Refrigeration system and its control method

Abstract

This disclosure relates to a refrigeration system and its control method, wherein the refrigeration system includes: a compressor (1) including an intake port (11) and an exhaust port (12); a condenser (2) having a first heat exchange chamber (21) and a second heat exchange chamber (5), the exhaust port (12) being connected to the first heat exchange chamber (21), the second heat exchange chamber (5) being connected to the intake port (11), and the second heat exchange chamber (5) being disposed within the first heat exchange chamber (21) and configured to be connected to the first heat exchange chamber (21). 21) The refrigerant heat exchanger inside; evaporator (4); first pipe (31) connected between condenser (2) and second heat exchange chamber (5), and evaporator (4) is provided on the first pipe (31); second pipe (32) connected between condenser (2) and second heat exchange chamber (5), and second pipe (32) bypasses evaporator (4); and throttling assembly (3) for throttling the refrigerant passing through the first pipe (31) and the second pipe (32).

Description

Technical Field

[0001] This disclosure relates to the field of refrigeration system technology, and in particular to a refrigeration system and its control method. Background Technology

[0002] A refrigeration system mainly consists of a compressor, condenser, throttling mechanism, and evaporator. Its operation involves four processes: compression, condensation, throttling, and evaporation, which repeat continuously to achieve continuous cooling. Improving the efficiency and controlling the refrigeration system are always important considerations.

[0003] Increasing the subcooling of a refrigeration system benefits both its capacity and energy efficiency; therefore, improving subcooling has always been a key focus for enhancing the energy efficiency of refrigeration systems. Additionally, appropriately increasing the suction superheat can also increase the reliability of the refrigeration system and prevent liquid slugging during compression, which could damage the system. Summary of the Invention

[0004] The embodiments of this disclosure provide a refrigeration system and its control method, which can reduce the outlet liquid temperature of the condenser.

[0005] According to one aspect of this disclosure, a refrigeration system is provided, comprising:

[0006] The compressor includes an intake port and an exhaust port;

[0007] A condenser has a first heat exchange chamber and a second heat exchange chamber, an exhaust port connected to the first heat exchange chamber, and a second heat exchange chamber connected to the intake port. The second heat exchange chamber is located inside the first heat exchange chamber and is configured to exchange heat with the refrigerant inside the first heat exchange chamber.

[0008] Evaporator;

[0009] The first pipeline connects the condenser and the second heat exchange chamber, and an evaporator is provided on the first pipeline;

[0010] The second pipe connects the condenser and the second heat exchange chamber, and bypasses the evaporator; and

[0011] A throttling component is used to throttle the refrigerant flowing through the first and second pipes.

[0012] In some embodiments, the second heat exchange chamber is located in the middle and lower regions of the first heat exchange chamber.

[0013] In some embodiments, the condenser includes a first heat exchange tube, which is disposed in a first heat exchange chamber and a cooling medium flows through the first heat exchange tube, and a second heat exchange chamber is disposed at a distance from the first heat exchange tube.

[0014] In some embodiments, the second heat exchange chamber includes a second heat exchange tube, wherein the refrigerant in the second heat exchange tube exchanges heat with the refrigerant in the first heat exchange chamber in a countercurrent manner.

[0015] In some embodiments, the throttling assembly includes a first throttling element and a second throttling element. The first throttling element is located in a first pipeline and is disposed between the outlet of the condenser and the inlet of the evaporator. The first pipeline has a node downstream of the outlet of the evaporator that connects to the second pipeline. The second throttling element is located in the second pipeline and is disposed between the outlet of the condenser and the node.

[0016] In some embodiments, the regulation of the first pipeline by the first throttling element and the regulation of the second pipeline by the second throttling element are independent of each other.

[0017] In some embodiments, the throttling assembly includes a first throttling element, and a first pipeline and a second pipeline have a common pipeline between the outlet of the condenser and the inlet of the evaporator, with the first throttling element disposed on the common pipeline.

[0018] In some embodiments, the throttling assembly further includes a second throttling element, wherein the first pipeline has a node connected to the second pipeline downstream of the evaporator outlet, the second throttling element is located in the second pipeline and is disposed between the condenser outlet and the node, and the second throttling element is located on a length segment outside the common pipeline.

