阅读说明：本技术 气悬浮轴承供气系统、供气方法及离心式冷水机组 (Air supply system and method for air suspension bearing and centrifugal water chilling unit ) 是由 梁湖 周宇 刘贤权 黄成武 于 2020-07-06 设计创作，主要内容包括：本发明提供一种气悬浮轴承供气系统、供气方法及离心式冷水机组,气悬浮轴承供气系统包括：气悬浮压缩机及其所在的冷媒循环回路；第一供气回路,第一供气回路的进液口连接于冷媒循环回路的取液口,并从取液口取液,第一供气回路的出气口连接至气悬浮压缩机；第一供气回路包括补液罐、供气罐,补液罐、供气罐的安装高度低于取液口,冷媒循环回路内的冷媒能够在重力作用下从取液口流入第一供气回路。本发明的气悬浮轴承供气系统,适用于采用气悬浮轴承的离心冷水机组,通过将取液口、补液罐、供气罐的安装高度不同,借助重力和连通器原理,实现对气悬浮轴承持续稳定的供气,保证机组可靠稳定运行。(The invention provides an air supply system and an air supply method for an air suspension bearing and a centrifugal water chilling unit, wherein the air supply system for the air suspension bearing comprises: the air suspension compressor and a refrigerant circulation loop in which the air suspension compressor is arranged; a liquid inlet of the first gas supply loop is connected to a liquid taking port of the refrigerant circulation loop and takes liquid from the liquid taking port, and a gas outlet of the first gas supply loop is connected to the gas suspension compressor; the first air supply loop comprises a liquid replenishing tank and an air supply tank, the installation height of the liquid replenishing tank and the installation height of the air supply tank are lower than that of the liquid taking port, and the refrigerant in the refrigerant circulation loop can flow into the first air supply loop from the liquid taking port under the action of gravity. The air supply system for the air suspension bearing is suitable for a centrifugal water chilling unit adopting the air suspension bearing, realizes continuous and stable air supply for the air suspension bearing by means of gravity and a communicating vessel principle through different installation heights of the liquid taking port, the liquid supplementing tank and the air supply tank, and ensures reliable and stable operation of the unit.)

1. An air suspension bearing air supply system, comprising:

the air suspension compressor (1) and a refrigerant circulation loop in which the air suspension compressor is arranged;

a liquid inlet of the first gas supply loop (2) is connected to a liquid taking port of the refrigerant circulation loop and takes liquid from the liquid taking port, and a gas outlet of the first gas supply loop (2) is connected to the gas suspension compressor (1);

the first air supply loop (2) comprises a liquid replenishing tank (3) and an air supply tank (4), the installation heights of the liquid replenishing tank (3) and the air supply tank (4) are lower than the liquid taking port, and a refrigerant in the refrigerant circulation loop can flow into the first air supply loop (2) from the liquid taking port under the action of gravity.

2. The air supply system for the air suspension bearing according to claim 1, further comprising a second air supply loop (5), wherein the second air supply loop (5) is arranged between a condenser (8) of the refrigerant circulation loop and the air supply tank (4) in the first air supply loop (2), and a check valve (6) from the condenser (8) to the air supply tank (4) is arranged on the second air supply loop (5).

3. The air supply system for the air suspension bearing as recited in claim 1, wherein the refrigerant circulation loop comprises an evaporator (7), the liquid taking port is arranged in a liquid area of the evaporator (7), and the installation heights of the liquid replenishing tank (3) and the air supply tank (4) are lower than that of the evaporator (7).

4. The air supply system for the air suspension bearing as claimed in claim 3, wherein the height from the lowest point of the shell of the evaporator (7) to the ground is h1, the height from the lowest point of the shell of the liquid replenishing tank (3) to the ground is h2, and the height from the lowest point of the air supply tank (4) to the ground is h3, so that h1 > h2 > h3 is satisfied.

5. The air supply system for the air suspension bearing as claimed in claim 1, wherein the refrigerant circulation loop comprises a condenser (8), the liquid taking port is arranged in a liquid area of the condenser (8), and the installation heights of the liquid replenishing tank (3) and the air supply tank (4) are lower than that of the condenser (8).

6. The air supply system for the air suspension bearing as claimed in claim 5, wherein the height from the lowest point of the shell of the condenser (8) to the ground is h5, the height from the lowest point of the shell of the liquid replenishing tank (3) to the ground is h2, and the height from the lowest point of the air supply tank (4) to the ground is h3, so that h5 > h2 > h3 is satisfied.

