Water chiller, air conditioner and control method thereof

Abstract

The application discloses a water chiller, an air conditioner and a control method thereof. The water chiller comprises a frequency converter power module, a compressor motor module, an evaporator, a condenser and a heat exchange module. The heat exchange module has a first flow channel and a second flow channel. The first flow channel is connected with a chilled water inlet and a chilled water outlet of the evaporator. An inlet of the second flow channel is connected with a refrigerant outlet of the condenser. An outlet of the second flow channel is connected with a liquid cooling radiator of the frequency converter power module and the compressor motor module through a throttling element. The chilled water is introduced to supercool the liquid refrigerant, the refrigerating capacity of the cooling pipeline is effectively improved, the overtemperature problems of the frequency converter and the compressor motor under the low pressure ratio working condition are solved, and the operation reliability of the unit is improved.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to a chiller unit, an air conditioner, and a control method thereof. Background Technology

[0002] Centrifugal chillers are core equipment in large central air conditioning systems, and their operational reliability directly affects the stability of the entire refrigeration system. In variable frequency centrifugal chillers, the compressor motor and inverter power module are key components for unit operation. They generate a large amount of heat during operation, which needs to be controlled within a suitable range through a cooling system to ensure long-term operational reliability.

[0003] Currently, variable frequency chiller units generally use their own refrigerant to exchange heat and cool the compressor motor and inverter power module. Specifically, this cooling method involves taking high-temperature, high-pressure liquid refrigerant from the condenser's bottom collection tank, and using the system's high pressure difference to introduce the liquid refrigerant into the inverter power module's cold plate and the compressor motor cavity. Through the exchange of latent heat and sensible heat by the refrigerant, the heat dissipated by the inverter power module and motor windings is carried away.

[0004] However, the above cooling scheme still has the following shortcomings in actual operation. First, during spring and autumn seasons or in the early morning and evening, when the heat load is low, the unit operates at a relatively low pressure, resulting in insufficient high and low pressure differentials in the system. This leads to a reduction in the amount of liquid supplied to the cooling pipes, which cannot effectively remove the heat generated by the inverter and compressor motor, easily triggering over-temperature protection abnormalities and affecting the normal operation of the unit. Second, in special circumstances such as unit failure, emergency shutdown, or sudden power outage, the system pressure differential disappears instantly, the liquid supply to the cooling pipes is interrupted, and the compressor motor windings and inverter power modules remain at a high temperature due to thermal inertia. This can cause a sharp temperature rise in a short time, triggering a fault alarm. In severe cases, it may damage electrical components and affect the long-term operational reliability of the unit. Summary of the Invention

[0005] The embodiments of the present invention provide a chiller unit, an air conditioner and a control method thereof, which aim to solve the technical problem of over-temperature protection of the frequency converter and compressor motor caused by insufficient liquid supply in existing centrifugal chiller units under low pressure ratio conditions.

[0006] In a first aspect, the present invention provides a chiller unit, comprising: a frequency converter power module thermally coupled to a first liquid-cooled radiator; a compressor motor module thermally coupled to a second liquid-cooled radiator; an evaporator having a chilled water inlet and a chilled water outlet; a condenser having a refrigerant outlet for discharging liquid refrigerant; and a heat exchange module having a first flow channel and a second flow channel for mutual heat exchange, wherein the inlet of the first flow channel is connected to the chilled water inlet, and the outlet is connected to the chilled water outlet; the inlet of the second flow channel is connected to the refrigerant outlet, and the outlet is connected to the first liquid-cooled radiator and the second liquid-cooled radiator respectively through a throttling element.

[0007] Furthermore, it also includes a liquid storage module, and the condenser also has a liquid replenishment port for discharging liquid refrigerant. The inlet of the liquid storage module is connected to the liquid replenishment port, and the outlet of the liquid storage module is connected to the inlet of the second flow channel.

[0008] Furthermore, it also includes a first one-way valve, which is connected in series in the flow path between the inlet of the liquid storage module and the replenishment port. The inlet of the first one-way valve is connected to the replenishment port, and the outlet of the first one-way valve is connected to the inlet of the liquid storage module.

[0009] Furthermore, it also includes a second one-way valve, which is connected in series in the flow path between the refrigerant outlet and the inlet of the second flow channel. The inlet of the second one-way valve is connected to the refrigerant outlet, and the outlet of the second one-way valve is connected to the inlet of the second flow channel.

[0010] Furthermore, the throttling element includes a first expansion valve and a second expansion valve, the outlet of the second flow channel is connected to the inlet of the first liquid cooler through the first expansion valve, and the outlet of the second flow channel is connected to the inlet of the second liquid cooler through the second expansion valve.

[0011] Furthermore, it also includes a solenoid valve, which is connected in series in the flow path between the inlet of the first flow channel and the chilled water inlet.

[0012] Furthermore, it also includes a filter connected in series in the flow path between the inlet of the first flow channel and the chilled water inlet.

[0013] Furthermore, it also includes a flow regulating valve, which is connected in series in the flow path between the outlet of the first flow channel and the chilled water outlet.

[0014] Furthermore, the refrigerant outlets of the first liquid-cooled radiator and the second liquid-cooled radiator are combined and connected to the inlet of the evaporator.

[0015] In a second aspect, the present invention provides an air conditioner comprising the chiller unit described in the first aspect above.

[0016] Thirdly, the present invention provides an air conditioning control method applied to the air conditioner described in the second aspect above. The method includes: obtaining the current operating pressure ratio of a chiller unit; if the current operating pressure ratio is less than a preset pressure ratio threshold, determining a target frequency based on the current operating pressure ratio and a preset maximum frequency curve; controlling the compressor of the chiller unit to operate at the target frequency, wherein the preset maximum frequency curve is obtained by shifting the anti-surge line of the chiller unit upwards; obtaining the cooling capacity of the chiller unit; if the cooling capacity does not meet preset conditions, controlling the compressor of the chiller unit to increase its operating frequency according to a preset frequency increase rate, and controlling the heat exchange module to dissipate heat from the inverter power module and the compressor motor module.