[0019] In some embodiments, the first pipeline has a node connected to the second pipeline downstream of the evaporator outlet, and the refrigeration system further includes:

[0020] A first temperature sensor, located on the pipe between the node and the evaporator outlet, is configured to detect a first temperature of the refrigerant in order to adjust the opening of the throttling assembly.

[0021] In some embodiments, the refrigeration system further includes:

[0022] The second temperature sensor, located on the pipeline between the second heat exchange chamber and the intake port, is configured to detect the second temperature of the refrigerant in order to adjust the opening of the throttling assembly.

[0023] In some embodiments, the throttling assembly includes a first throttling element located in a first pipeline and disposed between the outlet of the condenser and the inlet of the evaporator. The first pipeline has a node downstream of the outlet of the evaporator that connects to a second pipeline. The refrigeration system further includes:

[0024] A first temperature sensor, located on the pipe between the node and the evaporator outlet, is configured to detect a first temperature of the refrigerant in order to adjust the opening of the first throttling element.

[0025] In some embodiments, the throttling assembly further includes a second throttling element located in the second pipeline and disposed between the outlet of the condenser and the node, and the refrigeration system further includes:

[0026] The second temperature sensor, located between the second heat exchange chamber and the air intake, is configured to detect the second temperature of the refrigerant in order to adjust the opening of the second throttling element.

[0027] According to another aspect of this disclosure, a control method for a refrigeration system based on the above embodiments is proposed, comprising:

[0028] Calculate the first difference between the first temperature and the evaporation temperature of the evaporator;

[0029] Compare the first difference with the first preset range:

[0030] If the first difference is greater than the maximum value of the first preset range, the opening degree of the first throttling element is increased;

[0031] If the first difference is less than the minimum value of the first preset range, the opening of the first throttling element is reduced;

[0032] When the first difference is within the first preset range, the opening of the first throttling element is kept unchanged.

[0033] In some embodiments, the throttling assembly further includes a second throttling element located in the second pipeline and disposed between the outlet of the condenser and the node; the refrigeration system further includes a second temperature sensor disposed in the pipeline between the second heat exchange chamber and the suction port; the second temperature sensor is configured to detect a second temperature of the refrigerant; and the control method further includes:

[0034] Calculate the second difference between the second temperature and the evaporation temperature;

[0035] Compare the second difference with the second preset range:

[0036] If the second difference is greater than the maximum value of the second preset range, the opening of the second throttling element is reduced;

[0037] If the second difference is less than the minimum value of the second preset range, the opening degree of the second throttling element is increased;

[0038] When the second difference is within the second preset range, the opening of the second throttling element is kept constant.

[0039] Based on the above technical solution, the refrigeration system of this embodiment exchanges heat between the refrigerant in the second heat exchange chamber and the first heat exchange chamber, enabling the low-temperature suction pipe to exchange heat with the high-temperature refrigerant in the condenser, thereby reducing the temperature of the refrigerant in the condenser, increasing the subcooling of the refrigeration system, and achieving energy efficiency improvement. At the same time, by increasing the suction superheat of the refrigerant in the suction pipe through heat exchange, liquid slugging in the compressor can be prevented. By adding a second pipeline, the second heat exchange chamber can be utilized efficiently, achieving better refrigerant distribution and accurately reducing and controlling the liquid outlet temperature of the condenser. Attached Figure Description

[0040] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this application, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings:

[0041] Figure 1 This is a schematic diagram illustrating the principle of some embodiments of the refrigeration system disclosed herein.

[0042] Figure 2 This is a schematic diagram of some other embodiments of the refrigeration system disclosed herein.

[0043] Figure 3 This is a schematic diagram of some further embodiments of the refrigeration system disclosed herein.

[0044] Explanation of reference numerals in the attached figures

[0045] 1. Compressor; 2. Condenser; 3. Throttling assembly; 4. Evaporator; 5. Second heat exchange chamber; 6. First temperature sensor; 7. Second temperature sensor; 11. Inlet; 12. Outlet; 21. First heat exchange chamber; 31. First pipeline; 32. Second pipeline; 301. First throttling element; 302. Second throttling element; O. Node. Detailed Implementation

[0046] The present disclosure is described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. The aspects so defined may be combined with any other aspect or aspects unless expressly stated otherwise. In particular, any feature considered preferred or advantageous may be combined with one or more other features considered preferred or advantageous.

