CN219144066U - Quick precooling thermal switch device of dry dilution refrigerator with inserted rod function - Google Patents

Abstract

The utility model discloses a thermal switch device for rapid precooling of a dry dilution refrigerator with the function of an inserting rod, which comprises an inserting rod. The inserting rod includes a first dynamic sealing rod, a second dynamic sealing rod and a The mixing chamber heat transfer element, the still heat transfer element, the secondary heat transfer element, and the primary heat transfer element are stacked in sequence, and the mixing chamber heat transfer element is used to be installed above the sample chamber. The heat transfer element of the mixing chamber is connected with the sample chamber through three supports of springs. The still heat transfer element is connected to the mixing chamber heat transfer element through two spring supports. The secondary heat transfer element is connected to the still heat transfer element through a spring-support. The utility model can realize thermal insulation between the temperature layers of the dilution refrigerator at various stages in the dilution refrigeration stage, and form a heat preservation effect on the dilution unit.

Description

Thermal switch device for rapid precooling of dry dilution refrigerator with plug-in function

technical field

The utility model relates to a thermal switch device for rapid precooling of a dry dilution refrigerator with a rod insertion function, which belongs to the technical field of dry dilution refrigeration.

Background technique

Dry dilution refrigerators usually use mechanical refrigerators (such as G-M refrigerators and pulse-tube refrigerators) to provide cooling capacity down to 3K to pre-cool and insulate the dilution refrigeration unit. In the pre-cooling process, the mechanical refrigerator needs to have sufficient heat exchange with the dilution unit, so as to speed up the cooling speed of the system and ensure the normal operation of the next dilution refrigeration process. During the dilution refrigeration operation, the dilution unit maintains an effective heat insulation state from the surrounding environment, preventing the surrounding environment from transferring heat to the dilution unit at mK temperature. In the existing commercial dry dilution refrigerators, there are two common types: carbon pump heat exchanger and heat exchanger formed by inner vacuum can (IVC). The working principle of the carbon pump heat exchanger is as follows: the 3K plate of the dilution refrigerator (the cold screen thermally connected with the secondary cold head of the mechanical refrigerator) is connected to the cold plates of each level of the dilution unit through a low-temperature heat-insulated sealed stainless steel tube. The stainless steel tube is filled with an appropriate amount of helium, an appropriate amount of activated carbon is placed, and an activated carbon heating device is installed. Activated carbon is heated during pre-cooling to release helium, and the cooling capacity of the secondary cold head of the mechanical refrigerator is transferred to the dilution unit through helium thermal convection. In the dilution refrigeration stage, the heating device is turned off, and the activated carbon adsorbs the helium in the sealed chamber to form an adiabatic state. IVC is to design a vacuum chamber under the 3K disk to contain the entire dilution unit, and the vacuum chamber is thermally connected to the 3K disk. In the pre-cooling stage, helium is filled into the IVC to cool the dilution unit; in the dilution refrigeration stage, the helium is pumped out to keep the dilution unit warm.

The pre-cooling heat exchanger of the existing dry-type dilution refrigerator dilution refrigeration unit has the following two problems: 1. The cooling capacity of the pre-cooling dilution unit comes from the secondary cold head of the mechanical refrigerator, and the cooling capacity is relatively small. As the number of superconducting qubits increases, there are more and more devices in the dilution unit, and the pre-cooling time of the dilution unit will be greatly increased. 2. During the pre-cooling process of the dry dilution refrigerator, the first-stage cold head of the mechanical refrigerator provides a large cooling capacity, and makes the 50K plate of the dilution refrigerator (thermally connected with the first-stage cold head of the mechanical refrigerator) quickly reach At the target temperature, a large part of the cooling capacity of the subsequent primary cold head is wasted.

Utility model content

Purpose of the utility model: In order to overcome the deficiencies in the prior art, the utility model provides a thermal switch device for rapid precooling of a dry dilution refrigerator with a plug-in function, which utilizes the primary cooling capacity of a mechanical refrigerator to realize dilution The rapid precooling of the refrigerator achieves the purpose of reducing the waiting time for precooling and reducing the cost of precooling.

Technical scheme: in order to achieve the above object, the technical scheme adopted by the utility model is:

A thermal switch device for rapid precooling of a dry-type dilution refrigerator with an inserting rod function, comprising an inserting rod, the inserting rod includes a first dynamic sealing rod, a second dynamic sealing rod, and a mixing rod arranged sequentially from bottom to top Chamber heat transfer element, still heat transfer element, secondary heat transfer element, primary heat transfer element, the mixing chamber heat transfer element is used to be installed above the sample chamber. The heat transfer element of the mixing chamber is connected with the sample chamber through three supports of springs. The still heat transfer element is connected to the mixing chamber heat transfer element through two spring supports. The secondary heat transfer element is connected to the still heat transfer element through a spring-support.

