Water chiller

Abstract

The application relates to a water chiller, which comprises a compressor and a heat exchanger assembly, a motor cavity is formed in the compressor, and a motor is arranged in the motor cavity; the heat exchanger assembly comprises a condenser and an evaporator which are connected with the output end and the input end of the compressor respectively; wherein a cooling input pipeline is arranged between the motor cavity and the condenser, and a cooling output pipeline is further arranged between the motor cavity and the evaporator; an electronic expansion valve is arranged on the cooling input pipeline; part of refrigerant which is heat-exchanged in the condenser is transported into the motor cavity through the cooling input pipeline, so as to reduce the temperature in the motor cavity, and then the refrigerant is output into the evaporator through the cooling output pipeline; the water chiller does not need to introduce additional cooling liquid or gas, and the original refrigeration system is improved; the improvement cost is high, the temperature of the motor cavity can be adjusted, the controllability is high, the temperature of the motor cavity is prevented from being too high or too low, and the condensation is reduced.

Description

Technical Field

[0001] This invention belongs to the field of air conditioning equipment technology, and particularly relates to a chiller unit. Background Technology

[0002] Chillers lower temperatures through compression or heat absorption refrigeration cycles. The working principle involves a compressor compressing the refrigerant into a high-temperature, high-pressure gas, which then dissipates heat through a condenser to become a liquid. The gas is then depressurized through an expansion valve to become a low-temperature, low-pressure liquid, and finally, the evaporator absorbs heat, completing the refrigeration cycle. Chillers play a crucial role in industrial production, providing constant-temperature, constant-flow, and constant-pressure cooling water to ensure the stable operation of production equipment.

[0003] Magnetic levitation chillers are increasingly recognized by users for their advantages such as being oil-free and highly efficient. Magnetic levitation compressors control the cooling of their internal motors by controlling the temperature of the motor cavity. If the motor cavity temperature is too high, the motor may overheat, causing the internal magnetic bearings to lose magnetism or the motor to burn out. If the temperature is too low, condensation may form on the electrical components (terminals, magnetic bearing controller module, etc.) attached to the compressor body inside the compressor side cover, leading to damage to the electrical components and the unit's inability to operate. At the same time, condensation will also form on the compressor body, affecting the unit's appearance. Summary of the Invention

[0004] The purpose of this invention is to provide a chiller unit to solve the problems existing in the prior art, such as poor temperature stability in the motor cavity, difficulty in control, excessively high temperature in the motor cavity which can easily burn out working parts, and excessively low temperature which can easily cause condensation on related electrical components in the compressor side cover.

[0005] To achieve the above-mentioned objectives, the present invention employs the following technical solution: This invention proposes a chiller unit, which includes: A compressor having a motor cavity formed therein, and a motor being disposed within the motor cavity; A heat exchanger assembly comprising a condenser and an evaporator respectively connected to the output and input ends of the compressor; A cooling input pipe is provided between the motor cavity and the condenser, and a cooling output pipe is also provided between the motor cavity and the evaporator. An electronic expansion valve is provided on the cooling input pipe. After heat exchange in the condenser, part of the refrigerant is transported to the motor cavity through the cooling input pipe to reduce the temperature in the motor cavity. Then, the refrigerant is output to the evaporator through the cooling output pipe.

[0006] In some embodiments of this application, a first temperature sensor is provided inside the motor cavity to collect the temperature Tmc of the motor cavity. A second temperature sensor is also provided on the compressor for collecting the ambient temperature Ta. It further includes a controller configured to adjust the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn in the motor chamber and the target superheat degree Tssh, so that Tmc≥Ta.

[0007] In some embodiments of the present application, when Tn>Tssh, the controller controls the opening degree of the electronic expansion valve to increase; when Tn=Tssh, the controller controls the opening degree of the electronic expansion valve to remain unchanged; when Tn<Tssh, the controller controls the opening degree of the electronic expansion valve to decrease.

[0008] When the real-time superheat degree Tn in the motor chamber is greater than the target superheat degree Tssh, the opening degree of the electronic expansion valve is increased, so that more refrigerant output from the condenser is delivered to the motor chamber as a coolant to cool the motor chamber. When the real-time superheat degree Tn in the motor chamber is equal to the target superheat degree Tssh, the opening degree of the electronic expansion valve remains unchanged, and the refrigerant input into the motor chamber remains unchanged. When the real-time superheat degree Tn in the motor chamber is less than the target superheat degree Tssh, the opening degree of the electronic expansion valve is decreased, the refrigerant output from the condenser is reduced, and the temperature in the motor chamber rises, realizing the real-time adjustment of the temperature in the motor chamber.

