JP3258854B2 - Stirling refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Stirling refrigerating apparatus for realizing an ultra-low temperature state in a freezing box using a Stirling engine.

[0002]

2. Description of the Related Art A refrigeration system using a Stirling engine is relatively easy to maintain, absorbs heat when the working gas expands, cools the inside of the refrigeration box from -60.degree. C. to a very low temperature of about -200.degree. It is suitable for cooling products to ultra-low temperatures and is about to be widely used in various fields.

FIG. 7 is a partial cross-sectional view showing the inside of this type of Stirling refrigerating apparatus.
Has a compression chamber 3 for compressing the working gas in front of the first piston 2 fitted in the compression cylinder portion 2a, while expanding the working gas in front of the second piston 4 fitted in the expansion cylinder portion 4a. The compression chamber 3 and the expansion chamber 5 communicate with each other through a gas flow path through a heat regenerator and a radiator (not shown), and the first piston 2 and the second piston 4 is configured to reciprocate by a crank mechanism 7 driven by a motor with a certain phase difference.

On the other hand, a freezing box 10 is disposed above the Stirling engine 1, and is filled with a heat insulating material 13 such as urethane between a box-shaped outer box 11 and an inner box 12. Has a heat conductive plate 14a attached to a side wall while a heat conductive plate 14b is attached to a bottom wall, and a plate as a refrigeration load is surrounded by the heat conductive plates 14a and 14b. A freezer compartment 15 for storing the frozen product is formed, and a lid 16 for taking in and out the frozen product is provided at a frontage portion of the upper portion of the freezer compartment 15.

Further, the freezing box 10 has a heat conducting portion 18 as a cold head for conducting cold heat from the Stirling engine 1 at a lower portion. One end of the heat conducting portion 18 is connected to the tip of the expansion cylinder portion 4a. , The other end is joined to the bottom surface of the heat conductive plate 14b.

With the above configuration, when the prime mover is driven, the crank mechanism 7 causes the first piston 2 and the second piston 4 to reciprocate with a certain phase difference. First, the first piston 2 moves to compress the working gas such as helium filling the compression chamber 3, and the compressed and heated working gas is radiated by a radiator (not shown) and further cooled by a heat regenerator (not shown). After that, it is led to the expansion chamber 5. After that, the lowering of the second piston 4 causes an expansion stroke in which the working gas in the expansion chamber 5 expands, and the expansion of the working gas lowers the working gas to cool the heat conducting portion 18. Due to the rise of 4, the low-temperature working gas in the expansion chamber 5 is pushed out and guided to the compression chamber 3 while cooling the heat regenerator.

The above steps are sequentially repeated, and when the working gas in the expansion chamber 5 is expanded, the heat conducting portion 18 of the expansion cylinder portion 4a is expanded.
Is cooled, so that the heat conducting portion 18 is connected to the heat conducting plate 14.
The temperature of the freezing compartment 15 of the freezing box 10 is gradually lowered through the a and 14b, and the temperature of the upper portion of the heat conducting portion 18 of the expansion cylinder portion 4a is set to about -200 ° C. by repeating this process. The freezing compartment 15 receives the freezing heat from the heat conducting part 18 via the heat conducting plate 14a, so that the center part is approximately -180 ° C.
And The freezing heat is transmitted to the periphery of the freezer compartment 15 from the heat conducting portion 18 via the heat conducting plate 14a by the heat conducting plate 14b, and the temperature is set to about -170 ° C., which is lower than the central portion.
Thereby, frozen products such as blood, medicines and various bacteria can be stored in the freezer compartment 15 at an extremely low temperature.

[0008]

By the way, in the Stirling refrigerating apparatus shown in FIG. 7, it was difficult to quickly set the freezing chamber 15 to the freezing temperature. That is, first, the Stirling engine 1 uses the heat conducting portion 1 as a cold head.
Even if 8 is near the freezing temperature, it takes a considerable time for cold heat to be transmitted from the heat conducting portion 18 to the freezing compartment 15 via the heat conducting plate 14b and the heat conducting plate 14a, and the freezing compartment 15 is rapidly frozen. There was a problem in using it for business.

Accordingly, an object of the present invention is to provide a Stirling refrigerating apparatus capable of rapidly setting a load to be frozen to a refrigerating temperature.

