JP2001241795A - Structure of gas operating space of pulse tube type stirling refrigerating machine and pulse tube type stirling refrigerating machine using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and highly efficient refrigerating machine with low noise and vibration, components thereof and particularly a configuration and a structure of a gas operating space in a cryogenic refrigerating machine currently put to practical use. SOLUTION: In a structure of a gas operating space of a pulse tube type Stirling refrigerating machine and a pulse tube type Stirling refrigerating machine using the structure of the gas operating space, a single or a plurality of radiatots, a cold storage device, a cold head, a pulse tube, a rectifier or the like are connected between a gas compression space comprising two or four fixed pistons having inner parts cooled and two or four movable cylinders including expansible bellows and a gas expansion space comprising two or four fixed pistons and two or four movable cylinders. The movable cylindrs are driven by a linear motor to generate low temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas working space of a pulse tube type Stirling refrigerator, and more particularly, to a structure of a compression space portion and an expansion space portion of a working gas and a pulse tube type Stirling refrigerator using the same.

[0002]

2. Description of the Related Art Regarding this method, which is the object of the present invention, Japanese Patent No. 2706980 "Pulse tube refrigerator", Japanese Patent No. 2824946 "Adiabatic pulse tube refrigerator", and Patent No. 2943030 by the present applicant. No. "Pulse tube type Stirling refrigerator" and Japanese Patent Application Laid-Open No. 9-170552 "Opposed piston type compressor", and the technical paper of the present applicant, 1) Y. ISHIZAKI & E. ISHIZA
KI "Experimental Performance"
ce of Modified Pulse Tube
Refrigerator below 80K d
own 23K "International Cryo
cooler Conference, Nov. 171
9 (Santa Fe) 1992, 2) Y. ISHIZ
AKI & E. ISHIZAKI "PROTO TYP
EOF PULSE TUBE REFRIGERAT
OR FOR PRACTICAL USE "Cryo
genetic Engineering Confere
nce, July 12-16 (Albuquerqu
e) 1993, which is 23.5K (about minus 2
49.5 ° C.).

[0003]

However, in the cryogenic refrigerator currently in practical use, there is a great demand for higher efficiency, lower noise / vibration, and lower cost. A refrigerator that satisfies this and a constituent element thereof, particularly a configuration and a structure of a gas working space are expected.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides (1) a movable type including two or four fixed pistons whose inside is cooled and two or four telescopic bellows. One or more gas compression spaces between the gas compression space composed of cylinders and the gas expansion space composed of two or four fixed pistons and their two or four movable cylinders The radiator, regenerator, cold head, pulse tube, rectifier, etc. are connected, and the movable cylinder is driven by a linear motor to generate low temperature. What you want to do.

[0005] Further, the volume change of the expansion space of one or more gases is driven by a linear motor with a phase difference earlier than that of the compression space, and a low temperature is generated by one or more cold heads. A structure that dissipates the heat of compression to the outside using at least one of a small pump, heat pipe, and thermosiphon to cool the inside of the fixed piston in the gas compression space with gas or liquid and remove the heat of gas compression. With the structure of the gas working space of the pulse tube type Stirling refrigerator having the above, further, utilizing the change of gas pressure generated in the crankcase by the left and right movement of the movable cylinder, the gas is discharged from the discharge valve installed in the crankcase. It leads outside to dissipate heat, and then leads to contact with the movable cylinder in the gas expansion space, cools it, and transfers this gas to the compression space. Back from the suction valve installed in crankcase in the crankcase is intended to do attempted to solve the structure of a gas working space configuration the pulse tube type Stirling refrigerator to cool the moving cylinders and other components such.

Further, a plurality of gas compression spaces and expansion spaces, or a plurality of gas compression spaces and expansion spaces are formed by bellows or cylindrical movable cylinders having different or identical diameters. In addition, the horizontal center axis of the reciprocating movable plate is displaced between the movable plate and the fixed piston or between the movable plate and the crankcase, and does not contact the fixed piston. Install proximity switches, position sensors, bearings,
It is an object of the present invention to solve the problem by a structure of a gas working space of a pulse tube type Stirling refrigerator characterized in that the operation is controlled by an electro-system including a computer.

