EP0252137B1 - Installation for harnessing thermal energy - Google Patents

Abstract

In an installation for harnessing thermal energy, a working fluid is forced during the first part of a working cycle out of a first chamber into a second chamber in which prevails a higher temperature than in the first one, and during a second part of the working cycle the working fluid is again forced back from the second chamber into the first one. Thermal energy is supplied to the working fluid during its passage from the first to the second chamber and removed during its passage from the second to the first chamber. The chambers are formed by the variable volume working chambers of piston engine units (10, 12, 14, 16) coupled to each other, working out-of-phase, which are linked to each other by fluid ducts (18, 20, 22, 24) in such a way that working fluid is forced out of a shrinking working chamber with a relatively high temperature through a first duct into an expanding working chamber with a lower temperature and at the same time working fluid is forced out of a shrinking working chamber with a lower temperature through a second duct into an expanding chamber with a higher temperature. The piston engine units work as a whole at a specific temperature level, this avoiding the occurrence of thermal insulation problems.

Description

The present invention is based on a device with the features listed in the preamble of claims 1, 7 and 8.

Such a device is known from document DE-A-32 37 841 (Eder). The known device is a thermally operated heat pump, which consists of two identical units, each with a high and low temperature working cylinder with corresponding displacement pistons, the periodic stroke movement of which is phase-shifted by 90 ^{o with} respect to one another, while the phases of the corresponding displacement pistons in both units change by 180 ^o distinguish from each other. Both units each contain an externally hermetically sealed constant volume, which is filled with compressed gas, and both high-temperature cylinders are supplied with heat at a relatively high temperature, the low-temperature cylinders with a much greater heat at low temperature, and the waste heat from all four cylinders is taken as useful heat . A counterflow heat exchanger is provided for the high-temperature cylinders, the two pipe systems of which connect the upper to the lower work rooms. The working spaces of the two low-temperature cylinders, which are separated from the displacers, are connected to each other by the separate pipe systems of a second heat exchanger. In this known device, however, a temperature difference along the cylinders must be maintained so that thermal insulation problems arise.

From the document US-A-3,115,014 (Hogan) is also already known a device that can be designed as a refrigerator and has three chambers, each contain a piston and work at a uniform temperature. However, this device does not work isochorously (constant volume), so work must be done to drive the pistons.

The present invention is accordingly based on the object of specifying a device for utilizing thermal energy by changing the state of a working fluid, which works isochorously, theoretically does not require a drive for the piston engine units and avoids heat losses and costly thermal insulation measures.

This object is achieved by the invention characterized in the claims. The present invention thus relates to a heat converter in which, in a first part of a work cycle, a heat transfer fluid from a first room to a second room in which a higher temperature prevails than in the first, is displaced and the working fluid is displaced from the second room back to the first in a second part of the working cycle, the working fluid being supplied with thermal energy during the transition from the first to the second room and thermal energy during the transition from the second to the first room is withdrawn. In one embodiment of the invention, two first working spaces lying at the higher temperature and two second working spaces lying at the lower temperature are provided, which are formed by corresponding volume-variable working spaces of coupled, phase-shifted piston machine units. The working spaces of the piston machine units are each connected to one another by fluid lines in such a way that the working fluid is displaced from a reducing working space of a relatively high temperature of a first piston machine unit through a first pipeline into an increasing working space of a relatively low temperature of a second piston machine unit and at the same time working fluid from a reducing one Low-temperature work space is displaced by a second fluid line into an increasing work space of higher temperature and that the two fluid lines are thermally coupled by a heat exchanger. This device essentially works with the proposed cyclical process. According to the invention, the piston machine units each have a housing which operates essentially at the same temperature level everywhere and contains a rotary or reciprocating piston which forms at least two working spaces with the housing and in which the temperatures are essentially the same.

Preferred embodiments of the invention include four synchronous piston engine units, one operating at the high temperature and one at the relatively low temperature and two at the medium temperature. The invention makes it possible to implement devices which operate as a heat pump and / or heat transformer and, if appropriate, also supply and / or take up mechanical work.

In the following, embodiments of the invention are described with reference explained in more detail on the drawings, while other features and advantages of the invention will be discussed.

Fig. 1

bestehend aus Fig. 1A bis 1H schematische Darstellungen von acht Arbeitsphasen einer ersten Ausführungsform der Erfindung in Form eines Drehkolben-Wärmewandlers, welche mit vier mechanisch und thermisch gekoppelten thermodynamischen Gas-Kreisprozessen arbeitet;

Fig. 2

schematische Darstellungen einiger entsprechender Arbeitsphasen des erwähnten, vorgeschlagenen Wärmewandlers,

Fig. 3 und 4

ein Druck-Zeit-Diagramm bzw. ein Volumen-Zeit-Diagramm, auf die bei der Erläuterung der Arbeitsweise des Wärmewandlers gemäß Fig. 1 Bezug genommen wird;

Fig. 5

bestehend aus Fig. 5A bis 5H Darstellungen einer als Motor verwendbaren Ausführungsform der Erfindung in verschiedenen Betriebszuständen;

Fig. 6

bestehend aus Fig. 6a bis 6h schematische Darstellungen von Arbeitsphasen einer bevorzugten, mit Hubkolbeneinheiten arbeitenden Ausführungsform der Erfindung;

Fig. 7

bestehend aus Fig. 7A bis 7C eine vereinfachte Darstellung einer Ausführungsform der Erfindung, die als Motor verwendet werden kann.

