阅读说明：本技术 冷水机组 (Water chilling unit ) 是由 李思茹 刘增岳 朱万朋 韩聪 殷纪强 俞国新 刘洋 于 2020-05-15 设计创作，主要内容包括：本申请涉及制冷设备技术领域,公开一种冷水机组,包括：离心压缩机,包括冷媒压缩腔和气浮轴承；过热装置,进口端通过第一单向阀与所述冷媒压缩腔的排气口连接,出口端与所述气浮轴承的供气口连接,被配置为所述气浮轴承提供饱和气体或者过热气体。本公开实施例提供的冷水机组,在离心压缩机的气浮轴承的供气口设置了过热装置,通过过热装置对气浮轴承的供气进行加热操作,能够保证进入气浮轴承的气体为饱和气体或者过热气体,防止气浮轴承的供给气体中含有液体,影响离心压缩机的正常运行。(The application relates to the technical field of refrigeration equipment, and discloses a water chilling unit, includes: the centrifugal compressor comprises a refrigerant compression cavity and an air bearing; and the inlet end of the overheating device is connected with the exhaust port of the refrigerant compression cavity through a first one-way valve, the outlet end of the overheating device is connected with the gas supply port of the air bearing, and the overheating device is configured to provide saturated gas or overheated gas for the air bearing. The water chilling unit provided by the embodiment of the disclosure is characterized in that the overheating device is arranged at the air supply port of the air bearing of the centrifugal compressor, the overheating device is used for heating the air supply of the air bearing, the air entering the air bearing can be ensured to be saturated gas or overheated gas, and the phenomenon that the normal operation of the centrifugal compressor is influenced due to the fact that liquid is contained in the supplied gas of the air bearing is prevented.)

1. A chiller, comprising:

the centrifugal compressor comprises a refrigerant compression cavity and an air bearing;

and the inlet end of the overheating device is connected with the exhaust port of the refrigerant compression cavity through a first one-way valve, the outlet end of the overheating device is connected with the gas supply port of the air bearing, and the overheating device is configured to provide saturated gas or overheated gas for the air bearing.

2. The chiller according to claim 1, wherein said superheating means comprises:

a housing;

a heating module disposed inside or on a side wall of the housing and configured to heat gas within the superheating device.

3. The water chilling unit of claim 2, further comprising:

and the first electromagnetic valve is connected with the heating module and the first one-way valve and is configured to be controlled to conduct the refrigerant compression cavity and the overheating device.

4. The water chilling unit of claim 3, further comprising:

the first heat exchanger is connected with an air outlet of the refrigerant compression cavity through a first one-way valve;

a gas compression device having a gas inlet connected to the gas outlet end of the first heat exchanger and a gas outlet connected to the inlet end of the superheating device, configured to compress the gas exiting the first heat exchanger to provide gas to the superheating device.

5. The water chilling unit according to claim 4, further comprising:

a second solenoid valve connecting an inlet of the gas compression device and a gas outlet of the first heat exchanger, configured to controllably communicate the first heat exchanger and the superheating device.

6. The water chilling unit according to claim 5, further comprising:

and the control device is connected with the first electromagnetic valve and/or the second electromagnetic valve and is configured to control the opening degree of the first electromagnetic valve and/or the second electromagnetic valve.

7. The water chilling unit according to claim 6, further comprising:

a first sensor, arranged at the inlet end of the superheating device and connected with the control device, and configured to detect the pressure and/or temperature of the gas entering the superheating device; and/or the presence of a gas in the gas,

and the first flow meter is arranged at the inlet end of the overheating device, is connected with the control device and is configured to detect the flow of the gas entering the overheating device.

8. The water chilling unit according to claim 7, further comprising:

a second sensor, arranged at the outlet end of the superheating device and connected with the control device, and configured to detect the pressure and/or temperature of the gas flowing out of the superheating device; and/or the presence of a gas in the gas,

and the second flow meter is arranged at the outlet end of the overheating device, is connected with the control device and is configured to detect the flow of the gas flowing out of the overheating device.

