Refrigeration system, medical low temperature storage box and anti-blocking method of refrigeration system

Abstract

The present disclosure relates to a refrigeration system, a medical cryogenic preservation box and a method for preventing refrigeration system from being blocked, wherein the refrigeration system comprises a first compressor, a first heat exchanger, a throttling assembly and a second heat exchanger; along the flow direction of the refrigerant, the first compressor, the first heat exchanger, the throttling assembly, the second heat exchanger and the first compressor are sequentially connected, wherein the throttling assembly comprises two capillaries connected in parallel, the two capillaries have the same length, and the two capillaries are configured to be in a working state at one time. The two capillaries have the same length, and one of them is in a working state at one time. When the capillary in the working state is blocked, the other capillary is switched to be in the working state to avoid the influence of oil blockage or ice blockage of the capillary on the refrigeration system, and to improve the adaptability of the capillary to the whole operation process of the refrigeration system.

Description

Technical Field

[0001] The present disclosure relates to the field of refrigeration technology, and in particular to a refrigeration system, a medical low-temperature preservation box, and a method for preventing the refrigeration system from being blocked. Background Art

[0002] For low-temperature refrigeration products, especially low-temperature refrigeration systems that use multi-stage refrigeration cycles, the lubricating oil in the system is difficult to flow due to the decrease in temperature and the increase in viscosity. When the compressor stops, the pressure difference at both ends of the capillary gradually disappears, and the temperature reaches the pour point of the lubricating oil, which is prone to accumulation and condensation of the lubricating oil. In addition, the lubricating oil easily absorbs water, and the water content of the system is difficult to effectively control within a low range. It will condense and form ice crystals in a low temperature environment. Therefore, the residual lubricating oil in the system refrigerant is likely to cause oil or ice blockage in the capillary, causing system failure. Summary of the invention

[0003] Some embodiments of the present disclosure provide a refrigeration system, a medical low-temperature preservation box, and a method for preventing refrigeration system blockage, which are used to alleviate the problem of refrigeration system blockage.

[0004] In one aspect of the present disclosure, a refrigeration system is provided, comprising a first compressor, a first heat exchanger, a throttling assembly, and a second heat exchanger; along the flow direction of the refrigerant, the first compressor, the first heat exchanger, the throttling assembly, the second heat exchanger and the first compressor are connected in sequence, wherein the throttling assembly comprises two capillaries connected in parallel, the two capillaries have the same length, and the two capillaries are configured to be in a working state one by one; each of the two capillaries comprises a first pipe segment and a second pipe segment connected in series, the first pipe segment is connected to the first heat exchanger, the second pipe segment is connected to the second heat exchanger, and the pipe diameter of the first pipe segment is smaller than the pipe diameter of the second pipe segment.

[0005] In some embodiments, the refrigeration system further includes two heating elements, and the two heating elements are configured to heat the two capillaries respectively in a one-to-one correspondence.

[0006] In some embodiments, the two heating elements extend spirally, and the two heating elements are respectively and one by one arranged in the cavity formed by the two capillary spirals.

[0007] In some embodiments, the refrigeration system further includes a controller, the controller being electrically connected to the two heating elements, and the controller being configured to control a heating temperature or a heating time of the capillary tube by the heating elements.

[0008] In some embodiments, the refrigeration system also includes a controller and two control valves, the two control valves are configured to control the two capillaries to be in a working state or a non-working state respectively, the controller is electrically connected to the two control valves, and the controller is configured to control one of the two control valves to open so that the capillary corresponding to the opened control valve is in a working state.

[0009] In some embodiments, the refrigeration system also includes a first temperature detection component and a second temperature detection component electrically connected to the controller, the first temperature detection component is configured to detect a first outlet temperature of the second heat exchanger, and the second temperature detection component is configured to detect the temperature in a space where the second heat exchanger is to perform heat exchange, the controller is configured to receive temperature signals detected by the first temperature detection component and the second temperature detection component, and when the first outlet temperature is greater than the temperature in the space, and the first outlet temperature continues to rise, and the heating rate is greater than or equal to a first preset value, or when the first outlet temperature is higher than the first preset temperature value, the control valve that is currently in an open state is controlled to be closed, and the control valve that is in a closed state is controlled to be opened.

