阅读说明：本技术 压缩机用气体轴承的供气系统、操作方法及制冷系统 (Gas bearing gas supply system for compressor, operation method and refrigeration system ) 是由 刘华 张治平 周宇 陈玉辉 于 2020-09-02 设计创作，主要内容包括：本发明涉及一种压缩机用气体轴承的供气系统、操作方法及制冷系统。其中,压缩机用气体轴承的供气系统包括：第一压缩机及其所在的制冷循环路径,气体轴承设于第一压缩机；供气罐；进气管,连通供气罐与制冷循环路径的第一部位；出气管,连通供气罐与第一压缩机；回气管,连通供气罐与制冷循环路径的第二部位；以及调节阀,设于回气管,调节阀的开度可调,以调节回气管内的气体流量；其中,在第一压缩机的正常稳定工作状态下,第一部位处的气体压力大于第二部位处的气体压力。本发明通过回气管上的调节阀调节供气罐内的气体压力,以向气体轴承提供稳定压力的气态冷媒,结构简单,操作控制方便,可靠性高。(The invention relates to a gas supply system of a gas bearing for a compressor, an operation method and a refrigeration system. Wherein, the air supply system of gas bearing for the compressor includes: the air compressor comprises a first compressor and a refrigeration circulation path where the first compressor is located, and an air bearing is arranged on the first compressor; an air supply tank; an air supply pipe for communicating the air supply tank with a first portion of the refrigeration circulation path; the air outlet pipe is communicated with the air supply tank and the first compressor; a gas return pipe for communicating the gas supply tank with a second part of the refrigeration circulation path; the regulating valve is arranged in the gas return pipe, and the opening degree of the regulating valve is adjustable so as to regulate the gas flow in the gas return pipe; wherein, under the normal steady operation state of the first compressor, the gas pressure at the first position is greater than the gas pressure at the second position. The gas pressure in the gas supply tank is adjusted through the adjusting valve on the gas return pipe so as to provide the gas refrigerant with stable pressure for the gas bearing, and the gas bearing has the advantages of simple structure, convenience in operation and control and high reliability.)

1. An air supply system for a gas bearing for a compressor, comprising:

the air compressor comprises a first compressor (1) and a refrigeration circulation path where the first compressor is located, wherein a gas bearing is arranged on the first compressor (1);

an air supply tank (3);

an intake pipe (4) communicating the air supply tank (3) with a first portion of the refrigeration circulation path, the intake pipe (4) being configured to guide the gaseous refrigerant in the refrigeration circulation path to the air supply tank (3);

an outlet pipe (5) communicating the gas supply tank (3) with the first compressor (1), the outlet pipe (5) being configured to guide a gaseous refrigerant in the gas supply tank (3) to the gas bearing to supply gas to the gas bearing;

a gas return pipe (6) that communicates the gas supply tank (3) with a second portion of the refrigeration circulation path, the gas return pipe (6) being configured to guide the gaseous refrigerant in the gas supply tank (3) to the refrigeration circulation path; and

the adjusting valve (61) is arranged on the gas return pipe (6), and the opening degree of the adjusting valve (61) can be adjusted so as to adjust the gas flow in the gas return pipe (6);

wherein, in a normal steady operation state of the first compressor (1), the gas pressure at the first location is greater than the gas pressure at the second location.

2. The gas supply system for the gas bearing of the compressor as claimed in claim 1, comprising a second compressor (2), wherein the gas inlet pipe (4) comprises a first pipe (41), the second compressor (2) is disposed on the first pipe (41), and a gas outlet end of the second compressor (2) is communicated with the gas supply tank (3), and the second compressor (2) is configured to pressurize the gaseous refrigerant in the first pipe (41) and send the pressurized gaseous refrigerant to the gas supply tank (3).

3. The gas supply system for a gas bearing for a compressor as claimed in claim 2, comprising a first direction control element (411), wherein the first direction control element (411) is provided to the first pipe (41) between a discharge end of the second compressor (2) and the gas supply tank (3), and wherein the first direction control element (411) is configured to control a flow of a gaseous refrigerant from the second compressor (2) to the gas supply tank (3).

4. The gas supply system for a gas bearing for a compressor according to claim 2, comprising a second direction control element (421), wherein the gas inlet pipe (4) comprises a second pipe (42), the second pipe (42) is connected in parallel with the first pipe (41), the second direction control element (421) is provided to the second pipe (42), and the second direction control element (421) is configured to control a flow of the gaseous refrigerant from the first portion of the refrigeration cycle path to the gas supply tank (3).