7. The air supply system for the air suspension bearing, as recited in claim 1, characterized in that the refrigerant circulation loop comprises a flash evaporator (9), the liquid taking port is arranged in a liquid area of the flash evaporator (9), and the installation heights of the liquid replenishing tank (3) and the air supply tank (4) are lower than that of the flash evaporator (9).

8. The air supply system for the air suspension bearing as claimed in claim 7, wherein the height from the lowest point of the shell of the flash tank (9) to the ground is h6, the height from the lowest point of the shell of the liquid replenishing tank (3) to the ground is h2, and the height from the lowest point of the air supply tank (4) to the ground is h3, so that h6 > h2 > h3 is satisfied.

9. An air supply system for an air suspension bearing according to any of claims 1-8, characterized in that the volume of the make-up tank (3) is V1 and the volume of the air supply tank (4) is V2, satisfying V1 < V2.

10. Gas supply system for an aerostatic bearing according to any one of claims 1 to 8, characterized in that the gas supply tank (4) is provided with a heating device (10), the heating device (10) being switched on or off depending on the liquid level, the pressure in the gas supply tank (4).

11. Air supply system for an air suspension bearing according to claim 10, characterized in that the air supply tank (4) is further provided with a liquid level sensor (11), a pressure sensor (12).

12. An air suspension bearing air supply system according to any of claims 1-8, characterized in that the first air supply circuit (2) comprises a first passage (13), a second passage (14), a third passage (15), the first passage (13) being arranged between the liquid intake and the liquid feed tank (3), the second passage (14) being arranged between the liquid feed tank (3) and the air supply tank (4), the third passage (15) being arranged between the air supply tank (4) and the air suspension compressor (1).

13. Air supply system for an air bearing according to claim 12, characterized in that the first channel (13) is provided with a fourth regulating valve (16), the second channel (14) is provided with a third regulating valve (17) and the third channel (15) is provided with a fifth regulating valve (18).

14. The air supply system for the air suspension bearing as claimed in claim 13, wherein the refrigerant circulation loop is further provided with an adjusting return air port, the first air supply loop (2) is further provided with a first bypass (20) and a second bypass (21), the first bypass (20) is arranged between the air supply tank (3) and the adjusting return air port, and the second bypass (21) is arranged between the air supply tank (4) and the air supply tank (3).

15. Air supply system for an air bearing according to claim 14, characterized in that the first bypass (20) is provided with a first regulating valve (22) and the second bypass (21) is provided with a second regulating valve (23).

16. A method of supplying gas using the gas supply system for an air bearing of any of claims 1-15, comprising:

when the gas suspension compressor (1) is in a starting stage and a shutdown stage, or the pressure difference value between the condensing pressure and the evaporating pressure in the refrigerant circulating system is smaller than a preset value, liquid refrigerant enters the liquid supplementing tank (3) through the liquid taking port, and the gas supply tank (4) supplies gas to the gas suspension bearing in the gas suspension compressor (1).

17. The method as claimed in claim 16, wherein the gaseous refrigerant in the condenser (8) of the refrigerant circulation system is used to supply the gas suspension bearing when a pressure difference between a condensing pressure and an evaporating pressure in the refrigerant circulation system is greater than or equal to a predetermined value.

18. A method of supplying air to an air supply system for an air bearing as claimed in claim 16 wherein the air supply system is adapted to supply air to the air bearing when the air bearing is in a non-pressurized state

The first gas supply circuit (2) comprises a first passage (13) and a second passage (14); first bypass way (20) are equipped with first governing valve (22), second bypass way (21) are equipped with second governing valve (23), first way (13) are equipped with fourth governing valve (16), and when second way (14) were equipped with third governing valve (17):

controlling the first regulating valve (22) and the fourth regulating valve (16) to be opened, the second regulating valve (23) and the third regulating valve (17) to be closed, and enabling the liquid refrigerant to enter the liquid supplementing tank (3) through the liquid taking port;

when the liquid level of the liquid refrigerant in the air supply tank (4) is less than H1, liquid supplementing is carried out, the first regulating valve (22) and the fourth regulating valve (16) are controlled to be closed, the second regulating valve (23) and the third regulating valve (17) are controlled to be opened, and the liquid refrigerant flows into the air supply tank (4) from the liquid supplementing tank (3).

19. The air supply method for the air supply system of the air suspension bearing according to claim 18, characterized in that the first regulating valve (22) and the fourth regulating valve (16) are controlled to be opened, and the second regulating valve (23) and the third regulating valve (17) are controlled to be closed after a preset time when the fluid replacement is performed.

