CN101280977A - Coupling device for thermoacoustic engine and refrigerator driven by thermoacoustic engine - Google Patents

Abstract

The invention relates to a coupling device for a thermoacoustic engine and a refrigerator driven by the thermoacoustic engine, comprising: a cavity; the elastic diaphragm is arranged in the cavity and divides the cavity into a first cavity and a second cavity; a long tube communicated with one side wall of the cavity and communicated with the first cavity; a short pipe communicated with the other side wall of the cavity and communicated with the second cavity; the other end of the long pipe is communicated with a feedback pipe of the thermoacoustic engine; the other end of the short pipe is communicated with a water cooler of the refrigerator; the coupling device can amplify the pressure amplitude of the pressure wave generated by the thermoacoustic engine after the pressure wave passes through the long pipe and the cavity, thereby improving the utilization rate of the system acoustic power of the refrigerating machine; the elastic diaphragm clamped in the middle of the cavity isolates working gas in the engine and the refrigerator, so that the engine can use gas such as nitrogen and the like as working medium to reduce the system frequency, and meanwhile, the refrigerator can use gas such as helium and the like as the working medium to keep good refrigerating performance.

Description

Be used for the coupling device between the refrigeration machine of thermoacoustic engine and driving thereof

Invention field

The present invention relates generally to using energy source and refrigerating field, the coupling device between particularly a kind of refrigeration machine that is used for thermoacoustic engine and driving thereof; This coupling device can improve sound merit utilization rate, the reduction operating frequency of the refrigerator system of thermoacoustic engine driving.

Background technology

Thermoacoustic engine driving pulse pipe refrigeration machine or hot sound refrigerating machine are a kind of New Refrigerating technology of complete movement-less part.It as power, by the vibration of gas, can be converted into merit with interior with heat energy in engine, produce refrigeration in refrigeration machine internal consumption sound merit, environmental protection, and safety, the life-span is long, therefore has extraordinary application prospect.

Its refrigeration warm area has covered the liquid hydrogen warm area from normal temperature at present, and will further cover the liquid helium warm area very soon, but wants to make the further raising of performance of heat sound driving pulse pipe refrigeration machine or hot sound refrigerating machine also to exist two major issues to solve.The first, vascular refrigerator and hot sound refrigerating machine usually with gases such as helium as working media, be operated in lower frequency and be advisable, when operating frequency raise, its refrigeration performance was understood variation usually.And thermoacoustic engine is when being working media with the helium, if want to make it to be operated in the following frequency of 50Hz, the length of resonatron then will reach more than the 8m, and huge like this volume is unfavorable for practical application certainly, also can consume a large amount of helium simultaneously, cost is also very high.Second, because thermoacoustic engine is bulky, if refrigeration machine and engine directly are coupled, then the pressure amplitude in the refrigeration machine can not be higher than in-engine pressure amplitude, therefore, because viscous dissipation will consume the sound merit of the overwhelming majority, have only very that a spot of merit enters in the refrigeration machine in the engine, efficient is low-down like this.

Summary of the invention

The object of the present invention is to provide the coupling device between a kind of refrigeration machine that is used for thermoacoustic engine and driving thereof, this coupling device can significantly improve the utilization rate of refrigeration machine to the sound merit, reduce system bulk simultaneously, reduce operating frequency, thereby improve the refrigeration performance of refrigeration machine.

Technical scheme of the present invention is as follows:

Coupling device between the refrigeration machine that is used for thermoacoustic engine and driving thereof provided by the invention comprises:

One cavity C;

One is installed on the flexible sheet B in the cavity C, and described flexible sheet B is divided into first cavity C 1 and second cavity C 2 with described cavity C;

One is communicated on described cavity C one sidewall and the long tube A that communicates with first cavity C 1;

One is communicated on another sidewall of described cavity C and the short tube F that communicates with second cavity C 2;

The other end of described long tube A is communicated in the feedback pipe 12 of thermoacoustic engine;

The other end of described short tube F is communicated in the water cooler 21 of refrigeration machine.

Described first cavity C 1 and second cavity C 2 are for being equipped with the chamber of different operating medium.

Described long tube A length is less than 1/4 of sound wave length, and described long tube 1 diameter is less than thermoacoustic engine feedback pipe 12 diameters.

The area that described flexible sheet B is vertical with the working media flow direction is 5-200 a times of described long tube A cross-sectional area.

Described flexible sheet B is organic material flexible sheet or metal material flexible sheet, and its quality is light and handy, and recovery capacity is strong, and gas permeability is low.