5. The gas supply system for a gas bearing for a compressor as claimed in claim 2, wherein said second compressor (2) is configured to be started before, immediately after, or in an unstable operation state of said first compressor (1) to pressurize the gaseous refrigerant in said first pipe (41) and send it to said gas supply tank (3).

6. The gas bearing supply system for a compressor according to claim 1, comprising a condenser (7), wherein the condenser (7) is provided in the refrigeration circulation path, and the first portion comprises a portion on the condenser (7).

7. The gas bearing supply system for a compressor according to claim 1, comprising an evaporator (8), wherein said evaporator (8) is provided in said refrigeration circulation path, and wherein said second portion comprises a portion on said evaporator (8).

8. The gas bearing supply system for a compressor according to claim 1, comprising a flash tank (10), said flash tank (10) being provided in said refrigeration circulation path, said second location comprising a location on said flash tank (10).

9. The gas supply system for a gas bearing for a compressor according to claim 1, comprising a first pressure sensor (11) and a second pressure sensor (31), wherein the first pressure sensor (11) is provided at the first compressor (1) and configured to detect an internal pressure of the first compressor (1), and the second pressure sensor (31) is provided at the gas supply tank (3) and configured to detect a gas pressure inside the gas supply tank (3).

10. The gas bearing supply system for a compressor as claimed in claim 6, comprising a third pressure sensor (71), wherein said third pressure sensor (71) is provided to said condenser (7) and is configured to detect an internal pressure of said condenser (7).

11. A refrigerating system comprising the gas supply system for a gas bearing for a compressor according to any one of claims 1 to 10.

12. A method for operating a gas supply system for a gas bearing for a compressor according to claim 1, comprising:

setting a differential pressure value P_X＝P₁-P₂(ii) a Wherein, P₁The value of the gas pressure in the gas supply tank (3); p₂Is the internal pressure value of the first compressor (1);

when P is present_X<P_TReducing the opening degree of the regulating valve (61);

when P is present_X>P_TIncreasing the opening degree of the regulating valve (61);

when P is present_X＝P_TMaintaining the opening degree of the regulating valve (61) unchanged;

wherein, P_TA target gas pressure value required for normal and stable operation of the gas bearing of the first compressor (1).

13. The method for operating a gas supply system for a gas bearing for a compressor according to claim 12,

the gas bearing gas supply system for the compressor comprises a second compressor (2), the gas inlet pipe (4) comprises a first pipe (41) and a second pipe (42) which are connected in parallel, and the second compressor (2) is arranged on the first pipe (41);

at P₃-P₂<P_minWhen the second compressor (2) is started, and according to P_XAnd P_TAdjusting the opening of the regulating valve 61;

at P₃-P₂≥P_minWhile the second compressor (2) is turned off and according to P_XAnd P_TAdjusting the opening of the regulating valve (61);

wherein, P₃Is the gas pressure at the first location; p_minMinimum value of gas pressure, P, required for the normal and stable operation of the gas bearing of the first compressor (1)_min≤P_T。

14. The method for operating a gas supply system for a gas bearing for a compressor according to claim 13,

p is in the state that the first compressor (1) is just started, or the first compressor (1) is closed or the first compressor (1) is in the unstable working state₃-P₂<P_min；

In the stable working state of the first compressor (1), P₃-P₂≥P_min。

Technical Field

The invention relates to the field of refrigeration systems, in particular to a gas supply system for a gas bearing for a compressor, an operation method and a refrigeration system.

Background

Centrifugal chiller units are commonly used in various building air conditioners, and oil-lubricated bearings and electromagnetic bearings (i.e., magnetic suspension bearings) are generally adopted as compressor bearings of the centrifugal chiller units at present.

The use of oil to lubricate the bearings requires an additional oil supply system, increasing the complexity of the system. Lubricating oil leaks into a refrigerating system in the running process of the compressor and is fused with a refrigerant, so that a lubricating oil return system is needed for periodic oil return. The oil-lubricated bearing also has the problems of mechanical friction, reduced mechanical efficiency, reduced unit performance and the like.

The centrifugal compressor adopting the electromagnetic bearing suspends the bearing by magnetic force, an electric control system of the magnetic suspension bearing is complex and large in size, the requirement on the processing consistency of the bearing is high, the shock resistance of the system is poor, and in addition, extra abnormal power-off protection measures are required.

At present, gas bearings (gas suspension bearings) are beginning to be applied in centrifugal compressors, which support the rotating shaft by gas force, with the following advantages: 1) compared with a compressor using an oil lubricating bearing, the compressor does not need an oil supply system, an oil return system, a cold oil system and a filtering system, has no lubricating oil leakage risk, and saves the lubricating oil maintenance work; when the bearing works, the bearing is in a suspension state, no friction exists, mechanical loss is reduced, and unit performance is improved; 2) compared with a compressor adopting a magnetic suspension bearing, the compressor does not need a complex electric control system and an abnormal power-off protection system.

