Arrangement and method for converting thermal energy

Abstract

Arrangement for converting thermal energy into mechanical energy, comprising at least a first and at least one second heat reservoir, wherein the temperature of the first heat reservoir (WR) is higher than that of the second heat reservoir (KR), a liquid heat transfer medium, a first double cylinder pair consisting of a first double cylinder with a first double piston (Z113) and a second double cylinder with a second double piston (Z123), wherein each double piston (Z113, Z123) divides the associated double cylinder into a working chamber (Z111, Z121) and a pumping chamber (Z112, Z122), wherein an expansion of the working chamber (Z111, Z121) causes a compression of the pumping chamber (Z112, Z122), at least one heat exchanger (W1), pipes connecting the double cylinders to the heat exchanger (W1) and the first and second heat reservoirs (WR, KR), and valves, characterized in that o the first and second double pistons (Z113, Z123) are mechanically coupled such that an expansion of the working chamber (Z111) of the first double cylinder (Z11) causes a compression of the working chamber (Z121) of the second double cylinder (Z12) and a compression of the working chamber (Z111) of the first double cylinder (Z11) causes an expansion of the working chamber (Z121) of the second double cylinder (Z12), ◯ the heat exchanger (W1) is designed such that heated heat transfer medium enters at an inlet W11E) of the first side (W11) of the heat exchanger (W1) and exits as cooled heat transfer medium at an outlet (W11A) of the first side (W11) of the heat exchanger (W1), and cooled heat transfer medium enters at an inlet (W12E) of the second side (W12) of the heat exchanger (W1) and exits as heated heat transfer medium at an outlet (W12A) of the second side (W12) of the heat exchanger (W1), wherein during the heat transfer from the first side (W11) to the second side (W12) of the heat exchanger (W1), the heat transfer medium on the first side (W11) contracts thermally and expands thermally on the second side (W12), wherein no phase transitions of the liquid heat transfer medium occur, o the heat transfer medium exhibits a thermal expansion that is greater than the volume by which the heat transfer medium is reduced compared to its uncompressed volume due to compressibility when the pressure increases, o the valves and pipes are arranged and configured such that they supply heated heat transfer medium from the outlet (W12A) of a second side (W12) of the heat exchanger (W1) to the working chamber of the first double cylinder, so that an expansion of the working chamber (Z111) of the first double cylinder (Z11) and a compression of the working chamber (Z121) of the second double cylinder (Z12) of the first double cylinder pair as well as a compression of the pumping chamber (Z112) of the first double cylinder (Z11) and an expansion of the pumping chamber (Z122) of the second double cylinder (Z12) take place, o when a reversal point of the double piston (Z113) of the first double cylinder (Z11) is reached, the functions of the first and second double cylinders (Z11, Z12) are reversed.

Description

[0001] The present invention relates to an arrangement and a method for using the temperature difference between two heat reservoirs to perform mechanical work or generate electrical energy. This is achieved by exploiting the thermal expansion of a heat transfer medium.

[0002] A number of proposals are known from the state of the art to use the thermal expansion of fluids to generate mechanical work.

[0003] The arrangement according to JP S58-158 379 A proposes the use of a single double cylinder. A first chamber of the double cylinder acts as a pumping chamber, while the second chamber functions as a working chamber. Cooling of a fluid takes place in a low-pressure tank, and heating and thermal expansion of a fluid takes place in a high-pressure tank. A flywheel stores energy to start the machine. During start-up, fluid is sucked from the low-pressure tank through the pumping chamber and forced from the working chamber into a heat exchanger and from there into the low-pressure tank. When the lower reversal point of the piston in the working chamber is reached, the fluid flow is reversed via valves. The working chamber expands and takes in fluid from the high-pressure tank. At the same time, the pumping chamber compresses and presses fluid through the heat exchanger into the high-pressure tank.In order for this mechanism to function continuously, the document states that the amount of fluid pumped out of the pumping chamber and the amount of fluid pumped through the working chamber must be the same.

[0004] US 4,637,211 describes an apparatus and method for converting thermal energy into mechanical energy using a heat engine with a liquid working fluid that remains in a closed fluid system throughout the entire cycle and does not undergo a phase change. The closed fluid system for the liquid working fluid comprises a pair of double cylinders arranged side by side and operating in push-pull mode. High-pressure working fluid from a heat exchanger containing one or more thin heat transfer plates is alternately fed to the working chambers by actuating control valves, while low-pressure working fluid from the pumping chambers is moved into the heat exchanger. A hot and a cold heat reservoir are provided to maintain the working fluid at the appropriate temperature.

[0005] The engine for converting thermal energy into stored fluid energy according to US 7 000 389 B2 comprises expansion cylinders with expansion chambers and elastic membranes or double cylinders. Heating and cooling of a working fluid in the cylinders takes place via supply lines connected to external heat sources and sinks. A pressure accumulator is suitable for storing a pressurized fluid, such as hydraulic oil, from the individual cylinders and releasing it at an increased pressure above a minimum pressure level, regardless of the irregularities in the movement of the expansion cylinders. In one embodiment, the cylinders are designed as coupled (working) double cylinders with attached single-acting pump cylinders. The double pistons of the two double cylinders and pump cylinder are moved in counter-phase via a rocking mechanism.The preferred working medium is a liquid with a high thermal expansion coefficient.

[0006] DE 10 2012 010 909 A1 describes a machine for thermomechanical energy conversion. This is made possible by two closed cycles, each using a different refrigerant. Gaseous refrigerant is cooled, liquefied, and mechanical work is performed through the resulting pressure and volume difference. There is a primary circuit and a secondary circuit. The primary circuit is operated with CO2, the secondary circuit with ammonia (NH3).

[0007] The subject of DE 10 2021 003 419 B3 is a CO2 engine with a system in which at least one gas cylinder with a large piston volume is directly connected to a liquid gas cylinder with a small piston volume. These cylinders move back and forth synchronously with each other and can change their volume during operation. In a primary circuit, warm CO2 gas from the gas cylinder transfers its energy in a multifunctional countercurrent heat exchanger to the cold, liquid, and evaporating CO2 in a cold secondary circuit. The CO2 liquefies, and the cold, liquid CO2 from the secondary circuit is heated and evaporates.

[0008] DE 11 2008 001 613 T5 discloses an energy transfer machine having passages forming a closed circuit and containing a compressible fluid that is at least partially compressed above atmospheric pressure and during normal operation. The compressible fluid has a constant phase in the closed circuit. A coupled pressure-shift transition point is present at the closed circuit and divides the closed circuit into a first energy transfer circuit and a second energy transfer circuit. During operation, the first energy transfer circuit and the second energy transfer circuit have different pressures, with one having a higher pressure than the other. Depending on the operating time, this pressure difference can also be reversed.First flow control devices on the first energy transfer circuit are coordinated to permit pulsed flow through the first energy transfer circuit with energy transfer through the coupled pressure displacement interface.

[0009] Second flow control devices on the second energy transfer circuit are coordinated to allow pulsed flow through the second energy transfer circuit, with energy transfer through the coupled pressure-displacement interface. The first flow control devices and the second flow control devices are coordinated to allow the pulsed flows in the first energy transfer circuit and the second energy transfer circuit to combine to create a flow around the closed circuit. An input-output device is connected to the coupled pressure-displacement interface for inputting energy into or extracting energy from the coupled pressure-displacement interface.

[0010] The engine according to US 2015 / 0 285 183 A1 has a first and a second cylinder chamber. The first chamber receives gas through a first inlet valve. The gas is compressed by a piston in the cylinder and leaves the first chamber through a first exhaust valve. The second chamber is supplied with gas through a second inlet valve and compressed from the first chamber through a second inlet valve. The gas expands in the second chamber while exerting work on the piston before leaving the second chamber through a second exhaust valve. The engine is controlled so that gas flows from the first chamber into the second chamber as the engine performs a working cycle, and the engine is further controlled so that a piston compresses gas, which exerts work on the same piston, which is connected to a crank mechanism by a rod. The work is transferred from the rod by essentially only rectilinear motion.

[0011] The subject of DE 20 2022 104 753 U1 is a temperature difference engine. The engine has two tanks, each directly connected to a cylinder with a piston. Heat exchangers are located in the tanks. Volume expansions in the tank thus directly affect the pistons, which drive a generator in opposite directions via crankshafts. The tanks are filled with gas. The heat exchangers are alternately pressurized with cold and warm medium, which leads to expansion and cooling of the gas, respectively. The alternating pressurization is valve-controlled. There is no phase change of the gas.

[0012] Although the use of thermal expansion of fluids has been proposed in several publications, it has not yet been comprehensively implemented. Reasons for this may include unsuitable system design, which, for example, prevents continuous operation, or the large forces or pressures that must be controlled.

