EP1043491A1 - Process and device for generating and transferring mechanical energy from a Stirling engine to an energy consuming element - Google Patents

Abstract

The method of power transmission from a Stirling engine has a drive piston (6) in a cylinder. The piston rod (6A) has a sect (AP) with a ratio to that of the piston which produces a total transmission to an output (11). A pneumatic resonator (18) is connected to the hot (Ve) and cold (Vc) chambers and adjusted so that the pressure wave is de-phased with respect to the transfe piston.

Description

The present invention relates to a method for generate and transmit mechanical energy from a piston transfer of a Stirling engine to a consumer body energy, the transfer piston being mounted in a cylinder, that gas is periodically moved between a hot room and a cold room at the ends respective of this cylinder by passing it through a hot exchanger connected to a hot source, a regenerator and a cold exchanger connected to a cold source and we exercise an elastic restoring force on this transfer piston. This invention also relates to a device for the implementation of this process.

Stirling free piston engines were considered for a long time as an ideal solution for units of heat-force coupling used for energy production thermal and mechanical for dwellings. The possibility increase the degree of use of fossil fuel, cleanliness, silent external combustion process are the main arguments in favor of the application from this technology to homes. However so far, the complexity and high price of such units have prevented his employment.

It has recently been proposed to associate a driving piston with a transfer piston from a Stirling engine and attach the magnets inductors of an electric alternator to this driving piston to move them relative to the armature windings of this alternator. This promising concept, however, presents the disadvantage of requiring two coaxial pistons, movable relative to each other, which must be guided with great precision. Indeed, the piston rod of transfer is mounted sliding in a closed closed volume gas from the engine piston, which acts as a return means elastic. This system also requires a servo so as to adjust the phase difference between these pistons. Such a system is developed by the American firm Sun-power Inc. Athens, Ohio, and was notably the subject of a article titled "Development of a 3kW free-piston Stirling engine with the displacer gas-spring partially sprung to the power piston ”G. Chen and J. McEntee, Proceedings of the 26th Intersociety Energy Conversion Engineering Conference, flight. 5, p. 233-238. Strong elastic coupling between two pistons indicates that a substantial fraction of the induced motor energy is generated by the forces of the gas acting on the transfer piston and transferred by elastic coupling to the engine piston. The authors of the article claim that 2/3 of the total energy is produced by the transfer piston of the Stirling engine. In this engine, this piston therefore not only serves to transfer the gas between hot and cold volumes located at both ends of the cylinder in which this piston moves, but also to generate part of the driving energy.

One could certainly legitimately wonder, therefore, if it would not be possible to produce all of motive energy using the transfer piston and to associate the mobile part of the electric generator with this one. Such an assumption alone would not resolve however, not the above problems. Indeed, the phase difference required between the two coaxial pistons in front subsist to allow energy production and its transfer, guidance and enslavement problems would remain unchanged.

The object of the present invention is to remedy the less in part to the aforementioned drawbacks.

To this end, this invention firstly relates to a process for producing and transmitting mechanical energy a transfer piston from a Stirling engine to an organ energy consumer as defined in claim 1. The subject of this invention is also a device for the implementation of this method, according to claim 9.

Replacement of the engine piston by a resonator fully static pneumatic not only allows greatly simplify the device, as is obvious, since this process removes the piston engine, but also to facilitate the enslavement as we will explain it later. This means that not only the invention makes it possible to significantly simplify the device and reduce production costs, but also that reliability of the device is thereby increased. So that a such a device is of economic interest; only that it can be produced at a competitive price, but that it is able to function also many years without requiring any maintenance or adjustment.

