Fluid Reservoir With Heat Exchanger

Abstract

The invention relates to a fluid reservoir having a sorption medium. An energy absorbing and/or releasing device is provided for the improvement of the energy balance and for an immediately accessible heat supply from the sorption medium, for the gas release process, during the extraction of fuel from the fluid reservoir. For the intermediate storage of thus transferred energy in the form of differential heat between the filling and emptying of the fluid reservoir, the use of a latent heat reservoir, especially materials having melting temperatures of between 0° C. and 1400° C., is preferred. The use of such a latent heat reservoir enables permanent sufficient supplies of immediately accessible energy for a sufficient fluid extraction from the fluid reservoir, such that a flawless operation of an energy converter operated using the fluid, e.g. in the form of a fuel cell or a gas motor, is always ensured, especially in the event of low ambient temperatures.

Description

The present invention relates to a fluid reservoir, in particular a fluid reservoir with a sorption medium as generically defined by the preainble to claim 1.

PRIOR ART

For storing fluids, especially gaseous fuels for operating motor vehicles, the use of sorption reservoirs, for instance based on metal hydrides or metal organic frameworks (MOFs), is known. when the tank is being filled, so-called binding energy is released as heat and has to be removed. For removing the gas stored in the tank, this differential energy must be resupplied, however, so that the aforementioned bond between the gas and the sorption medium can be broken up again and to enable the gas to be released for removal.

For introducing this expenditure of energy for withdrawing the gas from the sorption tank, the provision of an electric heater or the utilization of waste heat from the engine is currently know

An electric heater increases the load on the battery, which is required for storing energy in reserve, or on a corresponding rechargeable battery that especially upon starting an engine can as a result be additionally heavily loaded. The release of the gas from the sorption reservoir by means of engine heat, in the starting mode of an engine, functions only unsatisfactorily to poorly, because of the comparatively low temperature of the engine. Especially at cold outdoor temperatures, it can be appreciated that such a procedure is unfavorable or even nonfictional.

OBJECT AND ADVANTAGES OF THE PRESENT INVENTION

It is therefore the object of the present invention to improve a fluid reservoir of the type discussed at the outset.

This object is attained by the characteristics of claim 1. Advantageous and expedient refinements are disclosed in the dependent claims.

Accordingly, the present invention relates to a fluid reservoir, in particular a fluid reservoir with a sorption medium, which distinguished in that an energy absorbing and/or emitting device is provided. Thus the binding energy that is liberated on refueling the sorption reservoir can be received in the reservoir and carried out of it via suitable additional components, such as a heating and/or cooling loop, or, for breaking up the bond again between at least some of the gas and the sorption medium for removal of gas from the tank, this energy can be resupplied to the tank at any time and be immediately available.

The following comments may be made about possible types of reservoirs and reservoir properties: For storing gaseous fuels in motor vehicles, sorption reservoirs based for instance on metal hydrides or metal organic frameworks (MOFs) may for instance be used. On filling the tank with the gas, the binding energy is released as heat and must be carried away. As a rule, in this process a certain temperature, which corresponds to the activation energy for desorption of the gas, must be exceeded.

In latent-heat reservoirs, by utilizing the heat of melting upon a change of phase of a suitable storage material, a high energy density can be attained at only a slight temperature rise. Because of the higher energy density, the reservoir can be designed more compactly than a conventional sensitive reservoir because of the small surface area and a low temperature of the reservoir, the heat losses of the reservoir are simultaneously reduced. For this purpose, materials for utilizing the latent heat for melting temperatures from 0 to 1400° C. are preferably proposed.

For the buffer storage of this thus-transferred energy in the form of the differential heat between refueling and emptying of the fluid reservoir the use of a latent-heat reservoir is therefore preferably proposed. By the use of such a latent-heat reservoir, enough available energy for adequate fluid removal from the sorption tank is constantly available, so that at any time, satisfactory operation of the energy converter operated with this fluid, for instance in the form of a fuel cell or a gas engine, especially at low ambient temperatures, is assured.

