cooling unit

Abstract

The application relates to a cooling unit. The cooling unit comprises a compressor, an outdoor heat exchanger, a first throttling device, a second throttling device, an intermediate heat exchanger and an indoor heat exchanger, the intermediate heat exchanger has a first input end and a first output end in fluid communication, and a second input end and a second output end in fluid communication; in a normal refrigeration state, the compressor, the outdoor heat exchanger, the first throttling device, the first input end, the first output end and the indoor heat exchanger are sequentially connected and form a circulation loop; in a high-temperature refrigeration state, the compressor, the outdoor heat exchanger, the first throttling device, the first input end, the first output end, the second throttling device and the indoor heat exchanger are sequentially connected and form a circulation loop; and the compressor, the second input end, the second output end and the second throttling device are sequentially connected and form a circulation loop. The cooling unit in the application has a large refrigerating capacity while realizing high-pressure protection.

Description

Technical Field

[0001] This application relates to the field of refrigeration technology, and in particular to a cooling unit. Background Technology

[0002] Currently, many cooling units on the market experience problems during operation. When the ambient temperature is too high, the pressure and temperature of the refrigerant output by the compressor are relatively high, increasing the heat load on the outdoor heat exchanger. This can easily trigger the high-pressure protection of the cooling unit, causing it to malfunction and fail to operate normally.

[0003] To avoid this situation, some existing cooling unit systems have added a hot gas bypass pipe. The hot gas bypass pipe can reduce the heat load on the outdoor heat exchanger and prevent the cooling unit from triggering high-pressure protection. However, opening the hot gas bypass pipe can also cause the cooling unit's cooling capacity to be insufficient to meet the cooling demand.

[0004] Therefore, how to increase the cooling capacity while implementing high-pressure protection has become an urgent problem to be solved. Summary of the Invention

[0005] In view of the above problems, a cooling unit is provided according to various embodiments of this application.

[0006] A cooling unit, the cooling unit having a normal cooling state and a high-temperature cooling state, and the cooling unit comprising:

[0007] The compressor, outdoor heat exchanger, first throttling device, second throttling device, intermediate heat exchanger and indoor heat exchanger, wherein the intermediate heat exchanger has a first input end and a first output end in fluid communication, and a second input end and a second output end in fluid communication;

[0008] When in the normal cooling state, the compressor, the outdoor heat exchanger, the first throttling device, the first input terminal, the first output terminal and the indoor heat exchanger are connected in sequence to form a circulation loop;

[0009] When the cooling unit is in the high-temperature cooling state, the compressor, the outdoor heat exchanger, the first throttling device, the first input terminal, the first output terminal, the second throttling device, and the indoor heat exchanger are connected in sequence to form a circulation loop;

[0010] Furthermore, the compressor, the second input terminal, the second output terminal, and the second throttling device are connected in sequence to form a circulation loop.

[0011] In some embodiments, the cooling unit also has an energy-saving cooling state, in which the compressor, the outdoor heat exchanger, the first throttling device, the first input terminal, the first output terminal and the indoor heat exchanger are connected in sequence to form a circulation loop;

[0012] The compressor is connected to the second input terminal, and when the outlet temperature T of the indoor heat exchanger... 出 Condition met: -0.1℃≤T 出 - When T≤0.1℃, the compressor is disconnected from the second input terminal, where T is the set refrigeration temperature value.

[0013] In some embodiments, the system further includes a first pipe connecting the compressor and the outdoor heat exchanger, a second pipe connecting the first pipe and the second input terminal, a third pipe, a fourth pipe connecting the first output terminal and the third pipe, a fifth pipe connecting the second output terminal and the third pipe, a first valve connected to the second pipe, and a second valve connected to the fifth pipe.

[0014] When the cooling unit is in the normal cooling state, both the first valve and the second valve are closed.

[0015] When the cooling unit is in the high-temperature refrigeration state, both the first valve and the second valve are open.

[0016] When the cooling unit is in the energy-saving cooling state, the first valve is open and the second valve is closed, and when T 出 Condition met: -0.1℃≤T 出 - When T≤0.1℃, the first valve is closed.

[0017] In some embodiments, it further includes a sixth pipe connected to the input end of the indoor heat exchanger, a seventh pipe and an eighth pipe arranged in parallel between the third pipe and the sixth pipe, a third valve connected to the seventh pipe, and a fourth valve and the second throttling device connected to the eighth pipe;

[0018] When the system is in the normal cooling state and the energy-saving cooling state, the third valve is open and the fourth valve is closed.

[0019] When in the high-temperature cooling state, the third valve is closed and the fourth valve is open.

[0020] In some embodiments, when the cooling unit switches from the energy-saving cooling state to the normal cooling state, the second valve is opened for at least 15 seconds and then closed.

[0021] In some embodiments, when the cooling unit switches from the high-temperature cooling state to the normal cooling state, the first valve closes at least 5 seconds earlier than the second valve.

[0022] In some embodiments, a pressure detection device is also included, which is disposed on the first pipe and located upstream of the second pipe in the direction of refrigerant flow in the first pipe. The pressure detection device is used to detect the pressure value in the first pipe, and when the pressure value is greater than the preset pressure threshold, the cooling unit switches to the high-temperature cooling state.

