DEVICE FOR TRANSFERRING HEAT FROM A GASEOUS WORKING MEDIUM

Description

[0001] The invention relates to a device for transferring heat from a gaseous working medium to a heat exchanger medium by compressing the gaseous working medium according to claim 1, wherein the device comprises: a working line, wherein the volume enclosed by the working line is divided into at least two sections, namely a first and a second section, wherein the first section is configured to receive a pressure transmission medium and the second section is configured to receive and discharge the gaseous working medium, wherein at least one inlet and outlet valve is provided for receiving and discharging the gaseous working medium, wherein a first volume bounded by the first section is separated from a second volume bounded by the second section by a first separating layer that is movable in the working line, wherein the first separating layer is arranged such thatthat pressure differences between the first and second sections of the working line are compensated by a displacement of the first separating layer in the working line and a concomitant change in the size ratio between the first volume and the second volume, and a heat exchanger line for receiving the heat exchange medium.

[0002] Document WO 2017 / 101914 concerns a constant-pressure multi-chamber vessel, an energy converter, and an operating method. Document AT 506 796 A4 concerns a method for operating a heat engine and a heat engine for carrying out the method. Document WO 2006 / 111773 A2 concerns a heat pump.

[0003] For example, heat pumps are known from the prior art that are designed to supply preheated fresh air into an interior space, such as a building or a vehicle cabin. In this process, heat is transferred to a heat exchanger medium by means of compression of a working fluid. The efficiency of such a heat pump is highly dependent on the flow temperature of the working fluid and the pressures used. Conventional heat pumps, such as those used in building services engineering, can operate at pressures of just a few bar. Generally, using a higher operating pressure allows for higher efficiency. However, higher pressures also place greater demands on the materials used. Furthermore, such systems require a correspondingly larger amount of space.

[0004] One object of the invention is therefore to create a device for transferring heat that overcomes the aforementioned disadvantages and thus enables a compact design with high efficiency.

[0005] The present invention is disclosed in independent claim 1. Further embodiments are disclosed in the dependent claims.

[0006] The aforementioned problem is solved with a device of the type mentioned at the outset, in that, according to the invention, the heat exchanger line is coupled to the first section of the working line to bring about pressure equalization, in that the heat exchanger line is connected to the first section of the working line and a second separating layer is provided between these lines to separate the lines from each other, wherein the second separating layer is designed and arranged such that continuous pressure equalization is given between the heat exchanger line and the first section of the working line, wherein the second section of the working line has a heat dissipation section which is enclosed on the outside and inside by a two-part heat absorption section of the heat exchanger line, in that the working line has an inner wall and an outer wall encasing the inner wall.and a working medium gap is formed between the inner wall and the outer wall for guiding the working medium, wherein the inner wall encloses a channel through which a first part of the heat exchanger line is formed in the heat absorption section, and the heat exchanger line in the heat absorption section also has a shell wall enclosing the outer wall of the working line, through which a second part of the heat exchanger line in the heat absorption section is formed and bounded, wherein a heat exchange medium gap connected in parallel with the channel is formed between the outer wall of the working line and the shell wall of the heat exchanger line, so that a heat exchange medium guided in the heat absorption section of the heat exchanger line can flow around the working line on the outside via the heat exchange medium gap and on the inside via the channel.

[0007] The inventive design of the device makes it possible to operate within a very wide range of pressures. Since the working line in the heat transfer section can be surrounded on both sides by the heat exchanger medium, particularly efficient heat transfer to the heat exchanger medium can occur.

[0008] Another significant advantage is that the pressure coupling between the pressure transmission, heat exchanger medium, and working fluid creates a pressure equilibrium. This allows the walls of the working pipe in the heat transfer section to be considerably thinner than they would need to be without such pressure equalization. The walls only need to be designed to properly guide the first separation layer and ensure the mechanical stability of the pipes, since the pressure is largely the same on both the inside and outside of the working pipe walls. This means that the walls can be, for example, over 50% thinner than would be possible without this pressure equalization. As a result, the efficiency of heat transfer between the working fluid and the heat exchanger medium can be further increased.In absolute terms, the wall thicknesses in the heat emission or absorption section, with the exception of the wall thickness of the outer shell wall of the heat exchanger pipe, could be between 1 mm and 4 mm, in particular less than 10 mm.