[0013] There is therefore still a need to propose an arrangement or a procedure that realizes the extraction of mechanical work from temperature differences by utilizing the thermal expansion of working fluids, in particular liquids.

[0014] According to the invention, the object is achieved by an arrangement according to claim 1. An advantageous method for operating the arrangement is disclosed in claims 14 and 15. Advantageous embodiments of the arrangement and the methods can be found in the dependent subclaims.

[0015] The arrangement according to the invention for converting thermal energy into mechanical energy has at least a first and at least one second heat reservoir, wherein the temperature of the first heat reservoir is higher than that of the second heat reservoir. The arrangement further comprises a liquid heat transfer medium and a first double cylinder pair. The first double cylinder pair has a first double cylinder with a first double piston and a second double cylinder with a second double piston. Each double piston divides the associated double cylinder into a working chamber and a pumping chamber, wherein an expansion of the working chamber causes a compression of the pumping chamber. The piston rods are preferably arranged in the pumping chambers. The arrangement according to the invention further comprises at least one heat exchanger, pipes connecting the double cylinders to the heat exchanger and the first and second heat reservoirs, and valves.Characteristic of the arrangement according to the invention is that. ◯ the first and second double pistons are mechanically coupled in such a way that an expansion of the working chamber of the first double cylinder causes a compression of the working chamber of the second double cylinder and a compression of the working chamber of the first double cylinder causes an expansion of the working chamber of the second double cylinder, ◯ the heat exchanger is designed so that heated heat transfer medium enters at an inlet on the first side of the heat exchanger and exits as cooled heat transfer medium at an outlet on the first side of the heat exchanger and cooled heat transfer medium enters at an inlet on the second side of the heat exchanger and exits as heated heat transfer medium at an outlet on the second side of the heat exchanger, wherein during the heat transfer from the first side to the second side of the heat exchanger, the heat transfer medium on the first side contracts thermally and expands thermally on the second side, wherein no phase transitions occur, ◯ the valves and pipes are arranged and configured in such a way that they supply heated heat transfer medium from the outlet of a second side of the heat exchanger to the working chamber of the first double cylinder, so that an expansion of the working chamber of the first double cylinder and a compression of the working chamber of the second double cylinder as well as a compression of the pumping chamber of the first double cylinder and an expansion of the pumping chamber of the second double cylinder take place, ◯ when the double piston of the first double cylinder reaches a reversal point, the functions of the first and second double cylinders are reversed.

[0016] The basic operating principle of the arrangement is that heat transfer medium flows alternately into the working chambers of a pair of double cylinders at very high pressure due to thermal expansion, where it performs mechanical work by expanding and thus acting on the piston surface of the double piston. The heat transfer medium on the second side of the heat exchanger absorbs heat from the first side of the heat exchanger. This causes thermal expansion of the heat transfer medium. The heat transfer medium remains liquid throughout the entire process. A phase transition (neither first nor higher order) therefore does not occur. Using a suitably arranged check valve, the thermal expansion can be controlled so that it only takes effect via the outlet of the second side of the heat exchanger in the direction of the working chamber of the first double cylinder, where it causes expansion and thus displacement of the double piston.The movement of the double piston compresses the pumping chamber, forcing the heat transfer medium located there into the inlet on the second side of the heat exchanger. By means of a rigid or articulated / elastic coupling of the double pistons of the first and second double cylinders, the movement of the double piston of the first double cylinder can be transferred to that of the second double cylinder. Since the arrangement of the chambers of the first and second double cylinders is mirror-symmetrical, the transferred movement causes the pumping chamber of the second double cylinder to expand, drawing in cool heat transfer medium from the second heat reservoir. The working chamber of the second double cylinder is compressed and releases the heat transfer medium towards the first heat reservoir. The heat transfer medium absorbs heat in the first heat reservoir and moves from there to the inlet on the first side of the heat exchanger.In the heat exchanger, the heat transfer medium gives off heat to the second side of the heat exchanger, contracts thermally in the process and is conducted from the outlet of the first side of the heat exchanger to the second heat reservoir. When the expansion of the working chamber of the first double cylinder reaches its maximum value, further expansion is not possible. This marks the reversal point of the movement of the double piston of the first and, due to the rigid coupling, also of the second double cylinder. The reversal point is the point in the movement of the double piston at which the direction of movement of the double piston reverses (i.e. from expansion to compression or from compression to expansion). Since a double piston simultaneously brings the associated pumping chamber to the same pressure when the working chamber expands, extremely large forces act within the double piston that cannot be transmitted via elements such as a push rod or connecting rod.Only the effective forces then act outwards via the push rod on a crank system. This arrangement is what makes it possible to handle such high pressures. Through suitable valve control, the flow of the expanding heat transfer medium is no longer directed into the working chamber of the first double cylinder, but rather into the working chamber of the second double cylinder. This means that the previously first double cylinder now becomes the second double cylinder and vice versa. The previously first working chamber now becomes the second working chamber and the previously second working chamber now becomes the first working chamber. The first and second double cylinders thus exchange their functions and the process continues as described above within the framework of another cycle.When the double piston of the second double cylinder reaches its reversal point, the valve control switches the flow of the heat transfer medium back to its original configuration. A characteristic of the arrangement's operation is that it operates exclusively with a heat transfer medium that does not undergo any phase change, particularly no change in state of aggregation, throughout the entire process. The heat transfer medium exhibits a thermal expansion that is greater than the volume by which the heat transfer medium is reduced compared to its uncompressed volume due to its compressibility when pressure increases.

[0017] Since two counter-rotating working chambers are provided in each of the double cylinder pairs, after the expansion of one working chamber, the work performed and movement of the double piston in the other working chamber causes the heat transfer medium to flow out of the other working chamber. From there, the heat transfer medium flows into the first heat reservoir, designed as a warm reservoir, and from there into the first side of the heat exchanger, where it releases heat. It then flows into a second heat reservoir, designed as a cold reservoir. The pump chambers of the double cylinders on the respective opposite sides of the double piston draw in cool heat transfer medium with a lower specific volume from the cold reservoir during expansion and then pump it into the second side of the heat exchanger during contraction, where the heat transfer medium is heated and expanded for use in the working chambers, thus closing the cycle.In this respect, the arrangement consists of a single fluid circuit.

[0018] In one embodiment, one or more pressure accumulators are arranged in pipes from the outlet of the second side of the heat exchanger to the inlet into the working chamber and / or in pipes from the pumping chamber to the inlet of the second side of the heat exchanger, which buffer pressure fluctuations.

[0019] Preventing backflow through check valves and controlling heat transfer fluid flows according to specified starting and ending points using appropriate valve circuits and piping are familiar to those skilled in the art. The design of the necessary piping is also known according to the state of the art. Furthermore, the individual valves and piping may vary depending on the individual embodiments explained below. They are therefore not described separately. As a rule of thumb, all piping should preferably carry flow in only one direction. Appropriate check valves ensure this if necessary.

[0020] In one embodiment of the arrangement, the double pistons are designed as plungers. A plunger is a piston-shaped unit sealed by one or more fixed seals acting on the outside of the plunger. Conventional pistons, in contrast, have seals that are moved along with the piston movement. A plunger displaces the working medium independently of direction. A piston, in contrast, displaces mass vectorially. In one embodiment, the one or more seals of the plunger are made of Teflon, silicone, PU, ​​or a similar material with low friction and high compressive strength.

[0021] The mechanical coupling of the plungers of a double-cylinder pair is preferably achieved by means of a connecting rod that rigidly connects the two plungers of the pumping chambers of a double-cylinder pair. This rigid mechanical connection advantageously ensures precisely coordinated movement of the plungers of the two double cylinders of a double-cylinder pair. This eliminates any adverse switching times or inertia. This precise coordination cannot be achieved using valve control alone.

[0022] Since the heat transfer medium in the working chamber and the pumping chamber is at different temperatures, an adverse heat flow between the chambers could occur through the plungers. Therefore, one embodiment provides at least one, optionally several thermal insulation layers to reduce the heat flow between the working chamber and the pumping chamber. The at least one thermal insulation layer is aligned within the plungers, perpendicular to the movement of the plungers, thus inhibiting the heat flow from the working chamber to the pumping chamber. To reduce further heat loss, the double cylinders and / or double pistons optionally have thermal insulation, at least in the area of ​​the working chamber. In particular, a thermal insulation layer can be arranged between the double cylinders. In addition, an outward-facing thermal insulation layer can surround the two double cylinders.

[0023] In one embodiment of the arrangement, the volume of the pumping chamber is reduced by the value compared to the volume of the working chamber, which corresponds to the volume expansion of the heat transfer medium in the heat exchanger (application example: ≈7% at 400 bar and ΔT = 66K in the heat exchanger).