9. The water chilling unit of claim 8, further comprising:

and the third electromagnetic valve is connected with the outlet end of the overheating device and the air supply port of the air bearing, is connected with the control device, and is configured to be controlled to conduct the overheating device and the air bearing.

10. The water chilling unit of claim 9, further comprising:

and the second one-way valve is arranged at the inlet end of the overheating device.

Technical Field

The application relates to the technical field of refrigeration equipment, for example to a water chilling unit.

Background

At present, the gas lubrication technology is a high and new technology which is rapidly developed in the middle of the 20 th century. Its emergence has made lubrication technology a qualitative leap. Gas bearings are the core item developed from this technology, which is a mechanical component that uses a gas film to support a load or reduce friction. Compared with a rolling bearing and an oil sliding bearing, the gas bearing has four advantages of high speed, high precision, low power consumption and long service life. The bearing speed is improved by 5-10 times, the supporting precision is improved by 2 orders of magnitude, the power consumption is reduced by 3 orders of magnitude, and the service life of the bearing is prolonged by tens of times. The gas lubrication technology comprises dynamic pressure lubrication, static pressure lubrication and dynamic and static pressure lubrication, wherein the dynamic pressure lubrication is self-acting lubrication, the static pressure lubrication is lubrication which provides gas pressure from the outside, and the dynamic and static pressure lubrication has the characteristics of both the dynamic and static pressure lubrication. The type of lubrication may be selected as appropriate according to specific engineering requirements during design.

The static pressure lubricating gas bearing used in centrifugal compressor needs external pressure device to raise the pressure of refrigerant and continuously supply high pressure gaseous refrigerant to bearing, the existing pressure supply device is generally gas supply tank, i.e. electric energy is used to heat electric heating tube in gas supply tank to make liquid refrigerant be heated and evaporated into gas. However, since the gaseous refrigerant is evaporated and then rises to be discharged from the top of the gas holder, the gaseous refrigerant encounters the liquid refrigerant that has just flowed into the gas holder during the rising process, and droplets are easily entrained. When the bearing supplies gas and is internally doped with liquid drops, the normal operation of a bearing gas film is disturbed, the operation of a rotor and the bearing is influenced, the bearing is damaged, and even a shaft seizing accident is caused if the bearing is serious.

In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art:

when the air bearing is supplied with air, a refrigerant at the outlet of the compressor cannot be ensured to be in a saturated gas state, so that the gas supplied to the air bearing cannot be ensured to be in a saturated gas state, liquid possibly exists, condensation phenomenon may occur in the operation process to cause gas liquefaction, and the normal operation of the bearing can be influenced after the liquid enters the bearing gap.

Disclosure of Invention

The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview nor is intended to identify key/critical elements or to delineate the scope of such embodiments but rather as a prelude to the more detailed description that is presented later.

The embodiment of the disclosure provides a water chiller, which can prevent liquid from being entrained in air supply of an air bearing, so that the air supply of the air bearing is saturated gas or superheated gas.

In some embodiments, a chiller includes: the centrifugal compressor comprises a refrigerant compression cavity and an air bearing; and the inlet end of the overheating device is connected with the exhaust port of the refrigerant compression cavity through a first one-way valve, the outlet end of the overheating device is connected with the gas supply port of the air bearing, and the overheating device is configured to provide saturated gas or overheated gas for the air bearing.

The water chilling unit provided by the embodiment of the disclosure can realize the following technical effects:

the gas supply port of the air bearing of the centrifugal compressor is provided with the overheating device, the overheating device is used for heating the gas supply of the air bearing, the gas entering the air bearing can be saturated gas or overheated gas, and the phenomenon that the normal operation of the centrifugal compressor is influenced due to the fact that liquid is contained in the supplied gas of the air bearing is prevented.

The foregoing general description and the following description are exemplary and explanatory only and are not restrictive of the application.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the accompanying drawings and not in limitation thereof, in which elements having the same reference numeral designations are shown as like elements and not in limitation thereof, and wherein:

fig. 1 is a schematic structural diagram of a water chiller according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of another water chilling unit provided in the embodiment of the present disclosure.