[0009] The device according to the invention, which can be used, for example, in the form of a heat pump for a building or a vehicle, in particular an electric vehicle, can achieve COP values ​​in the range of 5 to 8.

[0010] The inlet and outlet valve need not be a single piece. Separate inlet and outlet valves are certainly possible. Multiple valves are also possible. The term "pressure of a line" refers to the pressure of the medium contained within the line; that is, pressure equalization between two lines means that pressure is equalized between the media contained within them.

[0011] Pressure equalization is preferably achieved in such a way that essentially no tensile or compressive stresses occur in the radial direction of the pipes. This allows the walls between the working medium and the heat exchanger medium in the heat transfer section to be extremely thin, thus enabling improved heat transfer.

[0012] The device according to the invention can function, for example, by transmitting cyclic pressure changes to the two separating layers via the pressure transmission medium. An increase in pressure leads at least to a displacement of the first separating layer, thus compressing and heating the working medium contained in the first section. The heated working medium then transfers the heat to the heat exchanger medium. The pressure is increased until the first separating layer reaches its end position, and after sufficient heat transfer, the outlet valve is opened to release the working medium. The pressure of the pressure transmission medium is then reduced, causing the first separating layer to move back into its original position, and fresh working medium is drawn into the second section via an inlet valve that is now opened.

[0013] In particular, it may be provided that the heat exchanger medium is at least partially gaseous. This could be, for example, heated steam; mixtures of gaseous and liquid states are also conceivable.

[0014] Furthermore, the heat exchanger medium can be a liquid, in particular water. The specifications always refer to the thermal conditions during the nominal operation of the device according to the invention and to the nominal value of the pressure and temperature range prevailing in the medium.

[0015] In particular, it may be provided that the pressure transmission medium in the first section of the working line is an oil.

[0016] The device according to the invention can of course contain the corresponding media or may even already be filled accordingly upon delivery.

[0017] Furthermore, it can be provided that the first separating layer is formed directly by the interface formed due to the surface tension of the liquid pressure transfer medium in relation to the gaseous working medium.

[0018] The aforementioned separation layers, i.e., the first and second separation layers, can each simply be defined by the boundary layer formed between two immiscible media. For example, separation layers can form at the interface between oil and air or oil and water. In these transition zones, the pipes can be oriented such that, due to the different densities of the media, an interface is formed that runs transversely, and especially perpendicularly, to the respective pipe cross-section, thus separating the media over a short distance. For instance, the pipes in the transition zone could be oriented vertically, creating a boundary between oil (as the pressure transmission medium) and air (as the working medium) by causing the oil, due to its higher density, to collect in the lower part of the vertical pipe section.

[0019] Alternatively, the first separating layer can be formed by a first separating agent provided for this purpose, which is preferably designed as a spatially displaceable first sealing element. Such a sealing element can, for example, be implemented as an O-ring or as a lip seal.

[0020] Furthermore, it can be provided that the heat exchanger line in the area of ​​the heat absorption section is designed symmetrically around a longitudinal axis.

[0021] In particular, it can be provided that the working line in the heat emission section is designed as a concentric double pipe, which is designed coaxial to the longitudinal axis of the heat exchanger line in the area of ​​the heat absorption section, wherein the working medium gap is formed between the inner wall and the outer wall of the double pipe and is limited by them, wherein the shell wall of the heat exchanger line surrounds the double pipe and the channel is enclosed by the inner wall of the double pipe.

[0022] Furthermore, the inner and outer walls can be configured to form a multi-toothed star in cross-section, which is particularly axially or point-symmetrical, with the star formed by the outer wall preferably being an enlargement of the star formed by the inner wall. This star-like configuration significantly increases the surface area of ​​each wall, thereby improving heat exchange between the working medium and the heat exchanger medium. Normally, the use of such structures in high-pressure systems is extremely difficult due to bending stresses occurring at the respective points. However, in this case, the pressure equalization between the media allows the use of complex geometries with thin walls despite high ambient pressures.The magnification is preferably achieved such that the outer star has the same geometric shape as the inner star and is simply a proportional enlargement of the inner star. By proportionally reducing the size of the outer star, it could therefore be brought into perfect alignment with the inner star.

