JP2000274855A - Stirling cooler and method for sealing its cooling water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress mixture of air within cooling water piping in the step of sealing cooling water in the piping by interposing an annular packing made of a member having a low thermal conductivity between a compressing cylinder block and an expansion cylinder block. SOLUTION: An expansion piston 42 for expanding operating gas of an expansion chamber 41 by reciprocating out of phase deviated at substantially 90 from that of a compression piston 36 is engaged within an expansion cylinder block 40 coupled to a compression cylinder block 34, and the chamber 41 is coupled to a compression chamber 3'7 through a gas channel so that the gas moves back and forth therebetween. A radiating heat exchanger is arranged at the channel, and a cooling head connected with a cold heat utilizing equipment is arranged on a periphery of the expansion chamber. In such a Stirling cooler, a packing 101 having an extremely low thermal conductivity such as ceramics or the like is interposed between both the blocks 40 and 34 to reduce a heat transfer from the block 34 to the block 40, thereby improving its refrigerating capability.

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 having improved thermal conductivity between a compression cylinder block and an expansion cylinder block, and a Stirling refrigerating apparatus in which air is not mixed into a circulation system of cooling water when charging cooling water. The present invention relates to a method of filling cooling water in a device.

[0002]

2. Description of the Related Art Generally, a compression cylinder block, a compression piston that slides in the compression cylinder block and compresses a working gas in a compression chamber, an expansion cylinder block connected to the compression cylinder block, and an expansion cylinder 2. Description of the Related Art There is known a Stirling cooling apparatus including an expansion piston that reciprocates in a block with a phase difference of about 90 from the compression piston to expand a working gas in an expansion chamber.

A Stirling refrigerator used in this type of Stirling cooling apparatus generates cold by compressing and expanding a working gas.

As described above, this Stirling refrigerator has a compression section provided with a compression piston for compressing the working gas in the compression chamber, an expansion section provided with an expansion piston for expanding the working gas in the expansion chamber, and the like. The compression chamber and the expansion chamber are communicated by a gas flow path. The gas flow path is provided with a heat-radiating heat exchanger that cools the working gas that has been compressed to a high temperature,
The refrigeration efficiency of the Stirling refrigerator is increased by lowering the temperature of the working gas flowing from the compression chamber to the expansion chamber.

At this time, a radiator for exchanging heat of the cooling water with the outside air or the like is provided in order to enhance the heat radiation efficiency of the heat radiation heat exchanger. The heat radiator and the radiator are connected by a cooling water pipe, and the cooling water is circulated by being pumped by a cooling water pump.

[0006]

However, in the conventional structure, first, the compression cylinder block which is about -80 ° C is made of iron (FC250), and the expansion cylinder block which is about 90-100 ° C is made of stainless steel. So that
There is a problem that heat transfer from the compression chamber side to the expansion chamber side is large and the refrigeration efficiency is reduced.

Second, air may be mixed into the cooling water pipe in the process of filling the cooling water into the cooling water pipe. If air is mixed in, the cooling water pump will not be able to circulate the cooling water properly due to the air biting. In such a case, the heat of the working gas sent from the compression chamber to the expansion chamber is not sufficiently radiated, so that the refrigeration efficiency of the Stirling refrigerator is reduced.

Therefore, an object of the present invention is to solve the problems of the prior art, improve the thermal conductivity between the compression cylinder block and the expansion cylinder block, and perform cooling in the process of filling cooling water into cooling water piping. It is an object of the present invention to provide a Stirling cooling device that suppresses air from being mixed into a water pipe, and a method of filling cooling water therewith.

[0009]

According to the first aspect of the present invention,
A compression cylinder block, a compression piston that slides in the compression cylinder block and compresses the working gas in the compression chamber, an expansion cylinder block connected to the compression cylinder block, and the compression piston in the expansion cylinder block. The expansion piston reciprocates with a phase shift of about 90 to expand the working gas in the expansion chamber, and the compression chamber and the expansion chamber are connected to each other so that the working gas moves back and forth between them. In a Stirling cooling device having a gas flow path, a heat radiation heat exchanger connected to the gas flow path, and a cooling head provided around the expansion chamber and capable of connecting a cold heat utilization device, An annular packing formed of a member having low thermal conductivity is interposed between the compression cylinder block and the expansion cylinder block. .