[0010] In some embodiments, the refrigeration system also includes a third temperature detection component electrically connected to the controller, and the third temperature detection component is configured to detect a second outlet temperature of the throttling assembly. When the second outlet temperature is lower than that under normal operating conditions and the cooling rate is greater than or equal to a second preset value, or when the second outlet temperature is lower than the second preset temperature value, the control valve currently in the open state is controlled to be closed, and the control valve in the closed state is controlled to be opened.

[0011] In some embodiments, the refrigeration system further includes a second compressor, a third heat exchanger and a throttling device. Along the flow direction of the refrigerant, the second compressor, the third heat exchanger, the throttling device, the first heat exchanger and the second compressor are connected in sequence.

[0012] In one aspect of the present disclosure, there is provided a medical low-temperature preservation box, comprising:

[0013] A box body, in which a storage space for accommodating items is formed; and

[0014] In the above refrigeration system, the second heat exchanger is configured to cool the storage space.

[0015] In some embodiments, the medical low-temperature preservation box also includes a second compressor, a third heat exchanger and a throttling device arranged outside the box body. Along the flow direction of the refrigerant, the second compressor, the third heat exchanger, the throttling device, the first heat exchanger and the second compressor are connected in sequence.

[0016] In one aspect of the present disclosure, a method for preventing blocking of the above refrigeration system is provided, which comprises the following steps:

[0017] The first compressor is running, so that one of the two capillary tubes connected in parallel is in working state;

[0018] When a capillary in a working state is clogged, another capillary is switched to a working state.

[0019] In some embodiments, the anti-blocking method of the refrigeration system further includes a method for determining whether a capillary tube in a working state is blocked, which includes the following steps:

[0020] Detecting a first outlet temperature of the second heat exchanger by a first temperature detecting member;

[0021] Detecting the temperature of the space where the second heat exchanger is to perform heat exchange by means of a second temperature detection element;

[0022] When the first outlet temperature is greater than the temperature in the space, and the first outlet temperature continues to rise, and the heating rate is greater than or equal to a first preset value, or the first outlet temperature is higher than the first preset temperature value, it is determined that the capillary currently in working state is blocked.

[0023] In some embodiments, the anti-blocking method of the refrigeration system further includes a method for determining whether a capillary tube in a working state is blocked, which includes the following steps:

[0024] Detecting the second outlet temperature of the throttling assembly by a third temperature detecting member;

[0025] When the second outlet temperature is lower than that under normal operating conditions and the cooling rate is greater than or equal to a second preset value, or when the second outlet temperature is lower than the second preset temperature value, it is determined that the capillary currently in operation is clogged.

[0026] In some embodiments, the method for preventing blockage of a refrigeration system further comprises the steps of:

[0027] The clogged capillary is heated by the heating element until a preset heating time is reached or the temperature in the capillary reaches a preset heating temperature.

[0028] Based on the above technical solution, the present disclosure has at least the following beneficial effects:

[0029] In some embodiments, the refrigeration system includes two capillaries connected in parallel, the two capillaries are of the same length, and one of them is in working state. When the capillary in working state is blocked, the other capillary is switched to working state to avoid the influence of oil blockage or ice blockage of the capillary on the refrigeration system, and improve the adaptability of the capillary to the whole operation process of the refrigeration system; a whole section of the capillary is set as two sections of capillaries with different inner diameters connected in series. Among them, the first section has a slightly smaller diameter and is the inlet pipe, and the second section has a slightly larger diameter and is the outlet pipe. The refrigerant throttles in the capillary to reduce pressure and temperature. The outlet temperature of the capillary is much lower than the inlet temperature. When the refrigerant throttles to the end of the capillary, the temperature drops to a very low level. At this time, the lubricating oil will solidify. The blockage mainly occurs in the second half of the capillary. Therefore, using a slightly thicker section as the outlet pipe can make the flow of the lubricating oil smoother, which is conducive to the flow of the lubricating oil back to the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of the present application. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation on the present disclosure. In the drawings:

[0031] Figure 1 A schematic diagram of a refrigeration system provided according to some embodiments of the present disclosure;

[0032] Figure 2 A schematic diagram of a capillary tube and a heating element provided according to some embodiments of the present disclosure;

[0033] Figure 3 A schematic flow chart of a method for preventing blockage in a refrigeration system according to some embodiments of the present disclosure.