[0017] Compared with existing technologies, the chiller unit of this application, by setting up a heat exchange module with a first flow channel and a second flow channel, introduces chilled water from the evaporator into the first flow channel and liquid refrigerant from the condenser into the second flow channel. The chilled water subcools the liquid refrigerant before it is delivered to the liquid-cooled radiators of the inverter power module and compressor motor module, effectively improving the cooling capacity of the cooling pipes and solving the problem of overheating of the inverter and compressor motor due to insufficient liquid supply under low-pressure ratio conditions. Furthermore, by adding a liquid storage module and a one-way valve, liquid refrigerant storage is achieved during normal operation, as well as continuous emergency liquid supply cooling under special conditions such as malfunctions, emergency shutdowns, or power outages, avoiding a sharp temperature rise caused by cooling interruption. By combining subcooling heat dissipation with emergency cooling, the heat dissipation reliability and operational safety of the chiller unit and air conditioner are comprehensively improved under various operating conditions. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a simplified structural diagram of a chiller unit provided in an embodiment of the present invention; Figure 2 The graphs of the highest frequency curve and the anti-surge curve provided for embodiments of the present invention; Figure 3 A flowchart illustrating the steps of the method provided in this embodiment of the invention; Figure 4 A flowchart of the sub-steps of the method provided in the embodiments of the present invention; Figure 5 A flowchart of the sub-steps of the method provided in the embodiments of the present invention; Figure 6 A flowchart of the sub-steps of the method provided in the embodiments of the present invention; Explanation of reference numerals in the attached figures: 10. Inverter power module; 11. First liquid-cooled radiator; 20. Compressor motor module; 21. Second liquid-cooled radiator; 30. Evaporator; 40. Condenser; 50. Heat exchange module; 51. First flow channel; 52. Second flow channel; 60. Throttling element; 61. First expansion valve; 62. Second expansion valve; 70. Liquid storage module; 80. First check valve; 81. Second check valve; 82. Solenoid valve; 83. Filter; 84. Flow regulating valve. Detailed Implementation

[0020] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0022] Please see Figure 1 This invention provides a chiller unit, which includes a frequency converter power module 10, a compressor motor module 20, an evaporator 30, a condenser 40, and a heat exchange module 50. The frequency converter power module 10 is thermally coupled to a first liquid-cooled radiator 11; the compressor motor module 20 is thermally coupled to a second liquid-cooled radiator 2121; the evaporator 30 has a chilled water inlet a and a chilled water outlet b; the condenser 40 has a refrigerant outlet c for discharging liquid refrigerant; the heat exchange module 50 has a first flow channel 51 and a second flow channel 52 for mutual heat exchange. The inlet of the first flow channel 51 is connected to the chilled water inlet a, and the outlet is connected to the chilled water outlet b; the inlet of the second flow channel 52 is connected to the refrigerant outlet c, and the outlet is connected to the first liquid-cooled radiator 11 and the second liquid-cooled radiator 21 respectively through a throttling element 60.

[0023] In practical implementation, the chiller unit of this embodiment can be applied to large-scale central air conditioning systems (such as hospitals, shopping malls, airports, subways, etc.) to provide cooling capacity for terminal air conditioning equipment. The chiller unit can be a centrifugal water-cooled unit. Its basic refrigeration principle is that the compressor compresses the refrigerant. The high-temperature and high-pressure gaseous refrigerant enters the condenser 40, releases heat to the outside, and condenses into a liquid state. After the liquid refrigerant is throttled and depressurized, it enters the evaporator 30, where it absorbs heat from the chilled water and evaporates. After the chilled water temperature decreases, it is transported to the terminal air conditioning equipment for cooling. The evaporated gaseous refrigerant then returns to the compressor to complete the cycle.

[0024] The chiller unit in this embodiment includes an inverter power module 10, a compressor motor module 20, an evaporator 30, a condenser 40, and a heat exchange module 50. The inverter power module 10 and the compressor motor module 20 are the core drive and control components of the chiller unit, generating a large amount of heat during operation. This heat must be dissipated promptly through a cooling system to ensure it operates within a safe temperature range. A first liquid-cooled radiator 11 is thermally coupled to the inverter power module 10, and a second liquid-cooled radiator 21 is thermally coupled to the compressor motor module 20. The refrigerant flowing through the radiators absorbs and removes heat from the corresponding components, achieving effective temperature control. Both the evaporator 30 and the condenser 40 are shell-and-tube structures. The evaporator 30 serves as the cooling end of the chiller unit, with its chilled water inlet a and chilled water outlet b connected to external chilled water pipelines. The chilled water cools down after exchanging heat with the refrigerant within the evaporator 30 and is then delivered to the terminal equipment for cooling. The condenser 40 is used to condense the high-temperature and high-pressure gaseous refrigerant discharged from the compressor into liquid refrigerant, and its refrigerant outlet c outputs high-temperature and high-pressure liquid refrigerant.

[0025] The heat exchange module 50, a key component of this solution, is a plate heat exchanger with a first flow channel 51 and a second flow channel 52 for mutual heat exchange. Both the first and second flow channels 51 and 52 have an inlet (m in the figure) and an outlet (n in the figure). The inlet of the first flow channel 51 is connected to the chilled water inlet a of the evaporator 30, and the outlet of the first flow channel 51 is connected to the chilled water outlet b of the evaporator 30. Thus, the pressure difference between the inlet and outlet of the evaporator 30 drives a portion of the low-temperature chilled water to flow through the first flow channel 51. The inlet of the second flow channel 52 is connected to the refrigerant outlet c of the condenser 40, and the high-temperature, high-pressure liquid refrigerant enters the second flow channel 52. Between the first flow channel 51 and the second flow channel 52, the low-temperature chilled water and the high-temperature liquid refrigerant exchange sensible heat, resulting in the liquid refrigerant output from the outlet of the second flow channel 52 being subcooled, with a significantly lower temperature than the conventional direct liquid extraction method. The subcooled low-temperature liquid refrigerant is delivered to the first liquid-cooled radiator 11 and the second liquid-cooled radiator 21 via the throttling element 60. The latent heat and sensible heat of the refrigerant are used to dissipate heat from the inverter power module 10 and the compressor motor module 20. Compared to the conventional method of direct cooling with high-temperature liquid refrigerant, this solution effectively improves the heat exchange capacity under the same conditions through chilled water subcooling, ensuring that the unit can maintain the temperature of the inverter power module 10 and the compressor motor module 20 within a reasonable range even under low pressure ratio conditions.

[0026] Through the above structural design, the chiller unit in this embodiment retains the basic architecture of the conventional refrigerant cooling system, and achieves subcooling of liquid refrigerant by adding a heat exchange module 50 and introducing a chilled water bypass flow path. With a simple and reliable structure, it improves the cooling capacity under low pressure ratio conditions and ensures the stable operation and long-term reliability of the unit.

[0027] In one embodiment, see Figure 1 The chiller unit also includes a liquid storage module 70, and the condenser 40 also has a liquid replenishment port d for outputting liquid refrigerant. The inlet of the liquid storage module 70 is connected to the liquid replenishment port d, and the outlet of the liquid storage module 70 is connected to the inlet of the second flow channel 52.