La figure 1 est une vue en coupe diamétrale de cette forme d'exécution;

la figure 2 est une vue semblable à la figure 1 d'une variante;

la figure 3 est une vue en élévation du dispositif selon les figures 1 ou 2;

la figure 4 est un diagramme vectoriel, les figures 5 et 6 sont des diagrammes explicatifs relatifs au procédé;

la figure 7 est un diagramme relatif au rendement du cycle par rapport au travail par cycle;

les figures 8 à 10 sont des diagrammes relatifs au dimensionnement et au comportement du résonateur;

la figure 11 est une vue en élévation, partiellement en coupe de la seconde forme d'exécution;

les figures 12 et 13 illustrent partiellement deux variantes pour le chauffage du moteur Stirling;

les figures 14 à 16 illustrent trois variantes dans lesquels des moteurs Stirling sont accouplés par des tubes de résonance;

la figure 17 illustre un mode de chauffage applicable aux variantes des figures 14 à 16.

Other features and advantages of the method and the device which are the subject of the invention will become apparent on reading the description which follows, as well as the appended drawing, which illustrates, schematically and by way of example, two and various embodiments variants of this device.

Figure 1 is a diametrical sectional view of this embodiment;

Figure 2 is a view similar to Figure 1 of a variant;

Figure 3 is an elevational view of the device according to Figures 1 or 2;

FIG. 4 is a vector diagram, FIGS. 5 and 6 are explanatory diagrams relating to the method;

FIG. 7 is a diagram relating to the performance of the cycle in relation to the work per cycle;

Figures 8 to 10 are diagrams relating to the dimensioning and the behavior of the resonator;

Figure 11 is an elevational view, partially in section of the second embodiment;

Figures 12 and 13 partially illustrate two variants for heating the Stirling engine;

Figures 14 to 16 illustrate three variants in which Stirling engines are coupled by resonance tubes;

FIG. 17 illustrates a heating mode applicable to the variants of FIGS. 14 to 16.

The device illustrated in FIG. 1 comprises an elongated casing 1 formed by two cylindrical compartments 2, 3, assembled on an intermediate element 4, playing the role of frame. The cylindrical compartment 2 comprises a cylindrical housing 5, constituting a working volume, in which a transfer piston 6 is mounted free to move in the longitudinal axis of the cylindrical housing 5. At one end, the volume located between the piston 6 and the outer end of the housing 5 is that which is in contact with a hot exchanger 7 connected to a hot source (not shown) and constitutes the hot chamber or expansion volume V _E of the Stirling engine, while at the at the other end of this cylindrical housing 5, there is a volume in contact with a cold exchanger 8 connected to a cold source (not shown), which constitutes the cold room or compression volume V _C of the Stirling engine. A regenerator 9 is placed between the hot 7 and cold 8 exchangers.

The end of the piston 6 adjacent to the cold room V _C comprises a piston rod 6a, engaged in a closed volume 10 filled with gas and which constitutes an elastic return member of the transfer piston 6.

The cylindrical compartment 3 contains a volume in which a moving element of an alternator, in this example, inductor 11 consisting of a cylindrical element carrying permanent magnets, is attached to the periphery of a annular member 12, the internal edge of which is integral with a elastic suspension member 14, constituted by springs annular plates, the peripheral edges of which are fixed to the frame 4 and whose internal edges are integral a rod 17, one end of which is fixed to the rod 6a of the piston 6. The internal edge of a second suspension member elastic 15 similar to member 14, is attached to the other end of rod 17, while its periphery is fixed to a support 13 secured to the frame 4. The armature of the alternator is formed by windings 16.

Rods 6a and 17 cross the bottom of the closed volume 10 formed in the intermediate element 4 with a clearance included between 30 and 50µm. Such a game is perfectly acceptable both in terms of manufacturing tolerances and the influence of gas leaks on energy efficiency and on the restoring force of the compressed gas in the volume closed 10.

A tubular resonator 18, of which only the integral end of the cylindrical compartment 2 is shown in FIG. 1, communicates with the compression volume or cold room V _C of the Stirling engine. This resonator has the role of replacing the second piston, which according to the process which is the subject of the invention, no longer serves to produce energy, all the energy being produced by the transfer piston 6, as will be explained below. -afterwards, but serves to amplify the pressure wave and to ensure an appropriate phase shift between the displacement of the transfer piston 6 and the pressure variations p in the working volume.