According to a second aspect of the present invention, in the first aspect, an annular concave portion is formed on a joint surface of the compression cylinder block and / or the expansion cylinder block.
The annular packing is attached to the concave portion, and the compression cylinder block and the expansion cylinder block are connected to each other.

According to a third aspect of the present invention, there is provided a compression piston for compressing a working gas in a compression chamber, an expansion piston reciprocating out of phase with the compression piston by approximately 90 to expand the working gas in the expansion chamber. A gas flow path that connects the compression chamber and the expansion chamber and connects the working gas to and fro between them; and a gas flow path provided in the gas flow path and compressed by the compression chamber to increase the temperature. A heat-radiating heat exchanger for exchanging heat between the working gas and the cooling water, a circulation path including a cooling-water pipe for circulating the cooling water through the heat-radiating heat exchanger, and a cooling water connected to the cooling-water pipe In the method of filling a cooling water of a Stirling cooling device having a pump for cooling, a cooling water pipe on a suction side of the cooling water pump is separated, and each end of the separated cooling water pipe is submerged in water of the same tank. Air comes out into the water Water was sealed in the circulation path wherein is operated cooling water pump to Kunar, it is characterized in that for connecting the ends of the cooling water pipes disconnected in water of the same tank.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a Stirling cooling device according to the present invention.
In the figure, a Stirling refrigerator 3 is provided in a box-shaped case 2. The Stirling refrigerator 3 is provided with a cooling head 4, and a cooling / cooling refrigerant pipe 5 is connected to the cooling head 4 so that the cooling / cooling refrigerant circulates. Note that the cold refrigerant refers to a refrigerant for transporting the cold generated by the Stirling refrigerator 3 to a cold utilization device 8 such as a freezer. Both ends of the cold refrigerant pipe 5 are connected to an inlet plug 6 and an outlet plug 7 fixed to the case 2, and the inlet plug 6 and the outlet plug 7 are connected to an outlet end 9 of a cold refrigerant pipe of a cold heat utilization device 8. The inlet ends 10 are each detachably connected.

A cryogen pump P2 is provided in the cryogen pipe 5 so that the cryogen circulates between the cooling head 4 and the cryogenic equipment 8. In addition, as the cold energy utilization device 8, in addition to the freezer, a refrigerator, a throw-in type cooler, a low-temperature liquid circulator, a low-temperature constant temperature device for various temperature characteristic tests, a constant-temperature bath, a heat shock test device, a freeze dryer, a cold cooler, and the like are included. Applicable.

A cylinder 12 is formed at the top of the housing of the Stirling refrigerator 3, and a motor chamber 14 and a crank chamber 1 are formed inside the housing by a partition wall 13.
5 is divided. The motor chamber 14 is provided with a motor 16 capable of normal and reverse rotation, and the crank chamber 15 is provided with a rotary reciprocating conversion mechanism 17 for converting the rotational operation of the motor 16 into reciprocating motion. The opening 18 of the motor chamber 14 and the opening 19 of the crank chamber 15 are closed by lids 20 and 21, respectively, and the inside of the housing is held in a semi-sealed state. In the housing, a crankshaft 23 penetrating the partition wall 13 and rotatably supported by the housing wall, the partition wall 13 and the bearings 22 of the lids 20 and 21 is rotatably arranged. The motor 16 includes a stator 24a and a rotatable rotor 24b on the inner peripheral side of the stator 24a.
The crankshaft 23 is fixed to the center of the rotor 24b.

The rotary reciprocating conversion mechanism 17 includes the crank chamber 1
5, a crank portion 25 of the crankshaft 23 extending into
Connecting rods 26, 2 connected to the crank 25
7. It is composed of cross guide heads 28 and 29 attached to the tips of the connecting rods 26 and 27, and functions as a driving means of the Stirling refrigerator 3. The cross guide heads 28 and 29 are arranged to be able to reciprocate in cross guide liners 30 and 31 provided on the inner wall of the cylinder 12.