[0028] In practice, the liquid storage module 70 is used to store a certain amount of high-pressure liquid refrigerant during normal unit operation. In addition to the refrigerant outlet c, the bottom of the condenser 40 is also equipped with a liquid replenishment port d, which is connected to the inlet of the liquid storage module 70. This allows some of the high-pressure liquid refrigerant condensed in the condenser 40 to flow into the liquid storage module 70 for storage via the liquid replenishment port d. The outlet of the liquid storage module 70 is connected to the inlet of the second flow channel 52 of the heat exchange module 50, allowing the liquid refrigerant in the liquid storage module 70 to also enter the heat exchange module 50 and be further supplied to the first liquid-cooled radiator 11 and the second liquid-cooled radiator 21.

[0029] When the unit malfunctions, shuts down urgently, or experiences a sudden power outage, the high and low pressure difference in the system disappears rapidly, and the normal liquid supply to the refrigerant outlet c of the condenser 40 decreases sharply or even stops. At this time, the high-pressure liquid refrigerant stored in the liquid receiver module 70 continuously supplies liquid to the second flow channel 52 and the downstream liquid-cooled radiator using its own pressure, providing continuous cooling for the inverter power module 10 and the compressor motor module 20, preventing over-temperature protection from being triggered or electrical components from being damaged due to a sudden temperature rise caused by cooling interruption. The volume of the liquid receiver module 70 can be designed according to the unit's power and cooling requirements to ensure that it can provide sufficient emergency cooling liquid for a sufficient duration and quantity after shutdown.

[0030] This embodiment adds a liquid storage module 70 and connects the liquid supply port d of the condenser 40 to the liquid storage module 70, thereby realizing high-pressure liquid storage during normal operation of the unit, as well as continuous emergency liquid supply cooling for the inverter power module 10 and the compressor motor module 20 under special conditions such as faults, emergency shutdowns or power outages. This effectively avoids the problem of a sharp temperature rise caused by cooling interruption and improves the safety and reliability of the unit operation.

[0031] Further, see Figure 1 The chiller unit also includes a first one-way valve 80, which is connected in series in the flow path between the inlet of the liquid storage module 70 and the liquid replenishment port d. The inlet of the first one-way valve 80 is connected to the liquid replenishment port d, and the outlet of the first one-way valve 80 is connected to the inlet of the liquid storage module 70.

[0032] In practice, the first one-way valve 80 is installed on the connecting pipeline between the liquid inlet d of the condenser 40 and the inlet of the liquid storage module 70, with its conduction direction being unidirectional from the condenser 40 to the liquid storage module 70. When the chiller unit is operating normally, the high-pressure liquid refrigerant in the condenser 40 flows out through the liquid inlet d, pushes open the first one-way valve 80, and enters the liquid storage module 70 for storage. When the unit malfunctions, shuts down in an emergency, or experiences a sudden power outage, the system pressure difference decreases or disappears, and the pressure on the condenser 40 side may be lower than the pressure inside the liquid storage module 70. At this time, the first one-way valve 80 automatically closes, preventing the liquid refrigerant in the liquid storage module 70 from flowing back to the condenser 40, thereby ensuring that the liquid refrigerant in the liquid storage module 70 can only flow through the outlet towards the heat exchange module 50 and the downstream liquid-cooled radiator, achieving continuous emergency cooling of the inverter power module 10 and the compressor motor module 20 after shutdown.

[0033] This embodiment connects a first one-way valve 80 in series between the inlet of the liquid storage module 70 and the liquid replenishment port d of the condenser 40. By utilizing the one-way conduction characteristic of the one-way valve, it ensures that the liquid refrigerant can only flow from the condenser 40 to the liquid storage module 70. Under the condition that the pressure difference disappears when the unit is shut down, it effectively prevents the high-pressure liquid refrigerant in the liquid storage module 70 from flowing back, thus ensuring the reliability and effectiveness of emergency cooling liquid supply.

[0034] In one embodiment, see Figure 1 The chiller unit also includes a second one-way valve 81, which is connected in series in the flow path between the refrigerant outlet c and the inlet of the second flow channel 52. The inlet of the second one-way valve 81 is connected to the refrigerant outlet c, and the outlet of the second one-way valve 81 is connected to the inlet of the second flow channel 52.

[0035] In specific implementation, the second one-way valve 81 is installed on the connecting pipe between the refrigerant outlet c of the condenser 40 and the inlet of the second flow channel 52 of the heat exchange module 50, with its conduction direction being unidirectional from the condenser 40 to the second flow channel 52. When the chiller unit is operating normally, the high-pressure liquid refrigerant in the condenser 40 flows out through the refrigerant outlet c, pushes open the second one-way valve 81, enters the second flow channel 52, and exchanges heat with the low-temperature chilled water in the first flow channel 51 in the heat exchange module 50, thereby achieving subcooling of the liquid refrigerant. When the unit malfunctions, shuts down in an emergency, or suddenly loses power, the system pressure difference drops rapidly or disappears. The pressure on the condenser 40 side may be lower than the pressure in the second flow channel 52 and downstream pipeline. At this time, the second check valve 81 automatically closes under the action of reverse pressure difference, preventing the liquid refrigerant in the second flow channel 52 and downstream pipeline from flowing back to the condenser 40. This keeps a certain amount of liquid refrigerant in the downstream pipeline, providing residual cooling for a certain period of time for the inverter power module 10 and the compressor motor module 20, and slowing down the rate of temperature rise.

[0036] This embodiment connects a second one-way valve 81 in series between the refrigerant outlet c of the condenser 40 and the inlet of the second flow channel 52. By utilizing the one-way conduction characteristic of the one-way valve, the normal supply of refrigerant to the heat exchange module 50 is ensured during normal operation of the unit. Under conditions such as shutdown and disappearance of pressure difference, the reverse flow of downstream refrigerant is effectively prevented, the temperature rise of the inverter power module 10 and the compressor motor module 20 is delayed, and the operational safety of the unit under special conditions is improved.

[0037] In one embodiment, see Figure 1 The throttling element 60 includes a first expansion valve 61 and a second expansion valve 62. The outlet of the second flow channel 52 is connected to the inlet of the first liquid cooler 11 through the first expansion valve 61, and the outlet of the second flow channel 52 is connected to the inlet of the second liquid cooler 21 through the second expansion valve 62.

