An air conditioning system, air conditioner and control method

Abstract

The application provides an air conditioning system, an air conditioner and a control method, and belongs to the technical field of air conditioning. The air conditioning system comprises a compression device, a condenser, a throttling device and an evaporator which are sequentially connected in series to form a refrigerant circulation loop. The air conditioning system further comprises a bypass mechanism. The bypass mechanism forms a bypass flow path between the condenser and the evaporator. The bypass mechanism is used to selectively drive liquid refrigerant in the evaporator to flow to the condenser through the bypass flow path, so that the bypass mechanism is in a first state. Alternatively, the bypass mechanism is used to drive liquid refrigerant in the condenser to flow to the evaporator through the bypass flow path, so that the bypass mechanism is in a second state. According to the application, the limitation that the traditional air conditioning system only relies on pressure difference and gravity to realize passive distribution of refrigerant is broken, active stable control of the liquid level of the evaporator, the flash device and the condenser can be realized, and the operation reliability and safety of the unit are greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of air conditioning technology, specifically relating to an air conditioning system, an air conditioner, and a control method. Background Technology

[0002] Centrifugal chillers are the main equipment in air conditioning systems of large public buildings and industrial facilities. Their energy efficiency and reliability directly affect the building's operating costs and environmental impact. Among the core components of the compressor, innovation in bearing technology is key to improving unit performance. Currently, mainstream bearing types include oil-lubricated bearings (relying on complex oil supply, return, and cooling systems, posing leakage risks and high maintenance costs), magnetic levitation bearings (achieving contactless operation through electromagnetic force, offering high efficiency but requiring sophisticated electrical control systems and power failure protection, resulting in a bulky structure), and the rapidly developing air-suspended bearings—an innovative technology based on gas dynamics principles.

[0003] Air-bearing systems utilize compressed air or refrigerant gas to form a stable air film between the shaft and the bearing, achieving frictionless support. Their core advantages are significant: Firstly, they completely eliminate the need for oil lubrication systems, removing oil leakage pollution, environmental risks, and the need for regular maintenance. Simultaneously, because the bearing is in a suspended state, mechanical friction losses approach zero, increasing the unit's coefficient of performance (COP) by 5%-10% and significantly reducing operating energy consumption. Secondly, compared to magnetic bearings, they eliminate the need for external electric drive for electromagnets, greatly simplifying the control system, reducing potential failure points and hardware costs. Furthermore, the bearings are more compact, better suited to the modern trend of miniaturization and lightweight design in generating units.

[0004] However, the intricate structure of air-bearing systems also presents unique risks. Their air film relies on a pure gas environment; if liquid refrigerant gets mixed into the compressor's suction or makeup air inlet (due to uncontrolled evaporator levels or system fluctuations), the droplets will instantly disrupt the integrity of the air film, causing direct metal-to-metal contact between the shaft and the bearing housing, leading to severe wear and even permanent damage. This not only results in costly downtime repairs but may also affect the entire unit.

[0005] During actual operation, air conditioning systems are affected by multiple factors, including fluctuations in water temperature, dynamic adjustments to unit load, and limited adjustable opening range of the expansion valve. This causes continuous and random fluctuations in the refrigerant level inside the evaporator, resulting in poor level stability. When the refrigerant level inside the evaporator is too high, liquid refrigerant easily enters the compressor with the suction air, causing the compressor to operate with liquid, leading to liquid slugging, unit surge, and other malfunctions, severely damaging the compressor. When the refrigerant level inside the evaporator is too low, the effective heat exchange refrigerant volume within the evaporator is insufficient, resulting in low refrigerant flow on the compressor suction side. This easily triggers the system's low-pressure protection, causing abnormal unit shutdown and affecting the reliability of continuous operation. Existing conventional air conditioning systems rely solely on the pressure difference between the condenser and evaporator to drive the refrigerant circulation; after the unit stops, the refrigerant relies solely on its own gravity to achieve natural distribution equilibrium, leaving the refrigerant level inside the evaporator in a completely passive distribution state. When the evaporator is working, it cannot actively replenish or drain refrigerant to address the two extreme conditions of excessively high or low refrigerant levels, making it difficult to maintain the refrigerant level in the evaporator within a reasonable range, resulting in poor unit operation stability. Summary of the Invention

[0006] Therefore, the present invention provides an air conditioning system, an air conditioner, and a control method to solve the technical defect of existing air conditioning systems that the evaporator cannot actively replenish or drain refrigerant under two extreme conditions: excessively high refrigerant level and excessively low refrigerant level.

[0007] To address the aforementioned problems, the present invention provides an air conditioning system comprising a compressor, a condenser, a throttling device, and an evaporator connected end-to-end to form a refrigerant circulation loop; wherein the air conditioning system further comprises a bypass mechanism, which forms a bypass flow path between the condenser and the evaporator, and is used to selectively drive liquid refrigerant in the evaporator to flow through the bypass flow path to the condenser, thereby placing the bypass mechanism in a first state; or to drive liquid refrigerant in the condenser to flow through the bypass flow path to the evaporator, thereby placing the bypass mechanism in a second state.