As illustrated in Figure 3, the other end of this tubular resonator 18 advantageously ends in a volume of Helmholtz 19. In this case, preferably, the part of this resonator which is in the Helmholtz volume ends with a flare 18a.

The transfer piston 6 then plays the double role of transferring the gas between the hot room V _E and the cold room V _C and of producing all the driving energy transmitted to the inductor 11, provided that certain conditions, including let's go talk now, be met.

To achieve this objective, it is necessary to determine the ratio between the area a _p of the rod 6a of the piston 6 and that a of the piston itself.

Analysis of the isothermal cycle shows that the pressure of the gas in the working volume becomes independent of the position of the piston 6 if: at P at = T H - T VS T H

Example

Temperature T _H of the hot space V _E , T _H = 923 ° K = 650 ° C

Temperature T _C of the cold volume V _C , T _C = 323 ° K = 50 ° C at P / a ≤ 0.65

Engine operation is possible only if the surface ratio a _P / a is less than this limit, that is to say that the displacement of the piston 6 must induce a pressure component p _X (fig. 4) which must be opposed to the displacement X of the piston 6. The displacement of the transfer piston 6 is positive if the latter moves in the direction of the volume V _E. The variation in the quantity of gas WG in the working volume of the Stirling gives rise to a variation in pressure p _W , which is in phase with WG. The variation of the pressure p in the working volume of the Stirling corresponds to the vector sum of the two partial pressures p _X and p _W.

Figure 5 shows the variation of the X position of the piston 6 and the variation of pressure as a function of time (or angle Φ). This representation corresponds schematically to that of figure 4. When the pressure decreases, gas is largely in the chamber hot or relaxing; when it increases, the gas is found mainly in the cold or compression room. To produce energy, the displacement X of the piston 6 precedes the pressure variation p.

Figure 6 shows the variation in the amount of WG gas in Stirling working volume and pressure p in this volume. When the gas flows to the resonator tubular 18 (WG decreases), the pressure is greater than during its return (WG increases). So there is a transport of energy from the Stirling volume to the tube, which compensates for friction losses in this tubular resonator 18.

In order for p to lag behind WG, FIG. 4 shows that p _X must be opposite to X. If p _X becomes zero, or oriented in the direction of X, no energy is transmitted to the tubular resonator 18 to compensate for the losses by friction. Therefore, the pressure wave cannot be maintained and the machine stops working.

Following an optimization study carried out using a computer program specially adapted for the calculation of Stirling cycles according to the present invention, the results have shown that the ratio of the sections a _P / a must be between 0.4 and 0.6, preferably between 0.45 and 0.55.

FIG. 7 gives an example of the efficiency of the cycle η _C calculated as a function of the work provided by cycle E, with the wall temperature T _H of the hot chamber V _E and the amplitude X of the piston 6 as a parameter. The temperature of the cold exchanger T is equal to 50 ° C. The net efficiency of the engine can be obtained by multiplying the efficiency of the cycle by the efficiency of the heating means and that of the alternator.

This diagram shows that in a relatively large amplitudes of the piston, we can get good yields, the highest values being reached at partial load. These yields are slightly lower to those of the above-mentioned prior art device, but this very slight decrease is more than offset by the simplification brought to the device.

The engine should always operate at hot chamber temperatures between 600 ° and 700 ° C. In this range, the temperature T _H of the hot chamber V _E mainly influences the power, to a lesser extent the efficiency. But by lowering the temperature to 400-500 ° C, the efficiency and power decrease sharply, mainly because, under these conditions, the pressure variation p _X induced by the movement of the piston becomes small and finally disappears completely.

The lateral rigidity of the mechanical suspension of the piston 6 is ensured by flat springs 14, 15 of the type described in “Recent developments in cryocoolers” Ray Radebaugh 19 ^TH International Congress of Réfrigeration 1995 Proceedings Volume IIIb, allows it to oscillate perfectly along the longitudinal axis of the cylindrical housing 5, so that the pneumatic bearings to center it are not necessary. During the initial assembly, the piston 6 can be centered with great precision. Due to the pneumatic suspension of this piston 6 and therefore the low forces required for the elastic suspension elements constituted by the annular flat springs 14 and 15, the amplitude of the piston 6 can be increased from 25% to 50% by relation to the device described in “Free-piston Stirling design features” Neill W. Lane et al. 8 ^TH International Stirling Engine Conference and Exhibition May 27-30, 1997 Ancona. This increase in amplitude leading to an increase in linear speeds, makes it possible to reduce the dimensions of the alternator. Under unchanged operating conditions, similar amounts of energy can be reached.