Show it:

Fig. 1

1A to 1H schematic representations of eight working phases of a first embodiment of the invention in the form of a rotary piston heat converter, which works with four mechanically and thermally coupled thermodynamic gas cycle processes;

Fig. 2

schematic representations of some corresponding working phases of the mentioned, proposed heat converter,

3 and 4

a pressure-time diagram or a volume-time diagram, to which reference is made in the explanation of the operation of the heat converter according to FIG. 1;

Fig. 5

5A to 5H representations of an embodiment of the invention that can be used as a motor in various operating states;

Fig. 6

6a to 6h show schematic representations of working phases of a preferred embodiment of the invention working with reciprocating piston units;

Fig. 7

7A to 7C, a simplified representation of an embodiment of the invention that can be used as a motor.

In the implementation of the invention, both reciprocating machine units with a reciprocating piston mounted tightly and displaceably in a cylinder, as well as any known positive displacement rotary piston machine constructions (which should also be understood to include rotary vane machines) can be used, such as pumps, compressors, etc. in manifold forms Are use. The mechanical design is therefore only discussed to the extent that it is important for the present invention. However, it should be mentioned that in the piston machine units which are used in the devices according to the invention and which in principle each take on part of the function of a displacer, there is generally no significant mechanical compression of the working fluid and no appreciable expansion of the working fluid which does the external work , takes place. However, pressure differences can occur on the pistons, so that the piston must be sealed with respect to the associated cylinder or housing by piston rings, sealing strips and the like. The forces acting on a piston due to the pressure difference can, however, be easily compensated for by mechanically coupling the pistons of two synchronously operating units.

A construction of a rotary piston machine which is well suited for realizing the invention and which is shown in a highly simplified manner in FIG. 1 contains a housing with a cylindrical inner wall, the one Forms rotor chamber in which a rotor with a cylindrical outside is arranged coaxially, which forms an intermediate space with the inner wall of the housing. The space has essentially constant radial dimensions. The rotors have sliders or "knives" which, for. B. can each consist of a strip-like projection of the rotor outside, which is connected to the rotor, extends axially with its longitudinal direction and extends radially to the housing inner wall, with respect to which is sealed by sealing strips or the like. The required, with respect to the housing, stationary seal between the rotor and the housing can then consist of a sealing slide which is mounted in a radially displaceable manner in the inner wall of the housing, lies sealingly against the cylindrical outside of the rotor and, by means of a bevelled edge of the strip-like projection, essentially corresponds with the Housing inner wall aligned position is pressed when the strip-like projection passes this seal. However, rotary piston machine designs can also be used which contain a rotary piston which is not circular in cross section.

The embodiment of the invention shown schematically in FIG. 1 can be referred to as a rotary lobe heat converter and contains four rotary lobe machine units 10, 12, 14 and 16. Unit 10 operates in a typical heat pump operating mode of the device in a relatively high temperature range H, unit 16 in a relatively low temperature range L and the units 12 and 14 in an intermediate temperature range M. The rotary lobe machine units can each contain separate, essentially cylindrical housings which can be provided on the outside with ribs or the like and / or on the inside with heat exchanger channels in order to provide a to form a large heat transfer surface and to ensure good heat transfer with an appropriate external heat transfer fluid. The housings each contain a rotor chamber with a rotor. The rotors of the units (10) to (16) can sit on a common shaft or can be driven synchronously in another way. The units 10 and 16 are thermally insulated as far as possible from the units 12 and 14. The units 12 and 14 can be accommodated in a common housing if they work at the same temperature, but the working spaces (rotor chambers) of the two units are separated in this case too.

In the embodiment according to FIG. 1, each unit has a rotor with two diametrically arranged sliders or knives 13 represented by a radial line and a stationary seal 11, indicated by a black wedge and attached to the housing inner wall, between the housing inner wall and the rotor outer surface.

Each rotary lobe machine unit has three connections for corresponding channels or pipelines carrying a gaseous working fluid, namely a connection 10a, 12a, 14a or 16a, which is located diametrically opposite the respective stationary seal, and also a connection 10b, 12b, 14b or 16b which is located immediately in front of the seal 13 when the rotors rotate in the clockwise direction, and finally a connection 10c, 12c, 14c or 16c which is located immediately behind the seal 11 in the direction of rotation located. The slider or knife 13 of the rotors are with respect to the adjacent to the stationary seal 11 openings, for. B. 10b, 10c dimensioned so that they simultaneously close these openings when sweeping.

A branching pipeline 18 connects the connections 10a, 14b and 16c. A branching pipeline 20 connects the connections 10b, 12c and 16a. A branching pipeline 22 connects the connections 10c, 12b and 14a. A branching pipeline 24 connects the connections 12a, 14c and 16b.

