CN207831999U - A kind of narrow annular channel heat exchanger for acoustic energy refrigeration machine - Google Patents

Abstract

The utility model discloses an annular slit heat exchanger used for a sound energy refrigerator, which belongs to the technical field of heat exchangers. The annular slit heat exchanger for the acoustic energy refrigerator includes an inner rib body and an inner sleeve, the inner rib body is an annular cylinder opened from the inner ring to the outer ring surface, and the inner sleeve is sleeved on the The inner rib body and the interference fit, the inner ring surface of the inner rib body is spaced with a plurality of slits, so that a slit channel for gas flow is formed between the inner rib body and the inner sleeve. The utility model can make the alternating flow of working medium gas and the inner wall of the heat exchanger forced convective heat exchange, and has a relatively large heat transfer coefficient; The interference fit and the welded structure of the inner rib body and the outer fin eliminate the contact thermal resistance; in addition, the inner rib body is made of copper material with a small thermal conduction resistance, so the hot end slit heat exchanger body of the utility model has Better cooling effect.

Description

An annular slit heat exchanger for acoustic energy refrigerator

technical field

The utility model relates to the technical field of heat exchangers, in particular to an annular slit heat exchanger used for a sound energy refrigerator.

Background technique

Acoustic energy refrigerators include Stirling refrigerators, Stirling-type pulse tube refrigerators, etc., using helium or hydrogen to form high-frequency pressure waves in the machine to achieve refrigeration effects, of which Stirling refrigerators use gas expansion refrigeration The closed cycle is formed by the valveless communication between the compression unit and the expansion unit. At present, the Stirling refrigerator is developing towards a large cooling capacity, and the cooling temperature range is also widened, and it is developing towards a medium-high (100K～270K) temperature range. In particular, Stirling refrigerators used in low-temperature refrigerators have a cooling capacity ranging from tens of watts to hundreds of watts.

For a small Stirling refrigerator, the cold accumulator flow path and the compressed cylinder itself used for the compressed helium gas are used as the hot end slit heat exchanger, and there is no need to separately design the hot end slit heat exchanger. But for a Stirling refrigerator with a large cooling capacity, heat dissipation at the hot end is very important, so a hot end heat exchanger needs to be configured. The hot-end slit heat exchanger requires a large heat load, and it is required to minimize the flow resistance of helium in the hot-end slit heat exchanger, and reduce the helium void volume of the hot-end slit heat exchanger. Similarly, the cold end heat exchanger, as an important cooling element of the Stirling refrigerator, is responsible for transferring the cold in the expansion chamber to the outside world, and its heat transfer efficiency is directly related to the refrigeration performance of the refrigerator.

The patent application number is US20040026067, and its name is heat exchanger forstirling refrigerating machine, heat exchanger body, and method of manufacturing heat exchanger body. Its structure (Fig. 1) is to put two different diameter In the concentric ring sleeve, the inner and outer rings of the annular corrugated fins are welded with the inner and outer jackets respectively. This method increases the heat transfer area through the corrugated fins, but it is difficult to manufacture, and it is difficult to keep the flow channel of the corrugated fins uniform, thereby reducing the heat transfer efficiency and increasing the flow resistance; and it is not easy to control the air flow in the annular space. volume.

The Chinese patent publication number CN 1231407A discloses a Stirling refrigeration device using a heat exchanger with a fin structure. It is used in the crank-connecting rod type Stirling refrigerator (Fig. 2), the inner and outer fins are integrally cast, and a water cooling jacket is added on the outer side. In the patent, the inner sleeve and the main body of the heat exchanger are not thermally matched, and the contact thermal resistance will be relatively large, so it is useless to make full use of the heat dissipation area of the inner sleeve.

Utility model content

In view of the above problems, the purpose of this utility model is to provide an annular slit heat exchanger for acoustic energy refrigerators, which can make the alternating flowing working medium gas and the inner wall of the heat exchanger forced convection Heat transfer, and has a large heat transfer coefficient; in the direction of external heat conduction, the interference fit between the inner rib body and the inner sleeve and the welding structure between the inner rib body and the outer fin eliminate the contact thermal resistance; in addition, the inner rib body adopts It is made of copper material with small heat conduction resistance, so the hot end slit heat exchanger body has better heat dissipation effect.

In order to achieve the above object, the technical solution adopted by the utility model is:

An annular slit heat exchanger for an acoustic energy refrigerator, comprising an inner rib body and an inner sleeve, the inner rib body is an annular cylinder opened from the inner ring to the outer ring surface, and the inner sleeve is sleeved on the The inner rib is in an interference fit, and a plurality of slits are spaced apart on the inner ring surface of the inner rib, so that a slit channel for gas flow is formed between the inner rib and the inner sleeve.