Using a single movable piston simplifies starting and power control significantly compared to conventional Stirling piston systems free. The rigidity of the suspension of the piston 6 and by Therefore, the phase angle can be adjusted by adjusting gas pressure in the working volume of the Stirling. The natural frequency of tubular resonator 18 can be adjusted by varying the composition of the gas, i.e. its molecular weight.

The engine is then started by first bringing the temperature of the gas in the hot chamber V _E to a value T _H at which the pressure of the working gas becomes independent of the position of the piston. The engine load is thus reduced to a minimum (losses by internal friction of the engine and by periodic flow through the exchangers and the regenerator). After starting, the temperature T _H will be adjusted to the optimum working temperature.

Power control is very easy. The amplitude of the piston 6 and therefore the power of the engine is adjusted, by adjusting the braking force exerted by the alternator to a determined value. For given gas temperatures T _H , T _C in the hot and cold chambers respectively, the output power varies in proportion to the amplitude of the piston 6. The heating power of the burner (not shown) intended to heat the gas in the chamber hot V _E is continuously adjusted to maintain the desired temperature T _H in this hot or expansion chamber V _E. Under normal conditions, the amplitude of the piston can therefore be precisely controlled. It is therefore not necessary to provide additional dead volume to avoid shocks in the event of accidental overshoot of the piston. It is only necessary to prevent the piston from exceeding a maximum amplitude in the event of a breakdown in the electrical network with which the alternator is associated.

Any non-linearity in the rigidity of the suspension of the free piston 6 has a marginal effect on its phase given that it is coupled to a load and behaves like an oscillator heavily amortized.

Once the entire device is sealed, the natural frequency of the tubular resonator 18 only depends on the average temperature of the working gas therein. This temperature can be precisely adjusted to the desired value by means of an additional heat exchanger 20 arranged in the Helmholtz volume 19 and by controlling the thermal energy extracted. This allows the phase angle of the resonator to be adjusted relative to the other variables of the system. The heat extraction from the tubular resonator 18 makes it possible to reduce the cooling of the gas located in the cold room V _C , which makes it possible to simplify the cold exchanger of the Stirling engine. Its dead volume and / or its losses by pneumatic friction can be reduced, bringing an additional advantage to the device which is the subject of the present invention.

The working gas pressure in the Stirling volume varies cyclically depending on the oscillation of the pressure wave in the tubular resonator 18. In varying the cross-section of the tube as appropriate we will explain it below, we can get variations of almost perfectly sinusoidal pressure. Dissipation energy is then exclusively due to friction losses fluid and remain moderate, at least for variations pressure considered in this application. The parameters of the tubular resonator 18, an example of which follows, must be adjusted to those of the Stirling process to ensure that these components interact properly, that is to say that the wave is driven by the cycle Stirling and that the resulting pressure variations maintain the periodicity of the Stirling cycle.

By way of example, the tubular resonator 18 can have a total length including the Helmholtz volume 19, of approximately 1.6 m, and a temperature T of 40 ° C. The average pressure p ₀ of the gas is 4 MPa and the resonant frequency of this resonator is 50 Hz. To limit the length of the tube, a gas heavier than helium is advantageously used, such as a mixture of helium and argon or carbon dioxide with a molecular mass M of the gas of 14 kg / kmol. The minimum section S _min of the tubular resonator 18 is, in this example, 4.75 cm ² . The volume of gas V _S of the Stirling 2 engine is 1000 cm ³ , while that of the volume of Helmholtz 19 is 6000 cm ³ .

