EP2820299B1 - Liquid piston arrangement with a plate-type heat exchanger for the quasi isothermal compression and expansion of gases - Google Patents

Description

The invention relates to a liquid piston arrangement with plate exchanger for the quasi-isothermal compression and expansion of gases.

The high-pressure air storage has been known since the 19th century, but has so far prevailed only in specific applications. Recently, however, interest in this technology has increased as it seeks ways of using decentralized renewable energy and supporting existing networks with local storage.

• DE 34 08 633 A1 ,
• US 586 100 A ,
• EP 2 273 119 B1 ,
• Eidgenössisches Department für Umwelt, Verkehr, Energie und Kommunikation UVEK, Bundesamt für Energie BFE, Schlussbericht Mai 2004, Einsatz von Druckluftspeichersystemen, I. Cyphelly, A. Rufer, Ph. Brückmann, W. Menhardt, A. Reller, Cyphelly & Co, Champ de Rive, CP 18, 2416 Les Brenets, DIS-Projekt Nr. 100406, DIS-Vertrags Nr. 150504,
• Eidgenössisches Department für Umwelt, Verkehr, Energie und Kommunikation UVEK, Bundesamt für Energie BFE, Jahresbericht 2004, 27. Dezember 2004, Projekt Machbarkeit des Druckluftspeicherkonzeptes BOP-B, Philipp Brückmann, Iván Cyphelly, Markus Lindegger, Bahnhofstr. 17, 7260 Davos Dorf, BFE-Projekt-Nr. 100985, BFE-Vertrag-Nr. 151155,
• Eidgenössisches Department für Umwelt, Verkehr, Energie und Kommunikation UVEK, Bundesamt für Energie BFE, Jahresbericht 2005, 2. Dezember 2005, Projekt Machbarkeit des Druckluftspeicherkonzeptes BOP-B, Philipp Brückmann, Iván Cyphelly, Markus Lindegger, Bahnhofstr. 17, 7260 Davos Dorf, BFE-Projekt-Nr. 100985, BFE-Vertrag-Nr. 151155, und
• Eidgenössisches Department für Umwelt, Verkehr, Energie und Kommunikation UVEK, Bundesamt für Energie BFE, Druckluftspeicherung: Optimierung/Ausmessung bestehendes Projektmuster, Schlussbericht, 01.06.2007, Philipp Brückmann, Brückmann Elekotronik (Projektleitung), Bahnhofstr. 17, 7260 Davos Dorf, Iván Cyphelly, Cyphelly & Cie (Versuche und Bericht), POB18, 2416 Les Brenets.

Conventional arrangements for the compression and expansion of gases are known from the following publications:

• DE 34 08 633 A1 .
• US 586 100 A .
• EP 2 273 119 B1 .
• Federal Department of the Environment, Transport, Energy and Communications DETEC, Swiss Federal Office of Energy SFOE, Final Report May 2004, Use of Compressed Air Storage Systems, I. Cyphelly, A. Rufer, Ph. Brückmann, W. Menhardt, A. Reller, Cyphelly & Co, Champ de Rive, CP 18, 2416 Les Brenets, DIS project no. 100406, DIS contract no. 150504,
• Federal Department of the Environment, Transport, Energy and Communications DETEC, Swiss Federal Office of Energy SFOE, Annual Report 2004, 27 December 2004, Project Feasibility of the compressed air storage concept BOP-B, Philipp Brückmann, Iván Cyphelly, Markus Lindegger, Bahnhofstr. 17, 7260 Davos Dorf, SFOE project no. 100985, SFOE contract no. 151,155,
• Federal Department of the Environment, Transport, Energy and Communications DETEC, Swiss Federal Office of Energy SFOE, Annual Report 2005, 2 December 2005, Project feasibility of the compressed air storage concept BOP-B, Philipp Brückmann, Iván Cyphelly, Markus Lindegger, Bahnhofstr. 17, 7260 Davos Dorf, SFOE project no. 100985, SFOE contract no. 151155, and
• Federal Department of the Environment, Transport, Energy and Communications DETEC, Swiss Federal Office of Energy SFOE, compressed air storage: optimization / measurement of existing project samples, final report, 01.06.2007, Philipp Brückmann, Brückmann Elekotronik (project leader), Bahnhofstr. 17, 7260 Davos village, Iván Cyphelly, Cyphelly & Cie (experiments and report), POB18, 2416 Les Brenets.

High-pressure air storage uses the energy contained in compressed air. For example, at times when more power is produced than consumed, the excess energy can be used to pump air under pressure into a storage tank. When electricity is needed, the energy stored in the compressed air is re-absorbed into other forms of energy, such as energy. As electric power, converted or machines or vehicles are driven directly.

Compaction and relaxation in higher pressure ranges (100 to 300 bar) are still lossy processes, since the coupling between Heating and pressure increase (or between cooling and pressure reduction) prevents efficient operation and only intermittently intercooled adiabatic processes can be strung together. The multi-stage compressors with a variety of valves and topologically related dead spaces thus achieve energy efficiencies that exceed 50% barely, and this with considerable effort, such. B. with high pressure suitable heat exchangers for each stage. These low efficiencies complicate the technique of compression and relaxation for energy storage in high pressure vessels.

To eliminate this problem, it requires a heat exchange during the pressure change, so that an approximately isothermal behavior can be enforced, and this combined with an elimination of the dead space. There are known in this regard problem solutions that limit the temperature fluctuations due to indirect heat exchange by spray injection in screw compressors, scroll compressors or liquid reciprocating compressors, in which case the heat first passes to the drops and then passes to an outside exchanger. However, the return of the spray precipitate from the high-pressure region is technically complicated. In motorized operation (relaxation), an additional fluid circuit must ensure the spray, which in turn must be discarded in the exhaust to return to the circuit.

