impeller back pressure value P2; the pressure value of P4 is mainly influenced by the fact that the gas flowing into the right volute 13 after being compressed by the right impeller leaks to the back pressure value P5 of the right impeller, the gas pressure value of the compressor is larger in general, and the pressure of the evaporator of the unit is more than P4> P3>, so that the value of P3 and P4 is also important to be reduced to the greatest extent;

as shown in fig. 6, 7 and 8, in the compressor structure of the present embodiment, the first cavity communication hole 1 is disposed on the left radial support and the left and right thrust bearings, the second cavity communication hole 2 is disposed on the motor stator 16, and the third cavity communication hole 3 is disposed on the right radial support, so that all small cavities inside the compressor are completely connected in series, and meanwhile, the left and right compressor motor cavities are provided with the back evaporator interface 4 and the back evaporator interface 5, so that the compressor cavities and evaporators with lower pressure of the chiller are connected, thereby maximally reducing the effective values of P3 and P4, reducing the left pneumatic axial force, comprehensively enabling the total pneumatic axial force value to tend to 0, and effectively adjusting the value and direction of the total axial force by controlling the diameter of the left adjusting ring 14 according to the adjusting effect.

Of course, as shown in fig. 9, the nozzle installation position may be adjusted according to the actual direction of the axial force, and if the integrated axial force is directed to the right, the nozzle may be installed in the right diffuser.

The compressor of this embodiment can compromise the problem of solving the easy emergence axial bearing of gas suspension compressor axial bearing and bump the mill failure when satisfying the high rotational speed operational characteristic of little cold volume section gas suspension compressor to make the compressor have the advantage that the reliability is high concurrently when satisfying high rotational speed operation, this compressor simultaneously owing to simple structure, can Gu Gaodu integration during the period, the compressor has obvious price advantage concurrently.

Air bearing designs are commonly used in centrifugal compressors to reduce axial forces and axial vibrations, but axial force imbalance may sometimes occur.

If the gas supply is uneven, imbalance in the gas pressure in the air bearing may result, thereby making the offset of the axial force by the air bearing uneven.

If the gas is not sealed well or leaks, the gas pressure in the air bearing may change, resulting in imbalance in axial force.

Air bearing assemblies such as bearing surfaces or seal rings may degrade in performance due to excessive use time or damage, thereby causing an imbalance in axial forces.

If the flow of gas inside the bearing is impeded, uneven gas pressure may be generated by the air bearing, thereby affecting the balance of the axial forces.

Controlling the balance of axial forces of a centrifugal compressor air bearing typically requires taking some measure to ensure equalization of gas pressure and stable operation inside the air bearing.

The air supply to the inside of the air bearing is ensured to be uniform, and the overlarge pressure difference of different parts is avoided. This can be achieved by balancing the gas supply system and the gas channels, ensuring a uniform distribution of the pressure and flow of the gas into the bearing.

And (3) regularly maintaining the air bearing, including cleaning the air bearing and the corresponding gas channel, and checking whether the sealing element is intact.

Regular maintenance can ensure smooth flow of gas in the air bearing and reduce axial force problem caused by uneven pressure. Some high-end centrifugal compressors may be equipped with a specialized axial force compensation system. The system can automatically adjust the gas flow and the pressure according to the pressure change condition in the air bearing so as to maintain the balance of axial force. During the design phase of the centrifugal compressor, improvements may be considered, such as adding gas flow channels, designing a more efficient axial force balancing system, or improving the gas supply system to ensure a more uniform gas pressure and flow inside the air bearing. The comprehensive application of the methods can effectively control and maintain the balance of axial force of the air bearing of the centrifugal compressor, and improve the stability and performance of equipment.

Centrifugal compressors play an important role in the refrigeration field. They are commonly used in refrigeration systems to compress a low pressure, low temperature refrigerant gas into a high pressure, high temperature gas, and then to effect a refrigeration cycle through condensation and expansion processes.

At the start of the refrigeration cycle, the compressor sucks and compresses the refrigerant gas, and raises the pressure to a high-pressure and high-temperature state. In this process, both the temperature and pressure of the gas are significantly increased.

The compressed high-temperature high-pressure gas passes through a condenser, and the refrigerant gas emits heat and is condensed into liquid state. This allows the heat released by the gas to be transferred to the surrounding environment, thereby cooling the refrigerant.

The condensed liquid refrigerant is passed through an expansion valve or throttling device, reduced in pressure and evaporated to a gaseous state. During this process, the refrigerant evaporates from high to low pressure, absorbing external heat to maintain equilibrium, causing the attached near-ambient temperature to drop. After evaporation, the gas is again sucked into the centrifugal compressor and the cycle is repeated.