[0023] In particular, it can be provided that the working line in a region of the heat dissipation section is designed such that the working medium gap narrows towards the at least one inlet and outlet valve. The gap width can be reduced by at least 20%, preferably 30%, particularly 50%, or 80% compared to the un-narrowed section of the working line. This further improves heat transfer.

[0024] Furthermore, it can be provided that the working line is distributed at least within the heat emission section across parallel connected branches.

[0025] In particular, the device can be designed for a nominal working pressure between 6 bar and 1000 bar, preferably between 50 bar and 100 bar, by designing the working line, the heat exchanger line, and the at least one inlet and outlet valve to withstand the nominal working pressure. Pressures of 1000 bar can be advantageous for hydrogen applications. If the device according to the invention is to be used as a heat pump, working pressures of, for example, at least 10 bar (i.e., pressures in the transfer medium or first section, which are then transferred to the remaining media) would be suitable, with 50 bar to 100 bar being particularly advantageous for this invention. The higher the pressure, the better the efficiency of the device.

[0026] The device according to the invention can be dimensioned in a wide variety of sizes. For small systems, a weight on the order of 10 kg and dimensions of less than 30 cm are possible, making the device particularly suitable for use in vehicles, for example. However, its use in large systems is also conceivable, in which case the device could weigh several tons and have a height of approximately 3 m. The device according to the invention is highly scalable with regard to its performance.

[0027] Furthermore, the device may include a pump for transmitting pressure to a pressure transmission medium contained in the first section of the working line, the pump preferably being designed as a rotary piston pump, piston pump, gear pump or vane pump.

[0028] In particular, the device may further include a heat exchanger, wherein the heat exchanger line is connected to the heat exchanger for the purpose of discharging heat.

[0029] Furthermore, the second separating layer can be formed by a second separating agent provided for this purpose, which is preferably designed as a spatially displaceable second sealing element, either as an elastic membrane fixed at its edges or as a whole that is spatially displaceable. The second sealing element can, for example, be designed as an O-ring or as a lip seal.

[0030] The present invention enables a design for the near-isothermal compression of gases using piston compressors. This reduces the energy required for heat exchange during gas compression, thereby increasing efficiency. Two resistances are fundamentally overcome during gas compression: 1. Resistance due to the reduction of volume. 2. By reducing the volume, the temperature is continuously increased, thus increasing the resistance to further compression.

[0031] If it is possible to continuously dissipate the heat energy during compression (i.e., to maintain a temperature that is as constant as possible), this results in a considerable reduction in energy consumption. With this design, or device according to the invention, an almost continuous dissipation of heat energy during the compression process can be achieved via a piston.

[0032] It should also be noted that the compressed and cooled working fluid can reach extremely low temperatures when it is released through the outlet valve. The discharged working fluid is ideally suited for all kinds of cooling applications, from room air conditioning to cold storage facilities and applications in the chemical industry.

[0033] The invention is explained in more detail below with reference to an exemplary and non-limiting embodiment, which is illustrated in the figures. These show Figure 1 a schematic representation of a device according to the invention, and Figure 2 a sectional view corresponding to the section line AB of the Fig. 1 .

[0034] In the following figures, unless otherwise stated, the same reference symbols denote the same features. Figure 1Figure 1 shows an embodiment of a device 1 according to the invention for transferring heat from a gaseous working medium M2 to a heat exchanger medium M3 by compressing the gaseous working medium M2. The device 1 comprises a working line AL, wherein the volume V enclosed by the working line AL is divided into at least two sections, namely a first section AL-V1 and a second section AL-V2. The first section AL-V1 is configured to receive a pressure transmission medium M1, and the second section AL-V2 is configured to receive and discharge the gaseous working medium M2. At least one inlet and outlet valve 2 is provided for receiving and discharging the gaseous working medium M2, wherein a first volume bounded by the first section AL-V1 is separated from a second volume bounded by the second section AL-V2 by a first separating layer T12 that is movable in the working line AL.