[0010]

According to a first aspect of the present invention, an expansion stroke of a working gas guided from a compression chamber formed at a front portion of a compression cylinder portion to an expansion chamber formed at a front portion of an expansion cylinder portion is provided. A Stirling engine that generates cold heat by a heat cycle process including at least a heat conduction portion that is formed at the tip of the expansion cylinder portion and that conducts the cold heat generated in the expansion chamber; In a Stirling refrigerating apparatus provided with a freezing box forming a freezing room for accommodating a load, a heat conducting portion is protruded into the freezing room, and is separated from an inner wall formed by a heat conducting plate and fitted to the heat conducting portion. A heat conduction block for transmitting refrigeration heat to a refrigeration load is provided.

According to a second aspect of the present invention, a recess is formed in the heat conduction block so as to be fitted to the projecting portion of the heat conduction portion so as to be separated from the inner wall formed by the heat conduction plate, while being formed by the heat conduction plate. The heat conduction block is provided with a concave portion which is fitted to the projecting portion of the heat conduction portion so as to be in contact with the inner wall.

[0012]

According to the first aspect of the present invention, the refrigeration heat is thermally conducted directly and intensively from the heat conducting portion protruding into the freezing chamber to the heat conducting block. Along with this, the refrigeration load can be rapidly brought to the refrigeration temperature.

According to the second aspect of the present invention, the heat conduction block can be separated from the bottom surface of the freezer compartment and the heat conduction block can be in contact with the bottom surface of the freezer compartment according to the purpose. Therefore,
Quick freezing and normal freezing can be used properly.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 are schematic sectional views of a Stirling refrigerating apparatus showing an embodiment of the present invention. In FIG. 1, the same reference numerals as those shown in FIG. 2 and FIG. 2 are provided with a freezing box 10A having a different configuration from the freezing box 10 shown in the conventional example.

That is, the freezing box 10A is disposed above the Stirling engine 1 similar to that described with reference to FIG. 7, and is filled with a heat insulating material 13 such as urethane between a box-shaped outer box 11 and an inner box 12. On the inner peripheral wall of the inner box 12, a plate having good heat conduction is adhered to the side wall as the heat conduction plate 14a, while the heat conduction plate 14a is adhered to the bottom wall.
A freezer compartment 15 for storing a frozen product as a refrigeration load is formed on the inner side surrounded by a and 14b.
A lid 16 for taking in and out the articles to be frozen is provided at the frontage of the upper part of the apparatus 5. Incidentally, reference numeral 6 in FIG. 2 indicates a prime mover of the crank mechanism 7.

Further, the freezing box 10A has a lower portion, in which a tip of a heat conducting portion 18 which is a cold head for conducting heat from the Stirling engine 1 is protruded into the freezing compartment 15, and a heat conducting portion is connected to the tip of the heat conducting portion 18. The block 19 is attached as described later, and the sample shelf 20 is placed on the heat conduction block 19, and the rear end of the heat conduction section 18 is connected to the front end of the expansion cylinder section 4a.

Next, as shown in FIG. 5, the tip of the heat conducting portion 18 has a semi-cylinder 18a having a dimension L which is smaller than that of the semi-circular portion 18b.
And the corresponding heat conducting block 19 is also formed with a semicircular recess so as to fit into the half cylinder 18a. Then, for example, the heat conduction block 14 in which the heat conduction block 19 is fitted to the half cylinder 18a of the heat conduction portion 18 shown in FIG.
b. Further, the half cylinder 18a shown in FIG.
The half cylinder 1 as a spacer shown in FIG.
8c are placed in contact with each other, and the heat conduction block 19 is changed by 180 degrees to be fitted so that the heat conduction block 19 is separated from the heat conduction plate 14b by a dimension L. FIG.
The semi-cylinder 18c shown in FIG. 4 is made of the same material as the heat conducting portion 18 and has the same radius as the heat conducting portion 18 and a dimension of 2L.

According to this configuration, the heat conduction portion 18 and the heat conduction block 19 can be always in close contact with each other when the heat conduction block 19 is in contact with the heat conduction plate 14b and when the heat conduction block 19 is separated therefrom.

With the above configuration, when the inside of the freezer compartment 15 is rapidly frozen, the heat conduction block 19 is heat-conductive as shown in FIGS. 1 and 2 from the positional relationship between the tip of the heat conduction section 18 and the heat conduction block 19. Move away from the plate 14b.

For example, a heat conducting block 18 shown in FIG. 5 is placed in contact with a heat conducting portion 18 having a projecting semi-cylinder 18a as shown in FIG. 19 is fitted.