[0034] The reference numerals in the accompanying drawings are described as follows:

[0035] 11-first compressor; 12-second compressor;

[0036] 21-first heat exchanger; 22-second heat exchanger; 23-third heat exchanger;

[0037] 3-throttling assembly; 31-capillary tube; 311-first pipe section; 312-second pipe section;

[0038] 4- Heating element;

[0039] 5-Throttling element;

[0040] 6- Controller;

[0041] 7-Control valve;

[0042] 81-first temperature detection element; 82-second temperature detection element; 83-third temperature detection element;

[0043] 91-a first drying filter; 92-a second drying filter;

[0044] 10-Oil separator.

[0045] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0046] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0047] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0048] In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other device without an intermediate device, or may not be directly connected to the other device but have an intermediate device.

[0049] All terms (including technical terms or scientific terms) used in the present disclosure have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0050] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0051] Figure 1 Schematic diagram of the structure of some embodiments of the refrigeration system according to the present disclosure. Figure 1 In some embodiments, the refrigeration system includes a first compressor 11, a first heat exchanger 21, a throttling assembly 3, and a second heat exchanger 22. Along the flow direction of the refrigerant, the first compressor 11, the first heat exchanger 21, the throttling assembly 3, the second heat exchanger 22 and the first compressor 11 are sequentially connected, wherein the throttling assembly 3 includes two capillary tubes 31 connected in parallel, the two capillary tubes 31 have the same length, and the two capillary tubes 31 are configured to be in a working state at one end.

[0052] The refrigeration system provided by the embodiment of the present disclosure includes two capillaries 31 connected in parallel. The two capillaries 31 have the same length and are configured to select one to be in a working state. When the capillary 31 in the working state is blocked, the other capillary 31 is switched to be in a working state, so as to avoid the influence of oil blockage or ice blockage of the capillary on the refrigeration system and improve the adaptability of the capillary to the whole operation process of the refrigeration system. In addition, the refrigeration system provided by the embodiment of the present disclosure only adds one capillary compared to the traditional refrigeration system, has a simple structure, convenient anti-blocking operation, and does not increase the cost much, but reduces the influence of oil blockage on the system to a minimum, or even no influence.

[0053] In some embodiments, the second heat exchanger 22 is configured to perform heat exchange and cooling for a space that requires refrigeration. By detecting the temperature of the space that requires refrigeration, it is determined whether the capillary tube 31 is blocked, and switching between two capillaries of equal length is achieved. Therefore, the impact of the capillary tube on the reliable and stable operation of the refrigeration system can be reduced.

[0054] refer to Figure 2 In some embodiments, each of the two capillaries 31 includes a first pipe segment 311 and a second pipe segment 312 connected in series, the first pipe segment 311 is connected to the first heat exchanger 21, the second pipe segment 312 is connected to the second heat exchanger 22, and the diameter of the first pipe segment 311 is smaller than the diameter of the second pipe segment 312.

[0055] In order to effectively alleviate the problem of capillary blockage (oil blockage and ice blockage), a whole section of capillary tube is set to be two sections of capillaries with different inner diameters connected in series. Among them, the first section 311 has a slightly smaller diameter and is the inlet tube, and the second section 312 has a slightly larger diameter and is the outlet tube. The refrigerant is throttled to reduce pressure and temperature in the capillary tube 31. The outlet temperature of the capillary tube 31 is much lower than the inlet temperature. When the refrigerant is throttled to the end of the capillary tube 31, the temperature drops to a very low level. At this time, the lubricating oil will solidify. The blockage mainly occurs in the second half of the capillary tube. Therefore, using a slightly thicker section as the outlet tube can make the flow of the lubricating oil smoother, which is conducive to the flow of the lubricating oil back to the compressor.

[0056] In some embodiments, the structures and dimensions of the two capillaries 31 are the same.

[0057] In some embodiments, the refrigeration system further includes two heating elements 4 , and the two heating elements 4 are configured to heat two capillary tubes 31 in a one-to-one correspondence. That is, each capillary tube 31 is heated by a corresponding heating element 4 .

[0058] The first compressor 11 is turned on, and the refrigeration system is running. When the capillary tube 31 currently in working state is blocked, another capillary tube 31 is switched to working state, and the heating element 4 is turned on to heat the blocked capillary tube 31. When the tube temperature of the blocked capillary tube 31 reaches the preset heating temperature or the heating time reaches the preset heating time, the heating element 4 stops heating, and the blocked capillary tube 31 is unobstructed and ready for use. When the capillary tube 31 in working state is blocked, it is switched for use again. This cycle is repeated to realize the switching between two parallel capillary tubes 31 of equal length in the refrigeration system.