The crank portion 25 is formed with a phase difference so that the crank 25b moves ahead of the crank 25a when the motor 16 rotates forward. As this phase difference, a phase difference of 90 degrees is generally adopted. A compression cylinder 32 and an expansion cylinder 33 located slightly above the compression cylinder 32 are disposed above the crank chamber 15. A working gas such as helium, hydrogen, or nitrogen is sealed in the housing including the compression cylinder 32 and the expansion cylinder 33.

The compression cylinder 32 has a compression cylinder block 34 fixed to the housing with bolts or the like. A compression piston 36 provided with a piston ring 35 reciprocates in the space of the compression cylinder block 34,
The upper part (compression chamber) of this space is a high-temperature chamber 37, in which the working gas is compressed to a high temperature.

The compression piston rod 38 has one end fixed to the compression piston 36 and the other end extended through an oil seal 39, and is rotatably connected to the cross guide head 28 by a pin. The speed of the reciprocating compression piston 36 becomes zero because the sliding direction is reversed at the top dead center and the bottom dead center, and the speed is slow near the top dead center and the bottom dead center, and the amount of change in volume per unit time is also small. It is small and has the maximum speed at each intermediate point when moving from bottom dead center to top dead center and from top dead center to bottom dead center, and the maximum amount of volume change due to piston movement per unit time .

On the other hand, the expansion cylinder 33 has an expansion cylinder block 40 fixed by bolts or the like above the compression cylinder 32, and an expansion piston 42 provided with a piston ring 35 'in the space of the expansion cylinder block 40. Slides back and forth, and the upper part (expansion chamber) of this space is the low-temperature chamber 41, in which the working gas expands to a low temperature. One end of an expansion piston rod 43 is fixed to the expansion piston 42, and the other end of the expansion piston rod 43 extends through an oil seal 44 and is connected to the cross guide head 29. The expansion piston 42 is a compression piston 3
It moves ahead 90 degrees ahead of 6. The expansion cylinder block 40 is provided with a manifold 45 through which the working gas flows in and out of the compression chamber of the compression cylinder 32 from below in the drawing.
6. The animal cooler 47 and the passage 48 to the high temperature chamber 37 are annularly arranged so as to sequentially communicate with each other. Near the upper end of the compression cylinder block 34, the high temperature chamber 37 and the manifold 4
5, a communication hole 49 is formed to communicate the high temperature chamber 37 (compression chamber) and the low temperature chamber 41 (expansion chamber).
Communication hole 49, manifold 45, heat exchanger 46 for heat radiation,
It is configured so as to sequentially communicate with each other via the cooler 47 and the passage 48. The passage 48 may be provided with a heat exchanger in this portion to serve as a cooler.

FIG. 8 shows a connection state between the expansion cylinder block 40 and the compression cylinder block 34. Generally, the materials of the expansion cylinder block 40 and the compression cylinder block 34 are different. For example, if the material of the expansion cylinder block 40 is stainless steel (SUS304), the material of the compression cylinder block 34 is iron (FC250).
Etc.). In this embodiment, between the expansion cylinder block 40 and the compression cylinder block 34, a ring member (packing) 101 having extremely low thermal conductivity such as ceramics is used.
Is interposed. Thereby, the compression cylinder block 34
(For example, 90-100 ° C.) to the expansion cylinder block 4
Since the heat conduction to 0 (for example, -80 ° C.) can be reduced, the refrigeration capacity can be improved. In addition,
When the ring member 101 is interposed, as shown in FIG.
An annular recess may be formed in the compression cylinder block 34, and the ring member 101 may be interposed in the annular recess. It is possible to provide an annular recess in the expansion cylinder block 40. Of course, an annular recess may be provided in each of the compression cylinder block 34 and the expansion cylinder block 40.