[0035] The first separating layer T12 is arranged such that pressure differences between the first AL-V1 and second section AL-V2 of the working line AL are compensated for by a displacement of the first separating layer T12 in the working line AL (the displacement is exemplified in Fig. 1 (indicated by arrows) and any resulting change in the size ratio between the first volume and the second volume is compensated for, whereby the working medium M2 can be compressed and thus heated.

[0036] Furthermore, the device 1 comprises a heat exchanger line WL for receiving the heat exchange medium M3. The heat exchanger line WL is coupled to the first section AL-V1 of the working line AL to achieve pressure equalization by connecting the heat exchanger line WL to the first section AL-V1 of the working line AL and by providing a second separating layer T13 between these lines (i.e., the working line AL and the heat exchanger line WL) to separate the lines from each other.

[0037] The second separating layer T13 is designed and arranged such that continuous pressure equalization is ensured between the heat exchanger line WL and the first section AL-V1 of the working line AL. The second section AL-V2 of the working line AL has a heat dissipation section AL-V2' (for clarity, this is only marked and labeled on one side of the x-axis symmetrical structure) which is enclosed on the outside and inside by a two-part heat absorption section WL' of the heat exchanger line WL, in that the working line AL has an inner wall AL-IW and an outer wall AL-AW enclosing the inner wall AL-IW (see also Fig. 2), and between the inner wall AL-IW and the outer wall AL-AW, a working medium gap S-M2 is formed for guiding the working medium M2. The inner wall AL-IW encloses a channel K through which a first part of the heat exchanger line WL is formed in the heat absorption section WL'. In addition, the heat exchanger line WL in the heat absorption section WL' also has a shell wall WL-M enclosing the outer wall AL-AW of the working line AL, through which a second part of the heat exchanger line WL is formed and bounded in the heat absorption section. Between the outer wall AL-AW of the working line AL and the shell wall WL-M of the heat exchanger line WL, a heat exchange medium gap S-M3 is formed, connected in parallel with the channel K, so that a heat exchange medium M3 guided in the heat absorption section WL' of the heat exchanger line WL can flow around the working line AL on the outside via the heat exchange medium gap S-M3 and on the inside via the channel K.

[0038] Furthermore, in Fig. 1 A pump 3 is shown, by means of which the pressure transmission medium M1 can be pressurized. If the pressure is increased, the interface T12 is moved towards the valves 2, and, in the case of closed valves, the working medium M2 is compressed and thus heated. After a predetermined time period and / or compression and successful heat transfer to the heat exchanger medium M3, the outlet valve 2 is opened, the pressure on the pressure transmission medium M1 is reduced, so that the interface 12 can move downwards again and fresh working medium M2 can flow into the second section AL-V2 via the inlet valve 2, which can subsequently be compressed and heated again by increasing the pressure. In the Fig. 1 The pump 3 shown, for example, is a hydraulic pump, in which hydraulic fluid 6 is shown being collected in a container 5.

[0039] The heat exchanger medium M3 can be, for example, a liquid medium, in particular water. Furthermore, the pressure transfer medium M1 in the first section AL-V1 of the working line AL can be an oil. Depending on the media used, the first separation layer T12 can be formed directly by the interface formed by the surface tension of the liquid pressure transfer medium M1 with respect to the gaseous working medium M2. Alternatively, the first separation layer T12 can be formed by a first separating agent T12 provided for this purpose, which is preferably designed as a spatially displaceable first sealing element.Similarly, the second separating layer T13 can be formed by a second separating agent provided for this purpose, which is preferably designed as a spatially displaceable second sealing element, either as an elastic membrane fixed at its edges or as a whole being spatially displaceable. The first separating layer T12 and / or the second separating layer T13 can also each be formed by the surface of a separating cylinder, which can be slidably held in the working line AL.