[0059] In some embodiments, the two heating elements 4 extend in a spiral manner, and the two heating elements 4 are respectively and correspondingly disposed in the cavities formed by the spirals of the two capillaries 31. In other words, a heating element 4 is disposed in the cavity formed by the spiral extension of each capillary 31.

[0060] The heating element 4 comprises a strip-shaped heating portion, and the strip-shaped heating portion is arranged in a cavity formed by the spiral extension of the heating element 4 .

[0061] The capillary 31 is spirally wound to form a disk shape, and the heating element 4 passes through the center of the disk-shaped capillary. The heating element 4 is energized to heat the clogged capillary 31 .

[0062] In some embodiments, the refrigeration system further includes a controller 6 , which is electrically connected to the two heating elements 4 , and the controller 6 is configured to control the heating temperature or heating time of the capillary tube 31 by the heating elements 4 .

[0063] When one of the capillaries 31 is blocked, the other capillary 31 is switched to a working state, and the blocked capillary 31 is heated by the heating element 4, which will not affect the stable operation of the refrigeration system. The heating time or heating temperature is controlled by the controller 6, which can prevent the operation of the capillary 31 from being affected by too long heating time or too high heating temperature, and can also prevent the heating time from being too short or the heating temperature from being too low, which is not conducive to unblocking the blocked capillary 31. Therefore, the influence of capillary heating on the stable operation of the refrigeration system can be reduced, and the system reliability can be improved.

[0064] In some embodiments, the refrigeration system also includes a controller 6 and two control valves 7. The two control valves 7 are configured to control the two capillaries 31 to be in a working state or a non-working state respectively. The controller 6 is electrically connected to the two control valves 7. The controller 6 is configured to control one of the two control valves 7 to open so that the capillary 31 corresponding to the opened control valve 7 is in a working state.

[0065] One of the control valves 7 is disposed on the pipeline where one of the capillary tubes 31 is located, and the other control valve 7 is disposed on the pipeline where the other capillary tube 31 is located.

[0066] A control valve 7 controls the on-off of a pipeline where a capillary tube 31 is located. When the control valve 7 is opened, the pipeline where the capillary tube 31 corresponding to the control valve 7 is located is connected, and the capillary tube 31 is in a working state. When the control valve 7 is closed, the pipeline where the capillary tube 31 corresponding to the control valve 7 is located is disconnected, and the capillary tube 31 is in a non-working state.

[0067] In some embodiments, the refrigeration system also includes a first temperature detection component 81 and a second temperature detection component 82 electrically connected to the controller 6, the first temperature detection component 81 is configured to detect the first outlet temperature of the second heat exchanger 22, and the second temperature detection component 82 is configured to detect the temperature in the space where the second heat exchanger 22 is to perform heat exchange (cooling), the controller 6 is configured to receive temperature signals detected by the first temperature detection component 81 and the second temperature detection component 82, and when the first outlet temperature is greater than the temperature in the space, and the first outlet temperature continues to rise, and the heating rate is greater than or equal to a first preset value, or when the first outlet temperature is higher than the first preset temperature value, the control valve 7 that is currently in an open state is controlled to be closed, and the control valve 7 that is in a closed state is controlled to be opened.

[0068] By using the first outlet temperature of the second heat exchanger 22 and the relationship between the first outlet temperature and the temperature in the space where the second heat exchanger 22 is to perform heat exchange, it is determined whether the capillary tube 31 currently in operation is blocked, and the determination result is relatively accurate.

[0069] The first temperature detecting element 81 is configured to detect a first outlet temperature of the second heat exchanger 22 . The first temperature detecting element 81 may be disposed at the outlet of the second heat exchanger 22 .

[0070] In some embodiments, the refrigeration system also includes a third temperature detection component 83 electrically connected to the controller 6, and the third temperature detection component 83 is configured to detect the second outlet temperature of the throttling assembly 3. When the second outlet temperature is lower than that under normal operating conditions and the cooling rate is greater than or equal to a second preset value, or when the second outlet temperature is lower than the second preset temperature value, the control valve 7 that is currently in an open state is controlled to be closed, and the control valve 7 that is in a closed state is controlled to be opened.

[0071] The second outlet temperature of the throttling assembly 3 can be obtained by detecting the outlet temperature of the working capillary tube 31. The third temperature detection member 83 can be arranged at the outlet of the throttling assembly 3, for example, a third temperature detection member 83 is arranged at the outlet of the two capillaries 31 respectively.