[0008] In some embodiments, the bypass mechanism includes a pump body and a bypass reversing channel. The bypass mechanism connects the condenser and the evaporator through the bypass reversing channel to form the bypass flow path between the condenser and the evaporator. The pump body is disposed in the bypass reversing channel. The bypass reversing channel is used to control the flow direction of the internal refrigerant, so that in the first state, the inlet of the pump body is connected to the evaporator and the outlet of the pump body is connected to the condenser, so that the bypass mechanism can drive the liquid refrigerant in the evaporator to flow to the condenser through the bypass flow path via the pump body; and in the second state, the inlet of the pump body is connected to the condenser and the outlet of the pump body is connected to the evaporator, so that the bypass mechanism can drive the liquid refrigerant in the condenser to flow to the evaporator through the bypass flow path via the pump body.

[0009] In some embodiments, the bypass reversing flow channel includes a first flow channel, a second flow channel, a third flow channel, and a fourth flow channel; the inlet of the pump body is connected to the evaporator through the first flow channel and to the condenser through the second flow channel; the outlet of the pump body is connected to the evaporator through the third flow channel and to the condenser through the fourth flow channel; wherein each of the first, second, third, and fourth flow channels can be opened or closed.

[0010] In some embodiments, a first control valve is provided on the first flow channel, and the first flow channel is opened or closed by the first control valve;

[0011] And / or, the second flow channel is provided with a second control valve, and the second flow channel is opened or closed by the second control valve;

[0012] And / or, the third flow channel is provided with a third control valve, and the third flow channel is opened or closed by the third control valve;

[0013] And / or, the fourth flow channel is provided with a fourth control valve, and the fourth flow channel is opened or closed by the fourth control valve.

[0014] In some implementations, in the first state, both the first and fourth flow channels are open, and both the second and third flow channels are closed; in the second state, both the first and fourth flow channels are closed, and both the second and third flow channels are open.

[0015] In some embodiments, the fourth flow channel is provided with a one-way flow mechanism, which is used to prevent the refrigerant in the condenser from flowing back to the pump body through the fourth flow channel.

[0016] In some embodiments, the bypass mechanism further includes a filter, and both the first flow channel and the second flow channel are connected to the inlet of the pump body through the filter.

[0017] In some embodiments, the refrigerant circulation loop is further connected in series between the condenser and the evaporator, the compression device has a gas inlet, and the gas outlet of the flash evaporator and the gas inlet of the compression device can be connected or disconnected.

[0018] In some embodiments, the throttling device includes a first throttling valve disposed between the condenser and the flash evaporator, the first throttling valve being used to regulate the refrigerant flow rate from the condenser into the flash evaporator.

[0019] In some embodiments, the present invention also provides an air conditioner comprising the air conditioning system described in any one of the above embodiments.

[0020] In some embodiments, the present invention also provides a control method for an air conditioning system according to any one of the above claims, comprising the following steps:

[0021] When the refrigerant level in the evaporator is higher than the preset upper limit level, the bypass mechanism is controlled to drive the liquid refrigerant in the evaporator to flow to the condenser through the bypass flow path until the refrigerant level in the evaporator drops to the preset level range.

[0022] And / or, when the refrigerant level in the evaporator is lower than the preset lower limit level, the bypass mechanism is controlled to drive the liquid refrigerant in the condenser to flow through the bypass flow path to the evaporator until the refrigerant level in the evaporator rises back to the preset level range.

[0023] In some embodiments, when the refrigerant circulation loop is further connected in series between the condenser and the evaporator, and the compression device has a gas inlet, and the gas outlet of the flash device and the gas inlet of the compression device can be connected or disconnected, if the refrigerant level of the flash device is greater than or equal to a preset alarm level, the connection between the gas outlet of the flash device and the gas inlet of the compression device is cut off; otherwise, the connection between the gas outlet of the flash device and the gas inlet of the compression device is opened.

[0024] In some embodiments, when the throttling device includes a first throttling valve disposed between the condenser and the flash evaporator, and the first throttling valve is used to regulate the refrigerant flow rate from the condenser into the flash evaporator, if the refrigerant level in the flash evaporator is higher than the target level, the opening of the first throttling valve is reduced; otherwise, the opening of the first throttling valve is increased; wherein the preset alarm level is greater than the target level.