[0023] In some embodiments, a temperature detection element is also included. The temperature detection element is disposed on the indoor heat exchanger and is used to detect the temperature value at the inlet of the indoor heat exchanger. When the difference ΔT between the inlet temperature value and the set cooling temperature value satisfies the condition: ΔT ≥ high temperature set difference, the cooling unit enters the high temperature cooling state.

[0024] In some embodiments, a temperature detection element is also included. The temperature detection element is disposed on the indoor heat exchanger and is used to detect the temperature value at the inlet of the indoor heat exchanger. When the difference ΔT between the inlet temperature value and the set cooling temperature value meets the condition 0℃<ΔT≤2℃ and ΔT′≥0 within a first preset time period, the cooling unit switches to the energy-saving cooling state.

[0025] Where ΔT is T 进 The difference between T and T, ΔT′ is the difference of ΔT spanning a unit time, where T is the time interval. 进 The temperature value at the inlet of the indoor heat exchanger.

[0026] In some embodiments, a temperature detection element is also included. The temperature detection element is disposed on the indoor heat exchanger and is used to detect the temperature value at the inlet of the indoor heat exchanger. When the difference ΔT between the temperature value at the inlet and the set cooling temperature value meets the condition 2℃<ΔT<high temperature set difference within a second preset time period, the cooling unit switches to the normal cooling state.

[0027] Where ΔT is T 进 The difference between T and T, T 进 The temperature value at the inlet of the indoor heat exchanger.

[0028] The aforementioned cooling unit, by incorporating a second throttling device, can further reduce the temperature of the refrigerant before it flows into the indoor heat exchanger, thereby improving the cooling capacity of the unit. When the ambient temperature of the cooling unit is high, resulting in high refrigerant pressure and temperature at the compressor output, the compressor output pressure can be divided by connecting it to the second input terminal. This reduces the heat load flowing through the outdoor heat exchanger, thus providing high-pressure protection for the cooling unit and offering better reliability and safety.

[0029] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0030] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0031] Figure 1 This is a schematic diagram of the overall structure of the cooling unit in some embodiments of this application.

[0032] Figure 2 for Figure 1 The diagram shows the flow chart of the pressure detection device in the cooling unit during operation.

[0033] Figure 3 for Figure 1 The diagram shows a flow chart of the temperature detection element during operation in one embodiment of the cooling unit.

[0034] Figure 4 for Figure 1 A schematic diagram of the operation of the temperature detection element in another embodiment of the cooling unit shown.

[0035] Figure 5 for Figure 1 The diagram shows the operation of the temperature detection element in another embodiment of the cooling unit.

[0036] Icon labels:

[0037] 1. Cooling unit; 11. Compressor; 12. Outdoor heat exchanger; 13. First throttling device; 14. Second throttling device; 15. Intermediate heat exchanger; 151. First input end; 152. Second input end; 153. First output end; 154. Second output end; 16. Indoor heat exchanger; 161. Inlet; 162. Outlet; 17. Filter element; 18. First pipe; 19. Second pipe; 21. Third pipe; 22. Fourth pipe; 25. Fifth pipe; 26. Sixth pipe; 27. Seventh pipe; 28. Eighth pipe; 29. ​​First valve; 31. Second valve; 32. Third valve; 33. Fourth valve; 34. Pressure detection element; 35. Temperature detection element; 36. Temperature acquisition element; 37. Fan; 2. Load end. Detailed Implementation

[0038] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0039] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and 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, and therefore should not be construed as a limitation of this application.

[0040] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0042] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0044] This application provides a cooling unit that can be used for both domestic and industrial refrigeration. When used as a domestic refrigeration unit, the cooling system cools indoor air; when used as an industrial refrigeration unit, the cooling system cools fluids such as lubricating oil or coolant. For ease of explanation, the following embodiments all use indoor air as an example for the cooling system's cooling system.

[0045] See Figure 1 , Figure 1A schematic diagram of a cooling unit according to an embodiment of this application is shown. The cooling unit provided in this embodiment has a normal cooling state and a high-temperature cooling state. The cooling unit includes a compressor, an outdoor heat exchanger, a first throttling device, a second throttling device, an intermediate heat exchanger, and an indoor heat exchanger. The intermediate heat exchanger has a first input end and a first output end in fluid communication, and a second input end and a second output end in fluid communication. When the cooling unit is in the normal cooling state, the compressor, outdoor heat exchanger, first throttling device, first input end, first output end, and indoor heat exchanger are sequentially connected to form a circulation loop. When the cooling unit is in the high-temperature cooling state, the compressor, outdoor heat exchanger, first throttling device, first input end, first output end, second throttling device, and indoor heat exchanger are sequentially connected to form a circulation loop, and the compressor, second input end, second output end, and second throttling device are sequentially connected to form a circulation loop.