[0072] In some embodiments, the refrigeration system further includes an oil separator 10, which is disposed on the pipeline between the first compressor 11 and the first heat exchanger 21, and the oil separator 10 is connected to the first compressor 11 through an oil return pipeline. The oil separator 10 is used to separate the lubricating oil in the refrigerant, and return the separated lubricating oil to the first compressor 11 through the oil return pipeline to reduce the oil content in the refrigerant.

[0073] In some embodiments, the refrigeration system further includes a first drying filter 91, which is disposed on a pipeline between the first heat exchanger 21 and the throttling assembly 3. The first drying filter 91 is used to absorb moisture in the refrigerant.

[0074] In some embodiments, the refrigeration system further includes a second compressor 12, a third heat exchanger 23 and a throttling device 5. Along the flow direction of the refrigerant, the second compressor 12, the third heat exchanger 23, the throttling device 5, the first heat exchanger 21 and the second compressor 12 are connected in sequence.

[0075] The refrigerants in the first compressor 11 and the second compressor 12 both pass through the first heat exchanger 21. The refrigerant in the second compressor 12 absorbs heat and evaporates when passing through the first heat exchanger 21, and the refrigerant in the first compressor 11 releases heat and condenses when passing through the first heat exchanger 21. The refrigerant provided by the second compressor 12 is cooled in the first heat exchanger 21 for the refrigerant provided by the first compressor 11. Compared with cooling in a normal environment, the temperature of the refrigerant provided by the first compressor 11 can be reduced to an extremely low temperature, so that after the refrigerant provided by the first compressor 11 is cooled in the first heat exchanger 21, it is further cooled by the throttling component 3, and heat is exchanged with the space that needs to be cooled in the second heat exchanger 22, so that the space that needs to be cooled can reach an extremely low temperature environment to meet the use requirements.

[0076] The throttling device 5 in the refrigeration circulation pipeline where the second compressor 12 is located can also adopt a capillary tube. The probability of blockage of the throttling device 5 is small. This is because in the refrigeration circulation pipeline where the second compressor 12 is located, the temperature of the refrigerant after throttling by the throttling device 5 is about -40°C, and the pour point temperature of the lubricating oil is about -50°C. Therefore, the probability of oil blockage in the refrigeration circulation pipeline where the second compressor 12 is located is extremely small.

[0077] The refrigeration circulation pipeline where the first compressor 11 is located shares the first heat exchanger 21 with the refrigeration circulation pipeline where the second compressor 12 is located. Therefore, the temperature of the refrigerant in the refrigeration circulation pipeline where the first compressor 11 is located after passing through the first heat exchanger 21 can be reduced to an extremely low temperature. The temperature of the refrigerant passing through the throttling component 3 can reach -80°C, which is much lower than the pour point of the lubricating oil. Therefore, the throttling component 3 is prone to oil blockage or ice blockage.

[0078] The throttling assembly 3 includes two capillaries 31 of equal length connected in parallel. When one of the capillaries 31 is blocked, the other capillary 31 is switched to a working state, and the heating element 4 is turned on to heat the blocked capillary 31. When the temperature of the blocked capillary 31 reaches a preset heating temperature or the heating time reaches a preset heating time, the heating element 4 stops heating, and the blocked capillary 31 is unblocked at this time, and the capillary 31 in the working state is switched back to use after being blocked. In this way, the switching between the two capillary tubes 31 of equal length connected in parallel in the refrigeration system is realized, and the influence of oil blockage or ice blockage of the capillary 31 on the refrigeration system is avoided.

[0079] In some embodiments, the refrigeration system further includes a second drying filter 92, which is disposed on the pipeline between the third heat exchanger 23 and the throttling element 5. The second drying filter 92 is used to absorb moisture in the refrigerant.

[0080] Some embodiments further provide a method for preventing blocking of the refrigeration system, which comprises the following steps:

[0081] The first compressor 11 is running, so that one of the two capillary tubes 31 connected in parallel is in working state;

[0082] When a capillary tube 31 in working state is clogged, another capillary tube 31 is switched to be in working state.

[0083] The refrigeration system provided by the embodiment of the present disclosure includes two capillaries 31 connected in parallel, the two capillaries 31 have the same length, one of the capillaries 31 is in working state, and when the capillary 31 in working state is blocked, the other capillary 31 is switched to working state, so as to avoid the influence of oil blockage or ice blockage of the capillary 31 on the refrigeration system, and improve the adaptability of the capillary 31 to the whole operation process of the refrigeration system. The refrigeration system provided by the embodiment of the present disclosure has a simple structure, convenient anti-blocking operation, and does not increase the cost much, but reduces the influence of oil blockage on the system to a minimum, or even no influence.