[0038] In specific implementation, the throttling element 60 adopts a dual expansion valve split design, that is, the first expansion valve 61 and the second expansion valve 62 are independently set on the connecting pipe between the outlet of the second flow channel 52 and the two liquid-cooled radiators. The first expansion valve 61 is connected in series between the outlet of the second flow channel 52 and the inlet of the first liquid-cooled radiator 11 to regulate the refrigerant flow rate entering the first liquid-cooled radiator 11; the second expansion valve 62 is connected in series between the outlet of the second flow channel 52 and the inlet of the second liquid-cooled radiator 21 to regulate the refrigerant flow rate entering the second liquid-cooled radiator 21.

[0039] After being subcooled by the heat exchange module 50, the low-temperature liquid refrigerant flows out from the outlet of the second flow channel 52 and enters the first expansion valve 61 and the second expansion valve 62 respectively. Both the first expansion valve 61 and the second expansion valve 62 can be electronic expansion valves, and the flow rate of the refrigerant can be controlled by adjusting the valve opening. After being throttled and depressurized by the first expansion valve 61, the refrigerant enters the first liquid-cooled radiator 11 to absorb the heat generated by the inverter power module 10; after being throttled and depressurized by the second expansion valve 62, the refrigerant enters the second liquid-cooled radiator 21 to absorb the heat generated by the compressor motor module 20. Since the heat generation and temperature change characteristics of the inverter power module 10 and the compressor motor module 20 are different, the independent first expansion valve 61 and second expansion valve 62 are used to control the refrigerant supply of the two circuits respectively. The cooling intensity can be precisely adjusted according to the real-time temperature feedback of each circuit, realizing differentiated temperature control and avoiding the problems of overcooling or insufficient cooling caused by uniform liquid supply.

[0040] This embodiment sets the throttling element 60 as the first expansion valve 61 and the second expansion valve 62 corresponding to the first liquid-cooled radiator 11 and the second liquid-cooled radiator 21, respectively, to achieve independent adjustment of the cooling flow of the inverter power module 10 and the compressor motor module 20. This enables the two cooling circuits to perform differentiated and precise temperature control according to their actual temperature conditions, thereby improving the cooling system's ability to adjust to the differences in heat generation of various components under different operating conditions and its temperature control accuracy.

[0041] In one embodiment, see Figure 1 The chiller unit also includes a solenoid valve 82, which is connected in series in the flow path between the inlet of the first flow channel 51 and the chilled water inlet a.

[0042] In practice, the solenoid valve 82 is installed on the connecting pipe between the inlet of the first flow channel 51 of the heat exchange module 50 and the chilled water inlet a of the evaporator 30. The solenoid valve 82 acts as the on / off control element for the chilled water bypass flow path, selectively opening or closing the bypass flow path according to the actual operating conditions of the chiller unit. When the chiller unit operates under low pressure ratio conditions, and the temperature of the inverter power module 10 or compressor motor module 20 rises requiring auxiliary cooling, the control system controls the solenoid valve 82 to open. The pressure difference between the inlet and outlet of the evaporator 30 drives a portion of the low-temperature chilled water through the solenoid valve 82 into the first flow channel 51, where it exchanges heat with the high-temperature liquid refrigerant in the second flow channel 52 to achieve refrigerant subcooling and enhance the cooling effect. When the chiller unit operates under normal conditions or when no chilled water auxiliary cooling is required, the solenoid valve 82 remains closed, cutting off the chilled water bypass flow path. All chilled water flows through the evaporator 30 to participate in the main refrigeration cycle, avoiding unnecessary cold energy diversion.

[0043] This embodiment connects a solenoid valve 82 in series in the flow path between the inlet of the first flow channel 51 and the chilled water inlet a, thereby realizing the on-demand on-off control of the chilled water bypass flow path. This allows the heat exchange module 50 to operate only when auxiliary cooling is needed, avoiding the ineffective loss of chilled water cooling capacity under normal operating conditions. This improves the cooling capacity under low pressure ratio conditions while taking into account the overall energy efficiency of the unit.

[0044] In one embodiment, see Figure 1 The chiller unit also includes a filter 83, which is connected in series in the flow path between the inlet of the first flow channel 51 and the chilled water inlet a.

[0045] In specific implementation, filter 83 is installed on the connecting pipe between the inlet of the first flow channel 51 of heat exchange module 50 and the chilled water inlet a of evaporator 30. Filter 83 is used to filter the chilled water entering the first flow channel 51, removing impurities and particulate matter that may be present in the chilled water. Because the cross-sectional area of ​​the internal flow channels of the first flow channel 51 and the second flow channel 52 of heat exchange module 50 is small, there are certain requirements for water cleanliness. If impurities in the chilled water enter the first flow channel 51, long-term operation may lead to flow channel blockage or a decrease in heat exchange efficiency, affecting the subcooling effect. Filter 83 can purify the chilled water before it enters the first flow channel 51, ensuring the cleanliness of the chilled water flowing through heat exchange module 50 and maintaining the long-term stable operation and high-efficiency heat exchange performance of heat exchange module 50.

[0046] This embodiment effectively intercepts impurities in the chilled water by connecting a filter 83 in series in the flow path between the inlet of the first flow channel 51 and the chilled water inlet a, protecting the cleanliness of the flow path inside the heat exchange module 50, ensuring long-term stability of heat exchange efficiency, and extending the service life of the heat exchange module 50 and downstream cooling pipe components.

[0047] In one embodiment, see Figure 1 The chiller unit also includes a flow regulating valve 84, which is connected in series in the flow path between the outlet of the first flow channel 51 and the chilled water outlet b.

[0048] In practice, the flow regulating valve 84 is installed on the connecting pipe between the outlet of the first flow channel 51 of the heat exchange module 50 and the chilled water outlet b of the evaporator 30. The flow regulating valve 84 is used to regulate the flow rate of chilled water flowing through the first flow channel 51. When the chiller unit is operating under low pressure ratio conditions and requires auxiliary cooling, the solenoid valve 82 opens, and the chilled water bypass flow path is opened. At this time, the control system can adjust the opening degree of the flow regulating valve 84 to control the chilled water flow rate according to the actual temperature of the inverter power module 10 and the compressor motor module 20. When the opening degree increases, the flow rate of chilled water flowing through the first flow channel 51 increases, and the heat exchange with the liquid refrigerant in the second flow channel 52 increases accordingly, the refrigerant subcooling degree increases, and the cooling capacity is enhanced; when the opening degree decreases, the chilled water flow rate decreases, and the refrigerant subcooling degree decreases accordingly. Through the fine adjustment of the flow regulating valve 84, the cooling demand can be met while avoiding excessive chilled water outflow that would affect the main refrigeration cycle efficiency of the evaporator 30.