Reference numerals:

1. a centrifugal compressor; 11. a refrigerant compression chamber; 12. an air bearing; 2. an overheating device; 21. a housing; 22. a heating module; 31. a first check valve; 32. a second one-way valve; 41. a first solenoid valve; 42. a second solenoid valve; 43. a third electromagnetic valve; 5. a first heat exchanger; 6. a gas compression device; 71. a first sensor; 72. a first flow meter; 73. a second sensor; 74. a second flow meter.

Detailed Description

So that the manner in which the features and elements of the disclosed embodiments can be understood in detail, a more particular description of the disclosed embodiments, briefly summarized above, may be had by reference to the embodiments, some of which are illustrated in the appended drawings. In the following description of the technology, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, one or more embodiments may be practiced without these details. In other instances, well-known structures and devices may be shown in simplified form in order to simplify the drawing.

The terms "first," "second," and the like in the description and in the claims, and the above-described drawings of embodiments of the present disclosure, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the present disclosure described herein may be made. Furthermore, the terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions.

In the embodiments of the present disclosure, the terms "upper", "lower", "inner", "middle", "outer", "front", "rear", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings. These terms are used primarily to better describe the disclosed embodiments and their examples and are not intended to limit the indicated devices, elements or components to a particular orientation or to be constructed and operated in a particular orientation. Moreover, some of the above terms may be used to indicate other meanings besides the orientation or positional relationship, for example, the term "on" may also be used to indicate some kind of attachment or connection relationship in some cases. The specific meanings of these terms in the embodiments of the present disclosure can be understood by those of ordinary skill in the art as appropriate.

In addition, the terms "disposed," "connected," and "secured" are to be construed broadly. For example, "connected" may be a fixed connection, a detachable connection, or a unitary construction; can be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements or components. Specific meanings of the above terms in the embodiments of the present disclosure can be understood by those of ordinary skill in the art according to specific situations.

In the embodiment of the present disclosure, the character "/" indicates that the preceding and following objects are in an or relationship. For example, A/B represents: a or B.

The term "and/or" is an associative relationship that describes objects, meaning that three relationships may exist. For example, a and/or B, represents: a or B, or A and B.

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

Fig. 1 is a schematic structural diagram of a water chilling unit according to an embodiment of the present disclosure. Referring to fig. 1, an embodiment of the present disclosure provides a water chiller including a centrifugal compressor 1 and a superheating device 2. The centrifugal compressor 1 comprises a refrigerant compression cavity 11 and an air bearing 12; the inlet end of the superheating device 2 is connected to the exhaust port of the refrigerant compression chamber 11 through the first check valve 31, and the outlet end thereof is connected to the air supply port of the gas bearing 12, and the superheating device 2 is configured to supply saturated gas or superheated gas to the gas bearing 12.

The centrifugal compressor 1 comprises a refrigerant compression cavity 11, and the refrigerant enters the refrigerant compression cavity 11 and is compressed into high-temperature and high-pressure gas and then discharged out of the centrifugal compressor, so that a circulating refrigerant is provided for the water chilling unit.

The centrifugal compressor 1 further includes an air bearing 12 for providing power for the refrigerant compression cavity 11 to compress the refrigerant. The air bearing 12 is a sliding bearing using gas as a lubricant, and the support member has no solid contact when starting or stopping, so that no solid abrasion occurs. Alternatively, the air bearing 12 is a static pressure air bearing. The air bearing 12 has a simple working principle, has large bearing capacity and rigidity, can normally work at high speed, low speed and even zero speed, and has the advantages of high speed, high precision, low power consumption, long service life and the like, so the air bearing has strong adaptability and wide application.