However, the gas bearing needs external gas supply when working, so that the problem of unstable gas supply for the gas bearing exists.

Disclosure of Invention

Some embodiments of the invention provide a gas bearing gas supply system for a compressor, an operation method and a refrigeration system, which are used for relieving the problem of unstable gas supply.

Some embodiments of the present invention provide an air supply system for a gas bearing for a compressor, including:

the gas bearing is arranged on the first compressor;

an air supply tank;

an inlet pipe communicating the air supply tank with a first portion of the refrigeration circulation path, the inlet pipe configured to guide a gaseous refrigerant in the refrigeration circulation path to the air supply tank;

an air outlet pipe communicating the air supply tank with the first compressor, the air outlet pipe being configured to guide a gaseous refrigerant in the air supply tank to the gas bearing to supply air to the gas bearing;

a gas return pipe communicating the gas supply tank with a second portion of the refrigeration circulation path, the gas return pipe being configured to guide the gaseous refrigerant in the gas supply tank to the refrigeration circulation path; and

the regulating valve is arranged in the gas return pipe, and the opening degree of the regulating valve can be adjusted so as to regulate the gas flow in the gas return pipe;

wherein, under normal steady operation of the first compressor, the gas pressure at the first location is greater than the gas pressure at the second location.

In some embodiments, the gas supply system for a gas bearing for a compressor includes a second compressor, the gas inlet pipe includes a first pipe, the second compressor is disposed in the first pipe, and a gas outlet end of the second compressor is communicated with the gas supply tank, and the second compressor is configured to pressurize a gaseous refrigerant in the first pipe and send the pressurized gaseous refrigerant to the gas supply tank.

In some embodiments, the gas bearing gas supply system for a compressor includes a first direction control element disposed in the first pipe between a discharge end of the second compressor and the gas supply tank, the first direction control element configured to control a flow of a gaseous refrigerant from the second compressor to the gas supply tank.

In some embodiments, the gas bearing gas supply system for a compressor includes a second directional control element, the gas inlet pipe includes a second pipe connected in parallel with the first pipe, the second directional control element is disposed in the second pipe, and the second directional control element is configured to control a flow of a gaseous refrigerant from a first portion of the refrigeration cycle path to the gas supply tank.

In some embodiments, the second compressor is configured to start before starting, in a starting state, or in an unstable operating state, so as to pressurize the gaseous refrigerant in the first pipe and send the pressurized gaseous refrigerant to the gas supply tank.

In some embodiments, the gas bearing gas supply system for a compressor includes a condenser disposed in the refrigeration cycle path, and the first location includes a location on the condenser.

In some embodiments, the gas bearing air supply system for a compressor includes an evaporator disposed in the refrigeration cycle path, and the second location includes a location on the evaporator.

In some embodiments, the gas bearing for compressor supply system includes a flash tank disposed in the refrigeration cycle path, and the second location includes a location on the flash tank.

In some embodiments, the gas supply system for a gas bearing for a compressor includes a first pressure sensor provided in the first compressor and configured to detect an internal pressure of the first compressor, and a second pressure sensor provided in the gas supply tank and configured to detect a gas pressure in the gas supply tank.

In some embodiments, the gas bearing gas supply system for a compressor includes a third pressure sensor disposed at the condenser and configured to detect an internal pressure of the condenser.

Some embodiments of the present invention provide a refrigeration system including the gas bearing supply system for a compressor described above.

Some embodiments of the present invention provide a method of operating an air supply system for a gas bearing for a compressor, including:

setting a differential pressure value P_X＝P₁-P₂(ii) a Wherein, P₁The value of the gas pressure in the gas supply tank is; p₂Is the internal pressure value of the first compressor;

when P is present_X<P_TReducing the opening degree of the regulating valve;

when P is present_X>P_TIncreasing the opening degree of the regulating valve;

when P is present_X＝P_TMaintaining the opening of the regulating valve unchanged;

wherein, P_TA target gas pressure value required for normal and stable operation of the gas bearing of the first compressor.