20. Method for supplying air to an air suspension bearing system according to claim 16, characterized in that when the air supply tank (4) is provided with heating means (10),

when the liquid level of the liquid refrigerant in the air supply tank (4) is more than or equal to H0, the heating device (10) is started, otherwise, the heating device (10) is closed;

and/or, when the pressure in the air supply tank (4) is less than P1, the heating device (10) is opened; when the pressure in the air supply tank (4) is not less than P1 and not more than P2, the heating device (10) keeps the current state; when the pressure in the air supply tank (4) is more than P2, the heating device (10) is closed.

21. A centrifugal chiller according to any of claims 1 to 15 or 16 to 20.

Technical Field

The invention belongs to the technical field of centrifugal water chilling units, and particularly relates to an air supply system and an air supply method for an air suspension bearing and a centrifugal water chilling unit.

Background

Centrifugal water chilling units are generally used in various building air conditioners, compressor bearings of the centrifugal water chilling units mainly adopt oil lubrication bearings, electromagnetic bearings and air suspension bearings, the oil lubrication bearings are adopted, an oil supply system needs to be added, lubricating oil can leak into a refrigerant to cause refrigerant pollution, and energy loss can be caused due to friction between the lubricating oil and a rotor; in the centrifugal compressor adopting the electromagnetic bearing, a whole set of control system of the bearing is complex, the shock resistance energy of the system is poor, and in addition, additional power-off protection means such as a protection bearing and the like are required to be added.

The gas suspension bearing is a technology for supporting a rotor by utilizing pressure generated by gas between the bearing and the rotor, is an oilless bearing, has small friction resistance between the gas and the rotor, does not need a complex control system, and has a simple structure. However, the bearing needs a gas supply system to provide gas for the operation of the bearing, and whether the design of the gas supply system is reasonable or not directly affects the working performance of the centrifugal compressor. In the air supply system in the prior art, a refrigerant pump is adopted to extract liquid refrigerant from a condenser and supply the liquid refrigerant to an air storage tank, an electric heater is installed on the air storage tank, and the electric heater heats and boosts the refrigerant and supplies air to a bearing. By adopting the refrigerant pump scheme, when the liquid level of the air supply tank is controlled, the liquid level is low, the pump is started and closed, the refrigerant pump needs to be started and stopped frequently, the reliability of the refrigerant pump can be reduced, and the reliability of an air supply system is reduced. Meanwhile, the pump consumes a part of electric energy, so that the energy efficiency of the unit is reduced, the cost of the pump is high, and the cost of the unit is increased.

Disclosure of Invention

Therefore, the invention aims to solve the technical problems that the air supply system of the air suspension bearing is unreasonable in design, the refrigerant pump is frequently started and stopped, and the reliability is low, so that the air supply system of the air suspension bearing, the air supply method and the centrifugal water chilling unit are provided.

In order to solve the above problems, the present invention provides an air supply system for an air bearing, comprising:

the air suspension compressor and a refrigerant circulation loop in which the air suspension compressor is arranged;

a liquid inlet of the first gas supply loop is connected to a liquid taking port of the refrigerant circulation loop and takes liquid from the liquid taking port, and a gas outlet of the first gas supply loop is connected to the gas suspension compressor;

the first air supply loop comprises a liquid replenishing tank and an air supply tank, the installation height of the liquid replenishing tank and the installation height of the air supply tank are lower than that of the liquid taking port, and the refrigerant in the refrigerant circulation loop can flow into the first air supply loop from the liquid taking port under the action of gravity.

Preferably, the air supply system further comprises a second air supply circuit, the second air supply circuit is arranged between the condenser of the refrigerant circulation circuit and the air supply tank in the first air supply circuit, and the second air supply circuit is provided with a check valve from the condenser to the air supply tank.

Preferably, the refrigerant circulation loop comprises an evaporator, the liquid taking port is arranged in a liquid area of the evaporator, and the installation height of the liquid replenishing tank and the air supply tank is lower than that of the evaporator.

Preferably, the height from the lowest point of the evaporator shell to the ground is h1, the height from the lowest point of the liquid replenishing tank 3 shell to the ground is h2, and the height from the lowest point of the air supply tank 4 to the ground is h3, so that h1 & gt h2 & gt h3 are satisfied.

Preferably, the refrigerant circulation loop comprises a condenser, the liquid taking port is arranged in a liquid area of the condenser, and the installation height of the liquid replenishing tank and the air supply tank is lower than that of the condenser.