The heat radiating heat exchanger 46 is an annular type heat exchanger, for example, a shell-and-tube heat exchanger 50 (a working gas flows into an annular heat exchange chamber 51) as shown in FIGS. A heat exchanger that cools working gas by flowing cooling water into the heat exchange chamber 51 by providing a plurality of tubes 52 in the axial direction may be used. FIG. 3 is a sectional view taken along the line AA in FIG. Alternatively, as shown in FIG. 4, an annular jacket 53 is provided around the annular working gas flow path.
May be arranged, and cooling water may flow in the jacket 53 to cool the working gas.

The heat-exchanging heat exchanger 46 is connected to the cooling water pipe 5.
The cooling water is circulated by being connected to the radiator 55 via the cooling water pump 4 and the cooling water pump P 1, and the cooling water heated by exchanging heat in the radiating heat exchanger 46 is cooled by the cooling fan of the radiator 55. . The cooling water pump P1 is provided in a cooling water pipe 54 connecting the lower end K1 of the radiator 55 and the lower end K4 of the heat exchanger 46. Accordingly, even if air enters the cooling water pipe 54 for some reason during the operation of the Stirling refrigerator 3, the air is supplied to the cooling water pump P.
Since it will be located higher than the entrance K2 of 1
It is possible to suppress air biting of the cooling water pump P1.

At this time, the inlet K2 of the cooling water pump P1
Is provided at a position appropriately lower than K1, the outlet K3 of the cooling water pump P1 is provided at a position appropriately lower than K4, and
If K1 is provided so as to be lower than K4, the air can be substantially prevented from entering the cooling water pump P1, so that the cooling water pump P1 can surely suppress the air bite. it can. The cooling water pipe 54
The pipe is branched and connected, and a water reservoir tank 57 is connected to the pipe via a reservoir valve 56. The radiator 55 is connected to an air vent 58 and a drain valve 59. The cooling head 4 is formed above the expansion cylinder block 40. For example, as shown in FIGS. 5 and 6, the cooling head 4 is provided with a top wall 62 having a large thickness at the top of the expansion cylinder block 40, and a heat exchange channel 63 for a cryogen is formed on the top wall 62. Configuration. Alternatively, as shown in FIG. 4, a structure may be adopted in which a jacket wall 64 is provided on the top of the expansion cylinder block 40, and a cold and hot refrigerant flows through the jacket wall 64.

As described above, the cooling head 4 is connected to the cold heat utilization device 8 through the cold refrigerant pipe 5 and the cold refrigerant pump P2, and circulates the cold refrigerant. A suction tank 65 is provided in the cold refrigerant line 5.
A cold / hot refrigerant reservoir tank 67 is connected to the suction tank 65 via a reservoir valve 66. A drain valve 68 is connected to the suction tank 65. An air vent 69 is connected to the cold / hot refrigerant line 5. Ethyl alcohol, HFE, PFC, nitrogen, helium, and the like are used as the cold refrigerant.

Next, the operation of the Stirling cooling device 1 according to the above embodiment of the present invention will be described.

The motor 16 drives the crankshaft 23
Rotates in the forward direction, and the crank 25 in the crank chamber 15
a and 25b rotate 90 degrees out of phase. The cross guide heads 28, 29 attached to the ends of the connecting rods 26, 27 reciprocate in the cross guide liners 30, 31 via connecting rods 26, 27 rotatably connected to the crank portions 25a, 25b. Slide. Each of the cross guide heads 28 and 29 has a compression piston rod 3
The compression piston 36 and the expansion piston 42 connected via the expansion piston rod 8 and the expansion piston rod 43 reciprocate with a phase difference of 90 degrees from each other. While the expansion piston 42 moves slowly near the top dead center 90 degrees ahead, the compression piston 36 rapidly moves toward the top dead center near the middle to perform the compression operation of the working gas. The compressed working gas passes through the communication hole 49 and the manifold 45, and the heat exchanger 46 for heat radiation.
Flows into.

The working gas radiated to the cooling water in the heat radiating heat exchanger 46 is cooled by the cooler 47 and flows into the low temperature chamber 41 (expansion chamber) through the passage 48. Compression piston 36
Is moving slowly near the top dead center, the expansion piston 42 moves rapidly toward the bottom dead center, and the working gas flowing into the low temperature chamber 41 (expansion chamber) expands rapidly to generate cold heat. As a result, the top of the expansion cylinder block 40 in the cooling head 4 surrounding the expansion chamber is cooled to a low temperature. Then, the cooling head 4 cools the cold refrigerant circulating through the cold refrigerant pipe 5.