[0024] The pumping chamber and the working chamber of a double cylinder can be arranged in a housing of the double cylinder. The double piston is moved back and forth within the pumping chamber as well as within the working chamber. The double cylinders can be designed as differential cylinders. The piston areas can be of different sizes or the same size. Under certain circumstances, it can be advantageous for the piston areas to be the same size or approximately the same size. It can be provided that the piston area in the working chamber of a double cylinder and the piston area in the pumping chamber of this double cylinder are of the same size. The working chamber and the pumping chamber of a double cylinder can have a common, reciprocating compression factor, which is preferably 1 and / or which is selected in particular depending on the working medium used.

[0025] The extraction of mechanical energy from the arrangement preferably occurs at the mechanical coupling of the first and second double pistons or at one or both piston parts of a double piston in the working chamber(s) of a double cylinder pair. In one embodiment, a push rod is arranged on one or both piston parts in the working chamber(s), which takes the piston movement from the double cylinder and supplies it, for example, to a connecting rod drive. A relatively low cycle rate (on the order of 1 expansion cycle per second) is preferred for the arrangement according to the invention, with very large forces provided via the push rod(s) from the double cylinders. However, to achieve effective conversion into other forms of energy, a higher cycle rate or speed is often necessary for generators. Therefore, a corresponding transmission ratio of the push rod movement is necessary.Gearbox solutions similar to those used in wind turbines can be advantageously used for this purpose. There, too, low speeds with large acting forces are translated into higher speeds with lower forces. Planetary gears are one example. To avoid torques on a crankshaft, a coaxial decoupling is advantageous. In this case, the two double cylinder pairs are positioned opposite each other, the decoupling occurs via a push rod on the front side of the working chamber, and the double piston pairs are arranged in a line. In this configuration, the push rods work against each other, and any torques occurring on the crankshaft cancel each other out.

[0026] In another embodiment, energy is generated directly from the movement of the rigid mechanical coupling of the double pistons or a push rod by means of at least one linear generator. In principle, AC generators, DC generators, or linear generators are possible for generating electrical energy.

[0027] In one embodiment, the valves are controlled by means connected to the push rod(s). This can be implemented mechanically, electromechanically, or electronically. For example, appropriate toothing can be attached to the mechanical coupling or to the push rods emerging from the working chambers, which is used to control the valves. Appropriate stop switches or similar devices are also possible for detecting the reversal points of the double-piston movements. These switches actuate the valves via an electrical control system and, for example, switch the flow of the heat transfer medium from the working chamber of the first double cylinder to that of the second double cylinder. Control is also possible with the aid of an electronic data processing system. For this purpose, the device has sensors at the necessary measuring points.The placement of sensors and other devices (valves, slides, other actuators, etc.) depends not only on the control tasks and the specific circuitry of the device when using an electronic data processing device, but in most applications, and can be adapted to the requirements by a specialist.

[0028] In one embodiment, a second or further double cylinder pairs, in particular two, three, four, five or six double cylinder pairs, are present in the arrangement. The piston positions of these double cylinder pairs differ from those of the first double cylinder pair, i.e. their piston positions are phase-shifted compared to that of the first double cylinder pair. Several double cylinder pairs preferably act on a common power transmission device, e.g. a crankshaft or a gearbox. As a result, the phase shift between the double pistons of different double cylinder pairs is fixed and remains unchanged even during operation. The phase shift supports problem-free start-up of the arrangement, even when the double pistons of a double cylinder pair are at a reversal point.To ensure this, the phase shift when a second double cylinder pair is present differs from 0° to 180°, preferably 90°, relative to the first double cylinder pair. If more than two double cylinder pairs are present, the phase shift between the double cylinder pairs is preferably determined by the relationship 360° / (number of all double cylinder pairs).

[0029] The heat transfer medium used is a liquid whose thermal expansion exceeds its compressibility. Alcohols, preferably ethanol (n-ethanols), have proven suitable. The heat transfer medium is subjected to a maximum pressure of between 200 bar and 8000 bar in the heat exchanger. Due to thermodynamic laws, the energy yield is higher at high pressure than at low pressure.

[0030] As with all processes that utilize a temperature difference to generate energy, the energy yield in the present invention also increases with the temperature difference. Since the system is particularly suitable for generating energy from low-temperature sources, the temperature difference between the first and second heat reservoirs should be at least 20 K, preferably 40 K, and particularly preferably 50 to 80 K.

[0031] As the first heat reservoir, a heat exchanger (not identical to the heat exchanger) is preferably used, in which the heat transfer medium is charged (heated) by means of heat from a technical or natural source, in particular waste heat from an industrial process, heat from a geothermal storage facility, geothermal heat, solar thermal energy or heat from a heat pump process.

[0032] The second heat reservoir is preferably designed so that the heat transfer medium is discharged (cooled) via a further heat exchanger (not identical to the heat exchanger) in the direction of a geothermal storage facility, another heat storage facility, into the environment or to a heat pump.

[0033] The heat exchangers of the first and second heat reservoirs are also designed as heat exchangers, but are referred to as heat exchangers for reasons of differentiation.

[0034] Charging refers to the addition of heat to the heat transfer medium. Discharging, accordingly, refers to the removal of heat from the heat transfer medium.

[0035] In principle, any heat source with sufficient capacity and within a suitable temperature range is suitable as a heat source for the first heat reservoir. The same applies to the heat sinks, whereby at least the above-mentioned temperature differences between the first and second heat reservoirs should be achieved. Temperatures of approximately 60°C to 120°C have proven particularly suitable for the first heat reservoir, and temperatures above -25°C to 40°C for the second heat reservoir. As already mentioned, large temperature differences improve the effectiveness of the arrangement. In principle, the arrangement is also possible in other temperature ranges, down to the negative Celsius range. A corresponding temperature difference between the cold and warm reservoirs (preferably greater than 30°C) is crucial.

[0036] The warm reservoir or the cold reservoir can have various designs. For example, the heat exchangers can absorb or release heat via an intermediate heat transfer medium. For this purpose, the heat exchangers can be arranged in tanks containing a heat transfer medium (e.g., water), which is charged with heat or discharged with heat by one or more additional heat exchangers. Furthermore, the heat exchangers can absorb heat directly from or release heat to another heat transfer medium (e.g., air or water). The additional heat transfer medium can be conducted in an open (e.g., to the atmosphere) or closed heat transfer flow.

[0037] In embodiments, the heat exchanger has a third side configured to receive a heated heat transfer medium (e.g., hot water from the heat exchanger) in the same flow direction as the heat transfer medium of the first side. This embodiment is particularly suitable when an unlimited or very large or continuously renewed amount of heat is available for the first heat reservoir. Such a heat source can be, for example, a chemical process that continuously generates waste heat or a geothermal source. The warm side of a heat pump is also suitable because it continuously generates heat.

[0038] In a further embodiment, the heat exchanger has a fourth side to receive cooled heat transfer medium (e.g., cold water) in the same flow direction as the heat transfer medium on the second side. This embodiment is particularly suitable when an unlimited, very extensive, or continuously renewed heat sink is available for the second heat reservoir. Such a heat sink can be, for example, a large geothermal storage facility, a flowing body of water, or an air-cooled (preferably forced-air) exhaust air heat exchanger. The cold side of a heat pump is also suitable, as it continuously dissipates heat.

[0039] The heat exchanger can also have both a third and a fourth side.

[0040] In particular, the arrangement according to the invention can be connected downstream of a heat pump. This heat pump can, for example, perform a cooling function in summer operation and a heating function in winter operation. The system according to the invention can then advantageously utilize the waste heat in summer operation and the cold side of the heat pump in winter operation.

[0041] The heat exchanger is designed and constructed according to well-known engineering principles. Pressure resistance is particularly crucial here. The individual sides (first to fourth sides) are separated from each other by the heat exchanger's walls. This prevents the heat transfer media from mixing between the individual sides.

[0042] Preferably, the heat exchanger is operated in countercurrent or cross-countercurrent.

[0043] Typical parameters of the arrangement according to the invention are: Heat transfer medium: Ethanol, 99.9%, (or other n-alcohols) Maximum volume of the working chambers: 50 ml - 500 l (0.5 kW - 5 MW) Maximum volume of the pump chambers: approx. 50 ml - 500 I (0.5 kW - 5 MW) Maximum plunger stroke: 25 mm - 1300 mm Crankshaft speed at the connecting rod engagement point: 0.1 - 5 1 / sec Pressure of the heat transfer medium on the first side of the heat exchanger: absolute: 1 - 5 bar Pressure of the heat transfer medium on the second side of the heat exchanger: 200 - 8000 bar Actuators, control elements, such as valves have control times between 1 - 100 ms The flow velocities are between 0.01 - 10 m / s.

[0044] The wall thicknesses of the structural elements (cylinder wall, piston wall, tube wall) comply with the Pressure Equipment Directive.

[0045] The inlet and thus the outlet temperatures of the heat transfer medium at the inlets and outlets of the heat exchanger depend on the temperatures of the available heat reservoirs.