Preferably, the height from the lowest point of the condenser shell to the ground is h5, the height from the lowest point of the liquid supplementing tank 3 shell to the ground is h2, and the height from the lowest point of the air supply tank 4 to the ground is h3, so that h5 & gt h2 & gt h3 are satisfied.

Preferably, the refrigerant circulation loop comprises a flash evaporator, the liquid taking port is arranged in a liquid area of the flash evaporator, and the installation height of the liquid replenishing tank and the air supply tank is lower than that of the flash evaporator.

Preferably, the height from the lowest point of the flash tank shell to the ground is h6, the height from the highest point of the liquid supplementing tank shell to the ground is h2, the height from the lowest point of the liquid supplementing tank 3 shell to the ground is h2, and the height from the lowest point of the air supply tank 4 to the ground is h3, so that h6 is more than h2 and more than h3 are met.

Preferably, the volume of the liquid replenishing tank is V1, the volume of the gas supply tank is V2, and V1 < V2 is satisfied.

Preferably, the gas supply tank is provided with a heating device which is turned on or off according to the liquid level and pressure in the gas supply tank.

Preferably, the air supply tank is also provided with a liquid level sensor and a pressure sensor.

Preferably, the first air supply circuit comprises a first passage, a second passage and a third passage, wherein the first passage is arranged between the liquid taking port and the liquid supplementing tank, the second passage is arranged between the liquid supplementing tank and the air supply tank, and the third passage is arranged between the air supply tank and the air suspension compressor.

Preferably, the first passage is provided with a fourth regulating valve, the second passage is provided with a third regulating valve, and the third passage is provided with a fifth regulating valve.

Preferably, the refrigerant circulation circuit is further provided with an adjusting return air port, the first air supply circuit is further provided with a first bypass and a second bypass, the first bypass is arranged between the liquid supplementing tank and the adjusting return air port, and the second bypass is arranged between the air supply tank and the liquid supplementing tank.

Preferably, the first bypass passage is provided with a first regulating valve, and the second bypass passage is provided with a second regulating valve.

A gas supply method using a gas suspension bearing gas supply system, comprising:

when the air suspension compressor is in a starting stage and a shutdown stage, or the pressure difference value between the condensing pressure and the evaporating pressure in the refrigerant circulating system is smaller than a preset value, liquid refrigerant enters the liquid supplementing tank through the liquid taking port, and the air supply tank supplies air to the air suspension bearing in the air suspension compressor.

The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.

Preferably, when the pressure difference between the condensing pressure and the evaporating pressure in the refrigerant circulating system is greater than or equal to a preset value, the gaseous refrigerant in the condenser of the refrigerant circulating system is adopted to supply air to the air suspension bearing.

Preferably, when the first air supply circuit comprises a first passage and a second passage; the first bypass passage is provided with a first regulating valve, the second bypass passage is provided with a second regulating valve, the first passage is provided with a fourth regulating valve, when the second passage is provided with a third regulating valve,

controlling the first regulating valve and the fourth regulating valve to be opened, closing the second regulating valve and the third regulating valve, and enabling the liquid refrigerant to enter the liquid supplementing tank through the liquid taking port;

when the liquid level of the liquid refrigerant in the gas supply tank is less than H1, liquid supplementing is carried out, the first regulating valve and the fourth regulating valve are controlled to be closed, the second regulating valve and the third regulating valve are controlled to be opened, and the liquid refrigerant flows into the gas supply tank from the liquid supplementing tank.

Preferably, when fluid infusion is performed, after the preset time, the first regulating valve and the fourth regulating valve are controlled to be opened, and the second regulating valve and the third regulating valve are controlled to be closed.

Preferably, when the gas supply tank is provided with the heating device,

when the liquid level of the liquid refrigerant in the gas supply tank is more than or equal to H0, the heating device is started, otherwise, the heating device is closed;

and/or, when the pressure in the gas supply tank is less than P1, the heating device is started; when the pressure in the air supply tank is not less than P1 and not more than P2, the heating device keeps the current state; when the pressure in the air supply tank is more than P2, the heating device is closed.

The centrifugal water chilling unit adopts the air supply system of the air suspension bearing or the air supply method.

The air supply system, the air supply method and the centrifugal water chilling unit for the air suspension bearing provided by the invention have the following beneficial effects:

the air supply system for the air suspension bearing is suitable for a centrifugal water chilling unit adopting the air suspension bearing, and solves the problems that in the prior art, the air supply system for the air suspension bearing adopts a refrigerant pump to pump liquid refrigerant from a condenser, the refrigerant pump needs to be frequently started and stopped, the reliability of the refrigerant pump is reduced, the reliability of the air supply system is reduced, meanwhile, the energy consumption of the refrigerant pump is large, and the overall energy consumption of the unit is increased. Through the mounting height difference that will get liquid mouth, fluid infusion jar, air feed jar, with the help of gravity and linker principle, realize the gas suspension bearing continuous stable air feed, guarantee the reliable steady operation of unit.