Further, a gas port in a gas compression space portion,
Due to the structure of the gas working space of the pulse tube type Stirling refrigerator, wherein a suction valve and a discharge valve are respectively installed at the gas ports of the crankcase of the gas compression space and the small gas expansion space, A pulse tube type Stirling refrigerator characterized by using the structure of the gas working space is to be solved.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a gas compression space and an expansion space of a pulse tube type Stirling refrigerator.
Fixed pistons or 4 fixed pistons and 8 large and small
One or four movable cylinders (including telescopic bellows and cylinders) are driven by a rotor of a linear motor and a stator attached to a crankcase to form a gas compression space and an expansion space. A radiator, regenerator, cold head, pulse tube, valve, etc. are connected between the fixed piston gas compression space and the small gas expansion space to cool the inside by arranging them symmetrically. The volume change of the gas expansion space is performed at a phase difference of 40 ° ± 30 ° faster than that of the gas compression space to generate low temperature in one or more cold heads with a simple device configuration / structure. The pulse tube type Stirling refrigerator has a structure of a gas compression space portion and an expansion space portion which is designed to perform with low mechanical vibration, low noise, and high efficiency (high coefficient of performance).

The details of the present invention will be described below. FIG. 1 shows a flow path system for components of a pulse tube type Stirling refrigerator and a working fluid (hereinafter, referred to as gas). This gas includes helium, hydrogen, argon, nitrogen, air and other gases and mixed gases. The average pressure of the gas is about 1 Mpa
2.5 MPa (10 to 25 atm). A gas compression space 1 is formed by a piston 2 and a cylinder 3. When the piston is driven up and down by a piston drive mechanism (not shown), the gas fluctuates at a compression ratio of about 2. This 1 is connected from a radiator 5, an insulated regenerator 6, a cold head 7, and a pulse tube 8 to a small gas 10 at almost normal temperature via a pipe. 9 is a piston ring. 10 is a cylinder 11, a small piston 12,
The piston ring 9 is driven by the rod 13 with a certain phase difference α from that of the piston ring 9 to change the volume. The volume of the expansion space is changed 10 to 90 degrees earlier than the compression space. (When the phase difference control between the compression space portion and the expansion space portion is impossible by the drive control system of the linear motor, a capillary, a needle valve, a suction / discharge valve, etc. are provided between the pulse tube 8 and the expansion space portion 10. A configured flow / phase control mechanism is required.)

In the embodiment, the optimum phase angle α is the required freezing temperature T, the frequency f, the average operating pressure Pm of the gas, the dead volume inside the device, the compression space and the expansion space, the gas from the radiator and the pulse tube. Pipe length L, volume Vc of compression space
And the volume ratio β of the expansion space Ve. FIGS. 7 (a) and 7 (b) show the relationship between the α curve and β and COP (coefficient of performance) by the experiment.

In this experiment, T = 80K, α = about 40
Degree, f = 3.83, average operating pressure P of working gas (He)
m = 1.5 MPa, volume ratio β = Vc / Ve = 8.09 between the compression space Vc and the expansion space Ve, and the length of each of the pipes from the compressor to the regenerator and the pulse tube and the expansion space L = 100 cm, optimal α is 36 degrees and COP is 0.
035. That is, in order to obtain a refrigeration output of 10 W at 80 K, power consumption (electric power of a motor or the like) of about 286 W is required. In this experiment, since the volume of the compression space and the expansion space was varied by the piston / crankshaft method, mechanical loss was large and COP was low. The minimum temperature reached 23.5K at α of about 20 degrees. However, COP (Coefficient of Perform)
anc) = Refrigeration output (W) / Power consumption (W) COP = 10W / 286W = 0.035

The present invention relates to the structure and structure of a gas compression space and an expansion space at almost normal temperature of the pulse tube type Stirling refrigerator, and a displacer which operates at a low temperature like a Stirling refrigerator. This method does not require an expansion piston. The basic structure is that in the opposed-piston type compressor disclosed in Japanese Patent Application Laid-Open No. 9-170552 of the applicant, three gas compression spaces are formed by two convex movable pistons, two convex fixed pistons, and one fixed cylinder. The compressor is characterized by obtaining a good dynamic balance by improving the structure of the compressor with low vibration, low noise and high efficiency.