A conventional liquid piston arrangement for compressing and relaxing gases with a liquid piston, which is embodied by a liquid level formed by a liquid in a high-pressure space, is known from the publication EP 2 273 119 B1 known. Other conventional liquid piston assemblies are in the references DE 10 2008 042 828 A1 . WO 2010/128 224 A1 and DE 44 30 716 A1 described.

The invention is therefore based on the object to provide a liquid piston arrangement for approximately isothermal processes in the higher pressure range.

The problem underlying the invention is solved by the features of claim 1.

Fig. 1

eine Flüssigkolbenanordnung mit zwei Flüssigkolben, zwei hydrostatischen Regeleinheiten und einem Niederdruckgenerator bzw. Entspanner;

Fig. 2A bis 2D

die Flüssigkolbenanordnung aus Fig. 1 während des Betriebs;

Fig. 3A bis 3D

eine Flüssigkolbenanordnung mit Messkolben als Mitnahme eines Vordruckkolbens während des Betriebs;

Fig. 4

einen Schnitt durch ein Blechpaket aus Fig. 3A;

Fig. 5

eine Flüssigkolbenanordnung mit zwei Gegentaktelementen im Verbundbetrieb;

Fig. 6

den Drehmomentverlauf als Resultat des Verbundbetriebs der Flüssigkolbenanordnung aus Fig. 5;

Fig. 7A bis 7D

eine Flüssigkolbenanordnung mit einem einzigen Weichenventil während des Betriebs; und

Fig. 8

einen Teil einer Flüssigkolbenanordnung mit einer Wärmetauscherrolle gemäß einem Ausführungsbeispiel der Erfindung.

The invention will be explained in more detail below by way of example with reference to the drawings. In these show:

Fig. 1

a liquid piston arrangement with two liquid pistons, two hydrostatic control units and a low pressure generator or expander;

Fig. 2A to 2D

the liquid piston assembly Fig. 1 during operation;

Fig. 3A to 3D

a liquid piston assembly with a measuring piston as entrainment of a pilot piston during operation;

Fig. 4

a section through a laminated core Fig. 3A ;

Fig. 5

a liquid piston arrangement with two push-pull elements in the combined operation;

Fig. 6

the torque curve as a result of the combined operation of the liquid piston assembly Fig. 5 ;

Figs. 7A to 7D

a liquid piston assembly with a single point valve during operation; and

Fig. 8

a part of a liquid piston assembly with a heat exchanger roller according to an embodiment of the invention.

The liquid piston arrangements described below and shown schematically in the figures have liquid pistons which each contain a laminated core with fixed distances between the sheets. In particular, the laminated core fills the entire rectangular liquid piston working space. The free surface of the liquid between the sheets embodies the piston. The laminated core is displaceable in order to move the valve cone fastened to the upper package side surface without clearance in the metal sheets and to guide it for a gap-free circuit between low-pressure chamber and high-pressure chamber. In the closed state, therefore, no air dead space remains in the high-pressure chamber. The laminated core absorbs the heat generated during the working cycles. Since the laminated core is completely lapped at each stroke, it remains close to the temperature of the liquid. From the liquid, the heat is released through a heat exchanger to the environment.

One embodiment provides that the rectangular high-pressure chamber is arranged obliquely, whereby the low-pressure valve cone can shut off the working space of a low-pressure piston with the high-pressure chamber in the closed position dead volume and enforces the position of the high-pressure valve flap at the upper corner of the laminated core a funnel-like inflow during compression and thus prevents swirling cross currents.

In particular, the liquid piston arrangements described here prevent any dead space, make high-pressure heat exchangers superfluous and ensure process-oriented switching accuracy.

The plate exchangers described below are inserted in a respective kinematic chain whose losses wave / air or electricity / air does not negate the achieved efficiency again. There are topological designs are provided which avoid in particular air pockets by turbulence and high accelerations, friction by lateral forces and aging, by means of harmonious interaction of the elements of the "liquid connecting rod".

1. 1. Die Schaltung in Luft soll leckfrei sein, vorzugsweise mittels Sitzventilen zwischen Hochdruckzylinder und Vordruckraum sowie druckseitig zum Speicher, und außerdem vollständig totraumfrei bleiben, um Verwirbelungen zu vermeiden.
2. 2. Die Integrierung eines Niederdruckzylinders oder einer anderen Vordruckerzeugung sollen vorgesehen sein, denn eine ununterbrochene Kompression/Entspannung von 1 bar auf 200 bar würde gewaltige Ausmaße bedingen (diese einstufige Ausführung ist jedoch dank Platten-Tauscheffekt durchaus möglich).
3. 3. Eine Untersetzung zwischen Welle und Kolbenbewegung soll gesichert sein, da die Hubfrequenz 1 bis 2 Hz nicht überschritten wird und die Welle mindestens 1500 Upm aufweisen sollte.
4. 4. Die Untersetzung sowie die Hubbewegung sollen auf Lösungen verzichten, die Querkräfte und große Lagerkräfte bedingen (bei den langsamen Bewegungen der Kolben würde schon bei bescheidenen Leistungen die Wälzlager überfordert).
5. 5. Um die Flüssigkeit im Betrieb aufzubereiten, soll das Pleuel/Kolben-Volumen periodisch über einen Tank drucklos umgewälzt werden, damit Blasen, Staub und Feuchtigkeit entfernt werden können.
6. 6. Der Außentauscher soll niederdruckseitig angeschlossen sein, da geringstmögliche Temperaturdifferenzen mit der Umwelt angestrebt werden, die über Hochdruck-Rohrtauscher kaum mit vernünftigem Aufwand zu erzielen sind. Außerdem kann somit ein einziger Außentauscher auch mehrkolbige Anlagen bedienen.
7. 7. Die Kolben-Bewegungsumsteuerung soll mit geringen Beschleunigungen geschehen, vornehmlich gemäß einer vorgegebenen Geschwindigkeitskurve, die eine Glättung der Druck- bzw. Drehmomentpulsationen bei Verbundanordnungen ermöglicht.
8. 8. Es soll verhindert werden, dass bei Lösungen mit hin- und hergehenden Kolben ein Totraum entsteht, der im Betrieb nicht genügend durchspült wird und somit Verunreinigungen und Wärme speichert.