[0049] This embodiment achieves precise control of the bypass flow rate of chilled water by connecting a flow regulating valve 84 in series on the flow path between the outlet of the first flow channel 51 and the chilled water outlet b. This allows the subcooling capacity of the heat exchange module 50 to be flexibly adjusted according to the actual heat dissipation requirements, ensuring the cooling effect while taking into account the overall energy efficiency of the unit.

[0050] In one embodiment, see Figure 1 The refrigerant outlets f of the first liquid-cooled radiator 11 and the second liquid-cooled radiator 21 are merged and connected to the inlet of the evaporator 30.

[0051] In specific implementation, such as Figure 1 As shown, both the first liquid-cooled radiator 11 and the second liquid-cooled radiator 2121 have a refrigerant inlet e and a refrigerant outlet f. A throttling element 60 is connected to the refrigerant inlet e to provide refrigerant for heat dissipation. The refrigerant outlet f of the first liquid-cooled radiator 11 and the refrigerant outlet f of the second liquid-cooled radiator 21 are connected to the refrigerant inlet g of the evaporator 30 via pipelines. During the flow of the liquid refrigerant through the first liquid-cooled radiator 11 and the second liquid-cooled radiator 21, the liquid refrigerant absorbs heat dissipated by the inverter power module 10 and the compressor motor module 20, respectively, and some of the liquid refrigerant evaporates into a gaseous state or a gas-liquid two-phase state. The merged refrigerant returns to the inlet of the evaporator 30, merges with the refrigerant in the main refrigeration cycle, and enters the evaporator 30 together to participate in evaporation and heat absorption, supplying cooling to the terminal, completing a closed-loop cycle between the cooling branch and the main refrigeration circuit. This design allows the refrigerant in the cooling branch to be directly incorporated into the main cycle without an additional recovery device, simplifying the system piping layout and achieving organic integration of cooling and refrigeration functions.

[0052] This embodiment connects the refrigerant outlets f of the first liquid-cooled radiator 11 and the second liquid-cooled radiator 21 to the inlet of the evaporator 30, so that the refrigerant after absorbing heat in the cooling branch directly returns to the main refrigeration cycle to participate in evaporative refrigeration, realizing the recycling of refrigerant. The system structure is simple and compact, avoiding the problem of independent recovery of refrigerant in the cooling branch.

[0053] In summary, the chiller unit provided in this application subcools the liquid refrigerant from the condenser by introducing chilled water from the evaporator into the heat exchange module, and then distributes the subcooled liquid refrigerant to the liquid-cooled radiators of the inverter power module and the compressor motor module. This improves the cooling capacity of the cooling pipes under low pressure ratio conditions, solves the problem of overheating of the inverter and compressor motor, and enhances the operational reliability of the unit.

[0054] The present invention also provides an air conditioner comprising the chiller unit described in any of the foregoing embodiments (see Figure 1 Since the specific structure and working principle of the chiller unit have been described in detail in the above embodiments, they will not be repeated here.

[0055] In practical implementation, the air conditioner, as a complete air conditioning system, includes not only the aforementioned chiller unit but also a cooling water system, a chilled water system, and a control system. The chiller unit is the core cold source equipment of the air conditioner. It drives the refrigerant circulation through a compressor, absorbing heat from the chilled water in the evaporator 30 to cool it down, and releasing the heat to the cooling water in the condenser 40, thereby continuously producing low-temperature chilled water for supply to the terminal equipment. The chiller unit used in this air conditioner has the aforementioned heat exchange module 50, which can introduce chilled water from the evaporator 30 to subcool the liquid refrigerant, improving the cooling effect of the inverter power module 10 and the compressor motor module 20 under low-pressure ratio conditions; it is also equipped with a liquid storage module 70 to provide emergency cooling in case of emergency shutdown or power failure.

[0056] The cooling water system is connected to the condenser 40 of the chiller unit and mainly includes a cooling water pump and a cooling tower. The cooling water pump drives the cooling water to circulate between the condenser 40 and the cooling tower. When the cooling water flows through the condenser 40, it absorbs the heat released by the refrigerant. After its temperature rises, it enters the cooling tower, where it exchanges heat and moisture with the outdoor air. The heat is discharged to the atmosphere, and the cooled cooling water is then pumped back to the condenser 40, forming a cooling water circulation loop.

[0057] The chilled water system is connected to the evaporator 30 of the chiller unit and mainly includes a chilled water pump and an air handling unit. The chilled water pump drives the chilled water to circulate between the evaporator 30 and the air handling unit. Low-temperature chilled water is delivered from the outlet of the evaporator 30 to each terminal air handling unit, where it exchanges heat with the indoor return air. After the air is cooled, it is sent into the indoor space for cooling. The chilled water, whose temperature has increased after heat exchange, returns to the evaporator 30 to be cooled again, forming a chilled water circulation loop.

[0058] The control system is used for centralized monitoring and regulation of the air conditioner's operating status. It can collect parameters such as the chiller's operating pressure ratio, compressor frequency, inverter power module 10 temperature, compressor motor module 20 temperature, and chilled water inlet and outlet temperatures. Based on preset logic, it automatically adjusts the compressor's start / stop and frequency, the opening degree of each expansion valve, the on / off state of solenoid valve 82, the opening degree of flow regulating valve 84, and the operating status of the cooling water pump and chilled water pump, ensuring stable, efficient, and safe operation of the air conditioner under all operating conditions.

[0059] The air conditioner of this embodiment integrates the chiller unit of the above embodiments, which can maintain reliable heat dissipation for key components under low pressure ratio and complex operating conditions, and has excellent operational stability under normal and emergency conditions, thus comprehensively improving the overall reliability, safety and applicability of the air conditioner.

[0060] Please see Figure 3 The present invention also provides an air conditioning control method, which is applied to the air conditioner described in the foregoing embodiments. This method dynamically regulates the compressor frequency and the operating status of the heat exchange module during actual operation of the unit, thereby achieving effective heat dissipation for the inverter power module and the compressor motor module. Figure 2 As shown, the air conditioning control method includes steps S110-S150.

[0061] S110, Obtain the current operating pressure ratio of the chiller unit; S120. If the current operating pressure ratio is less than the preset pressure ratio threshold, then the target frequency is determined based on the current operating pressure ratio and the preset highest frequency curve. S130. Control the compressor of the chiller unit to operate at the target frequency, wherein the preset highest frequency curve is obtained by shifting the anti-surge line of the chiller unit upwards; S140. Obtain the cooling capacity of the chiller unit; S150. If the cooling capacity does not meet the preset conditions, the compressor of the chiller unit is controlled to increase its operating frequency according to the preset frequency increase rate, and the heat exchange module is controlled to dissipate heat from the inverter power module and the compressor motor module.

