Working medium purification device and refrigeration system

Abstract

A working medium purification device and a refrigeration system. The working medium purification device is configured to purify working media of refrigeration apparatuses (9), and comprises: a cold-trap mechanism (1), which comprises a cold-trap body (12) mounted on a cold head (3) of a first refrigerating machine and forming heat conduction with the cold head (3), so as to be cooled by the cold head (3) to a first temperature configured to adsorb impurities, and a vacuum cover (11) covering the outer side of the cold-trap body (12), wherein a vacuum cavity configured to be evacuated to a vacuum state is defined inside the vacuum cover (11), such that the cold-trap body (12) is thermally isolated from an external environment; a piping mechanism (5), which comprises a first branch (51) configured to connect the cold-trap body (12) in parallel to circulation lines (4) of the refrigeration apparatuses (9) to be subjected to purification and configured to selectively communicate with one of the circulation lines (4); and a desorption mechanism, which is configured to, in response to the cut-off state of the first branch (51), heat the cold-trap body (12) to a second temperature configured to desorb impurities, and to extract the impurities inside the cold-trap body (12).

Description

Working medium purification device and refrigeration system TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of refrigeration equipment, and particularly relates to a working medium purification device and a refrigeration system. BACKGROUND

[0002] A refrigeration machine mainly transfers heat through a working medium in a refrigeration cycle to achieve cooling. In the use process of a refrigeration machine (such as a compression refrigeration machine, an absorption refrigeration machine, a Stirling refrigeration machine, a pulse tube refrigeration machine, a magnetic refrigeration machine and a low-temperature refrigeration machine), a cold trap is often configured to remove part of impurities (such as oil vapor, water vapor and impurity gas) in a sealed circulation system.

[0003] Taking the removal of impurities of a dilution refrigerator (one kind of low-temperature refrigerator) as an example, a cold trap arranged in a sealed circulation system using helium 3 as a working medium needs to use liquid nitrogen as a cooling medium, so that the cold trap is maintained in an adsorption state at a low temperature (77K). In order to maintain the above low-temperature condition, the cold trap and the liquid nitrogen need to be stored in a dewar, which not only needs to be regularly supplemented with liquid nitrogen, but also needs to occupy a large volume. Moreover, in the actual operation process, the cold trap also needs to be cleaned regularly in order to maintain the adsorption performance of the cold trap.

[0004] When the cold trap is cleaned, in order to make the impurities adsorbed by the cold trap desorb, the cold trap needs to be moved out of the liquid nitrogen environment and heated to room temperature. Therefore, online cleaning cannot be performed in the dewar. In addition, in the process of taking out the cold trap from the dewar, liquid nitrogen is also lost and has a certain risk.

[0005] Therefore, how to provide a working medium purification device and a refrigeration system which occupy a small space and can be cleaned online has become a technical problem to be solved.

[0006] SUMMARY

[0007] In order to solve at least one of the above and other aspects in the prior art, the present disclosure provides a working medium purification device and a refrigeration system.

[0008] Embodiments of the present disclosure provide a working medium purification device configured to purify working medium of a refrigeration device, comprising: a cold trap mechanism, comprising: a cold trap body, mounted on a cold head of a first refrigeration machine, and in thermal conduction with the cold head to be cooled by the cold head to a first temperature configured to adsorb impurities; a vacuum cover, covering the outside of the cold trap body, and defining a vacuum cavity configured to be extracted to a vacuum state in the vacuum cover, so that the cold trap body is thermally insulated from the external environment; a pipeline mechanism, comprising: a first branch, configured to be connected in parallel with the cold trap body to the circulating pipeline of the refrigeration device to be purified, and constructed to be selectively connected with the circulating pipeline; and a desorption mechanism, constructed to heat the cold trap body to a second temperature configured to desorb impurities in response to the cutoff state of the first branch, and extract the impurities in the cold trap body.

[0009] According to embodiments of the present disclosure, the desorption mechanism comprises: a heating assembly configured to heat the cold trap body to the second temperature; and a first vacuum pump in communication with the cold trap body, configured to extract the impurities desorbed from the cold trap body.

[0010] According to embodiments of the present disclosure, the heating assembly is arranged in the cold head; and the desorption mechanism further comprises a temperature acquisition assembly in communication connection with the heating assembly, configured to acquire the temperature of the cold head and / or the cold trap body.

[0011] According to embodiments of the present disclosure, the pipeline mechanism further comprises a second branch arranged between the cold trap body and the circulating pipeline, and the second branch is connected with the cold trap body and the circulating pipeline in response to the cutoff state of the first branch, so that the working medium remaining in the cold trap body flows back to the circulating pipeline.

