CN2811865Y - Air-reservoir-free high-frequency pulse tube refrigerator - Google Patents

Abstract

The utility model relates to a high-frequency pulse tube refrigerator without an air store, which comprises a high-frequency pressure wave generator and a pulse tube refrigerator. The pulse tube refrigerator includes a regenerator, a pulse tube and an inertia tube. The inertia tube is a long and thin tube, one end of which is connected to the heat exchanger at the hot end of the pulse tube, and the other end is closed; it can be a tube of equal diameter; or a long tube connected by tubes of different diameters; the inertia tube The cross-sectional area is smaller than that of the pulse tube, and the diameter ranges from 1 mm to 1 cm; the length of the inertial tube is 1/10 of the acoustic wavelength to 1 acoustic wavelength, and the specific value depends on the working gas, working temperature and working frequency. . The high-frequency pulse tube refrigerator without air storage provided by the utility model has a simple structure and does not need an air storage, thus overcoming all the defects caused by the existence of a large air storage in the existing high-frequency pulse tube refrigerators. The pressure wave phase leads the volume flow at the hot end of the pulse tube, so that the efficiency of the pulse tube refrigerator can be improved.

Description

A kind of no air reservoir type high frequency pulse tube cooler

Technical field

The utility model belongs to refrigeration and cryogenic technique field, specifically relates to the no air reservoir type high frequency pulse tube cooler that a kind of high-frequency pressure wave producer drives.

Background technology

Because high frequency pulse tube cooler need not to use the low temperature displacer in the sterlin refrigerator, brings the advantage of moving component under the no low temperature, thereby becomes the focus and emphasis in the small-sized Cryo Refrigerator research field of recent two decades.In order to obtain high refrigerating efficiency, need to realize leading volume flow one phase bit of pressure wave in the cool end heat exchanger position of pulse tube refrigerating machine.Because there is not displacer can come initiatively to realize this phase place, so must relying on the phase modulating mechanism that is positioned at the pulse tube hot junction, pulse tube refrigerating machine realizes phase adjusted, to guarantee in leading volume flow one phase bit of pulse tube hot junction realization pressure wave.Up to now, can realize that the leading high frequency pulse tube cooler that requires of this phase place has bidirection air intake type and inertia tube to add two kinds on air reservoir type.

Bidirection air intake type high frequency pulse tube cooler as shown in Figure 1, it is the pulse tube refrigerating machine 12 that a high-frequency pressure wave producer 1 drives, comprise: tube connector 2, regenerator hot end heat exchanger 3, regenerator 4, pulse tube cool end heat exchanger 5, pulse tube 6, the loop that pulse tube hot end heat exchanger 7 and bidirection air intake governor motion 9 form, it links to each other with air reservoir 8 by aperture governor motion 10.Because have the loop,, become the problem that is difficult to solution in the practical application so bring the direct current problem.

Inertia tube adds air reservoir type high frequency pulse tube cooler as shown in Figure 2, it is the pulse tube refrigerating machine 12 that a high-frequency pressure wave producer 1 drives, comprise: tube connector 2, regenerator hot end heat exchanger 3, regenerator 4, pulse tube cool end heat exchanger 5, pulse tube 6, pulse tube hot end heat exchanger 7, it links to each other with air reservoir 8 by inertia tube 11.The acoustics inertia that inertia tube adds air reservoir type high frequency pulse tube cooler dependence inertia tube to be provided is realized aforementioned phase place anticipation, and it can not bring the direct current problem.But in this structure, the hot junction of pulse tube is by one section elongated tubular, be that inertia tube links to each other with a big air reservoir, normally in the same system one of the pulse tube volume more than the magnitude, of the volume of this air reservoir with the boundary condition that provides a pressure oscillation to be almost equal to zero.The existence of this air reservoir is the tradition of continuing to use orifice pulse tube cooler fully, the shortcoming that it brings is: the size and the weight that have increased system, diameter is big thereby welding is sealed with strict demand, and system's aeration quantity increases, and the inner heat that dissipates is difficult to spread out of etc.