[0009] In some embodiments of the present application, a first pressure sensor is provided in the motor chamber for collecting the motor chamber pressure Pmc, and the saturation temperature corresponding to the motor chamber pressure Pmc is T_s. A third temperature sensor is also provided on the motor for collecting the motor temperature Tm. The real-time superheat degree Tn satisfies: Tn=Tmc-T_s.

[0010] In some embodiments of the present application, after the chiller operates for a unit time, the controller compares the motor temperature Tm with a preset temperature upper limit T1: When Tm>T1, it is judged whether the current target superheat degree Tssh is the minimum target superheat degree: If so, the target superheat degree Tssh remains unchanged, and the controller adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn in the motor chamber and the target superheat degree Tssh. If not, after the controller changes the value of the target superheat degree to Tssh=Tssh-△T1, the controller adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn in the motor chamber and the changed target superheat degree Tssh.

[0011] In some embodiments of the present application, when Tm≤T1, the controller determines the difference between the motor chamber temperature Tmc and the external ambient temperature Ta: When Tmc - Ta > △t, the controller determines whether the current target superheat degree Tssh is the minimum target superheat degree: If so, the target superheat degree Tssh remains unchanged, and the controller adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn in the motor chamber and the target superheat degree Tssh; If not, after the controller changes the value of the target superheat degree to Tssh = Tssh - △t1, it adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn in the motor chamber and the changed target superheat degree Tssh.

[0012] In some embodiments of the present application, when Tmc - Ta ≤ △t, the controller compares the motor temperature Tm with the preset temperature lower limit T2, and the motor chamber temperature Tmc with the external ambient temperature Ta: When Tm < T2 and Tmc < Ta, the controller determines whether the current target superheat degree Tssh is the maximum target superheat degree: If so, the target superheat degree Tssh remains unchanged, and the controller adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn in the motor chamber and the target superheat degree Tssh; If not, after the controller changes the value of the target superheat degree to Tssh = Tssh + △t2, it adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn in the motor chamber and the changed target superheat degree Tssh.

[0013] In some embodiments of the present application, when Tm≥T2 and / or Tmc≥Ta, the controller keeps the target superheat degree Tssh unchanged, and the controller adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn in the motor chamber and the target superheat degree Tssh.

[0014] In some embodiments of the present application, the compressor includes a housing body, the motor chamber is formed within the housing body, a cooling recess is formed on the inner wall of the housing body, a cooling inner cavity is defined between the motor and the cooling recess, the inlet of the cooling inner cavity is connected to the cooling input pipeline, and the outlet of the cooling passage is connected to the cooling output pipeline.

[0015] A cooling inner cavity is formed between the cooling recess and the outer shell of the motor for the refrigerant to flow through to cool the motor.

[0016] In some embodiments of the present application, the cooling recess is arranged spirally on the inner wall of the housing body, the motor includes a stator and a rotor, the rotor is rotatably connected within the motor chamber, and the outer wall of the stator is in contact connection with the inner wall of the housing body.

[0017] The cooling recess is spiral-shaped, which can increase the contact area between the cooling cavity and the motor, thereby improving the cooling effect.

[0018] Compared with the prior art, the advantages and positive effects of the present invention are: The chiller unit involved in this application has a cooling input pipeline between the motor cavity and the condenser, and a cooling output pipeline between the motor cavity and the evaporator. An electronic expansion valve is installed on the cooling input pipeline to control the amount of coolant input into the motor cavity. During the refrigeration process of the chiller unit, the refrigerant output to the condenser undergoes heat exchange in the condenser. Part of the refrigerant is then transported as cooling liquid through the cooling input pipeline to the motor cavity to cool the motor cavity. Subsequently, the cooling liquid is output from the motor cavity to the evaporator to continue participating in the refrigeration cycle. This chiller unit does not require the introduction of additional cooling liquid or gas. Modifications to the existing refrigeration system are costly, but it allows for targeted adjustment of the motor cavity temperature, providing strong controllability and preventing the motor cavity temperature from becoming too high or too low, thus reducing condensation.