[0084] In some embodiments, the anti-blocking method of the refrigeration system further includes a method for determining whether the capillary tube 31 in the working state is blocked, which includes the following steps:

[0085] Detecting a first outlet temperature of the second heat exchanger 22 by means of a first temperature detection member 81;

[0086] The temperature in the space where the second heat exchanger 22 is to perform heat exchange is detected by the second temperature detection member 82;

[0087] When the first outlet temperature is greater than the temperature in the space, and the first outlet temperature continues to rise, and the heating rate is greater than or equal to the first preset value, or the first outlet temperature is higher than the first preset temperature value, it is determined that the capillary 31 currently in working state is blocked.

[0088] In some embodiments, the anti-blocking method of the refrigeration system further includes a method for determining whether the capillary tube 31 in the working state is blocked, which includes the following steps:

[0089] Detecting the second outlet temperature of the throttling assembly 3 by the third temperature detecting member 83;

[0090] When the second outlet temperature is lower than that in normal working conditions and the cooling rate is greater than or equal to the second preset value, or when the second outlet temperature is lower than the second preset temperature value, it is determined that the capillary tube 31 currently in working state is clogged.

[0091] In some embodiments, the method for preventing blockage of a refrigeration system further comprises the steps of:

[0092] The clogged capillary 31 is heated by the heating element 4 until a preset heating time is reached or the temperature in the capillary 31 reaches a preset heating temperature.

[0093] In order to prevent oil and ice blockage of the capillary tube from affecting the normal operation of the refrigeration system, the embodiment of the present disclosure judges whether the capillary tube is blocked based on the first outlet temperature of the second heat exchanger 22 or the second outlet temperature of the throttling component 3, thereby realizing the switching of the refrigeration system between two capillaries of equal length and the heating of the blocked capillary tube.

[0094] Some specific embodiments of the refrigeration system are described in detail below.

[0095] refer to Figure 1 , the refrigeration system includes high temperature stage components and low temperature stage components.

[0096] The high temperature stage assembly includes the second compressor 12, the third heat exchanger 23, the second filter drier 92 and the throttling device 5. The third heat exchanger 23 serves as a condenser. Along the flow direction of the refrigerant, the second compressor 12, the third heat exchanger 23, the throttling device 5, the first heat exchanger 21 and the second compressor 12 are connected in sequence.

[0097] The low temperature stage assembly includes a first compressor 11, an oil separator 10, a first filter dryer 91, a throttling assembly 3 (two capillaries 31 connected in parallel), a second heat exchanger 22, two heating elements 4 and two control valves 7. Along the flow direction of the refrigerant, the first compressor 11, the first heat exchanger 21, the throttling assembly 3, the second heat exchanger 22 and the first compressor 11 are connected in sequence. The second heat exchanger 22 serves as an evaporator.

[0098] The high temperature stage assembly and the low temperature stage assembly share the first heat exchanger 21. The first heat exchanger 21 serves as an evaporator in the high temperature stage assembly and as a condenser in the low temperature stage assembly.

[0099] The lubricating oil accumulated in the oil separator 10 flows into the first compressor 11 through the oil return pipeline.

[0100] The two parallel capillaries 31 in the low temperature stage assembly include a first capillary and a second capillary, the two control valves 7 include a first control valve and a second control valve, and the two heating elements 4 include a first heating element and a second heating element. The first control valve controls the first capillary to be in a working state or a non-working state. The second control valve controls the second capillary to be in a working state or a non-working state. The first heating element is used to heat the first capillary. The second heating element is used to heat the second capillary.