[0047] The terms "first" and "second" used in this disclosure are merely for ease of description and to distinguish different components with the same name, and do not indicate a sequential or primary / secondary relationship.

[0048] In the description of this disclosure, it should be understood that the terms “inner,” “outer,” “upper,” and “lower,” etc., which indicate orientation or positional relationship based on the condenser, heat exchange chamber, or heat exchange tube, are defined only for the convenience of describing this disclosure and are not intended to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this disclosure.

[0049] First, this disclosure proposes a refrigeration system, such as Figures 1 to 3 As shown, it includes:

[0050] Compressor 1 includes an intake port 11 and an exhaust port 12;

[0051] The condenser 2 has a first heat exchange chamber 21 and a second heat exchange chamber 5. The exhaust port 12 is connected to the first heat exchange chamber 21, and the second heat exchange chamber 5 is connected to the intake port 11. The second heat exchange chamber 5 is disposed in the first heat exchange chamber 21 and is configured to exchange heat with the refrigerant in the first heat exchange chamber 21.

[0052] Evaporator 4;

[0053] The first pipe 31 is connected between the condenser 2 and the second heat exchange chamber 5, and the first pipe 31 is equipped with an evaporator 4;

[0054] The second pipe 32 connects the condenser 2 and the second heat exchange chamber 5, and the second pipe 32 bypasses the evaporator 4; and

[0055] Throttling component 3 is used to throttle the refrigerant passing through the first pipe 31 and the second pipe 32.

[0056] Specifically, in the refrigeration cycle, the gaseous refrigerant entering the second heat exchange chamber 5 exchanges heat with the circulating cooling medium, changing from a gaseous state to a liquid state and flowing out of the condenser. This refrigerant is also referred to as the cooling medium. Specifically, the compressor 1 has only one suction port 11, which improves its compression efficiency. The compressor 1 is a precision component, and given the possibility of minimizing the number of openings, using a single port 11 provides the best compression effect. Specifically, the refrigerant flow rate in the first pipe 31 is greater than the refrigerant flow rate in the second pipe 32.

[0057] Specifically, by changing the direction of the suction pipe of the compressor 1, the refrigeration system allows the suction pipe to pass through the first heat exchange chamber 21 of the condenser 2. By adding a second heat exchange chamber 5 to the suction pipe inside the condenser 2, the refrigerant in the second heat exchange chamber 5 can exchange heat with the refrigerant in the first heat exchange chamber 21, thereby reducing the liquid outlet temperature of the condenser and reducing the subcooling of the refrigeration system. At the same time, it can also increase the temperature of the refrigerant in the second heat exchange chamber 5 and increase the suction superheat.

[0058] Specifically, the second pipe 32 is directly connected between the condenser 2 and the second heat exchange chamber 5, meaning the second pipe 32 does not pass through the evaporator 4. Specifically, the refrigerant entering the second heat exchange chamber 5 from the first pipe 31 is a low-temperature gaseous refrigerant. This low-temperature gaseous refrigerant exchanges heat with the refrigerant in the first heat exchange chamber 21, reducing the outlet liquid temperature of the condenser 2. Specifically, the refrigerant entering the second heat exchange chamber 5 from the second pipe 32 is a cooled and depressurized liquid refrigerant after being throttled by the throttling component 3. The increase in auxiliary refrigerant can accurately reduce and control the outlet liquid temperature of the condenser 2, allowing the refrigeration system to achieve better adaptation.

[0059] Optionally, the refrigeration system can be a water chiller, etc. For example, the liquid refrigerant in the second pipeline 32 is throttled and cooled and depressurized by the throttling component 3 and flows into the second heat exchange chamber 5 for evaporation and heat absorption, so that the refrigerant in the first heat exchange chamber 21 of the condenser 2 is cooled down, and the cooler refrigerant flows into the evaporator 4 for heat exchange of the water chiller.