[0046] The lowest temperature difference (temperature difference between the exiting heat transfer medium on the first side and the incoming heat transfer medium on the second side of the heat exchanger) for an efficient system is approximately 3-10 K (temperature: 3-5 K means approximately 35-25% overall efficiency). Since efficiency is highly nonlinear with temperature, a temperature of 1 K means approximately 80% overall efficiency. Designs outside the above-mentioned parameters are of course possible. These parameters are guidelines only.

[0047] In principle, the system can be operated in two ways.

[0048] In a first procedure (“isobaric operation”), there is an open connection between the outlet of the second side of the heat exchanger and the working chamber of the first double cylinder. With this procedure, the movement of the double pistons of the first and second double cylinders is only reversed at the reversal points of the double piston movement by switching the heat transfer medium to the working chamber of the second double cylinder. During the reversal, the second double cylinder becomes the first double cylinder, and the first double cylinder then assumes the previous function of the second double cylinder. The pressure of the heat transfer medium remains largely constant and is continuously identical in the heat exchanger to the pressure in the working chamber of the first double cylinder. Any pressure peaks, for example during switching, can optionally be buffered by the pressure accumulator.A minimum pressure of 50 bar in the heat exchanger has proven advantageous for isobaric operation. The system thus operates continuously. The heat transfer medium flows continuously through the heat exchanger.

[0049] In a second procedure (“isochoric operation”), the heat transfer medium is enclosed in the second side of the heat exchanger during heating, i.e. the inlet and outlet of the second side of the heat exchanger are closed during heat transfer between the first and second sides. This is achieved, for example, by a check valve preventing backflow from the heat exchanger and another valve closing the entry of the heat transfer medium into a working chamber. The heat transfer in the heat exchanger thus causes a pressure increase at constant volume. After sufficient heat transfer (heat transfer from the first to the second side of the heat exchanger), the valve to the working chamber of the first double cylinder is opened. The heat transfer medium expands in the working chamber and moves the piston in the manner described above.Once the heat transfer medium has expanded, the valve between the working chamber and the heat exchanger is closed again, and heating of the incoming heat transfer medium begins. With this procedure, it is important to ensure that the expansion of the heat transfer medium is sufficient to reach the reversal point of the double piston movement in each stroke. The arrangement operates quasi-continuously.

[0050] The required parameters, material characteristics and design values ​​are known and the entire process can be calculated using both methods.

[0051] A first embodiment of the method according to the invention for operating the arrangement according to the invention provides that the heat transfer medium absorbs heat in the heat exchanger, expands thermally without phase change and expanding heat transfer medium enters the working chamber of the first double cylinder and the working chamber expands by displacement of the double piston, and in the process: ◯ cooled heat transfer medium is moved from the pumping chamber of the first double cylinder to an inlet on the second side of the heat exchanger, ◯ Heat transfer medium is moved from the working chamber of the second double cylinder to the first heat reservoir and from there as heated heat transfer medium to an inlet of a first side of the heat exchanger, ◯ Heat transfer medium is supplied from an outlet of the first side of the heat exchanger as cooled heat transfer medium to the second heat reservoir, ◯ Heat transfer medium is moved from the second heat reservoir into the pump chamber of the second double cylinder.

[0052] A second embodiment of the method according to the invention for operating the arrangement according to the invention provides that the heat transfer medium absorbs heat in the heat exchanger, expands thermally without phase change and expanding heat transfer medium enters the working chamber of the first double cylinder and the working chamber expands by displacement of the double piston, and in the process. ◯ cooled heat transfer medium is moved from the pumping chamber of the first double cylinder to an inlet on the second side of the heat exchanger, ◯ to divide the heat transfer medium from the working chamber of the second double cylinder and to move a first partial flow to the first heat reservoir and from there as heated heat transfer medium to an inlet of a first side of the heat exchanger and a second partial flow directly to the inlet of the first side of the heat exchanger, ◯ Heat transfer medium from an outlet of the first side of the heat exchanger is divided into two partial flows as cooled heat transfer medium in the ratio of the two partial flows of the previous step, wherein a first partial flow is fed to the second heat reservoir and a second partial flow to the first heat reservoir, ◯ Heat transfer medium is moved from the second heat reservoir into the pump chamber of the second double cylinder.

[0053] A third embodiment of the method according to the invention for operating the arrangement according to the invention provides that the heat transfer medium absorbs heat in the heat exchanger, expands thermally without phase change and expanding heat transfer medium enters the working chamber of the first double cylinder and the working chamber expands by displacement of the double piston, and in the process: ◯ cooled heat transfer medium is moved from the pumping chamber of the first double cylinder to an inlet on the second side of the heat exchanger, ◯ Heat transfer medium from the working chamber of the second double cylinder is supplied as a first inflow to an inlet of a first side of the heat exchanger, wherein the heat transfer medium mixes there with a second inflow from the first heat reservoir, ◯ Heat transfer medium from an outlet of the first side of the heat exchanger is divided into two partial flows as a cooled heat transfer medium in the ratio of the two inflows, whereby a first partial flow is fed to the second heat reservoir and a second partial flow to the first heat reservoir, ◯ Heat transfer medium is moved from the second heat reservoir into the pump chamber of the second double cylinder.

[0054] The invention is not limited to the embodiments illustrated and described, but also encompasses all embodiments having the same effect within the meaning of the invention. Furthermore, the invention is not limited to the specifically described combinations of features, but can also be defined by any other combination of specific features of all the individual features disclosed as a whole, provided that the individual features are not mutually exclusive or a specific combination of individual features is not explicitly excluded. Figures Fig. 1 shows a schematic flow diagram for the device according to the invention in a particularly simple embodiment with the single double cylinder pair Z11, Z12. Fig. 2 shows schematically a further development of the circuit according to Fig. 1 with another double cylinder pair 2Z21, 2Z22 and a pressure buffer storage 2P1. Fig. 3 shows schematically a further development of the circuit according to Fig. 2. The pressure buffer tank is no longer included, but can be added again if necessary. An additional hot water circuit, 3W131, has been added on a third side of heat exchanger 3W1. Fig. 4 shows schematically a further development of the circuit according to Fig. 2. The pressure buffer tank is no longer included, but can be added again if necessary. An additional cold media circuit (water-based or using nitrogen or another gas) 4W141 has been added on a fourth side of heat exchanger 4W1. Fig. 5 shows schematically a further development of the circuit according to Fig. 2. The pressure buffer tank is no longer included, but can be added again if necessary. A branch 5T1 of the outlet 5L2 from the working chambers 5Z111, 5Z121, 5Z211, 5Z221 of the double cylinder pairs 5Z11, 5Z12 and 5Z21, 5Z22 has been added. Branch 5T1 directs a portion of the outlet 5L2 to the inlet 5W11E of the heat exchanger 5W1. The necessary check valve, which prevents backflow into the outlet 5L2, is not shown. At branch 5T2, a portion of the heat transfer medium exiting from the outlet 5W11A is returned to the warm reservoir 5WR. Fig. 6 shows schematically the procedure to create from one of the arrangements according to Fig. 2 to Fig. 5 to generate energy. The first double cylinder pair 6Z11, 6Z12 and the second double cylinder pair 6Z21, 6Z22 engage the common crankshaft 6KW. The phase shift of 90° is indicated by the missing projection of the crankshaft 6KW at the point of application of the push rod 6S1 of the first double cylinder pair 6Z11, 6Z21 on the crankshaft 6KW compared to the projection of the crankshaft 6KW at the point of application of the push rod 6S2 of the second double cylinder pair 6Z21, 6Z22. In the variant shown, the projection of the crankshaft KW is perpendicular to the drawing plane due to the phase shift and is therefore not visible in the projected image. The crankshaft 6KW is mounted on several bearings 6WL in order to be able to absorb the forces that arise. The 67KW crankshaft transmits the translational movement of the plungers in the twin cylinders 6Z11, 6Z12, 6Z21, 6Z22 to the 6GT gearbox.The gearbox delivers a speed higher than that of the crankshaft (6KW) to the generator (6GE), which is used to generate electricity. Fig. Figure 7 shows a schematic and perspective section through the first double cylinder pair 7Z11, 7Z12 and the second double cylinder pair 7Z21, 7Z22. The 90° phase shift between the double piston pairs 7Z113, 7Z123 and 7Z213, 7Z223 is indicated by the fact that the plungers 7Z113, 7Z123 of the first double cylinder pair 7Z11, 7Z12 have reached a reversal point (dead center) of their movement, while the plungers 7Z213, 7Z223 of the second double cylinder pair 7Z21, 7Z22 have only reached the middle of their movement between two reversal points. The movement of plunger 7Z123 and (indirectly via push rod 7ZZ1) plunger 7Z113 is transmitted to crankshaft 7KW via push rod 7S1 and connecting rod 7SP1. Likewise, the movement of plunger 7Z223 and (indirectly via push rod 7ZZ2) plunger 7Z213, as well as push rod 7S2 and connecting rod 7SP2, is transmitted to crankshaft KW.The 90° phase shift can also be seen from the position of the inclination of the connecting rods 7SP1 and 7SP2. Fig. Figure 8 shows schematically and in perspective the relationships of the Fig. 7 with the twin cylinders 8Z11, 8Z12, 8Z21, and 8Z22 closed (not a sectional view). The movement of the plungers (including the push rod 8ZZ1) of the first twin cylinder pair 8Z11 and 8Z12 is transmitted to the crankshaft 8KW via the push rod 8S1 and the connecting rod 8SP1. Likewise, the movement of the plungers (including the push rod 8ZZ2) of the second twin cylinder pair 8Z21 and 8Z22 is transmitted to the crankshaft KW via the push rod 8S2 and the connecting rod 8SP2. The 90° phase shift between the twin cylinder pairs can also be seen from the inclination of the connecting rods 8SP1 and 8SP2. Fig. Figure 9 shows schematically an embodiment of the Fig. 1 for isochoric operation, in which two additional valves (9V51, 9V52) are arranged directly on the heat exchanger 9W1. ExamplesExample 1