The part of the pipeline 18 adjacent to the connection 10a and the parts of the pipelines 20 and 22 leading from the respective branches to the connections 10b and 10c lead through a first heat exchanger 26. The part of the pipeline 20 adjacent to the connection 16a and that leading from the branch Parts of the pipelines 18 and 24 which carry the connections 16b and 16c lead through a second heat exchanger 28.

Alternatively, the parts of the lines 18 and 20 adjacent to the connections 10a and 16a cannot lead through the heat exchangers 26 and 28, but can be thermally coupled to one another by a separate heat exchanger 29.

Preferably, as indicated by dashed rectangles 30 and 32, a heat exchanger 30 and 32 are respectively between the part of the pipeline 24 adjacent to the connection 12a and the part of the pipeline 18 adjacent to the branching or between the part adjacent to the connection 14a the pipeline 22 and the part of the pipeline 20 adjacent to the branching.

The work spaces formed by the rotary piston machine units and the pipelines contain a gaseous working fluid, such as helium. In a typical mode of operation of the device according to FIG. 1 as a heat pump or chiller, the rotors of the units are driven synchronously in the clockwise direction. The unit 10 will be high quality High-temperature heat energy H supplied, the unit 16 receives low-temperature heat energy L, while the units 12 and 14 emit medium-temperature heat energy M, which is the useful heat when operating as a heat pump and generally waste heat when operating as a refrigerator.

• das Arbeitsfluid des der Rohrleitung 18 zugeordneten Systems S18 durch senkrechte Schraffur ("rot");
• das Arbeitsfluid des der Rohrleitung 20 zugeordneten Systems S20 durch rechts-schräge Schraffur ("grün");
• das Arbeitsfluid des der Rohrleitung 22 zugeordneten Systems S22 durch waagerechte Schraffur ("blau") und
• das Arbeitsfluid des der Rohrleitung 24 zugeordneten Systems S24 durch unterbrochene Kreuzschraffur ("gelb").

The heat converter according to FIG. 1 contains four gas-separated systems in which four thermodynamic gas cycle processes are shifted in relation to one another. The pressure in the different systems connected by the respective pipelines 18, 20, 22 and 24 is essentially the same, time-varying pressure. However, the pressure generally varies from system to system. In the following, the systems are each designated for simplicity by "S" with the addition of the relevant line number. In Fig. 1, the separate working fluid masses of the different systems are shown by different hatching, namely

• the working fluid of system S18 associated with pipeline 18 by vertical hatching ("red");
• the working fluid of system S20 associated with pipeline 20 by right-angled hatching ("green");
• the working fluid of the system S22 assigned to the pipeline 22 by horizontal hatching ("blue") and
• the working fluid of the system S24 assigned to the pipeline 24 by interrupted cross hatching ("yellow").

• S18 in den Einheiten 10 und 14 ;
• S20 in den Einheiten 10 und 16 ;
• S22 in den Einheiten 12 und 14 ;
• S24 in den Einheiten 12 und 16 .

In the phase shown in FIG. 1A, the working fluids of the various systems are essentially only in two units (the working fluid in the lines is neglected in the following):

• S18 in units 10 and 14;
• S20 in units 10 and 16;
• S22 in units 12 and 14;
• S24 in units 12 and 16.

In the case of a heat converter, as was proposed in the earlier patent application mentioned above, the state of the systems would correspond to the positions shown in FIG. 2 of the displacement regenerators symbolized by an oblique cross
- S18 of position I; - S20 of position II;
- S22 of position IV and - S24 of position III.

• der Arbeitsraum von S18 in der Einheit 10 ;
• der Arbeitsraum von S20 in der Einheit 16 ;
• der Arbeitsraum von S22 in der Einheit 14 und
• der Arbeitsraum von S24 in der Einheit 12 .

Fig. 1B shows the state of the systems when the rotors have rotated clockwise about 45 ^o . Part of the working space volume remains unchanged during the first 180 ^{o of} the rotation, namely

• the workspace of S18 in unit 10;
• the workspace of S20 in unit 16;
• the working area of S22 in unit 14 and
• the working room of S24 in unit 12.

In the unit 10, the working space occupied by the working fluid of the "basic" system S20 is successively smaller, so that the working fluid flows through the connection 10b, through the heat exchanger 26 and the connection 12c into the unit 12, where adjacent to the connection 12c accordingly enlarging work space is formed. At the same time, working fluid of the "blue" system S22 is displaced from the unit 12 through the connection 12b, the heat exchanger 26 and the connection 10c into the unit 10, in which a correspondingly enlarging working space is formed adjacent to the connection 10c. The working fluid of the system S20 displaced from the unit 10 into the unit 12 releases heat in the heat exchanger 26 to the working fluid of the system S22 displaced from the unit 12 into the unit 10.

In a corresponding manner, working fluid of the "red" system S18 is displaced from the unit 14 through the heat exchanger 28 into the unit 16, while at the same time working fluid of the "yellow" system S24 is displaced from the unit 16 through the heat exchanger 28 into the unit 14, so that a corresponding heat exchange can take place in the heat exchanger 28 here too.

As the temperature of the displaced working fluid changes, the pressure in the system in question also changes and, accordingly, some working fluid will flow into or out of the unit through the line in question, in which the volume of the working space of the system in question does not change.

The further course of the working cycle should be readily understandable on the basis of the above explanation when looking at FIGS. 1C to 1H. At the end the state according to FIG. 1A is reached again.

