Active control alternating-direct flow hybrid mechanical cryogenic system

Abstract

The disclosed subject matter includes an active control alternating-direct flow hybrid mechanical cryogenic system, and relates to the field of cryogenic refrigeration technologies. The active control alternating-direct flow hybrid mechanical cryogenic system includes a main compressor, a Stirling cold finger, an intermediate heat exchanger, a pulse tube cold finger, a first dividing wall type heat exchanger, a final precooled heat exchanger, a second dividing wall type heat exchanger, and an evaporator that are communicated successively, where the second dividing wall type heat exchanger is connected to the evaporator through a second connecting pipeline, and a throttling element is disposed on the second connecting pipeline; a pulse tube cold head of the pulse tube cold finger is communicated with the final precooled heat exchanger through a cold chain; and a check valve is disposed on the intermediate heat exchanger.

Claims

1. An active control alternating-direct flow hybrid mechanical cryogenic system, comprising a main compressor, a Stirling cold finger, an intermediate heat exchanger, a pulse tube cold finger, a first dividing-wall heat exchanger, a final precooled heat exchanger, a second dividing-wall exchanger, and an evaporator that are communicated successively, wherein the second dividing-wall exchanger is connected to the evaporator through a second connecting pipeline, and a throttling element is disposed on the second connecting pipeline; wherein a pulse tube cold head of the pulse tube cold finger is communicated with the final precooled heat exchanger through a cold chain; and wherein a check valve is disposed on the intermediate heat exchanger.

2. The active control alternating-direct flow hybrid mechanical cryogenic system according to claim 1, wherein the main compressor is connected to the Stirling cold finger through a first connecting pipeline.

3. The active control alternating-direct flow hybrid mechanical cryogenic system according to claim 1, further comprising a pressure regulating unit, wherein one end of the pressure regulating unit is communicated with the first dividing-wall heat exchanger, and the other end of the pressure regulating unit is communicated with the main compressor to form a closed direct-flow loop.

4. The active control alternating-direct flow hybrid mechanical cryogenic system according to claim 3, wherein the second dividing-wall heat exchanger is connected to the pressure regulating unit through a JT return pipeline.

5. The active control alternating-direct flow hybrid mechanical cryogenic system according to claim 3, wherein the pressure regulating unit is connected to the main compressor through a JT return connecting pipeline.

6. The active control alternating-direct flow hybrid mechanical cryogenic system according to claim 3, wherein the pressure regulating unit is a conventional oil-free pump, a linear compressor, or a gas reservoir.

7. The active control alternating-direct flow hybrid mechanical cryogenic system according to claim 1, further comprising an oil-free pump, a linear compressor, or a gas reservoir.

8. The active control alternating-direct flow hybrid mechanical cryogenic system according to claim 1, further comprising an oil-free pump, a linear compressor, or a gas reservoir having one end in communication with the first dividing-wall heat exchanger and another end in communication with the main compressor to form a closed direct-flow loop.

9. The active control alternating-direct flow hybrid mechanical cryogenic system according to claim 1, further comprising a pressure regulator having one end in communication with the first dividing-wall heat exchanger and another end in communication with the main compressor to form a closed direct-flow loop.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) To describe the technical solutions in the embodiments of the disclosed subject matter more clearly, the following briefly introduces the accompanying drawings required for describing the embodiments. The accompanying drawings in the following description show merely some example embodiments of the disclosed subject matter, and a person of ordinary skill in the art having the benefit of the present disclosure may still derive other drawings from these accompanying drawings following the same principles disclosed herein.

(2) FIG. 1 is a schematic structural diagram of an active control alternating-direct flow hybrid mechanical cryogenic system according to the disclosed technology. The displayed reference numbers respectively represent: 1—main compressor; 2—first connecting pipeline; 3—Stirling cold finger; 4—intermediate heat exchanger; 5—pulse tube cold finger; 6—pulse tube cold head; 7—check valve; 8—second dividing wall type heat exchanger; 9—throttling element; 10—evaporator; 11—JT return pipeline; 12—pressure regulating unit; 13—JT return connecting pipeline; 14—first dividing wall type heat exchanger; 15—cold chain; and 16—final precooled heat exchanger.

DETAILED DESCRIPTION

(3) The following describes examples of the disclosed subject matter with reference to the accompanying drawings. The described examples are merely representative rather than all possible embodiments of the disclosed subject matter.

(4) According to one aspect of the disclosed subject matter, methods and apparatus are provided for an active control alternating-direct flow hybrid mechanical cryogenic system, and implement an efficient and reliable refrigeration in a temperature zone of 1-4 K and with a compact structure.

(5) To make the foregoing subject matter clearer and more comprehensible, the disclosed subject matter is further described in detail below with reference to the accompanying drawings and specific embodiments.