The in the Fig. 1 to 8 In particular, one or more or even all of the following conditions are satisfied by liquid piston arrangements shown:

1. 1. The circuit in air should be leak-free, preferably by means of seat valves between the high-pressure cylinder and Vordruckraum and the pressure side to the memory, and also remain completely free of dead space to avoid turbulence.
2. 2. The integration of a low-pressure cylinder or other form generation should be provided, because a continuous compression / relaxation of 1 bar to 200 bar would require enormous proportions (this single-stage design is quite possible thanks to plate exchange effect).
3. 3. A reduction between shaft and piston movement should be ensured, since the stroke frequency 1 to 2 Hz is not exceeded and the shaft should have at least 1500 rpm.
4. 4. The reduction as well as the lifting movement should dispense with solutions that require lateral forces and large bearing forces (in the case of slow movements of the pistons, the rolling bearings would be overwhelmed even with modest performances).
5. 5. In order to process the liquid during operation, the connecting rod / piston volume should be periodically circulated through a tank without pressure, so that bubbles, dust and moisture can be removed.
6. 6. The outer exchanger should be connected to the low pressure side, since the lowest possible temperature differences with the environment are sought, which can hardly be achieved with high effort tube exchanger with reasonable effort. In addition, therefore, a single outdoor exchanger can also serve mehrkolbige systems.
7. 7. The piston movement reversal should be done with low accelerations, primarily according to a predetermined speed curve, which allows smoothing the pressure or torque pulsations in composite arrangements.
8. 8. It is to be prevented that in solutions with reciprocating piston dead space is created, which is not sufficiently flushed during operation and thus stores impurities and heat.

Fig. 1 schematically shows a liquid piston assembly 1 for the quasi-isothermal compression and relaxation of gases with two liquid pistons 2a, 2b. Due to the same structure of the two liquid pistons 2 a, 2 b, the mutually corresponding elements of the liquid piston 2 a, 2 b, such. As high pressure spaces, laminated cores, etc., with number words ("first Element "or" second element "), as is the case in the subsequent patent claims, but for the sake of clarity the number words are omitted in the description.

The liquid pistons 2 a, 2 b each include a high-pressure chamber 3 a, 3 b and a laminated core 4 a, 4 b stored in the high-pressure chamber 3 a, 3 b. The laminated cores 4a, 4b each consist of a plurality of sheets, which are arranged in particular parallel to each other. Further, the sheets of a laminated core 4a, 4b may be arranged equidistantly and in particular have a distance between two adjacent sheets in the range of 0.3 to 0.8 mm. A liquid level 5a, 5b in the respective high-pressure chambers 3a, 3b and between the sheets of laminated cores 4a, 4b represents the respective piston.

The laminated cores 4a, 4b are slidably mounted in the high-pressure chambers 3a, 3b in order to forcibly control the low-pressure valve poppets 6a, 6b fastened to their upper sides, as a result of which low-pressure valves 7a, 7b are opened or closed. The undersides of the laminated cores 4a, 4b are fastened to spring-loaded control pistons 8a, 8b, by means of which the laminated cores 4a, 4b can be displaced in the high-pressure spaces 3a, 3b.

The liquid piston assembly 1 further comprises a low pressure generator or expander 10, the z. B. can be configured as a reversible scroll unit or rotor rotor. The low pressure generator or expander 10 is connected via an air line 11 to the low pressure valves 7a, 7b in order to generate a form in the high pressure chambers 3a, 3b can. The other connection of the low pressure generator or expander 10 is equipped with a suction filter and / or muffler 12. The low-pressure generator or expander 10 is mounted on a shaft 13 and is driven by this.

Furthermore, two variable, working in push-pull hydrostatic units 14a and 14b are provided, which can also be driven by the shaft 13 or can drive the shaft 13 during engine operation. The hydrostatic units 14a, 14b are connected via lines 15a, 15b to the high-pressure chambers 3a, 3b, so that they can feed liquid into the high-pressure chambers 3a, 3b or take them out. In addition, the hydrostatic unit 14a controls the spool 8b via a pipe, and the hydrostatic unit 14b controls the spool 8a via a pipe 16b. When the control pistons 8a, 8b are subjected to a high pressure via the lines, they press the laminated cores 4a, 4b downwards and thereby open the low-pressure valves 7a, 7b. In contrast, non-pressurized lines due to the springs contained in the control piston 8a, 8b closed low-pressure valves 7a, 7b result.

In an actuator 20, a speed command 21 can be input, from which the actuator 20 together with the respective rotational speed ω of the shaft 13 and the delivery volume setting α of the hydrostatic units 14a, 14b, the effective liquid feed or removal through the lines 15a, 15b calculated wherein the abutment of the respective high-pressure valve flap 31a, 31b on the magnetic coil 33a or 33b supplies the essential "reset" signal.

As Fig. 1 2, the hydrostatic units 14a, 14b are connected to a container 22 via filters 23a, 23b, an outer heat exchanger 24 and check valves 25. As shown in FIG.

In addition to the low-pressure valves 7a, 7b, high-pressure valves 30a, 30b are arranged on the high-pressure chambers 3a, 3b. The high-pressure valves 30a, 30b are made of high-pressure valve flaps 31a, 31b, which are arranged in cavities 32a, 32b and can be controlled by magnetic coils 33a, 33b. Connections from the high-pressure valves 30a, 30b to a storage space 35 are provided via lines 34a, 34b.