Fig. 3 shows the pressure changes that take place in the individual systems if one assumes practical values for the temperatures of the units 10, 12 + 14 and 16. The pressure in the system S18, the course of which is shown by the solid curve with an arrow, decreases between t₀ and t₁ corresponding to the transition from FIG. 1A to FIG. 1C in that working fluid of medium temperature M from the medium temperature M working Unit 14 is displaced into unit 16, in which a relatively low temperature L prevails. Between t 1 and t 2, the pressure drops relatively sharply, since during the transition from FIG. 1C to FIG. 1E, the working fluid is displaced from the unit 10, which operates at the relatively high temperature H, into the unit 12 lying at the medium temperature M, whereby a larger temperature change takes place than in the transition between 14 and 16. The temperature changes between t₂ and t₃ and between t₃ and t₄ correspond to the working phases between Fig. 1E and 1G or between Fig. 1G and Fig. 1A. The pressure curve in the other systems is represented by the curves provided with two, three or four arrows and the system name.

In FIG. 4, analogously to FIG. 3, the changes in the working volumes formed by the units 10 to 16 for the systems S18 to S24 are shown. It can be seen that the sum of the working volumes formed by the four units 10 to 16 is constant over time for each system.

The thermodynamic cycle processes running in the device according to FIG. 1 differ from the proposed process and from the so-called Vuilleumier process in that the amount of heat supplied or taken from a regenerator in a way from x to y during the backflow of y after x no longer the total mass m, but a partial mass of m is added or removed.

Since there is practically no mechanical compression of the working gas in the present devices, the drive required for the rotors is practically only that power which is necessary to overcome the frictional losses and any thermal differences in pressure.

As has already been mentioned above in connection with FIG. 1, the above-mentioned devices can serve as a heat pump or cooling machine. In a typical operating mode, the rotors rotate clockwise, heat is supplied to the units 10 and 16 operating at high H and low L temperatures, and heat is removed from the units 12 and 14 operating at medium temperature M. However, the units 12 and 14 can also be operated at different temperatures T3 and T2, where T3 can be larger or smaller than T2 without changing anything in principle in the operation of the device as a heat pump or refrigerator.

However, the devices according to FIG. 1 can also be operated in a different way than heat pumps (refrigeration machines) and also as a heat transformer or as a heat pump transformer. A total of eight operating modes are possible, which are shown in Table I below. A plus sign (+) means that thermal energy is added to the unit indicated in the first column, a minus sign (-) means that thermal energy is dissipated or taken from the unit in question.

In operating modes 1 to 4, the rotor is rotated clockwise, in operating modes 5 to 8 in a counterclockwise direction.

Operating mode 2 was explained above with reference to FIG. 1. It should be noted that T3 can be greater than, equal to or smaller than T2. T4 is larger than T3 and T2 and these are larger than T1.

Particularly advantageous heat pump or refrigerator operating modes are also 1 and 3, since in operating mode or type 1 useful heat is released at two different temperature levels T4 and T3, while in operating mode 3 cold can be generated at a relatively low level T1 and a somewhat higher level .

ist.The operating mode 8 represents a heat transformer. The unit 10 emits useful heat of the relatively high temperature 14, the unit 16 waste heat of the relatively low temperature T1, the units 12 and 14 absorb heat of the medium temperatures T3 and T2, respectively

$\text{T4>T3> / = / <T2> T1}$

is.

$\text{Betriebsart 6: T4 > T3 > T1 > T2}$

Die Wärmepumpentransformatoren eignen sich vor allem zur Wärmerückgewinnung bei Kondensationsvorgängen. Die beim Kondensieren eines Stoffes frei werdenden Kondensationswärme wird dem Wärmepumpentransformator zugeführt und durch diesen auf eine über der Kondensationstemperatur liegende Temperatur hochtransformiert, so daß sie für die Verdampfung des betreffenden Stoffes genutzt werden kann.In modes 3 and 6, the device works as a heat pump transformer. The following applies to the temperature levels

$\text{Operating mode 3: T3>T4>T2> T1.}$

$\text{Operating mode 6: T4>T3>T1> T2}$

The heat pump transformers are particularly suitable for heat recovery during condensation processes. The condensation heat released when a substance is condensed is fed to the heat pump transformer and transformed up to a temperature above the condensation temperature so that it can be used for the evaporation of the substance in question.

Further advantageous modifications result if the device according to. Fig. 1 supplemented by a compression machine KM and / or an expansion machine EM. In Fig. 1, the expansion machine EM is turned on at line 10a in line 18 and it can, for. B. can be used to supply the drive energy required to drive the rotors of the units 10 to 16. The compression machine KM is switched on at line 16a in line 20 and allows additional energy to be supplied to the system by mechanical work.

Compression or expansion machines result in the 22 types or operating modes listed in Table II, with a plus sign in the line W meaning that work is being supplied to the system via a compression machine KM, while a minus sign in this line means the removal of energy from the system means by an expansion machine EM.