Advantageously, the tubular resonator can be extended inside the Helmholtz volume 19. Given that this portion of the tube is only exposed to limited pressure differences, wall may be thin and can thus easily be put in conical form 18a preventing the formation of steep front pressure waves.

An example of sectional distribution along the tube 18 of the resonator is represented on the diagram of the figure 8. The left end of the diagram corresponds to the end of tube 18 in communication with the Stirling compartment 2, while the right end corresponds to that which communicates with the volume Helmholtz 19.

The diagram in Figure 9 shows nine values to regular intervals of the gas flow velocity in the tube 18, related to the speed of sound (therefore to the number of Mach) depending on the position in the tube 18 during a cycle, while the diagram in Figure 10 shows the distribution of gas pressure relative to pressure average during the same cycle.

The pressure diagram clearly shows that with a appropriate sizing of the tube, no shock occurs at the resonance conditions of the tube 18. The pressure in the Stirling 2 volume varies sinusoidally. The pressure and speed are orthogonal functions, that is to say that if the pressure takes an extreme value, the gas speed is null and vice versa.

The calculated quality factor for tube 18 is between 25 and 40 for a pressure ratio in the Stirling volume π _C = p _max / p _min = 1.1, respectively between 15 and 25 for π _C = 1.2. The range indicated takes account of the fact that, on the one hand, the coefficient of friction of the gas in unsteady state can differ from that of an established regime, on the other hand that the roughness of the tubes is known only approximately.

In the case of the low power Stirling engine studied in this example, typically of the order of 2 kW to 5 kW, the volumes of gas displaced are of the order of a hundred cm ³ . The cylindrical parts of the tube typically have diameters of 2.5 to 4cm. It can easily be curved or rolled up so that the entire device occupies as small a volume as possible. By way of example, the device illustrated in FIG. 3 can have a height of 90cm, a width of 60cm and a depth of 40cm.

The variant illustrated in Figure 2 does not differ from the embodiment of Figure 1 only by the fact that the body elastic return of the transfer piston 6, is no longer constituted by the closed volume 10, but directly by the cylindrical compartment 3 containing the alternator. In indeed, this compartment is also a closed volume and can so also serve as an elastic reminder and replace thus the volume 10 of the embodiment of Figure 1.

So far we have only described one form of execution in which the mechanical energy produced is transmitted to a reciprocating member like that of the free piston of the Stirling engine. Alternatively, it would also be possible to transform this alternative movement into a movement rotary as is well known in the case of motors with explosion or steam engines.

Such a variant is illustrated by FIG. 11 in which we find the end of the free piston 6a 'and that of the resonance tube 18' communicating with the cold room or compression volume V _C. A rod 21 is slidably mounted in a cylindrical guide 22 by linear bearings 31. A connecting rod 23 is articulated by one end to the rod 21 and by its other end, to a crankshaft 24 integral with the axis of a rotary electric generator for example, mounted in an enclosure 25.

In a variant not shown in Figures 1 to 3 in particular, the tubular resonator 18 can be constituted by two identical tubular elements arranged in opposition diametral with respect to said transfer piston 6, of so as to balance the lateral forces exerted on this piston 6.

As a variant, the tubular resonator 18 can be connected to the expansion volume V _E or hot compartment of the Stirling engine, provided that the whole of this tube is kept warm and does not constitute a heat sink. FIG. 12 illustrates a variant in which the Helmhotz volume 19 is placed in a heating enclosure 26, heated by gaseous, liquid or solid fuels, while the tube 18 is surrounded by thermal insulation 27. It is thus possible to increase the temperature of the working gas contained in the tubular resonator 18 above the temperature T _H of this gas in the expansion volume V _E. The tubular resonator 18, 19 can then partially or entirely replace the hot exchanger 7 of the Stirling engine. This therefore results in the partial or total saving of a complicated exchanger, costly and difficult to optimize (sufficient exchange surface with a reduced dead volume and low pressure losses). The tubular resonator 18, 19 has a considerable exchange surface and thanks to the periodic flow which is established therein, the internal heat transfer is favorable. Due to the standing wave regime which is established in this resonator, its internal volume is not part of the dead volume of the Stirling engine.