The utility model content

The purpose of this utility model is to overcome existing high frequency pulse tube cooler all need exist a big air reservoir, the size and the weight of system have been increased, and because of diameter is sealed with strict demand to welding greatly, also exist system's aeration quantity to increase in addition, the defective that the inner heat that dissipates is difficult to spread out of, thereby, provide a kind of no air reservoir type high frequency pulse tube cooler that fully phases out air reservoir by selecting elongated tubular internal diameter and length to realize phase adjusted suitably.

The purpose of this utility model realizes by the following technical solutions:

The no air reservoir type high frequency pulse tube cooler that the utility model provides, as shown in Figure 4, comprise a high-frequency pressure wave producer 1 and a pulse tube refrigerating machine 12, comprise a regenerator 4, pulse tube 6 and inertia tube 11 in the pulse tube refrigerating machine 12, the hot end heat exchanger 3 of regenerator 4 links to each other with high-frequency pressure wave producer 1 by tube connector 2, the other end links to each other with the cool end heat exchanger 5 of pulse tube 6, the hot end heat exchanger 7 of pulse tube 6 links to each other with inertia tube 11, described inertia tube 11 is an elongated tubular, the one end links to each other with the pulse tube hot end heat exchanger, other end sealing.

Described inertia tube comprises two kinds of shapes:

(1) equal diameter pipe;

(2) long tube that has the pipe of two to three kinds of different-diameters to be formed by connecting is from reducing successively near pulse tube refrigerating machine lateral seal end diameter or increasing.

The cross-sectional area of described inertia tube is littler than the cross-sectional area of pulse tube, and diameter is from 1 millimeter to 1 centimetre.

The length of described inertia tube is that 1/10 sound wave length to 1 sound wave is long, and concrete numerical value is different according to Working medium gas, operating temperature and operating frequency:

(1) helium working medium, 20 hertz, room temperature, then pipe range is between 5～51 meters;

(2) nitrogen working medium, 20 hertz, room temperature, then pipe range is between 1.7～17 meters.

Described high-frequency pressure wave producer can be valveless motor compressor and thermoacoustic compressor, described valveless motor compressor comprises that electricity drives crank-linkage type compressor, Linearkompressor, described thermoacoustic compressor comprises standing wave type thermoacoustic compressor and travelling-wave type thermoacoustic compressor, and frequency range is between 15～200 hertz.

Described pulse tube refrigerating machine comprises that straight line, U type are arranged, the single-stage pulse tube refrigerating machine of coaxial arrangement form, perhaps is the twin-stage pulse tube refrigerating machine that straight line, U type layout, coaxial arrangement or combination are arranged.

The no air reservoir type high frequency pulse tube cooler that the utility model provides is simple in structure, need not air reservoir, thereby overcome that all need there be a big air reservoir in existing high frequency pulse tube cooler and all defect that brings, it realizes the leading volume flow of pressure wave phase place in the pulse tube hot junction, thereby can improve the efficient of pulse tube refrigerating machine.

In order to be illustrated more clearly in principle of the present utility model, below in conjunction with the theoretical acoustic impedance of inertia tube provided by the invention of being analyzed of linear heat sound at openend.The inertia tube that the utility model provides is an end opening, the elongated tubular of end sealing.Linear heat sound theory is the common tool that is used for analyzing little amplitude sound field in the thermoacoustics, and formula (1) and formula (2) are its two equations that are used for describing sound field.

$\frac{d\hat{U}}{\mathrm{dx}}+R_1\hat{p}=0,{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="Y20052002297000071.png,Y20052002297000072.png"\; state="\{\{state\}\}">R</figure-callout>}}_1=\frac{\mathrm{i\&omega;A}[1+(\mathrm{\&gamma;}-1)f_k]}{\mathrm{\&gamma;}{P}_0}---\left(1\right)$

$\frac{d\hat{p}}{\mathrm{dx}}+R_2\hat{U}=0,{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="Y20052002297000072.png"\; state="\{\{state\}\}">R</figure-callout>}}_2=\frac{\mathrm{i\&omega;\&rho;}}{A(1-f_{\mathrm{\&mu;}})}---\left(2\right)$

ω wherein, A, γ, P ₀, ρ is that angular frequency, flow channel cross-section are long-pending respectively, specific heat ratio, average pressure and gas density.f _μ, f _kBe and relevant functions such as runner geometric parameter, gas rerum natura, operating frequency.