[0019] The electronic expansion valve's size is adjusted in real time based on the current actual superheat and the target superheat, resulting in high control precision. The target superheat is dynamically adjusted to a specific value, thereby changing the motor cavity temperature to automatically adapt to the ambient temperature. This ensures the motor cavity temperature is not lower than the ambient temperature, preventing condensation inside the compressor side cover from causing electrical component failure. It also prevents condensation on the outer surface of the motor housing, improving unit reliability.

[0020] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a water-cooled unit system according to an embodiment; Figure 2 This is a control logic diagram for the target superheat change according to an embodiment; Figure 3 This is a logic diagram for adjusting the opening of the electronic expansion valve according to an embodiment; Figure 4 This is one of the external structural diagrams of the compressor according to an embodiment; Figure 5 This is a second external structural diagram of the compressor according to an embodiment; Figure 6 This is a structural diagram of the internal structure of the motor cavity according to an embodiment; Figure 7 This is a diagram showing the location of the cooling recess according to an embodiment; Figure 8 This is a cross-sectional view of the outer casing of the compressor according to an embodiment; Figure 9 This is a structural diagram of a chiller unit; Figure 10 This is a structural diagram of the support component; Figure label: 10. Compressor; 101. Motor cavity; 102. Cooling recess; 11. Side cover; 12. Inlet; 13. Outlet; 14. Support leg; 15. Motor; 20. Condenser; 30. Evaporator; 40. Main expansion valve; 50. Cooling input pipe; 60. Electronic expansion valve; 70. Cooling output pipe; 80. Support base; 81. Support horizontal part; 82. Support vertical part; 83. Conformal surface; 84. Mounting hole. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and 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. Therefore, they should not be construed as limitations on this application.

[0025] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0029] In this application, the chiller unit performs the refrigeration cycle of an air conditioner by using a compressor, condenser, main expansion valve, and evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation to cool or heat an indoor space.

[0030] Low-temperature, low-pressure refrigerant enters the compressor, which compresses it into a high-temperature, high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0031] The main expansion valve expands the high-temperature, high-pressure liquid refrigerant that condenses in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant that has expanded in the main expansion valve, returning the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves its cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled.

[0032] The present invention proposes a chiller unit, which includes a compressor 10 and a heat exchanger assembly. The compressor 10 has a motor cavity 101 formed therein, and a motor 15 is disposed in the motor cavity 101.

[0033] The heat exchanger assembly includes a condenser 20 and an evaporator 30 connected to the output and input ends of the compressor 10, respectively. The compressor 10, the condenser 20 and the evaporator 30 are connected by a refrigerant pipeline. A main expansion valve 40 is provided between the condenser 20 and the evaporator 30.

[0034] A cooling input pipe 50 is provided between the motor cavity 101 and the condenser 20, and a cooling output pipe 70 is provided between the motor cavity 101 and the evaporator 30. An electronic expansion valve 60 is provided on the cooling input pipe 50. After heat exchange in the condenser 20, part of the refrigerant is transported to the motor cavity 101 through the cooling input pipe 50 to reduce the temperature in the motor cavity 101. Then, the refrigerant is output to the evaporator 30 through the cooling output pipe 70.

[0035] When the compressor 10 is working, it draws in low-temperature, low-pressure refrigerant gas and then compresses it into high-temperature, high-pressure gas.

[0036] The high-temperature, high-pressure refrigerant gas output from the compressor 10 enters the condenser 20 and releases heat to the external environment through the radiator, thus turning into a liquid.

[0037] When the refrigerant liquid passes through the main expansion valve 40, the pressure will drop rapidly, and at the same time, some of the liquid will vaporize, forming a low-temperature, low-pressure refrigerant mixture.

[0038] When a low-temperature, low-pressure refrigerant mixture enters the evaporator 30, it absorbs heat from the object being cooled, thereby achieving a cooling effect.

[0039] The refrigerant vaporizes in the evaporator 30, becoming a low-temperature, low-pressure gas, which is then drawn back into the compressor 10, completing one cycle.

[0040] From the bottom of the condenser 20, that is, part of the refrigerant after heat exchange in the condenser 20, it is introduced into the motor cavity 101 through the cooling input pipe 50 and the electronic expansion valve 60 installed thereon, to cool the motor cavity 101 so that the temperature of the motor cavity 101 is reduced to the target range.