The operating principle of the Stirling cycle remains the same as that explained using figures 4 to 6.

To promote heat exchange we can increase the exchange surface using fins 30 inside and / or outside the Helmholtz volume 19. Since the diameter of the tube 18 is already of the order of 2 to 4 times greater to that of heat exchanger 7 and that the diameter Helmholtz volume is still 2 to 4 times higher to that of tube 18, the spacing between the fins can be significantly increased. Therefore, such exchanger is much less sensitive to fouling by soot or other combustion residues than exchangers Small conventional stirling. If necessary, it can easily be cleaned and is therefore particularly well suited for fuel systems solids or biomass.

The variant illustrated in FIG. 13 shows a configuration in which the tubular resonator 18 is integrated in a high temperature solar collector. To this end, the tube 18 of the resonator is put in the form of a helix, placed inside a cylindrical or conical cavity 28. One end of this tubular resonator 18 opens in a volume of Helmholtz 19, while that the other end communicates with the expansion volume V _E of the Stirling engine, of which the transfer piston 6 and the regenerator 9 have been shown. A parabolic mirror 29 placed under the opening of the cavity 28, concentrates the solar radiation inside of it.

One of the advantages of this solution lies in the fact that such a collector is relatively insensitive to the exact distribution of the incident solar radiation, since the periodic movement of the gas in the tube 18 of the resonator ensures a uniform distribution of the temperature in this one. Another advantage results from the fact that when the sun appears, at the moment when a temperature level T _H of the gas in the hot chamber V _E is reached, the Stirling engine is easily started; the risk of instant collector overheating is thus reduced.

Another variant (FIG. 14) very schematically illustrates the combination of four Stirling engines of which it has been shown that the respective compression volumes V _CA , V _CB , V _CC , V _CD , alternatively the respective expansion volumes V _EA , V _EB , V _EC , V _ED , connected by four tubular resonators T ₁ , T ₂ , T ₃ and T ₄ . The whole forms a closed loop, each volume V being connected to two other neighboring volumes, the whole forming a square of which the resonance tubes T ₁ to T ₄ constitute the sides, the volumes V _CA to V _CD , alternately V _EA to V _ED being arranged at the corners. This configuration makes it possible to increase the thermal power by associating machines with each other according to a modular design.

When two motors are coupled via a tubular resonator in a symmetrical configuration, they work in phase opposition. When we have four motors arranged at the vertices of a square as in the figure 14, the motors which are on the same diagonal are in phase and are 180 ° out of phase with respect to the two other motors arranged on the other diagonal. Forces transmitted to the outside by this set are fully compensated, which reduces transmitted vibrations outside.

The section variations given to the tubes T ₁ to T ₄ also make it possible to balance the dynamic forces of the movement of the working gas in these tubes.

The variant of FIG. 15 simply shows two pairs of motors whose compression volumes V _CA , V _CB , respectively V _CC , V _CD , alternatively the expansion volumes V _EA , V _EB , respectively V _EC , V _ED , are connected by two tubular resonators T ₁ , respectively T ₂ , while the compression volumes V _CA and V _CC on the one hand, and the compression volumes V _CB and V _CD , on the other hand, alternately the expansion volumes V _EA and V _EC on the one hand and the expansion volumes V _EB and V _ED , on the other hand, are connected to each other by connecting tubes T _C1 and T _C2 whose role is to ensure that the pressures of the compression volumes, alternately of expansion, thus connected are the same since the motors arranged diagonally are in phase.

FIG. 16 shows two Stirling engines illustrated by their only compression volumes V _CI , V _CII , alternatively their expansion volumes V _EI , V _EII connected by a tubular resonator 18.

FIG. 17 shows the heating of a tubular resonator 18 connecting two Stirling engines as illustrated by FIGS. 14 to 16, arranged in a heating enclosure 26. The respective ends of the tube 18 of this resonator communicate with the expansion volumes V _EI , V _EII of two Stirling engines. Thus the tube 18 of the resonator common to these two motors also constitutes a heating element common to these two motors. It would also be possible to use several resonance tubes 18 in parallel in order to increase the exchange surface and improve the heat transfer.