[0040] Furthermore, in Fig. 1 in conjunction with Fig. 2It is evident that the heat exchanger line WL is symmetrical about a longitudinal axis x in the area of ​​the heat absorption section WL'. More precisely, the working line AL in the heat emission section AL-V2' can be designed as a concentric double pipe, which is coaxial to the longitudinal axis x of the heat exchanger line WL in the area of ​​the heat absorption section WL', wherein the working medium gap S-M2 is formed between and bounded by the inner wall AL-IW and the outer wall AL-AW of the double pipe, wherein the outer wall WL-M of the heat exchanger line WL encloses the double pipe and the channel K is enclosed by the inner wall AL-IW of the double pipe (see also Fig. 2 Cooling fins projecting into channel K can be provided on the inner wall AL-IW to improve heat exchange. Fig. 2 Additional cooling fins are also shown, which protrude from the outer wall AL-AW into the heat exchanger medium gap S-M3 to improve heat exchange.

[0041] Unlike the figures shown, the inner wall AL-IW and the outer wall AL-AW can form a multi-toothed star in cross-section, which is in particular axially or point-symmetric, wherein the star formed by the outer wall AL-AW is preferably an enlargement of the star formed by the inner wall AL-IW.

[0042] In Fig. 1 It is also evident that the working line AL in a region of the heat dissipation section AL-V2' is designed such that the working medium gap S-M2 narrows towards the at least one inlet and outlet valve 2. This region is designated with the reference numeral S-M2v.

[0043] It can also be provided that the working line AL is distributed across parallel-connected branches, at least within the heat dissipation section WL' AL-V2'. The term "parallel-connected" means that the parallel-connected medium can mix again after the parallel connection.

[0044] In Fig. 1 Furthermore, a heat exchanger 4 is shown, which can be part of the device 1, wherein the heat exchanger line WL is connected to the heat exchanger 4 for the purpose of discharging heat.

[0045] The invention is not limited to the embodiments shown, but is defined by the entire scope of protection of the claims.

[0046] Any reference numerals in the claims are exemplary and serve only to make the claims easier to read, without limiting them.

Claims

1. Device (1) for transferring heat from a gaseous working medium (M2) to a heat exchanger medium (M3) by compressing the gaseous working medium (M2), the device (1) comprising: - a working line (AL), wherein the volume (V) enclosed by the working line (AL) is divided into at least two sections, namely a first section (AL-V1) and a second section (AL-V2), wherein the first section (AL-V1) is arranged to receive a pressure transfer medium (M1) and the second section (AL-V2) is arranged to receive and discharge the gaseous working medium (M2), wherein at least one inlet and outlet valve (2) is provided for receiving and discharging the gaseous working medium (M2), wherein a first volume bounded by the first section (AL-V1) is separated from a second volume bounded by the second section (AL-V2) by a first separating layer (T12) which is displaceable in the working line (AL), wherein the first separating layer (T12) is arranged in such a way that pressure differences between the first (AL-V1) and second section (AL-V2) of the working line (AL) are equalized by a displacement of the first separating layer (T12) in the working line (AL) and an associated change in the size ratio between the first volume and the second volume, and - a heat exchanger line (WL) for receiving the heat exchanger medium (M3), characterized in that the heat exchanger line (WL) is coupled to the first section (AL-V1) of the working line (AL) in order to bring about pressure equalization, in that the heat exchanger line (WL) is connected to the first section (AL-V1) of the working line (AL) and a second separating layer (T13) is provided between these lines (WL, AL), a second separating layer (T13) is provided for separating the lines (WL, AL) from one another, the second separating layer (T13) being designed and arranged in such a way that there is continuous pressure equalization between the heat exchanger line (WL) and the first section (AL-V1) of the working line (AL), wherein the second section (AL-V2) of the working line (AL) has a heat emission section (AL-V2') which is enclosed on the outside and inside by a two-part heat absorption section (WL') of the heat exchanger line (WL), in that the working line (AL) has an inner wall (AL-IW) and an outer wall (AL-AW) encasing the inner wall (AL-IW), and a working medium gap (S-M2) for guiding the working medium (M2) is formed between the inner wall (AL-IW) and the outer wall (AL-AW), the inner wall (AL-IW) enclosing a channel (K) through which a first part of the heat exchanger line (WL) is formed in the heat absorption section (WL'), and the heat exchanger line (WL) in the heat absorption section (WL') also has a jacket wall (WL-M) which surrounds the outer wall (AL-AW) of the working line (AL) and by which a second part of the heat exchanger line (WL) is formed and limited in the heat absorption section (WL'), wherein a heat exchanger medium gap (S-M3) connected in parallel with the channel (K) is formed between the outer wall (AL-AW) of the working line (AL) and the jacket wall (WL-M) of the heat exchanger line (WL), so that a heat exchanger medium (M3) guided in the heat absorption section (WL') of the heat exchanger line (WL) can flow around the working line (AL) on the outside via the heat exchanger medium gap (S-M3) and on the inside via the channel (K).