[0025] The air conditioning system, air conditioner, and control method provided by this invention have the following beneficial effects:

[0026] 1. The present invention, through the bypass mechanism, can selectively drive the liquid refrigerant in the evaporator to flow to the condenser through the bypass flow path, or drive the liquid refrigerant in the condenser to flow to the evaporator through the bypass flow path, thus breaking the limitation of traditional air conditioning systems that rely solely on pressure difference and gravity to achieve passive refrigerant distribution. When the refrigerant level is too high during evaporator operation, the bypass mechanism can be controlled to drive the liquid refrigerant in the evaporator to the condenser through the bypass flow path, achieving active liquid drainage and completely solving the problems of liquid carryover and liquid slugging in the compressor suction, effectively protecting the core components of the compressor. When the refrigerant level is too low during evaporator operation, the bypass mechanism can be controlled to drive the liquid refrigerant in the condenser to the evaporator through the bypass flow path, achieving active liquid replenishment, ensuring stable evaporator heat exchange efficiency and compressor suction flow, and preventing abnormal shutdown due to low pressure protection. This overcomes the technical defects of existing air conditioning systems that cannot actively replenish or drain refrigerant under extreme conditions of excessively high or low refrigerant levels. This invention can adapt to complex actual conditions such as unit load fluctuations, water temperature changes, and limited throttle valve opening, significantly improving the stability and reliability of the air conditioning unit under all operating conditions and extending the unit's service life.

[0027] 2. This invention improves the operational reliability of air conditioning units by controlling the refrigerant levels in the evaporator and condenser to appropriate positions, thus avoiding problems such as surge, high-pressure maintenance, low-pressure protection, cooling failure, and liquid carryover caused by excessively high or low liquid levels. This invention also prevents damage to the air suspension bearings of the air suspension compressor due to liquid carryover during intake or replenishment, thereby improving the operational reliability of air conditioning units and avoiding significant economic losses. Attached Figure Description

[0028] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0029] Figure 1 This is a flow diagram of the air conditioning system of the present invention.

[0030] The attached figures are labeled as follows:

[0031] 1. Compression unit; 2. Check valve; 3. Condenser; 4. Flash evaporator; 5. Throttling device; 6. Evaporator; 7. Pump body; 8. First flow channel; 9. Second flow channel; 10. Third flow channel; 11. Fourth flow channel; 12. One-way flow mechanism; 13. Filter; 14. Gas supply control valve; 15. First level gauge; 16. Second level gauge; 41. Gas outlet of flash evaporator; 51. First throttle valve; 52. Second throttle valve; 71. Pump body inlet; 72. Pump body outlet; 81. First control valve; 91. Second control valve; 101. Third control valve; 111. Fourth control valve; 100. Bypass mechanism; 1a. Gas supply port; 10a. Bypass flow path; 10a1. Bypass reversing flow path. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0034] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0035] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0036] like Figure 1 As shown, according to an embodiment of the present invention, an air conditioning system is provided, comprising a compressor 1, a condenser 3, a throttling device 5, and an evaporator 6 connected end-to-end to form a refrigerant circulation loop. The air conditioning system further includes a bypass mechanism 100, which forms a bypass flow path 10a between the condenser 3 and the evaporator 6. The bypass mechanism 100 is used to selectively drive liquid refrigerant in the evaporator 6 to flow through the bypass flow path 10a to the condenser 3, thereby placing the bypass mechanism 100 in a first state; or to drive liquid refrigerant in the condenser 3 to flow through the bypass flow path 10a to the evaporator 6, thereby placing the bypass mechanism 100 in a second state.

[0037] In the above example, the present invention, through the bypass mechanism 100, can selectively drive the liquid refrigerant in the evaporator 6 to flow to the condenser 3 through the bypass flow path 10a, or drive the liquid refrigerant in the condenser 3 to flow to the evaporator 6 through the bypass flow path 10a, thus breaking the limitation of the traditional air conditioning system that relies solely on pressure difference and gravity to achieve passive distribution of refrigerant. When the refrigerant level in the evaporator 6 is too high, the bypass mechanism 100 can be controlled to drive the liquid refrigerant in the evaporator 6 to flow to the condenser 3 through the bypass flow path 10a, achieving active liquid drainage and completely solving the problems of liquid carryover and liquid slugging in the compressor suction, effectively protecting the core components of the compressor. When the refrigerant level in the evaporator 6 is too low, the bypass mechanism 100 can be controlled to drive the liquid refrigerant in the condenser 3 to flow to the evaporator 6 through the bypass flow path 10a, achieving active liquid replenishment, ensuring the heat exchange efficiency of the evaporator 6 and the stability of the compressor suction flow, and preventing abnormal shutdown due to low pressure protection. This overcomes the technical defect in existing air conditioning systems where the evaporator 6 cannot actively replenish or drain refrigerant under extreme conditions of excessively high or low refrigerant levels. This invention can adapt to complex actual conditions such as unit load fluctuations, water temperature changes, and limited throttle valve opening, significantly improving the stability and reliability of the air conditioning unit under all operating conditions and extending the unit's service life.