[0055] The following description of the arrangement refers to Fig. 1. A particularly simple embodiment is shown with only one double cylinder pair Z11, Z12. This embodiment is particularly suitable for isobaric operation. The two pistons (plungers) Z113, Z123 are connected to each other via the rigid mechanical coupling ZZ1 in such a way that they operate in push-pull operation. This can be seen from the fact that in the illustration Fig. 1 the working chamber Z111 of the first double cylinder Z11 is expanded almost to its maximum and as a result the pumping chamber Z112 of the first double cylinder Z11 is almost completely compressed. The valves V12 and V21 are closed, while the valves V11 and V22 are open. Due to the movement transmission through the rigid mechanical connection (here a piston rod (push rod)) ZZ1, the movement of the plunger Z113 is transferred to the plunger Z123. Since the second double cylinder Z12 is arranged mirror-symmetrically opposite the first double cylinder Z11, the movement of the rigid mechanical coupling ZZ1 causes the working chamber Z121 in the second double cylinder Z12 to be almost completely compressed and the pumping chamber Z122 to be almost completely expanded.

[0056] The mechanical power is extracted by means of a connecting rod (not shown) that extends through the wall Z114 of the first double cylinder Z11 and / or through the wall Z124 of the second double cylinder Z12 parallel to the direction of movement (preferably coaxial) of the rigid mechanical connection ZZ21. A generator for power generation is connected to this connecting rod via a crank mechanism and a gear. Fig. Figures 6 to 8 show examples of such mechanical couplings to a generator.

[0057] In an alternative modification of the present embodiment, a directly connected linear generator (with counter-rotating masses) is used to generate energy.

[0058] In order to integrate the arrangement according to the invention into Fig. To bring the pump chamber Z112 of the first double cylinder Z11 into the position shown in Figure 1, during compression of the pump chamber Z112 of the first double cylinder Z11, heat transfer medium is fed from the pump chamber Z112 via the pipe L3 between the check valves R1 to the pipe L5 and through the inlet W12 on the second side W12 of the heat exchanger. The check valves R1 prevent the heat transfer medium from flowing into the cold reservoir R1.

[0059] Due to the simultaneous expansion of the pumping chamber Z122 of the second double cylinder Z12, heat transfer medium is drawn from the cold reservoir through the first of the check valves R2 in the flow direction and fed via pipe L4 into the pumping chamber Z122 of the second double cylinder Z12. The working chamber Z121 of the second double cylinder Z12 is emptied via valve V22, and the heat transfer medium is moved via pipe L2 toward the warm reservoir WR. In the warm reservoir WR, the heat transfer medium absorbs heat and is moved to the inlet W11E of the first side W11 of the heat exchanger W1.

[0060] The warm reservoir WR is continuously heated from a waste heat source via the heat exchanger WT. The cold reservoir KR is cooled via the heat exchanger WT. Optionally, heat can be added to or removed from only one of the heat reservoirs WR or KR, if the necessary temperature difference is achieved, for example, by a particularly high temperature in the warm reservoir WR or a particularly low temperature in the cold reservoir KR. In this case, one of the reservoirs WR or KR can be designed as an air heat exchanger, through which heat is extracted from the ambient air (as a warm reservoir) or transferred to it (as a cold reservoir).

[0061] In the heat exchanger W1, the heat transfer medium on the first side W11 of the heat exchanger W1 is guided in countercurrent to the heat transfer medium on the second side W12.

[0062] Heat is transferred from the first side W11 to the second side W12 of the heat exchanger W1. During this heat transfer, the heat transfer medium on the first side W11 of the heat exchanger W1 contracts. At the same time, the heat transfer medium on the second side W12 of the heat exchanger W1 thermally expands. Since the check valves R1, R2 prevent the heat transfer medium from flowing back into the cold reservoir KR or one of the pump chambers Z112 or Z122, the only possible direction of expansion of the heat transfer medium on the second side W12 is towards the outlet W12A of the second side of the heat exchanger W1. During the thermal expansion, the heat transfer medium flows out of the heat exchanger.

[0063] The heat transfer medium exits heated at the outlet W12A of the second side W12 of the heat exchanger W1 and is fed via the pipe L1 and the valve V11 to the working chamber Z111 of the first double cylinder Z11.

[0064] The heat transfer medium of the first side W11 exits cooled at the outlet W11A of the first side W11 of the heat exchanger W1 and is fed to the cold reservoir via the pipe L6.

[0065] When the working chamber Z111 has expanded to its maximum, the valves V11 and V22 are closed via a camshaft that is operatively connected to the mechanical coupling ZZ1, while the valves V12 and V21 are opened. Since the heat transfer and thermal expansion of the heat transfer medium in the heat exchanger W1 continue continuously, the expanding heat transfer medium is now directed into the working chamber Z121 of the second double cylinder Z12 and the movement of the double pistons Z113 and Z123 is reversed. The double cylinders thus swap their previous mode of operation, i.e. in the double cylinder Z11, the working chamber Z111 is now compressed and the pumping chamber Z112 expands, while in the double cylinder Z12, the working chamber Z121 expands and the pumping chamber Z122 is compressed.Now it is the check valve pair R2 that prevents backflow of heat transfer fluid from the pump chamber Z122 into the cold reservoir KR, while cool heat transfer medium is sucked into the pump chamber Z112 of the first double cylinder Z11 via the check valve R1. essential parameters of the arrangement: Heat transfer medium: Ethanol, 99.9%, (n-alcohols) maximum volume of the working chambers Z111, Z121: 5 L Maximum volume of pump chambers Z112, Z122: see above Maximum stroke of plungers Z113, Z123: 200 mm Crankshaft speed at the connecting rod engagement point: 1 1 / sec Pressure of the heat transfer medium on the first side of the heat exchanger W1: absolute: 1 bar Pressure of the heat transfer medium on the second side of the heat exchanger W1: 400 bar Temperature of the heat transfer medium at the inlet W11E of the first side of the heat exchanger W1: 351 K Temperature of the heat transfer medium at the inlet W12E of the second side of the heat exchanger W1: 285 K (e.g. when cooling against the ground) Temperature of the heat transfer medium at the outlet W11A of the first side of the heat exchanger W1: 286 - 295 K Temperature of the heat transfer medium at the outlet W12A of the second side of the heat exchanger W1: 341 - 350 K Heat exchanger area: 65 m 2 (Convection surface between hot and cold side) Temperature of the warm reservoir: 351 - 373 K Temperature of the cold reservoir: 273 - 285 K Example 2

[0066] The Fig. The embodiment shown in Figure 2 is expanded compared to the first embodiment by a second pair of double cylinders 2Z21, 2Z22. The second pair of double cylinders 2Z21, 2Z22 is connected in parallel to the first pair of double cylinders downstream of the heat exchanger 2W1. Furthermore, in this embodiment, the pressure buffer reservoir 2P1 is connected to the supply line 2L1 to the parallel-connected double cylinder pairs 2Z11, 2Z12, 2Z21, 2Z22. One or more pressure reservoirs of this type can also be provided in the other embodiments and, if necessary, in any embodiment of the invention. They are preferably arranged in the lines that would be subject to strong pressure fluctuations. These are, on the one hand, the lines from the heat exchanger 2W1 to the double cylinders 2Z11, 2Z12, 2Z21, 2Z22 or in the lines that lead from the pump chambers 2Z112, 2Z12, 2Z212, 2Z222 to the heat exchanger 2W1.(In the other embodiments, the leading numbers of the reference symbols mentioned are to be replaced by the corresponding drawing number.).