Further, the annular slit heat exchanger for an acoustic energy refrigerator further includes a plurality of outer fins, and the plurality of outer fins are evenly fixed on the outer ring surface of the inner rib body.

Further, the slits on the inner ribs are formed by wire cutting.

Further, the inner ribs are made of red copper, the inner sleeve is made of stainless steel, and the outer fins are made of aluminum.

Further, a plurality of the slits are equidistantly opened on the inner ring surface of the inner rib.

Further, the height of the slit channel is 3mm-8mm, the width of the slit channel is 0.2mm-0.5mm, and the width of the inner rib in the inner rib body is 0.6-1.2mm.

Further, the physical thickness from the outer ring surface of the slit channel to the outer ring surface of the inner rib is 0.5-1mm.

Further, the axial length of the slit heat exchanger is 8mm-30mm.

Further, the thickness of the inner sleeve is 0.3-0.5mm.

Further, the fixing method of the outer fin and the outer ring surface of the inner rib body is soldering, and the oxide layer on the surface of the outer fin is removed before welding, and after removing the oxide layer, it is electroplated A layer of nickel.

In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

(1) The utility model can make the alternating flow of working medium gas and the inner wall of the heat exchanger forced convective heat exchange, and has a larger heat transfer coefficient; in the direction of external heat conduction, the inner ribs in the utility model and The interference fit of the inner sleeve and the welding structure of the inner rib body and the outer fin eliminate the contact thermal resistance; in addition, the inner rib body is made of copper material with a small thermal conductivity and thermal resistance, so the hot end slit heat exchanger body has a relatively Good cooling effect. The structure of the utility model also has the characteristics of convenient processing and simple assembly.

(2) The utility model can realize the requirement of heat dissipation at the hot end or cold conduction at the cold end of a Stirling refrigerator with a large cooling capacity, and at the same time meet the helium flow channel arrangement, reduce the empty volume of the heat exchanger and control the flow resistance loss, so as to improve The efficiency of the acoustic energy refrigerator produces a good cooling effect. Moreover, when the utility model is manufactured in large quantities, the wire-cut internal ribs can be cast, which is convenient for processing and manufacturing and low in cost. The utility model has the advantages of compact and efficient structure, high specific surface area, high heat dissipation density and adjustable void ratio.

Description of drawings

Fig. 1 is the schematic structural diagram of the hot end heat exchanger in the U.S. patent application number US20040026067;

Fig. 2 is the structural representation of the hot end heat exchanger in the Chinese patent whose publication number is CN 1231407A;

Fig. 3 is a structural schematic diagram of the hot end slit heat exchanger of the present invention;

Fig. 4 is a partial enlarged view of place A in Fig. 3 and a schematic diagram of internal heat transfer;

Fig. 5 is a schematic diagram of the design parameters of the inner rib body in the utility model;

Fig. 6 is a position diagram of the hot end slit heat exchanger and the cold end slit heat exchanger in the Stirling expander in the embodiment of the utility model;

Fig. 7 is a schematic diagram of the structure of the outer fins in the utility model.

In the figure, 1-inner rib body, 11-inner rib, 2-inner sleeve, 3-outer fin, 4-slit channel, 5-annular cold accumulator.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

It should be noted that when a component is said to be "fixed" to another component, it can be directly on the other component or there can also be an intervening component. When a component is said to be "connected" to another component, it may be directly connected to the other component or there may be intervening components at the same time. When a component is said to be "set on" another component, it may be set directly on the other component or there may be an intervening component at the same time. The terms "vertical," "horizontal," "left," "right," and similar expressions are used herein for purposes of illustration only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of this invention. The terminology used in the description of the utility model herein is only for the purpose of describing specific embodiments, and is not intended to limit the utility model. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in Fig. 3-Fig. 5, an annular slit heat exchanger for an acoustic energy refrigerator includes an inner rib body 1 and an inner sleeve 2, and the inner rib body 1 is a ring opened from the inner ring to the outer ring surface shaped cylinder. The inner sleeve 2 is sheathed in the inner rib body 1 and has an interference fit. The inner ring surface of the inner rib body 1 is provided with a plurality of slits at intervals, and the plurality of slits are arranged in the inner rib body 1. The inner ring surface of the rib body 1 is equidistantly opened, so that a slit channel 4 for gas flow is formed between the inner rib body 1 and the inner casing 2 . The slits on the inner rib body 1 are formed by wire cutting.

When the annular slit heat exchanger used for the acoustic energy refrigerator is used as the hot end slit heat exchanger, it also includes a plurality of outer fins 3, and the plurality of outer fins 3 are uniformly fixed on the inner on the outer ring of the rib 1. In this embodiment, the inner rib body 1 is made of red copper, the inner casing 2 is made of stainless steel, and the outer fins 3 are made of aluminum.