[0038] To achieve the function of the aforementioned bypass mechanism 100, in some embodiments, such as Figure 1 As shown, the aforementioned bypass mechanism 100 may include a pump body 7 and a bypass reversing flow channel 10a1. The bypass mechanism 100 connects the condenser 3 and the evaporator 6 through the bypass reversing flow channel 10a1 to form the aforementioned bypass flow path 10a between the condenser 3 and the evaporator 6. The pump body 7 is disposed in the bypass reversing flow channel 10a1. The bypass reversing channel 10a1 is used to control the flow direction of the internal refrigerant. In the first state, the pump body inlet 71 is connected to the evaporator 6 and the pump body outlet 72 is connected to the condenser 3, so that the bypass mechanism 100 can drive the liquid refrigerant in the evaporator 6 to flow to the condenser 3 through the bypass channel 10a via the pump body 7. In the second state, the pump body inlet 71 is connected to the condenser 3 and the pump body outlet 72 is connected to the evaporator 6, so that the bypass mechanism 100 can drive the liquid refrigerant in the condenser 3 to flow to the evaporator 6 through the bypass channel 10a via the pump body 7.

[0039] In the above example, the bypass mechanism 100 can form the aforementioned bypass flow path 10a through the bypass reversing flow channel 10a1, and through the cooperation of the bypass reversing flow channel 10a1 and the pump body 7, the bypass mechanism 100 can switch between the first state and the second state, thereby realizing the function of the aforementioned bypass mechanism 100.

[0040] In some embodiments, the aforementioned pump body 7 can be a refrigerant pump.

[0041] To achieve the function of the aforementioned bypass reversing channel 10a1, in some embodiments, such as Figure 1 As shown, the aforementioned bypass reversing flow channel 10a1 includes a first flow channel 8, a second flow channel 9, a third flow channel 10, and a fourth flow channel 11. The pump body inlet 71 is connected to the evaporator 6 through the first flow channel 8, and the pump body inlet 71 is connected to the condenser 3 through the second flow channel 9. The pump body outlet 72 is connected to the evaporator 6 through the third flow channel 10, and the pump body outlet 72 is connected to the condenser 3 through the fourth flow channel 11. Each of the first flow channel 8, second flow channel 9, third flow channel 10, and fourth flow channel 11 can be opened or closed.

[0042] In the above example, the first flow channel 8, the second flow channel 9, the third flow channel 10, and the fourth flow channel 11 cooperate to open or close, thereby realizing the function of the aforementioned bypass reversing flow channel 10a1. Specifically, in the first state, both the first flow channel 8 and the fourth flow channel 11 are open, and both the second flow channel 9 and the third flow channel 10 are closed, so that the pump body inlet 71 is connected to the evaporator 6 through the first flow channel 8, and the pump body outlet 72 is connected to the condenser 3 through the fourth flow channel 11. At this time, when the pump body 7 starts, it can drive the liquid refrigerant in the evaporator 6 to flow to the condenser 3 through the bypass flow path 10a. In the second state, the first flow channel 8 and the fourth flow channel 11 are both closed, and the second flow channel 9 and the third flow channel 10 are both open, so that the pump body inlet 71 is connected to the condenser 3 through the second flow channel 9, and the pump body outlet 72 is connected to the evaporator 6 through the third flow channel 10. At this time, when the pump body 7 starts, it can drive the liquid refrigerant in the condenser 3 to flow to the evaporator 6 through the bypass flow path 10a.

[0043] In order to enable the aforementioned first flow channel 8 to open or close, in some embodiments, such as Figure 1 As shown, a first control valve 81 may be provided on the aforementioned first flow channel 8, and the first flow channel 8 is opened or closed by the first control valve 81. The first control valve 81 may be an electric valve.

[0044] In order to enable the aforementioned second flow channel 9 to open or close, in some embodiments, such as Figure 1 As shown, a second control valve 91 is provided on the second flow channel 9, and the second flow channel 9 is opened or closed by the second control valve 91. The second control valve 91 can be an electric valve.

[0045] In order to enable the aforementioned third flow channel 10 to open or close, in some embodiments, such as Figure 1 As shown, a third control valve 101 is provided on the third flow channel 10, and the third flow channel 10 is opened or closed by the third control valve 101. The third control valve 101 can be an electric valve.

[0046] In order to enable the aforementioned fourth flow channel 11 to open or close, in some embodiments, such as Figure 1 As shown, a fourth control valve 111 is provided on the fourth flow channel 11, and the fourth flow channel 11 is opened or closed by the fourth control valve 111. The fourth control valve 111 can be an electric valve.

[0047] In some implementations, such as Figure 1 As shown, the aforementioned fourth flow channel 11 may be equipped with a one-way flow mechanism 12. The one-way flow mechanism 12 is used to block the refrigerant in the condenser 3 from flowing back to the pump body 7 through the fourth flow channel 11, preventing refrigerant backflow from causing pipeline pressure disturbance. The one-way flow mechanism 12 can be a one-way valve.

[0048] In some implementations, such as Figure 1 As shown, the aforementioned bypass mechanism 100 also includes a filter 13, and the first flow channel 8 and the second flow channel 9 are both connected to the inlet 71 of the pump body through the filter 13.

[0049] In the above example, filtering the refrigerant flowing into the pump body 7 through filter 13 can ensure stable pump flow rate, accurate liquid level regulation response of evaporator 6, and prevent impurities from clogging the flow channel and causing liquid level regulation failure.