When the expansion piston 42 moves from the bottom dead center to the top dead center, the compression piston 36 moves from the intermediate position to the bottom dead center, and the working gas flows from the expansion chamber through the passage into the animal cooler 47. The cold heat of the working gas is stored in the animal cooler 47. The cold heat stored in the animal cooler 47 is reused to cool the working gas sent from the high-temperature chamber 37 through the heat-radiating heat exchanger 46 again as described above. The cryogen cooled in the cooling head 4 is sent from the cryogen line 5 and the outlet plug 7 to a cryogen pipe in the cryogenic device 8 such as a freezer, for example. Performs a cooling action. In the cold utilization device 8, the cold refrigerant absorbs heat and performs a cooling action, is sent from the cold refrigerant pipe to the inlet plug 6, passes through the cold refrigerant pipe 5, returns to the cooling head 4, and is cooled there. You. in this way,
The cold refrigerant circulates between the cooling head 4 of the Stirling refrigerator 3 and the cold utilization device 8, and the cold refrigerant is cooled by the Stirling refrigerator 3, and this cold refrigerant acts as a cooling function in the cold utilization device 8. Hereinafter, the same cycle is repeated.

The cooling water exchanged in the heat-radiating heat exchanger 46 flows from the cooling-water pipe 54 to the radiator 55, where it is cooled by a cooling fan and circulated to the heat-radiating heat exchanger 46 again. At this time, even if air accumulates in the cooling water pipe 54 for some reason, the cooling water pump P1
Is provided between the lower end K1 of the heat exchanger 46 and the lower end K4 of the heat radiation heat exchanger 46, the air biting of the cooling water pump P1 can be suppressed, and the cooling water can be stably supplied to the heat radiation heat exchanger 46. It is possible to circulate. Therefore, it is possible to prevent the efficiency of the Stirling cooling device from decreasing.

On the other hand, in the Stirling cooling device, air may enter the cooling water circulation system including the cooling water piping 54 for some reason during operation. During the sealing process, air may be mixed into the cooling water pipe 54. In this embodiment, a method is proposed in which air is not mixed in the process of sealing the cooling water into the circulation path including the cooling water pipe 54.

FIG. 7 shows a cooling water charging method according to the present embodiment. That is, as a procedure according to the present embodiment, as shown in FIG. 7A, first, the cooling water pipe 54a on the suction side of the cooling water pump P1 is formed so as to be detachable, and each end of the cooling water pipe 54a thus made detachable. Connectors A and B for joints are provided in the section. Cooling water piping 54
In a state where each end of a is cut off, each end is submerged in a container 100 filled with water, and the cooling water pump P1 is operated. However, a certain amount of water is put into the cooling water pump P1 as priming water. The operation of the cooling water pump P1 causes the container 10 to enter the cooling water circulation system including the cooling water pipe 54.
0 cooling water is enclosed. In order to prevent air from being mixed in the process of filling the cooling water, the operation of the cooling water pump P1 is continued until no air (bubbles) appears in the water. Thereafter, as shown in FIG.
In the water, each end of the separated cooling water pipe 54a is connected by connectors A and B.

In this embodiment, during the process of sealing the cooling water into the cooling water pipe 54 during maintenance or the like, the cooling water pipe 5
Since no air is mixed into the cooling water 4, the cooling water pump P1 does not bite the air, and the cooling water can be circulated properly. Therefore, since the heat of the working gas sent from the compression chamber to the expansion chamber is sufficiently radiated, the refrigeration efficiency of the Stirling refrigerator can be improved.

Although the present invention has been described with reference to one embodiment, it is apparent that the present invention is not limited to this. For example, although the two-piston type Stirling refrigerator 3 is used in the above embodiment, it is needless to say that the present invention can be applied to other types of Stirling refrigerators 3 such as a displacer type.