[0060] Optionally, flow control of the second pipe 32 can be achieved by changing the pipe diameter, or by installing a second throttling element on the second pipe 32. Optionally, the first pipe 31 and the second pipe 32 may or may not have a common pipe between the outlet of the condenser 2 and the inlet of the evaporator 4. For example, in the absence of a common pipe, a suction port and a second opening may be provided in the bottom region of the condenser 2, with the suction port connected to the first pipe 31 and the second opening connected to the second pipe 32. Optionally, the throttling assembly 3 may include only the first throttling element 301 provided on the common pipe, or it may include both the first throttling element 301 and the second throttling element 302.

[0061] The refrigeration system of this embodiment has a simple structure and high reliability. By exchanging heat between the refrigerant in the second heat exchange chamber and the first heat exchange chamber, the low-temperature suction pipe can exchange heat with the high-temperature refrigerant in the condenser, thereby reducing the temperature of the refrigerant in the condenser, increasing the subcooling of the refrigeration system, and improving the energy efficiency of the refrigeration system. At the same time, by increasing the suction superheat of the refrigerant in the suction pipe through heat exchange, liquid slugging in the compressor can be prevented. By adding a second pipeline, the second heat exchange chamber can be used efficiently, achieving better refrigerant distribution and accurately reducing and controlling the liquid outlet temperature of the condenser.

[0062] In some embodiments, such as Figures 1 to 3 As shown, the second heat exchange chamber 5 is located in the middle and lower region of the first heat exchange chamber 21. Specifically, the refrigerant in the middle and lower region of the first heat exchange chamber 21 is a gas-liquid mixture after heat exchange with the cooling medium.

[0063] In this embodiment, the gaseous refrigerant entering the first heat exchange chamber first exchanges heat with the circulating cooling medium, transforming into a gas-liquid mixture, and then exchanges heat with the refrigerant in the second heat exchange chamber, further reducing the refrigerant temperature. This can effectively reduce the liquid outlet temperature of the condenser, thereby improving the energy efficiency of the refrigeration system.

[0064] In some embodiments, the condenser 2 includes a first heat exchange tube disposed within a first heat exchange chamber 21, and a cooling medium flows through the first heat exchange tube. A second heat exchange chamber 5 is disposed spaced apart from the first heat exchange tube. Optionally, the cooling medium may be cooling water or the like.

[0065] This embodiment, by setting the second heat exchange chamber and the first heat exchange tube separately, can avoid heat exchange between the refrigerant and the cooling medium in the second heat exchange chamber, thereby optimizing the heat exchange effect, further reducing the liquid outlet temperature of the condenser, increasing the subcooling of the refrigeration system, and further increasing the suction superheat, preventing liquid slugging during the compression process.

[0066] In some embodiments, the second heat exchange chamber 5 includes a second heat exchange tube, and the refrigerant in the second heat exchange tube exchanges heat with the refrigerant in the first heat exchange chamber 21 in a countercurrent manner.

[0067] This embodiment achieves countercurrent heat exchange between the refrigerant in the second heat exchange tube and the refrigerant in the first heat exchange chamber, resulting in heat exchange between the two refrigerants at different temperatures, a larger temperature difference, and optimized heat exchange effect.

[0068] In some embodiments, such as Figure 1 and Figure 3 As shown, the throttling assembly 3 includes a first throttling element 301 and a second throttling element 302. The first throttling element 301 is located in the first pipeline 31 and is disposed between the outlet of the condenser 2 and the inlet of the evaporator 4. The first pipeline 31 has a node O downstream of the outlet of the evaporator 4 that connects to the second pipeline 32. The second throttling element 302 is located in the second pipeline 32 and is disposed between the outlet of the condenser 2 and the node O.

[0069] Specifically, the circulation of the refrigeration system through the first pipeline 31 can be called the main pipeline. The refrigerant discharged from the exhaust port 12 of the compressor 1 enters the first heat exchange chamber 21 of the condenser 2. The liquid refrigerant after being condensed by the condenser 2 enters the evaporator 4 after being throttled by the first throttling device 301. After evaporating in the evaporator 4, it flows into the second heat exchange chamber 5 and finally returns to the suction port 11 of the compressor 1.