[0041] In some embodiments of this application, a first temperature sensor is provided inside the motor cavity 101 to collect the temperature Tmc of the motor cavity 101.

[0042] The compressor 10 is also equipped with a second temperature sensor to collect the ambient temperature Ta.

[0043] Specifically, the second temperature sensor is installed inside the side cover 11 of the compressor 10 to measure the ambient temperature inside the side cover 11 of the compressor 10, which is defined as Ta.

[0044] The controller module and electrical components are placed inside the side cover 11 of the compressor 10. The control lines inside the side cover 11 of the compressor 10 and the internal components of the compressor 10 are sealed together by an airtight connector.

[0045] When the chiller unit is running, the coolant required to cool the motor cavity 101 is drawn from the bottom of the condenser 20, throttled by the electronic expansion valve 60, and then flows into the compressor 10. The internal flow channel cools the motor cavity 101, and then flows out to the evaporator 30 to participate in the refrigeration cycle.

[0046] The chiller unit also includes a controller configured to adjust the opening of the electronic expansion valve 60 according to the real-time superheat Tn and the target superheat Tssh of the motor cavity 101, so that Tmc≥Ta, thereby reducing condensation in the motor cavity 101.

[0047] In some embodiments of this application, a first pressure sensor is provided inside the motor cavity 101 to collect the pressure Pmc of the motor cavity 101, and the saturation temperature corresponding to the motor cavity pressure Pmc is T_s.

[0048] A third temperature sensor is also installed on the motor 15 to collect the motor temperature Tm.

[0049] The real-time superheat Tn satisfies: Tn = Tmc - T_s.

[0050] In other words, the electronic expansion valve 60 calculates the real-time superheat Tn (Tn = Tmc-T_s, i.e., the pressure corresponds to the saturation temperature T_s) in the motor cavity 101 by converting the temperature Tmc and the pressure Pmc in the motor cavity into saturation temperature T_s, and compares it with the target superheat Tssh to adjust the opening degree control.

[0051] Since the outlet water temperature of the evaporator 30 is constant, it indicates that the saturation temperature of the refrigerant inside the evaporator 30 is constant. The pressure Pmc inside the motor cavity 101 is equal to the sum of the resistance in the cooling output pipe 70 and the refrigerant pressure in the evaporator 30.

[0052] When the saturation temperature of the refrigerant in the evaporator 30 is constant, the pressure inside it is a fixed value. Then, an increase or decrease in the temperature Tmc of the motor chamber 101 can be understood as an increase or decrease in the real-time superheat degree Tn. The adjustment target of the real-time superheat degree Tn is the target superheat degree Tssh. Then, by comparing the real-time superheat degree with the target value, the opening degree of the expansion valve is adjusted to control the flow rate of the coolant for motor 15 cooling, and finally control to make the temperature Tmc of the motor chamber 101 ≥ Ta, automatically adapting to the change of the external environmental temperature.

[0053] Specifically, execute S22 and S23. When Tn > Tssh, the controller controls the opening degree of the electronic expansion valve 60 to increase.

[0054] When the real-time superheat degree Tn of the motor chamber 101 is greater than the target superheat degree Tssh, the opening degree of the electronic expansion valve 60 is increased, so that more refrigerant output from the condenser 20 is transported into the motor chamber 101 as the coolant to cool down the motor chamber 101.

[0055] When Tn = Tssh, execute S24 and S25, and the controller controls the opening degree of the electronic expansion valve 60 to remain unchanged.

[0056] When the real-time superheat degree Tn of the motor chamber 101 is equal to the target superheat degree Tssh, the opening degree of the electronic expansion valve 60 remains unchanged, and the refrigerant input into the motor chamber 101 remains unchanged.

[0057] When Tn < Tssh, execute S26 and S27, and the controller controls the opening degree of the electronic expansion valve 60 to decrease.

[0058] When the real-time superheat degree Tn of the motor chamber 101 is less than the target superheat degree Tssh, the opening degree of the electronic expansion valve 60 is decreased, the refrigerant output from the condenser 20 is reduced, and the temperature inside the motor chamber 101 rises, realizing the real-time adjustment of the temperature inside the motor chamber 101.