[0012] According to embodiments of the present disclosure, the cold trap mechanism further comprises an air inlet pipe and an air outlet pipe, the air inlet pipe serves as an air inlet end of the cold trap body, and the air outlet pipe serves as an air outlet end of the cold trap body; wherein the air inlet pipe and the air outlet pipe are arranged side by side and in thermal conduction.

[0013] According to embodiments of the present disclosure, the cold trap body comprises a first part close to the cold head and a second part away from the cold head; wherein the first part and the second part are made of different materials, and the thermal conductivity of the first part is higher than that of the second part.

[0014] According to embodiments of the present disclosure, the cold trap body is provided with an adsorption material, and the adsorption material is filled at least in the first part.

[0015] Embodiments of the present disclosure also provide a refrigeration system, comprising: at least one refrigeration device to be purified; at least one working medium purification device, a first branch of the working medium purification device being connected in parallel with a circulation pipeline of each of the refrigeration devices and being configured to be selectively and alternatively conducted with the circulation pipeline; and a second vacuum pump being connected in communication with a vacuum cover of the working medium purification device and being configured to extract a vacuum cavity to a vacuum state; wherein the working medium purification device is configured to adsorb impurities in working medium in response to a conducting state of the first branch, and is configured to desorb the impurities in a cold trap main body of the working medium purification device in response to a cut-off state of the first branch.

[0016] According to embodiments of the present disclosure, the refrigeration system comprises a plurality of refrigeration devices connected in parallel.

[0017] According to embodiments of the present disclosure, the refrigeration system comprises at least two working medium purification devices, the two working medium purification devices being redundant and being alternatively conducted with the refrigeration devices.

[0018] According to the working medium purification device and the refrigeration system provided by the present disclosure, the cold trap main body is installed on the cold head of the first refrigeration machine, so that the cold head replaces the liquid nitrogen in the prior art as a cold source, which can not only reduce the volume of the device, but also prevent the leakage of liquid nitrogen and avoid the replenishment of liquid nitrogen. The first branch of the pipeline mechanism connects the cold trap main body in parallel with the circulation pipeline of the refrigeration device, so that the working medium can be switched between the circulation pipeline and the cold trap main body. The first branch in the cut-off state makes the working medium pass through the circulation pipeline and isolates the cold trap main body from the working medium, so as to clean the impurities adsorbed by the cold trap main body on-line through the desorption mechanism. BRIEF DESCRIPTION OF DRAWINGS

[0019] FIG. 1 is a perspective view of a working medium purification device according to an illustrative embodiment of the present disclosure;

[0020] FIG. 2 is a perspective view of the working medium purification device shown in FIG. 1, showing a cold trap main body;

[0021] FIG. 3 is a gas circuit diagram of the working medium purification device shown in FIG. 1;

[0022] FIG. 4 is a gas circuit diagram of another illustrative embodiment of the working medium purification device shown in FIG. 1;

[0023] FIG. 5 is a partial enlarged view of the working medium purification device shown in FIG. 1, showing an adapter ring;

[0024] FIG. 6 is a module schematic diagram of a refrigeration system according to an illustrative embodiment of the present disclosure; and

[0025] FIG. 7 is a module schematic diagram of a refrigeration system according to another illustrative embodiment of the present disclosure, showing an embodiment with two working medium purification devices.

[0026] In the drawings, the meaning of the reference signs is as follows: 1, cold trap mechanism; 11, vacuum cover; 12, cold trap main body; 121, first part; 122, second part; 13, gas inlet pipe; 14, gas outlet pipe; 2, connecting mechanism; 21, first flange; 22, sleeve; 23, second flange; 24, adapter ring; 3, cold head; 4, circulation pipeline; 5, pipeline mechanism; 51, first branch; 52, second branch; 53, third branch; 6, first vacuum pump; 7, gas extraction pipeline; 8, second vacuum pump; 9, refrigeration equipment; 91, first refrigeration equipment; 92, second refrigeration equipment; 93, third refrigeration equipment; and 94, fourth refrigeration equipment. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to specific embodiments and with reference to the drawings.

[0028] The terms used herein are merely used to describe specific embodiments, and are not intended to limit the present disclosure. The terms "include", "comprise" and the like used herein indicate the presence of the described features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0029] All terms used herein, including technical and scientific terms, have the meanings commonly understood by a person skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted in a manner consistent with the context of the present specification, and should not be interpreted in an idealized or overly formal manner.