[0070] Specifically, the circulation of the refrigeration system through the second pipeline 32 can be called the auxiliary pipeline. The refrigerant discharged from the exhaust port 12 of the compressor 1 enters the first heat exchange chamber 21 of the condenser 2. The liquid refrigerant after being condensed by the condenser 2 flows directly into the second heat exchange chamber 5 after being throttled by the second throttling device 302, and finally returns to the suction port 11 of the compressor 1.

[0071] This embodiment, by setting two throttling devices, can perform precise dual throttling control of the refrigeration system, which can improve the heat exchange distribution accuracy of the refrigerant. Through the throttling of the second pipeline, more refrigerant can flow into the second heat exchange chamber to evaporate and absorb heat without liquid slugging, which can significantly reduce the condensation temperature and improve the energy efficiency of the refrigeration system.

[0072] In some embodiments, such as Figure 1 As shown, the adjustment of the first throttling device 301 on the first pipeline 31 and the adjustment of the second throttling device 302 on the second pipeline 32 are independent of each other.

[0073] This embodiment allows the adjustment of the first pipeline by the first throttling element to be independent of the adjustment of the second pipeline by the second throttling element. This avoids the opening size of the first throttling element on the first pipeline affecting the refrigerant flow rate on the second pipeline, thus improving the flexibility of the throttling component control.

[0074] In some embodiments, such as Figure 2 and Figure 3 As shown, the throttling assembly 3 includes a first throttling element 301, and a first pipe 31 and a second pipe 32 have a common pipe between the outlet of the condenser 2 and the inlet of the evaporator 4. The first throttling element 301 is disposed on the common pipe.

[0075] Optionally, if the first throttling device 301 is located in the common pipeline, the flow rate of the second pipeline 32, excluding the common pipeline, can be adjusted by adjusting the pipe diameter, by setting a flow control valve, or by setting other throttling devices.

[0076] This embodiment reduces the number of throttling devices by placing the first throttling device on the common pipeline of the first and second pipelines, thereby improving the energy efficiency and reliability of the refrigeration system while reducing the production cost of the refrigeration system.

[0077] In some embodiments, such as Figure 3 As shown, the throttling assembly 3 also includes a second throttling element 302. The first pipeline 31 has a node O connected to the second pipeline 32 downstream of the outlet of the evaporator 4. The second throttling element 302 is located in the second pipeline 32 and is located between the outlet of the condenser 2 and the node O. The second throttling element 302 is located on a length section outside the common pipeline.

[0078] This embodiment enables precise dual-throttling control of the refrigeration system by placing the second throttling element on a length segment outside the common pipeline, thereby improving the heat exchange distribution accuracy of the refrigerant and enhancing the energy efficiency of the refrigeration system.

[0079] In some embodiments, such as Figures 1 to 3 As shown, the first pipe 31 has a node O downstream of the outlet of the evaporator 4 that connects to the second pipe 32. The refrigeration system also includes:

[0080] The first temperature sensor 6, located on the pipe between node O and the outlet of evaporator 4, is configured to detect the first temperature of the refrigerant in order to adjust the opening of the throttling assembly 3.

[0081] Specifically, the opening degree of the throttling component 3 is adjusted according to the difference between the first temperature of the refrigerant and the evaporation temperature. For example, the first temperature can be T1, and the evaporation temperature of the evaporator can be T3. When T1-T3>a+b% (a and b are set values), the opening degree of the throttling component 3 is adjusted to increase the amount of refrigerant entering the evaporator 4; when T1-T3<a+b% (a and b are set values), the opening degree of the throttling component 3 is adjusted to decrease the amount of refrigerant entering the evaporator 4; when ab%≤T1-T3≤a+b% (a and b are set values), there is no need to adjust the opening degree of the throttling component 3.

[0082] Specifically, 'a' and 'b' are empirical values ​​used to adjust the stability of the system. Values ​​that are too large or too small are not good. 'a' is called suction superheat, and 'b' is called suction superheat deviation (this deviation is an empirical value that serves as a calibration). If 'a' is too large, there will be too little refrigerant in the evaporator, affecting heat exchange. If the value of 'a' is too small, there will be too much refrigerant in the evaporator, which may flow into the compressor and cause liquid slugging.