In some embodiments, the gas bearing gas supply system for the compressor comprises a second compressor, the gas inlet pipe comprises a first pipe and a second pipe which are connected in parallel, and the second compressor is arranged in the first pipe;

at P₃-P₂<P_minWhen the second compressor is started, and according to P_XAnd P_TAdjusting the opening of the regulating valve 61;

at P₃-P₂≥P_minWhen the second compressor is turned off, and according to P_XAnd P_TAdjusting the opening of the regulating valve;

wherein, P₃Is the gas pressure at the first location; p_minMinimum value of gas pressure, P, required for the normal and stable operation of the gas bearing of the first compressor_min≤P_T。

In some embodiments, P is when the first compressor is in a state of just starting, or the first compressor is off, or the first compressor is in an unstable operating state₃-P₂<P_min；

In the stable working state of the first compressor, P₃-P₂≥P_min。

Based on the technical scheme, the invention at least has the following beneficial effects:

in some embodiments, the inlet pipe directs the gaseous refrigerant in the refrigeration cycle path to the gas supply tank, and the outlet pipe directs the gaseous refrigerant in the gas supply tank to the gas bearing to supply gas to the gas bearing; the gaseous refrigerant of muffler in with the air feed tank is led back to the refrigeration circulation route, and adjust the gas pressure in the air feed tank through the regulating valve on the muffler, with the gaseous refrigerant that provides stable pressure to gas bearing, moreover, the steam generator is simple in structure, operation control is convenient, compare in the cooperation work of a plurality of valves, the reliability of single valve control is higher, and unnecessary gaseous refrigerant in the air feed tank returns first compressor and the refrigeration circulation route at place through the muffler, can improve the performance of first compressor.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a schematic diagram of a refrigeration system provided in accordance with some embodiments of the present invention.

Fig. 2 is a schematic diagram of a refrigeration system provided in accordance with further embodiments of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be taken as limiting the scope of the present invention.

The gas bearing supports the rotating shaft by utilizing gas force, and a set of gas supply system with stable and reliable gas supply is needed to supply gas to the gas bearing in order to ensure the normal and stable work of the gas bearing. After the gas pressure provided by the gas supply system meets the gas pressure required by the normal and stable work of the gas bearing, the rotating shaft of the compressor can be changed into a suspension state, and the motor of the compressor rotates to run. The stable and sufficient air supply pressure of the air bearing is a precondition for the normal and stable operation of the compressor.

As shown in fig. 1, some embodiments provide an air supply system for a gas bearing for a compressor, including: the first compressor 1 and the refrigeration cycle path in which it is located, the gas supply tank 3, the gas inlet pipe 4, the gas outlet pipe 5, the gas return pipe 6 and the regulating valve 61.

The gas bearing is arranged in the first compressor 1 and used for supporting a rotating shaft in the first compressor 1. The gas supply tank 3 is configured to supply gas to the gas bearing in the first compressor 1 so that the gas bearing operates normally and stably.

The intake pipe 4 communicates the air supply tank 3 with a first portion of the refrigeration circulation path, and the intake pipe 4 is configured to guide the gaseous refrigerant in the refrigeration circulation path to the air supply tank 3.

The gas outlet pipe 5 communicates the gas supply tank 3 with the first compressor 1, and the gas outlet pipe 5 is configured to guide the gaseous refrigerant in the gas supply tank 3 to the gas bearing to supply gas to the gas bearing.

The gas return pipe 6 communicates the gas supply tank 3 with a second portion of the refrigeration circulation path, and the gas return pipe 6 is arranged to guide the gaseous refrigerant in the gas supply tank 3 to the refrigeration circulation path.

The adjusting valve 61 is arranged on the gas return pipe 6, and the opening degree of the adjusting valve 61 is adjustable so as to adjust the gas flow in the gas return pipe 6. Optionally, the regulating valve 61 regulates the opening between 0% and 100%.

Wherein the gas pressure at the first location is higher than the gas pressure at the second location in normal steady operation of the first compressor 1.

In some embodiments, the gas inlet pipe 4 guides the gaseous refrigerant in the refrigeration cycle path to the gas supply tank 3, the gas outlet pipe 5 guides the gaseous refrigerant in the gas supply tank 3 to the gas bearing to supply gas to the gas bearing, the gas return pipe 6 guides the gaseous refrigerant in the gas supply tank 3 back to the refrigeration cycle path, and the gas return pipe 6 is provided with the adjusting valve 61 with an adjustable opening degree. In the above process, if the pressure of the gaseous refrigerant supplied by the gas supply tank 3 is greater than the gas pressure required by the normal and stable operation of the gas bearing, the opening of the regulating valve 61 is increased by adjustment to reduce the pressure of the gaseous refrigerant supplied by the gas supply tank 3; if the pressure of the gaseous refrigerant provided by the gas supply tank 3 is less than the gas pressure required by the normal and stable operation of the gas bearing, the opening degree of the regulating valve 61 is reduced by regulation, so that the pressure of the gaseous refrigerant provided by the gas supply tank 3 is increased; if the pressure of the gaseous refrigerant supplied from the gas supply tank 3 is equal to the gas pressure required for the normal and stable operation of the gas bearing, the opening degree of the regulating valve 61 is maintained. That is to say, just can adjust the gas pressure in the gas supply tank 3 through the governing valve 61 on the muffler 6 to provide the gaseous refrigerant of stable pressure to gas bearing, simple structure, operation control is convenient, compares in the cooperation work of a plurality of valves, and the reliability of single valve control is higher, and the refrigeration circulation route that redundant gaseous refrigerant passes through muffler 6 and returns first compressor 1 and its place in the gas supply tank 3, can improve first compressor 1's performance.