FIG. 5 shows an exemplary embodiment of the present device with which thermal energy can be converted into mechanical work, in particular shaft power from a turbine. The device according to FIG. 5 contains two rotary piston machine units 710 and 712, which can be constructed essentially as it was explained in connection with FIG. 1. The units each contain three rotor chamber connections 710a, 710b and 710c or 712a, 712b and 712c, which are arranged as explained for the corresponding connections in FIG. 1. The connections 710a and 712a are connected via a line 717, which is a work-performing expansion machine, e.g. B. contains a turbine 719. Terminal 710b is connected to terminal 712c via line 721. Terminal 712b is connected to terminal 710c via line 723. The lines 721 and 723 lead through a heat exchanger 726. Furthermore, the lines 717 and 723 can be thermally coupled by a heat exchanger 728. If necessary, all or part of the gaseous working fluid flowing through line 717 can be passed through heat exchanger 726, as indicated by dashed lines.

In operation, the unit 710 receives heat energy of a relatively high temperature T _H and the unit 712 takes heat energy of a relatively low temperature T _L. The rotors of the units 710 and 712 are seated on a common shaft or are driven synchronously in some other way, whereby essentially only the mechanical friction losses need to be covered here as well, since the torques resulting from pressure differences in the units are compensated for.

5A to 5H show different operating states during one revolution of the rotors of the units 710 and 712. In units 710 and 712, four thermodynamic gas cycle processes which are phase-shifted with respect to one another take place. It is characteristic of the device according to FIG. 5 that a certain volume of the working gas only oscillates back and forth between the units 710 and 712, while another part of the volume of this "pendulum volume" is conveyed by the turbine 719 and mechanical there Does work. To explain this process, first consider the working gas located in the left half of the unit 712d between the knife 712d and the seal 712e. As the rotors rotate clockwise, the gas is displaced from the relatively cold unit 712 through line 723 into the relatively hot unit 710.

In the position according to FIG. 5c, this process is completed, ie the left half of the unit 710 now contains working gas of relatively high pressure. The knife 710d now overflows the opening 710a (FIG. 5C), so that the working gas under the relatively high pressure flows through the line 717 to the turbine 719, where it relaxes and then into the working space of the unit connected to the opening 712a 712 (Figure 5D) flows where it somewhat compresses the "brown" working gas volume contained in this workspace, which is at a relatively low temperature and has a low density, as represented by the "orange" part. In FIG. 5E, the piston 712d reaches the connection 710a, so that the outflow of working gas at a relatively high pressure occurs in front of this piston located part of the work area is terminated. This part of the working space now contains a "blue" working gas volume which has been released by the "orange" part flowing out. The working gas volume is now transferred between 5E and 5H in the part of the working space located between the seal 712e and the knife 712d, the pressure dropping as a result of the lowering of the temperature. This process is completed in FIG. 5G.

It can thus be seen that the "blue" volume only oscillates back and forth between units 710 and 712, but drives the other, "orange" part of the working gas by intermittent expansion and conveys it through the turbine to produce mechanical work there. Of course, the working gas in the "blue" and in the "orange" volume is not separated from one another, the above explanation is only intended to illustrate that a certain percentage of the working gas oscillates between units 710 and 712, while another part passes through from the first part the turbine is pushed to generate the desired shaft power. This mass fraction m _C depends on the temperature levels from T _H and T _L in units 710 and 712.

Corresponding processes take place with a corresponding phase shift with regard to the "yellow" pendulum volume and the "red" working volume. While in the above-explained process, the "orange" volume was conveyed cyclically by the "blue" or "brown" volume through the turbine, is the second to 180 ^o offset process, the "hote" gas volume from the "yellow" or "greens "Volume conveyed through the turbine.

A device of the type shown in Figure 5 can be built very compact, you can the rotary piston machines and the turbine in one and the same, for. B. housing cylindrical housing, which then has only suitable heat exchanger surfaces and, if the turbine is connected to an electrical generator, has only electrical connections for power consumption.

If the turbine 719 is replaced by a compressor or compressor in the opposite direction of delivery, the result is a heat pump or refrigeration machine.

The embodiment according to FIG. 6 contains four reciprocating piston units 810, 812, 814, 816, each of which contains a cylinder and a piston K which is displaceably mounted in the cylinder. The pistons are sealed with respect to the inner wall of the respective cylinder, e.g. B. by O-rings, since a pressure difference occurs on them during operation of the device. The pistons of the units 810 and 812 as well as the pistons of the units 814 and 816 are each rigidly coupled to one another via a gear unit G, so that they execute synchronous lifting movements in the respective cylinders.

The unit 810 works at a relatively high temperature level (H), the units 812 and 814 work at medium temperature levels M₁ or M₂, which can be the same or slightly different. Unit 816 operates at a relatively low temperature level L.

A first working fluid line 818 connects ports 810a, 812d on the opposite "outer" ends of the cylinders of the units 810 and 812 and ports 814b, 816a on the facing "inner" ends of the cylinders of the units 814 and 816, respectively connects a second working fluid line 820 connections 810b, 812a on the opposite, "inner" ends of the units 810, 812 and connections 814a, 816b on the opposite, "outer" ends of the units 814 and 816. The connections 810a and 812b and the connections 810b and parts 812a connecting the lines 818, 820 are thermally coupled to one another by a heat exchanger 826. Correspondingly, the parts of the working fluid lines 818, 820 running between the connections 814b and 816a and the connections 814a and 816b are thermally coupled to one another by a heat exchanger 828.