[0062] In practice, this control method mainly addresses the problem of insufficient cooling of chillers under low pressure ratio conditions. It uses a graded control strategy that combines frequency limiting to reduce heat generation with auxiliary subcooling to ensure that the temperature of the inverter power module and the compressor motor module is always within a safe range.

[0063] First, the control system acquires the current operating pressure ratio of the chiller unit in real time. The operating pressure ratio, the ratio of the compressor's condensing pressure to its evaporating pressure (i.e., the ratio of discharge pressure to suction pressure), is a crucial parameter reflecting the unit's operating condition. During spring and autumn, or in the early morning and evening, when heat loads are lower, the unit's operating pressure ratio is lower. When the control system detects that the current operating pressure ratio is lower than the preset pressure ratio threshold, it indicates that the unit has entered the low-pressure ratio operating range. If it continues to operate at the rated frequency at this time, the inverter power module and compressor motor windings will generate significant heat, while the low pressure ratio will lead to insufficient cooling water supply to the cooling pipes, easily causing overheating. Therefore, the control system determines the target frequency based on the current operating pressure ratio and the preset maximum frequency curve. Figure 2 The image shows the curves of the preset highest frequency curve and the anti-surge curve. (See attached image.) Figure 2 The preset maximum frequency curve is obtained by shifting the anti-surge line of the chiller unit upwards. This means that at the same pressure ratio, the frequency value corresponding to the maximum frequency curve is higher than the minimum frequency corresponding to the anti-surge line, providing a certain safety margin. This prevents the compressor from entering the surge zone and limits the maximum operating frequency under low pressure ratio conditions, reducing heat generation in the motor windings and inverter power modules from the source. After determining the target frequency, the control system controls the compressor to operate at that target frequency, enabling the unit to operate at a limited frequency under this pressure ratio.

[0064] During frequency-limited operation, the control system continuously acquires the cooling capacity of the chiller unit. The cooling capacity is determined by comparing the chilled water outlet temperature of the evaporator with a preset temperature threshold. When the chilled water outlet temperature exceeds the preset threshold, it indicates that the current cooling capacity cannot meet the terminal load demand, and the unit needs to further increase its frequency to increase cooling output. At this time, the control system controls the compressor to increase its operating frequency according to the preset frequency increase rate, while simultaneously controlling the heat exchange module to start operation. Specifically, the control system opens the solenoid valve on the chilled water bypass pipeline and adjusts the opening of the flow regulating valve according to the temperature conditions. This allows the pressure difference between the evaporator inlet and outlet to drive a portion of the low-temperature chilled water to flow through the first flow channel of the heat exchange module, exchanging heat with the high-temperature liquid refrigerant from the condenser in the second flow channel, thus subcooling the liquid refrigerant. The subcooled low-temperature liquid refrigerant is then transported to the first and second liquid-cooled radiators via throttling elements, absorbing heat from the inverter power module and compressor motor module to achieve auxiliary heat dissipation.

[0065] This implementation adopts a graded control strategy that combines frequency limiting to reduce heat generation with chilled water subcooling to enhance heat dissipation. Under low pressure ratio conditions, the heat output of the heat source is reduced by limiting the maximum operating frequency. When the cooling demand increases and the frequency needs to be increased, the heat exchange module is put into operation simultaneously to enhance the cooling capacity. The two work together to effectively solve the problem of over-temperature protection of the frequency converter and compressor motor under low pressure ratio conditions, and improve the operational reliability of the air conditioner under complex conditions.

[0066] In one embodiment, the expression for the preset highest frequency curve is Y=A×x 3 +B×x 2 +C×x+D, where Y is the target frequency, x is the current operating pressure ratio, and A, B, C, and D are all constants.

[0067] In practice, the highest frequency curve is fitted using a cubic polynomial. The expression for this curve is Y = A × x. 3 +B×x 2 The formula is: +C×x+D, where Y represents the maximum allowable operating frequency of the compressor under the current operating pressure ratio, x represents the current operating pressure ratio of the chiller unit, and A, B, C, and D are the coefficients and constants of the polynomial. Each coefficient and constant can be determined by fitting actual test data of the unit. Specifically, the surge frequency points of the unit under different pressure ratios can be found through experimental testing. Multiple sets of pressure ratios and surge frequency data are then fitted using a polynomial to obtain the expression for the anti-surge curve. Based on this, the constant term of the polynomial corresponding to the anti-surge curve is increased, causing the curve to shift upwards, thus obtaining the expression for the preset maximum frequency curve.

[0068] See Figure 2 As a preferred value scheme, A=4.0616, B=67.392, C=287.49, D=8.1769, Y=4.0616x 3 +67.392x 2 +287.49x+8.1769. Since the constant term D is larger than the constant term of the polynomial corresponding to the anti-surge line, under the same operating pressure ratio, the target frequency value corresponding to the preset highest frequency curve is always higher than the anti-surge frequency value corresponding to the anti-surge line, which reserves a safety margin of about 100Hz for the unit, preventing the compressor from entering the surge zone and limiting the operating frequency under low pressure ratio conditions to a reasonable range.

[0069] In actual control, the control system acquires the current operating pressure ratio of the chiller unit in real time and substitutes it into the aforementioned polynomial expression for calculation, thus quickly obtaining the corresponding target frequency. For example, when the unit's rated frequency is 500Hz and the operating pressure ratio is 2.0, substituting x=2.0 into the polynomial yields a target frequency of 350Hz. At this pressure ratio, the unit's maximum operating frequency is limited to 350Hz, effectively reducing the heat generated by the motor windings and the inverter power module. This calculation method is simple and efficient, easy for the control system to call and execute in real time, and can dynamically adjust the maximum frequency limit according to changes in the unit's current pressure ratio, exhibiting good adaptability.

[0070] This implementation defines the relationship between pressure ratio and maximum frequency in a concise mathematical form by expressing the preset maximum frequency curve as a cubic polynomial. This achieves precise amplitude limiting control of compressor frequency under low pressure ratio conditions, which reduces heat generation and ensures anti-surge safety margin.

[0071] In one embodiment, such as Figure 4 As shown, controlling the heat exchange module to dissipate heat from the inverter power module and the compressor motor module includes steps S151-S153.

[0072] S151. Obtain the temperature of the compressor motor module and the inverter power module of the chiller unit; S152. If the temperature of the compressor motor module exceeds the first preset temperature range, the opening degree of the throttling element of the chiller unit shall be adjusted according to the preset adjustment logic. S153. If the temperature of the inverter power module exceeds the second preset temperature range, the opening degree of the throttling element of the chiller unit shall be adjusted according to the preset adjustment logic.