FIG. 2 is a cross-sectional view of the gas compression space of the pulse tube type Stirling refrigerator according to the present invention. This is a structure in which two compression spaces are provided, each of which has a variable volume in the same phase as one, and is driven by a linear motor as one compression space. A fixed piston 17-cooled from the inside of the piston is provided on a main flange portion 16 at the center of the crankcase 15 to which a number of radiation fins (not shown) are attached.
1 and 17-2, the inside of which is filled with a cooling body, for example, alcohol, water, antifreeze, other liquid, or a gas similar to the working gas, to the cooling body inlet 18, the cooling body branch 1
9-1 and 19-2 and the cooling body suction ports 20-1 and 20-2 are put in, and the inside of the fixed piston is cooled and goes out from the cooling body outlet 21 to the outside. This cooling body is circulated by a cooling system such as a radiator or a pump (not shown) to radiate heat outside. It is also possible to dissipate heat shared with the gas in the crankcase 15 and the heat exchanger.

For this reason, the fixed pistons 17-1 and 17-2
The outer surface of the gas with respect to the compression space portions 22-1, 22-1 is always cooled. Therefore, the rotors 23-1 and 23-2 (magnet type or coil type) of the linear motor are provided with bellows 24-1 and 24-2 attached to the movable plates 26-1 and 26-1, and a stator 25-. 1, 25
-2 and compressed by the gas ports 27-1 and 27-2
The temperature of the gas coming out of the gas port 29 will not be too high. Therefore, the isothermal compression efficiency is high and the room temperature is 293.
At the time of K, it is about 320K at the gas port 29. This corresponds to the position 29 in FIG. 1, and the heat load of the radiator 5 can be small.

Movable plates 26-1, 26-2, bellows 24
Crankcase 1 by left and right movement of -1, 24-2
The pressure of the gas inside 15-1, 15-2 slightly fluctuates. Using this dynamic pressure, this gas is supplied to the gas port 47-1,
47-2, the heat is guided from the discharge valve 31 to the outside of the crankcase, radiated and cooled, and the suction valves 30-1 and 30-2 installed on the flat flanges 32-1 and 32-2 are 15-1 in the crankcase from the suction valves. Return to 15-2. For this reason, crankcase 1
The bellows 24-1 and 24-2, the movable plate, the components of the linear motor, and the like, which are inside 5, are always cooled. Although not shown,
The installation of the cooling / radiating system leads to the improvement of the durability of the expanding and contracting bellows and the efficiency of the linear motor. Use the same gas as the working fluid. 15- in the crankcase
After the gases 1 and 15-2 are radiated to the outside, they are cooled in the crankcase in the expansion space shown in FIG.
-2 suction valve.

The compression space 22- in FIG.
Numerals 1 and 22-2 indicate the maximum volumes because the movable plates 26-1 and 26-2 are at the bottom dead center, respectively, and in FIG. Although not shown, between the movable plates 26-1 and 26-2 and the main flange portion 16 and the flat flanges 32-1 and 32-2, a rod-shaped ferrite attached to the movable plate and detecting and controlling the position thereof is provided. , Iron, 68
-1, 68-2, coils 69-1, 69-2, etc., and springs 70-1, 70-2 set in a compressed or tensioned state for smoothly operating the movable plate,
Although not shown, there is a damper for adjusting the damping. Furthermore, when the movable cylinder reciprocates left and right, bearings and the like are installed so that the center of the fixed piston does not deviate and come into contact with the movable piston, and one of the methods 71-1, 71-2 has a spring function for regulating the position of the movable plate. A large number of holes are formed to prevent windage loss due to phosphor bronze, stainless steel, etc., and one or a plurality of corrugated diaphragms are provided. The movable plates 26-1 and 26-2 have screws 72-1. 71
It is fixed to the crankcase with screws (not shown). These are applied to all configurations and structures described later.

The structure of the gas compression space portion of this system is such that the movable plates 26-1 and 26-2 are provided during the gas compression process.
Move toward the main flange 16, which is the center of the crankcase 15, and move in the directions of the opposite flat flanges 32-1 and 32-2 during the expansion / equal volume stroke, so that the occurrence of mechanical vibration is extremely small.

FIG. 3 shows two expansion spaces (33-1, 33-2) of the expansion space 10 composed of 11, 12, and 13 shown in FIG. The linear motors (stators 34-1 and 34-2, rotors 35-1 and 35-2) are additionally provided and driven to form one expansion space. The structure is substantially the same as the configuration and structure of the gas compression space shown in FIG. The gas whose volume is variable in the expansion spaces 33-1 and 33-2 passes through the gas ports 36-1 and 36-2 to the gas inlet / outlet 37. Three
Reference numeral 7 corresponds to a position 37 in FIG. 1 and is connected to the pulse tube 8 via a pipe.