[0030] In the case of using expressions similar to "at least one of A, B, and C, etc.", it should be generally interpreted that the meaning of the expression is at least one of the items selected from the group consisting of A, B, and C, for example, in the case of a system having at least one of A, B, and C, it should be construed that the system includes but is not limited to a system having A alone, a system having B alone, a system having C alone, a system having both A and B, a system having both A and C, a system having both B and C, and / or a system having A, B, and C together, etc. In the case of using expressions similar to "at least one of A, B, or C, etc.", it should be generally interpreted that the meaning of the expression is at least one of the items selected from the group consisting of A, B, and C, for example, in the case of a system having at least one of A, B, and C, it should be construed that the system includes but is not limited to a system having A alone, a system having B alone, a system having C alone, a system having both A and B, a system having both A and C, a system having both B and C, and / or a system having A, B, and C together, etc.

[0031] A dilution refrigerator is an example of a dilution refrigerator, which is a millikelvin-level refrigeration device using a mixture of helium-3 and helium-4 to perform a dilution refrigeration cycle. At a temperature of 0.86 K (theoretical upper limit), helium-3 and helium-4 are separated into two phases, in which the concentrated phase mainly includes helium-3, and the dilute phase mainly includes a mixture of helium-3 and helium-4. In the dilution refrigeration process, the pump group is configured to extract helium-3 in the dilute phase to the external environment for heat exchange and return to the concentrated phase.

[0032] During the cycle of the working medium of the dilution refrigerator, some impurities such as water vapor, oil vapor, and gas molecules that are not easy to condense at room temperature (such as hydrogen, nitrogen, and oxygen) are mixed. These impurities do not participate in the main heat absorption process (i.e., helium-3 enters the dilute phase) during the circulation of the working medium in the sealed circulation system (such as the circulation pipeline), and thus affect the performance and cooling capacity of the dilution refrigerator, resulting in the dilution refrigerator being unable to cool to the required extremely low temperature (such as millikelvin). Even if the gas path is blocked due to the condensation or solidification of impurities, the dilution refrigerator cannot work normally.

[0033] Currently, the cold trap mechanism is mainly arranged in the Dewar. When cleaning the cold trap body sealed in liquid nitrogen, the sealing state of the Dewar needs to be released (at this time, the liquid nitrogen in the Dewar will vaporize and leak until it is emptied, so this process cannot be carried out in a sealed indoor environment and will cause a large amount of liquid nitrogen consumption), and the cold trap body is removed from the Dewar to the external environment. After the cold trap body is heated to room temperature, it is cleaned by desorption. After cleaning is completed, it needs to be reinstalled in the Dewar and the corresponding liquid nitrogen is supplemented to recool until the appropriate adsorption temperature is reached. Therefore, the above process is complex and time-consuming (up to several hours), and since the cold trap body needs to be removed, the desorption process of the cold trap body cannot be cleaned online.

[0034] On this basis, how to provide a working medium purification device and a refrigeration system with small occupied space and online cleaning becomes a technical problem to be solved.

[0035] FIG. 1 is a perspective view of a working medium purification device according to an illustrative embodiment of the present disclosure. FIG. 2 is a perspective view of the working medium purification device shown in FIG. 1, showing a cold trap body. FIG. 3 is a gas path diagram of the working medium purification device shown in FIG. 1.

[0036] A working medium purification device configured for purifying a refrigeration device is provided according to the present disclosure, which comprises a cold trap mechanism 1, a pipeline mechanism 5 and a desorption mechanism. The cold trap mechanism 1 comprises a cold trap main body 12 and a vacuum cover 11. The cold trap main body 12 is installed on a cold head 3 of a first refrigeration machine and forms heat conduction with the cold head 3 so as to be cooled by the cold head 3 to a first temperature configured for adsorbing impurities. The vacuum cover 11 is arranged outside the cold trap main body 12 and defines a vacuum cavity configured for being extracted to a vacuum state inside the vacuum cover 11 so as to form thermal isolation between the cold trap main body 12 and an external environment. The pipeline mechanism 5 comprises a first branch 51 configured for being arranged in parallel with the cold trap main body 12 on a circulating pipeline 4 of the refrigeration device 9 to be purified and being selectively connected with the circulating pipeline 4. The desorption mechanism is configured to heat the cold trap main body 12 to a second temperature configured for desorbing the impurities in response to a cutoff state of the first branch 51 and extract the impurities in the cold trap main body 12.

[0037] In an illustrative embodiment, as shown in FIGS. 1-3, the working medium purification device further comprises a second vacuum pump 8. In detail, the second vacuum pump 8 is connected to a joint (including but not limited to a standard threaded joint, such as a joint with a model number of KN25) arranged on the vacuum cover 11 through a suction pipeline 7. Further, a sixth valve (i.e., V6 as shown in FIG. 3) is arranged on the suction pipeline 7. In this way, in a state where the cold trap is in a first mode of operation (a working medium flow direction shown by solid arrows in FIG. 3), the vacuum cavity defined in the vacuum cover can be extracted to a vacuum state by the second vacuum pump 8 so as to form thermal isolation between the cold trap main body 12 and an external environment.