[0067] The positions of plungers 2Z213, 2Z223 of the second double cylinder pair 2Z21, 2Z22 are phase-shifted by 90° compared to the positions of plungers 2Z113, 2Z123 of the first double cylinder pair 2Z11, 2Z12. This means that when the plungers 2Z113, 2Z123 of the first double cylinder pair 2Z11, 2Z12 reach their end point (lower in the drawing) (lower reversal point - corresponds to 0°), the plungers 2Z213, 2Z223 of the second double cylinder pair 2Z21, 2Z22 have traveled half (corresponding to 90°) of their respective piston travel. The movement of a double piston from a first dead center via the second dead center back to the first reversal point is considered a 360° movement. This is reflected in a complete (360°) rotation of the crankshaft when a crankshaft drive is connected.

[0068] Due to the phase shift of 90° of the double piston positions between the first double cylinder pair 2Z11, 2Z12 and the second double cylinder pair 2Z21, 2Z22, continuous operation of the arrangement from any position of the double pistons is guaranteed after a single start-up of the arrangement.

[0069] The inlet and outlet connections of the working clamps 2Z211, 2Z221 of the second double cylinder pair 2Z21, 2Z22 correspond to those of the first double cylinder pair 2Z11, 2Z12. Thus, the heat transfer medium flows from the heat exchanger 2W1 to the second double cylinder pair 2Z21, 2Z22 via pipe 2L1. The heat transfer medium is supplied from the cold reservoir 2KR via pipes 2L9 and 2L10, which are connected in the same way as pipes 2L3, 2L4 of the first double cylinder pair 2Z11, 2Z12.

[0070] The heat transfer medium is discharged via a branch of pipe 2L2 toward the warm reservoir. The valves 2V11, 2V12, 2V21, 2V22, 2V31, 2V32, 2V41, and 2V42 of the two double-cylinder pairs 2Z11, 2Z12, 2Z21, and 2Z22 are controlled by a common camshaft (not shown). The camshaft engages the mechanical coupling 2ZZ1 of the twin pistons 2Z113, 2Z123 of the first twin cylinder pair 2Z11, 2Z12 and controls the valves 2V11, 2V12, 2V21, 2V22, 2V31, 2V32, 2V41, and 2V42 depending on the position of the mechanical coupling 2ZZ1 of the twin pistons 2Z113, 2Z123 of the first twin cylinder pair 2Z11, 2Z12. This creates a passive control of the valves that does not require any electronic or hydraulic control elements. The valve control is purely mechanical and therefore advantageously very robust.

[0071] The camshaft controls valves 2V11, 2V12, 2V21, and 2V22 as described in the first embodiment. When the double pistons (plungers) 2Z113 and 2Z123 have reached the middle of their piston travel, the double pistons 2Z213 and 2Z223 of the second double cylinder pair 2Z21 and 2Z22 are at their reversal point, where the working chamber 2Z211 of the first double cylinder 2Z21 of the second double cylinder pair 2Z21 and 2Z22 is maximally compressed and the working chamber 2Z221 of the second double cylinder 2Z22 of the second double cylinder pair 2Z21 and 2Z22 is maximally expanded. The camshaft now opens valves 2V31 and 2V42 and simultaneously closes valves 2V32 and 2V41. As a result, heat transfer medium flows into the working chamber 2Z211 of the first double cylinder 2Z21 of the second double cylinder pair 2Z21, 2Z22.The incipient piston movement forces heat transfer medium from the pumping chamber 2Z212 of the first double cylinder 2Z21 of the second double cylinder pair 2Z21, 2Z22 toward the heat exchanger 2W1. At the same time, the heat transfer medium is moved from the working chamber 2Z221 of the second double cylinder 2Z22 of the second double cylinder pair 2Z21, 2Z22 through the pipe 2L2 toward the warm reservoir WR and from there to the inlet 2W11E of the first side 2W11 of the heat exchanger 2W1. At the same time, heat transfer medium is drawn from the cold reservoir KR by the pumping chamber 2Z222 of the second double cylinder 2Z22 of the second double cylinder pair 2Z21, 2Z22. When the movement of the double pistons 2Z213, 2Z223 of the second double cylinder pair 2Z21, 2Z22 reaches a reversal point, the camshaft is controlled in such a way that the valves 2V31 and 2V42 are closed and at the same time the valves 2V32 and 2V41 are opened.This swaps the functions of the first and second double cylinders 2Z21 and 2Z22 of the second double cylinder pair 2Z21, 2Z22. The operating mode of the second double cylinder pair 2Z21, 2Z22 is thus the same as that of the first double cylinder pair 2Z11, 2Z12, with only a phase shift of 90°. The arrangement could be expanded to include a third double cylinder pair or even further double cylinder pairs. The phase shift of the double cylinder pairs relative to each other is then selected so that the force applied to the crankshaft is as uniform as possible. This is achieved, for example, by the phase shift for more than two double cylinder pairs being the quotient of 360° and the number of double cylinder pairs.

[0072] The essential parameters of the arrangement according to embodiment 2 correspond to those of the first embodiment, whereby all four double cylinders 2Z11, 2Z12, 2Z21, 2Z22 are identical. Example 3

[0073] Embodiment 3 is a modification of the arrangement according to embodiment 2. In the event that large, constantly regenerated heat quantities are continuously available (e.g., as waste heat from continuous processes), the effectiveness of the arrangement can be further increased by additionally introducing heat transfer medium into a third side 3W13 of the heat exchanger 3W1. This preferably occurs countercurrently to the heat transfer medium flow of the second side 3W12 of the heat exchanger 3W1. The third side 3W13 of the heat exchanger does not have to run from the outlet of the second side 3W12A to the inlet 3W12E of the second side 3W12, but can advantageously leave the heat exchanger 3W1 again after approximately two-thirds of the length of the second side 3W12 of the heat exchanger 3W1. A precise design and optimization of the heat exchanger 3W1 is carried out depending on the available heat quantities, their temperatures, etc., preferably by means of computer-aided simulation.

[0074] The essential parameters of the arrangement according to embodiment 3 correspond to those of the first embodiment. Example 4

[0075] Embodiment 4 is a further modification of the arrangement according to embodiment 2. In the event that a large, constantly regenerating heat sink is continuously available (e.g. when charging geothermal energy storage systems, cooling by a flowing water, cooling or winter operation), the effectiveness of the arrangement can be further increased by additionally introducing heat transfer medium into a fourth side 4W14 of the heat exchanger 4W1.

[0076] This preferably occurs countercurrently to the heat transfer medium flow of the first side 4W11 of the heat exchanger 4W1. The fourth side 4W14 of the heat exchanger does not need to extend from the outlet 4W11A of the first side 4W11 to the inlet 4W11E of the first side 4W11, but can advantageously leave the heat exchanger 4W1 after only a portion of its length, in particular two-thirds of the length of the first side 4W11 of the heat exchanger 4W1. A precise design and optimization of the heat exchanger 4W1 is carried out depending on the available heat quantities, their temperatures, etc., preferably by means of computer-aided simulation.

[0077] The circuits according to embodiment 3 and embodiment 4 can be combined. The heat exchanger W1 would then have both a third and a fourth side in the form described.

[0078] The essential parameters of the arrangement according to embodiment 4 can otherwise correspond to those of the first embodiment. Example 5

[0079] Embodiment 5 is a further modification of the arrangement according to embodiment 2. The heat transfer medium exiting the working chambers 5Z111, 5Z121, 5Z211, 5Z221 is guided through line 5L2 toward the heat reservoir 5WR. However, in the working chambers 5Z111, 5Z121, 5Z211, 5Z221, the heat transfer medium has only lost a small amount of temperature. To increase the effectiveness of the arrangement, it is therefore possible to divide the heat transfer medium flow in the pipe 5L2 into two partial flows at a splitting point 5L21 before reaching the warm reservoir 5WR. The first partial flow is guided to the warm reservoir 5WR, as already described. The second partial flow is combined with the heat transfer medium flowing via line 5L7 to the inlet of the first side 5W11 of the heat exchanger 5W1.In the heat exchanger, the heat transfer medium flow from the first side 5W11 of the heat exchanger 5W1 transfers a large portion of its heat to the heat transfer medium flow from the second side 5W12 of the heat exchanger 5W1. After leaving the heat exchanger 5W1, the heat transfer medium flow from the first side of the heat exchanger 5W1 is divided at a second division point 5T2 in the same ratio as the heat transfer medium flow at the first division point 5T1. A first portion of the heat transfer medium flow is directed, as described, to the cold reservoir 5KR, while the second portion is directed via line 5L8 to the warm reservoir 5WR, where it is combined with the heat transfer medium flow arriving via line 5L22. The ratio of the distribution of the heat transfer flows at the distribution points 5T1, 5T2 is identical and in one design is 70:30, with 30% being branched off from the pipe 5L2 in the direction of the heat exchanger 5W1.after passing through the heat exchanger to the warm reservoir 5WR.