The superheating device 2 is disposed in front of the air supply port of the air bearing 12, and has an inlet end connected to the air discharge port of the refrigerant compression chamber 11 via a first check valve 31 and an outlet end connected to the air supply port of the air bearing 12. Thus, after the gas provided by the refrigerant compression cavity 11 for the gas bearing 12 is heated and stabilized by the superheating device 2, the gas can be prevented from containing liquid, the superheated gas or saturated gas can be provided for the gas bearing 12, the pressure of the supplied gas can be ensured to be stable, and the stable operation of the centrifugal compressor 1 can be realized.

A first check valve 31 is provided at an outlet of the refrigerant compression chamber 11. Therefore, the condition of backflow of gas discharged by the centrifugal compressor 1 can be prevented, and the safe operation of the centrifugal compressor 1 is ensured.

Optionally, the chiller further comprises a second heat exchanger to which the exhaust gas of the air bearing 12 is connected. Thus, the working gas in the air bearing 12 returns to the compression cavity of the centrifugal compressor 1 through the second heat exchanger, and continues to provide the circulating refrigerant for the chiller and the gas for the air bearing 12.

By adopting the water chilling unit provided by the embodiment of the disclosure, the overheating device is arranged at the air supply port of the air bearing of the centrifugal compressor, the air supply of the air bearing is heated by the overheating device, the air entering the air bearing can be saturated gas or overheated gas, and the influence on the normal operation of the centrifugal compressor due to the liquid contained in the supplied gas of the air bearing is prevented.

In some embodiments, the superheating device 2 comprises a housing 21 and a heating module 22. The heating module 22 is provided inside or on a side wall of the housing 21 and configured to heat the gas inside the superheating device 2.

Alternatively, the heating module 22 is heated by means of an electric heating tube, which may be disposed inside the housing 21. The electric heating tube has the advantages of high heating speed, high efficiency and compact structure. In this way, the heating module 22 can rapidly bring the gas supplied to the air bearing 12 to a preset temperature or a required temperature, and the cost of the overheating device can be reduced because the price of the electric heating pipe is low.

Alternatively, the heating module 22 is heated by means of a semiconductor heating sheet, which may be disposed on a side wall of the housing 21. The semiconductor is fast to heat and high in precision. In this way, the semiconductor heating fins heat the side wall of the housing 21, so that the gas in the superheating device 2 can be heated in a short time, the temperature in the superheating device 2 can be accurately controlled, and the semiconductor heating fins have no moving parts, so that the reliability is high.

Alternatively, the heating module 22 is heated by electromagnetic heating, and the electromagnetic coil may be wound around the side wall of the housing 21. The gas in the overheating device 2 is heated in an electromagnetic heating mode, so that the temperature control is accurate, the safety and the reliability are realized, the heating speed is high, and the efficiency and the energy conservation are realized.

In some embodiments, the chiller further comprises a first solenoid valve 41. The first solenoid valve 41 is connected to the heater module 22 and the first check valve 31, and is configured to controllably communicate the refrigerant compression chamber 11 and the superheating device 2.

One end of the first solenoid valve 41 is connected to the first check valve 31, and the other end of the first solenoid valve 41 is connected to the heating module 22. Thus, the first solenoid valve 41 can be controlled to conduct the passage between the refrigerant compression cavity 11 and the superheating device 2, so that a part of the gas discharged from the refrigerant compression cavity 11 enters the air bearing 12 through the superheating device 2 to supply gas to the air bearing 12; alternatively, the first solenoid valve 41 may be controlled to close the passage between the refrigerant compression chamber 11 and the superheating device 2.

Optionally, a first filter is further disposed between the first electromagnetic valve 41 and the first check valve 31. In this way, it is possible to prevent the gas entering the air bearing 12 through the superheating device 2 from containing impurities, and to ensure the normal operation of the air bearing 12. Optionally, a third one-way valve is arranged in front of the first filter. In this way, the reverse flow of the gas passing through the first solenoid valve 41 can be prevented.

The path through which the high-temperature and high-pressure gas discharged from the centrifugal compressor 1 passes through the first check valve 31 and the first solenoid valve 41 to supply gas to the air bearing 12 is referred to as a first gas supply line.