The working spaces connected by the line 818 in the cylinders of the units 810 to 816 form a first working medium system. The working spaces connected by the line 820 in the cylinders of the units 810 to 816 form a second working fluid system which is fluidly separated from the first. In the two systems, two different thermodynamic processes, offset by 360 ^o crankshaft rotation, take place, each of which requires a crankshaft rotation of 720 ^o . The working fluid, e.g. B. a gas such as helium, the first system occupied work spaces are shown in dotted lines in Fig. 6. The working spaces occupied by the working fluid of the other system are shown in white in FIG. 6. The pistons are hatched at an angle.

The piston preferably execute intermittent movements, ie, that they in each case during a crankshaft rotation of 90 ^o to run and remain in the reached at the end of the previous stroke movement extreme position during the next 90 ^° of crankshaft rotation in the cylinder a hub, with the pistons of one pair of units 810, 812 each move while the pistons of the other pair of units 814, 816 are at rest and vice versa. If you accept a certain reduction in efficiency, you can also work with a sinusoidal stroke movement of the pistons.

In the state shown in FIG. 6a, the pistons of the units 810 and 812 are in the middle of their upward stroke, with hot working fluid of the first system (system A punctured working spaces) assigned to line 818 in the lower part of the medium temperature level ( M₁) located unit 812 is displaced. At the same time, medium-temperature working fluid of the system assigned to line 820 (system B, white working spaces) is displaced from the upper part of unit 812 into the lower part of "hot" unit 810. The displaced working fluids of the two systems exchange heat in the 826 heat exchanger. Because of the lowering of the temperature, the pressure in system A drops between -90 ^o and +90 ^o .

At 90 ^o (Fig. 11b) the pistons have reached their extreme position.

In Breich of 90 ^o to 270 ^o, the pistons resting in the units 810 and 812 while the pistons in the units 814 and 816 according to a reciprocating movement to perform the above (Fig. 6b to Fig. 6d). The cold working fluid of system A is displaced from the "cold" unit 816 into the unit 814 located at an average temperature level M₂. This increases the pressure in system A, as the curve in FIG. 7 shows between 90 ^o and 270 ^o , but the temperature rise is relatively small because of the relatively small temperature difference between the temperature levels of the units 816 and 814. At the same time, the working fluid of system B is displaced from unit 814 into unit 816.

In the range of 270 ^o to 450 ^o, the pistons of the units 810 move downward (FIG. 6e), so that the working fluid at a medium temperature is displaced from the unit 812 in which are located on high temperature working unit 810. At the same time, hot working fluid of system B is displaced from unit 812 into unit 810. Here, too, heat is exchanged in the 826 heat exchanger. The pistons in units 814 and 816 rest between 270 and 450 ^o (Fig. 6d to 6f).

In the range between 450 and 630 ^{o of} the crankshaft rotation, the pistons in the units 810 and 812 rest while the pistons of the units 814 and 816 move upward (FIGS. 6f to 6h). The pistons of units 810 and 812 then move up again in the range between 630 ^o to 90 ^{o of} the next cycle, while the pistons in units 814 and 816 are at rest. The displacement, heating and cooling processes taking place should not require any further explanation.

If the pistons are driven in the manner described with reference to FIG. 6, the device according to FIG. 6 operates as a heat pump or cooling machine. Unit 810 is supplied with relatively high temperature heat, unit 816 receives relatively low temperature heat (cooling heat or heat to be pumped up). The units 812, 814 emit medium-temperature heat (heating or waste heat).

Reversing the direction of the heat flows and the working fluid flows z. B. by appropriate reversal of the drive direction of the individual 6 operates as a heat transformer, ie the units 812, 814 absorb heat at a medium temperature level, the unit 810 emits "highly transformed" network heat of higher temperature, while the unit 816 dissipates waste heat of a relatively low temperature must become.

The embodiment according to FIG. 6 can also be supplemented by a rotary machine analogous to FIG. B. is connected between the terminals 810a and 816b. The statements made in connection with Tables I and II also apply accordingly.

FIG. 7 shows an embodiment of the invention corresponding to FIG. 5, which can be used to generate mechanical work. The device according to FIG. 7, which is shown in FIGS. 7A to 7D in four different phases of its working cycle, contains a first reciprocating piston engine unit 910 and a second reciprocating piston engine unit 912. The unit 910 contains a piston K1 which, with the housing of the unit, has two working spaces forms, which work at a relatively high temperature level H. The second unit 912 contains a piston K2, which also forms two working spaces with the housing of this machine, but which operate at a relatively low temperature L. The pistons K1 and K2 are mechanically coupled to one another so that they each move synchronously towards a first (upper in FIG. 7) end of the associated housing or a second (lower in FIG. 7) end of the associated housing. The drive device can produce an intermittent movement, as was explained with reference to FIG. 6, but one can also work with a simus-shaped or other lifting movement.

