Energy / buffer storage unit for heating and / or cooling

Abstract

The present invention discloses a buffer storage unit for heating and / or cooling a medium (in particular water), such as, for example, an electrical water heater and / or cooler, comprising a phase change material (1), a vessel serving as a storage device for the medium which is thermally connected to the phase change material (1), wherein the phase change of the phase change material (1) can be used to heat and / or cool the medium in the storage device.

Description

[0001] Energy / buffer storage unit for heating and / or cooling

[0002] TECHNICAL FIELD

[0003] The present invention relates to an energy / buffer storage unit for heating and / or cooling a medium such as, for example, an electrical water heater and / or cooler that can be used in any area of use such as, for example, buildings and / or vehicles such as, for example, commercial and / or military aircraft where equipment can be activated, for example, by a passenger and / or a crew member.

[0004] Such an energy / buffer storage unit for heating and / or cooling can be used, for example, for cabin equipment and / or devices in vehicles such as, for example, an aircraft, such as, for example hot and / or cold water supply, for example in a lavatory or a galley.

[0005] BACKGROUND ART

[0006] For example, an aircraft cabin hosts several individual equipment and / or individual devices which can be triggered and activated by passengers and / or by crew members. Such equipment and / or devices may generally be composed of at least one sensor, which is either a mechanical or an electrical sensor and which triggers an actuator for activating the functionalities of each individual equipment and / or each individual device.

[0007] Such equipment and / or devices might for example include a water faucet, such as those found in restrooms.

[0008] Such equipment and / or devices require power to be used where said power is generated.

[0009] One example of such an equipment and / or device is a water heater. Water heaters that currently exist in the prior art heat a water content inside and deliver heated water to a device such as, for example, a mixing device. The heat to be stored depends on the specific heat capacity of water. The consumption parameters, heat and flow and the heat capacity of the water heater, determine the size and electrical power and the necessary water heater size limits the installation at a variety of places, for example, just under the sink.

[0010] The thermodynamic design of such water heater comprises of the water vessel with a specific water volume, a heat wire and an electronic control unit with connected different temperature sensors to control the power supply to the heat wire which is located inside the filled water volume of the heater.

[0011] PROBLEMS ASSOCIATED WITH THE PRIOR ART

[0012] Water heaters in the prior art utilize the sensible heat of the heated water volume plus portions of the water heater in one physical state with a limited amount of heat capacity, resulting in a high power demand and system weight.

[0013] Conventional water heaters generally heat water in an internal cavity where heat stored is determined by the specific heat capacity of water. The size and electrical power requirements are generally determined by consumption parameters. The required size of the water heater typically restricts installation to typically just beneath a sink where ample open spaces are available.

[0014] TECHNICAL OBJECTIVES OF THE INVENTION

[0015] It is the objective of the present invention to reduce the power demand and the system weight of a heating or cooling system for a medium by using the latent heat of a suitable phase change material leading to a significantly increased heat capacity of the system.

[0016] TECHNICAL SOLUTION

[0017] This objective is achieved by a system according independent claim 1. The dependent claims relate to advantageous embodiments.

[0018] SUMMARY AS WELL AS TECHNICAL SOLUTIONS AND ADVANTAGEOUS

[0019] EFFECTS OF THE INVENTION

[0020] The energy / buffer storage unit for heating and / or cooling of the present invention has several advantages over the existing prior art devices, such a higher heat density, smaller dimension, less restrictions and reduced power requirements.

[0021] An energy / buffer storage unit for heating and / or cooling according to the present invention is capable of solving the above objectives with the described technical features disclosed within these application documents. The energy / buffer storage unit for heating and / or cooling can be used in any kind of static or moving environment or entity as further described below.

[0022] Such an environment or entity will be described as area of use throughout this application.

