CN105135736A - Integral type pulse tube refrigerator phase modulation structure - Google Patents

Abstract

The invention discloses a phase modulation structure of an integral pulse tube refrigerator. The structure adopts the joint phase modulation of a spiral channel and an inner gas storage, and is composed of spiral channels of different sizes and an inner gas storage, and the spiral channel and the inner gas storage are embedded Inside the phase modulation mechanism as a whole. The spiral channel connects the gas outlet at the hot end of the pulse tube and the inner gas reservoir, and is evenly embedded in the periphery of the whole. The inner gas reservoir is located in the middle of the phase modulation mechanism. The beneficial effects of the present invention are: taking the phase modulation device as a whole to improve the space utilization rate; reducing welding and flange joints to increase the overall air tightness; the spiral channel and the inner gas reservoir are embedded in the phase modulation mechanism as a whole to reduce the inertia The gas turbulence caused by tube vibration increases the reliability of the refrigerator.

Description

Phase Modulation Structure of an Integral Pulse Tube Refrigerator

technical field

The invention relates to the field of pulse tube cryogenic refrigeration, in particular to an integral pulse tube refrigerator phase adjustment device.

Background technique

The rapid development of aerospace, space exploration, infrared, atomic energy, superconductivity and other technologies has promoted the continuous development and progress of cryogenic refrigeration technology. As an important branch of cryogenic technology, the pulse tube refrigerator has obvious advantages in the field of cryogenic refrigeration because of its simple structure, low cold head vibration, and high reliability because of its no moving parts at the cold end. The cold end of the pulse tube refrigerator has no moving parts, and the phase relationship between the mass flow and the pressure wave is obtained through the phase modulation mechanism. The inertial tube uses the inertia of the oscillating fluid in the slender tube to adjust the phase difference. It has the advantages of a wide range of phase adjustment and does not greatly increase the power consumption of the compressor. It will not produce a direct current phenomenon similar to that in the two-way intake. It is a high-frequency pulse tube refrigeration. It is a phase modulation method widely used in machines at present, and its structure can also be replaced by impedance type phase adjustment devices such as slits.

Research shows that passive phasing devices such as inertial tubes usually have problems such as large volume, poor sealing and vibration, which are related to the form and arrangement of the phasing device. For the form of the phase modulation mechanism, there are usually structures such as small hole valve gas storage, inertia tube gas storage, two-way air intake, etc. The inertia tube structure usually arranges the pipeline outside the gas storage or outside the compressor to reduce the overall volume . However, the built-in layout of the inertial tubes causes large oscillations, which in turn causes fluctuations in the airflow inside the gas storage. The selection of the inertial tube is usually determined by the phase angle required at the hot end of the pulse tube and the sound power. The inertia in the tube affects the phase angle, and the frictional resistance affects the sound power dissipation. The analysis method of inertial tube usually has one-dimensional, two-dimensional, three-dimensional CFD simulation and simplified thermoacoustic model calculation. CFD can more intuitively see the phase angle change of each part in the tube and the flow state of each position. The simplified thermoacoustic model is currently more accurate. Analyzing the theory of thermoacoustic refrigerator, its calculation of phase modulation is also more accurate.

At present, in the research of phase modulation mechanisms in various countries, especially in the field of designing passive phase modulation mechanisms such as inertial tubes, more focus is on the size and phase modulation rules of various components such as inertial tubes, through a large number of approximate models and experiments. The phase adjustment ability under different sizes is studied, the overall size is reduced by coiling the inertia tube inside the gas storage, and the overall vibration is reduced and the air tightness is increased by adding bushings and welding processes.

Contents of the invention

The purpose of the present invention is to provide a small-scale pulse tube refrigerator integrated phase adjustment device and its optimization method, especially to design the integrated structure of the phase adjustment components to improve the space utilization rate of the small low-temperature refrigerator, reduce vibration, and increase air tightness . The present invention is an improvement on the basis of the overall structure of the original pulse tube refrigerator, and aims to effectively improve the space utilization rate of the overall phase modulation mechanism, reduce vibration, and reduce connections of different components to increase air tightness. The optimized integral structure can change its cross-sectional shape according to the overall layout, make full use of the space, and facilitate the application of actual engineering layout. The process can be completed by mold making or 3D printing technology.