[0080] The other parameters of the arrangement according to embodiment 5 correspond to those of the first embodiment. Example 6

[0081] The embodiment 6 (see Fig. 9) is a variant of embodiment 1 suitable for isochoric operation. The valve 9V51 is designed to close the inlet and the valve 9V52 is designed to close the outlet of the heat exchanger 9W1 in a controlled manner. During operation, cold heat transfer medium flows through the valve 9V51 into the second side 9W12 of the heat exchanger 9W1. In the process, the heat transfer medium already located in the second side 9W12 of the heat exchanger 9W1 is displaced. As soon as the heat transfer medium in the second side 9W12 has been completely replaced by cold heat transfer medium, the valves 9V51 and 9V52 are closed. This encloses the heat transfer medium in the heat exchanger 9W1. Heated heat transfer medium flows on the first side 9W11 and now heats the heat transfer medium on the second side 9W12 of the heat exchanger 9W1.The heat transfer to the second side 9W12 thus occurs to a largely static heat transfer medium, with the heat transfer medium flowing on the heat-emitting side 9W11. The heat transfer medium on the second side 9W12 of the heat exchanger develops a significant pressure increase (up to approximately 8000 bar) due to the desired thermal expansion, which is not possible due to the closed valves. To limit the pressure increase to the heat exchanger 9W1 as much as possible, the valves 9V51 and 9V52 are arranged as close as possible to the inlet and outlet (9W12A and 9W12A, respectively) of the heat exchanger 9W1. After the heat transfer is complete, the valves 9V51 and 9V52 are opened. The outlet valve 9V52 opens before the inlet valve 9V51 in order to direct the pressure propagation that begins with the valve opening as far as possible towards the working chamber 9Z111 of the first double cylinder.Subsequently, valve 9V52 is also opened to allow the flow of cold heat transfer medium, after which the heating cycle begins anew. The opening of valve 9V52 at the heat exchanger outlet 9W12A is synchronized with the inlet valves (9V11, 9V21) into the working chambers 9Z111, 9Z121 of the double cylinder pair in such a way that the expanding heat transfer medium can flow into the working chamber 9Z111, which functions as the first working chamber in the current cycle. In this example, a pressure buffer reservoir 9P2 is also provided in the supply line to the inlet of the heat exchanger 9W1.

[0082] The other parameters (with the exception of the pressure ratios) of the arrangement according to embodiment 6 correspond to those of the first embodiment. Reference symbol

[0083] For your understanding: In the figures, the reference symbols are preceded by the respective drawing number. Example: the check valve that is shown in Fig. 1 is marked as R5, carries in Fig. 3 the designation 3R5 and in Fig. 5 is designated 5R5. However, the function is identical in each illustration. Reference symbols preceded by a number only appear in the figure designated by this number. Example: the pressure accumulator 2P1 is only used in the Fig. 2. The use and representation of individual components only in one or part of the figures and thus in part of the embodiments does not mean that a use and representation in one of the other embodiments is not possible. KR cold reservoir WR warm reservoir WT heat exchanger in the cold reservoir or warm reservoir W1 heat exchanger W11 first side of the heat exchanger W12 second side of the heat exchanger 3W13 third side of the heat exchanger 4W14 fourth side of the heat exchanger 3W131 Heat carrier flow of the third side of the heat exchanger 4W141 Heat carrier flow of the fourth side of the heat exchanger W11E Inlet of the first side of the heat exchanger W11A Outlet of the first side of the heat exchanger W12E Inlet of the second side of the heat exchanger W12A Output of the second side of the heat exchanger L1... L10 pipelines S1 Push rod of the first double cylinder pair S2 Push rod of the second double cylinder pair SP1 connecting rod of the first double cylinder pair SP2 connecting rod of the second double cylinder pair R1... R4 check valves Z11 first double cylinder of the first double cylinder pair Z12 second double cylinder of the first double cylinder pair Z21 first double cylinder of the second double cylinder pair Z22 second double cylinder of the second double cylinder pair Z111 Working chamber of the first double cylinder of the first double cylinder pair Z121 Working chamber of the second double cylinder of the first double cylinder pair Z211 Working chamber of the first double cylinder of the second double cylinder pair Z221 Working chamber of the second double cylinder of the second double cylinder pair Z112 Pump chamber of the first double cylinder of the first double cylinder pair Z122 Pump chamber of the second double cylinder of the first double cylinder pair Z212 Pump chamber of the first double cylinder of the second double cylinder pair Z222 Pump chamber of the second double cylinder of the second double cylinder pair Z113 Double piston (plunger) of the first double cylinder of the first double cylinder pair Z123 Double piston (plunger) of the second double cylinder of the first double cylinder pair Z213 Double piston (plunger) of the first double cylinder of the second double cylinder pair Z223 Double piston of the second double cylinder of the second double cylinder pair Z114 Wall of the first double cylinder of the first double cylinder pair Z124 Wall of the second double cylinder of the first double cylinder pair Z214 Wall of the first double cylinder of the second double cylinder pair Z224 Wall of the second double cylinder of the second double cylinder pair ZZ1 mechanical coupling of the double pistons of the first double cylinder pair ZZ2 mechanical coupling of the double pistons of the second double cylinder pair V11 Valve for the entry of the heat transfer medium into the working chamber of the first double cylinder of the first double cylinder pair V12 Valve for the outlet of the heat transfer medium from the working chamber of the first double cylinder of the first double cylinder pair V21 Valve for the entry of the heat transfer medium into the working chamber of the second double cylinder of the first double cylinder pair V22 Valve for the outlet of the heat transfer medium from the working chamber of the second double cylinder of the first double cylinder pair V31 Valve for the entry of the heat transfer medium into the working chamber of the first double cylinder of the second double cylinder pair V32 Valve for the outlet of the heat transfer medium from the working chamber of the first double cylinder of the second double cylinder pair V41 Valve for the entry of the heat transfer medium into the working chamber of the second double cylinder of the second double cylinder pair V42 Valve for the outlet of the heat transfer medium from the working chamber of the second double cylinder of the second double cylinder pair 9V51 Valve for closing the inlet of the second side of the heat exchanger in isochoric operation 9V52 Valve for closing the outlet of the second side of the heat exchanger in isochoric operation P1, P2 pressure buffer memory T1, T2 special branching points of the heat transfer medium flows KW crankshaft 6GE generator 6GT transmission 6WL crankshaft abutment ➙ Flow direction of the warmer heat transfer medium ⇐ Flow direction of the cooler heat transfer medium