[0046] The first input terminal and the first output terminal are fluidly connected, meaning that the refrigerant flowing in from the first input terminal flows directly out from the first output terminal. The second input terminal and the second output terminal are fluidly connected, meaning that the refrigerant flowing in from the second input terminal flows directly out from the second output terminal. Furthermore, the channels formed by the connections between the first and first input terminals and the second input and second output terminals are independent of each other and do not interfere with each other. Thus, the refrigerant flowing in from the first input terminal and the refrigerant flowing in from the second input terminal only exchange heat, but they cannot mix.

[0047] Normal cooling mode is generally used when the ambient temperature of the cooling unit is not too high and the load on the indoor heat exchanger is moderate. The load end of the indoor heat exchanger is the end where the cooling object is located. The higher the temperature of the object being cooled, the higher the load on the cooling unit's load end will be.

[0048] In normal cooling mode, the compressor compresses the refrigerant into a high-temperature, high-pressure gaseous state, which is then delivered to the outdoor heat exchanger. The cooling unit also includes a fan. Under the action of the fan, outdoor air enters the outdoor heat exchanger and exchanges heat with the gaseous refrigerant, forming a medium-temperature, high-pressure liquid refrigerant. This medium-temperature, high-pressure liquid refrigerant then enters the first throttling device to reduce its pressure and form a low-temperature, low-pressure liquid refrigerant. Subsequently, as it flows through the indoor heat exchanger, the low-temperature, low-pressure liquid refrigerant absorbs heat from the indoor air, forming a gaseous refrigerant, which is then ultimately recycled back to the compressor for further compression.

[0049] High-temperature cooling mode is generally used when the ambient temperature of the cooling unit is high and / or the load on the indoor heat exchanger is large. When the ambient temperature of the cooling unit rises to a certain level and / or the load on the indoor heat exchanger increases, the cooling unit switches to high-temperature cooling mode.

[0050] When in high-temperature cooling mode, a portion of the high-temperature, high-pressure gaseous refrigerant formed by the compressor flows sequentially through the outdoor heat exchanger and the first throttling device, forming a low-temperature, low-pressure liquid refrigerant which then flows into the intermediate heat exchanger from the first input end. Simultaneously, the remaining high-temperature, high-pressure gaseous refrigerant from the compressor flows into the intermediate heat exchanger from the second input end, exchanging heat with the liquid refrigerant flowing in from the first input end. The gaseous refrigerant input from the second input end is at a higher temperature than the low-temperature, low-pressure liquid refrigerant flowing in from the first input end. After heat exchange in the intermediate heat exchanger, the low-temperature, low-pressure liquid refrigerant's temperature rises and it is output from the first output end, while the high-temperature, high-pressure gaseous refrigerant's temperature decreases and it is output from the second output end. Subsequently, both the heated liquid refrigerant output from the first output end and the cooled gaseous refrigerant output from the second output end flow through the second throttling device, forming low-temperature, low-pressure liquid refrigerant before being output to the indoor heat exchanger. Low-temperature, low-pressure liquid refrigerant can absorb more heat to meet the cooling capacity requirements of larger loads and / or high-temperature environments. Understandably, the low-temperature, low-pressure refrigerant formed after flowing through the second throttling device has a lower temperature and lower pressure than the low-temperature, low-pressure refrigerant formed after flowing through the first throttling device.

[0051] It's worth noting that for residential refrigeration, since the load is indoor air, the high indoor temperature is the primary cause of increased load. However, for industrial refrigeration, the refrigerated substance may be non-airy materials such as lubricating oil. Therefore, while high temperature can increase the load, it's not the main cause. The main reasons for increased load are likely prolonged operation of industrial equipment or high-power output from industrial equipment.

[0052] In traditional cooling units, during high-temperature cooling, the compressor, outdoor heat exchanger, first throttling device, and indoor heat exchanger are connected sequentially to form a circulation loop, with a hot gas bypass pipe connecting the compressor's output and the indoor heat exchanger's input. In this state, a portion of the high-temperature, high-pressure gaseous refrigerant compressed by the compressor passes through the outdoor heat exchanger and the first throttling device, forming a low-temperature, low-pressure liquid refrigerant which then flows into the indoor heat exchanger. The remaining high-temperature, high-pressure gaseous refrigerant flows directly into the indoor heat exchanger through the hot gas bypass pipe, where it exchanges heat with the low-temperature, low-pressure liquid refrigerant flowing in from the first throttling device. While this method reduces the heat load on the outdoor heat exchanger, the heat exchange between the high-temperature, high-pressure gaseous refrigerant and the low-temperature, low-pressure liquid refrigerant in the indoor heat exchanger causes the temperature of the liquid refrigerant to rise, resulting in a decrease in the amount of heat absorbed by the liquid refrigerant (less heat absorbed from the object being cooled), thus reducing the cooling capacity of the cooling unit.

[0053] However, when the cooling unit switches to high-temperature cooling mode, the load on the load side is generally larger, and / or the ambient temperature of the cooling unit is higher. In this case, the required cooling capacity of the cooling unit should be higher. However, because the cooling capacity decreases when the cooling unit switches to high-temperature cooling mode, the cooling capacity of the cooling unit does not match the actual required cooling capacity. In this application, by setting a second throttling device, the temperature of the refrigerant before it flows into the indoor heat exchanger can be further reduced, thereby helping to increase the cooling capacity of the cooling unit.