The upper, first end of the first unit 910 is via a connection 910aa and a working fluid line 921 with a connection 912ba connected to the second, lower end of the unit 912. Furthermore, the second, lower end of the unit 910 is connected via a connection 910ba via a working fluid line 923 to a connection 912aa at the first, upper end of the unit 912. The lines 921, 923 can be thermally coupled to one another by a heat exchanger 926.

Furthermore, the first end of the first unit 910 is connected via a connection 910ab and a third working fluid line 917, which connects a working machine, such as an expansion machine, e.g. B. includes a turbine 931, connected to a port 912ba at the first end of the unit 912 and / or the second, lower end of the first unit 910 is via a port 910bb and a working fluid line 919, which a second work machine, such as an expansion machine, e.g. . B. includes a turbine 933, coupled to a port 912bb at the second end of the unit 912. Shaft power can be extracted from the turbines, i.e. 7 can serve as a motor. Otherwise, the statements made with regard to FIG. 5 apply.

If several, phase-shifted processing devices according to FIG. 7 are lined up in a row, a more uniform run can be achieved if desired. The corresponding turbines of the coupled, phase-shifted devices can then sit on a common shaft.

Claims (8)

1. Installation for harnessing thermal energy with a closed fluid circuit, in which the volume of the working fluid remains constant throughout the entire working cycle, with at least two piston engine units which form at least four working spaces with variable volume; further with a conduit system interconnecting the at least four working spaces, with a drive device for propelling pistons of the piston engines, the drive device and the conduit system being so designed that the volume of the working spaces which communicate with each other remains constant during movement of the pistons, and with a device for feed and removal of heat to and from the piston engine units, characterised in that:

   - four piston engine units are each provided with a first working space,

   - in that the devices for feed and removal of heat are so designed that the entire casing of each piston engine unit operates at a uniform temperature level, the devices for feed and removal of thermal energy being so designed that, depending on the type of operation, thermal energy is fed to (+) or removed from (-)the piston engine units according to the following table:

   

   - in that the pistons of the first and second piston engine units (10, 12; 810, 812) are propelled by the drive device synchronously and with the same phase, so that the volume of the first working space (in accordance with connection 10b or 810a) of the first piston engine unit (10; 810) changes inversely to the volume of the first working space (in accordance with connection 12c or 812b) of the second piston engine unit (12; 812), and

   - in that the pistons of the third and of the fourth piston engine units (14, 16; 814, 816) are propelled by the drive device synchronously and with the same phase, yet with offset phasing relative to the pistons of the first or second piston engine unit (10, 12; 810, 812), so that the volume of the first working space (in accordance with connection 14b or 814b) of the third piston engine unit (14; 814) changes inversely to the volume of the volume of the first working space (in accordance with connection 16c or 816a) of the fourth piston engine unit (16, 816),

   - the pistons in operational types 5 to 8 being propelled in the opposite direction to that of operational types 1 to 4.
2. Installation according to claim 1, characterised in that the piston engine units are reciprocating piston engine units (810, 812, 814, 816; Fig. 6), and in that the second working spaces are interconnected by a second conduit system (820).
3. Installation according to claim 1 or 2, characterised in that a first conduit (upper portion of 20 or 818 in Fig. 1 or Fig. 6), connecting the first working spaces of the first and of the second piston engine units (10, 12, Fig. 1; 810, 812, Fig. 6), and a second conduit (upper portion of 22 or 820) connecting the second working spaces of the first and of the second piston engine units (10, 12; 810, 812), are thermally coupled by a first heat-exchanger (26, 826), and in that a third conduit (lower portion of 18 or 818) connecting the first working spaces of the third and of the fourth piston engine units (14, 16 or 814, 816), and a fourth conduit (lower portion of 24 or 820) connecting the second working spaces of the third and of the fourth piston engine units (14, 814; 16, 816), are thermally interconnected by a second heat-exchanger (28, 828).
4. Installation according to claim 1, characterised in that the piston engine units are rotary piston engine units (10, 12, 14, 16 in Fig. 1), whose casings each form a substantially cylindrical rotor chamber and contain as a piston a rotarily-disposed, substantially cylindrical rotor; in the the rotor has at least two elements (13) providing a seal with respect to the casing, in that at least one seal (11), stationary with respect to the casing, is provided between casing and rotor; in that each rotor chamber contains at least one set of three connections (10a, 10b, 10c...) for working fluid conduits, of which the first (10a) in each case is at an angular distance from the adjacent seal (11) stationary on the casing which is equal to 180^o divided by the number of seals, and in that the second and third connections (10b, 10c), with a given rotational direction of the rotor, lies directly in front of or directly behind an associated seal (11) stationary with the casing; in that the first connection (10a) of the first rotary piston engine unit (10) is connected by a branching first working fluid conduit (18) to the first connection (14b) of the third rotary piston engine unit (14) and to the third connection (16c) of the fourth rotary piston engine unit (16); in that the first connection (12a) of the second rotary piston engine unit (12) is connected by a branching second working fluid conduit (24) to the second connection (16b) of the fourth rotary piston engine unit (16), and to the third connection (14c) of the third rotary piston engine unit (14); in that the first connection (14a) of the third rotary piston engine unit (14) is connected by a branching third working fluid conduit (22) to the second connection (12b) of the second rotary piston engine unit (12) and to the third connection (10c) of the first rotary piston engine unit (10), and in that the first connection (16a) of the fourth rotary piston engine unit (16) is connected by a branching fourth working fluid conduit (20) to the second connection (10b) of the first rotary piston engine unit (10), and to the third connection (12c) of the second rotary piston engine unit (12).
5. Installation according to claim 4, characterised in that there is disposed, in the portion of the first working fluid conduit (18) adjacent to the first connection (10a) of the first rotary piston engine unit (10), and/or in the portion of the fourth working fluid conduit (20) adjacent to the first connection (16a) of the fourth rotary piston engine unit (16), a compression engine absorbing work, or an expansion engine generating work.
6. Installation according to claim 5, characterised in that the devices for feed and removal of thermal energy are so designed that, depending on the type of operation, thermal energy is fed to (+) or removed from (-)the piston engine units according to the following table, a plus sign in the line (W) meaning that work is being fed to the system via a compression engine (KM), whereas a minus sign in this line means the removal of energy from the system by an expansion engine (EM):