In some embodiments, the air supply system for the gas bearing for the compressor includes a second compressor 2, the air inlet pipe 4 includes a first pipe 41, the second compressor 2 is disposed on the first pipe 41, and the air outlet end of the second compressor 2 is communicated with the air supply tank 3, and the second compressor 2 is configured to pressurize the gaseous refrigerant in the first pipe 41 and send the pressurized gaseous refrigerant to the air supply tank 3.

Under the condition that the gas pressure in the refrigeration circulation path of the first compressor 1 does not reach the gas pressure required by the gas bearing, the gaseous refrigerant in the refrigeration circulation path of the first compressor 1 is pressurized by the second compressor 2 to meet the gas pressure required by the gas bearing, and the problem that the gas bearing is supplied with gas by insufficient pressure difference in a unit is solved.

The second compressor 2 is used for pressurizing the gaseous refrigerant in the refrigeration circulation path where the first compressor 1 is located, so that continuous and stable-pressure gas can be provided for the gas bearing, and the continuous and stable operation of the gas bearing is favorably ensured; and the gaseous refrigerant supplied to the gas bearing is pure, and is not easy to be doped with liquid refrigerant, so that the working reliability of the gas bearing is ensured.

The gas refrigerant in the refrigeration circulation path of the first compressor 1 is pressurized and supplied to the gas bearing through the second compressor 2, no liquid medium exists in the process, a throttling device, a gas-liquid separation device and the like are not required to be arranged, and the gas bearing refrigerating system is simple in structure and convenient to operate.

In some embodiments, the gas bearing supply system for a compressor includes a first direction control element 411, the first direction control element 411 is disposed on the first pipe 41 and located between the discharge end of the second compressor 2 and the gas supply tank 3, and the first direction control element 411 is configured to control a flow of a gaseous refrigerant from the second compressor 2 to the gas supply tank 3. By providing the first direction control element 411, the gaseous refrigerant in the air supply tank 3 is prevented from flowing backward to the second compressor 2.

Alternatively, the first directional control element 411 may comprise a directional control valve such as a check valve or a solenoid valve.

In some embodiments, the gas bearing gas supply system for the compressor includes a second direction control element 421, the gas inlet pipe 4 includes a second pipe 42, the second pipe 42 is connected in parallel with the first pipe 41, the second direction control element 421 is provided on the second pipe 42, and the second direction control element 421 is configured to control the flow of the gaseous refrigerant from the first portion of the refrigeration circulation path to the gas supply tank 3. By providing the second direction control member 421, the gaseous refrigerant in the air supply tank 3 is prevented from flowing backward to the refrigeration cycle path where the first compressor 1 is located.

Alternatively, the second directional control element 421 includes a directional control valve such as a check valve or a solenoid valve.

In some embodiments, the second compressor 2 is configured to be started before the first compressor 1 is started, in a start-up state, or in an unstable operation state, so as to pressurize the gaseous refrigerant in the first pipe 41 and send the pressurized gaseous refrigerant to the gas supply tank 3.

Before the first compressor 1 is started, the pressure of the gaseous refrigerant in the refrigeration circulation path where the first compressor 1 is located is low, and the working pressure required by the gas bearing cannot be achieved, and the gaseous refrigerant in the refrigeration circulation path where the first compressor 1 is located is pressurized and supplied to the gas bearing through the second compressor 2, so that the problem that the gas bearing is supplied with gas by insufficient pressure difference in a unit before the unit is started can be solved.

In the first compressor 1, in the state of starting, the pressure of the gaseous refrigerant in the refrigeration circulation path where the first compressor 1 is located is gradually increased, but the working pressure required by the gas bearing is still not reached, the gaseous refrigerant in the refrigeration circulation path where the first compressor 1 is located is pressurized and supplied to the gas bearing through the second compressor 2, and the problem that the gas bearing is supplied with gas by insufficient pressure difference in a unit can be solved.