[0054] Meanwhile, when the ambient temperature of the cooling unit is high, resulting in high refrigerant pressure and temperature at the compressor output, the compressor output pressure can be divided by connecting the compressor to the second input terminal to reduce the heat load flowing through the outdoor heat exchanger. This provides high-pressure protection for the cooling unit and offers better reliability and safety.

[0055] The intermediate heat exchanger allows the high-temperature, high-pressure gaseous refrigerant input from the compressor to the intermediate heat exchanger to exchange heat with the low-temperature, low-pressure liquid refrigerant input from the first throttling device, thus lowering their temperature. This brings the temperatures of the refrigerant input from the first and second input terminals closer together. Furthermore, the refrigerant input from the first and second input terminals, after being throttled and depressurized in the second throttling device, can combine to form a lower-temperature, lower-pressure liquid refrigerant, resulting in better cooling efficiency.

[0056] In some embodiments of this application, the cooling unit also has an energy-saving cooling state. When in the energy-saving cooling state, the compressor, outdoor heat exchanger, first throttling device, first input terminal, first output terminal and indoor heat exchanger are connected in sequence to form a circulation loop.

[0057] The compressor is connected to the second input terminal, and when the outlet temperature T of the indoor heat exchanger... 出 Condition met: -0.1℃≤T 出 - When T≤0.1℃, the compressor is disconnected from the second input terminal, where T is the set cooling temperature value.

[0058] The energy-saving cooling mode is generally applicable when the ambient temperature of the cooling unit is not high and / or the load on the load side of the indoor heat exchanger is relatively small.

[0059] Understandably, the load at the load end in energy-saving cooling mode is less than the load at the load end in normal cooling mode, and the load at the load end in normal cooling mode is less than the load at the load end in high-temperature cooling mode.

[0060] In energy-saving cooling mode, a portion of the high-temperature, high-pressure gaseous refrigerant generated by the compressor flows sequentially through the outdoor heat exchanger, the first throttling device, the first input terminal, the first output terminal, and the indoor heat exchanger before circulating back into the compressor. Simultaneously, the remaining high-temperature, high-pressure gaseous refrigerant from the compressor flows into the intermediate heat exchanger through the second input terminal, where it exchanges heat with the gaseous refrigerant flowing in from the first input terminal. The gaseous refrigerant input from the second input terminal has a higher temperature than the low-temperature, low-pressure liquid refrigerant flowing in from the first input terminal. After heat exchange in the intermediate heat exchanger, the low-temperature, low-pressure liquid refrigerant's temperature rises and it is output from the first output terminal, while a portion of the high-temperature, high-pressure gaseous refrigerant condenses into liquid and is collected in the intermediate heat exchanger, no longer participating in the circulation. The remaining uncondensed gaseous refrigerant fills the intermediate heat exchanger and / or connects to the pipes between the compressor and the second input terminal.

[0061] As time goes on, and when the outlet temperature T of the indoor heat exchanger increases... 出 Condition met: -0.1℃≤T 出 - When T ≤ 0.1℃, the compressor is disconnected from the second input terminal, where T is the set cooling temperature value, i.e., the temperature that the user wants the object to reach for cooling. The indoor heat exchanger includes a shell and an indoor heat exchange component. The shell has a cavity inside, and an inlet and an outlet communicating with the cavity are opened on the shell. The indoor heat exchange component is located inside the shell. The indoor heat exchange component is the main functional component of the indoor heat exchanger, and its output terminal is always connected to the compressor.

[0062] In normal and energy-saving cooling states, the inlet of the indoor heat exchanger is connected to the first outlet. In high-temperature cooling state, the inlet of the indoor heat exchanger is connected to the second throttling device. When the cooling unit is working, the cooling fluid enters through the inlet, exchanges heat with the indoor heat exchanger inside the outer shell, and then flows out to the outside through the outlet. When the outlet temperature T of the indoor heat exchanger... 出 Condition met: -0.1℃≤T 出 When T≤0.1℃, it indicates that the temperature of the object being refrigerated by the cooling unit is close to the set refrigeration temperature. At this point, the cooling capacity of the refrigerant circulating in the loop formed by the compressor, outdoor heat exchanger, first throttling device, first input terminal, first output terminal, and indoor heat exchanger meets the requirements. Then, disconnecting the compressor from the second input terminal allows the refrigerant to circulate only in the loop formed by the compressor, outdoor heat exchanger, first throttling device, first input terminal, first output terminal, and indoor heat exchanger. The condensed refrigerant is collected in the intermediate heat exchanger and no longer participates in the circulation. Thus, while ensuring the cooling capacity meets the low-load demand, the refrigerant circulation flow rate is reduced, resulting in superior energy-saving performance.

[0063] It is worth mentioning that in this application, a temperature acquisition device can be installed at the outlet of the indoor heat exchanger. This device is used to collect the temperature value at the outlet of the indoor heat exchanger in real time. The cooling unit also includes a controller, which is electrically connected to the temperature acquisition device. The device feeds back the collected temperature value at the outlet of the indoor heat exchanger to the controller, which then controls whether the compressor is disconnected from the second input terminal based on the temperature value at the outlet of the indoor heat exchanger. Specifically, when -0.1℃ ≤ T 出 - When T≤0.1℃, the controller disconnects the compressor from the second input terminal. 出 - T > 0.1℃, or T 出 If T is less than -0.1℃, the controller will keep the compressor connected to the second input terminal.