[0059] When the cold water unit is operating, the specific process of the controller controlling the temperature inside its motor chamber 101 is as follows: S11: After the cold water unit operates for a unit time, the controller compares the motor temperature Tm with the preset temperature upper limit T1: S12: When Tm > T1, judge whether the current target superheat degree Tssh is the minimum target superheat degree: S13: If so, keep the target superheat degree Tssh unchanged, and the controller adjusts the opening degree of the electronic expansion valve 60 according to the size relationship between the real-time superheat degree Tn of the motor chamber 101 and the target superheat degree Tssh.

[0060] S14: If not, after the controller changes the value of the target superheat degree to Tssh = Tssh - △T1, the controller adjusts the opening degree of the electronic expansion valve 60 according to the magnitude relationship between the real-time superheat degree Tn of the motor chamber 101 and the changed target superheat degree Tssh.

[0061] In other words, T1 is the preset temperature upper limit, that is, the highest temperature at which the motor 15 operates. When the operating temperature of the motor 15 is higher than T1, it means that in this state, the operating temperature of the motor 15 is too high. If the motor 15 operates in this state for a long time, there may be a risk of damage to the motor 15. Therefore, in this state, the electronic expansion valve 60 should be adjusted as much as possible to increase the coolant input into the motor chamber 101 to reduce the operating temperature of the motor 15.

[0062] In this state, it is necessary to reduce the target superheat degree, and then reduce the real-time superheat degree.

[0063] When the operating temperature of the motor 15 is higher than the preset temperature upper limit and it is desired to adjust the target superheat degree, it is first necessary to determine whether the target superheat degree is the minimum target superheat degree. If the target superheat degree is already the minimum superheat degree and cannot be further reduced, then, in the state where the target superheat degree is the minimum superheat degree, for the current real-time superheat degree, the opening degree of the electronic expansion valve 60 is adjusted to reduce the temperature in the motor chamber 101.

[0064] If the target superheat degree is not the minimum target superheat degree, then the controller reassigns the target superheat degree to the changed target superheat degree after reducing by △t1, defined as Tssh´, Tssh´ = Tssh - △t1.

[0065] Since the changed target superheat degree Tssh´ < Tssh, correspondingly, the real-time superheat degree also decreases, so as to achieve the purpose of reducing the temperature in the motor chamber 101.

[0066] S15: In some embodiments of the present application, when Tm ≤ T1, the controller further determines the difference between the temperature Tmc of the motor chamber 101 and the external environment temperature Ta: When Tmc - Ta > △t, it means that the difference between the temperature in the motor chamber 101 and the external environment temperature in this state is relatively high, and it is necessary to reduce the temperature in the motor chamber 101.

[0067] The specific implementation of reducing the temperature in the motor chamber 101 is achieved by adjusting the target superheat degree.

[0068] Before adjusting the target superheat degree, when executing S12, the controller needs to determine whether the current target superheat degree Tssh is the minimum target superheat degree.

[0069] If so, execute T13, keep the target superheat degree Tssh unchanged, and the controller adjusts the opening degree of the electronic expansion valve 60 according to the magnitude relationship between the real-time superheat degree Tn of the motor cavity 101 and the target superheat degree Tssh.

[0070] That is to say, at this time, the target superheat degree has reached the minimum superheat degree and cannot be further reduced. Therefore, in the state where the target superheat degree is the minimum superheat degree, for the current real-time superheat degree, adjust the opening degree of the electronic expansion valve 60 to reduce the temperature in the motor cavity 101.

[0071] If the current target superheat degree is not the minimum target superheat degree, execute T14. After the controller changes the value of the target superheat degree to Tssh = Tssh - △t1, the controller adjusts the opening degree of the electronic expansion valve 60 according to the magnitude relationship between the real-time superheat degree Tn of the motor cavity 101 and the changed target superheat degree Tssh.

[0072] In other words, the controller reassigns the target superheat degree to the changed target superheat degree after reducing it by △t1, defined as Tssh´, Tssh´ = Tssh - △t1. The changed target superheat degree Tssh´ < Tssh. The controller compares the changed target superheat degree Tssh´ with the real-time superheat degree Tn, and then adjusts the electronic expansion valve 60.

[0073] Specifically, when Tn > Tssh´, the controller controls the opening degree of the electronic expansion valve 60 to increase.

[0074] When Tn = Tssh´, the controller controls the opening degree of the electronic expansion valve 60 to remain unchanged.