Described thermoacoustic engine comprises travelling-wave type thermoacoustic engine, standing wave type thermoacoustic engine and tandem type thermoacoustic engine.Described refrigeration machine comprises pulse tube refrigerating machine and hot sound refrigerating machine.

The working gas that uses in the described engine is mainly the gas such as nitrogen, carbon dioxide, argon gas or the mixture of several gases wherein; The working gas that refrigeration machine uses is mainly the gas such as helium, hydrogen, neon, nitrogen or the mixture of several gases wherein.

In order to further specify the operation principle of the coupling device between the refrigeration machine that is used for thermoacoustic engine and driving thereof of the present invention, also further specify simultaneously required some principles of following when selecting then long tube, cavity, will make an explanation to its principle theoretically below.

We analyze the characteristic of coupling device of the present invention with linear heat sound theory.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.

$\frac{d\hat{U}}{\mathrm{dx}}+R_1\hat{p}=0,{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="A20071006510600121.png"\; state="\{\{state\}\}">R</figure-callout>}}_1=\frac{\mathrm{i\&omega;A}[1+(\mathrm{\&gamma;}-1)f_k]}{\mathrm{\&gamma;}{P}_0}---\left(1\right)$

$\frac{d\hat{p}}{\mathrm{dx}}=R_2\hat{U}=0,{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="A20071006510600121.png,A20071006510600122.png"\; state="\{\{state\}\}">R</figure-callout>}}_2=\frac{\mathrm{i\&omega;\&rho;}}{A(1-f_{\mathrm{\&mu;}})}---\left(2\right)$

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.

Suppose this coupling device be connected with engine the end surge pressure and volume flow be p _aAnd U _a, the surge pressure and the volume flow at a place of the end that is connected with refrigeration machine are p _bAnd U _b, can obtain following relational expression by (1) (2) formula so:

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

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

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

$A_{21}=-\sqrt{\frac{R_1}{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="A20071006510600121.png,A20071006510600122.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}}\sinh \left(\sqrt{R_1{R}_2}L\right)$

Definition magnifying power γ:

$\mathrm{\&gamma;}=\frac{\left|p_b\right|}{\left|p_a\right|}=\frac{|A_{11}+P_a+A_{12}{U}_a|}{\left|p_a\right|}=|A_{11}+A_{12}\frac{{\mathrm{ZA}}_{21}-A_{11}}{A_{12}-A_{11}}|$

Wherein: Z=p _b/ U _bImpedance for refrigeration machine

The relation curve of magnifying power and long tube length when Figure 2 shows that different cavity volume.The relation curve of magnifying power and long tube length when Figure 3 shows that different long tube diameter.The parameter of using in the calculating is: long tube diameter 8mm, and average pressure 2.1MPa, working gas are helium, operating frequency 67.5Hz, the refrigeration machine impedance is (9.3-5.9i) * 10^8Pa-s/m ³The working gas that elastic membrane is used by the long tube side is nitrogen, and the working gas that opposite side uses is helium.

From this two figure as can be seen: for certain long tube diameter and cavity volume, all exist the long tube length an of the best to make multiplication factor reach the highest, this optimum length is less than 1/4 of sound wave length; The big more multiplication factor that can obtain of long tube diameter is big more, and the big more multiplication factor that can obtain of cavity volume is also big more.

Worth illustrate be, show that cavity volume is big more though calculate, magnifying power is big more, owing to there are abrupt-change cross section in long tube and cavity cross section, if cavity is excessive, flow losses will become greatly, and magnifying power may can diminish on the contrary, therefore, in real process, cavity volume is unsuitable excessive.

The sound merit that refrigeration machine consumed can be calculated according to such formula:

$W=\frac{{\left|p_b\right|}^2}{Z}$

When the acoustic pressure amplitude that thermoacoustic engine provided | P _a| one regularly, if engine and refrigeration machine directly are coupled, and p so _b=p _a, then

$W=\frac{{\left|p_a\right|}^2}{Z}$

If but the coupling device that uses the present invention to propose is coupled p _b=γ p _a, then

$W={\mathrm{\&gamma;}}^2\frac{{\left|p_a\right|}^2}{Z}$

That is to say and use coupling device of the present invention, the sound merit that refrigeration machine utilized has just become original γ ²Times, so the sound material gain of system has obtained the raising of several times with efficient.