Claims

[1] Arrangement for converting thermal energy into mechanical energy, comprising at least a first and at least a second heat reservoir, wherein the temperature of the first heat reservoir (WR) is higher than that of the second heat reservoir (KR), a liquid heat transfer medium, a first double cylinder pair consisting of a first double cylinder with a first double piston (Z113) and a second double cylinder with a second double piston (Z123), wherein each double piston (Z113, Z123) divides the associated double cylinder into a working chamber (Z111, Z121) and a pumping chamber (Z112, Z122), wherein an expansion of the working chamber (Z111, Z121) causes a compression of the pumping chamber (Z112, Z122), at least one heat exchanger (W1), pipes connecting the double cylinders to the heat exchanger (W1) and the first and second heat reservoirs (WR, KR), and valves, characterized by , that o the first and second double pistons (Z113, Z123) are mechanically coupled in such a way that an expansion of the working chamber (Z111) of the first double cylinder (Z11) causes a compression of the working chamber (Z121) of the second double cylinder (Z12) and a compression of the working chamber (Z111) of the first double cylinder (Z11) causes an expansion of the working chamber (Z121) of the second double cylinder (Z12), ◯ the heat exchanger (W1) is designed such that heated heat transfer medium enters at an inlet W11E) of the first side (W11) of the heat exchanger (W1) and exits as cooled heat transfer medium at an outlet (W11A) of the first side (W11) of the heat exchanger (W1), and cooled heat transfer medium enters at an inlet (W12E) of the second side (W12) of the heat exchanger (W1) and exits as heated heat transfer medium at an outlet (W12A) of the second side (W12) of the heat exchanger (W1), wherein during the heat transfer from the first side (W11) to the second side (W12) of the heat exchanger (W1), the heat transfer medium on the first side (W11) contracts thermally and expands thermally on the second side (W12), wherein no phase transitions of the liquid heat transfer medium occur, o the heat transfer medium exhibits a thermal expansion that is greater than the volume by which the heat transfer medium is reduced compared to its uncompressed volume due to compressibility when the pressure increases, o the valves and pipes are arranged and configured such that they supply heated heat transfer medium from the outlet (W12A) of a second side (W12) of the heat exchanger (W1) to the working chamber of the first double cylinder, so that an expansion of the working chamber (Z111) of the first double cylinder (Z11) and a compression of the working chamber (Z121) of the second double cylinder (Z12) of the first double cylinder pair as well as a compression of the pumping chamber (Z112) of the first double cylinder (Z11) and an expansion of the pumping chamber (Z122) of the second double cylinder (Z12) take place, o when a reversal point of the double piston (Z113) of the first double cylinder (Z11) is reached, the functions of the first and second double cylinders (Z11, Z12) are reversed. [2] Arrangement according to claim 1, characterized by that the double pistons (Z113, Z123) are designed as plungers and / or the mechanical coupling is effected by means of a push rod (S1) which rigidly connects the two plungers (Z113, Z123) of the pump chambers of a double cylinder pair. [3] Arrangement according to claim 1 or 2, characterized by that the double pistons (Z113, Z123) have at least one thermal insulation layer to reduce the heat flow between the working chamber (Z111, Z121) and the pumping chamber (Z112, Z122) and / or the double cylinders have thermal insulation at least in the area of ​​the working chamber (Z111, Z121). [4] Arrangement according to one of the preceding claims, characterized bythat the volume of the pumping chamber (Z112) is reduced by the value compared to the volume of the working chamber (Z111), which corresponds to the volume expansion of the heat transfer medium in the heat exchanger (W1). [5] Arrangement according to one of the preceding claims, characterized by that the extraction of mechanical energy from the arrangement takes place at the mechanical coupling (S1) of the first and the second double piston or with a mechanical coupling (SP1) at one or both piston parts of a double piston (Z113, Z123) in the working chamber(s) (Z111, Z121) of a double cylinder pair. [6] Arrangement according to one of the preceding claims, characterized by that the valves are controlled via means connected to the push rod (S1). [7] Arrangement according to one of the preceding claims, characterized bythat the heat transfer medium in the heat exchanger (W1) has a maximum pressure between 200 bar and 8000 bar and / or that in a pipe from the outlet (W12A) of the second side (W12) of the heat exchanger (W1) to the inlet into the working chamber (Z111) and / or in a pipe from the pumping chamber (Z112) to the inlet (W12E) of the second side (W12) of the heat exchanger (W1) at least one pressure accumulator (P1, P2) is arranged, which buffers pressure fluctuations. [8] Arrangement according to one of the preceding claims, characterized by that the heat transfer medium is an alcohol, particularly preferably ethanol. [9] Arrangement according to one of the preceding claims, characterized bythat a second or further double cylinder pairs (Z21, Z22) are present in the arrangement and their piston positions are phase-shifted compared to the first double cylinder pair (Z11, Z12), wherein preferably when a second double cylinder pair (Z21, Z22) is present, the second double cylinder pair (Z21, Z22) is phase-shifted by 0° and 180°, preferably 90°, compared to the first double cylinder pair (Z11, Z12) and that when more than two double cylinder pairs are present, the phase shift of the double cylinder pairs among each other results from the relationship 360° / (number of all double cylinders). [10] Arrangement according to one of the preceding claims, characterized bythat the heat exchanger (W1) has a third side (3W13) which is designed to receive a heated heat transfer medium in the same flow direction as the heat transfer medium of the first side (W11) and / or that the heat exchanger (W1) has a fourth side (4W14) to receive cooled heat transfer medium (e.g. cold water) in the same flow direction as the heat transfer medium of the second side (W12). [11] Arrangement according to one of the preceding claims, characterized bythat the first heat reservoir (WR) is designed to be charged (heated) via a heat exchanger (WT) by means of heat from a technical or natural process, in particular waste heat from an industrial process, heat from a geothermal storage facility, geothermal heat, solar thermal energy or heat from a heat pump process, and / or that the second heat reservoir (KR) is designed to be discharged (cooled) via a heat exchanger (WT) in the direction of a geothermal storage facility, another heat storage facility, into the environment or to a heat pump. [12] Method for operating an arrangement according to one of claims 1 to 11, characterized bythat there is an open connection between the outlet (W12A) of the second side (W12) of the heat exchanger (W1) and the working chamber (Z111) of the first double cylinder (Z11), and only at the reversal points of the double piston movement by switching the heat transfer medium to the working chamber (W121) of the second double cylinder (Z12) is a reversal of movement of the double pistons (Z113, Z123) of the first and second double cylinders (Z11, Z12) achieved and the second double cylinder (Z12) becomes the first double cylinder (Z11) upon reversal and the first double cylinder (Z11) then receives the previous function of the second double cylinder (Z12), wherein the pressure of the heat transfer medium remains largely constant and thus the pressure in the heat exchanger (W1) is continuously identical to the pressure in the working chamber (Z111) of the first double cylinder (Z11). [13] Method for operating an arrangement according to one of claims 1 to 11 characterized bythat the inlet (W12E) and the outlet (W12A) of the second side (W12) of the heat exchanger (W1) are closed during the heat transfer between the first and the second side (W11, W12), and after sufficient heat transfer the valve to the working chamber of the first double cylinder is opened. [14] Method according to claim 12 or 13, characterized by that the heat transfer medium absorbs heat in the heat exchanger (W1), expands thermally without phase change and expanding heat transfer medium enters the working chamber (Z111) of the first double cylinder (Z11) and the working chamber (Z111) expands by displacement of the double piston (Z113), and in the process: o cooled heat transfer medium is moved from the pump chamber (Z112) of the first double cylinder (Z11) to the inlet (W12E) of the second side (W12) of the heat exchanger (W1), o heat transfer medium is moved from the working chamber (Z121) of the second double cylinder (Z12) to the first heat reservoir (WR) and from there as heated heat transfer medium to an inlet (W11E) of a first side (W11) of the heat exchanger (W1), o heat transfer medium from an outlet (W11A) of the first side (W11) of the heat exchanger (W1) is supplied as cooled heat transfer medium to the second heat reservoir (KR), o Heat transfer medium is moved from the second heat reservoir (WR) into the pump chamber (Z122) of the second double cylinder (Z12). [15] Method according to claim 12 or 13, characterized by that the heat transfer medium absorbs heat in the heat exchanger (W1), expands thermally without phase change and expanding heat transfer medium enters the working chamber (Z111) of the first double cylinder (Z11) and the working chamber (Z111) expands by displacement of the double piston (Z113), and thereby. ◯ cooled heat transfer medium is moved from the pump chamber (Z112) of the first double cylinder (Z11) to an inlet (W12E) of the second side (W12) of the heat exchanger (W1), ◯ heat transfer medium from the working chamber (Z121) of the second double cylinder (Z12) is divided and a first partial flow is moved to the first heat reservoir (WR) and from there as heated heat transfer medium to an inlet (W11E) of a first side (W11) of the heat exchanger (W1) and a second partial flow is moved directly to the inlet (W11E) of the first side (W11) of the heat exchanger (W1), o heat transfer medium from an outlet (W11A) of the first side (W11) of the heat exchanger (W1) is divided into two partial flows as cooled heat transfer medium in the ratio of the two partial flows of the previous step, wherein a first partial flow is fed to the second heat reservoir (KR) and a second partial flow is fed to the first heat reservoir (WR), o Heat transfer medium is moved from the second heat reservoir (KR) into the pump chamber (Z122) of the second double cylinder (Z12). [16] Method according to claim 12 or 13, characterized by that the heat transfer medium absorbs heat in the heat exchanger (W1), expands thermally without phase change and expanding heat transfer medium enters the working chamber (Z111) of the first double cylinder (Z11) and the working chamber (Z111) expands by displacement of the double piston (Z113), and in the process: ◯ cooled heat transfer medium is moved from the pump chamber (Z112) of the first double cylinder (Z11) to an inlet (W12E) of the second side (W12) of the heat exchanger (W1), ◯ Heat transfer medium from the working chamber (Z121) of the second double cylinder (Z12) is supplied as a first inflow to an inlet (W11E) of a first side (W11) of the heat exchanger (W1), wherein the heat transfer medium mixes there with a second inflow from the first heat reservoir (WR), ◯ Heat transfer medium from an outlet (W11A) of the first side (W11) of the heat exchanger (W1) is divided as cooled heat transfer medium into two partial flows in the ratio of the two inflows, whereby a first partial flow is fed to the second heat reservoir (KR) and a second partial flow to the first heat reservoir (WR), o Heat transfer medium is moved from the second heat reservoir (KR) into the pump chamber (Z122) of the second double cylinder (Z12). [17] Use of an arrangement according to one of claims 1 to 11 for performing mechanical work or for generating electrical energy. [18] Use according to claim 17, characterized bythat, to generate electrical energy, a hydraulic motor or push rod and crank system coupled via a hydraulic system acts on an AC generator or a DC generator, or a linear generator is used, preferably directly connected to the mechanical coupling of the double cylinders.

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