[0101] refer to Figure 3, the first compressor 11 and the second compressor 12 are turned on (including two stages of starting and stopping and starting from ambient temperature to pull the temperature), the refrigeration system is running, the first capillary is in working state, and the second capillary is in non-working state. The first temperature detection component 81 is used to detect the first outlet temperature of the second heat exchanger 22, and the second temperature detection component 82 is used to detect the temperature in the space where the second heat exchanger 22 is to exchange heat. When the first outlet temperature is higher than the temperature in the space, and the first outlet temperature shows a trend of continuous increase, the heating rate is greater than or equal to the first preset value, or the first outlet temperature is higher than the first preset temperature value, it is judged that the first capillary is blocked. Alternatively, the second outlet temperature of the throttling component 3 is detected by the third temperature detection component 83; when the second outlet temperature is lower than that under normal conditions, and the cooling rate is greater than or equal to the second preset value, or the second outlet temperature is lower than the second preset temperature value, it is judged that the first capillary is blocked. At this time, the second control valve is used to switch the second capillary tube to be connected to the pipeline and is in a working state, the first capillary tube is disconnected from the pipeline and is in a non-working state, and the first heating element is turned on to heat the blocked first capillary tube. When the tube temperature of the first capillary tube reaches the preset heating temperature T (first capillary tube temperature ≥ T) or the electric heating time reaches the preset heating time t (heating time ≥ t), the first heating element is powered off and the electric heating exits.

[0102] Similarly, if it is determined that the second capillary is blocked, the first control valve controls the first capillary to be connected to the pipeline in a working state, and the second control valve controls the second capillary to be in a non-working state. The second heating element is turned on to heat the blocked second capillary, and when the tube temperature of the second capillary reaches a preset heating temperature T or the electric heating time reaches a preset heating time t, the second heating element is powered off and the electric heating is exited.

[0103] This cycle is used to switch between two parallel capillaries of equal length in the refrigeration system.

[0104] Some embodiments further provide a medical low-temperature preservation box, which includes a box body and a refrigeration system in any of the above embodiments.

[0105] A storage space for accommodating articles is formed in the box. The second heat exchanger 22 is configured to cool the storage space.

[0106] In some embodiments, the temperature of the storage space is required to be -80°C to -90°C.

[0107] In some embodiments, the refrigeration system further includes a second temperature detection member 82, which is used to detect the temperature in the space where the second heat exchanger 22 is to perform heat exchange. In this embodiment, the space where the second heat exchanger 22 is to perform heat exchange is a storage space for accommodating articles formed in the box of the medical low-temperature preservation box. The second temperature detection member 82 is used to detect the temperature in the storage space.

[0108] In some embodiments, the refrigeration system also includes a second compressor 12, a third heat exchanger 23 and a throttling device 5 arranged outside the box body. Along the flow direction of the refrigerant, the second compressor 12, the third heat exchanger 23, the throttling device 5, the first heat exchanger 21 and the second compressor 12 are connected in sequence.

[0109] The second heat exchanger 22 is used to cool down the storage space for containing articles formed in the medical low-temperature preservation box. The first compressor 11, the first heat exchanger 21, and the throttling component 3 can be arranged in the box and located outside the storage space.

[0110] The second compressor 12, the third heat exchanger 23 and the throttling element 5 may be arranged outside the casing.

[0111] Based on the above-mentioned embodiments of the present disclosure, in the absence of explicit negation or conflict, the technical features of one embodiment may be beneficially combined with one or more other embodiments.

[0112] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A refrigeration system, characterized in that: The invention comprises a first compressor (11), a first heat exchanger (21), a throttling assembly (3) and a second heat exchanger (22); along the flow direction of the refrigerant, the first compressor (11), the first heat exchanger (21), the throttling assembly (3), the second heat exchanger (22) and the first compressor (11) are connected in sequence, wherein the throttling assembly (3) comprises two capillaries (31) connected in parallel, the two capillaries (31) have the same length, and the two capillaries (31) are configured to be in a working state at one end; each of the two capillaries (31) comprises a first pipe section (311) and a second pipe section (312) connected in series, the first pipe section (311) being connected to the first heat exchanger (21), the second pipe section (312) being connected to the second heat exchanger (22), and the pipe diameter of the first pipe section (311) being smaller than the pipe diameter of the second pipe section (312); It also comprises two heating elements (4), the two heating elements (4) being configured to heat the two capillaries (31) in a one-to-one correspondence; It also comprises a controller (6), the controller (6) being electrically connected to the two heating elements (4), the controller (6) being configured to control the heating temperature or heating time of the capillary (31) by the heating element (4); The controller (6) is configured to, when the first capillary tube of the two capillaries (31) is blocked, control the second capillary tube of the two capillaries (31) to be in a working state, and turn on the heating element (4) to heat the first capillary tube; when the tube temperature of the first capillary tube reaches a preset heating temperature or the heating time reaches a preset heating time, control the heating element (4) to stop heating so that the first capillary tube is unobstructed; and when the second capillary tube is blocked, control the first capillary tube to be in a working state again; The controller (6) further comprises a first temperature detection component (81) and a second temperature detection component (82) electrically connected to the controller (6), wherein the first temperature detection component (81) is configured to detect a first outlet temperature of the second heat exchanger (22), and the second temperature detection component (82) is configured to detect a temperature in a space where the second heat exchanger (22) is to perform heat exchange, and the controller (6) is configured to receive temperature signals detected by the first temperature detection component (81) and the second temperature detection component (82), and when the first outlet temperature is greater than the temperature in the space, and the first outlet temperature continues to rise, and the heating rate is greater than or equal to a first preset value, it is determined that the capillary tube (31) currently in the working state is blocked.