The operation of the liquid piston assembly 1 will be described below with reference to Fig. 2A to 2D explains, between two modes of operation of the liquid piston assembly 1 is distinguished. In a first operating mode, schematically in the FIGS. 2A and 2B is shown, gas is compressed with the application of energy. In a second operating mode, schematically in the Fig. 2C and 2D is shown, the gas is relaxed again and the energy released thereby converted into a movement of the shaft 13.

In the Fig. 2A to 2D As with all other figures, triangles symbolize the flow direction of the liquid in the respective lines. Filled triangles indicate a high pressure area, unfilled triangles a low pressure area. Flowless lines are shown in dashed lines.

In the in the FIGS. 2A and 2B shown compression of the gas, such as air, a form in the respective high pressure chamber 3a, 3b is first created with the help of the pressure provided by the low pressure generator or expander 10 pressure. Subsequently, this pressure is increased by pumping liquid into the high-pressure chamber 3a, 3b. As soon as the pressure prevailing in the storage space 35 has been reached, the high-pressure valve 30a, 30b opens and an increase in pressure in the storage space 35 can be achieved.

The FIGS. 2A and 2B show the two positions of the controlled by the control piston 8a, 8b laminated cores 4a, 4b. In Fig. 2A is the laminated core 4a in the upper position, so that the low-pressure valve 7a is closed, whereas the laminated core 4b is in the lower position and the low-pressure valve 7b is opened accordingly. In Fig. 2B the positions of the laminated cores 4a, 4b are exactly reversed.

Fig. 2A shows that the hydrostatic unit 14a via the filter 23a promotes liquid from the container 22 and the liquid pumped further into the high-pressure chamber 3a, which there has a rising liquid level 5a result. In the preceding working phase was in the high pressure chamber 3 a by means of the low pressure generator or expander 10, a form of z. B. 1 to 6 bar generated. Due to the rising liquid level 5a, this pressure now increases successively. As soon as the same pressure as in the storage space 35 prevails in the high-pressure chamber 3a, the high-pressure valve 30a opens and an injection into the storage space 35 can take place.

At the same time, the liquid contained in the high pressure space 3b is pumped from the hydrostatic unit 14b via the heat exchanger 24 into the tank 22. Since the low-pressure valve 7b is opened, prevails in the high pressure chamber 3b of the low pressure generator or expander 10 generated form.

Subsequently, the control pistons 8a, 8b are switched so that the positions of the sheet metal pawls 4a, 4b and thus the low-pressure valve cone 7a, 7b as in Fig. 2B shown result.

While in Fig. 2B shown working phase, the previously pumped into the high-pressure chamber 3a liquid is pumped from the hydrostatic unit 14a again and flows through the heat exchanger 24 into the container 22. About the low pressure valve 7a, the low pressure generator or expander 10 generates the form in the high pressure chamber 3a.

Meanwhile, in the high-pressure space 3b, the liquid level 5b rises due to the liquid supplied from the tank 22 from the hydrostatic unit 14b. As soon as the pressure of the storage space 35 is reached in the high pressure chamber 3b, the high pressure valve 30b opens and the gas in the storage space 35 is further compressed.

After that the one of the two in the FIGS. 2A and 2B shown working phases repeated cycle, whereby a desired pressure in the storage space 35 in the range of for example 200 to 300 bar can be generated. The energy that has been used to generate this pressure can be converted into a movement of the shaft 13 in the so-called motor operation.

The two working phases of the engine operation are in the Fig. 2C and 2D shown. In Fig. 2C the control piston 8a pushes the laminated core 4a into the upper position, so that the low-pressure valve 7a is closed, whereas the laminated core 4b is in the lower position and the low-pressure valve 7b is accordingly opened. In Fig. 2D the positions of the laminated cores 4a, 4b are exactly reversed.

On the back of the high-pressure valve flaps 31 a, 31 b steel disks are mounted, through which the high pressure valves 30 a, 30 b can be influenced by means of the magnetic coils 33 a, 33 b in such a way that as long as a current flows through the connecting wires of the magnetic coils 33 a, 33 b High-pressure valve flaps 31a, 31b are held in the open position after opening in order to maintain the pre-pressure by means of precise metering.

In the engine operation can be supplied to the high-pressure chambers 3a, 3b by the targeted opening and closing of the high pressure valves 30a, 30b of the pressure previously generated in the storage space 35. As Fig. 2C shows, by the high pressure generated in the high-pressure chamber 3a, the shaft 13 is driven via the hydrostatic unit 14a. The liquid which is thereby pressed out of the high-pressure space 3a flows via the hydrostatic unit 14a and the outer heat exchanger 24 into the container 22. At the same time, the hydrostatic unit 14b pumps liquid from the container 22 into the high-pressure space 3b in which the low-pressure generator or expander 10 generates the form via the opened low-pressure valve 7b. The energy that is used to operate the hydrostatic unit 14b and the low-pressure generator or expander 10 ultimately comes from the energy that has been transferred from the hydrostatic unit 14a to the shaft 13. Furthermore, other machines can be driven by the shaft 13, for example, a generator for power generation.

While in Fig. 2D shown working phase, the functionalities of the two liquid pistons 2a, 2b exactly the reverse as in Fig. 2C , The targeted opening and closing of the high-pressure valve 30b creates a high-pressure in the high-pressure space 3b, which presses back the liquid previously pumped by the hydrostatic unit 14b into the high-pressure chamber 3b. As a result, the hydrostatic unit 14b converts a part of the energy stored in the storage space 35 into a movement of the shaft 13. Part of this energy, in turn, is provided by the hydrostatic unit 14a and the low pressure generator or expander 10 used to pump liquid from the container 22 in the high-pressure chamber 3a and to generate the form in the high-pressure chamber 3a. Subsequently, the from the in the Fig. 2C and 2D shown working cycle repeated cycle.