[0083] This embodiment detects the first temperature of the refrigerant to adjust the opening of the throttling component, thereby enabling reasonable control of the refrigerant flow in the evaporator and preventing the evaporator from being affected by insufficient refrigerant flow, thus ensuring that the cooling capacity is not affected.

[0084] In some embodiments, such as Figures 1 to 3 As shown, the refrigeration system also includes:

[0085] The second temperature sensor 7, located on the pipeline between the second heat exchange chamber 5 and the air intake 11, is configured to detect the second temperature of the refrigerant in order to adjust the opening of the throttling assembly 3.

[0086] Specifically, the opening of the throttling component 3 is adjusted according to the difference between the second temperature of the refrigerant and the evaporation temperature. For example, the second temperature can be T2, and the evaporation temperature of the evaporator can be T3. When T2-T3>c+d% (c and d are set values), the opening of the throttling component 3 is adjusted to reduce the amount of refrigerant entering the second heat exchange chamber 5; when T2-T3<c+d% (c and d are set values), the opening of the throttling component 3 is adjusted to increase the amount of refrigerant entering the second heat exchange chamber 5; when cd%≤T2-T3≤c+d% (c and d are set values), there is no need to adjust the opening of the throttling component 3.

[0087] This embodiment detects the second temperature of the refrigerant to adjust the opening of the throttling component, thereby enabling reasonable control of the refrigerant flow in the second heat exchange chamber. This prevents the compressor from liquid slugging due to excessive refrigerant flow into the second heat exchange chamber. Furthermore, by throttling the second pipeline, more refrigerant can flow into the second heat exchange chamber to evaporate and absorb heat without liquid slugging, significantly reducing the condensing temperature and improving the energy efficiency of the refrigeration system.

[0088] In some embodiments, such as Figures 1 to 3 As shown, the throttling assembly 3 includes a first throttling element 301, which is located in the first pipe 31 and positioned between the outlet of the condenser 2 and the inlet of the evaporator 4. The first pipe 31 has a node O downstream of the outlet of the evaporator 4 that connects to the second pipe 32. The refrigeration system also includes:

[0089] The first temperature sensor 6, located on the pipe between node O and the outlet of evaporator 4, is configured to detect the first temperature of the refrigerant in order to adjust the opening of the first throttling element 301.

[0090] Specifically, the opening of the throttling component 3 is adjusted according to the difference between the first temperature of the refrigerant and the evaporation temperature. For example, the first temperature can be T1, and the evaporation temperature of the evaporator can be T3. When T1-T3>a+b% (a and b are set values), the opening of the first throttling component 301 is increased to increase the amount of refrigerant entering the evaporator 4; when T1-T3<a+b% (a and b are set values), the opening of the first throttling component 301 is decreased to decrease the amount of refrigerant entering the evaporator 4; when ab%≤T1-T3≤a+b% (a and b are set values), there is no need to adjust the opening of the first throttling component 301.

[0091] This embodiment detects the first temperature of the refrigerant to adjust the opening of the first throttling element, thereby enabling reasonable control of the refrigerant flow in the evaporator and preventing the evaporator from being affected by insufficient refrigerant flow, thus ensuring that the cooling capacity is not affected.

[0092] In some embodiments, such as Figures 1 to 3 As shown, the throttling assembly 3 also includes a second throttling element 302, which is located in the second pipe 32 and is disposed between the outlet of the condenser 2 and node O. The refrigeration system also includes:

[0093] The second temperature sensor 7, located between the second heat exchange chamber 5 and the air intake 11, is configured to detect the second temperature of the refrigerant in order to adjust the opening of the second throttling element 302.

[0094] Specifically, the opening of the second throttling device is adjusted according to the difference between the second temperature of the refrigerant and the evaporation temperature. For example, the second temperature can be T2, and the evaporation temperature of the evaporator can be T3. When T2-T3>c+d% (c and d are set values), the opening of the second throttling device 302 is reduced to reduce the amount of refrigerant entering the second heat exchange chamber 5; when T2-T3<c+d% (c and d are set values), the opening of the second throttling device 302 is increased to increase the amount of refrigerant entering the second heat exchange chamber 5; when cd%≤T2-T3≤c+d% (c and d are set values), there is no need to adjust the opening of the second throttling device 302.