As a result, the heat conducting block 19 floats from the heat conducting plate 14b by the dimension L, and the refrigeration heat of the heat conducting portion 18 is directly and intensively conducted to the heat conducting block 19, and the heat conducting block 19 is rapidly frozen. And the sample 20a on the sample shelf 20 is frozen. Therefore, the sample 20a can be quickly frozen as compared with the conventional case where the inside of the freezer compartment 15 is frozen via the heat conduction plate 14b.

When rapid freezing is not required, if the positional relationship between the tip of the heat conducting portion 18 and the heat conducting block 19 is changed, the heat conducting block 19 comes into contact with the heat conducting plate 14b as shown in FIGS. Can be frozen. For example, the semi-circular concave portion of the heat conduction block 19 is fitted to the heat conduction portion 18 projecting the semi-cylinder 18a shown in FIG. Although the spacers are used in the description shown in FIGS. 5 and 6, the recesses formed in the heat conduction block 19 may be provided separately for quick freezing and normal use. In this case, the position of the concave portion of the heat conduction block 19 is shifted according to the purpose and fitted, or the concave portion is provided on the front and back of the heat conduction block 19 and inverted. Thus, the Stirling refrigerating apparatus can be applied to quick freezing and normal freezing as required. The heat conduction block 1 is used exclusively for quick freezing.
9 and the heat conducting part 18 may be fixed.

[0024]

As described above, according to the first aspect of the present invention, since the refrigeration heat is directly and intensively conducted to the heat conduction block from the heat conduction portion protruding into the freezer compartment, the refrigeration load is reduced. Can be quickly brought to the freezing temperature.

According to the second aspect of the present invention, the heat conduction block can be separated from the bottom surface of the freezing compartment, and the heat conduction block can be in contact with the bottom surface of the freezing compartment. it can.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a Stirling refrigerating apparatus showing one embodiment of the present invention.

FIG. 2 is a side sectional view of a Stirling refrigerating apparatus showing one embodiment of the present invention.

FIG. 3 is a front sectional view of the Stirling refrigerating apparatus showing a state in which the heat conduction block corresponding to FIG. 1 is in contact with the heat conduction plate.

FIG. 4 is a side sectional view of the Stirling refrigerating apparatus showing a state in which the heat conduction block corresponding to FIG. 2 is in contact with the heat conduction plate.

FIG. 5 is an explanatory view showing a tip of a heat conducting unit provided in FIGS. 1 to 4;

FIG. 6 is an explanatory view showing a spacer of a heat conducting part in FIG. 5;

FIG. 7 is a front sectional view showing a conventional Stirling refrigerating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stirling engine 2 1st piston 2a Compression cylinder part 3 Compression chamber 4 2nd piston 4a Expansion cylinder part 5 Expansion chamber 6 Prime mover 7 Crank mechanism 10A Freezing box 11 Outer box 12 Inner box 13 Heat insulating material 14a, 14b Heat conduction plate 15 Freezing Chamber 16 Lid 18 Heat conduction part 18a, 18c Half cylinder 18b Semicircle part 19 Heat conduction block 20 Sample shelf

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F25B 9/14 520 F25B 9/00 F25D 11/00 101

Claims (2)

(57) [Claims] 1. Stirling that generates cold heat by a heat cycle process including at least a process of expanding a working gas guided from a compression chamber formed at a front portion of a compression cylinder portion to an expansion chamber formed at a front portion of an expansion cylinder portion. An engine, a heat conducting part formed at the tip of the expansion cylinder part to conduct heat of the cold generated in the expansion chamber, and a freezer box having an inner wall formed of a heat conducting plate to form a freezing chamber for storing a freezing load. In the Stirling refrigerating apparatus, the heat conduction portion is protruded into the freezing chamber, and the refrigeration heat is applied to the refrigeration load which is separated from an inner wall formed by the heat conduction plate and fitted to the heat conduction portion. A Stirling refrigerating apparatus comprising a heat conduction block for conducting heat. 2. A heat-conducting block, wherein a recess is formed in the heat-conducting block so as to be spaced from an inner wall formed by the heat-conducting plate, the concave portion being fitted to a protruding portion of the heat-conducting portion. The Stirling refrigerating apparatus according to claim 1, wherein a concave portion is formed in the heat conductive block so as to be fitted to the projecting portion of the heat conductive portion so as to be in contact with an inner wall.