2. The refrigeration system according to claim 1, characterized in that: The two heating elements (4) extend in a spiral, and the two heating elements (4) are respectively arranged in a one-to-one correspondence in the cavities formed by the two capillaries (31) in a spiral.

3. The refrigeration system according to claim 1, characterized in that: The invention also comprises two control valves (7), wherein the two control valves (7) are configured to control the two capillaries (31) to be in a working state or a non-working state in a one-to-one correspondence, respectively; the controller (6) is electrically connected to the two control valves (7), and the controller (6) is configured to control one of the two control valves (7) to be opened, so that the capillary (31) corresponding to the opened control valve (7) is in a working state.

4. The refrigeration system according to claim 3, characterized in that: The device further comprises a third temperature detection component (83) electrically connected to the controller (6), wherein the third temperature detection component (83) is configured to detect a second outlet temperature of the throttling component (3), and when the second outlet temperature is lower than that under normal operating conditions, and the temperature reduction rate is greater than or equal to a second preset value, or when the second outlet temperature is lower than the second preset temperature value, the control valve (7) currently in an open state is controlled to be closed, and the control valve (7) currently in a closed state is controlled to be opened.

5. The refrigeration system according to any one of claims 1 to 4, characterized in that: It also includes a second compressor (12), a third heat exchanger (23) and a throttling device (5); along the flow direction of the refrigerant, the second compressor (12), the third heat exchanger (23), the throttling device (5), the first heat exchanger (21) and the second compressor (12) are connected in sequence.

6. A medical low temperature storage box, characterized in that: include: A box body, in which a storage space for accommodating items is formed; as well as The refrigeration system according to any one of claims 1 to 5, wherein the second heat exchanger (22) is configured to cool the storage space.

7. The medical low temperature storage box according to claim 6, characterized in that: It also includes a second compressor (12), a third heat exchanger (23) and a throttling device (5) arranged outside the box body. Along the flow direction of the refrigerant, the second compressor (12), the third heat exchanger (23), the throttling device (5), the first heat exchanger (21) and the second compressor (12) are connected in sequence.

8. A method for preventing blocking of a refrigeration system according to any one of claims 1 to 5, comprising the following steps: The first compressor (11) operates so that one of the two capillary tubes (31) connected in parallel is in a working state; When a capillary tube (31) in a working state is clogged, another capillary tube (31) is switched to a working state.

9. The anti-blocking method for a refrigeration system according to claim 8, further comprising a method for determining whether a capillary tube (31) in a working state is blocked, comprising the following steps: detecting a first outlet temperature of the second heat exchanger (22) by means of a first temperature detecting element (81); detecting the temperature of the space in which the second heat exchanger (22) is to perform heat exchange by means of a second temperature detection element (82); When the first outlet temperature is greater than the temperature in the space, and the first outlet temperature continues to rise, and the heating rate is greater than or equal to a first preset value, or when the first outlet temperature is higher than the first preset temperature value, it is determined that the capillary tube (31) currently in operation is clogged.

10. The anti-blocking method for a refrigeration system according to claim 8, further comprising a method for determining whether a capillary tube (31) in a working state is blocked, comprising the following steps: detecting a second outlet temperature of the throttling assembly (3) by means of a third temperature detecting member (83); When the second outlet temperature is lower than that under normal working conditions and the cooling rate is greater than or equal to a second preset value, or when the second outlet temperature is lower than the second preset temperature value, it is determined that the capillary tube (31) currently in operation is clogged.

11. The anti-blocking method for a refrigeration system according to any one of claims 8 to 10, further comprising the steps of: The clogged capillary tube (31) is heated by the heating element (4) until a preset heating time is reached or the temperature in the capillary tube (31) reaches a preset heating temperature.

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