The rotor 3 is attached to the movable plates 39-1 and 39-2.
5-1 and 35-2 and bellows 38-1 and 38-2 are attached. The movable plates 39-1 and 39-2, the central portion 43 of the crankcase 44, and the flat flanges 39-1 and 39-1
-2, and between the fixed piston, the precise position of the movable plate in order to reduce the dead volume and prevent collision with the fixed piston, in order to reduce the dead volume and prevent collision with the fixed piston in the expansion space. Control is provided with a position sensor, a damper adjuster, and the like (not shown) as well as the springs 40-1 and 40-2, as well as the configuration and structure of the compression unit in FIG.

Reference numerals 41-1 and 41-2 denote expansion space portions 33-.
Bellows 3 due to temperature drop during expansion of gas at 1, 33-2
In order to prevent overcooling of the crankcases 8-1 and 38-2, the gas whose temperature has increased in the crankcase 15 in the compression space shown in FIG. Heat bellows 45-1 and 45-2,
The discharge valve 42 returns to the suction valves 30-1 and 30-2. In other words, this circulating gas cools the bellows, linear motor, etc. in the crankcase that constitutes the compression space, radiates the hot gas to a liquid such as water or the atmosphere through a heat exchanger, and then expands. It is configured to cool in the space and return it into the crankcase of the compression space, which is done continuously.

In the case of a refrigerator with a cold head 7 (FIG. 1) and a refrigeration output of 80 K and several tens of watts, depending on the operating conditions, the entire structure of the expansion space is prevented from being supercooled (273 K or less). Therefore, it is preferable from the viewpoint of durability of the bellows 38-1 and 38-2 that the fixed pistons 46-1 and 46-2 be hollowed out and heated like the fixed pistons in FIG. In (a), the expansion spaces 33-1 and 33-2 are used.
Indicates the bottom dead center (maximum volume) in the same phase, and (b) indicates the top dead center (minimum volume).

The low temperature is generated by two linear motor rotors 23-2 attached to the movable plates 26-1, 26-2, 39-1 and 39-2 in the compression space portion and the expansion space portion, respectively.
1, 23-2, 39-1, and 39-2, and an electronic circuit system including a computer (not shown) for position control and frequency control of the movable plate. The working fluid to be enclosed is mainly helium gas, and the pressure is 1 Mp to 2.5.
Mpa (about 10-25 atm). The expansion spaces 33-1 and 33-2 are driven by an electronic system such that the phase angle α is advanced from 10 degrees to 90 degrees more than the change in the variable volume of the compression spaces 22-1 and 22-2.

FIG. 7 shows the experimental values.
Depends on the required freezing temperature, and decreases as the required temperature decreases. Pressure is 1MPa or less, β is 8 ~ 1
2 is better.

In FIG. 1, the gas port 2 in the expansion space shown in FIG.
9, the gas which is theoretically isothermally compressed is radiated by the radiator 5, and is cooled isosterically by the regenerator 6, and is expanded from the cold head 7, the pulse tube 8, and the gas inlet / outlet 37 through the expansion portions 33-1 and 33.
-2 and expands isothermally. Next, the low temperature gas flows in the opposite direction and returns to the compression space portion in an equal volume. This process is repeated to generate a low temperature, and the cold head 7 cools the material to be cooled. The refrigeration output is determined by the gas pressure, the volume of the compression space and the expansion space, and the operating frequency.

The optimum phase angle α is the required refrigeration temperature T, frequency f, average operating pressure of gas Pm, dead volume inside the apparatus, length of the gas pipe from the compression space and expansion space, the radiator and the pulse tube. L, the volume V of the compression space, the volume ratio β between the compression space and the expansion space, and the like. FIG. 7 (a) shows the relationship between the α curve and β and COP by experiment.
As shown in (b), in the experiment, the COP was 0.0K at 80K.
35.

In the system of the present invention, in which the volumes of the two compression spaces and the two expansion spaces are varied by driving the linear motor, respectively, the fixed piston is cooled from the inside, so that the isothermal compression in the gas compression process is performed. Since the efficiency is high, the number of moving parts is small, and the weight is low, a COP of 0.04 or more can be expected from the improvement of electromagnetic and mechanical efficiency.