[0038] FIG. 4 is a gas circuit diagram of another illustrative embodiment of the working medium purification device shown in FIG. 1.

[0039] Referring to FIG. 4, another illustrative embodiment is shown, in which the working medium purification device is only provided with one vacuum pump (i.e., the first vacuum pump 6). In detail, the suction pipeline 7 is connected to an air inlet end of the first vacuum pump 6.

[0040] In such an embodiment, since the timing of extracting a vacuum in the vacuum cover 11 and the timing of extracting a vacuum in the cold trap main body 12 for desorption are staggered (the timing of extracting a vacuum in the vacuum cover 11 is usually before the working medium purification device is operated, earlier than the desorption cleaning of the cold trap main body 12), therefore, the requirement of extracting a vacuum can be met only by the arrangement of the gas circuit, which not only saves one vacuum pump, but also further reduces the volume of the working medium purification device.

[0041] In an exemplary embodiment, as shown in FIGS. 1 and 2, the cold trap body 12 comprises, but is not limited to, a cylindrical structure configured substantially as a cylinder. In detail, the cold trap body 12 defines an adsorption cavity therein, which is filled with an adsorption material having a porous structure and a high specific surface area. For example, activated carbon, molecular sieve, copper mesh, activated alumina, silica gel, metal adsorbent, and other at least one material configured for adsorbing impurities (such as water vapor, oil vapor, and gas molecules not easily condensed at room temperature) passing through the cold trap body 12 can be used.

[0042] In an exemplary embodiment, as shown in FIGS. 1 and 2, the first refrigerator comprises, but is not limited to, a 70K (Kelvin) low-power pulse tube cryogenic refrigerator. In detail, the cold trap body 12 is directly mounted on the cold head 3 of the first refrigerator, and the cold head 3 as a cold source cools the cold trap body 12 to a first temperature, which comprises, but is not limited to, 77K (Kelvin) or below. It should be understood that embodiments of the present disclosure are not limited thereto.

[0043] For example, the first refrigerator can also use a GM refrigerator (i.e., a Gifford-McMahon refrigerator based on the Joule-Thomson effect) or other refrigerators and / or mechanical cold heads configured for cooling the cold trap body 12 to a first temperature and below.

[0044] In an exemplary embodiment, as shown in FIG. 3, the cold trap body 12 is connected in series to the first branch 51. Further, the first branch 51 also connects the cold trap body 12 in parallel to the circulation pipeline 4 of the refrigeration device to be purified.

[0045] In an exemplary embodiment, as shown in FIG. 3, the circulation pipeline 4 is provided with a first valve (i.e., V1 as shown in FIG. 3). Further, the first branch 51 is provided with a second valve (i.e., V2 as shown in FIG. 3) and a third valve (i.e., V3 as shown in FIG. 3) at the inlet and outlet of the cold trap body 12, respectively.

[0046] The first valve (i.e., V1), the second valve (i.e., V2), and the third valve (i.e., V3) are cooperatively controlled, such that when the first valve (i.e., V1) is in an on state, the second valve (i.e., V2) and the third valve (i.e., V3) are in an off state; correspondingly, when the first valve (i.e., V1) is in an off state, the second valve (i.e., V2) and the third valve (i.e., V3) are in an on state. In this way, the working medium purification device can be switched between a first mode (i.e., the solid arrow direction as shown in FIG. 3) of adsorbing impurities in the working medium (such as helium 3) and a second mode (i.e., the dashed arrow direction as shown in FIG. 3) of not adsorbing the working medium by the cold trap body 12.

[0047] In the state that the working medium purification device is in the second mode (i.e. the direction of the dashed arrow shown in FIG. 3), the desorption mechanism works to clean the impurities in the cold trap main body 12 online (i.e. even if the impurities are desorbed from the adsorption material) during the continuous operation of the refrigeration device, so as to restore the cold trap main body 12 to the second temperature (such as room temperature) and desorption.

[0048] In such an embodiment, the cold trap main body 12 is installed on the cold head 3 of the first refrigerator, and the cold head 3 replaces the liquid nitrogen in the prior art as the cold source, so that the volume of the device can be reduced, and the leakage of the liquid nitrogen can be prevented, thereby improving the safety of the device and avoiding the consumption of the liquid nitrogen. The first branch 51 of the pipeline mechanism 5 connects the cold trap main body 12 in parallel with the circulating pipeline 4 of the refrigeration device, so that the working medium (such as helium 3) can be switched between the circulating pipeline 4 and the cold trap main body 12. The first branch 51 in the cut-off state allows the working medium to pass through the circulating pipeline 4 and isolates the cold trap main body 12 from the working medium, so that the impurities adsorbed by the cold trap main body 12 can be cleaned online by the desorption mechanism.