[0023] The energy / buffer storage unit for heating and / or cooling can be used in any area of use such as vehicles such as transport vehicles such as, for example, aircraft, trains, busses, trucks, ships or cars, more particularly, passenger transport vehicles for passenger transportation such as, for example, passenger aircraft, passenger trains, passenger busses, passenger trucks, passenger ships or passenger cars, even more particularly, respective lavatories, cabins, passenger and / or crew rest compartments, galleys and / or kitchenettes on said passenger transport vehicles such as, for example, a lavatory, a cabin and / or a galley of an aircraft, a lavatory, a cabin, a galley and / or a kitchenette of a train, a lavatory, a cabin, a galley and / or a kitchenette on a bus, a lavatory, a cabin, a galley and / or a kitchenette on a truck, a lavatory, a cabin, a galley and / or a kitchenette on a ship or lavatory, a cabin, a galley and / or a kitchenette of a RV (recreational vehicle).

[0024] The energy / buffer storage unit for heating and / or cooling can also be used in any area of use such as buildings, houses, flats or immobile installations, such as a lavatory, a cabin, a galley and / or a kitchenette thereof.

[0025] Examples for a device or equipment encompass touchless, pushbutton, mechanical, electromechanical faucets or water dispensers in a lavatory or galley compartment, with a location in the aircraft cabin.

[0026] The terms “device” and “equipment” are employed interchangeably, their meaning, however, is understood in the conventional understanding of each word and should not be considered as synonyms.

[0027] This energy / buffer storage unit for heating and / or cooling of the present invention is intended to be capable to be integrated, for example, in the locations mentioned above such as, for example, any cabin area of commercial and / or military aircraft.

[0028] Examples of the equipment and / or devices could be operation of a water faucet in a lavatory, or a galley but the present invention is not limited thereto and relates to any equipment and / or device within the locations mentioned above. By implementing the present invention, the following aspects can be improved:

[0029] Water heating and / or cooling possibility, for example, in a lavatory and / or a galley.

[0030] Heating and / or cooling of vehicle inserts such as galley inserts such as ovens, water boilers, coffee maker, etc.

[0031] The invention utilizes the physical effect of greater heat capacity during a phase transition. Such a phase transition can be, for example, from liquid to solid, from liquid to gas, from solid to solid, from liquid to liquid or from solid to gas. This physical phenomenon allows, for example, a water heater to be made smaller than current water heater with significantly lower power demands. Heating or cooling devices for chiller, oven and coffee maker can be realized without overpressure design concepts. Thus, a huge variety of new designs are possible, which can be adapted to all kinds of spaces and areas to fit such an energy / buffer storage unit for heating and / or cooling of the present invention. One very simple example could be a rectangular shape, for example.

[0032] The present invention is an energy / buffer storage unit for heating and / or cooling such as, for example, an instantaneous water heater. The electrically generated heat is stored as latent heat in a special medium. The heat storage in a latent storage tank is many times greater than in water. The reduction of the water heater size allows the installation in areas other than, for example, under the sink and the use in other areas compared to the prior art.

[0033] PCMs (phase change materials) are materials that can be technically used during their phase change by means of collecting their heat. In one preferred embodiment, phase change materials with a solid-to-liquid phase change are used.

[0034] The energy storage during a phase change as in the present invention shows up higher energy values than the specific heat capacity during regular heating of a given material such as water as utilized in the prior art. For those reasons, there is an advantage with respect to the energy storage density, especially for small temperature differences. The specific heat which occurs during regular heating is also called sensible heat and is associated with a temperature rise. This is not the case for latent (hidden) heat where the temperature remains the same during the phase transition.

[0035] Therefore, it is possible to use lower temperatures during use when heating is achieved compared to the heater systems of the available prior art.

[0036] Further, it is possible to use higher temperatures during use when cooling is achieved compared to the cooling systems of the available prior art.

[0037] With the use of phase change materials (PCM) it is possible to design a heat accumulator that stores electrical energy transformed into heat energy in a small space, which is reduced in comparison to such units in the prior art. The PCM can store several times the heat with the same volume, for example about three times the heat energy of water. It is equally possible to use the present invention with the process of cooling. A huge variety of applications exist and are possible with the features of the present invention.