The laminated cores 4a, 4b in the high-pressure chambers 3a, 3b act as heat exchangers and ensure an approximately isothermal operation even in higher pressure ranges. The resulting in the compression and relaxation temperature fluctuations are transmitted in the high-pressure chambers 3a, 3b of the air to the metal plates of the laminated cores 4a, 4b and from these to the liquid that flows around the laminated cores 4a, 4b. From the liquid, the temperature fluctuations are finally discharged via the outer heat exchanger 24 to the environment.

In the Fig. 1 shown liquid piston assembly 1 is a basic version of a push-pull circuit that meets all the above conditions without the volumetric flask, but with two hydrostatic units 14a, 14b and with the separate low pressure generator or expander 10, which is not the optimum in terms of price and efficiency (in a combined operation it would be four hydrostatic units, with a single low pressure generator or expander would suffice). From this basic version, all further liquid piston arrangements described below can be derived.

Fig. 3A schematically shows a liquid piston assembly 50 with two volumetric flasks as entrainment of a Vordruckkolbens, whereby a second hydrostatic unit and the low pressure generator or expander are dispensable, but with the aid of a reversing valve and a circulation pump in the processing unit, as described below becomes. Various operating states of the liquid piston assembly 50 are in the Fig. 3A to 3D shown.

Similar to the liquid piston assembly 1 from Fig. 1 The liquid piston arrangement 50 has two liquid pistons 51a, 51b, each of which comprises a high-pressure chamber 52a, 52b and a laminated core 53a, 53b mounted in the high-pressure chamber 52a, 52b.

In the present embodiment, the laminated cores 53a, 53b of sheet stacks, which are mounted by means of spring-loaded control piston 54a, 54b in the longitudinal axis slidably in the high-pressure chambers 52a, 52b. The movement of the laminations 53a, 53b determines the movement of low pressure poppets 55a, 55b and thus the opening and closing of low pressure valves 56a, 56b because the low pressure poppets 55a, 55b are fixedly connected to the respective stack of laminations on the upper stacking surface.

The metal plates of the laminated cores 53a, 53b may be provided with a spacing notation 57a, 57b or other inserts, by which the distance between the metal plates is specified. In particular, the distances between two adjacent sheet metal plates in the laminated cores 53a, 53b may be constant. The metal plates may be aligned parallel to each other, and the distance between adjacent metal plates is in particular between 0.3 and 0.8 mm. The laminated cores 53a, 53b may be in the form of a rectangular prism, as shown schematically in FIG Fig. 4 showing a section of the laminated core 53a in the cylinder block 58a along the in Fig. 3A drawn line A-A ', ie a section perpendicular to the longitudinal axis of the laminated core 53a, shows. The laminated cores 53a, 53b fill the respective high pressure chamber 52a, 52b perpendicular to the longitudinal axis, ie in the in Fig. 4 shown level, completely off.

The low-pressure valves 56a, 56b mutatis mutandis connect the pre-pressure chambers 59a, 59b of the pilot pressure piston 60 with the respective high-pressure chambers 52a, 52b. The cylinder blocks 58a, 58b in which the respective high pressure spaces 52a, 52b are located also include the seat of the high pressure valve flaps 65a, 65b of the high pressure valves 66a, 66b. The high-pressure valve flaps 65a, 65b are arranged in a respective cavity 67a, 67b together with holding magnet coils 68a, 68b and are guided coaxially therefrom.

The respective liquid piston mirror 70a, 70b is moved by a measuring piston 72a, 72b coupled to the liquid connection 71a, 71b, which also carries the preliminary pressure piston 60 (the measuring pistons 72a, 72b and the primary pressure piston 60 are connected to one another via a rod) and a complete one at each stroke Flushing of the respective laminated core 53a, 53b causes and thus an indirect exchange with an outer heat exchanger 75. This stream flows through a 7/2-way switch valve 76a, 76b, the pressure-free circuit with the outer heat exchanger 75, a filter 77 and a Reservoir 78 operated. This arrangement allows a perfect replacement of the piston fluid at each stroke, since these depending on the direction of flow either directly from - as in Fig. 3A shown on the left side - sheet stack 53a to the volumetric flask 72a via an exchange volume 80a and a check valve 81a flows when moving the volumetric flask 72a to the left (low pressure compression), according to the illustrated slide position of the 7/2-way switch valve 76a, or at high pressure compression - as in Fig. 3B shown on the right side by way of example - from the volumetric flask 72b back into the high-pressure chamber 52b via a check valve 82b, wherein the slide of the 7/2-way switch valve 76b is pushed into the pressure-side blocking position for the exchange volume 80b and thus a pump 85 can circulate the fluid of the exchange volume 80b thanks to the release of the corresponding connections during this stroke (the circulation in one of the exchange volumes 80a, 80b contained by means of the pump 85 is in the Fig. 3A to 3D represented by dashed lines filled triangles.).

At the in Fig. 3A shown working phase is a dead space on the pre-pressure chamber 59a arranged suction / exhaust valve 86a closed to produce the required form in the pre-pressure chamber 59a. At the same time, a suction / exhaust valve 86b arranged dead-space-free on the pre-pressure space 59b is opened so that a pressure equalization in the pre-compression space 59b with the environment can take place. The suction / exhaust valves 86a, 86b are each opened and closed by means of a control piston.

The volumetric pistons 72a, 72b are inserted in the respective hydraulic path between the controllable hydrostatic unit 87 and the 7/2-way diverter valve 76a, 76b and thus obey the mechanically or electronically impressed modified sinusoidal velocity profiles indicating the acceleration of the liquid piston mirrors 70a, Limit 70b.

The operating fluid should preferably have a very low vapor pressure, such as. For example, water or an ionic liquid from the methylimidazolium group and in particular the hydrophobic ionic liquid 1-ethyl-3-methylimidazolium bis (trifluoromethyl-sulfonyl) amide (EMIM BTA), since this solubility of air under pressure is minimal and the condensation easily sorted out.