[0049] Further, the cold trap main body 12 uses the cold head 3 as the cold source, so that the cold trap main body 12 can be adjusted between the first temperature and the second temperature without disassembling the working medium purification device, thereby shortening the time required for cleaning the cold trap main body 12 and improving the convenience of cleaning the cold trap main body 12. In this process, although in the second mode, the working medium (such as helium 3) does not pass through the cold trap main body 12 for impurity removal and directly enters the refrigeration device (such as a dilution refrigerator). However, the time for desorption and cleaning of the cold trap main body 12 (such as about one hour) is negligible compared to the working time of the refrigeration device (such as a dilution refrigerator) (measured in months, such as continuous operation for more than one month), and does not affect the performance and cooling capacity of the refrigeration device (such as a dilution refrigerator). Therefore, online cleaning of the cold trap main body 12 can be achieved. It should be understood that the refrigerators to be purified in the present disclosure include but are not limited to dilution refrigerators.

[0050] For example, the refrigerators to be purified can be any one of a compression-type refrigerator, an absorption-type refrigerator, a Stirling refrigerator, a pulse tube refrigerator, a magnetic refrigerator, and other low-temperature refrigerators. The above and below embodiments are only illustrative examples of the dilution refrigerator, and the working medium purification device can also be applied to any other refrigerators for removing impurities from the working medium by the cold trap mechanism.

[0051] According to an embodiment of the present disclosure, as shown in FIG. 2, the cold trap mechanism 1 further includes an inlet pipe 13 and an outlet pipe 14. The inlet pipe 13 is used as an inlet end of the cold trap main body 12, and the outlet pipe 14 is used as an outlet end of the cold trap main body 12. The inlet pipe 13 and the outlet pipe 14 are arranged side by side and form heat conduction.

[0052] In an exemplary embodiment, as shown in FIG. 2, the gas inlet pipe 13 and the gas outlet pipe 14 of the cold trap mechanism 1 are arranged on the upper portion of the cold trap body 12. In detail, at least a portion of the gas inlet pipe 13 and the gas outlet pipe 14 (e.g., the middle portion shown in FIG. 2, which is substantially parallel to the cold trap body 12) are connected (e.g., welded) side by side, so that the working medium is heat-exchanged with the low-temperature working medium discharged from the gas outlet pipe 14 during the process of entering the gas inlet pipe 13, thereby pre-cooling the working medium before entering the cold trap body 12.

[0053] According to an embodiment of the present disclosure, as shown in FIG. 2, the cold trap body 12 includes a first portion 121 close to the cold head 3 and a second portion 122 away from the cold head 3. The first portion 121 and the second portion 122 are made of different materials, and the thermal conductivity of the first portion 121 is higher than that of the second portion 122.

[0054] According to an embodiment of the present disclosure, as shown in FIG. 2, the cold trap body 12 is provided with an adsorbing material, which is filled in at least the first portion 121.

[0055] In an exemplary embodiment, as shown in FIG. 2, the first portion 121 (e.g., the lower portion shown in FIG. 2) of the cold trap body 12 is made of a different material from the second portion 122 (e.g., the upper portion shown in FIG. 2) of the cold trap body 12. In detail, the first portion 121 and the second portion 122 are integrally made by welding, so as to have good sealing between the first portion 121 and the second portion 122, thereby preventing the working medium from leaking from the cold trap body 12.

[0056] In a preferred embodiment, the first portion 121 is made of copper, and the second portion 122 is made of stainless steel. In such an embodiment, copper has better thermal conductivity than stainless steel, and the copper is installed on the cold head 3 and can be quickly cooled to the first temperature under the action of the cold head 3. The second portion 122 made of stainless steel and the pre-cooled gas inlet pipe 13 can form a relatively uniform temperature gradient for the working medium during the process of entering the cold trap body 12, thereby achieving stepwise cooling and fully utilizing the cold source.

[0057] In an exemplary embodiment, the adsorbing material is filled in the first portion 121. Further, the end portion of the gas inlet pipe 13 located in the cold trap body 12 is inserted into the bottom of the adsorbing material, and the end portion of the gas outlet pipe 14 located in the cold trap body 12 is located in the second portion 122, so that the impurities in the working medium (e.g., helium 3) passing through the adsorbing material are fully adsorbed by the adsorbing material.