[0064] In some embodiments of this application, the cooling unit further includes a first pipe connecting the compressor and the outdoor heat exchanger, a second pipe connecting the first pipe and the second input terminal, a third pipe, a fourth pipe connecting the first output terminal and the third pipe, and a fifth pipe connecting the second output terminal and the third pipe, a first valve connected to the second pipe, and a second valve connected to the fifth pipe. When the cooling unit is in normal cooling mode, both the first and second valves are closed; when the cooling unit is in high-temperature cooling mode, both the first and second valves are open; when the cooling unit is in energy-saving cooling mode, the first valve is open and the second valve is closed, and when T... 出 Condition met: -0.1℃≤T 出 - When T≤0.1℃, the first valve is closed.

[0065] When the cooling unit is in normal cooling mode, both the first valve and the second valve are closed. The high-temperature and high-pressure refrigerant output by the compressor flows sequentially through the outdoor heat exchanger, the first throttling device, the first input end, the first output end, and the indoor heat exchanger before returning to the compressor for internal circulation and normal cooling.

[0066] When the cooling unit is in high-temperature cooling mode, the first and second valves open, and a portion of the high-temperature, high-pressure refrigerant output from the compressor flows sequentially through the outdoor heat exchanger, the first throttling device, the first input terminal, and the first output terminal into the third pipe. Simultaneously, the remaining high-temperature, high-pressure refrigerant output from the compressor flows sequentially through the second input terminal, the second output terminal, and the fifth pipe into the third pipe. This reduces the heat load flowing through the outdoor heat exchanger, thereby providing high-pressure protection for the cooling unit.

[0067] When the cooling unit is in energy-saving cooling mode, the first valve is open and the second valve is closed. A portion of the high-temperature, high-pressure gaseous refrigerant generated by the compressor flows sequentially through the outdoor heat exchanger, the first throttling device, the first input end, the first output end, and the indoor heat exchanger, circulating back into the compressor. Simultaneously, the remaining high-temperature, high-pressure gaseous refrigerant from the compressor flows into the intermediate heat exchanger through the second input end. There, it exchanges heat with the gaseous refrigerant flowing into the intermediate heat exchanger from the first input end, condensing into liquid refrigerant which is collected within the intermediate heat exchanger. Over time, the amount of condensed liquid refrigerant in the intermediate heat exchanger gradually increases, and the outlet temperature T of the indoor heat exchanger rises. 出 It also gradually approaches T. When the outlet temperature T of the indoor heat exchanger 出 Condition met: -0.1℃≤T 出 When T≤0.1℃, it indicates that the temperature of the object being refrigerated by the cooling unit is close to the set refrigeration temperature. At this point, the cooling capacity of the refrigerant circulating in the loop formed by the compressor, outdoor heat exchanger, first throttling device, first input terminal, first output terminal, and indoor heat exchanger meets the requirements. Disconnecting the compressor from the second input terminal at this time ensures that the cooling capacity meets the demand while reducing the refrigerant circulation flow, resulting in superior energy savings.

[0068] By setting up a first pipe, a second pipe, a third pipe, a fourth pipe, a fifth pipe, a first valve, and a second valve, the refrigerant in each circulation loop will not cross-flow, and the cooling unit can reliably switch between different states.

[0069] In some embodiments of this application, the cooling unit further includes a sixth pipe connected to the input end of the indoor heat exchanger, a seventh pipe and an eighth pipe connected in parallel between the third pipe and the sixth pipe, a third valve connected to the seventh pipe, and a fourth valve and a second throttling device connected to the eighth pipe. In normal cooling mode and energy-saving cooling mode, the third valve is open and the fourth valve is closed; in high-temperature cooling mode, the third valve is closed and the fourth valve is open.

[0070] When the cooling unit is in normal cooling mode, the third valve is open and the fourth valve is closed. The high-temperature and high-pressure refrigerant output by the compressor flows sequentially through the outdoor heat exchanger, the first throttling device, the first input end, the first output end, and the indoor heat exchanger before returning to the compressor for internal circulation and normal cooling.

[0071] When the cooling unit is in a high-temperature cooling state, the third valve is closed and the fourth valve is open. All refrigerants in the third pipe can flow through the second throttling device for throttling and pressure reduction, ensuring that the cooling unit has a high cooling capacity and cooling efficiency.

[0072] When the cooling unit is in energy-saving cooling mode, the third valve is open and the fourth valve is closed. The refrigerant output from the first output end and the refrigerant output from the second output end both pass through the room and refrigerate the object being cooled at the load end of the indoor heat exchanger before circulating back into the compressor.

[0073] By setting up the sixth, seventh, and eighth pipes, the third valve, and the fourth valve, the refrigerant between each circulation loop does not cross-flow, and the cooling unit can reliably switch between different states.