In the unstable operation state of the first compressor 1, the pressure of the gaseous refrigerant in the refrigeration cycle path where the first compressor 1 is located may be unstable, and there may be a case where the required operating pressure of the gas bearing cannot be satisfied, and the gaseous refrigerant in the refrigeration cycle path where the first compressor 1 is located is pressurized and supplied to the gas bearing by the second compressor 2, so that a continuous and stable-pressure gas can be provided for the gas bearing.

In some embodiments, the air inlet pipe 4 includes a first pipe 41 and a second pipe 42 connected in parallel, the second compressor 2 is disposed in the first pipe 41, the second compressor 2 can selectively operate to provide a refrigerant to the air supply tank 3, the second pipe 42 is always communicated with the refrigeration circulation path where the first compressor 1 is located and the air supply tank 3, that is, a control mode that the second compressor 2 selectively supplies air and combines with a stable flow path is adopted, problems of frequent start and stop of the air supply system, liquid carrying in the air supply system and the like are avoided, the air supply is stable, and reliability of the operation of the air supply system and the unit is effectively improved.

In some embodiments, the gas bearing air supply system for a compressor comprises a condenser 7, the condenser 7 being provided in the refrigeration circulation path, the first location comprising a location on the condenser 7. Of course, the first location is not limited to the location on the condenser 7, and may include a discharge port of the first compressor 1, a pipe between the first compressor 1 and the condenser 7, or the like, that is, a component or a location containing a gaseous refrigerant in the refrigeration cycle path in which the first compressor 1 is located, or the like.

The first pipe 41 and the second pipe 42 communicate with a space in which the gaseous refrigerant inside the condenser 7 is located.

In some embodiments, the gas bearing air supply system for a compressor includes an evaporator 8, the evaporator 8 is provided in the refrigeration cycle path, and the second location includes a location on the evaporator 8.

In some embodiments, the compressor gas bearing supply system includes a flash tank 10, the flash tank 10 is disposed in the refrigeration cycle path, and the second location includes a location on the flash tank 10.

The gas return pipe 6 is communicated with the space where the gaseous refrigerant in the evaporator 8 or the flash evaporator 10 is located.

Of course, the second location is not limited to the location on the evaporator 8 or the flash tank 10, and may include the air inlet of the first compressor 1, or a pipe between the first compressor 1 and the evaporator 8, that is, a location on the refrigeration cycle path where the first compressor 1 is located, as long as it is satisfied that the gas pressure at the first location is greater than the gas pressure at the second location in the normal steady operation state of the first compressor 1.

In some embodiments, the gas supply system for a gas bearing for a compressor includes a first pressure sensor 11 and a second pressure sensor 31, the first pressure sensor 11 is provided to the first compressor 1, and the first pressure sensor 11 is configured to detect an internal pressure of the first compressor 1. The second pressure sensor 31 is provided in the gas supply tank 3, and the second pressure sensor 31 is configured to detect the gas pressure in the gas supply tank 3.

The internal pressure of the first compressor 1 is the pressure for limiting the normal stable operation of the gas bearing, the gas pressure provided by the gas supply tank 3 needs to overcome the internal pressure of the first compressor 1, the gravity of the rotating shaft of the compressor, the radial force received in the rotating process of the rotating shaft and the like, so that the gas bearing can normally and stably operate, and when the gas bearing normally and stably operates, the rotating shaft of the compressor becomes a suspension state, and the compressor normally and stably operates.

In some embodiments, the gas bearing gas supply system for a compressor includes a third pressure sensor 71, the third pressure sensor 71 is provided to the condenser 7, and the condenser 7 is configured to detect an internal pressure of the condenser 7.

In some embodiments, the first compressor 1 comprises a centrifugal compressor.

In some embodiments, the second compressor 2 comprises a compressor with a relatively small volume flow, such as a scroll compressor, a rotary shaft compressor, or a piston compressor.

In some embodiments, the volume flow of the first compressor 1 is greater than the volume flow of the second compressor 2.

In some embodiments, a first filter 412 is disposed on the first tube 41. A second filter 422 is provided on the second tube 42. The outlet pipe 5 is provided with a third filter 51.

In some embodiments, no regulating valve is needed to be arranged on the first pipe 41, the second pipe 42 and the air outlet pipe 5, and the regulation of the pressure in the air supply tank 3 can be realized only by arranging the regulating valve 61 on the air return pipe 6, so that a gaseous refrigerant with stable pressure is provided for the gas bearing.

Some embodiments provide a refrigeration system including the gas bearing gas supply system for a compressor described above.

The refrigeration system includes a gas bearing gas supply system for the compressor, which includes the first compressor 1, and a refrigeration circulation path in which the first compressor 1 is located.

In some embodiments, as shown in fig. 1, the refrigeration cycle path in which the first compressor 1 is located also includes the first compressor 1, and further includes a condenser 7, an evaporator 8, a throttle valve 9, and the like.