When the slit heat exchanger is used as the hot end heat exchanger, the longitudinal channel of the inner rib body 1 is cut by wire, and it is closely matched with the inner sleeve 2 to form a sealed elongated slit channel 4, and the gas flows through these slits. Flow through the channel 4, using sealed tiny slits to increase the heat exchange area of the gas and reduce the gas volume in the slits, the heat of the gas is directed to the outer fins 3 through the inner ribs 1, and passes through the air on the outside The fan forced convection to dissipate the heat.

When the helium gas discharged from the compression chamber of the acoustic energy refrigerator enters the hot-end slit heat exchanger, the heat exchange between the inner rib body 1 and the inner sleeve 2 in the slit channel 4, as shown in the partially enlarged figure 4, alternates The flowing helium transfers the heat Q1 to the inner rib body 1, transfers the heat Q2 to the inner sleeve 2, and the inner sleeve 2 transfers the heat Q2 to the inner rib body 1, and finally the heat (Q1+Q2) passes through the inner rib body 1 The heat is transferred to the outer fins 3, and the outer fins 3 exchange heat with the outside air through the forced convection of the fan, thereby realizing the heat dissipation process from the helium gas to the environment.

The design parameters of the inner rib body 1 are shown in Figure 5. The width of the slit channel 4 is d1, the height of the slit channel 4 is h1, and the width of the inner rib 11 on the inner rib body 1 is d2. By adjusting d1, h1, d2 can change the void ratio of the slit heat exchanger. In order to ensure that the slit heat exchanger has sufficient heat exchange area to contact and exchange heat with the working fluid gas, the height h1 of the slit channel 4 usually ranges from 3 mm to 8 mm. The slit channel width d1 is usually in the range of 0.2mm-0.5mm. The width d2 of the inner rib 11 in the inner rib body 1 is usually in the range of 0.6-1.2mm. h2 is the physical thickness from the outer ring surface of the slit channel 4 to the outer ring surface of the inner rib body 1, usually in the case that the processing conditions can be achieved and the strength of the slit heat exchanger is satisfied, in order to reduce as much as possible Small h2, thereby increasing the heat transfer area, the range of h2 is usually 0.5-1mm. In this embodiment, the width d1 of the slit channel 4 is preferably 0.3 mm, the height h1 of the slit channel 4 is preferably 5 mm, and the width d2 of the inner rib 11 in the inner rib body 1 is preferably 1 mm.

The axial length of the slit heat exchanger is usually 8mm-30mm. Adjust according to the heat load on the cold or hot end of the chiller. The thickness of the inner sleeve 2 is not easy to be too large, usually about 0.3-0.5mm.

The hot-end slit heat exchanger of the utility model is located between the outlet of the compression chamber of the Stirling refrigerator and the inlet of the regenerator. Body 1 exchanges heat. The advantage of this slit heat exchanger is the forced convection heat exchange between the alternating flowing working medium gas and the inner wall of the heat exchanger, which has a large heat transfer coefficient; The interference fit and the welding structure of the inner rib body 1 and the outer fin 3 eliminate the contact thermal resistance; the inner rib body 1 is made of red copper material, which has a small heat conduction resistance, so the hot end slit heat exchanger body has better heat dissipation Effect. Its structure has the characteristics of convenient processing and simple assembly.

At the same time, the above-mentioned slit heat exchanger can also be used in the cold end heat exchanger. At this time, the outer fin 3 is no longer used on the outside of the cold end heat exchanger to conduct cooling, and the cold head part can be combined with the heat pipe to transfer the cold energy.

An exemplary embodiment of the present invention is explained with reference to FIG. 6 , which is a position diagram of a hot-end slit heat exchanger in a Stirling expander. In an example, a hot end slot heat exchanger is installed between the outlet of the compression chamber and the inlet of the regenerator. Helium releases the heat of compression by alternating flow in the hot-end slot heat exchanger. In the annular regenerator 5, helium releases heat to the regenerator wire mesh before entering the expansion chamber, and absorbs heat from the regenerator wire mesh when returning from the expansion chamber to the regenerator. During this cycle, the hot-end slit heat exchanger also continuously dissipates heat to the environment, while the expansion chamber continuously receives cold energy.

After determining the structure and size required for the design, the manufacturing steps of the hot end slit heat exchanger are as follows:

a. Process inner rib body 1 and inner sleeve 2;

b. Wire cutting the inner rib body 1 made of copper material;

c. Thermally fit the inner rib body 1 with the inner sleeve 2;

d. making outer fins 3;

e. Weld the inner ribs 1 and the outer fins 3 .