As in the in Fig. 3A shown topology (false two-stage without intermediate pressure chamber) the high pressure spaces 53a, 53b always remain under pressure (at low pressure compression or relaxation between 1 bar and the volume ratio of low pressure chamber 59a, 59b to high-pressure chamber 53a, 53b, with high pressure compression or relaxation between this same ratio and the accumulator pressure ) is the circulation by means of switch valve practically unavoidable (except for the solution with two hydrostatic units), otherwise a trapped volume would oscillate back and forth without venting and cleaning and with a heat exchange only through the wall of high pressure pipes, which is a disadvantage multi-stage teiladiabatischen compressors is.

The pseudo-two-stage arrangement chosen here considerably simplifies the valve technology, since only the high-pressure valves 66a, 66b have to be activated in motor operation as a function of a plurality of operating parameters, whereas the circuit of the low-pressure valves 56a, 56b is synchronized with the respective suction valve via the control pistons 54a, 54b. / Exhaust valve 86a, 86b is introduced via its control piston by reversing the direction of the measuring piston 72a, 72b or the reversal of the flow of a hydrostatic unit 87 at the dead centers. With this arrangement, it is therefore possible to cope with the highest pressures with only two "false" stages (or with a small precursor of 5 to 6 bar and the main stage of 200 to 300 bar, with the respective laminated core 53a, 53b always in connection with both working spaces remains), which means a significant improvement in efficiency compared to the usual 4- or 5-piston machines.

The hydrostatic unit 87 is controlled by a control unit 88, which in turn is controlled by running on a processor or other processing unit software.

The high pressure valve flaps 65a, 65b perform a complex task, especially in the case of engine operation, because here the switching point is not tied to the dead centers and must be determined in the motor case by means of computers and sensors. Indeed, working with a liquid piston allows fixing the upper delivery dead point of the respective volumetric flask 72a, 72b over the valve seat plane, the liquid will only bypass the high pressure valve flap 65a, 65b and partially fill the cavity 67a, 67b. In order for the liquid to drain again after the dead point, the closure of the respective high-pressure valve flap 65a, 65b must be delayed such that the liquid piston mirror 70a, 70b passes the seating plane at the moment when the high-pressure valve flap 65a, 65b hits its seat. Thus, a dead volume free compressor operation is guaranteed, which is technically relatively easy to implement by the high pressure valve flaps 65a, 65b made floatable, which automatically causes the desired delay. The situation is different in the engine operation, because here after the opening of the respective high-pressure valve flap 65a, 65b, which is initiated by the staggered Flüssigkolbentotpunkt by raising the passage remain free for a while after the liquid piston mirror 70a, 70b has passed the seating plane (displacement volume -Feed). This is achieved by the steel disc attached to the back of the respective high-pressure valve flap 65a, 65b, which bears against the magnet after opening, and the adhesive force holding the high-pressure valve flap 65a, 65b in the open position, as long as a current flows through the connecting wires of the magnetizing magnet coil 68a, 68b flows. The Control of the magnetic retaining coils 68a, 68b is performed by a control unit, such as the processor.

Probably other types of actuation are conceivable at this point, but the way over the holding magnet additionally allows the exact detection of the opening time thanks to the change in the coil current at the moment of impact of the steel disc on the respective magnetic retaining coil 68a, 68b, as a signal for the purpose of accurate determination of the active liquid excess and can serve appropriate control, through the measurement of the time between stop and dead center. In addition, this solution is energetically extremely economical despite rapid valve closing. These advantages are, however, due to the need to perform a few compressor strokes at startup before initiating engine operation.

While in Fig. 3A is shown as in the compression of the gas, a high pressure in the high-pressure chamber 52b is generated, is in Fig. 3B the high-pressure compression of the gas in the high-pressure chamber 52a is shown (the storage space in which the compressed gas is stored is in the Fig. 3A to 3D for the sake of clarity, however, the connections for the storage space at the high-pressure valves 66a, 66b are shown). While in Fig. 3B shown operating phase, the control piston 54a, 54b are driven such that the low pressure valve 56a is closed, ie, the laminated core 53a is in the upper position, and the low pressure valve 56b is opened, ie, the laminated core 53b is in the lower position. The liquid located in the right chamber of the volumetric flask 72a is pumped by the hydrostatic unit 87 via the check valve 82a into the high-pressure space 52a, whereby a high pressure is generated there. At the same time, the liquid in the high-pressure chamber 52b is transferred via the 7/2 way switch valve 76b and the check valve 81b promoted in the left chamber of the volumetric flask 72b.

At the in Fig. 3B shown working phase, the suction / exhaust valve 86a is opened so that a pressure equalization can take place in the pre-pressure space 59a with the environment. At the same time, the suction / exhaust valve 86b is closed to produce the required pre-pressure in the pre-compression space 59b.

The liquid contained in the exchange volume 80 a is in Fig. 3B circulated by the pump 85. In this case, for example, the exchange volume 80a is emptied into the reservoir 78 and new liquid pumped from the reservoir 78 in the exchange volume 80a.

The Fig. 3C and 3D show the two phases of work in the relaxation of the gas, ie the engine operation, in which the energy stored in the compressed gas from the hydrostatic unit 87 or units connected thereto in other forms of energy, eg. As electrical energy or mechanical work is converted.

Fig. 3C shows a working phase in which the low pressure valve 56a is opened and the low pressure valve 56b is closed. Further, the suction / exhaust valves 86a, 86b are closed and opened, respectively. About the open high-pressure valve 66b of the first filled with the liquid high-pressure chamber 52b is acted upon by the pressure present in the storage space. As a result, liquid is passed from the high-pressure chamber 52b via the 7/2-way switch valve 76b, the exchange volume 80b and the check valve 81b into the left-hand chamber of the volumetric flask 72b. The volumetric flask 72b thus moves to the right and drives the hydrostatic unit 87.