Drawings

FIG. 1 is a schematic structural diagram of an air supply system for an air bearing according to a first embodiment of the present invention;

FIG. 2 is a schematic view showing the installation of the evaporator, the fluid replenishing tank and the gas supply tank in the first embodiment;

FIG. 3 is a schematic structural diagram of an air supply system for an air bearing according to a first embodiment of the present invention;

fig. 4 is a schematic structural diagram of an air supply system for an air bearing according to a first embodiment of the present invention.

The reference numerals are represented as:

1. a gas suspension compressor; 2. a first gas supply loop; 3. a liquid replenishing tank; 4. an air supply tank; 5. a second gas supply loop; 6. a one-way valve; 7. an evaporator; 8. a condenser; 9. a flash tank; 10. a heating device; 11. a liquid level sensor; 12. a pressure sensor; 13. a first path; 14. a second path; 15. a third path; 16. a fourth regulating valve; 17. a third regulating valve; 18. a fifth regulating valve; 19. a filtration device; 20. a first bypass; 21. a second bypass path; 22. a first regulating valve; 23. a second regulating valve; 24. a throttle valve.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 4, the present application provides an air supply system for an air bearing, including: the air suspension compressor 1 and a refrigerant circulation loop in which the air suspension compressor is arranged; a liquid inlet of the first gas supply loop 2 is connected to a liquid taking port of the refrigerant circulation loop and takes liquid from the liquid taking port, and a gas outlet of the first gas supply loop 2 is connected to the gas suspension compressor 1; the first air supply loop 2 comprises a liquid replenishing tank 3 and an air supply tank 4, the installation height of the liquid replenishing tank 3 and the air supply tank 4 is lower than that of the liquid taking port, and the refrigerant in the refrigerant circulation loop can flow into the first air supply loop 2 from the liquid taking port under the action of gravity.

The utility model provides an air suspension bearing air feed system is applicable to the centrifugal chiller that adopts the air suspension bearing, has solved prior art's air suspension bearing air feed system and has adopted the refrigerant pump to extract liquid refrigerant from the condenser, and the refrigerant pump needs frequent opening and stopping, leads to the reliability of refrigerant pump to reduce, leads to air feed system's reliability to reduce, and the refrigerant pump power consumption is great simultaneously, has increased the whole power consumption of unit. Through the mounting height difference that will get liquid mouth, fluid infusion jar, air feed jar, with the help of gravity and linker principle, realize the gas suspension bearing continuous stable air feed, guarantee the reliable steady operation of unit.

Preferably, the air supply system further includes a second air supply circuit 5, the second air supply circuit 5 is disposed between a condenser 8 of the refrigerant circulation circuit and the air supply tank 4 of the first air supply circuit 2, and a check valve 6 is disposed on the second air supply circuit 5 from the condenser 8 to the air supply tank 4.

Second air feed return circuit 5 in this application is used for being normal in the cooling water set operation, condenser pressure and the sufficient big of evaporimeter pressure differential in the unit, gaseous refrigerant just can satisfy the air feed demand of gas suspension bearing in the condenser this moment, consequently, through second air feed return circuit 5 with condenser 8 and the one-way intercommunication of air feed tank 4, it is enough big to realize the unit condensation evaporation pressure differential, when the condenser can satisfy the bearing air feed, the air feed that can be minimum at first.

As shown in fig. 1 and 2, in the first embodiment of the present application, the refrigerant circulation loop includes an evaporator 7, the liquid taking port is disposed in a liquid region of the evaporator 7, and the installation heights of the liquid replenishing tank 3 and the gas supply tank 4 are lower than that of the evaporator 7.

In refrigerating system, the refrigerant exists with gaseous state and two kinds of liquid forms simultaneously in evaporimeter or heat exchanger, again because the action of gravity, gaseous state is last, and liquid is under, forms obvious gaseous state district and liquid district in inside, gets the liquid mouth and sets up the liquid district at evaporimeter 7 in this application to the effect of liquid refrigerant is drawed in the realization.

The air supply system of this embodiment one, first air feed return circuit 2 gets liquid through evaporimeter 7, and the liquid level is higher in evaporimeter 7 in refrigerant circulation system, can not influence the normal performance of evaporimeter 7 after getting liquid, compares in the way of prior art extraction liquid refrigerant from the condenser, gets liquid reliability from evaporimeter 7 and is higher, and is minimum to the influence of unit refrigeration performance.