[0050] In some implementations, such as Figure 1 As shown, the aforementioned refrigerant circulation loop also has a flash evaporator 4 connected in series between the condenser 3 and the evaporator 6. The compression device 1 has a gas supply port 1a. The gas outlet 41 of the flash evaporator and the gas supply port 1a of the compression device can be connected or disconnected.

[0051] In the above example, by setting the flash evaporator 4 to replenish the compressor 1 with gas and increase its enthalpy, the air conditioning system's low-temperature heating and high-temperature cooling capabilities can be significantly improved, resulting in higher heat exchange efficiency and lower exhaust temperature. When the refrigerant level in the flash evaporator 4 exceeds the alarm level, the connection between the flash evaporator's outlet 41 and the compressor's gas inlet 1a can be cut off, preventing excessive liquid accumulation in the flash evaporator 4 and the liquid refrigerant from being drawn into the compressor's gas inlet 1a. This prevents liquid slugging in the gas replenishment circuit from the source and significantly extends the service life of the compressor 1.

[0052] In some embodiments, the aforementioned flashing device 4 can be a flash generator.

[0053] In some implementations, such as Figure 1 As shown, the air outlet 41 of the aforementioned flash ignition device is connected to the air supply port 1a of the compression device via an air supply control valve 14, so as to realize the connection or disconnection between the two through the air supply control valve 14. The air supply control valve 14 can be an electric valve.

[0054] In some implementations, such as Figure 1As shown, the aforementioned throttling device 5 may include a first throttling valve 51, which is disposed between the condenser 3 and the flash evaporation device 4. The first throttling valve 51 is used to regulate the flow rate of refrigerant flowing from the condenser 3 into the flash evaporation device 4.

[0055] In the above example, the first throttle valve 51 can control the refrigerant level of the flash evaporator 4 in a closed loop. When the refrigerant level of the flash evaporator 4 is too high, the first throttle valve 51 can be closed to reduce the amount of refrigerant flowing into the flash evaporator 4. When the refrigerant level of the flash evaporator 4 is too low, the first throttle valve 51 can be opened to increase the liquid supply, stabilize the gas-liquid separation conditions inside the flash evaporator 4, ensure the stability of the dryness of the gaseous refrigerant, and maintain the optimal gas replenishment effect.

[0056] In some implementations, such as Figure 1 As shown, the aforementioned throttling device 5 also includes a second throttling valve 52, which is located between the flash evaporator 4 and the evaporator 6. The second throttling valve 52 is used to throttle and reduce the pressure of the refrigerant before it enters the evaporator 6. After the refrigerant is separated into liquid phases by the flash evaporator 4, it is further throttled by the second throttling valve 52, precisely reducing the pressure to the required evaporation pressure of the evaporator 6, ensuring stable evaporation and heat exchange inside the evaporator 6, and resulting in higher refrigeration and heat exchange efficiency. Furthermore, the second throttling valve 52 and the first throttling valve 51 form a two-stage throttling structure, allowing independent control of the refrigerant level in the flash evaporator 4 and the evaporation pressure in the evaporator 6. The two stages of regulation do not interfere with each other, providing greater control flexibility.

[0057] In some embodiments, the aforementioned first throttle valve 51 and second throttle valve 52 can both be electronic expansion valves.

[0058] In some implementations, such as Figure 1 As shown, the aforementioned air conditioning system includes a first level gauge 15, which is used to detect the refrigerant level of the evaporator 6 in order to monitor the refrigerant level of the evaporator 6 in real time and facilitate real-time control of the refrigerant level of the evaporator 6.

[0059] In some implementations, such as Figure 1 As shown, the aforementioned air conditioning system includes a second level gauge 16, which is used to detect the refrigerant level of the flash evaporation device 4, so as to monitor the refrigerant level of the flash evaporation device 4 in real time and facilitate real-time control of the refrigerant level of the flash evaporation device 4.

[0060] In some embodiments, the aforementioned compression device 1 can be a compressor. The compression device 1 can be an air-suspension compression device, that is, the compression device 1 is equipped with an air-suspension bearing to achieve oil-free, low-friction, high-speed operation.

[0061] In some implementations, such as Figure 1As shown, the aforementioned refrigerant circulation loop has a check valve 2 installed between the condenser 3 and the compressor 1. The check valve 2 is used to prevent the refrigerant from the condenser 3 from flowing back to the compressor 1.