The present invention is an integral pulse tube refrigerator phase modulation structure, which includes a phase modulation mechanism main body 3 , an external joint 4 , a spiral channel 5 , an inner gas storage 6 , and a through hole 7 .

In the phase modulation structure of the integral pulse tube refrigerator, the main body 3 of the phase modulation mechanism is a cylindrical structure, and a light and high-strength titanium material is selected. The hollow part of the cylinder is the inner gas storage 6, and the inner wall of the cylinder is embedded There is a spiral channel 3, and an external joint 4 is provided on the upper end of the main body of the phase modulation mechanism, and the external joint 4 is connected to the hot end connection pipe of the vessel through a flange or a threaded interface detachable part; A through hole 7 is connected to the spiral channel 3 on the inner bottom surface.

The main body 3 of the phase modulation mechanism is in the shape of a non-cuboid or irregular polyhedron.

The spiral channel 5 is a spiral circular channel, a spiral square channel or a spiral slit channel, or a combination of two of the above structures;

The inner gas reservoir 6 is not limited to a cylinder, and its shape should make the volume of the inner gas reservoir the largest in the inner space of the main body 3 of the phase adjustment mechanism.

The specific working process of the phase modulation structure of the integral pulse tube refrigerator is as follows:

The working gas flowing out of the hot end of the pulse tube enters the integral phase modulation structure through the outer joint. The working gas changes the flow state in the spiral channel and enters the inner gas store through the gas storehouse hole; during the working process, the heat generated by the internal friction of the channel can be transmitted through the outer wall surface. The phase angle of the fluid mass flow and pressure wave in the spiral channel changes, the mass flow gradually lags behind the pressure wave, and the phase of the whole machine is changed to improve the efficiency of the whole machine.

Compared with the existing pulse tube refrigeration system, the present invention has the advantages of:

1. The inertia tube and the gas storage are taken as a whole, the inertia tube is replaced by a circular or other cross-section channel, and the gas storage is replaced by the hollow volume in the middle of the overall structure, which greatly reduces the size of the overall phase modulation structure and makes the structure more compact; applied to In engineering, the overall structure can be adjusted according to the actual situation, so as to meet a wider range of refrigerator applications.

2. The circular channel and the void volume are taken as a whole, which reduces the vibration caused when the inertia tube is arranged separately, thereby reducing the airflow fluctuation inside the gas storage and increasing the operating reliability of the refrigerator.

3. The integral layout reduces the connection between different components, reduces bolts, welding and other processes, reduces the complexity of the process to a certain extent, and increases the airtightness of the structure at the same time.

Description of drawings

Figure 1 is a schematic diagram of the coiled structure of a conventional inertial tube external gas store;

Fig. 2 is a schematic diagram of the appearance of the integral phase modulation structure of the present invention;

Fig. 3 is a sectional view of the internal structure of the integral phase modulation mechanism of the present invention;

Fig. 4 is a schematic diagram of the connection structure between the integrated phase modulation mechanism and the pulse tube refrigerator of the present invention;

Labels in the figure:

1. Gas reservoir; 2. External inertia tube; 3. Main body of phase modulation mechanism; 4. External joint; 5. Spiral channel; 6. Internal gas reservoir; 7. Through hole; 8. Compressor connecting pipe; 10. Regenerator; 11. Cold end heat exchanger; 12. Pulse tube; 13. Pulse tube hot end heat exchanger; 14. Phase adjustment mechanism connection pipe.

Detailed ways

In conjunction with the accompanying drawings, the structural principle of the present invention will be further described in detail below.