In some embodiments, the chiller further comprises a first heat exchanger 5 and a gas compression device 6. The first heat exchanger 5 is connected with the air outlet of the refrigerant compression cavity 11 through a first check valve 31; and a gas compression device 6, wherein a gas inlet is connected with the gas outlet end of the first heat exchanger 5, a gas outlet is connected with the inlet end of the overheating device 2, and the gas compression device is configured to compress the gas discharged from the first heat exchanger 5 and provide the gas for the overheating device 2.

The first heat exchanger 5 is connected to an exhaust port of the refrigerant compression chamber 11 through a first check valve 31. Thus, a part of the gas discharged from the refrigerant compression chamber 11 flows into the superheating device through the first solenoid valve 41, and the other part of the gas flows into the first heat exchanger.

The gas inlet of the gas compression device 6 is connected to the gas outlet of the first heat exchanger 5, so that part of the refrigerant in the gaseous state entering the first heat exchanger 5 can be led out to the gas compression device 6; the gas outlet of the gas compression device 6 is connected with the inlet end of the overheating device 2, so that the gaseous refrigerant discharged from the first heat exchanger 5 can be compressed and discharged to the overheating device 2, and the superheated gas or the saturated gas can be provided for the air bearing 12 through the heating or pressure stabilizing effect of the overheating device 2.

The path through which the high-temperature and high-pressure gas discharged from the centrifugal compressor 1 passes through the first heat exchanger 5 and the gas compression device 6 to supply gas to the gas bearings 12 is referred to as a second gas supply line.

In some embodiments, the chiller further includes a second solenoid valve 42. A second solenoid valve 42, connecting the gas inlet of the gas compression device and the gas outlet of the first heat exchanger, is configured to controllably communicate the first heat exchanger 5 with the superheating device 2.

One end of the second electromagnetic valve 42 is connected to the gas inlet of the gas compression device 6, and the other end of the second electromagnetic valve 42 is connected to the gas outlet of the first heat exchanger 5. Thus, the second solenoid valve 42 can be controlled to conduct the passage between the first heat exchanger 5 and the superheating device 2, so that part of the gaseous refrigerant in the first heat exchanger 5 is led out to the gas compression device 6 to be compressed and then enters the superheating device 2 to supply gas for the gas bearing 12; alternatively, the second solenoid valve 42 may be controlled to close the passage between the first heat exchanger 5 and the superheating device 2.

Optionally, a second filter is further disposed between the second electromagnetic valve 42 and the gas compression device 6. Thus, impurities contained in the gas can be prevented, and the normal operation of the air bearing 12 can be ensured. Optionally, a fourth one-way valve is arranged in front of the second filter. Thus, the gas passing through the second solenoid valve 42 can be prevented from flowing backward, which causes a unit failure.

In some embodiments, the chiller further comprises a control device. The control device is connected to the first solenoid valve 41 and/or the second solenoid valve 42, and is configured to control the opening degree of the first solenoid valve 41 and/or the second solenoid valve 42.

The control device is connected to the first solenoid valve 41 and/or the second solenoid valve 42, and is capable of controlling the opening degree of the first solenoid valve 41 and/or the second solenoid valve 42, so as to control the flow rate of the gas passing through the first solenoid valve 41 and/or the second solenoid valve 42, that is, the flow rate of the first gas supply line and/or the second gas supply line of the air bearing 12. Alternatively, the opening or closing of the first solenoid valve 41 and/or the second solenoid valve 42 can be controlled, thereby controlling the opening or closing of the first air supply line and/or the second air supply line of the air bearing 12.

In some embodiments, the chiller further comprises a first sensor 71 and a first flow meter 72. The first sensor 71 is arranged at the inlet end of the superheating device 2 and connected to the control device, and is configured to detect the pressure and/or temperature of the gas entering the superheating device 2; and/or a first flow meter 72, disposed at an inlet end of the superheating device 2 and connected to the control device, configured to detect the flow rate of the gas entering the superheating device 2.