[0058] According to an embodiment of the present disclosure, as shown in FIG. 3, the desorption mechanism comprises a heating assembly (not shown in the figure) and a first vacuum pump 6. The heating assembly is configured to heat the cold trap body 12 to a second temperature (e.g. room temperature). The first vacuum pump 6 is in communication with the cold trap body 12 and is configured to extract the impurities desorbed from the cold trap body 12.

[0059] According to an embodiment of the present disclosure, as shown in FIG. 3, the desorption mechanism comprises a heating assembly (not shown in the figure) and a first vacuum pump 6. The heating assembly is configured to heat the cold trap body 12 to a second temperature (e.g. room temperature). The first vacuum pump 6 is in communication with the cold trap body 12 and is configured to extract the impurities desorbed from the cold trap body 12.

[0060] In an exemplary embodiment, the heating assembly and / or the temperature acquisition assembly can be arranged in the cold head 3, wherein the heating assembly comprises but is not limited to an electric resistance heater, a heating belt, a PTC (Positive Temperature Coefficient) heater, a ceramic heater, a heat exchanger and any other heating assembly configured to heat the cold trap body 12 to a second temperature (e.g. room temperature); and the temperature acquisition assembly comprises but is not limited to a platinum resistance (e.g. PT100 or PT1000), a thermocouple, a nickel resistance temperature sensor (i.e. NTC), a diode temperature sensor and any other temperature acquisition assembly configured to acquire the temperature of the cold trap body 12 at a first temperature (e.g. 77K). In detail, since the cold trap body 12 is assembled with the cold head 3, a good thermal conduction is formed, and therefore, the temperature of the cold trap body 12 can be considered to be substantially the same as the temperature of the cold head 3. On this basis, the heating assembly and the temperature acquisition assembly are mounted on the cold head 3, and can be considered to heat and acquire the temperature of the cold trap body 12.

[0061] According to an embodiment of the present disclosure, as shown in FIG. 3, the pipeline mechanism 5 further comprises a second branch 52 arranged between the cold trap body 12 and the circulation pipeline 4. The second branch 52 is in communication with the cold trap body 12 and the circulation pipeline 4 in response to the blocking state of the first branch 51, so as to return the working medium remaining in the cold trap body 12 to the circulation pipeline 4.

[0062] In an exemplary embodiment, as shown in FIG. 3, the second branch 52 is arranged between the gas inlet end (the left end as shown in FIG. 3) of the cold trap main body 12 and the circulation pipeline 4 (the left end of the second branch 52 is not shown). In detail, the fourth valve (i.e., V4 as shown in FIG. 3) is arranged on the second branch 52, and the second branch 52 is maintained in a negative pressure state. The negative pressure state of the second branch 52 is mainly achieved by a pump arranged between the second branch 52 and the circulation pipeline 4. For example, a molecular pump (or other pump, not shown in the figure) can be arranged between the second branch 52 and the circulation pipeline 4. The end of the second branch 52 away from the fourth valve (i.e., V4) is arranged at the front end of the molecular pump (or other pump, not shown in the figure), so that the second branch 52 is in a negative pressure state under the suction of the molecular pump (or other pump, not shown in the figure).

[0063] In an exemplary embodiment, as shown in FIG. 3, the pipeline mechanism 5 further includes a third branch 53. In detail, the first vacuum pump 6 is arranged on the third branch 53. Further, the fifth valve (i.e., V5 as shown in FIG. 3) is arranged between the gas inlet end of the first vacuum pump 6 and the gas inlet end of the cold trap main body 12.

[0064] In a preferred embodiment, in order to facilitate the control of the circulation pipeline 4 and the branches of the pipeline mechanism 5, the above-mentioned valves and pumps can be cooperatively controlled by a corresponding control terminal (such as a PLC, i.e., a programmable logic controller, an upper computer or other equipment). Based on the gas circuit diagram shown in FIG. 3, the first valve (i.e., V1), the second valve (i.e., V2), the fourth valve (i.e., V4), the fifth valve (i.e., V5) and the sixth valve (i.e., V6) can adopt a non-electric closing control mode, and the third valve (i.e., V3) can adopt a non-electric opening control mode.