The lower end of the first dynamic sealing rod passes through the primary heat transfer element and is fixedly connected with the secondary heat transfer element, and the upper end of the first dynamic sealing rod extends out of the dry dilution refrigerator. The lower end of the second dynamic sealing rod is fixedly connected with the primary heat transfer element, and the upper end of the second dynamic sealing rod extends out of the dry dilution refrigerator.

Preferably: the sample chamber includes a sample cavity and a heat transfer base, and the heat transfer base is fixedly connected with the mixing chamber. The sample cavity is arranged on the heat transfer base, and the position between the sample cavity and the heat transfer base is determined by a positioning rod.

Preferably: the first dynamic sealing rod is provided with a first positioning pin, and the second dynamic sealing rod is provided with a second positioning pin.

Preferably: the positioning rod is a glass fiber epoxy resin rod.

Preferably: the primary heat transfer element, the secondary heat transfer element, the still heat transfer element, and the mixing chamber heat transfer element form sliding thermal contact with the dry dilution refrigerator respectively, and the first dynamic sealing rod, A sliding seal is formed between the second dynamic sealing rod and the dry dilution refrigerator respectively.

Preferably: including a vacuum chamber, a 50k layer, a 4k layer, a still layer, a 100mk layer, and a mixing chamber arranged in sequence from outside to inside, the top of the 50k layer is provided with a first through hole, and the top of the 4k layer is provided with a The second through hole, the top of the still layer is provided with a third through hole, the top of the 100mk layer is provided with a fourth through hole, the top of the mixing chamber is provided with a rod positioning and fixing mechanism, and the first The centers of the first through hole, the second through hole, the third through hole and the fourth through hole are on the same straight line. The positioning and fixing device is provided with a sample chamber for placing samples, the heat transfer part of the mixing chamber is slidably connected to the fourth through hole, the still heat transfer part is slidably connected to the third through hole, the The secondary heat transfer element is slidably connected to the second through hole, and the primary heat transfer element is slidably connected to the first through hole.

Preferably: including a primary cold head and a secondary cold head, the mechanical refrigerator is fixedly installed on the outer surface of the vacuum chamber, the primary cold head is installed on the 50k layer, and the secondary cold head is installed on the 4k layer , and the mechanical refrigerator, the primary cold head, and the secondary cold head are sequentially connected.

Compared with the prior art, the utility model has the following beneficial effects:

1. Use the large cooling capacity of the primary cold head to pre-cool the internal area of the dilution refrigerator from room temperature to 50K. Since the heat capacity of the material from room temperature to 50K is relatively large, the utility model can greatly reduce the pre-cooling of the dry dilution refrigerator. Time, thereby reducing the pre-cooling waiting time and system usage costs.

2. Compared with the traditional thermal switch of dry dilution refrigerator, it has the following advantages: Compared with the carbon pump thermal switch, the method of using solid heat transfer at low temperature is more efficient, and there is no activated carbon failure, helium gas caused by long-term operation. reduction and other issues. The utility model disconnects the contact in the heat insulation stage, and the heat insulation effect is better.

3. The sample to be tested can be directly sent to the lowest temperature of the system without disassembling the system, eliminating the need for system disassembly and assembly environment.

4. Compared with rewarming methods such as feeding gas and heating, this method has high rewarming efficiency, low cost, and no risk of damage to the system.

Description of drawings

Figure 1 is a schematic diagram of the primary pre-cooling state.

Figure 2 is a schematic diagram of the secondary pre-cooling state.

Figure 3 is a schematic diagram of the adiabatic state.

Figure 4 is a schematic diagram of the sample holder.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, further illustrate the utility model, should be understood that these examples are only used for illustrating the utility model and are not intended to limit the scope of the utility model, after having read the utility model, those skilled in the art have a clear understanding of the utility model Modifications of various equivalent forms of the novelty all fall within the scope defined by the appended claims of the present application.