FIG. 4 is a flow diagram of a two-system Stirling type pulse tube refrigerator. The left is the same as FIG. 1. If the shape, structure, and heat load capacity of the radiator 48, the regenerator 49, the cold head 50, and the pulse tube 51 are the same, the cold heads 7 and 50 have a value of 7. Is obtained, and the COP is increased due to the improvement in mechanical efficiency. Further, if the cold storage capacity of 6 is increased and the length of the pulse tube 8 is lengthened, and the refrigeration of the cold head 50 is used for cooling 6 and 8 and a heat radiation preventing plate (not shown), for example, the cold head 50 has 80K, 9 for 9K
It is easy to obtain ~ 15K.

3 and 4, the volumes of the compression space portion and the expansion space portion are each doubled, and when compared under the same operating conditions, the efficiency becomes higher and the COP at 80K becomes 0.0
Let's approach 5.

FIGS. 5 and 6 show the flow path system shown in FIG. 4, in which eight fixed pistons and eight movable cylinders are used to form four compression spaces and four expansion spaces. 1 is a configuration and structure of a gas compression space portion and an expansion space portion of a double-acting pulse tube type Stirling refrigerator. Compression space 2
The maximum volumes of 2-1 and 22-2 are the expansion spaces 33-1 and 3-1, respectively.
It is several times (about 4 to 9 times) larger than 3-2.

FIG. 5 shows the compression units 22-1 and 22 shown in FIG.
The movable cylinders 51-1 and 51-2 are also added to the opposite sides of the movable plates 26-1 and 26-2 forming the second unit 2, and the fixed pistons 52-1 and 52-2 are installed to set the compression space 53-1. ,
53-2, and the gas is supplied to gas ports 54-1 and 54-.
2, and both are unified by the radiator 48 of FIG. In FIG. 5A, the compression spaces 22-1 and 22-2 are used.
Is the maximum volume, and the compression space 53-1 on the opposite side,
53-2 is the minimum volume. (B) The figure shows the movable plate 26-
The right half when 1, 26-2 moves in the direction of the main flange 16 is shown, but the compression spaces 53-1 and 53-2 have the maximum volumes.

The rotors 23-1 and 23 of the linear motor attached to the movable plates 26-1 and 26-2, respectively.
-2 and the stators 25-1, 25-2, the respective compression spaces 53-1, 53-2, 22-1, 23-
2, the drive system is the same as the system of FIG. Parts in the crankcases 15-1 and 15-2 are cooled by the cooled gas from the suction valves 30-1 and 30-2, and then come out of the crankcase 15 from the discharge valve 31 to the atmosphere or the cooling fluid. Etc., or is cooled and circulated in the crankcase in the expansion space.

The fixed pistons 17-1 and 17-2,
The same cooling fluid 18 and 19 are provided inside 52-and 52-2.
-1, 19-2 and 18-1, 19-3 and 18-2,
Enter from 19-4, cool the inside of the fixed piston,
1, 20-2 to 21, 22-3 to 21-1, 22-
Exit from 4 to 21-2. These 21, 21-1, 21-
Fluids from 2 are combined into one flow path, air, cooling fluid,
For example, heat is radiated to water and cooled and circulated by a small pump. Further, these cooling methods are the same as the cooling method of the compression space portion shown in FIG. 2 utilizing cold in the expansion space portion.

FIG. 6 shows the construction and structure of the expansion space shown in FIG. 3, in which a movable plate is provided with rotors 35-1 and 35-2 in addition to the two expansion spaces 33-1 and 33-2. 39-
Movable cylinders 56-1, 5
6-2, and expansion pistons 56-1 and 56-2, in which the fixed pistons 57-1 and 57-2 are installed and the volume is variable in phase.
This is the configuration and structure for forming the individual. In this structure, there are two expansion spaces that are variable in volume with a phase of 180 degrees, and are driven in pairs with the compression unit of FIG. 5 described above to generate low temperature.