[0065] In such an embodiment, when the working fluid purification device is in the second mode, the second valve (i.e., V2) and the third valve (i.e., V3) are closed, the first branch 52 is in a cut-off state, and the working fluid is circulated in the refrigeration device through the circulation pipeline 4. At this time, the fourth valve (i.e., V4) is opened, and the residual working fluid (e.g., helium 3) in the cold trap main body is returned to the circulation pipeline 4 (or a working fluid source connected to the circulation pipeline 4) through the negative pressure in the second branch 52 to extract the working fluid, until the gas pressure is lower than a preset value (including but not limited to 10 mbar), and then the fourth valve (i.e., V4) is closed to prevent waste of the working fluid. After the working fluid is extracted, the fifth valve (i.e., V5) is opened, and the cold trap main body 12 is slowly raised to a second temperature (e.g., room temperature) through the heating assembly and stably maintained for a preset time (including but not limited to half an hour), and then the impurities detached from the adsorbent material of the cold trap main body 12 are extracted by the first vacuum pump 6 until the impurities are cleaned. After the impurities are cleaned, the fifth valve (i.e., V5) is closed, and the cold trap main body 12 is cooled by the cold head 3 until the first temperature (e.g., 77 K) is restored and stably maintained for a preset time (including but not limited to half an hour), and then the second valve (i.e., V2) and the third valve (i.e., V3) are opened, and the first valve (i.e., V1) is closed to restore the working fluid purification device to the first mode of adsorbing impurities in the working fluid.

[0066] FIG. 5 is a partial enlarged view of the working fluid purification device shown in FIG. 1, showing an adapter ring.

[0067] In an illustrative embodiment, as shown in FIGS. 1 and 5, the working fluid purification device further includes a connecting mechanism 2 disposed between the cold trap main body 12 and the cold head 3. In detail, the connecting mechanism 2 includes a first flange 21 mounted on the lower end of the cold trap main body 12, a second flange 23 mounted on the upper end of the cold head 3, and a sleeve located between the first flange 21 and the second flange 23. Further, the first flange 21, the second flange 23, and the sleeve 23 define a chamber in communication with the vacuum cavity, which is extracted to a vacuum state under the action of the second vacuum pump 8, thereby maintaining thermal isolation of the connecting position of the cold trap main body 12 and the cold head 3. Among them, the first flange 21 and / or the second flange 23 includes but is not limited to a vacuum clamp flange.

[0068] In an illustrative embodiment, as shown in FIG. 5, the connecting mechanism 2 further includes an adapter ring 24. In detail, the cold trap main body 12 and the cold head 3 are connected through the adapter ring 24. Among them, the adapter ring 24 includes but is not limited to being made of copper material.

[0069] FIG. 6 is a schematic diagram of a refrigeration system according to an illustrative embodiment of the present disclosure.

[0070] Based on the same concept, the present disclosure also provides a refrigeration system, as shown in FIG. 6, comprising at least one refrigeration device 9 to be purified, at least one working medium purification device, and a second vacuum pump 8. The first branch 51 of the working medium purification device is connected in parallel with the circulation pipeline 4 of each refrigeration device 9 and is configured to be selectively and alternately conducted with the circulation pipeline 4. The second vacuum pump 8 is connected in communication with the vacuum cover 11 of the working medium purification device and is configured to extract the vacuum cavity to a vacuum state. The working medium purification device is configured to adsorb impurities in the working medium in response to the conduction state of the first branch 51, and is configured to desorb the impurities in the cold trap body 12 of the working medium purification device in response to the cutoff state of the first branch 51.

[0071] According to an embodiment of the present disclosure, as shown in FIG. 6, the refrigeration system comprises a plurality of refrigeration devices 9 connected in parallel.

[0072] In an illustrative embodiment, as shown in FIG. 6, the refrigeration system comprises, but is not limited to, four refrigeration devices 9, i.e., the first refrigeration device 91, the second refrigeration device 92, the third refrigeration device 93, and the fourth refrigeration device 94 arranged in sequence from left to right in FIG. 6. In detail, each refrigeration device (i.e., the first refrigeration device 91, the second refrigeration device 92, the third refrigeration device 93, and the fourth refrigeration device 94) is configured with a separate circulation pipeline 4. Further, the working medium inlet and the working medium outlet of each refrigeration device 9 are also connected in communication with a working medium purification device. The refrigeration device 9 comprises, but is not limited to, a refrigeration machine, a pipeline connected in communication with the refrigeration machine, a working medium source, a pump, a valve, a detection assembly (such as a pressure gauge, a flow meter, a thermometer, and other metering devices configured to collect the state of the working medium), and other assemblies configured to circulate the working medium between the refrigeration machine and the environment requiring refrigeration.

[0073] In such an embodiment, the impurities in multiple refrigeration devices 9 that are relatively close in space can be cleaned (i.e., impurities are removed) by one working medium purification device. Further, during the initial operation stage of the refrigeration device 9 (during which the working medium carries more gas impurities), it may be difficult for the cold trap mechanism of one working medium purification device to meet the adsorption requirements of a large amount of impurities. Therefore, multiple refrigeration devices 9 can be configured to have different start-up times to share the cold trap mechanism of the working medium purification device among multiple refrigeration devices 9.

[0074] FIG. 7 is a module schematic diagram of a refrigeration system according to another illustrative embodiment of the present disclosure, showing an embodiment with two working medium purification devices.