Preferably, in order to make the liquid refrigerant smoothly flow into the first air supply circuit 2 under the action of gravity, the height from the lowest point of the shell of the evaporator 7 to the ground is h1, the height from the lowest point of the shell of the liquid supplementing tank 3 to the ground is h2, and the height from the lowest point of the air supply tank 4 to the ground is h3, so that h1 > h2 > h3 is satisfied.

In the centrifugal water chilling unit, although the liquid refrigerant level in the evaporator 7 is the highest, because the pressure in the evaporator is the lowest relative to the pressure of the condenser 8 and the flash evaporator 9, when the first air supply loop 2 takes liquid from the evaporator 7, the phenomenon that the pressure fluctuation in the liquid supplementing tank 3 and the air supply tank 4 is large may occur, so the air supply system of the application can also take liquid from the condenser 8 and the flash evaporator 9, which respectively correspond to the schemes of the second embodiment and the third embodiment. Although the liquid level of the liquid refrigerant in the condenser 8 and the flash evaporator 9 is lower than that of the evaporator 7, the pressure fluctuation in the liquid replenishing tank 3 and the air supply tank 4 caused in the liquid replenishing process is small because the pressure is large.

As shown in fig. 3, in the second embodiment of the present application, the refrigerant circulation circuit includes a condenser 8, the liquid taking port is disposed in a liquid region of the condenser 8, and the installation heights of the liquid replenishing tank 3 and the gas supply tank 4 are lower than the condenser 8.

Preferably, in order to make the liquid refrigerant smoothly flow into the first air supply circuit 2 under the action of gravity, the height from the lowest point of the shell of the condenser 8 to the ground is h5, the height from the lowest point of the shell of the liquid supplementing tank 3 to the ground is h2, and the height from the lowest point of the air supply tank 4 to the ground is h3, so that h5 > h2 > h3 are satisfied.

As shown in fig. 4, in the third embodiment of the present application, the refrigerant circulation circuit includes a flash tank 9, the liquid taking port is disposed in a liquid region of the flash tank 9, and the installation heights of the liquid replenishing tank 3 and the gas supply tank 4 are lower than that of the flash tank 9.

Preferably, in order to make the liquid refrigerant smoothly flow into the first air supply circuit 2 under the action of gravity, the height from the lowest point of the shell of the flash tank 9 to the ground is h6, the height from the lowest point of the shell of the liquid supplementing tank 3 to the ground is h2, and the height from the lowest point of the air supply tank 4 to the ground is h3, so that h6 > h2 > h3 is satisfied.

In consideration of the fact that the liquid levels of the condenser 8 and the flash tank 9 are unstable and certain risk is generated for liquid supply, liquid level detection equipment can be additionally arranged in the condenser 8 and the flash tank 9 to detect and feed back the liquid levels in the condenser 8 and the flash tank 9 in real time, and the problem that insufficient liquid supply causes insufficient gas supply of a gas suspension bearing is solved.

In all the embodiments of the present application, the liquid refrigerant flowing out of the liquid taking port first enters the liquid replenishing tank 3, and then is replenished from the liquid replenishing tank 3 to the gas supply tank 4, so as to avoid excessive pressure fluctuation of the gas supply tank 4 during liquid replenishing, the volume of the liquid replenishing tank 3 is V1, the volume of the gas supply tank 4 is V2, and V1 < V2 is satisfied. The volume and the pressure are inversely proportional, the influence of the same amount of refrigerant on the internal pressure in the liquid supplementing tank 3 is larger than the influence generated in the gas supply tank 4, and the refrigerant is vaporized due to the temperature rise after entering the gas supply tank 4, so that the pressure is increased, and the volume of the gas supply tank 4 is large, and the pressure value can be balanced.

In all the above embodiments of the present application, it is preferable that the gas supply tank 4 is provided with a heating device 10, and the heating device 10 is turned on or off according to the liquid level, pressure in the gas supply tank 4. The lowest liquid level value of liquid refrigerant in the air supply tank 4 is H0, the liquid replenishing level value of the liquid refrigerant in the air supply tank is H1, and the target liquid level value of the liquid refrigerant in the air supply tank is H2, wherein H2 is more than H1 is more than H0. H0 is the liquid level for limiting the on-state of the electric heater, and the electric heater can be started only by ensuring that the electric heater is soaked by liquid refrigerant. H1 is the liquid level of the liquid supplement, when the liquid level drops to H1, the liquid supplement control is needed when the liquid refrigerant in the gas supply tank is less. H2 is a control for the maximum level of the gas supply tank, which cannot be higher than H2, and up the gas supply line, which is too high and may cause liquid to enter the third passage 15 and eventually the aerostatic bearing, affecting its performance.