2. Device (1) according to claim 1, wherein the heat exchanger medium (M3) is at least partially gaseous.

3. Device (1) according to claim 1, wherein the heat exchanger medium (M3) is a liquid medium, in particular water.

4. Device (1) according to one of the preceding claims, wherein the pressure transfer medium (M1) in the first section (AL-V1) of the working line (AL) is an oil.

5. Device (1) according to claim 4, wherein the first separation layer (T12) is formed directly by the interface formed due to the surface tension of the liquid pressure transfer medium (M1) with respect to the gaseous working medium (M2).

6. Device (1) according to one of claims 1 to 4, wherein the first separating layer (T12) is formed by a first separating means provided for this purpose, which is preferably formed as a spatially displaceable first sealing element.

7. Device (1) according to one of the preceding claims, wherein the heat exchanger line (WL) is formed symmetrically about a longitudinal axis (x) in the region of the heat receiving section (WL').

8. Device (1) according to claim 7, wherein the working line (AL) in the heat release section (AL-V2') is formed as a concentric double tube which is formed coaxially to the longitudinal axis (x) of the heat exchanger line (WL) in the region of the heat absorption section (WL'), wherein the working medium gap (S-M2) is formed between the inner wall (AL-IW) and the outer wall (AL-AW) of the double pipe and is bounded by the latter, wherein the jacket wall (WL-M) of the heat exchanger line (WL) encloses the double pipe and the channel (K) is enclosed by the inner wall (AL-IW) of the double pipe.

9. Device according to one of the preceding claims, wherein the inner wall (AL-IW) and the outer wall (AL-AW) form a multi-toothed star in cross-section, which in particular is formed axially or point-symmetrically, wherein the star formed by the outer wall (AL-AW) is preferably an enlargement of the star formed by the inner wall (AL-IW).

10. Device (1) according to one of the preceding claims, wherein the working line (AL) is formed in a region of the heat release section (AL-V2') in such a way that the working medium gap (S-M2) tapers towards the at least one inlet and outlet valve (2).

11. Device (1) according to one of the preceding claims, wherein the working line (AL) is distributed at least within the heat release section on branches connected in parallel.

12. Device (1) according to one of the preceding claims, wherein the device (1) is designed for a nominal working pressure of between 6 bar and 1000 bar, preferably between 50 bar and 100 bar, in that the working line (AL) and the heat exchanger line (WL) as well as the at least one inlet and outlet valve (2) are designed to withstand the nominal working pressure.

13. Device (1) according to one of the preceding claims, wherein the device (1) further comprises a pump (3) for transmitting pressure to a pressure transmission medium (M1) contained in the first section (AL-V1) of the working line (AL), wherein the pump (3) is preferably designed as a rotary piston pump, piston pump, gear pump or vane pump.

14. Device (1) according to one of the preceding claims, wherein the device (1) further comprises a heat exchanger (4), wherein the heat exchanger line (WL) is connected to the heat exchanger (4) for releasing heat.

15. Device (1) according to one of the preceding claims, wherein the second separating layer (T13) is formed by a second separating means provided for this purpose, which is preferably designed as a spatially displaceable second sealing element, which is designed as an elastic membrane fixedly mounted at its edges or spatially displaceable in its entirety.