[0075] According to an embodiment of the present disclosure, as shown in FIG. 7, the refrigeration system comprises at least two working medium purification devices, which are redundant to each other and are selectively conducted with the refrigeration device 9.

[0076] In an illustrative embodiment, two independent working fluid purification devices can be configured in the refrigeration system. In detail, the two working fluid purification devices can be connected to the plurality of refrigeration devices 9 in the refrigeration system as shown in FIG. 7.

[0077] In such an embodiment, the two working fluid purification devices can be connected to each of the refrigeration devices 9 in the refrigeration system, so as to be redundant to each other, i.e., when one working fluid purification device is in the first mode of adsorbing impurities, the other is in the second mode of standby or desorbing the adsorbed impurities. In this way, the refrigeration system can continuously run without a gap where impurities cannot be adsorbed, and can be adapted to the use scenario where a large amount of impurities exist in the gas source. Taking the use scenario of adsorbing impurities in the working fluid of a dilution refrigerator as an example, it can be applied to the initial running state of the dilution refrigerator and / or the running state where the circulating pipeline has a leak point resulting in a large amount of gas impurities being entrained.

[0078] It should also be noted that the directional terms mentioned in the embodiments, such as "up", "down", "front", "back", "left", "right", etc., are only with reference to the drawings, and are not intended to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. When it may cause confusion to the understanding of the present disclosure, the conventional structures or configurations will be omitted.

[0079] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes, and are not intended to limit the scope of the present disclosure. Although each embodiment is described above separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A working fluid purifying device configured to purify a working fluid of a refrigeration apparatus, wherein, include: Cold trap mechanism, including: The cold trap body is mounted on the cold head of the first refrigerator and forms a heat conduction with the cold head so that it is cooled by the cold head to a first temperature configured for adsorbing impurities; A vacuum enclosure is provided on the outside of the cold trap body, and a vacuum chamber is defined inside the vacuum enclosure for being evacuated to a vacuum state so as to thermally isolate the cold trap body from the external environment; Piping system, including: The first branch is configured to connect the cold trap body in parallel to the circulation pipeline of the refrigeration equipment to be purified, and is configured to selectively communicate with one of the circulation pipelines. The desorption mechanism is configured to, in response to the cut-off state of the first branch, heat the cold trap body to a second temperature configured for desorbing impurities and extract impurities from the cold trap body.

2. The purification device of claim 1, wherein, The desorption mechanism includes: A heating assembly is configured to heat the cold trap body to the second temperature; and A first vacuum pump, connected to the cold trap body, is configured to extract impurities desorbed from the cold trap body.

3. The purification device of claim 2, wherein, The heating component is disposed inside the cold head; The desorption mechanism also includes a temperature acquisition component that is communicatively connected to the heating component and is configured to acquire the temperature of the cold head and / or the cold trap body.

4. The purification device of claim 1, wherein, The piping system further includes a second branch disposed between the cold trap body and the circulation pipeline. In response to the cut-off state of the first branch, the second branch connects the cold trap body and the circulation pipeline to allow the working fluid remaining in the cold trap body to flow back to the circulation pipeline.

5. The purification device according to any one of claims 1 to 4, wherein The cold trap mechanism further includes an air inlet pipe and an air outlet pipe, wherein the air inlet pipe serves as the air inlet end of the cold trap body and the air outlet pipe serves as the air outlet end of the cold trap body. The air inlet pipe and the air outlet pipe are arranged side by side and form a heat conduction system.

6. The purification device according to any one of claims 1 to 4, wherein The cold trap body includes a first part close to the cold head and a second part away from the cold head; The first part and the second part are made of different materials, and the thermal conductivity of the first part is higher than that of the second part.

7. The purification device of claim 6, wherein, The cold trap body is provided with an adsorbent material, which fills at least the first part.

8. A refrigeration system wherein, include: At least one refrigeration device to be purified; At least one working fluid purification device as described in any one of claims 1 to 7, wherein a first branch of the working fluid purification device is connected in parallel with the circulation pipeline of each of the refrigeration devices and is configured to selectively communicate with one of the circulation pipelines; as well as The second vacuum pump is connected to the vacuum hood of the working fluid purification device and is configured to extract the vacuum chamber to a vacuum state. The working fluid purification device is configured to adsorb impurities in the working fluid in response to the conduction state of the first branch, and is configured to desorb impurities in the cold trap body of the working fluid purification device in response to the cut-off state of the first branch.

9. The refrigeration system of claim 8, wherein, It includes multiple refrigeration devices connected in parallel.

10. The refrigeration system of claim 8, wherein, It includes at least two working fluid purification devices, which are redundant to each other, and one of them is connected to the refrigeration equipment.

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