By coupling the volumetric flask 72a to the volumetric flask 72b, the liquid from the right chamber of the volumetric flask 72a is pumped via the 7/2-way diverter valve 76a and the check valve 82a into the high-pressure chamber 52a, in which via the opened low-pressure valve 56a by means of is also generated at the volumetric flask 72b coupled form piston 60 of the form.

The liquid contained in the exchange volume 80 a is in Fig. 3C circulated by the pump 85.

In Fig. 3D the second working phase is shown in the engine operation. Here, the low-pressure valve 56a is closed, and the low-pressure valve 56b is opened. Further, the suction / exhaust valves 86a, 86b are opened and closed, respectively. About the open high-pressure valve 66a of the first filled with liquid high-pressure chamber 52a is acted upon by the pressure present in the storage space. As a result, liquid from the high-pressure chamber 52 a via the 7/2-way switch valve 76 a, the exchange volume 80 a and the check valve 81 a is pressed into the right chamber of the volumetric flask 72 a. The volumetric flask 72 a thus moves to the left and drives the hydrostatic unit 87.

By coupling the volumetric flask 72b to the volumetric flask 72a, the liquid from the left chamber of the volumetric flask 72b is pumped via the check valve 82b into the high-pressure chamber 52b, in which the pre-pressure is generated via the opened low-pressure valve 56b by means of the pre-pressure piston 60 likewise coupled to the volumetric flask 72a becomes.

The liquid contained in the exchange volume 80b is in Fig. 3D circulated by the pump 85.

Subsequently, the cycle, as in the Fig. 3C and 3D shown, repeated.

The simplicity of in Fig.1 The basic circuit shown is at the expense of the complexity of detecting the Hubverlaufs and the additional use of a hydrostatic unit including low pressure generator and expander, which can bring disadvantages in terms of price and efficiency, although larger plants, which are composed of many high-pressure liquid piston chambers in parallel strands, a single form pressure apparatus can serve all strands. In that sense, that is in Fig. 3A shown push-pull element with a simple volumetric flask more suitable for small systems, since only two liquid points, two volumetric flasks with intermediate intermediate pressure piston and a circulation pump must be added to the two liquid piston to form an autonomous push-pull element which is doubled to a pulsation composite unit.

Although at least for compression purposes, the use of a single piston assembly according to Fig. 1 can be useful, it is recommended for motor purposes (relaxation operation), a liquid piston assembly with four liquid pistons, as shown schematically in Fig. 5 is shown. The four pistons enable a compact speed controllable unit with low torque pulsations, whose characteristics are reflected in the Fig. 6 disclose diagram shown.

The liquid piston arrangement comprises two push-pull elements 101 and 101 'with volumetric flasks 102a, 102b, 102a', 102b ', which are hydraulically connected to a common shaft 115 via a cross-section, each with a variable hydrostatic unit 103, 103'. Each of the push-pull elements 101, 101 ' contains two liquid pistons, which are operated in push-pull mode. The push-pull elements 101, 101 'generate by feedback of the Schluckvolumenverstellungen 104, 104'zum Kolbenkolbenhub a in Fig. 6 shown displacement volume curve Q _(V1) + Q _(V2) , which corresponds to a slightly modified sine curve. The two displacement volumes Q _(V1) and Q _(V2) are shifted by half a stroke in push-pull against each other. By applying pressure p _{(V) of} the absorption volume, the individual torque of the respective unit M _(V1) , M _(V2) arises mutatis mutandis and by the sum of the shifted individual torques of the torque curve M. Thus, we see that through the displacement volume curve Q _(V) Hyperflex pressure tip "filter out" leaves, which is a well-known obstacle in compressed air drives.

Fig. 5 also shows the versatility of the switch valve concept with the arrangement of a single processing unit 105 in connection with the respective switch valve housings 106, 106 'and the exchange containers 107, 107' on the four liquid piston housings 108a, 108b, 108a ', 108b'.

The liquid piston assembly is also suitable, purely mechanical links speed adjustment with "impressed pressure" (this is called the speed control from the pressure source, the torque against the load determines the speed) in engine operation, with the help of steam engine linkage: the Suction volume curve Q _{(V) of} the Fig. 6 is determined by scanning a cam profile 110, which is transmitted by the movement of the piston rod 111 to the rocker 112, wherein the amplitude of the transmission to the displacement volume adjustment 104 by the height adjustment of the sliding engagement of the rod 113 by means of screw handwheel 114 results. The curve Q _(V) can thus be modulated up to the reversal of the direction of rotation as soon as the height adjustment reaches beyond the pivot point of the rocker 112.

Fig. 7A schematically shows a liquid piston assembly 150 with a simplified switch valve concept. The liquid piston assembly 150 is equipped with only one switch valve 151, which controls two measuring piston 152 a, 152 b of this push-pull element in response to the pressure difference across the hydrostatic unit 153, which occurs between the lines 154 a, 154 b and the switch valve 151 acts.

The further elements of this simplified volumetric piston push-pull element are two liquid pistons 165a, 165b with valves and control piston and a storage space 166. Connecting lines 167a, 167b lead from the liquid pistons 165a, 165b to the storage space 166. A liquid tank 168 is provided as a maintenance unit with filter and heat exchanger , where no circulation pump is required here. A computer actuator 169 moves the displacement volume adjustment of the hydrostatic unit 153 in response to the feedback 170 of the piston position and the setpoint input 171, wherein the possibility of a direct coupling of Vordruckkolben 172 a, 172 b is indicated by dashed lines.

Various operating states of the liquid piston assembly 150 are shown in FIGS Figs. 7A to 7D shown, wherein the Figs. 7A and 7B the compression of the gas with the expenditure of energy and the Figs. 7C and 7D show the relaxation of the gas.