At the inlet end of the superheating means 2, there are provided a first sensor 71 and a first flow meter 72 connected to the control means. The first sensor 71 detects the pressure and/or temperature of the gas entering the superheating device 2. When the pressure detected by the first sensor 71 is lower than the preset air supply pressure of the air bearing 12 and/or when the temperature detected by the first sensor 71 is lower than the preset air supply temperature of the air bearing 12, the control device controls the heating module 22 to start heating, so that the gas entering the overheating device 2 reaches a saturated gas state or an overheated gas state. When the pressure detected by the first sensor 71 is greater than or equal to the preset air supply pressure of the air bearing 12, and/or when the temperature detected by the first sensor 71 is greater than or equal to the preset air supply temperature of the air bearing 12, the heating module is not turned on.

The first flow meter 72 detects the flow rate of the gas entering the superheating device 2. When a large fluctuation occurs in the flow rate signal detected by the first flow meter 72, the control device controls the opening degree of the first solenoid valve 41 and/or the second solenoid valve 42, thereby adjusting the flow rate of the first air supply line and/or the second air supply line of the air bearing 12.

In some embodiments, the chiller further includes a second sensor 73 and a second flow meter 74. A second sensor 73 is arranged at the outlet end of the superheating device 2 and connected to the control device, configured to detect the pressure and/or temperature of the gas flowing out of the superheating device 2; and/or a second flow meter 74, disposed at an outlet end of the superheating device 2 and connected to the control device, configured to detect the flow rate of the gas flowing out of the superheating device 2.

At the outlet end of the superheating means 2, a second sensor 73 and a second flow meter 74 are provided, which are connected to the control means. The second sensor 73 detects the pressure and/or temperature of the gas flowing out of the superheating device 2. When the pressure detected by the second sensor 73 is lower than the preset air supply pressure of the air bearing 12 and/or when the temperature detected by the second sensor 73 is lower than the preset air supply temperature of the air bearing 12, the control device controls the heating module 22 to start heating, so that the gas entering the overheating device 2 reaches a saturated gas state or an overheated gas state. When the pressure detected by the second sensor 73 is greater than or equal to the preset air supply pressure of the air bearing 12, and/or when the temperature detected by the second sensor 73 is greater than or equal to the preset air supply temperature of the air bearing 12, the heating module is not turned on.

The second flow meter 74 detects the flow rate of the gas entering the superheating device 2. When a large fluctuation occurs in the flow rate signal detected by the second flow meter 74, or when the flow rate signal detected by the second flow meter 74 is smaller than the preset air supply flow rate of the air bearing 12, the control device controls the opening degree of the first solenoid valve 41 and/or the second solenoid valve 42, thereby adjusting the flow rate of the first air supply line and/or the second air supply line of the air bearing 12.

In some embodiments, the chiller further includes a third solenoid valve 43. The third solenoid valve 43 is connected to the outlet end of the superheating device 2 and the air supply port of the air bearing 12, is connected to the control device, and is configured to controllably conduct the superheating device 2 and the air bearing 12.

One end of the third electromagnetic valve 43 is connected to the outlet end of the overheating device 2, the other end is connected to the air supply port of the air bearing 12, and the third electromagnetic valve 43 is connected to the control device, and the third electromagnetic valve 43 can be controlled by the control device to conduct the passage of the overheating device 2 and the air bearing 12. Alternatively, the control means controls the opening degree of the third electromagnetic valve 43 when the flow rate detected by the second flow meter 74 is larger than a preset air supply flow rate of the air bearing 12. In this way, the flow rate of the supply air to the air bearing 12 can be adjusted.

In some embodiments, the chiller further includes a second one-way valve 32. A second one-way valve 32 is provided at the inlet end of the superheating device 2.

A second one-way valve 32 is provided at the inlet end of the superheating device 2. This prevents backflow of gas into the superheating device 2, which could cause unit failure.

Optionally, the water chilling unit further includes a throttling device disposed between the first heat exchanger 5 and the second heat exchanger to ensure the circulation of the refrigerant in the refrigeration system.