The cycle process of the refrigeration cycle path in which the first compressor 1 is located is as follows: first compressor 1-condenser 7-throttle valve 9-evaporator 8-first compressor 1.

In some embodiments, as shown in fig. 2, the refrigeration cycle path in which the first compressor 1 is located also includes the first compressor 1, and further includes a condenser 7, an evaporator 8, a first throttle valve 91, a second throttle valve 92, a flash tank 10, and the like.

The cycle process of the refrigeration cycle path in which the first compressor 1 is located is as follows: first compressor 1-condenser 7-first throttle valve 91-flash tank 10-second throttle valve 92-evaporator 8-first compressor 1. Wherein, the flash tank 10 is still connected with the first compressor 1, and the air and the enthalpy of the first compressor 1 are increased.

The first compressor 1 comprises a two-stage compressor, the two-stage compressor comprises a low-pressure stage part 12 and a high-pressure stage part 13, and the flash tank 10 is communicated between the low-pressure stage part 12 and the high-pressure stage part 13 of the two-stage compressor through a pipeline.

In some embodiments, the refrigeration system comprises an air conditioning refrigeration system. The refrigerating system has a refrigerating function and a heating function. The refrigeration cycle path in which the first compressor 1 is located includes a refrigeration path and a heating path.

Some embodiments provide a method of operating a gas supply system for a gas bearing for a compressor, comprising:

setting a differential pressure value P_X＝P₁-P₂(ii) a Wherein, P₁The value of the gas pressure in the gas supply tank 3; p₂Is the internal pressure value of the first compressor 1;

when P is present_X<P_TDecreasing the opening of the regulating valve 61;

when P is present_X>P_TIncreasing the opening of the regulating valve 61;

when P is present_X＝P_TMaintaining the opening of the regulating valve 61 unchanged;

wherein, P_TA target value of gas pressure required for normal and stable operation of the gas bearing of the first compressor 1.

In some embodiments, the gas bearing supply system for a compressor comprises a second compressor 2, the gas inlet pipe 4 comprises a first pipe 41 and a second pipe 42 connected in parallel, and the second compressor 2 is arranged on the first pipe 41.

At P₃-P₂<P_minWhen the second compressor (2) is started, and according to P_XAnd P_TAdjusting the opening of the regulating valve 61;

P₃-P₂≥P_minwhile the second compressor (2) is turned off, andaccording to P_XAnd P_TAdjusting the opening of the regulating valve (61);

wherein, P₃Is the gas pressure at the first location; p_minMinimum value of gas pressure, P, required for the normal and stable operation of the gas bearing of the first compressor (1)_min≤P_T。

In some embodiments, P is when the first compressor 1 is in a state of just starting, or the first compressor 1 is off, or the first compressor 1 is in an unstable operating state₃-P₂<P_min。

In the first compressor 1 in a stable operating state, P₃-P₂≥P_min。

In some embodiments, a first pipe 41 and a second pipe 42 are connected in parallel, wherein the second compressor 2 is disposed in the first pipe 41 and selectively supplies gas to the gas supply tank 3, the second pipe 42 continuously supplies gas to the gas supply tank 3, the gas outlet pipe 5 supplies gas to the gas bearing, and the opening degree of the pressure stabilizing valve 61 on the gas return pipe 6 is adjustable to adjust the gas pressure in the gas supply tank 3, so that gaseous refrigerant with stable pressure can be provided for the gas bearing through the cooperation of the components, and the reliable and stable operation of the unit is facilitated.

In the following, an embodiment of the gas bearing supply system for a compressor and the refrigeration system thereof is described, and in this embodiment, the gas bearing supply system for a compressor and the refrigeration system thereof include a first compressor 1, a second compressor 2, a gas supply tank 3, a first pipe 41, a second pipe 42, a gas outlet pipe 5, a gas return pipe 6, a pressure maintaining valve 61, a condenser 7, an evaporator 8, a throttle valve 9, and the like.

The first compressor 1 is provided with a first pressure sensor 11, and the first pressure sensor 11 is used for detecting the internal pressure of the first compressor 1. The gas supply tank 3 is provided with a second pressure sensor 31, and the second pressure sensor 31 is used for detecting the gas pressure in the gas supply tank 3.

The exhaust port of the first compressor 1 is connected to the inlet of the condenser 7, and the condenser 7 is provided with a third pressure sensor 71, and the third pressure sensor 71 is used for detecting the internal pressure of the condenser 7. The outlet of the condenser 7 is connected with the inlet of the throttle valve 9, the outlet of the throttle valve 9 is connected with the inlet of the evaporator 8, the evaporator 8 is provided with a fourth pressure sensor 81, the fourth pressure sensor 81 is used for detecting the internal pressure of the evaporator 8, and the outlet of the evaporator 8 is connected with the air inlet of the first compressor 1.