[0095] This embodiment detects the second temperature of the refrigerant to adjust the opening of the second throttling device. By controlling the refrigerant flow through two throttling paths using dual-suction temperature sensing overheat control, the refrigerant flow in the second heat exchange chamber can be reasonably controlled. This prevents the compressor from liquid slugging due to excessive refrigerant flow into the second heat exchange chamber. Furthermore, by throttling the second pipeline, more refrigerant can flow into the second heat exchange chamber to evaporate and absorb heat without liquid slugging, significantly reducing the condensing temperature and improving the energy efficiency of the refrigeration system.

[0096] Secondly, this disclosure also proposes a control method for a refrigeration system based on the above embodiments, including:

[0097] Calculate the first difference between the first temperature and the evaporation temperature of evaporator 4;

[0098] Compare the first difference with the first preset range:

[0099] If the first difference is greater than the maximum value of the first preset range, the opening degree of the first throttling element 301 is increased;

[0100] If the first difference is less than the minimum value of the first preset range, the opening degree of the first throttling element 301 is reduced.

[0101] When the first difference is within the first preset range, the opening degree of the first throttling element 301 is kept unchanged.

[0102] Specifically, the evaporation temperature of evaporator 4 is calculated by monitoring the evaporation pressure of evaporator 4 through the controller of the refrigeration system. The specific calculation method can be found in relevant industry reference books. Specifically, the first difference between the first temperature and the evaporation temperature of evaporator 4 can be called the suction superheat. Specifically, after compressor 1 starts, the opening of the first throttling element 301 is adjusted according to the first difference.

[0103] The control method of this embodiment automatically adjusts the opening of the first throttling element by calculating the first difference, which can achieve reasonable control of the refrigerant flow in the evaporator, so that the evaporator will not be affected by insufficient refrigerant flow.

[0104] In some embodiments, such as Figure 1 and Figure 3 As shown, the throttling assembly 3 also includes a second throttling element 302, which is located in the second pipe 32 and is disposed between the outlet of the condenser 2 and node O. The refrigeration system also includes a second temperature sensor 7, which is disposed in the pipe between the second heat exchange chamber 5 and the suction port 11. The second temperature sensor 7 is configured to detect the second temperature of the refrigerant. The control method also includes:

[0105] Calculate the second difference between the second temperature and the evaporation temperature;

[0106] Compare the second difference with the second preset range:

[0107] If the second difference is greater than the maximum value of the second preset range, the opening of the second throttling element 302 is reduced;

[0108] If the second difference is less than the minimum value of the second preset range, the opening degree of the second throttling element 302 is increased;

[0109] When the second difference is within the second preset range, the opening degree of the second throttling element 302 is kept unchanged.

[0110] Specifically, the evaporation temperature of evaporator 4 is calculated by monitoring the evaporation pressure of evaporator 4 through the controller of the refrigeration system. The specific calculation method can be found in relevant industry reference books. Specifically, the second difference between the second temperature and the evaporation temperature of evaporator 4 can also be called the suction superheat. Specifically, after compressor 1 starts, the opening of the second throttling element 302 is adjusted according to the second difference.

[0111] This embodiment solves the refrigerant distribution problem in dual-throttling by calculating a first difference to adjust the opening of the first throttling element and calculating a second difference to adjust the opening of the second throttling element. It prevents the evaporator from being affected by insufficient refrigerant flow, thus preventing the compressor from liquid slugging in the second heat exchange chamber due to excessive refrigerant flow. Furthermore, by throttling the second pipeline, more refrigerant can flow into the second heat exchange chamber for evaporation and heat absorption without liquid slugging, significantly reducing the condensing temperature and improving the energy efficiency of the refrigeration system.

[0112] The refrigeration system and its control method provided in this disclosure have been described in detail above. Specific embodiments have been used to illustrate the principles and implementation methods of this disclosure. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications to this disclosure without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this disclosure.