Optionally, a second filter is arranged before the throttling device.

Optionally, the second heat exchanger is connected to the centrifugal compressor 1 through a fourth solenoid valve, and the fourth solenoid valve is connected to the control device. In this way, the fourth solenoid valve can be controlled to open the passage between the second heat exchanger and the centrifugal compressor 1; or the opening of the fourth electromagnetic valve is controlled to be changed, and the flow of the refrigerant between the second heat exchanger and the centrifugal compressor 1 is adjusted.

Optionally, when the chiller starts to operate, the first air supply pipeline of the air bearing 12 is closed, and the second air supply pipeline of the air bearing 12 is opened. That is, when the water chiller is started up, the system is unstable in operation, at this time, the first electromagnetic valve 41 is closed, the second electromagnetic valve 42 is opened, the gas compression device 6 compresses part of the gas led out by the first heat exchanger 5, and then the gas is conveyed to the superheating device 2 to be heated, so that liquid drops in the gas are reduced, the gas reaches a preset gas supply pressure or gas supply temperature, or the pressure of the gas in the superheating device 2 is stabilized, stable saturated gas or superheated gas is provided for the air bearing 12, and the stability of the operation of the centrifugal compressor 1 is ensured.

Optionally, after the water chiller runs stably, the first air supply pipeline of the air bearing 12 is closed and opened, and the second air supply pipeline of the air bearing 12 is closed. That is, after the system of the water chilling unit operates stably, the first electromagnetic valve 41 is opened, the second electromagnetic valve 42 is closed, so that a part of the gas discharged from the refrigerant compression cavity 11 is led to the superheating device 2 through the first electromagnetic valve 41 to be heated, and liquid drops in the gas are reduced; when the first sensor 71 detects that the pressure and/or the temperature of the gas are lower than the preset value of the gas supply of the air bearing 12, and/or the second sensor 73 detects that the pressure and/or the temperature of the gas are lower than the preset value of the gas supply of the air bearing 12, the control device controls the heating module to be started, the pressure and/or the temperature of the gas are increased through heating, and the control device judges the heating module to be started or closed according to the pressure and/or temperature signals detected by the first sensor 71 and/or the second sensor 73 in real time; when the first sensor 71 and/or the second sensor 73 detect that the pressure of the gas is higher than the preset value of the gas supply of the air bearing 12, the heating module is not started. Therefore, after the system runs stably, the first air supply pipeline of the air bearing 12 is opened to supply air to the air bearing, so that the power consumption of the air compression device 6 is reduced, and the energy consumption of the water chilling unit is reduced.

Alternatively, after the operation of the chiller is stable, the first air supply pipeline of the air bearing 12 supplies air, and when the flow signal detected by the first flow meter 72 and/or the second flow meter 74 cannot meet the air supply flow of the air bearing 12, the control device may control the opening degree of the first electromagnetic valve 41 to change the flow of the first air supply pipeline; alternatively, the control device controls the second solenoid valve 42 to open the second air supply pipeline of the air bearing 12, and adjusts the opening degrees of the second solenoid valve 42 and the third solenoid valve 43 to adjust the flow rate of the second air supply pipeline, so as to ensure the air supply amount of the air bearing 12.

Alternatively, the control device adjusts the opening and closing of the overheating device 2 or adjusts the opening degree of the first solenoid valve 41, the second solenoid valve 42 and the third solenoid valve 43 according to the data detected by the first sensor 71, the first flow meter 72 and/or the second sensor 73 and the second flow meter in real time. Therefore, the centrifugal compressor 1 can run more stably, and the water chilling unit is more efficient and energy-saving.

Fig. 2 is a schematic structural diagram of another water chilling unit provided in the embodiment of the present disclosure. As shown in fig. 2, the gas compressing device 6 may be replaced with a gas heating device, and the effects achieved in the above embodiments may be achieved.

The above description and drawings sufficiently illustrate embodiments of the disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. The embodiments of the present disclosure are not limited to the structures that have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.