[0075] When Tn < Tssh´, the controller controls the opening degree of the electronic expansion valve 60 to decrease.

[0076] When Tmc - Ta ≤ △t (that is, Tmc ≤ Ta + △t), execute T16. The controller further compares the motor temperature Tm with the preset temperature lower limit T2, and the temperature Tmc of the motor cavity 101 with the ambient temperature Ta: T2 is the preset temperature lower limit of the motor temperature. When Tm < T2, it means that the operating temperature of the motor 15 is relatively low at this time, and it is necessary to increase the operating temperature of the motor 15, that is, to increase the temperature of the motor cavity 101.

[0077] When Tmc < Ta, it means that the temperature of the motor cavity 101 is lower than the ambient temperature. The controller also needs to increase the temperature of the motor cavity 101 to prevent condensation.

[0078] Under the above two conditions, it is necessary to increase the temperature of the motor cavity 101, that is, to increase the target superheat degree.

[0079] Similarly, before increasing the target superheat degree, when performing S17, it is also necessary to first determine whether the current target superheat degree Tssh is the maximum target superheat degree: Specifically, when Tm < T2 and Tmc < Ta, and when the current target superheat degree is the maximum target superheat degree, perform T13. The controller keeps the target superheat degree Tssh unchanged, and the controller adjusts the opening degree of the electronic expansion valve 60 according to the size relationship between the real-time superheat degree Tn of the motor chamber 101 and the target superheat degree Tssh.

[0080] If the current target superheat degree is not the maximum target superheat degree, then perform S18. After the controller changes the value of the target superheat degree to Tssh = Tssh + Δt2, the controller adjusts the opening degree of the electronic expansion valve 60 according to the size relationship between the real-time superheat degree Tn of the motor chamber 101 and the changed target superheat degree Tssh.

[0081] In some embodiments of the present application, when Tm ≥ T2 and / or Tmc ≥ Ta, the controller keeps the target superheat degree Tssh unchanged, and the controller adjusts the opening degree of the electronic expansion valve 60 according to the size relationship between the real-time superheat degree Tn of the motor chamber 101 and the target superheat degree Tssh.

[0082] That is, when at least one of the conditions of Tm ≥ T2 and Tmc ≥ Ta is satisfied, it indicates that the temperature of the motor 15 is greater than the preset minimum temperature, meeting the temperature condition for the operation of the motor 15. Or, the temperature of the motor chamber 101 is not less than the external ambient temperature, and condensation will not occur on the surface of the motor chamber 101 and the housing of the motor 15. There is no need to increase the target superheat degree. Therefore, the controller keeps the existing target superheat degree unchanged, and adjusts the opening degree of the electronic expansion valve 60 according to the size relationship between the real-time superheat degree Tn of the motor chamber 101 and the target superheat degree Tssh, and the temperature of the motor chamber 101 can be stabilized within the preset range.

[0083] Next, a specific cooling flow path in the motor chamber 101 of the compressor 10 will be described: The compressor 10 includes a housing. The motor chamber 101 is formed within the housing. A cooling recess 102 is formed on the inner wall of the housing. A cooling inner cavity is defined between the motor 15 and the cooling recess 102. The inlet 12 of the cooling inner cavity is connected to the cooling input pipeline 50, and the outlet 13 of the cooling path is connected to the cooling output pipeline 70.

[0084] In some embodiments, the cooling recess 102 may be an integral structure formed on the inner wall of the housing and extending along the length direction of the housing. The motor 15 includes a stator and a rotor. The rotor is rotatably connected within the motor chamber 101, and the outer wall of the stator is in contact connection with the inner wall of the housing. Then, a cylindrical cooling inner cavity is formed between the motor 15 and the inner wall of the housing.

[0085] The cooling input pipe 50 and the cooling output pipe 70 are connected to the inlet 12 and outlet 13 of the cooling cavity, respectively. The refrigerant, which serves as the coolant, enters the cooling cavity from the cooling input pipe 50, cools the motor 15, and then enters the evaporator 30 through the cooling output pipe 70 to participate in the refrigeration cycle of the refrigeration unit.

[0086] In some embodiments of this application, the cooling recess 102 is arranged in a spiral shape on the inner wall of the housing, the motor 15 includes a stator and a rotor, the rotor is rotatably connected in the motor cavity 101, and the outer wall of the stator is in contact with the inner wall of the housing.