At the in Fig. 7A shown first position of the switch valve 151, the hydrostatic unit 153 pumps liquid into the left chamber of the measuring piston 152 a. The right chamber of the volumetric flask 152a is in the Liquid tank 168 emptied. Further, the liquid is pumped from the right chamber of the measuring piston 152b into the liquid piston 165a. The liquid piston 165b is drained. In this case, the air in the liquid piston 165a is compressed until the pressure is high enough that the high-pressure valve of the liquid piston 165a opens.

In Fig. 7B the second position of the switch valve 151 is shown. Here, the hydrostatic unit 153 pumps liquid into the right chamber of the measuring piston 152b, and the left chamber of the measuring piston 152b is discharged into the liquid tank 168. The volumetric flask 152a pumps liquid into the liquid piston 165b while the liquid piston 165a is being emptied. Thereby, the pressure in the storage space 166 is increased via the liquid piston 165b.

In motor operation, ie the relaxation of the gas contained in the storage space 166, is in the in Fig. 7C shown position of the switch valve 151 liquid from the liquid piston 165 b pumped by the pressure of the gas from the storage space 166 in the left chamber of the measuring piston 152 a. The liquid from the right chamber of the volumetric flask 152a is pumped into the liquid piston 165a. Since the two volumetric flasks 152a and 152b are coupled together, the volumetric flask 152b drives, via its right-hand chamber, the hydrostatic unit 153 and the shaft connected thereto.

At the in Fig. 7D shown position of the switch valve 151, the functionalities are reversed. The liquid piston 165a transfers the high pressure from the storage space 166 to the measuring piston 152b, whereby the measuring piston 152a drives the hydrostatic unit 153, which converts the energy into a movement of the shaft.

In the present description, all wave / liquid transducers with good reason as a reversible hydrostatic 4-quadrant units are shown, because thus the stroke can be given low loss. This does not exclude other drive solutions, however, the known solutions are problematic. Thus, for example, fails the mechanical arrangement with connecting rod and piston - although with reasonably useful curve with deceleration at the stroke ends - on the bearing forces that occur at higher power and low speeds, apart from the required reduction gears.

Furthermore, the exchanger piston working space in the Fig. 1 to 7 shown only as a tilted rectangular prism for receiving the laminated core, with the high pressure valve at the top tip. Again, other solutions are conceivable, for. B. as a metal roll as described below. However, the funneling action of the tilted rectangular prism has the most favorable behavior with respect to the stability of the liquid level during fast movements, so that this structure would probably even be suitable for spray-exchange.

Fig. 8 schematically shows a part of a liquid piston assembly 180 with a (heat) exchanger roller 181 as an alternative to the rectangular prism. The exchanger roller 181 consists of a rolled-up piece of sheet metal. The (heat) exchanger roller 181 is embedded in the cylinder body 182, the oblique parting line 183 with the piston block 184 produces a convergence to the high pressure valve 185 out, similar to the prismatic laminated core 53 a, 53 b of Fig. 3A , The (heat) exchanger roller 181 is wound around a cylinder body 186 of the piston block 184. The (heat) exchanger roller 181, together with the cylinder body 186, is penetrated laterally from the bottom upwards by a pin-shaped seat valve body 187, so that via a cone 188 the connection between admission pressure chamber 189 and the liquid piston space in the (heat) exchange roller 181 can be switched.

By means of the (heat) exchanger roller 181 a dead volume-free circuit without movement of the sheet metal exchanger is possible. Instead of the sheet metal exchanger, the cone 188 is moved here in order to open or close the connection between the admission pressure chamber 189 and the liquid piston space in the (heat) exchange roller 181. The movement of the cone 188 is effected by acting on a control piston 190 via a connection nipple 191, whereby a retaining spring 192 is compressed.

Otherwise are in Fig. 8 they are already out Fig. 3A provided known elements, such as suction / exhaust valve, volumetric flasks, Vordruckkolben, hydraulic switch, etc., which ensure friction-free operation. The roller part including control valves can of course be operated without a volumetric flask, in the sense of Fig. 1 with separate low-pressure generator or expander. In the Fig. 8 shown exchanger roller 181 including control valves can also in the in the Fig. 1 . 3 . 5 and 7 inserted liquid piston assemblies are inserted.

Finally, it should be emphasized that around the isothermal liquid piston - whether with plates or spray - a complex environment with frictionless interacting organs is required, which are intimately interlocked in the function.

In summary, it can be said that the indirect exchanger made of sheet metal plates with fine and fixed distances between the plates is inserted in push-pull circuits with adjustable hydrostatic units for the purpose of low-loss kinematic connection with a fast-rotating shaft. It is on the rigorous cyclical Pay attention to the replacement of the liquid, so that an optimal heat dissipation with continuous treatment (degassing, decantation, water separation) in a pressureless sump container is possible. There are various types of push-pull elements possible (with two hydrostatic units and foreign form pressure, with switch valves and volumetric flasks to take a pilot piston, with a single central switch valve for both volumetric flasks and mixtures of these variants), with a combination of two phase-shifted push-pull elements a pulsationsarmes device possible makes, as a flywheel-type air / wave transformer with variable speed together with a high-pressure air tank is a flexible energy storage, which has the advantage over electrochemical batteries to drive directly from shaft machines or vehicles can.

Claims (1)

1. A liquid piston arrangement (180) for compressing and expanding gases, comprising

   - a liquid piston which is embodied by a liquid level formed by a liquid in a high-pressure space;

   characterized by

   - a coil (181) which is supported in the high-pressure space as a heat exchanger and is sequentially flowed around by the liquid;

   - a low-pressure valve cone (188) for connecting the high-pressure space to a low-pressure space (189); and

   - a control (187) of the low-pressure valve cone (188) which extends through the high-pressure space.

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