[0062] In some embodiments, the present invention also provides an air conditioner that may include any of the air conditioning systems described above. Because the air conditioner uses the aforementioned air conditioning system, the present invention, through the bypass mechanism 100, can selectively drive the liquid refrigerant in the evaporator 6 to flow through the bypass path 10a to the condenser 3, or drive the liquid refrigerant in the condenser 3 to flow through the bypass path 10a to the evaporator 6, thus breaking the limitation of traditional air conditioning systems that rely solely on pressure difference and gravity for passive refrigerant distribution. When the refrigerant level in the evaporator 6 is too high, the bypass mechanism 100 can be controlled to drive the liquid refrigerant in the evaporator 6 to flow to the condenser 3 through the bypass flow path 10a, thereby achieving active liquid drainage and completely solving the problems of liquid carryover and liquid slugging in the compressor suction, effectively protecting the core components of the compressor. When the refrigerant level in the evaporator 6 is too low, the bypass mechanism 100 can be controlled to drive the liquid refrigerant in the condenser 3 to flow to the evaporator 6 through the bypass flow path 10a, thereby achieving active liquid replenishment, ensuring the heat exchange efficiency of the evaporator 6 and the stability of the compressor suction flow, and preventing abnormal shutdown due to low pressure protection. This overcomes the technical defect in existing air conditioning systems where the evaporator 6 cannot actively replenish or drain refrigerant under extreme conditions of excessively high or low refrigerant levels.

[0063] It should be noted that the aforementioned air conditioner can specifically be a water chiller unit, which is suitable for water chiller unit operating conditions in large and medium-sized buildings and industrial refrigeration, and has a wide range of applications and strong versatility.

[0064] In some embodiments, the present invention also provides a control method for an air conditioning system according to any one of the above-described methods, comprising the following steps: when the refrigerant level in the evaporator 6 is higher than a preset upper limit level, controlling the bypass mechanism 100 to drive the liquid refrigerant in the evaporator 6 to flow through the bypass flow path 10a to the condenser 3, until the refrigerant level in the evaporator 6 drops to a preset level range. And / or, when the refrigerant level in the evaporator 6 is lower than a preset lower limit level, controlling the bypass mechanism 100 to drive the liquid refrigerant in the condenser 3 to flow through the bypass flow path 10a to the evaporator 6, until the refrigerant level in the evaporator 6 rises back to the preset level range.

[0065] In the above example, the present invention achieves bidirectional self-regulation of refrigerant level in evaporator 6 through bypass flow path 10a: when the level is too high, liquid is discharged outward; when the level is too low, liquid is replenished in the reverse direction, dynamically balancing the refrigerant storage inside the unit and always maintaining the optimal heat exchange level of evaporator 6. This avoids the risk of compressor liquid return and slugging caused by excessively high liquid level, and also prevents insufficient heat exchange area and reduced cooling / heating capacity of the unit due to excessively low liquid level. No additional liquid storage container is required, and the system structure is simpler.

[0066] In some embodiments, when a flash evaporator 4 is connected in series between the condenser 3 and the evaporator 6 in the refrigerant circulation loop, and the compression device 1 has a gas inlet 1a, and the gas outlet 41 of the flash evaporator and the gas inlet 1a of the compression device can be connected or disconnected, if the refrigerant level of the flash evaporator 4 is greater than or equal to the preset alarm level, the connection between the gas outlet 41 of the flash evaporator and the gas inlet 1a of the compression device is cut off; otherwise, the connection between the gas outlet 41 of the flash evaporator and the gas inlet 1a of the compression device is opened.

[0067] In the above example, the liquid level inside the flash evaporator 4 can be monitored in real time. When the liquid level is too high, the gas supply passage is automatically cut off to prevent liquid refrigerant from entering the compressor unit 1 with the gas supply flow after liquid accumulates in the flash evaporator 4, effectively avoiding the risk of liquid hammer damage on the gas supply side of the compressor unit 1. When the liquid level is normal, the gas supply passage is automatically opened to maintain the gas supply enthalpy increase operation mode, taking into account both the unit's operational reliability and heat exchange efficiency under wide operating conditions.

[0068] In some embodiments, when the throttling device 5 includes a first throttling valve 51, which is disposed between the condenser 3 and the flash evaporator 4, and the first throttling valve 51 is used to regulate the refrigerant flow rate from the condenser 3 into the flash evaporator 4, if the refrigerant level in the flash evaporator 4 is higher than the target level, the opening of the first throttling valve 51 is reduced; otherwise, the opening of the first throttling valve 51 is increased. The aforementioned preset alarm level is greater than the target level.

[0069] In the above example, the liquid inlet of the flash evaporator 4 is closed-loop regulated by the first throttle valve 51 to keep the liquid level of the flash evaporator 4 stable within the target liquid level range, ensuring sufficient gas-liquid separation of the refrigerant. The gas supply branch outputs dry saturated gaseous refrigerant, ensuring stable gas supply enthalpy increase effect. When the liquid level is too high, the liquid inlet is reduced to avoid liquid accumulation, reducing the risk of liquid carryover during gas supply from the source. Combined with the high liquid level cut-off gas supply protection logic, a double anti-liquid slugging protection is formed to improve the reliability of compressor operation.