[0074] In some embodiments of this application, when the cooling unit switches from energy-saving cooling state to normal cooling state, the second valve is opened for at least 15 seconds and then closed.

[0075] Understandably, when the cooling unit is in energy-saving cooling mode, some of the condensed refrigerant is collected in the intermediate heat exchanger, resulting in a reduction in the amount of refrigerant circulating within the cooling unit. When the cooling unit switches to normal operating mode, the cooling capacity required for normal operating mode is greater than that required for energy-saving cooling mode. In this case, when switching from the cooling unit to normal operating mode, the second valve is opened, allowing the condensed liquid refrigerant in the intermediate heat exchanger to flow through the second inlet and the fifth pipe to the third pipe. Ultimately, it circulates through the compressor, outdoor heat exchanger, first throttling device, first inlet, first outlet, and indoor heat exchanger, forming a loop, thereby increasing the cooling capacity of the cooling unit and meeting the demand.

[0076] Therefore, it can be seen that the second valve is opened for at least 15 seconds and then closed, which helps to discharge as much of the liquid refrigerant condensed in the intermediate heat exchanger as possible into the third pipe, thereby effectively improving the cooling capacity of the cooling unit.

[0077] In some embodiments of this application, when the cooling unit switches from a high-temperature cooling state to a normal cooling state, the first valve closes at least 5 seconds earlier than the second valve.

[0078] The first valve closes before the second valve, effectively blocking the high-temperature, high-pressure gaseous refrigerant from being fed into the intermediate heat exchanger by the compressor. This prevents the refrigerant from condensing and forming liquid refrigerant within the intermediate heat exchanger before the state transition. Furthermore, the first valve closes at least 5 seconds before the second valve, allowing as much of the condensed liquid refrigerant in the intermediate heat exchanger as possible to be discharged into the third pipe and used for circulating refrigeration, resulting in better cooling performance.

[0079] Please refer to it again. Figure 1 And see also Figure 2In some embodiments of this application, the cooling unit further includes a pressure detection element, which is disposed on the first pipe and located upstream of the second pipe in the direction of refrigerant flow in the first pipe. The pressure detection element is used to detect the pressure value in the first pipe, and when the pressure value is greater than a preset pressure threshold, the cooling unit switches to a high-temperature cooling state.

[0080] In other words, during actual operation, the high-temperature, high-pressure gaseous refrigerant flows through the pressure detection device before being diverted. The preset pressure threshold can be set according to the user's needs and experience. It is only necessary to ensure that the pressure value is greater than the preset pressure threshold, indicating that the ambient temperature of the cooling unit is high, requiring high-pressure protection and switching to high-temperature cooling mode.

[0081] The pressure detection element is used to monitor the pressure output by the compressor in real time so that the status can be switched in a timely manner.

[0082] Preferably, the first, second, third, and fourth valves are all solenoid valves. The cooling unit also includes a controller, which is connected to the pressure sensor, the first, second, third, and fourth valves. The pressure sensor feeds back the detected pressure to the controller, which compares the pressure detected by the pressure sensor with a preset pressure threshold. When the pressure value is greater than the preset pressure threshold, the controller controls the first, second, third, and fourth valves to operate, enabling the cooling unit to switch to a high-temperature cooling state. When the pressure value is less than or equal to the preset pressure threshold, the controller controls the cooling unit to maintain its current state.

[0083] By setting pressure detection devices, the cooling unit can be automatically monitored and its status can be automatically switched, resulting in a high degree of automation and a good user experience.

[0084] Please refer to the following: Figure 3 In some embodiments of this application, the cooling unit further includes a temperature detection element, which is disposed on the indoor heat exchanger and used to detect the temperature value at the inlet of the indoor heat exchanger. When the difference ΔT between the inlet temperature value and the set cooling temperature value satisfies the condition: ΔT ≥ high temperature set difference, the cooling unit enters the high temperature cooling state.

[0085] During actual operation of the cooling unit, the refrigerated object flows in through the inlet of the indoor heat exchanger, exchanges heat with the indoor heat exchanger components, and then flows out through the outlet of the indoor heat exchanger. Throughout the entire operation, the refrigerated object circulates between the environment of the cooling unit and the indoor heat exchanger; therefore, the temperature at the inlet of the indoor heat exchanger is the same as or approximately the same as the temperature of the refrigerated object before refrigeration.

[0086] Temperature sensors are used to monitor the temperature at the inlet of the indoor heat exchanger in real time. When the difference between this temperature and the set cooling temperature ΔT is greater than or equal to the high temperature set difference, it indicates that the temperature of the object being cooled is high, and the load on the load side of the indoor heat exchanger is large. At this time, the cooling unit needs to switch to high temperature cooling mode to meet the demand for a larger cooling capacity.

[0087] In this embodiment, the temperature sensor is electrically connected to the controller. The temperature sensor feeds back the detected temperature value to the controller. When the difference ΔT between the inlet temperature value and the set cooling temperature value is greater than or equal to the high-temperature set difference value, the controller controls the first valve, the second valve, the third valve, and the fourth valve to operate, so that the cooling unit can switch to the high-temperature cooling state. The high-temperature set difference value is a preset temperature value, which can be set based on user experience, or it can be a fixed value preset and stored in the controller before leaving the factory.