Claims

1. A refrigeration system, characterized in that, include: The compressor (1) includes an intake port (11) and an exhaust port (12). The condenser (2) has a first heat exchange chamber (21) and a second heat exchange chamber (5), the exhaust port (12) is connected to the first heat exchange chamber (21), the second heat exchange chamber (5) is connected to the intake port (11), and the second heat exchange chamber (5) is disposed in the first heat exchange chamber (21) and configured to exchange heat with the refrigerant in the first heat exchange chamber (21); Evaporator (4); The first pipe (31) is connected between the condenser (2) and the second heat exchange chamber (5), and the evaporator (4) is provided on the first pipe (31). The second pipe (32) is connected between the condenser (2) and the second heat exchange chamber (5), and the second pipe (32) bypasses the evaporator (4). A throttling assembly (3) is used to throttle the refrigerant passing through the first pipe (31) and the second pipe (32). The throttling assembly (3) includes a first throttling element (301) and a second throttling element (302). The first throttling element (301) is located in the first pipe (31) and is disposed between the outlet of the condenser (2) and the inlet of the evaporator (4). The first pipe (31) has a node (O) connected to the second pipe (32) downstream of the outlet of the evaporator (4). The second throttling element (302) is located in the second pipe (32) and is disposed between the outlet of the condenser (2) and the node (O). A first temperature sensor (6), located on the pipe between the node (O) and the outlet of the evaporator (4), is configured to detect a first temperature of the refrigerant in order to adjust the opening of the first throttling element (301); and The second temperature sensor (7), located between the second heat exchange chamber (5) and the air intake (11), is configured to detect the second temperature of the refrigerant in order to adjust the opening of the second throttling element (302).

2. The refrigeration system according to claim 1, characterized in that, The second heat exchange chamber (5) is located in the middle and lower region of the first heat exchange chamber (21).

3. The refrigeration system according to claim 1, characterized in that, The condenser (2) includes a first heat exchange tube, which is disposed in the first heat exchange chamber (21) and a cooling medium flows through the first heat exchange tube. The second heat exchange chamber (5) is spaced apart from the first heat exchange tube.

4. The refrigeration system according to claim 3, characterized in that, The second heat exchange chamber (5) includes a second heat exchange tube, and the refrigerant in the second heat exchange tube exchanges heat with the refrigerant in the first heat exchange chamber (21) in a countercurrent manner.

5. The refrigeration system according to claim 1, characterized in that, The adjustment of the first pipeline (31) by the first throttling device (301) and the adjustment of the second pipeline (32) by the second throttling device (302) are independent of each other.

6. The refrigeration system according to claim 1, characterized in that, The first pipe (31) and the second pipe (32) have a common pipe between the outlet of the condenser (2) and the inlet of the evaporator (4), the first throttling element (301) is provided on the common pipe, and the second throttling element (302) is located on a length segment outside the common pipe.

7. A control method for a refrigeration system according to any one of claims 1 to 6, characterized in that, include: Calculate the first difference between the first temperature and the evaporation temperature of the evaporator (4); Compare the first difference with the first preset range: If the first difference is greater than the maximum value of the first preset range, the opening degree of the first throttling device (301) is increased; If the first difference is less than the minimum value of the first preset range, the opening degree of the first throttling element (301) is reduced; When the first difference is within the first preset range, the opening degree of the first throttling element (301) remains unchanged.

8. The control method according to claim 7, characterized in that, The throttling assembly (3) further includes a second throttling element (302), which is located in the second pipe (32) and disposed between the outlet of the condenser (2) and the node (O). The refrigeration system further includes a second temperature sensor (7), which is disposed in the pipe between the second heat exchange chamber (5) and the suction port (11). The second temperature sensor (7) is configured to detect a second temperature of the refrigerant. The control method further includes: Calculate the second difference between the second temperature and the evaporation temperature; Compare the second difference with the second preset range: If the second difference is greater than the maximum value of the second preset range, the opening degree of the second throttling element (302) is reduced; When the second difference is less than the minimum value of the second preset range, the opening degree of the second throttling element (302) is increased; When the second difference is within the second preset range, the opening degree of the second throttling element (302) remains unchanged.

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