A thermal switch device for rapid precooling of a dry-type dilution refrigerator with a plug-in function, as shown in Figure 1-3, including a plug-in rod, a mechanical refrigerator 8, a primary cold head 9, a secondary cold head 11 and a Vacuum chamber 2, 50k layer 3, 4k layer 4, still layer 5, 100mk layer 6, and mixing chamber 7 are sequentially arranged from outside to inside, the top of the 50k layer 3 is provided with a first through hole, and the 4k layer 4 The top is provided with a second through hole, the top of the still layer 5 is provided with a third through hole, the top of the 100mk layer 6 is provided with a fourth through hole, and the top of the mixing chamber 7 is provided with a rod for positioning and fixing mechanism, and the centers of the first through hole, the second through hole, the third through hole and the fourth through hole are on the same straight line. The positioning and fixing mechanism with plunger is provided with a sample chamber for placing the sample 16 .

The insertion rod includes a first dynamic sealing rod 101, a second dynamic sealing rod 102, and a mixing chamber heat transfer element 14, a still heat transfer element 13, a secondary heat transfer element 12, and a first-stage heat transfer element stacked in sequence from bottom to top. The thermal element 10, the mixing chamber heat transfer element 14 is located above the sample chamber. The heat transfer element 14 of the mixing chamber is slidingly connected to the fourth through hole, and a sliding thermal contact is formed between the heat transfer element 14 of the mixing chamber and the fourth through hole, and the heat transfer element 14 of the mixing chamber is in contact with the sample The chambers are connected by three spring supports. The still heat transfer element 13 is slidingly connected to the third through hole, and a sliding thermal contact is formed between the still heat transfer element 13 and the third through hole, and at the same time, the still heat transfer element 13 is in heat transfer with the mixing chamber Parts 14 are connected by spring two supports. The secondary heat transfer element 12 is slidingly connected to the second through hole, and a sliding thermal contact is formed between the secondary heat transfer element 12 and the second through hole, and at the same time, the secondary heat transfer element 12 is in contact with the still The heat transfer elements 13 are supported and connected by a spring one 15 . The primary heat transfer element 10 is slidingly connected to the first through hole, and a sliding thermal contact is formed between the primary heat transfer element 10 and the first through hole. Spring one 15, spring two, spring three adopt 304 stainless steel springs.

The mechanical refrigerator 8 is fixedly installed on the outer surface of the vacuum chamber 2, the primary cold head 9 is installed on the 50k layer 3, the secondary cold head 11 is installed on the 4k layer 4, and the mechanical refrigerator 8 , the primary cold head 9 and the secondary cold head 11 are connected in sequence.

The lower end of the first dynamic sealing rod 101 passes through the primary heat transfer element 10 and is fixedly connected to the secondary heat transfer element 12, the upper end of the first dynamic sealing rod 101 protrudes from the outer surface of the vacuum chamber 2, and the first The dynamic sealing rod (101) can slide up and down within a certain range without affecting the vacuum degree of the vacuum chamber (2). The lower end of the second dynamic sealing rod 102 is fixedly connected to the primary heat transfer element 10, and the second dynamic sealing rod (101) can achieve a certain range without affecting the vacuum degree of the vacuum chamber (2). Sliding up and down inside, the first dynamic sealing rod 101 and the second dynamic sealing rod 102 can realize the vertical movement from the outside to the inside of the vacuum chamber 2, the first dynamic sealing rod 101 controls the vertical movement of the 4k layer 4, and the second dynamic sealing rod 101 The rod 102 controls the vertical movement of the primary heat transfer element 10 .

As shown in FIG. 4 , the sample chamber includes a sample cavity 171 and a heat transfer base 172 , and the heat transfer base 172 is fixedly connected with the mixing chamber 7 . The sample cavity 171 is disposed on the heat transfer base 172 , and the positioning between the sample cavity 171 and the heat transfer base 172 is performed by a positioning rod 173 . The opening of the heat transfer base 172 is connected with the mixing chamber through screws, and the positioning rod 173 is a glass fiber epoxy resin rod. The effect of glass fiber epoxy resin rod has two: the one, sample cavity 171 is positioned, the hole on the sample cavity 171 and the glass fiber epoxy resin rod (G-10 rod) on the heat transfer base 172 are positioned; Second, the thermal shrinkage rate of glass fiber epoxy resin rod is low at low temperature, and the thermal shrinkage rate of oxygen-free copper is large. Therefore, after inserting the glass fiber epoxy resin rod into the sample holder at room temperature, the hole diameter of oxygen-free copper is reduced at low temperature, and the sample is realized. The cavity 171 and the heat transfer base 172 are in close contact.

The first dynamic sealing rod 101 is provided with a first positioning pin, and the second dynamic sealing rod 102 is provided with a second positioning pin for accurately setting different working modes of the utility model.

The material of the first dynamic sealing rod 101 and the second dynamic sealing rod 102 is 304 stainless steel, and the 304 stainless steel rod with low thermal conductivity can effectively isolate the heat transfer between the 4K and 50K discs and the room temperature end.