[0088] By setting temperature sensors, the cooling unit can be automatically monitored and its status can be automatically switched, resulting in a high degree of automation and a good user experience.

[0089] Please refer to the following: Figure 4 In some embodiments of this application, the cooling unit further includes a temperature detection element, which is disposed on the indoor heat exchanger and used to detect the inlet temperature of the indoor heat exchanger. When the inlet temperature and the set cooling temperature ΔT satisfy the following conditions within a first preset time period: 0℃<ΔT≤2℃, and ΔT′≥0, the cooling unit switches to energy-saving cooling mode; wherein, ΔT is T 进 The difference between T and T, ΔT′ is the difference of ΔT spanning a unit time, where T is the time interval. 进 This refers to the inlet temperature of the indoor heat exchanger.

[0090] Specifically, the first preset duration can be 10s, 12s, 15s, etc., and can be set as needed.

[0091] When the difference between the inlet temperature and the set cooling temperature is 0℃ < ΔT ≤ 2℃, it indicates that the current temperature of the uncooled object is greater than but close to the set cooling temperature. This means the load on the indoor heat exchanger is relatively small, and the required cooling capacity is also low. ΔT represents the temperature of the object being cooled (T). 进 The difference between -T and T is where Tin is the inlet temperature of the indoor heat exchanger and T is the set cooling temperature.

[0092] ΔT′≥0, where ΔT′ represents the difference in ΔT values ​​over a unit of time. For example, if the unit of time is defined as 2 seconds, then ΔT′ can be expressed as the difference in ΔT values ​​at 2-second intervals. Specifically, it represents the difference between ΔT values ​​2 seconds from the time reference zero and ΔT values ​​4 seconds from the time reference zero. The ΔT at 2 seconds represents the difference between the inlet temperature of the indoor heat exchanger and the set cooling temperature at 2 seconds from the time reference zero, and the ΔT at 4 seconds represents the difference between the inlet temperature of the indoor heat exchanger and the set cooling temperature at 4 seconds from the time reference zero. The time reference zero is a natural time point, which is the natural time point at which the test begins, such as 9:30 AM, 2 PM, etc. ΔT′≥0 indicates that as time progresses, the inlet temperature of the indoor heat exchanger is decreasing and gradually approaching the set cooling temperature.

[0093] When 0℃<ΔT≤2℃ and ΔT′≥0 is satisfied, the cooling unit switches to energy-saving refrigeration mode, which can not only meet the refrigeration needs, but also save energy and electricity.

[0094] Please refer to the following: Figure 5 In some embodiments of this application, the cooling unit further includes a temperature detection element, which is disposed on the indoor heat exchanger and used to detect the inlet temperature value of the indoor heat exchanger. When the inlet temperature value and the set cooling temperature value ΔT satisfy the condition 2℃ < ΔT < high temperature set difference within a second preset time period, the cooling unit switches to normal cooling state; wherein, ΔT is T 进 The difference between T and T, T 进 This refers to the inlet temperature of the indoor heat exchanger. The high-temperature setting difference is >2℃.

[0095] Specifically, the second preset duration can be the same as or different from the first preset duration. The following embodiments are all illustrated using the example where the second preset duration is the same as the first preset duration, and the second preset duration is 12s.

[0096] When the difference ΔT between the inlet temperature and the set cooling temperature meets the condition that 2℃ < ΔT < high-temperature set difference, it indicates that the current temperature of the uncooled object is relatively close. At this time, the required cooling capacity is higher than that in energy-saving cooling mode, but lower than that in high-temperature cooling mode. In this case, the cooling unit switches to normal cooling mode to meet the cooling demand.

[0097] Therefore, the temperature detection device can monitor the inlet temperature of the indoor heat exchanger in real time, so that the cooling unit can automatically switch between normal cooling mode, energy-saving cooling mode and high-temperature cooling mode.

[0098] In some embodiments, the cooling unit further includes a filter element connected between the outdoor heat exchanger and the first throttling device, used to filter water vapor in the refrigerant. The filter element ensures the dryness of the refrigerant, thereby improving the reliability of the cooling unit.

[0099] The aforementioned cooling unit, by incorporating a second throttling device, can further reduce the temperature of the refrigerant before it flows into the indoor heat exchanger, thereby improving the cooling capacity of the unit. When the ambient temperature of the cooling unit is high, resulting in high refrigerant pressure and temperature at the compressor output, the compressor output pressure can be divided by connecting it to the second input terminal. This reduces the heat load flowing through the outdoor heat exchanger, thus providing high-pressure protection for the cooling unit and offering better reliability and safety.