Preferably, in order to detect the liquid level and the pressure in the gas supply tank 4, the gas supply tank 4 is further provided with a liquid level sensor 11 and a pressure sensor 12.

Preferably, the first air supply circuit 2 comprises a first passage 13, a second passage 14 and a third passage 15, the first passage 13 is arranged between the liquid taking port and the liquid replenishing tank 3, the second passage 14 is arranged between the liquid replenishing tank 3 and the air supply tank 4, and the third passage 15 is arranged between the air supply tank 4 and the air suspension compressor 1. The first passage 13 is provided with a fourth regulating valve 16, the second passage 14 is provided with a third regulating valve 17, and the third passage 15 is provided with a fifth regulating valve 18 and a filter device 19. Therefore, the first air supply loop 2 controls the on-off of the first channel 13 through the fourth regulating valve 16, namely controls the on-off of the liquid refrigerant conveyed from the liquid taking port to the liquid supplementing tank 3, controls the on-off of the second channel 14 through the third regulating valve 17, namely controls the on-off of the liquid supplementing tank 3 to the air supply tank 4, and controls the on-off of the third channel 15 through the fifth regulating valve 18, namely controls the on-off of the air supply from the air supply tank 4 to the air suspension bearing.

Preferably, in order to ensure the normal fluid supply of the fluid supplement tank 3 and the fluid supply tank 4, the refrigerant circulation circuit is further provided with an adjusting return port, the first fluid supply circuit 2 is further provided with a first bypass passage 20 and a second bypass passage 21, the first bypass passage 20 is arranged between the fluid supplement tank 3 and the adjusting return port, the second bypass passage 21 is arranged between the fluid supply tank 4 and the fluid supplement tank 3, the first bypass passage 20 is provided with a first regulating valve 22, and the second bypass passage 21 is provided with a second regulating valve 23. When the liquid taking port conveys the liquid refrigerant to the liquid supplementing tank 3, the first regulating valve 22 is opened, and the first bypass passage 20 is communicated, so that the liquid refrigerant smoothly flows into the liquid supplementing tank 3. When the liquid supply tank 3 supplies liquid to the gas supply tank 4, the second regulating valve 23 is opened, and the second bypass passage 21 is opened, so that the liquid refrigerant smoothly flows into the gas supply tank 4.

Preferably, the position of the return air opening is adjusted to correspond to the position of the liquid extraction opening, in the first embodiment the liquid extraction opening is located in the liquid region of the evaporator 7, and the return air opening is then adjusted to be located in the gaseous region of the evaporator 7, and correspondingly in the second embodiment the return air opening is adjusted to be located in the gaseous region of the condenser 8, and in the third embodiment the return air opening is adjusted to be located in the gaseous region of the flash tank 9.

The application provides a gas suspension bearing air feed system, according to the unit actual design condition, fluid infusion jar 3 can follow the part of difference and get liquid, and it is better to use the suitability, arranges fluid infusion jar, air feed jar and unit evaporimeter, condenser, flash tank in the height of difference, through orderly, nimble regulation of each valve, utilizes gravity and linker principle, realizes the gas supply to gas suspension bearing continuous stability, guarantees the reliable steady operation of unit.

In the operation process of the centrifugal water chilling unit, the centrifugal water chilling unit can be divided into four different states, namely a starting process state, a stopping process state, a small pressure difference between condenser pressure and an evaporator (condensing pressure minus evaporating pressure), and a large enough pressure difference between the condenser pressure and the evaporator (condensing pressure minus evaporating pressure).

In the state I, the output of the compressor is insufficient, the pressure difference cannot be formed inside the refrigerant circulating system, and the air suspension bearing needs to be supplied with air by an external system when the air suspension bearing normally operates. In the second state, after the motor of the unit is stopped, the gas suspension bearing can still idle for a period of time due to inertia, and the gas supply system needs to supply gas continuously until the bearing stops running. In the third state, although pressure difference is formed, the pressure difference is small, and the generated air supply pressure is not enough to meet the normal requirement of the air suspension bearing. In the state IV, enough pressure difference is formed in the refrigerant circulating system, and the gas suspension bearing can normally operate only by the pressure of the gaseous refrigerant in the condenser. Therefore, when the unit is in the state (c), external air supply needs to be performed by the first air supply circuit 2, and when the unit is in the state (c), air supply can be completed only by the unit itself, thereby reducing the energy consumed for maintaining the air supply system.