The expansion spaces 33-1 and 33-2 are provided with the gas ports 3
7, the expansion space portions 56-1 and 56-2 are provided with gas ports 55-1.
And 55-2 together conduct the pulse tube 51 of FIG. The operation is performed by adding gas ports 29, 54-1 and 54-2 from the compression space section in FIG. 5 and gas ports 55-1 and 55- from the expansion space section in FIG. 2 are connected to each other and driven by linear motors in an electronic system (not shown) so that the volume of the expansion space can be changed faster than that of the compression space. There are many phase angle parameters that are 10 to 90 degrees faster and maximize the efficiency of low temperature production.

The movable plates 39-1 and 39-2 and the flanges 58-1 and 58-2 and the main flange are provided between the movable plates 39-1 and 39-2 and the main flanges.
The springs 40-1 and 40-40 reduce the dead volume of the expansion space and smoothly change the volume of the expansion space.
Although not shown, a position sensor for the movable plate, a proximity switch, a mechanism for preventing the movable plate from colliding with the fixed piston, and the like are provided. These mechanisms are also incorporated in the devices shown in FIGS. 2, 3, 5 and 6, respectively, and are an electronic drive system including a computer (not shown) for controlling the position of the movable plate and controlling the operating frequency. Is performed.

If the gas in the crankcases of 45-1 and 45-2 is too cold (273K or less),
The gas from the discharge valve 42 is supplied to the fixed piston 17- in FIG.
1, 17-2, 52-1 and 52-2 are cooled, and the temperature of the fluid is increased through a heat exchanger (not shown) and returned from the suction valves 41-1 and 42-2. To a suitable temperature.

This method is the same in the case of the expansion space shown in FIG. 3, and in the case of supercooling also in this method, similarly to the fixed piston in the gas compression space shown in FIGS. 2 and 5, FIG. It is also possible to adopt a structure in which the inside of the piston is heated. Also, 29, 54-1 and 54 in FIGS.
-2, although not shown between the compression space portion and the inside of the crankcase, a small suction valve including a filter and a discharge port for preventing pressure and fluid contamination of the main flow path system such as a cold head and a regenerator. A fluid control mechanism including a valve and a needle valve is connected.

FIG. 7 shows the experimental values of the gas compression section and the expansion space section using an ordinary piston / cylinder 5). The structure and structure of the gas compression space section and the expansion space section of the present invention are practically used. Obviously, the COP will be higher and the lowest temperature will be lower.

FIG. 8 (a) shows a right half of a cut surface of a structure and a structure in which four large and small fixed pistons are provided with two large and small compression spaces. Movable plate 59-1 and fixed piston 71-
1, a large gas compression space part 24-1 is formed, and a small space part 22-1 is formed with the fixed piston 62-1 on the back surface thereof. b) The figure shows large and small 2 on both sides of the movable plate 63-1 instead of the movable cylinder of the bellows.
The right half of the embodiment in which two cylindrical cylinders 64-1 and 65-1 are attached together with the linear motor rotor 23-1 is shown.

Reference numeral 66 denotes a piston ring, which generates wear powder due to friction with the large and small cylindrical cylinders, generates decomposition gas, and gradually deteriorates the performance of the refrigerator, which hinders long-term operation. Cause. For this reason, a labyrinth seal is applied to the fixed piston, or the large and small fixed piston and the cylindrical cylinder, in which the performance is stable because the fixed piston and the movable cylinder do not contact each other. All other black circles are fixed O-rings for sealing. 24-1, 24-2, 45
Although not shown, the suction valves such as -1, 45-2 and 31 and 42 are connected to a radiator, a small pump or the like by piping. In addition, if a discharge valve and a suction valve are respectively installed in the gas port 69 and the gas port 68-1 and not shown but in the left 68-2, as in the case of the applicant's patent 4), the two-stage compression type non-lubricating It is clear that a compressor can be constructed.

Regarding the durability of the structure of the present invention, it was found that when the operating frequency was 4 Hz, the structure could endure continuous operation for about 4 years. Recent advances in bellows manufacturing technology have been remarkable.
In the present invention, the operating frequency is set to 4
Hz, the bellows expands and contracts in one year is 4Hz ×
3600 / sec × 24Hr × 365 / year = 1.
It was 26 × 10 ⁸ times, and when the life was 5 × 10 ⁸ times, it was found that the durability was about 4 years. If the operating frequency becomes 2 Hz, durability of about 8 years can be obtained.

As described above, the structure of the gas compression space portion and the expansion space portion of the pulse tube type Stirling refrigerator of the present invention can be of three types a), b) and c). There is. An electronics system including a drive and control computer is required separately for all three types.