The openend surge pressure

With the fluctuation volume flow

The blind end surge pressure With the fluctuation volume flow

So (1) (2) formula is found the solution and can be obtained following relational expression:

$\left[\begin{array}{c}{\hat{p}}_b\\ {\hat{U}}_b\end{array}\right]=\left[\begin{array}{cc}{A}_{11}& A_{12}\\ A_{21}& A_{22}\end{array}\right]\left[\begin{array}{c}\widehat{p_a}\\ {\hat{U}}_a\end{array}\right]---\left(3\right)$

$A_{11}=A_{22}=\cosh \left(\sqrt{R_1{R}_2}L\right)$

$A_{12}=-\sqrt{\frac{R_2}{R_1}}\sinh \left(\sqrt{R_1{R}_2}L\right),---\left(4\right)$

$A_{21}=-\sqrt{\frac{R_1}{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="Y20052002297000072.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}}\sinh \left(\sqrt{R_1{R}_2}L\right)$

For blind end, ${\hat{U}}_b=0,$ Acoustics complex impedance Z at openend just can be expressed as so

$Z=\frac{{\hat{P}}_a}{{\hat{U}}_a}=-\frac{A_{22}}{A_{21}}=\left|Z\right|e^{\mathrm{i\&theta;}}---\left(5\right)$

When being 0 °, θ just means the phase place requirement of satisfying between high frequency pulse tube cooler paired pulses pipe hot junction pressure wave and the volume flow between 90 ° the time.Lift a typical example below.To use helium to be working medium, average pressure 2.0MPa, 80 hertz of frequencies, temperature is that the isothermal pipeline of 300K is an example, when pipe diameter is 2mm or 3mm, its phase angle θ can see in several pipe range scopes and can realize above-mentioned requirement to θ with the situation of change of duct length as shown in Figure 3.

Description of drawings

Fig. 1 is the schematic diagram of bidirection air intake type high frequency pulse tube cooler;

Fig. 2 adds the schematic diagram of air reservoir type high frequency pulse tube cooler for inertia tube;

Fig. 3 is the situation of change of the interior impedance phase angle θ of inertia tube with duct length;

The schematic diagram of the no air reservoir type high frequency pulse tube cooler that Fig. 4 provides for the utility model;

Wherein: 1 high-frequency pressure wave producer, 2 tube connectors, 3 regenerator hot end heat exchangers, 4 regenerators, 5 pulse tube cool end heat exchangers, 6 pulse tubes, 7 pulse tube hot end heat exchangers, 8 air reservoirs, 9 bidirection air intake governor motions, 10 aperture governor motions, 11 inertia tubes, 12 pulse tube refrigerating machines.

The specific embodiment

Further describe the no air reservoir type high frequency pulse tube cooler that the utility model provides below in conjunction with Fig. 4.The no air reservoir type high frequency pulse tube cooler that the utility model provides, as shown in Figure 4, comprise a high-frequency pressure wave producer 1 and a pulse tube refrigerating machine 12, comprise a regenerator 4, pulse tube 6 and inertia tube 11 in the pulse tube refrigerating machine 12, the hot end heat exchanger 3 of regenerator 4 links to each other with high-frequency pressure wave producer 1 by tube connector 2, the other end links to each other with the cool end heat exchanger 5 of pulse tube 6, the hot end heat exchanger 7 of pulse tube 6 links to each other with inertia tube 11, this inertia tube 11 is an elongated tubular, the one end links to each other with the pulse tube hot end heat exchanger, other end sealing; It can be the equal diameter pipe; Or the long tube that is formed by connecting of the pipe that two to three kinds of different-diameters are arranged, from reducing successively near pulse tube refrigerating machine lateral seal end diameter or increasing; The cross-sectional area of this inertia tube is littler than the cross-sectional area of pulse tube, and diameter is from 1 millimeter to 1 centimetre; The length of this inertia tube is that 1/10 sound wave length to 1 sound wave is long, and concrete numerical value is different according to Working medium gas, operating temperature and operating frequency.