At present hot sound refrigerating machine and pulse tube refrigerating machine all are to use helium as working media basically, and obtaining better service behaviour, when using other gases such as nitrogen as working medium, cryogenic temperature and refrigeration performance are all understood variation usually.Another characteristics of these refrigeration machines are exactly that its refrigeration performance usually can be better when being operated in lower frequency, therefore, will reduce frequency when the driver of these refrigeration machines of design as far as possible.

We know that the velocity of sound of helium is three times of nitrogen, if engine will obtain same operating frequency, then with helium during as working medium the length of resonatron be during with nitrogen three times, that is to say, if use identical resonatron, with nitrogen during as working medium, operating frequency only for helium the time 1/3.So in order to obtain lower operating frequency, can keep the superperformance of refrigeration machine simultaneously again, the present invention installs a flexible sheet between refrigeration machine and engine, making engine can be working medium with gases such as nitrogen, and refrigeration can be a working medium with gases such as helium.This flexible sheet is should quality light and handy, and recovery capacity is stronger, and gas permeability is low, with smooth transmission that guarantees sound wave and the mixing that prevents gas.

Compared with prior art, the coupling device between the refrigeration machine that is used for thermoacoustic engine and driving thereof provided by the invention, can make engine can be working medium with gases such as nitrogen, refrigeration can be a working medium with gases such as helium.This flexible sheet is should quality light and handy, and recovery capacity is stronger, and gas permeability is low, can guarantee the smooth transmission of sound wave and prevent the mixing of gas; And this coupling device can make the system bulk minimizing, operating frequency reduction, the raising of sound merit utilization rate.

Description of drawings

Fig. 1 is the structural representation of coupling device of the present invention;

The relation curve of magnifying power and long tube length when Fig. 2 is different cavity volume;

The relation curve of magnifying power and long tube length when Fig. 3 is different long tube diameter;

Fig. 4 is the structural representation of specific embodiment cavity;

Fig. 5 drives the single-stage pulse tube refrigerator schematic diagram for traveling wave thermoacoustic engine;

Fig. 6 drives twin-stage vascular refrigerator schematic diagram for traveling wave thermoacoustic engine;

Fig. 7 is a standing wave motor driven row ripple hot sound refrigerating machine schematic diagram.

The specific embodiment

Below in conjunction with Fig. 5～Fig. 7 coupling device between a kind of refrigeration machine that is used for thermoacoustic engine and driving thereof of the present invention is described.

Embodiment 1: adopt coupling device shown in Figure 5; Described coupling device comprises: a cavity C;

One is installed on the flexible sheet B in the cavity C, and described flexible sheet B is divided into first cavity C 1 and second cavity C 2 with described cavity C;

One is communicated on described cavity C one sidewall and the long tube A that communicates with first cavity C 1;

One is communicated on another sidewall of described cavity C and the short tube F that communicates with second cavity C 2;

The other end of described long tube A is communicated in the feedback pipe 12 of thermoacoustic engine by ball valve 1;

The other end of described short tube F is communicated in the water cooler 21 of refrigeration machine.

Engine is traveling wave thermoacoustic engine (indicating with D), this traveling wave thermoacoustic engine is made up of engine first water cooler 2, engine regenerator 3, engine heater 4, engine thermal separator tube 5, engine second water cooler 22 and feedback pipe 12 and resonatron 13, and formation annular ring, the diameter of each parts of formed annular ring is 80mm, each part length summation of forming annular ring is about 2m, resonatron 13 is by a segment length 5m, and diameter changes to the conical pipe of 300mm and the straight tube composition of the long 1m of an end diameter 300mm from 80mm; It is working medium that this traveling wave thermoacoustic engine adopts nitrogen, and operating frequency is 23.5Hz; Refrigeration machine E is the single-stage pulse tube refrigerating machine of U type design, adopts helium as working medium; Its refrigeration machine regenerator 31 long 80mm, diameter 20mm, refrigeration machine vascular 10 long 160mm, diameter 10mm.

The long tube A length of the coupling device between the refrigeration machine E that is used for thermoacoustic engine D and driving thereof of present embodiment is 0.8m, and diameter is that (cross-sectional area is about 0.5cm to 8mm ²), be connected by the feedback pipe 12 of ball valve 1 and traveling wave thermoacoustic engine D; The flexible sheet B of coupling device is the thick fluorubber film of 1mm; The cavity C of coupling device is an elliposoidal, concrete structure as shown in Figure 4, cavity C is made up of the approximate semielliptical parts of two processing on flange, total measurement (volume) is about 75cc; Clamp the flexible sheet B of trapping between two flanges, the area that flexible sheet B is vertical with the working media flow direction is 100cm ²(be about long tube A cross section about 200 times); The cavity C total height is 36mm.Gas in the cavity C communicates with long tube and short tube respectively by the aperture of many processing on flange; Adopt such structure can make the maximum monolateral displacement of flexible sheet B be no more than 18mm, can prevent that like this diaphragm deformation amount is excessive to be damaged owing to refrigeration machine internal pressure imbalance causes.When this refrigeration system was 2000W at heating power, cryogenic temperature can reach 34.1K.