(6) As shown in FIG. 1, an embodiment provides an active control alternating-direct flow hybrid mechanical cryogenic system. The system can include a main compressor 1, a Stirling cold finger 3, an intermediate heat exchanger 4, a pulse tube cold finger 5, a first dividing wall type heat exchanger 14, a final precooled heat exchanger 16, a second dividing wall type heat exchanger 8, and an evaporator 10 that are communicated successively, so as to couple regenerative alternating flowing and JT direct flowing, to satisfy a cryogenic refrigeration requirement of 1-4 K. The second dividing wall type heat exchanger 8 can be connected to the evaporator 10 through a second connecting pipeline, and a throttling element 9 can be disposed on the second connecting pipeline; a pulse tube cold head 6 of the pulse tube cold finger 5 can be connected to the final precooled heat exchanger 16 through a cold chain 15; a check valve 7 can be disposed on the intermediate heat exchanger 4; fluid can pass through the check valve 7 and implement direct flowing to serve as high pressure fluid for JT refrigeration; the first dividing wall type heat exchanger 14 can be used to precool the high pressure fluid, the throttling element 9 and the check valve 7 can be used for active control, and a controllable ratio relationship between pressure and a flow rate can be adjusted to implement efficient and reliable refrigeration in the temperature zone of 1-4 K and a compact structure.

(7) The main compressor 1 can be connected to the Stirling cold finger 3 through a first connecting pipeline 2.

(8) The active control alternating-direct flow hybrid mechanical cryogenic system can further include a pressure regulating unit 12, wherein one end of the pressure regulating unit 12 can be communicated with the first dividing wall type heat exchanger 14, and the other end of the pressure regulating unit 12 can be communicated with the main compressor 1 to form a closed loop. The pressure regulating unit 12 can be used to increase pressure of return fluid to make it equal to pressure of fluid inside the main compressor 1.

(9) The second dividing wall type heat exchanger 8 can be connected to the pressure regulating unit 12 through a JT return pipeline 11.

(10) The pressure regulating unit 12 can be connected to the main compressor 1 through a JT return connecting pipeline 13.

(11) The pressure regulating unit 12 can be a conventional oil-free pump, a linear compressor, or a gas reservoir.

(12) An example implementation method is as follows:

(13) Helium gas can be compressed in the main compressor 1 to generate alternating flow pressure fluctuation, and enter the Stirling cold finger 3 through the first connecting pipeline 2; a part of gas flowing from the Stirling cold finger 3 can be split and enter the pulse tube cold finger 5 through the intermediate heat exchanger 4; flow-rate-controllable low-temperature helium gas flowing in one way can be exported at the intermediate heat exchanger through the check valve 7, and enter into the throttling element 9 through the second dividing wall type heat exchanger 8; after the low-temperature helium gas passes through the throttling element 9 and is expanded, two-phase low-temperature fluid can be generated in the evaporator 10 to provide cold; the fluid can enter the pressure regulating unit 12 in a normal temperature zone after passing through the second dividing wall type heat exchanger 8 and the JT return pipeline 11, to increase fluid pressure to close to pressure of a back pressure chamber of the main compressor 1; and finally the fluid can enter the main compressor 1 though the JT return connecting pipeline 13 to form a whole closed loop, so as to implement an efficient and reliable refrigeration with a compact structure.

(14) The refrigeration system may simultaneously obtain coldness at a Stirling location (40-80 K), a pulse tube location (10-30 K), and an evaporator (1-4 K).

(15) Conversion between an alternating flow and a direct flow can be implemented at the intermediate heat exchanger component, so as to improve the efficiency of cryogenic pulse tube refrigeration, and obtain a cryogenic compact structure.

(16) The Stirling cold finger 3 can be connected to the pulse tube cold finger 5 through the intermediate heat exchanger 4.

(17) The intermediate heat exchanger 4 can be a structure capable of implementing pulse tube precooling and air flow distribution, and can also be used to precool an air reservoir phase modulation component of an inertia tube of the pulse tube cold finger 5.

(18) The intermediate heat exchanger 4 may be used as a Stirling cold head to obtain cold.

(19) The intermediate heat exchanger 4 may be provided with the check valve 7 for implementing air direct-flow flow in a pulse tube.

(20) A direct flow closed-loop can be implemented through the pressure regulating unit 12 alone, or can be implemented in a manner of combined regulation of the pressure regulating unit 12 and the check valve 7.

(21) The check valve 7 on the intermediate heat exchanger 4 can be a structure that can be opened or closed at a high frequency at low temperature.

(22) The final precooled heat exchanger 16 can be arranged on a high-pressure pipeline, and can be in thermal connection with the pulse tube cold head through the cold chain 15.

(23) A heat exchange flow channel may be machined at the pulse tube cold head, and is used for precooling and heat exchange of direct-flow air flowing out from the intermediate heat exchanger 4 through the second dividing wall type heat exchanger 8.

(24) The second dividing wall type heat exchanger 8 can be added between high pressure air flow flowing out from the intermediate heat exchanger 4 and the final precooled heat exchanger 16, to recover cold.

(25) Several examples are used for illustration of the principles and implementation methods of the disclosed subject matter. The description of the embodiments is used to help illustrate the method and its core principles of the disclosed subject matter. In addition, it will be understood that those of ordinary skill in the art having the benefit of the present disclosure can make various modifications in terms of specific embodiments and scope of application in accordance with the teachings of the disclosed subject matter.

(26) In view of the many possible embodiments to which the principles of the disclosed subject matter may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the claims to those preferred examples. Rather, the scope of the claimed subject matter is defined by the following claims. We therefore claim as our invention all that comes within the scope of these claims.