To achieve the best possible effect of the energy transfer both upon removal and upon resupply, it is furthermore proposed that some of the energy absorbing and/or emitting device is disposed in the interior of the fluid reservoir. This can be achieved for instance by means of a line that passes through a plurality of reservoir regions.

Such reservoir regions can be understood for instance to be three-dimensional regions, extending coaxially to one another in the interior of the reservoir, that are penetrated for instance by a bundle of pipes, which are preferably uniformly spaced apart, that extends longitudinally in the interior of the reservoir. However, an arrangement of a spiral bundle of pipes, for instance extending along a longitudinal axis, is also conceivable; for increasing the efficiency, it may also be disposed coaxially to one or more further, preferably identically oriented, bundles of pipes.

To increase the energy carrier throughput in the interior of this energy absorbing and/or emitting device, the use of a pump is furthermore proposed. The energy carrier medium may for instance be a correspondingly suitable fluid.

For reinforcement for the sake of even faster readiness for operation and/or as a redundant device, a heating element may furthermore be proposed, which serves to overcome at least some of the binding energy for the release of the fluid bound in the sorption medium. Such a heater may for instance be an electric heater, but it can also be attained by means of a connection to a heating and/or cooling loop of the energy converter to be operated, so that the waste heat thus to be carried away by the energy converter, as a result of this coupling to the converters heating and/or cooling loop, likewise reinforces the energy transfer in the energy absorbing and/or emitting device.

The thermal coupling between such a cooling loop, for instance an engine cooling loop or a fuel cell cooling loop, and the fluid reservoir can selectively be done with two separate cooling loops, but direct fluidic communication of the tube coolant or heating medium loops is also conceivable. With a separate construction, the heat transfer can be effected for instance through an additional heat exchanger. The use of valves is advantageous in both cases, since this makes a suitable loop control for various operating states possible.

As an alternative to this first combination, or in addition to it, heat recovery can also be provided by way of the exhaust gas output by the thermal and/or mechanical energy converter. For this purpose as well, a heat exchanger may be provided, which furnishes the residual heat, present in the exhaust line, as energy for re-releasing the gas stored in the sorption medium, preferably once again reinforced by a pump and connectable and disconnectable via valves.

EXEMPLARY EMBODIMENT

The present invention will be described in further detail below in conjunction with the accompanying drawing and the description thereof.

Show is:

FIG. 1, a schematic circuit diagram of a fluid reservoir, equipped with a sorption medium, with an integrated energy absorbing and/or emitting device and with plumbing interconnection with further functional components.

In detail, the illustration in FIG. 1 shows a fluid reservoir 1, filled with a sorption medium 2, and an energy absorbing and/or emitting device 3 integrated with it. Wit a heating and/or cooling loop 4, the binding energy liberated when the sorpution reservoir I is refueled with gas can be recovered and buffer-stored in a latent-heat reservoir 5 for later reintroduction in order to reverse the binding process.

Part of the energy absorbing and/or emitting device passes in the form of a line 6 in the form of a bundle of pipes 7 through a plurality of inner regions of the reservoir. As a result, the binding energy liberated in refueling can be carried away as well as possible, and for the case of re-removal of the gas from the tank, it can be resupplied with as uniform as possible a spatial distribution, so that a rapid gas release from the sorption medium is assured. To increase the efficiency of the energy absorbing and/or emitting device, the heat carrier medium introduced into the line 6, which may for instance be an antifreeze solution, can be made to circulate by means of a pump 8.

For reinforcement in the resupply of heat to the sorption reservoir, or as a redundant heat source, a heater 13 may be provided, which as an example is integrated here with the line 6 of the heating and/or cooling loop 4. To further optimize the energy balance, the energy absorbing and/or emitting device 3 may communicate with a heating and/or cooling loop 15 of a thermal and/or mechanical energy converter 16. This communication is represented symbolically here by the connection 14, which for introducing fluid includes a valve 9 in the form of a control valve. The introduction of heat from the engine coolant loop is effected via a heat exchanger 17.