Embodiment 2: adopt constructional device shown in Figure 6.The size of engine D is identical with size of engine among the embodiment 1; Long tube A length is 1.6m in the coupling device, and diameter is 17mm, and the annular ring that forms at each parts of engine is communicated with resonatron 13 joints and engine; The structure of cavity C and size are identical with cavity among the embodiment 1, and the elastic membrane B area vertical with the working media flow direction in the cavity C is about about 50 times of long tube A cross section; Refrigeration machine is the two-stage pulse tube refrigerating machine of U type design; Refrigeration machine one-level regenerator 31 long 80mm, diameter 30mm, refrigeration machine secondary regenerator 32 long 80mm, diameter 12mm, refrigeration machine one-level vascular 10 long 104mm, diameter 12mm, refrigeration machine secondary vascular 101 long 160mm, diameter 8mm; It is working medium that engine adopts nitrogen, operating frequency 23.5Hz, and it is working medium that refrigeration machine adopts helium, lowest refrigerating temperature can reach 18.3K.

Embodiment 3: adopt constructional device shown in Figure 7.Engine is the standing wave hot sound refrigerating machine, and hot chamber, heater, regenerator and water cooler total length are 238mm, and diameter is 100mm.Resonatron is by a segment length 3m, and diameter changes to the conical pipe of 200mm and the straight tube composition of the long 0.5m of an end diameter 200mm from 100mm.Long tube A length is 1m in the coupling device, and diameter is 50mm, is connected by ball valve and engine.Flexible sheet is the thick nitrile rubber film of 1mm.

The diameter of elastic membrane B in the cavity C is 120mm, and its area vertical with the working media flow direction is about about 5 times of long tube A, and the cavity C total height is 100mm.Refrigeration machine is a hot sound refrigerating machine, and the annular ring overall circumference is 1.2m, the feedback pipe, and regenerator, parts diameters such as separator tube are 30mm, capacitive pipe is the spherical hollow space of diameter 60mm.It is that 80% nitrogen and percent by volume are that 20% carbon dioxide is a working medium that engine adopts percent by volume, and it is that 90% helium and percent by volume are that 10% hydrogen is working medium that refrigeration machine adopts percent by volume.This refrigeration system is estimated and can be obtained refrigeration preferably at the room temperature warm area.

Claims (5)

1. the coupling device between the refrigeration machine that is used for thermoacoustic engine and driving thereof is characterized in that, comprising:

One cavity (C);

One is installed on the flexible sheet (B) in the cavity (C), and described flexible sheet (B) is divided into first chamber (C1) and second chamber (C2) with described cavity (C);

One is communicated on described cavity (C) sidewall and the long tube (A) that communicates with first chamber (C1);

One is communicated on another sidewall of described cavity (C) and the short tube (F) that communicates with second chamber (C2);

The other end of described long tube (A) is communicated in the feedback pipe (12) of thermoacoustic engine;

The other end of described short tube (F) is communicated in the water cooler (21) of refrigeration machine.

2. by the coupling device between the described refrigeration machine that is used for thermoacoustic engine and driving thereof of claims 1, it is characterized in that described first chamber (C1) and second chamber (C2) are for being equipped with the chamber of different operating medium.

3. by the coupling device between the described refrigeration machine that is used for thermoacoustic engine and driving thereof of claims 1, it is characterized in that, described long tube (A) length less than sound wave long 1/4, described long tube (A) diameter is less than thermoacoustic engine feedback pipe (12) diameter.

4. by the coupling device between the described refrigeration machine that is used for thermoacoustic engine and driving thereof of claims 1, it is characterized in that, the area that described flexible sheet (B) is vertical with the working media flow direction be described long tube (A) cross-sectional area 5-200 doubly.

5. by the coupling device between the described refrigeration machine that is used for thermoacoustic engine and driving thereof of claims 1, it is characterized in that described flexible sheet (B) is organic material flexible sheet or metal material flexible sheet.

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