Described high-frequency pressure wave producer can be valveless motor compressor and thermoacoustic compressor, described valveless motor compressor comprises that electricity drives crank-linkage type compressor, Linearkompressor, described thermoacoustic compressor comprises standing wave type thermoacoustic compressor and travelling-wave type thermoacoustic compressor, and frequency range is between 15～200 hertz.Described pulse tube refrigerating machine comprises that straight line, U type are arranged, the single-stage pulse tube refrigerating machine of coaxial arrangement form, perhaps is the twin-stage pulse tube refrigerating machine that straight line, U type layout, coaxial arrangement or combination are arranged

Embodiment 1

As shown in Figure 4, the no air reservoir type high frequency pulse tube cooler that the utility model provides is that a high frequency pressure waves is sent out the pulse tube refrigerating machine 12 that device 1 drives, pulse tube refrigerating machine 12 is by forming with the lower part: 2 is tube connector, 3 is the regenerator hot end heat exchanger, 4 is regenerator, and 5 is the pulse tube cool end heat exchanger, and 6 is pulse tube, 7 is the pulse tube hot end heat exchanger, and 11 is elongated tubular.

High-frequency pressure wave producer 1 can provide fluctuating range 0.166MPa when average pressure 3.0MPa, 86.8 hertz pressure wave, and its wavelength is 11.2 meters during corresponding helium working medium.The critical piece of high frequency pulse tube cooler 12 is of a size of: 15 millimeters of regenerator 4 internal diameters, 48 millimeters of length, pulse tube 6 is of a size of 6 millimeters of internal diameters, 77 millimeters of length, inertia tube 11 are an elongated tubular, and the one end links to each other with the pulse tube hot end heat exchanger, other end sealing, its internal diameter is 2 millimeters an equal diameter pipe, and 4.12 meters of length are 0.367 of sound wave length.When high-frequency pressure wave producer 1 driving pulse pipe refrigeration machine 12 was worked to stable state, pulse tube cool end heat exchanger 5 temperature arrived 97.4K.

Claims (8)

1. A high-frequency pulse tube refrigerator without an air store, including a high-frequency pressure wave generator and a pulse tube refrigerator. The pulse tube refrigerator includes a regenerator, pulse tube and inertial tube, and the regenerator The heat exchanger at the hot end is connected to the high-frequency pressure wave generator through a connecting pipe, and the other end is connected to the heat exchanger at the cold end of the pulse tube, and the heat exchanger at the hot end of the pulse tube is connected to the inertial tube. It is characterized in that: the inertial tube It is a slender tube, one end of which is connected to the heat exchanger at the hot end of the pulse tube, and the other end is closed. 2. The high-frequency pulse tube refrigerator without air storage according to claim 1, characterized in that: the inertia tube includes two shapes: (1) Equal diameter pipe; (2) A long tube formed by connecting two to three tubes with different diameters. The diameter decreases or increases sequentially from the side close to the pulse tube refrigerator to the closed end. 3. The high-frequency pulse tube refrigerator without air storage according to claim 1, characterized in that the cross-sectional area of the inertial tube is smaller than that of the pulse tube, and the diameter is from 1 mm to 1 cm. 4. The high-frequency pulse tube refrigerator without an air store according to claim 1, characterized in that: the length of the inertial tube is 1/10 to 1 sound wavelength. 5. The air-storage-type high-frequency pulse tube refrigerator according to claim 1, wherein the high-frequency pressure wave generator is a valveless electric compressor or a thermoacoustic compressor. 6. The air-storage-type high-frequency pulse tube refrigerator according to claim 5, characterized in that: the valveless electric compressor is an electrically driven crank-and-rod compressor or a linear compressor. 7. The airless storage-type high-frequency pulse tube refrigerator according to claim 5, characterized in that: the thermoacoustic compressor is a standing wave thermoacoustic compressor or a traveling wave thermoacoustic compressor, and the frequency range is Between 15 and 200 Hz. 8. The high-frequency pulse tube refrigerator without air storage according to claim 1, characterized in that: the pulse tube refrigerator includes single-stage pulse tube refrigerators in the form of linear arrangement, U-shaped arrangement, and coaxial arrangement, Or a two-stage pulse tube refrigerator with linear arrangement, U-shaped arrangement, coaxial arrangement or combined arrangement.

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