[0043]

The effects of the present invention will be described below. a) The structure of the refrigeration cycle, in which two compression spaces and two expansion spaces are combined, enables it to be used for a wide range of applications up to the 50K range, and is optimal for maximizing refrigerator efficiency with respect to refrigeration temperature. Easy setting of operating conditions. (FIG. 1, FIG. 2, FIG. 3) b) The structure in which two sets of refrigeration cycles are combined with four compression spaces and four expansion spaces is a double-acting type, so that extremely low vibration is achieved.
It has high output and high efficiency, and can generate low temperature up to 10K region. (FIGS. 4, 5, and 6) c) By a combined cycle configuration using two sets of the refrigeration cycle structure of a) in which two compression space parts and two expansion space parts are made into one set. Higher output and higher efficiency can be expected. (Second
FIG. 3, FIG. 3 and FIG. 4) d) The configuration of the refrigeration cycle having a structure in which two sets of refrigeration cycles b) with four compression spaces and four expansion spaces are combined with a) is as follows. More stable high output and high efficiency can be expected.

E) As shown in FIG. 8 (a), a J-T cycle is constituted by a two-stage type non-lubricated compressor having a structure in which four large and small fixed pistons and two large and small compression spaces are provided. A)
-D) can be manufactured in various combinations in combination with any one of the above-mentioned items (a) to (d).
And e) are the same or Air, Ar, N ₂ , Ne, H ₂ , and H, respectively, according to the required refrigeration temperature and refrigeration output.
It is possible to use different gases such as e and a mixed gas. f) The structure of the compression space portion and the expansion space portion of the present invention has a simple structure and a small number of parts, and since there are many identical parts, a lightweight and compact refrigerator can be provided at low cost. g) Since a large compression space portion and a small expansion space portion can be formed on both surfaces of the movable plate, a refrigerator or a lubrication-free compressor composed of one or more sets can be provided at low cost.

The structure and structure of the gas compression space and the expansion space of the pulse tube type Stirling refrigerator according to the present invention are further summarized as follows: (1) Two or four compression spaces and expansions The configuration and structure of the space are symmetrically arranged with respect to the center of the device, and the changes in the gas strokes are the same with respect to the center of the device or the same in the outward direction. The occurrence of mechanical vibrations is extremely small. (2) Since expansion work (ideally, isothermal expansion work) in the gas expansion process is performed on the movable plates 24-1 and 24-2 to which the linear motor rotor is attached, power is recovered and the linear motor A pulse tube type Stirling refrigerator with low power consumption and high efficiency can be provided.

(3) Two or four sets of parts arranged symmetrically with respect to the center of the apparatus have the same shape and the same weight, so that dynamic balance can be easily maintained, and therefore, mechanical vibration is generated. Is extremely small. (4) Since the number of parts is small and there are many common parts, it is easy to assemble, and a lightweight, compact, low-weight, low-cost refrigerator can be manufactured, and improvement in reliability can be expected. (5) The fixed piston and the movable cylinder (bellows) are not in contact with each other, and there is no sliding like a normal piston / cylinder. It does not degrade the refrigeration performance. (6) The inside of the crankcase, which becomes high in temperature due to the generated heat, uses the dynamic pressure of the gas in the crankcase generated by the reciprocating motion of the movable plate and the movable cylinder driven by the linear motor, and uses the dynamic pressure of the gas in the crankcase. Since a circulating cooling system in which heat is radiated and cooled outside and introduced into the crankcase from the suction valve is adopted, bellows and other parts are cooled and durability is improved.

(7) Since the outer surface of the fixed piston in the gas compression space is always cooled by the cooling system circulating from the inside, the isothermal compression efficiency in the gas compression process increases, and The efficiency of the pulse tube type Stirling refrigerator employing the structure is increased. (8) If a discharge valve and a suction valve are installed at each gas port, a double-acting or two-stage compression type non-lubricated compressor is obtained. As with the “opposed piston type compressor” of the applicant's patent 4), Low vibration,
A highly efficient and durable compressor can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing components of a pulse tube type Stirling refrigerator of the present invention and a flow path system of a working fluid. Configuration and structure of gas compression space and expansion space

FIG. 2 is a cross-sectional view of a gas compression space of the pulse tube type Stirling refrigerator of the present invention in a lateral direction.