[0087] The inlet 12 and outlet 13 of the cooling cavity are located at the two ends of the spiral cooling recess 102, respectively. The refrigerant, which is the coolant, enters the cooling cavity from one end of the spiral cooling channel. After cooling the motor 15 along the spiral cooling channel, it is output to the evaporator 30 through the cooling output pipe 70 to participate in the refrigeration cycle of the water-cooled unit.

[0088] The advantages and positive effects of this invention are: The chiller unit involved in this application has a cooling input pipe 50 between the motor cavity 101 and the condenser 20, and a cooling output pipe 70 between the motor cavity 101 and the evaporator 30. An electronic expansion valve 60 is provided on the cooling input pipe 50 to control the amount of coolant input into the motor cavity 101. During the refrigeration process of the chiller unit, the refrigerant output to the condenser 20 undergoes heat exchange in the condenser 20. Part of the refrigerant is then transported as cooling liquid through the cooling input pipe 50 to the motor cavity 101 to cool the motor cavity 101. Subsequently, the cooling liquid is output from the motor cavity 101 to the evaporator 30 to continue participating in the refrigeration cycle.

[0089] This chiller unit does not require the introduction of additional cooling liquid or gas. Modifications to the existing refrigeration system are costly. However, it allows for targeted temperature adjustment of the motor cavity 101, providing strong controllability and preventing the motor cavity 101 temperature from becoming too high or too low, thus reducing condensation.

[0090] The electronic expansion valve 60 is adjusted in real time based on the current actual superheat and the target superheat, resulting in high control precision. The target superheat is dynamically adjusted to a specific value, thereby changing the temperature of the motor cavity 101. This allows the temperature of the motor cavity 101 to automatically adapt to the ambient temperature, ensuring that the temperature of the motor cavity 101 is not lower than the ambient temperature. This prevents condensation inside the compressor 10 side cover from causing electrical component failure, increases the service life of the working parts inside the compressor 10, and simultaneously prevents condensation from forming on the outer surface of the motor 15 housing, improving the reliability of the unit.

[0091] refer to Figure 9 , Figure 10 In some embodiments of this application, the compressor 10 is fixed to the outer wall of the evaporator 30 and / or the condenser 20 by a support base 80. In order to improve the support strength of the support base 80 and disperse the pressure of the compressor 10 acting on the condenser 20 or the evaporator 30, at least two support bases 80 are provided at intervals along the axial direction of the evaporator 30 or the condenser 20.

[0092] The support base 80 includes two support uprights 82 spaced apart and a support horizontal part 81 located between the two support uprights 82. The bottom of the compressor 10 is provided with a support leg 14. The support horizontal part 81 is provided with a mounting hole 84. The support leg 14 is detachably connected to the support horizontal part 81 through the mounting hole 84.

[0093] The support leg 14 and the mounting hole 84 are connected and fixed by fasteners, specifically fastening bolts. Washers and spring washers are also provided between the fasteners and the connecting seat to increase the stability of the connection.

[0094] The bottom of the support stand 82 has a conformal surface 83 that is adapted to the outer wall of the evaporator 30, and the support base 80 is welded to the outer wall of the evaporator 30 through the conformal surface 83.

[0095] Under the action of the conformal surface 83, the support base 80 distributes the weight of the compressor 10 onto the side wall of the evaporator 30, which helps to improve the support strength.

[0096] The two supporting uprights 82 and the supporting horizontals 81 can be integrally formed from sheet metal.

[0097] Alternatively, the support upright 82 and the support horizontal 81 can be processed separately and then fixedly connected by welding or mechanical connection.

[0098] The conformal surface 83 is formed at the bottom of the support stand 82 and is directly connected to the outer wall of the evaporator 30.

[0099] In some embodiments of this application, the compressor 10 will also vibrate during operation. In order to reduce vibration transmission, a vibration damping part is provided between the connecting seat and the support seat 80.

[0100] The vibration damping part is made of rubber and has through holes for fasteners to pass through.

[0101] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0102] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included 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, Comprising: A compressor, within which a motor chamber is formed, and a motor is disposed in the motor chamber; A heat exchanger assembly, which includes a condenser and an evaporator respectively connected to the output end and the input end of the compressor; Wherein, a cooling input pipeline is provided between the motor chamber and the condenser, and a cooling output pipeline is also provided between the motor chamber and the evaporator; an electronic expansion valve is provided on the cooling input pipeline; a part of the refrigerant after heat exchange in the condenser is transported to the motor chamber through the cooling input pipeline to reduce the temperature in the motor chamber, and then the refrigerant is output to the evaporator through the cooling output pipeline.