[0073] In practice, after the control system activates the heat exchange module to provide auxiliary cooling for the inverter power module and compressor motor module, the cooling effect needs to be monitored and finely controlled in real time. The control system obtains the real-time temperatures of the compressor motor module and the inverter power module through temperature sensors. The compressor motor module and the inverter power module each have different normal operating temperature ranges, namely a first preset temperature range and a second preset temperature range. The first preset temperature range is the safe operating temperature range for the compressor motor module, for example, 30℃ to 35℃; the second preset temperature range is the safe operating temperature range for the inverter power module, for example, 35℃ to 40℃.

[0074] When the system detects that the compressor motor module temperature exceeds the first preset temperature range, it indicates that the current cooling supply does not match the actual heat dissipation demand of the module. The control system adjusts the opening of the corresponding throttling element according to the preset adjustment logic, thereby adjusting the refrigerant flow to restore the module temperature to the normal range. Similarly, when the inverter power module temperature exceeds the second preset temperature range, the control system also adjusts the opening of the corresponding throttling element according to the preset adjustment logic, achieving independent temperature control of the module. Since the compressor motor module and the inverter power module correspond to different throttling elements (i.e., the first expansion valve and the second expansion valve), their cooling flow can be adjusted independently without interference, thus ensuring that their respective temperatures are within a safe range while achieving on-demand distribution of cooling refrigerant.

[0075] This implementation method independently monitors the temperature of the compressor motor module and the inverter power module, and adjusts the opening of their respective throttling elements when the temperature of either module exceeds the corresponding preset temperature range. This achieves differentiated and precise control of the cooling intensity of different heat-generating components, avoids the problem of overcooling or insufficient cooling caused by uniform liquid supply, and improves the accuracy and flexibility of heat dissipation regulation.

[0076] Furthermore, such as Figure 5 As shown, adjusting the opening degree of the throttling element of the chiller unit according to the preset adjustment logic includes steps S1531-S1534.

[0077] S1531. Compare the current temperatures of the compressor motor module and the inverter power module with the first temperature range; S1532. If the current temperature is less than the minimum boundary value of the first temperature range, then reduce the opening of the throttling element. S1533. If the current temperature is within the first temperature range, then maintain the current opening of the throttling element; S1534. If the current temperature is greater than the maximum boundary value of the first temperature range, then increase the opening degree of the throttling element.

[0078] In practice, the preset adjustment logic employs a unified temperature comparison and opening control strategy for both the compressor motor module and the inverter power module. The control system compares the current temperature of the compressor motor module or inverter power module with the corresponding preset temperature range. This preset temperature range represents the normal operating temperature range for the corresponding module, with minimum and maximum boundary values. When the current temperature is below the minimum boundary value, it indicates that the module's cooling capacity is excessive, posing a risk of overcooling. The control system reduces the opening of the corresponding throttling element, decreasing the refrigerant supply to allow the module temperature to rise back to the normal range. When the current temperature is within the preset temperature range, it indicates that the cooling capacity and heat generation are basically balanced. The control system maintains the current opening of the throttling element to maintain steady-state cooling. When the current temperature is above the maximum boundary value, it indicates that the cooling capacity is insufficient, and the module temperature has exceeded the safety limit. The control system increases the opening of the corresponding throttling element, increasing the refrigerant supply to enhance cooling, gradually reducing the module temperature back to the normal range.

[0079] The opening degree of the throttling element can be adjusted gradually. Specifically, the opening degree of the throttling element is adjusted gradually at a rate of 2% every 5 seconds until the current temperature returns to the preset temperature range. For the compressor motor module and the inverter power module, the corresponding throttling element independently executes the above adjustment logic, adjusting its opening degree based on its own current temperature and preset temperature range, thus achieving decoupled control.

[0080] This embodiment compares the current temperature of the compressor motor module and the inverter power module with the corresponding preset temperature range, and executes a unified control logic to reduce, maintain or increase the opening of the throttling element according to the comparison result. This achieves independent closed-loop adjustment of the cooling intensity of different modules. The control logic is simple and clear, the temperature response is timely, and it effectively prevents the occurrence of overcooling or overheating.

[0081] Furthermore, such as Figure 6 As shown, after adjusting the opening of the throttling element of the chiller unit, steps S1535-S1537 are also included.

[0082] S1535. Obtain the current opening degree of the throttling element; S1536. If the current opening degree of the throttling element is the maximum opening degree, and the temperature of the compressor motor module has not recovered to the first preset temperature range, then adjust the opening degree of the flow regulating valve of the chiller unit according to the preset adjustment rate until the temperature of the compressor motor module recovers to the first preset temperature range. S1537. If the current opening degree of the throttling element is the maximum opening degree, and the temperature of the inverter power module has not recovered to the second preset temperature range, then adjust the opening degree of the flow regulating valve of the chiller unit according to the preset adjustment rate until the temperature of the inverter power module recovers to the second preset temperature range.

[0083] In practice, after adjusting the opening of the throttling element according to the preset adjustment logic, the control system further acquires the current opening of the throttling element to determine whether the maximum adjustment capacity of the throttling element has been reached. When the current opening of the throttling element has reached its maximum, but the temperature of the compressor motor module or the inverter power module has not yet recovered to the corresponding preset temperature range, it indicates that simply increasing the refrigerant flow rate is insufficient to meet the cooling demand, and the subcooling capacity of the heat exchange module needs to be further enhanced. At this time, the control system gradually increases the opening of the flow regulating valve according to the preset adjustment rate, thereby increasing the flow rate of chilled water flowing through the first channel of the heat exchange module, enhancing the heat exchange with the liquid refrigerant in the second channel, increasing the subcooling of the refrigerant, and thus improving the heat absorption capacity of the refrigerant entering the liquid-cooled radiator. Specifically, the flow regulating valve can be adjusted in steps, with a preset adjustment rate of 5 steps per step, until the temperature of the corresponding module recovers to the preset temperature range.

[0084] For the compressor motor module and the inverter power module, this control logic is executed independently. When only the compressor motor module temperature has not recovered, the opening of the flow regulating valve is increased to enhance the overall subcooling effect; the same operation is performed when only the inverter power module temperature has not recovered. Since the flow regulating valve controls the total flow rate of the chilled water bypass path, its regulating effect acts on both cooling branches simultaneously. Therefore, if either module cannot meet the cooling demand even with the throttling element fully open, the overall subcooling capacity of the heat exchange module can be improved by increasing the chilled water flow rate, allowing both refrigerants to obtain higher cooling potential.