In the example, the coaxiality of the inner ring surface of the inner rib 1 should be processed to 0.01mm and the smoothness to 0.8 before wire cutting, and its inner diameter is 40mm as a negative tolerance; the coaxiality of the outer ring surface of the inner sleeve 2 should be 0.01mm and the smoothness to 0.8, the outer diameter of 40mm is a positive tolerance. Its purpose is to ensure the tight fit of the mating surfaces during the interference fit and reduce the contact thermal resistance. The inner rib body 1 is heated to 400° C., it expands under heat, and the diameter of the inner rib 11 expands to more than (40+0.1 mm). Use a special machine to quickly stuff the inner sleeve 2 at room temperature into the hollow part of the inner rib body 1 at high temperature, and after it cools and shrinks, the inner rib body 1 and the inner sleeve 2 can be tightly integrated. Pay attention to the quality control of the diameter size and surface roughness of the inner sleeve 2 and the inner rib body 1, these parameters will have a greater impact on the contact thermal resistance of the tight fit.

The main welding processes of the outer fins 3 include: material pre-treatment, assembly, heating and welding, cooling, post-processing and other processes. The welding method of the outer fin 3 and the outer ring surface of the inner rib body 1 is soldering. Since a very stable oxide layer (AL2O3) will be formed on the aluminum surface in the air, it is difficult to weld copper and aluminum, which is an obstacle The biggest factor of welding, so it must be removed or chemically removed and then electroplated with a layer of nickel, so that copper and aluminum can be welded together smoothly, the welding rate is high, and the heat dissipation performance of the outer fin 3 can be effectively improved . The three-dimensional structure of the outer fins 3 in the utility model is shown in FIG. 7 .

The utility model can realize the requirement of heat dissipation at the hot end or conduction cooling at the cold end of a large-capacity sound energy refrigerator, and at the same time meet the arrangement of helium flow channels, reduce the empty volume of the heat exchanger and control the loss of flow resistance, so as to improve the performance of the sound energy refrigerator. The efficiency to produce a good cooling effect. Moreover, when the utility model is manufactured in large quantities, the wire-cut internal rib body 1 can be cast, which is convenient for manufacturing and low in cost. The utility model has the advantages of compact and efficient structure, high specific surface area, high heat dissipation density and small void ratio.

Claims (10)

1. a kind of narrow annular channel heat exchanger for acoustic energy refrigeration machine, it is characterised in that：Including interior shaft of rib and inner sleeve, the internal-rib Body is the annular barrel that anchor ring opening is faced out by inner ring, and the inner sleeve is sheathed in the internal-rib body and is interference fitted, described It is spaced apart on the inner ring surface of interior shaft of rib and is equipped with multiple slits, it is logical to form the slit that gas flows between the interior shaft of rib and inner sleeve Road.

2. the narrow annular channel heat exchanger according to claim 1 for acoustic energy refrigeration machine, which is characterized in that further include polylith Outer fin, the outer fin of the polylith are uniformly fixedly arranged on the outer ring surface of the interior shaft of rib.

3. the narrow annular channel heat exchanger according to claim 1 for acoustic energy refrigeration machine, it is characterised in that：The interior shaft of rib On slit using wire cutting be molded.

4. the narrow annular channel heat exchanger according to claim 2 for acoustic energy refrigeration machine, it is characterised in that：The interior shaft of rib Using red copper material, the inner sleeve uses stainless steel, the outer fin to use aluminium material.

5. the narrow annular channel heat exchanger according to claim 1 for acoustic energy refrigeration machine, it is characterised in that：It is multiple described narrow Stitch equidistant be opened on the inner ring surface of the interior shaft of rib.

6. the narrow annular channel heat exchanger according to claim 1 for acoustic energy refrigeration machine, it is characterised in that：The slit is logical The height in road is 3mm-8mm, and the width of the narrow-gap channel is 0.2mm-0.5mm, and the width of internal-rib is in the interior shaft of rib 0.6-1.2mm。

7. the narrow annular channel heat exchanger according to claim 1 for acoustic energy refrigeration machine, it is characterised in that：The slit is logical The solid thickness of the outer ring surface in road to the outer ring surface of the interior shaft of rib is 0.5-1mm.

8. the narrow annular channel heat exchanger according to claim 1 for acoustic energy refrigeration machine, it is characterised in that：The slit changes The axial length of hot device is 8mm-30mm.

9. the narrow annular channel heat exchanger according to claim 1 for acoustic energy refrigeration machine, it is characterised in that：The inner sleeve Thickness is 0.3-0.5mm.

10. the narrow annular channel heat exchanger according to claim 4 for acoustic energy refrigeration machine, it is characterised in that：Remove surface After oxide layer and the outer fin of electroless nickel layer and the outer ring surface of the interior shaft of rib use the fixed connection of soldering.