The main functions of spring one 15, spring two and spring three are as follows: connecting the heat transfer element 12, the still heat transfer element 13, the mixing chamber heat transfer element 14 and the sample chamber as connectors, so that the utility model forms a plug-in rod in the In the heat insulation stage, the low thermal conductivity of stainless steel and the long distance in the form of springs can effectively isolate the heat transfer between the heat transfer parts; hot.

The primary heat transfer element 10, the secondary heat transfer element 12, the still heat transfer element 13, and the mixing chamber heat transfer element 14 have two functions. In the pre-cooling stage, the heat transfer elements and the cold screens of each level are in contact with each other. , through the form of solid heat conduction, the cold energy generated by the mechanical refrigerator is transferred to the various stages of the dilution refrigerator; in the process of adiabatic, the contact between the heat transfer parts is disconnected, and the heat transfer parts of all levels are in contact with the cold screens of all levels to transfer heat , forming thermal radiation screens at all levels. The primary heat transfer element 10, the secondary heat transfer element 12, the still heat transfer element 13, and the mixing chamber heat transfer element 14 are made of high-purity oxygen-free copper, which can realize rapid heat conduction at low temperature.

A method for using a thermal switch device for rapid precooling of a dry dilution refrigerator with a plug-in function. The utility model can quickly precool the dilution unit of a dry dilution refrigerator. There are three modes of primary precooling, secondary precooling and adiabatic, including the following steps:

Step 1, before use, the heat transfer base 172 is installed on the flange of the mixing chamber in advance, and the insertion rods (the first dynamic sealing rod 101, the second dynamic sealing rod 102, the primary heat transfer element 10, the secondary heat transfer element 12. Still heat transfer element 13, mixing chamber heat transfer element 14, spring 1, 15, spring 2, and spring 3 constitute the overall structure) vertically put into the refrigerator, fix the top flange, then seal the system and evacuate the first Both the dynamic sealing rod 101 and the second dynamic sealing rod 102 are adjusted to the bottom end, so that the sample chamber 171 is in thermal contact with the heat transfer base 172, and at the same time, the primary heat transfer element 10, the secondary heat transfer element 12, and the still heat transfer element 13 , the heat transfer element 14 of the mixing chamber, and the sample chamber 171 are in thermal contact in sequence, and the system is in a first-level pre-cooling state at this time.

Step 2: After vacuuming the system, turn on the mechanical refrigerator for pre-cooling. At this time, due to the large cooling capacity of the first-stage cold head 9 of the refrigerator, the cold screens of each layer inside the dilution refrigerator can be quickly cooled to about 50K.

Step 3, adjust the second dynamic sealing rod 102 upward to set the disconnected state, and the primary heat transfer element 10 rises upward to break contact with the secondary heat transfer element 12, and the system is in the secondary precooling state at this time.

Step 4, the system is further cooled down, and the temperature of the secondary cold head 11 of the mechanical refrigerator is cooled to 3-5K. At this time, heat is conducted through the secondary heat transfer element 12, the still heat transfer element 13, the mixing chamber heat transfer element 14, and the heat transfer base 172 Cool the area inside the 4K screen to around 4K.

Step 5: After the dilution refrigerator is fully pre-cooled, the helium condensation and dilution refrigeration links are performed. At this time, thermal insulation between the stages inside the dilution refrigerator is required, so adjust the first dynamic sealing rod 101 upward to the set off state , at this time, the sample chamber 171 is connected to the heat transfer base 172, and the contact between the primary heat transfer element 10, the secondary heat transfer element 12, the still heat transfer element 13, the mixing chamber heat transfer element 14 and the sample chamber 171 is disconnected, each stage forms thermal insulation. At this time, the heat transfer parts block the openings of all levels to prevent heat radiation from entering, and have the effect of radiation screen. At this point the system is in a state of thermal insulation.

Step 6: When the system returns to temperature, adjust the first dynamic sealing rod 101 and the second dynamic sealing rod 102 to make the system in a first-level pre-cooling state, and quickly return to temperature through the heat transfer of the mechanical refrigerator.

The utility model utilizes the channel of the insert rod of the dry dilution refrigerator to pass through the insert rod (including the first dynamic sealing rod 101, the second dynamic sealing rod 102, the primary heat transfer part 10, the secondary heat transfer part 12, the still heat transfer Part 13, mixing chamber heat transfer part 14, spring one 15, spring two, spring three), through the form of solid heat conduction in the pre-cooling link, the cooling capacity of the first-stage cold head of the mechanical refrigerator is transferred to the dilution unit, accelerating Pre-cooling. During the dilution refrigeration, the device is in the heat insulation stage, and the stages of the device are in thermal contact with the stages of the dilution refrigerator, and are thermally insulated between the stages of the insertion rod, forming a heat preservation effect on the dilution unit.