The high efficiency of centrifugal compressors and the ability to handle large volumes of gas flows make them very popular in the commercial and industrial refrigeration fields. They are commonly used in large refrigeration systems, such as central air conditioning systems, refrigerators and industrial refrigeration equipment.

The communication of the motor cavity of the centrifugal compressor with the evaporator is typically done to achieve specific system design or operational requirements. This design may be used in some particular types of compressor systems, but not all centrifugal compressors may employ this configuration.

Connecting the motor cavity to the evaporator may cool the motor with a refrigerant in the evaporator. This design can help reduce the operating temperature of the motor, helping to improve the efficiency and life of the motor. By using the low temperature refrigerant in the evaporator to cool the motor, the whole system can keep a lower temperature during operation, thereby reducing heat loss and improving energy efficiency.

In some systems, connecting the motor cavity to the evaporator may simplify the design of the piping and cooling system, reduce the number of components, and reduce the complexity of the system.

Particularly, when the motor is operated in a high-temperature environment or needs long-time high-load operation, the motor cavity and the evaporator are connected, so that the motor can be effectively prevented from overheating, and the reliability of equipment is improved.

The specific embodiments described herein are offered by way of example only to illustrate the spirit of the utility model. Those skilled in the art may make various modifications or additions to the described embodiments or substitutions thereof without departing from the spirit of the utility model or exceeding the scope of the utility model as defined in the accompanying claims.

Although some terms are used more herein, the possibility of using other terms is not excluded. These terms are used merely for convenience in describing and explaining the nature of the utility model; they are to be interpreted as any additional limitation that is not inconsistent with the spirit of the present utility model. The order of execution of the operations, steps, and the like in the apparatuses and methods shown in the specification and the drawings may be any order as long as the order is not particularly limited, and the output of the preceding process is not used in the following process. The use of similar ordinal terms (e.g., "first," "then," "second," "again," "then," etc.) for convenience of description does not necessarily imply that they are necessarily performed in such order.

It will be appreciated by those of ordinary skill in the art that all directional references (e.g., above, below, upward, downward, top, bottom, left, right, vertical, horizontal, etc.) are descriptive of the drawings to aid the reader in understanding, and do not denote (e.g., position, orientation, use, etc.) limitation of the scope of the utility model defined by the appended claims, but rather are intended to facilitate describing the utility model and simplifying the description, the orientation words do not indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, the orientation words "inside and outside" referring to the inside and outside of the profile of the components themselves, unless otherwise indicated.

Spatially relative terms, such as "above … …," "above … …," "upper surface on … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Additionally, some ambiguous terms (e.g., substantially, certain, generally, etc.) may refer to slight imprecision or slight deviation of conditions, amounts, values, or dimensions, etc., some of which are within manufacturing tolerances or tolerances. It should be noted that, the terms "first," "second," and the like are used for defining the components, and are merely for convenience in distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, so they should not be construed as limiting the scope of the present application.

Claims (11)

1. The compressor diffuser is characterized in that an airflow channel which is communicated with a volute runner and the back side of the impeller is arranged on the diffuser, and the airflow channel provides high-speed airflow for the back side of the impeller so that the air pressure of the back side of the impeller is reduced.

2. The compressor diffuser of claim 1, wherein the outlet port of the gas flow passage is directed radially outward of the impeller.

3. The compressor diffuser of claim 2, wherein the outlet port of the airflow passage is oriented toward the impeller edge.

4. The compressor diffuser of claim 1, wherein the inlet port of the airflow passage is located at an edge of the diffuser.

5. The compressor diffuser of claim 1, wherein a plurality of said gas flow passages are circumferentially and uniformly distributed on said diffuser.

6. The compressor diffuser of claim 1, wherein the number of gas flow passages is 6-8.

7. The compressor diffuser of claim 1, wherein the outlet port of the gas flow passage has a diameter of 1-4mm.

8. A compressor comprising a compressor diffuser according to any one of claims 1 to 7.

9. The compressor of claim 8, wherein the compressor is a two-stage compressor, the impellers of different compression stages are connected to the same shaft, and the chambers of the diffusers of different compression stages are communicated.

10. The compressor of claim 9, wherein a support seat supporting the rotation shaft is provided with a through hole communicating with a cavity between the diffusers.

11. Refrigeration device comprising a compressor according to any one of claims 9 or 10, further comprising an evaporator, with which the cavities between the diffusers of the different compression stages are in communication.