Claims (17)

Method for generating and transmitting mechanical energy from a transfer piston (6) of a Stirling engine to an energy-consuming member (11), the transfer piston (6) being mounted in a cylinder (2) , according to which gas is periodically moved between a hot chamber (V _E ) and a cold chamber (V _C ) formed at the respective ends of this cylinder (2) by passing it through a hot exchanger (7) connected to a source hot, a regenerator (9) and a cold exchanger (8) connected to a cold source and an elastic restoring force is exerted on this transfer piston (6) by means of a rod (6a) integral with this piston (6), characterized in that a section is created between the section (a _P ) of said rod (6a) and that (a) of said transfer piston (6) capable of producing all of said mechanical energy and transmit it to said energy-consuming organ (11) and that a pressure wave is formed, by connecting a pneumatic resonator (18) to one of said cold (V _C ), hot (V _E ) chambers and by adjusting it so that the pressure wave is amplified and out of phase with respect to the movement of said transfer piston (6) , so as to produce said mechanical energy and to transmit to this pneumatic resonator (18) an energy capable of compensating for its losses by friction. Method according to claim 1, characterized in that the ratio (ap / a) that is created between the section (a _P ) of said rod (6a) and that (a) of said piston (6) is between 40 and 60%. Method according to one of the preceding claims, characterized in that it is leaked out said rod (6a) of said cylinder (2) to bring it into communication with a closed volume (3) in which disposes of said energy-consuming organ (11) and exercises said elastic restoring force using pressure variations of the gas contained in said volume closed (3), following the movements of said rod (6a). Method according to one of the preceding claims, characterized in that to avoid the formation of waves at steep fronts, the section of a duct is varied tubular (18) intended to form said pneumatic resonator. Method according to claim 4, characterized in that there is a Helmholtz volume (19) at the end of said tubular conduit (18) opposite to that connected to one of said cold chambers (V _C ) hot (V _E ) of said Stirling engine. Method according to one of claims 4 and 5, characterized in that there is a part (18a) of the duct tubular (18) with variable section inside the Helmholtz volume (19). Method according to one of claims 5 and 6, characterized in that the gas contained in said Helmholtz volume (19). Method according to one of the preceding claims, characterized in that the natural frequency of said is adjusted resonator (18) by mixing gases in a proportion determined. Device for implementing the method according to claim 1, characterized in that said piston (6) is kinematically integral with said consumer organ energy (11). Device according to claim 9, characterized in what said energy consuming member (11) is made of by the moving part of an electric generator. Device according to claim 10, characterized in that said elastic restoring force exerted on said piston (6) is generated by a closed space (10, 3) filled of gas under a given pressure, a function of the frequency own desired for said piston (6) and one of which walls is formed by a portion of said rod piston (6a). Device according to one of claims 9 to 11, characterized in that four Stirling engines are connected to each other by means of four tubular resonators, the transfer pistons of two non Stirling engines adjacent working in phase and the other two in opposition phase. Device according to one of the preceding claims, characterized in that said energy consuming organ is a rotary member, connected to said piston by a connecting rod, linear guide means being associated with said piston. Device according to one of the preceding claims, characterized in that said resonator consists by two identical tubular elements arranged in opposition diametral with respect to said transfer piston. Device according to one of the preceding claims, characterized in that said tubular resonator (18) is connected to the hot chamber (V _E ) of the Stirling engine and that it is associated with heating means constituting the hot source of said Stirling engine . 12. Device according to one of claims 9 to 11, characterized in that each end of the tubular resonator (18) is connected to one of the cold rooms (V _C ) hot (V _E ) of a Stirling engine. Device according to one of Claims 9 to 11 and 15, characterized in that each end of the tubular resonator (18) is connected to one of the cold (V _C ) and hot (V _E ) chambers of a Stirling engine. Device according to one of the preceding claims, characterized in that said heating means have the form of a solar radiation collector (28, 29).

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