   
7. Installation for harnessing thermal energy with a closed fluid circuit, in which the volume of the working fluid remains constant throughout the entire working cycle, with at least two piston engine units which form at least four working spaces with variable volume; further with a conduit system interconnecting the at least four working spaces, with a drive device for propelling pistons of the piston engines, the drive device and the conduit system being so designed that the volume of the working spaces which communicate with each other remains constant during movement of the pistons, and with devices for feed and removal of heat to or from the piston engine units, characterised in that:

   - the two piston engine units are rotary piston engine units (710, 712), whose casings each form a substantially cylindrical rotor chamber, and contains as a piston a rotarily-disposed substantially cylindrical rotor which contains at least one pair of diametral elements providing a seal with respect to the casing, and at least one stationary seal with respect to the rotor, and at least one set of three connections (710a, 710b, 710c; 712a, 712b, 712c) for working fluid conduits, of which the first (710a) is at an angular distance from each adjacent seal stationary on the casing which is equal to 180^o divided by the number of seals, and in that the second and third seals (710b, 710c; 712b, 712c), with a given rotational direction of the rotor, lie directly in front of or directly behind an associated seal stationary on the casing,

   - in that the devices for feed and removal of heat are so designed that the entire casing of each rotary piston engine unit each operates at a uniform temperature level,

   - in that the first connection (710a) of the first rotary piston engine unit (710) is connected to the first connection (712a) of the second rotary piston engine unit (712) by a first working fluid conduit (717), which contains a compression or expansion engine; in that the second connection (710b) of the first rotary piston engine unit (710) is connected by a second working fluid conduit (721) to the third connection (712c) of the second rotary piston engine unit (712), and in that the third connection (710c) of the first rotary piston engine unit (710) is connected by a third working fluid conduit (723) to the second connection (712b) of the second rotary piston engine unit (712),

   - in that the rotors of the first and of the second rotary piston engine unit are propelled by the drive device synchronously and with the same phase, so that the volume of the first working space (in accordance with connection 710b) of the first rotary piston engine unit changes inversely to the volume of the first working space (in accordance with connection 712c) of the second rotary piston engine unit (712), and the volume of the second working space (in accordance with connection 710c) of the first rotary piston engine unit (710) changes inversely to the volume of the second working space (in accordance with connection 712b) of the second rotary piston engine unit (712).
8. Installation for harnessing thermal energy with a closed fluid circuit, in which the volume of the working fluid remains constant throughout the entire working cycle, with at least two piston engine units which form at least four working spaces with variable volume; further with a conduit system interconnecting the at least four working spaces, with a drive device for propelling pistons of the piston engines, the drive device and the conduit system being so designed that the volume of the working spaces which communicate with each other remains constant during movement of the pistons, and with devices for feed and removal of heat to or from the piston engine units, characterised in that:

   - the piston engine units are reciprocating piston engine units (910, 912), whose casings each form a working cylinder which contains a piston (K1 or K2), and has at a first and and at a second end opposite said first end connections (910aa, 910ab, 910ba, 910bb or 912aa, 912ab; 912ba, 912bb) for working fluid conduits (917, 919, 921, 923);

   - in that the devices for feed and removal of heat are so designed that the entire casing of each reciprocating piston engine unit operates at a uniform temperature level,

   - in that the pistons (K1, K2) of the two reciprocating piston engine units (910, 912) are propelled by the drive device synchronously and with the same phase, in such a way that they both move synchronously to the first or to the second end;

   - in that a connection (910ab) on the first end of the first piston engine unit (910) is connected to a connection (912ba) on the first end of the second piston engine unit (912) by a first working fluid conduit (917), which contains a compression or expansion engine (919);

   - in that a connection (910bb) on the second end of the first piston engine unit (910) is connected by a second working fluid conduit (919) containing a compression or expansion engine (933), to a connection (912bb) on the second end of the second piston engine unit;

   - in that a connection (910aa) on the first end of the first piston engine unit (910) is connected by a third working fluid conduit (921) to a connection (912ba) at the second end of the second piston engine unit (912),

   - and in that a connection (910ba) on the second end of the first piston engine unit is connected by a fourth working fluid conduit (923) to a connection (912aa) on the first end of the second piston engine unit.

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