An inlet of the first pipe 41 is connected to the condenser 7, an outlet of the first pipe 41 is connected to the air supply tank 3, and the second compressor 2, the first direction control element 411 and the first filter 412 are provided on the first pipe 41.

An inlet of the second pipe 42 is connected to the condenser 7, an outlet of the second pipe 42 is connected to the air supply tank 3, and a second filter 422 and a second direction control member 421 are provided on the second pipe 42.

An inlet of the air outlet pipe 5 is connected with the air supply tank 3, and an outlet of the air outlet pipe 5 is connected with the first compressor 1 and used for supplying air to the air bearing in the first compressor 1.

The inlet of the air return pipe 6 is connected with the air supply tank 3, the outlet of the air return pipe 6 is connected with the evaporator 8, and the pressure stabilizing valve 61 is arranged on the air return pipe 6 and used for adjusting the air flow in the air return pipe 61.

Setting a differential pressure value P_X＝P₁-P₂(ii) a Wherein, P₁The value of the gas pressure in the gas supply tank 3; p₂Is the internal pressure value of the first compressor 1.

Setting P_TAnd P_min，P_TA target value of gas pressure required for normal and stable operation of the gas bearing of the first compressor 1. P_minThe minimum gas pressure required for the normal and stable operation of the gas bearings of the first compressor 1. P_T≥P_min。

The cross-sectional area of the air holes on the gas bearing is constant, so the air supply flow passing through the bearing is equal to P_XIs related to the size of P_XThe larger the value, the larger the supply air flow, and vice versa, according to P_XAnd P_TAdjusting the opening of the regulating valve 61 to further regulate P_XThe value of the air bearing is adjusted.

When P is present_X＝P_TIndicating that the gas flow rate, P, required for normal stable operation of the gas bearing can be provided_XThe more stable the gas supply amountThe more stable the unit operation, the more stable the opening of the regulating valve 61 is maintained.

When P is present_X<P_TDecreasing the opening of the regulating valve 61 for increasing P_XThe value is obtained.

When P is present_X>P_TIncreasing the opening of the regulating valve 61 for decreasing P_XThe value is obtained.

In the running process of the unit, the air supply system comprises an air supply mode I and an air supply mode II according to different states of the unit.

The first air supply mode: when the unit is in a starting process state, a shutdown process state, and an abnormal stable working state, the condenser 7 cannot meet the gas supply of the gas bearing, or when the internal pressure P of the condenser 7 is high₃With the internal pressure P of the first compressor 1₂Is less than P_minNamely: p₃-P₂<P_minThe condenser 7 can not meet the gas supply of the gas bearing, the second compressor 2 is started, and the gas bearing can be started according to P_XAnd P_TThe opening degree of the regulating valve 61 is adjusted.

That is, in the first air supply mode, when the second compressor 2 is not turned on, the pressure of the air in the air supply tank 3 may be smaller than, larger than, or equal to the internal pressure value of the condenser 7. However, the second direction control element 21 is provided in the second pipe 42 between the condenser 7 and the air supply tank 3, that is, the refrigerant flows only from the condenser 7 to the air supply tank 3 and does not flow from the air supply tank 3 to the condenser 7. When the second compressor 2 is turned on for a while, the internal pressure of the condenser 7 is lower than the internal pressure of the gas supply tank 3.

And (2) air supply mode II: when the internal pressure P of the condenser 7 is higher₃With the internal pressure P of the first compressor 1₂Is greater than or equal to P_minNamely: p₃-P₂≥P_minThe condenser 7 can now be supplied with gas from the gas bearing, the second compressor 2 is switched off, and this can be done according to P_XAnd P_TThe opening degree of the regulating valve 61 is adjusted.

In the second air supply mode, the internal pressure of the air supply tank 3 is equal to or lower than the internal pressure of the condenser 7.

Through the above-mentioned mutual cooperation of second compressor 2 and governing valve 61, the problem that frequently opens and stops does not exist in second compressor 2, can realize the gas bearing continuous stable air feed, guarantees the reliable steady operation of unit.

In the description of the present invention, it should be understood that the terms "first", "second", "third", etc. are used to define the components, and are used only for the convenience of distinguishing the components, and if not otherwise stated, the terms have no special meaning, and thus, should not be construed as limiting the scope of the present invention.

Furthermore, the technical features of one embodiment may be combined with one or more other embodiments advantageously without explicit negatives.

Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and not to limit the same; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.