2. The water chiller according to claim 1, wherein A first temperature sensor is disposed in the motor chamber for collecting the motor chamber temperature Tmc; A second temperature sensor is disposed on the compressor for collecting the ambient temperature Ta; It further includes a controller, which is configured to adjust the opening degree of the electronic expansion valve according to the magnitude of the real-time superheat degree Tn of the motor chamber and the target superheat degree Tssh, so that Tmc≥Ta.

3. The water chiller according to claim 2, wherein When Tn>Tssh, the controller controls the opening degree of the electronic expansion valve to increase; when Tn=Tssh, the controller controls the opening degree of the electronic expansion valve to remain unchanged; When Tn<Tssh, the controller controls the opening degree of the electronic expansion valve to decrease.

4. The water chiller according to claim 2, wherein A first pressure sensor is disposed in the motor chamber for collecting the motor chamber pressure Pmc, and the saturation temperature corresponding to the motor chamber pressure Pmc is T_s; A third temperature sensor is further disposed on the motor for collecting the motor temperature Tm; The real-time superheat degree Tn satisfies: Tn=Tmc-T_s.

5. The water chiller according to claim 3, wherein After the water chiller operates for a unit time, the controller compares the motor temperature Tm with a preset temperature upper limit T1: When Tm>T1, it is judged whether the current target superheat degree Tssh is the minimum target superheat degree: If so, the target superheat degree Tssh remains unchanged, and the controller adjusts the opening degree of the electronic expansion valve according to the magnitude of the real-time superheat degree Tn of the motor chamber and the target superheat degree Tssh; If not, the controller changes the value of the target superheat degree to Tssh=Tssh-△T1, and then adjusts the opening degree of the electronic expansion valve according to the magnitude of the real-time superheat degree Tn of the motor chamber and the changed target superheat degree Tssh.

6. The water chiller according to claim 5, wherein When Tm≤T1, the controller judges the difference between the motor chamber temperature Tmc and the ambient temperature Ta: When Tmc-Ta>△t, the controller judges whether the current target superheat degree Tssh is the minimum target superheat degree: If so, the target superheat degree Tssh remains unchanged, and the controller adjusts the opening degree of the electronic expansion valve according to the magnitude of the real-time superheat degree Tn of the motor chamber and the target superheat degree Tssh; If not, after the controller changes the value of the target superheat degree to Tssh = Tssh - △t1, it adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn of the motor chamber and the changed target superheat degree Tssh.

7. The water chiller according to claim 6, wherein When Tmc - Ta ≤ △t, the controller compares the motor temperature Tm with the preset temperature lower limit T2, and the motor chamber temperature Tmc with the external ambient temperature Ta: When Tm < T2 and Tmc < Ta, the controller determines whether the current target superheat degree Tssh is the maximum target superheat degree: If so, the target superheat degree Tssh remains unchanged, and the controller adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn of the motor chamber and the target superheat degree Tssh; If not, after the controller changes the value of the target superheat degree to Tssh = Tssh + △t2, the controller adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn of the motor chamber and the changed target superheat degree Tssh.

8. The water chiller according to claim 7, wherein When Tm ≥ T2 and / or Tmc ≥ Ta, the controller keeps the target superheat degree Tssh unchanged, and the controller adjusts the opening degree of the electronic expansion valve according to the magnitude relationship between the real-time superheat degree Tn of the motor chamber and the target superheat degree Tssh.

9. The water chiller according to claim 1, wherein The compressor includes an outer housing, the motor chamber is formed within the outer housing, a cooling recess is formed on the inner wall of the outer housing, a cooling inner cavity is defined between the motor and the cooling recess, an inlet of the cooling inner cavity is connected to the cooling input pipeline, and an outlet of the cooling passage is connected to the cooling output pipeline.

10. The water chiller according to claim 9, wherein The cooling recess is arranged along a spiral shape on the inner wall of the outer housing, the motor includes a stator and a rotor, the rotor is rotatably connected within the motor chamber, and an outer wall of the stator is in contact connection with the inner wall of the outer housing.

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