The application also provides an air supply method adopting the air supply system of the air suspension bearing, which comprises the following steps:

in the first working mode, when the air suspension compressor 1 is in a starting stage and a shutdown stage, or the pressure difference value between the condensing pressure and the evaporating pressure in the refrigerant circulating system is smaller than a preset value, corresponding to the first state and the second state, liquid refrigerant enters the liquid replenishing tank 3 through the liquid taking port, and the air supply tank 4 supplies air to the air suspension bearing in the air suspension compressor 1.

Preferably, when the first air supply circuit 2 comprises a first passage 13, a second passage 14; the first bypass passage 20 is provided with a first regulating valve 22, the second bypass passage 21 is provided with a second regulating valve 23, the first passage 13 is provided with a fourth regulating valve 16, when the second passage 14 is provided with a third regulating valve 17, the first regulating valve 22 and the fourth regulating valve 16 are controlled to be opened, the second regulating valve 23 and the third regulating valve 17 are controlled to be closed, and liquid refrigerant enters the liquid supplementing tank 3 through the liquid taking port;

the liquid level of the liquid refrigerant is continuously reduced along with the consumption of the liquid refrigerant in the air supply tank, when the liquid level of the liquid refrigerant in the air supply tank 4 is less than H1, liquid supplementing is carried out, the first regulating valve 22 and the fourth regulating valve 16 are controlled to be closed, the second regulating valve 23 and the third regulating valve 17 are controlled to be opened, the liquid refrigerant in the liquid supplementing tank 3 flows into the air supply tank 4 by utilizing the gravity and the communicating device principle, and the liquid refrigerant in the air supply tank 4 is supplemented.

When the liquid supplementing is carried out, the liquid supplementing time can be set to be 10 seconds through a preset time period, the first regulating valve 22 and the fourth regulating valve 16 are controlled to be opened, the second regulating valve 23 and the third regulating valve 17 are closed, after the liquid supplementing time lasts for 10 seconds, the first regulating valve 22 and the fourth regulating valve 16 are controlled to be closed, the second regulating valve 23 and the third regulating valve 17 are controlled to be opened, the liquid refrigerant at the liquid taking port can flow to the liquid supplementing tank 3, the liquid refrigerant in the liquid supplementing tank 3 can be filled again, so that the liquid supplementing is carried out on the gas supply tank 4 next time, and a complete closed-loop liquid supplementing circulation is formed.

In the second working mode, when the pressure difference value between the condensing pressure and the evaporating pressure in the refrigerant circulating system is greater than or equal to the preset value, namely corresponding to the state (r), the gaseous refrigerant in the condenser 8 in the refrigerant circulating system is adopted to supply air to the air suspension bearing.

Preferably, the first regulating valve 22 and the fourth regulating valve 16 are controlled to be opened, the second regulating valve 23 and the third regulating valve 17 are controlled to be closed, the heating device 10 is closed, and the fifth regulating valve 18 is controlled to regulate the opening degree of the valve according to the air supply demand of the compressor bearing.

When the heating device 10 is arranged in the gas supply tank 4, when the liquid level of the liquid refrigerant in the gas supply tank 4 is more than or equal to H0, the heating device 10 is started, otherwise, the heating device 10 is closed;

and/or, when the pressure in the gas supply tank 4 is less than P1, the heating device 10 is opened; when the pressure in the air supply tank 4 is not less than P1 and not more than P2, the heating device 10 keeps the current state; when the pressure in the gas supply tank 4 is greater than P2, the heating device 10 is turned off.

In order to avoid frequent opening and closing of the heating device 10, it is assumed that the pressure in the air supply tank 4 is gradually increased from a pressure point lower than the pressure point P1, and when the pressure reaches the pressure point P1, the heating device 10 is turned on, and when the pressure continues to be increased to the pressure point P2, the heating device is turned off. Then, as the supply air is consumed, the pressure in the supply air tank 4 gradually decreases from a pressure point higher than P2 to a pressure point P2, the heating device 10 is not immediately turned on, but the heating device 10 is turned on again as the pressure further decreases to a pressure point P1. Therefore, the time interval of the pressure reduction from P2 to P1 is ensured between the actions of the heating device 10, the heating device 10 is not frequently opened and closed, the service life of the heating device 10 is ensured, and energy can be saved.

The centrifugal water chilling unit adopts the air supply system of the air suspension bearing or the air supply method.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.