Additional operating states of the fluid reservoir 1 are possible by means of suitable triggering of the other valves 10, 11 and 12. For instance, a further heat input into the energy absorbing and/or emitting device 3 is possible by way of introducing the exhaust gas heat, removed in an exhaust line 20 and recovered via a heat exchanger 18, of the energy converter 16 via the line connection 19. The supply of fuel to the energy converter 16, for instance in the form of a gas engine or fuel cell, is effected, under the control of the two valves 22 and 23, via the fluid line 21.

Thus by means of the energy absorbing and/or emitting device 3 provided according to the invention, with the heating and/or cooling loop 4 and the latent-heat reservoir 5, a possibility is described for optimizing the energy balance while simultaneously improving the readiness for operation of a sorption mediun-equipped fluid reservoir 1 by means of one possible, but not limiting, exemplary embodiment.

Claims

1-10. (canceled)

11. A fluid reservoir, in particular a fluid reservoir with a sorption medium, provided with an energy absorbing and/or emitting device.

12. The fluid reservoir as defined by claim 11, wherein the energy absorbing and/or emitting device has a heating and/or cooling loop.

13. The fluid reservoir as defined by claim 11, wherein the energy absorbing and/or emitting device has a latent-heat reservoir.

14. The fluid reservoir as defined by claim 12, wherein the energy absorbing and/or emitting device has a latent-heat reservoir.

15. The fluid reservoir as defined by claim 11, wherein part of the energy absorbing and/or emitting device is disposed in the interior of the fluid reservoir.

16. The fluid reservoir as defined by claim 12, wherein part of the energy absorbing and/or emitting device is disposed in the interior of the fluid reservoir.

17. The fluid reservoir as defined by claim 14, wherein part of the energy absorbing and/or emitting device is disposed in the interior of the fluid reservoir.

18. The fluid reservoir as defined by claim 11, wherein the energy absorbing and/or emitting device has a line that passes through a plurality of inner regions of the reservoir.

19. The fluid reservoir as defined by claim 12, wherein the energy absorbing and/or emitting device has a line that passes through a plurality of inner regions of the reservoir.

20. The fluid reservoir as defined by claim 17, wherein the energy absorbing and/or emitting device has a line that passes through a plurality of inner regions of the reservoir.

21. The fluid reservoir as defined by claim 11, wherein the energy absorbing and/or emitting device includes a bundle of pipes.

22. The fluid reservoir as defined by claim 20, wherein the energy absorbing and/or emitting device includes a bundle of pipes.

23. The fluid reservoir as defined by claim 11, wherein the energy absorbing and/or emitting device includes a pump.

24. The fluid reservoir as defined by claim 22, wherein the energy absorbing and/or emitting device includes a pump.

25. The fluid reservoir as defined by claim 11, wherein the energy absorbing and/or emitting device has a heating element.

26. The fluid reservoir as defined by claim 24, wherein the energy absorbing and/or emitting device has a heating element.

27. The fluid reservoir as defined by claim 11, wherein the energy absorbing and/or emitting device has a connection to a heating and/or cooling loop of a thermal and/or mechanical energy converter.

28. The fluid reservoir as defined by claim 26, wherein the energy absorbing and/or emitting device has a connection to a heating and/or cooling loop of a thermal and/or mechanical energy converter.

29. The fluid reservoir as defined by claim 11, wherein the energy absorbing and/or emitting device has a connection to an exhaust line of a thermal and/or mechanical energy converter.

30. The fluid reservoir as defined by claim 28, wherein the energy absorbing and/or emitting device has a connection to an exhaust line of the thermal and/or mechanical energy converter.