[0100] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A cooling unit, characterized in that, The cooling unit has a normal cooling state and a high-temperature cooling state, and the cooling unit includes: The compressor (11), outdoor heat exchanger (12), first throttling device (13), second throttling device (14), intermediate heat exchanger (15) and indoor heat exchanger (16), wherein the intermediate heat exchanger (15) has a first input end (151) and a first output end (153) in fluid communication, and a second input end (152) and a second output end (154) in fluid communication. When in the normal cooling state, the compressor (11), the outdoor heat exchanger (12), the first throttling device (13), the first input terminal (151), the first output terminal (153) and the indoor heat exchanger (16) are connected in sequence to form a circulation loop; When the cooling unit is in the high-temperature cooling state, the compressor (11), the outdoor heat exchanger (12), the first throttling device (13), the first input terminal (151), the first output terminal (153), the second throttling device (14), and the indoor heat exchanger (16) are connected in sequence to form a circulation loop. The compressor (11), the second input terminal (152), the second output terminal (154), the second throttling device (14) and the indoor heat exchanger (16) are connected in sequence to form a circulation loop.

2. The cooling unit according to claim 1, characterized in that, The cooling unit also has an energy-saving cooling state. When in the energy-saving cooling state, the compressor (11), the outdoor heat exchanger (12), the first throttling device (13), the first input terminal (151), the first output terminal (153) and the indoor heat exchanger (16) are connected in sequence to form a circulation loop. The compressor (11) is connected to the second input terminal (152), and when the temperature T at the outlet (162) of the indoor heat exchanger (16) is... 出 Condition met: -0.1℃≤T 出 When T≤0.1℃, the compressor (11) is disconnected from the second input terminal (152), where T is the set refrigeration temperature value.

3. The cooling unit according to claim 2, characterized in that, It also includes a first pipe (18) connecting the compressor (11) and the outdoor heat exchanger (12), a second pipe (19) connecting the first pipe (18) and the second input end (152), a third pipe (21), a fourth pipe (22) connecting the first output end (153) and the third pipe (21), and a fifth pipe (25) connecting the second output end (154) and the third pipe (21), a first valve (29) connected to the second pipe (19), and a second valve (31) connected to the fifth pipe (25); When the cooling unit is in the normal cooling state, both the first valve (29) and the second valve (31) are closed; When the cooling unit is in the high-temperature refrigeration state, both the first valve (29) and the second valve (31) are open; When the cooling unit is in the energy-saving cooling state, the first valve (29) is open and the second valve (31) is closed, and when T 出 Condition met: -0.1℃≤T 出 - When T≤0.1℃, the first valve (29) is closed.

4. The cooling unit according to claim 3, characterized in that, It also includes a sixth pipe (26) connected to the input end of the indoor heat exchanger (16), a seventh pipe (27) and an eighth pipe (28) arranged in parallel between the third pipe (21) and the sixth pipe (26), a third valve (32) connected to the seventh pipe (27), a fourth valve (33) connected to the eighth pipe (28), and the second throttling device (14). When in the normal cooling state and the energy-saving cooling state, the third valve (32) is open and the fourth valve (33) is closed; When in the high-temperature cooling state, the third valve (32) is closed and the fourth valve (33) is open.

5. The cooling unit according to claim 3, characterized in that, When the cooling unit switches from the energy-saving cooling state to the normal cooling state, the second valve (31) is opened for at least 15 seconds and then closed.

6. The cooling unit according to claim 3, characterized in that, When the cooling unit switches from the high-temperature cooling state to the normal cooling state, the first valve (29) closes at least 5 seconds earlier than the second valve (31).

7. The cooling unit according to claim 3, characterized in that, It also includes a pressure detection element (34), which is disposed on the first pipe (18) and located upstream of the second pipe (19) in the direction of refrigerant flow in the first pipe (18). The pressure detection element (34) is used to detect the pressure value in the first pipe (18), and when the pressure value is greater than a preset pressure threshold, the cooling unit switches to the high-temperature cooling state.

8. The cooling unit according to claim 2, characterized in that, It also includes a temperature detection element (35), which is installed on the indoor heat exchanger (16) and is used to detect the temperature value of the inlet (161) of the indoor heat exchanger (16). When the temperature value of the inlet (161) and the set cooling temperature value ΔT meet the condition: ΔT≥ high temperature set difference, the cooling unit enters the high temperature cooling state.

9. The cooling unit according to claim 2, characterized in that, It also includes a temperature detection element (35), which is installed on the indoor heat exchanger (16) and is used to detect the temperature value of the inlet (161) of the indoor heat exchanger (16). When the difference ΔT between the temperature value of the inlet (161) and the set cooling temperature value meets the condition of 0℃<ΔT≤2℃ and ΔT′≥0 within a first preset time period, the cooling unit switches to the energy-saving cooling state. Where ΔT is T 进 The difference between T and T, ΔT′ is the difference of ΔT spanning a unit time, where T is the time interval. 进 The temperature value of the inlet (161) of the indoor heat exchanger (16).

10. The cooling unit according to claim 2, characterized in that, It also includes a temperature detection element (35), which is installed on the indoor heat exchanger (16) and is used to detect the temperature value of the inlet (161) of the indoor heat exchanger (16). When the temperature value of the inlet (161) and the set cooling temperature value ΔT meet the condition of 2℃<ΔT<high temperature set difference within a second preset time period, the cooling unit switches to the normal cooling state. Where ΔT is T 进 The difference between T and T, T 进 The temperature value of the inlet (161) of the indoor heat exchanger (16).

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