[0070] Additional explanation is needed: The aforementioned target liquid level can be a single fixed liquid level point or a liquid level range. Specifically, if the target liquid level is in the form of a range, "the refrigerant level of flash evaporator 4 is higher than the target liquid level" means that the refrigerant level of flash evaporator 4 is higher than the upper limit of the target liquid level range; correspondingly, "the refrigerant level of flash evaporator 4 is lower than the target liquid level" means that the refrigerant level of flash evaporator 4 is lower than the lower limit of the target liquid level range. "The preset alarm liquid level is higher than the target liquid level" means that the preset alarm liquid level is higher than the upper limit of the target liquid level range.

[0071] This invention can control the refrigerant level in the evaporator 6, preventing excessively high refrigerant levels in the evaporator 6 from causing liquid to be drawn into the compressor 1, and preventing excessively low refrigerant levels from causing low-pressure protection in the compressor 1. This invention can also control the refrigerant level in the condenser 3, preventing excessively high refrigerant levels in the condenser 3 from causing high-pressure protection in the compressor 1, and preventing excessively low refrigerant levels from causing cooling system failure in the air conditioning unit.

[0072] The aforementioned bypass mechanism 100 is equivalent to a refrigerant balance control system, enabling the migration of liquid refrigerant from the evaporator 6 to the condenser 3, or vice versa, thus achieving active control of the refrigerant level. When the refrigerant level in the evaporator 6 is higher than the preset upper limit level, the bypass mechanism 100 activates, the pump 7 opens, the fourth control valve 111 opens, the first control valve 81 opens, the third control valve 101 closes, and the second control valve 91 closes, enabling the refrigerant to migrate from the evaporator 6 to the condenser 3. When the refrigerant level in the evaporator 6 is lower than the preset lower limit level, the bypass mechanism 100 activates, the pump 7 opens, the fourth control valve 111 closes, the first control valve 81 closes, the third control valve 101 opens, and the second control valve 91 opens, enabling the refrigerant to migrate from the condenser 3 to the evaporator 6.

[0073] After the compressor unit 1 starts, the opening of the first throttle valve 51 is adjusted to control the amount of refrigerant entering the flash evaporator 4, keeping the actual liquid level in the flash evaporator 4 at the target level. When the actual liquid level is higher than the target level, the first throttle valve 51 closes slightly; when the actual liquid level is lower than the target level, the first throttle valve 51 opens wider. An alarm level (alarm level > target level) is set for the flash evaporator 4. When the actual liquid level in the flash evaporator 4 is ≥ the alarm level, the gas supply control valve 14 closes, cutting off the gas supply channel of the compressor unit 1. This prevents the gas supply to the compressor unit 1 from carrying liquid due to an excessively high liquid level in the flash evaporator 4, which could damage the air suspension bearing of the compressor unit 1.

[0074] Through the above-described technical solution, under full operating conditions of the air conditioning unit, this invention monitors and controls the refrigerant levels of the evaporator 6, condenser 3, and flash evaporator 4 throughout the entire process by detecting the refrigerant levels of the evaporator 6 and flash evaporator 4, and through corresponding system design and control switching. This achieves active and stable control of the refrigerant levels of the evaporator 6, condenser 3, and flash evaporator 4, avoiding excessively high or low refrigerant levels that could cause surge, high-pressure maintenance, low-pressure protection, cooling failure, or liquid-laden suction or liquid-laden replenishment in the compressor unit 1. This greatly improves the reliability and safety of the unit's operation.

[0075] This invention improves the operational reliability of air conditioning units by controlling the refrigerant levels of the evaporator 6 and condenser 3 to appropriate positions, thus avoiding problems such as surge, high pressure maintenance, low pressure protection, cooling failure, and liquid carryover caused by excessively high or low liquid levels. This invention also prevents damage to the air suspension bearing of the air suspension compressor 1 due to liquid carryover during intake or replenishment, thereby improving the operational reliability of air conditioning units and avoiding significant economic losses.

[0076] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. An air conditioning system, characterized in that: It includes a compressor (1), a condenser (3), a throttling device (5), and an evaporator (6) that are connected end to end to form a refrigerant circulation loop; The air conditioning system further includes a bypass mechanism (100), which forms a bypass flow path (10a) between the condenser (3) and the evaporator (6). The bypass mechanism (100) is used to selectively drive the liquid refrigerant in the evaporator (6) to flow through the bypass flow path (10a) to the condenser (3) so that the bypass mechanism (100) is in a first state; or drive the liquid refrigerant in the condenser (3) to flow through the bypass flow path (10a) to the evaporator (6) so that the bypass mechanism (100) is in a second state. The compression device is an air suspension compression device; When the refrigerant level in the evaporator (6) is higher than the preset upper limit level, the bypass mechanism (100) is controlled to drive the liquid refrigerant in the evaporator (6) to flow through the bypass flow path (10a) to the condenser (3) until the refrigerant level in the evaporator (6) drops to the preset level range.