The integrated pulse tube refrigerator phasing device of the present invention, with reference to accompanying drawing 1, the present invention is the improvement on the conventional pulse tube refrigeration device and system, the main parts of the present invention that are different from the conventional pulse tube system include:

The overall phase modulation mechanism 1, which mainly includes a hot end joint 1-1, a spiral channel 1-2, an internal gas storage connection port 1-3 and an internal gas storage 2;

The hot end joint, the spiral channel and the inner gas storage of the present invention are designed as a whole, and the spiral channel and the inner gas storage are connected through the connecting port of the inner gas storage, as shown in FIG. 3 . The spiral channel changes the relationship between mass flow and pressure wave due to the internal fluid inertia

In the whole 1 of the phase modulation mechanism of the present invention, its hot end joint 1-1 can be designed into any shape according to the size and position of the connection pipe 9 of the phase modulation mechanism, and its function is to enter the working fluid flowing out of the vessel into the integral phase modulation device; The spiral channel 1-2 mainly changes the phase relationship between its mass flow and pressure wave through the flu in the internal fluid, thereby adjusting the phase relationship of each part of the refrigerator as a whole; The vibration caused by the phase mechanism; the phase modulation components as a whole reduces the overall occupied space, and the designer can design any shape and optimize the layout according to the specific situation; the integral structure reduces the connection between different components and increases the overall atmosphere. tightness; the present invention is convenient to control the overall size and layout in application, improves the space utilization rate; reduces vibration, and increases the operational reliability of the refrigerator.

The spiral channel of the present invention can be designed as a spiral circular channel or a spiral square channel, and its specific structural size is given by the designer according to the requirement according to the phase angle to be adjusted. The structure of the present invention can make good use of the layout space of the integral phase modulation structure, combined with the size of the gas storage to meet the required phase modulation requirements.

The present invention can also be an improvement on the structure of the original inertia tube refrigerator, as shown in FIG. 1 . The inertial tube and gas storage in the original inertial tube type refrigerator are manufactured according to the original size into the integrated phase modulation mechanism involved in the present invention, and the shape of the gas storage can be changed according to the size of the inertial tube to adapt to the integral design. Its integral layout is the creative thinking and optimization method of the present invention. The integral material, shape and size can be selected according to the needs of technicians, and its content and improvement methods should fall into the scope of protection of the present invention.

The hot-end joint of the present invention is connected to the hot-end of the pulse tube, and the connection method can also be flange connection or screw connection, and the phase change caused by the connection pipe should be taken into account in the phase adjustment mechanism.

The implementation effect of the present invention is to change the conventional design method of the impedance type phase modulation device of the pulse tube refrigerator, reduce the equipment volume, improve the space utilization rate; reduce the vibration, reduce the internal air flow disorder; increase the air tightness, improve the service life and Machine long-term safety and reliability.

The basic principles and main features of the invention and advantages of the invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments, and what described in the above-mentioned embodiments and the description only illustrates the principles of the present invention, and the present invention will also have other functions without departing from the spirit and scope of the present invention. Variations and improvements are possible, which fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (4)

1. A phase modulation structure of an integral pulse tube refrigerator, which comprises a phase modulation mechanism main body (3), an external joint (4), a spiral channel (5), an inner gas storehouse (6), and a through hole (7), and its Characterized by: In the phase modulation structure of the integral pulse tube refrigerator, the main body (3) of the phase modulation mechanism is a cylindrical structure, and a lightweight and high-strength titanium material is selected. The hollow part of the cylinder is the inner gas reservoir (6), and the cylinder A spiral channel (3) is embedded in the inner wall of the circumference, and an outer joint (4) is arranged on the upper end surface of the main body of the phase modulation mechanism. The bottom surface, that is, the inner bottom surface of the main cylinder of the phase modulation mechanism has a through hole (7) connected to the spiral channel (3). 2. The phase modulation structure of an integral pulse tube refrigerator according to claim 1, characterized in that the main body (3) of the phase modulation mechanism is in the shape of a non-cuboid or irregular polyhedron. 3. The phase modulation structure of an integral pulse tube refrigerator according to claim 1, wherein the spiral channel (5) is a spiral circular channel, a spiral square channel or a spiral slit channel, or is A combination of two of the above structures; 4. The phase modulation structure of a kind of integral pulse tube refrigerator according to claim 1, characterized in that, the described inner gas storage (6) is not limited to a cylinder, and its shape should make the volume of the inner gas storage in the adjusted The internal space of the main body (3) of the camera mechanism is the largest.