FIG. 3 is a sectional view of a gas expansion space of the pulse tube type Stirling refrigerator of the present invention.

FIG. 4 shows a pulse tube type Stirling refrigerator according to the present invention.
It is a figure which shows the flow-path system which combined system.

FIG. 5 is a cutaway view of one example of a pulse tube Stirling refrigerator of the present invention having four compression spaces and four expansion spaces.

FIG. 6 is a cross-sectional view of another example of the pulse tube Stirling refrigerator of the present invention having four compression spaces and four expansion spaces.

FIG. 7 is a view showing an experimental result by a pulse tube type Stirling refrigerator of the present invention.

FIG. 8 is a sectional view of a third example of a pulse tube type Stirling refrigerator of the present invention having two large and small compression spaces and using a linear motor.

[Explanation of symbols]

1 Compression space, 2 pistons, 3 cylinders, 4
Piston rod, 5 radiator, regenerator, 7 cold head, 8 pulse tube, 9 piston ring, 10 working gas, 1
1 cylinder, 12 piston, 13 piston rod, 15 crankcase, 16 main flange, 17
-1, 17-2 fixed piston, 18 cooling body inlet, 1
9-1, 19-2 Cooling body branch port, 20-1, 20-2
Cooling body inlet, 21 Cooling body outlet, 22-1, 22-
2 compression space, 23-1, 23-2 rotor, 24
1, 24-2 Bellows, 25-1, 25-2 Stator, 27-1, 27-2 Gas port, 29 Gas port, 3
0-1, 30-2 suction valve, 68-168-2 rod-shaped ferrite, 69-1, 69-2 coil, 70-1, 7
0-2 Spring.

Claims (8)

[Claims] 1. A gas compression space comprising two or four fixed pistons whose interior is cooled and a movable cylinder including two or four telescopic bellows, and two or four gas compression spaces. One or more radiators, regenerators, cold heads, cold tubes, pulse tubes, rectifiers, etc. are connected between the two fixed pistons and the gas expansion space composed of two or four movable cylinders The structure of the gas working space of the pulse tube type Stirling refrigerator characterized in that the movable cylinder is driven by a linear motor to generate a low temperature. 2. The method according to claim 1, wherein a change in volume of the expansion space of one or more gases is driven by a linear motor with a phase difference earlier than that of the compression space, and a low temperature is generated by one or more cold heads. Item 2. The structure of the gas working space of the pulse tube type Stirling refrigerator according to item 1. 3. The heat of compression is externally reduced using at least one of a small pump, a heat pipe, and a thermosiphon so as to remove the heat of compression of the gas by cooling the inside of the fixed piston in the compression space of the large gas with gas or liquid. The structure of the gas working space of the pulse tube type Stirling refrigerator according to claim 1, wherein the gas working space has a structure to radiate heat. 4. Use of a change in gas pressure generated in a crankcase due to left and right movements of a movable cylinder, guides the gas to the outside from a discharge valve installed in the crankcase, and dissipates heat. This gas is cooled by guiding it into contact with the movable cylinder, and the gas is returned into the crankcase from the suction valve installed in the crankcase in the compression space to cool the movable cylinder and other parts. The structure of the gas working space of the pulse tube type Stirling refrigerator according to claim 1, characterized in that: 5. A plurality of gas compression space portions and expansion space portions, or a plurality of gas compression space portions and expansion space portions are formed by bellows having different diameters or the same diameter or cylindrical movable cylinders. The structure of the gas working space of the pulse tube type Stirling refrigerator according to claim 1, wherein a plurality of the gas working spaces are combined. 6. A proximity switch, a position sensor, and a bearing in a movable plate and a fixed piston, or between a movable plate and a crankcase, so that a horizontal center axis of a reciprocating movable plate does not contact the fixed piston. The structure of the gas working space of the pulse tube type Stirling refrigerator according to any one of claims 1 to 5, wherein an operation is controlled by an electro-system including a computer. 7. A suction valve and a discharge valve are respectively provided at a gas port of a gas compression space portion and a gas port of a crankcase of a gas compression space portion and a small gas expansion space portion. Item 7. The structure of the gas working space of the pulse tube type Stirling refrigerator according to any one of Items 1 to 6. 8. A pulse tube type Stirling refrigerator using the structure of the gas working space according to any one of claims 1 to 7.