[0034]

As described above, claims 1 and 2
In the described invention, an annular packing formed of a member having low thermal conductivity is interposed between the compression cylinder block and the expansion cylinder block, so that, for example, the compression cylinder block is made of iron, and the expansion cylinder block is Even if it is made of stainless steel, heat transfer from the compression chamber side to the expansion chamber side is suppressed, and the refrigeration capacity can be improved.

According to the third aspect of the present invention, the cooling water pipe on the suction side of the cooling water pump is disconnected, and each end of the separated cooling water pipe is submerged in the water of the same tank, and air is discharged into the water. Operate the cooling water pump until it runs out, fill the water into the circulation path, and then connect each end of the cooling water pipe separated in the water in the same tank. Since air is not mixed into the cooling water pipe in the process of charging the cooling water, the cooling water pump can be properly circulated without causing the cooling water pump to bite the air. Therefore, since the heat of the working gas sent from the compression chamber to the expansion chamber is sufficiently radiated, there is an effect that the refrigeration efficiency of the Stirling refrigerator can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a Stirling cooling device applied to an embodiment of the present invention.

FIG. 2 is a plan view illustrating an example of a heat radiation heat exchanger.

FIG. 3 is a sectional view taken along the line AA in FIG. 2;

FIG. 4 is a side sectional view illustrating another example of the cooling head.

FIG. 5 is a side sectional view illustrating an example of a cooling head.

FIG. 6 is a sectional view showing the cooling head of FIG. 5;

FIGS. 7A and 7B are diagrams showing an embodiment of the present invention, wherein a is a diagram showing a state in which a connector is detached and cooling water is sealed, and b is a diagram showing a state in which the connectors are connected.

FIG. 8 is a diagram showing a connection state between an expansion cylinder block and a compression cylinder block.

FIG. 9 is a diagram showing another example of FIG. 8;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Stirling cooling device 3 Stirling refrigerator 34 Compression cylinder block 36 Compression piston 37 High temperature chamber (compression chamber) 40 Expansion cylinder block 41 Low temperature chamber (expansion chamber) 42 Expansion piston 46 Container 100 Container 101 Ring member (packing) A, B Connector P1 Pump for cooling water

Claims (3)

[Claims] 1. A compression cylinder block, a compression piston that slides in the compression cylinder block and compresses a working gas in a compression chamber, an expansion cylinder block connected to the compression cylinder block, and an inside of the expansion cylinder block. The compression piston is reciprocated approximately 90 degrees out of phase with the compression piston to expand the working gas in the expansion chamber, and the compression chamber and the expansion chamber are connected to each other. It had a gas flow path connected back and forth, a heat-radiating heat exchanger connected to the gas flow path, and a cooling head provided around the expansion chamber and capable of connecting a cold heat utilization device. In the Stirling cooling device, an annular packing formed of a member having low thermal conductivity is interposed between the compression cylinder block and the expansion cylinder block. And a Stirling cooling device. 2. An annular recess is formed in a joint surface of the compression cylinder block and / or the expansion cylinder block, and the annular packing is mounted in the recess so that the compression cylinder block and the expansion cylinder block are separated from each other. The Stirling cooling device according to claim 1, wherein the Stirling cooling device is connected. 3. A compression piston for compressing the working gas in the compression chamber, an expansion piston for reciprocating out of phase with the compression piston by substantially 90 degrees to expand the working gas in the expansion chamber, A gas passage connecting the expansion chamber and connecting the working gas so as to move between them; a working gas which is provided in the gas passage and which has been compressed in the compression chamber and raised in temperature; It has a radiating heat exchanger for exchanging heat with water, a circulating system including a cooling water pipe for circulating cooling water through the radiating heat exchanger, and a cooling water pump connected to the cooling water pipe. In the cooling water filling method of the Stirling cooling device, the cooling water pipe on the suction side of the cooling water pump is disconnected, and each end of the separated cooling water pipe is submerged in the water of the same tank. Cool until no more A method for filling cooling water in a Stirling cooling device, characterized by operating a water pump to fill water into the circulation path, and connecting each end of a cooling water pipe separated in water in the same tank.