The above is only a preferred embodiment of the utility model, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements and modifications can also be made. Retouching should also be regarded as the scope of protection of the present utility model.

Claims (7)

1. A thermal switch device for rapid precooling of a dry-type dilution refrigerator with an insert rod function, characterized in that: it includes an insert rod, and the insert rod includes a first dynamic sealing rod (101), a second dynamic sealing rod ( 102) and the mixing chamber heat transfer element (14), still heat transfer element (13), secondary heat transfer element (12), and primary heat transfer element (10) arranged sequentially from bottom to top, the mixing chamber The heat transfer element (14) is used to be installed above the sample chamber; the mixing chamber heat transfer element (14) is connected with the sample chamber by three spring supports; the still heat transfer element (13) is connected to the mixing chamber for heat transfer Parts (14) are connected by spring two supports; The secondary heat transfer element (12) is connected to the still heat transfer element (13) by a spring-support; The lower end of the first dynamic sealing rod (101) passes through the primary heat transfer element (10) and is fixedly connected with the secondary heat transfer element (12), and the upper end of the first dynamic sealing rod (101) extends out of the dry type Outside the dilution refrigerator; the lower end of the second dynamic sealing rod (102) is fixedly connected to the primary heat transfer element (10), and the upper end of the second dynamic sealing rod (102) extends out of the dry dilution refrigerator. 2. The thermal switch device for rapid precooling of the dry dilution refrigerator with the function of inserting rod according to claim 1, characterized in that: the sample chamber includes a sample cavity (171) and a heat transfer base (172), the The heat transfer base (172) is fixedly connected with the mixing chamber (7); the sample cavity (171) is arranged on the heat transfer base (172), and the sample cavity (171) and the heat transfer base (172) pass through Positioning rod (173) is positioned. 3. According to claim 2, the thermal switch device for rapid precooling of the dry-type dilution refrigerator with the function of inserting rods, characterized in that: the first dynamic sealing rod (101) is provided with a first positioning pin, and the A second positioning pin is arranged on the second dynamic sealing rod (102). 4. The thermal switch device for rapid precooling of the dry-type dilution refrigerator with the function of inserting rods according to claim 3, characterized in that: the positioning rod (173) is a glass fiber epoxy resin rod. 5. The thermal switch device for rapid precooling of the dry-type dilution refrigerator with the function of inserting rods according to claim 4, characterized in that: the primary heat transfer element (10), the secondary heat transfer element (12), The still heat transfer element (13), the mixing chamber heat transfer element (14), respectively form sliding thermal contact with the dry dilution refrigerator, and the first dynamic sealing rod (101), the second dynamic sealing rod (102) Form a sliding seal with the dry dilution refrigerator respectively. 6. According to claim 5, the thermal switch device for rapid precooling of the dry-type dilution refrigerator with the function of inserting a rod, is characterized in that: it comprises a vacuum chamber (2), a 50k layer (3), 4k layer (4), still layer (5), 100mk layer (6), mixing chamber (7), the top of the 50k layer (3) is provided with a first through hole, and the top of the 4k layer (4) is provided with There is a second through hole, the top of the still layer (5) is provided with a third through hole, the top of the 100mk layer (6) is provided with a fourth through hole, and the top of the mixing chamber (7) is provided with an insertion hole Rod positioning and fixing mechanism, and the centers of the first through hole, the second through hole, the third through hole, and the fourth through hole are on the same straight line; the positioning and fixing device is provided with a sample (16) The sample chamber of the mixing chamber is slidably connected between the mixing chamber heat transfer element (14) and the fourth through hole, the still heat transfer element (13) is slidably connected with the third through hole, and the secondary heat transfer element (12) is in sliding connection with the second through hole, and the primary heat transfer element (10) is in sliding connection with the first through hole. 7. According to claim 6, the thermal switch device for rapid precooling of the dry-type dilution refrigerator with the function of inserting a rod, is characterized in that: it includes a primary cold head (9), a secondary cold head (11), a mechanical refrigerator (8) fixedly installed on the outer surface of the vacuum chamber (2), the first-level cold head (9) is installed on the 50k layer (3), and the second-level cold head (11) is installed on the 4k layer (4), And the mechanical refrigerator (8), the primary cold head (9), and the secondary cold head (11) are sequentially connected.

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