[0085] This implementation introduces the adjustment of the flow control valve as a supplementary heat dissipation method when the throttling element has been adjusted to its maximum opening but the temperature has not recovered. This forms a graded progressive control strategy that combines coarse adjustment of the throttling element with fine adjustment of the flow control valve. This ensures that the temperature of the inverter power module and compressor motor module can still be effectively controlled under complex operating conditions such as low pressure ratio and high load, thereby improving the robustness and reliability of heat dissipation control.

[0086] In summary, the method of this application obtains the current operating pressure ratio of the chiller unit, limits the compressor operating frequency according to a preset maximum frequency curve under low pressure ratio conditions to reduce heat generation from the source, and simultaneously engages the heat exchange module to subcool the liquid refrigerant to enhance heat dissipation when the cooling capacity is insufficient and frequency needs to be increased, thereby enhancing heat dissipation capacity. At the same time, by independently monitoring the temperature of the compressor motor module and the inverter power module, the opening degree of the corresponding throttling element is adjusted to achieve differentiated and precise temperature control. When the cooling demand is still not met even when the throttling element is adjusted to the maximum opening, the flow regulating valve is further introduced to improve the subcooling effect. This forms a comprehensive control strategy that combines frequency limiting to reduce heat generation with graded and progressively enhanced heat dissipation, effectively solving the problem of overheating of the inverter power module and compressor motor module under low pressure ratio and complex operating conditions, and improving the reliability and stability of air conditioning operation.

[0087] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A water chiller unit, characterized in that, include: The inverter power module is thermally coupled with a first liquid-cooled heat sink. The compressor motor module is thermally coupled with a second liquid-cooled heat sink. The evaporator has a chilled water inlet and a chilled water outlet; A condenser having a refrigerant outlet for discharging liquid refrigerant; The heat exchange module has a first flow channel and a second flow channel for mutual heat exchange. The inlet of the first flow channel is connected to the chilled water inlet, and the outlet is connected to the chilled water outlet. The inlet of the second flow channel is connected to the refrigerant outlet, and the outlet is connected to the first liquid-cooled radiator and the second liquid-cooled radiator respectively through a throttling element.

2. The chiller unit according to claim 1, characterized in that, It also includes a liquid storage module, and the condenser also has a liquid replenishment port for discharging liquid refrigerant. The inlet of the liquid storage module is connected to the liquid replenishment port, and the outlet of the liquid storage module is connected to the inlet of the second flow channel.

3. The chiller unit according to claim 2, characterized in that, It also includes a first one-way valve, which is connected in series in the flow path between the inlet of the liquid storage module and the replenishment port. The inlet of the first one-way valve is connected to the replenishment port, and the outlet of the first one-way valve is connected to the inlet of the liquid storage module.

4. The chiller unit according to claim 1, characterized in that, It also includes a second one-way valve, which is connected in series in the flow path between the refrigerant outlet and the inlet of the second flow channel. The inlet of the second one-way valve is connected to the refrigerant outlet, and the outlet of the second one-way valve is connected to the inlet of the second flow channel.

5. The chiller unit according to claim 1, characterized in that, The throttling element includes a first expansion valve and a second expansion valve. The outlet of the second flow channel is connected to the inlet of the first liquid cooler through the first expansion valve, and the outlet of the second flow channel is connected to the inlet of the second liquid cooler through the second expansion valve.

6. The chiller unit according to any one of claims 1-5, characterized in that, It also includes a solenoid valve, which is connected in series in the flow path between the inlet of the first flow channel and the chilled water inlet.

7. The chiller unit according to any one of claims 1-5, characterized in that, It also includes a filter connected in series in the flow path between the inlet of the first flow channel and the chilled water inlet.

8. The chiller unit according to any one of claims 1-5, characterized in that, It also includes a flow regulating valve, which is connected in series in the flow path between the outlet of the first flow channel and the chilled water outlet.

9. The chiller unit according to any one of claims 1-5, characterized in that, The refrigerant outlets of the first liquid-cooled radiator and the second liquid-cooled radiator are combined and connected to the inlet of the evaporator.

10. An air conditioner, characterized in that, Includes the chiller unit as described in any one of claims 1-9.

11. An air conditioning control method, characterized in that, Applied to the air conditioner of claim 10, the method includes: Obtain the current operating pressure ratio of the chiller unit; If the current operating pressure ratio is less than the preset pressure ratio threshold, then the target frequency is determined based on the current operating pressure ratio and the preset highest frequency curve; The compressor of the chiller unit is controlled to operate at the target frequency, wherein the preset maximum frequency curve is obtained by shifting the anti-surge line of the chiller unit upwards; Obtain the cooling capacity of the chiller unit; If the cooling capacity does not meet the preset conditions, the compressor of the chiller unit is controlled to increase its operating frequency according to the preset frequency increase rate, and the heat exchange module is controlled to dissipate heat from the inverter power module and the compressor motor module.

12. The method according to claim 11, characterized in that, The control of the heat exchange module to dissipate heat from the inverter power module and the compressor motor module includes: The temperature of the compressor motor module and the inverter power module of the chiller unit are obtained; If the temperature of the compressor motor module exceeds the first preset temperature range, the opening degree of the throttling element of the chiller unit is adjusted according to the preset adjustment logic; If the temperature of the inverter power module exceeds the second preset temperature range, the opening degree of the throttling element of the chiller unit is adjusted according to the preset adjustment logic.

13. The method according to claim 12, characterized in that, The step of adjusting the opening degree of the throttling element of the chiller unit according to the preset adjustment logic includes: The current temperatures of the compressor motor module and the inverter power module are compared with the first temperature range. If the current temperature is less than the minimum boundary value of the first temperature range, then reduce the opening of the throttling element; If the current temperature is within the first temperature range, then the current opening of the throttling element is maintained; If the current temperature is greater than the maximum boundary value of the first temperature range, then the opening degree of the throttling element is increased.

14. The method according to claim 12, characterized in that, After adjusting the opening of the throttling element of the chiller unit, the method further includes: Obtain the current opening degree of the throttling element; If the current opening of the throttling element is at its maximum, and the temperature of the compressor motor module has not recovered to the first preset temperature range, then the opening of the flow regulating valve of the chiller unit is adjusted according to the preset adjustment rate until the temperature of the compressor motor module recovers to the first preset temperature range. If the current opening of the throttling element is at its maximum, and the temperature of the inverter power module has not recovered to the second preset temperature range, then the opening of the chiller's flow regulating valve is adjusted according to the preset adjustment rate until the temperature of the inverter power module recovers to the second preset temperature range.

15. The method according to any one of claims 11-14, characterized in that, The expression for the preset highest frequency curve is Y=A×x 3 +B×x 2 +C×x+D, where Y is the target frequency, x is the current operating pressure ratio, and A, B, C, and D are all constants.

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