2. The air conditioning system according to claim 1, characterized in that: The bypass mechanism (100) includes a pump body (7) and a bypass reversing flow channel (10a1). The bypass mechanism (100) connects the condenser (3) and the evaporator (6) through the bypass reversing flow channel (10a1) to form the bypass flow path (10a) between the condenser (3) and the evaporator (6). The pump body (7) is disposed in the bypass reversing flow channel (10a1). The bypass reversing channel (10a1) is used to control the flow direction of the internal refrigerant, so that in the first state, the inlet (71) of the pump body is connected to the evaporator (6) and the outlet (72) of the pump body is connected to the condenser (3), so that the bypass mechanism (100) can drive the liquid refrigerant in the evaporator (6) through the bypass channel (10a) to the condenser (3) through the pump body (7); and in the second state, the inlet (71) of the pump body is connected to the condenser (3) and the outlet (72) of the pump body is connected to the evaporator (6), so that the bypass mechanism (100) can drive the liquid refrigerant in the condenser (3) through the bypass channel (10a) to the evaporator (6) through the pump body (7).

3. The air conditioning system according to claim 2, characterized in that: The bypass reversing flow channel (10a1) includes a first flow channel (8), a second flow channel (9), a third flow channel (10), and a fourth flow channel (11); the inlet (71) of the pump body is connected to the evaporator (6) through the first flow channel (8) and to the condenser (3) through the second flow channel (9); the outlet (72) of the pump body is connected to the evaporator (6) through the third flow channel (10) and to the condenser (3) through the fourth flow channel (11); Each of the first flow channel (8), the second flow channel (9), the third flow channel (10), and the fourth flow channel (11) can be opened or closed.

4. The air conditioning system according to claim 3, characterized in that: The first flow channel (8) is provided with a first control valve (81), and the first flow channel (8) is opened or closed by the first control valve (81); And / or, a second control valve (91) is provided on the second flow channel (9), and the second flow channel (9) is opened or closed by the second control valve (91); And / or, the third flow channel (10) is provided with a third control valve (101), and the third flow channel (10) is opened or closed by the third control valve (101); And / or, the fourth flow channel (11) is provided with a fourth control valve (111), and the fourth flow channel (11) is opened or closed by the fourth control valve (111).

5. The air conditioning system according to claim 3 or 4, characterized in that: In the first state, both the first flow channel (8) and the fourth flow channel (11) are open, and both the second flow channel (9) and the third flow channel (10) are closed; In the second state, the first flow channel (8) and the fourth flow channel (11) are both closed, and the second flow channel (9) and the third flow channel (10) are both open.

6. The air conditioning system according to claim 3 or 4, characterized in that: The fourth flow channel (11) is provided with a one-way flow mechanism (12), which is used to block the refrigerant in the condenser (3) from flowing back to the pump body (7) through the fourth flow channel (11).

7. The air conditioning system according to claim 3 or 4, characterized in that: The bypass mechanism (100) further includes a filter (13), and the first flow channel (8) and the second flow channel (9) are both connected to the inlet (71) of the pump body through the filter (13).

8. The air conditioning system according to any one of claims 1-4, characterized in that: The refrigerant circulation loop is connected in series between the condenser (3) and the evaporator (6) with a flash evaporator (4). The compression device (1) has a gas inlet (1a). The gas outlet (41) of the flash evaporator and the gas inlet (1a) of the compression device can be connected or disconnected.

9. The air conditioning system according to claim 8, characterized in that: The throttling device (5) includes a first throttling valve (51), which is disposed between the condenser (3) and the flash evaporator (4). The first throttling valve (51) is used to regulate the refrigerant flow from the condenser (3) into the flash evaporator (4).

10. An air conditioner, characterized in that: The air conditioning system included in any one of claims 1-9.

11. A control method for an air conditioning system according to any one of claims 1-9, characterized in that: Includes the following steps: When the refrigerant level in the evaporator (6) is lower than the preset lower limit level, the bypass mechanism (100) is controlled to drive the liquid refrigerant in the condenser (3) to flow through the bypass flow path (10a) to the evaporator (6) until the refrigerant level in the evaporator (6) rises back to the preset level range.

12. The control method according to claim 11, characterized in that: When the refrigerant circulation loop is further connected in series with a flash evaporator (4) between the condenser (3) and the evaporator (6), and the compression device (1) has a gas inlet (1a), and the gas outlet (41) of the flash evaporator and the gas inlet (1a) of the compression device can be connected or disconnected, If the refrigerant level of the flash ignition device (4) is greater than or equal to the preset alarm level, the connection between the outlet (41) of the flash ignition device and the air supply port (1a) of the compression device is cut off; otherwise, the connection between the outlet (41) of the flash ignition device and the air supply port (1a) of the compression device is opened.

13. The control method according to claim 12, characterized in that: When the throttling device (5) includes a first throttling valve (51), which is disposed between the condenser (3) and the flash evaporator (4), and the first throttling valve (51) is used to regulate the refrigerant flow rate from the condenser (3) into the flash evaporator (4), If the refrigerant level of the flash device (4) is higher than the target level, the opening of the first throttle valve (51) is reduced; otherwise, the opening of the first throttle valve (51) is increased. The preset alarm level is higher than the target level.

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