[0038] For example, the present invention could be implemented as a water heater: Within the present invention the heat storage volume for heat peak load can be severely reduced. In one specific example, water heater power can be reduced from 400 W to 210 W. Therefore, in the present invention, heat storage volume for heat peak load is reduced. This is the challenge for a universal equipment for all platforms, which can be successfully achieved by the present invention.

[0039] In addition, the PCM Water Heater differs essentially from today's water heater in its external contours.

[0040] The PCM module can take on any shape, since the PCM module can be designed into a water pressure vessel. The PCM Heater can, for example, be designed to be flat and / or planar, so it could, for example, be installed behind a feature, such as, for example, a mirror, for example, in a lavatory.

[0041] The current Water Heater in the prior art has a necessary storage volume, for example, of 800 cm3. The PCM Heater of the present invention can have a far reduced storage volume due to the far increased heat storage capacity. The heat storage capacity of the present invention can be, for example, about 3 times the heat storage capacity of the prior art, which means that the construction volume of the present invention can be correspondingly smaller.

[0042] The present invention could be used for passive cold and / or hot temperatures for transport in transport vehicles, such as, for example, trolleys.

[0043] The advantage of PCM materials can be particularly realized for small temperature variations (delta T), e.g. 40°C - 50°C for water heating or -5°C - 0°C for water cooling or 6°C - 7°C for Champagne storage and service. The direct comparison with water at different temperature differences illustrates high storage density for small temperature variations.

[0044] Whenever it is needed, the PCM can be applied in all situations such as for heat and / or cold storage, for an increase in the heat capacity of a system, for adjustment of temperature variations, for heat recovery and temperature stabilization.

[0045] An exemplary PCM Heater could include one or more of the following features:

[0046] - Electrically heatable latent heat storage.

[0047] Chemical or physical heat storage.

[0048] - Heating element covers completely with the phase change material, regardless of an aggregate state.

[0049] The heat exchanger is embedded from the PCM.

[0050] - Water runs through heat exchanger.

[0051] There is no water contact to the PCM.

[0052] - Heating element is adapted to heat transfer characteristics.

[0053] - Water heater with a latent heat storage tank for heating potable water.

[0054] The invention aims to optimize the size, power consumption, weight and shape of an energy / buffer storage unit for heating and / or cooling.

[0055] The water heater of the present invention uses PCMs to reduce the water heater size and the needed power supply with unchanged heating performance. PCMs (phase change materials) are materials that can be technically used during their phase change by means of collecting their heat. In a preferred embodiment, the solid-to-liquid phase change is used. For technical reasons, the solid-to-liquid phase change can be better achieved than the liquid-to-gas change.

[0056] The invention is more sustainable than the existing water heater of the prior art. In comparison to conventional energy / buffer storage units for heating and / or cooling, in an energy / buffer storage unit according to the invention, dimensions and power consumption will be smaller while showing the same performance. A power reduction of 50% and a component weight reduction of 15% are feasible.

[0057] This invention can be applied to commercial aircraft lavatories and galleys.

[0058] DESCRIPTION OF THE DRAWINGS

[0059] Fig- 1 shows a comparison of the sensible heat and the latent heat in an exemplary solid-liquid phase diagram.

[0060] Fig- 2 (a) shows an example of a prior art heat vessel in its circular configuration.

[0061] Fig- 2 (b) shows an exemplary embodiment of the present invention comprising a PCM.

[0062] DETAILED DESCRIPTION OF THE DRAWINGS

[0063] Fig. 1 shows a comparison of the sensible heat and the latent heat in an exemplary solid-liquid phase diagram. "Sensible heat" refers to the heat exchanged by a system or object that leads to a change in its temperature without a phase change (such as melting or boiling). It's contrasted with "latent heat," which is the “hidden” heat absorbed or released during a phase change at constant temperature. “Sensible heat” specifically refers to heat that can be sensed or measured by a thermometer as the amount of heat captured or released is directly proportional to the decrease or increase of temperature. In contrast thereto, release or capture of “latent heat” during a phase transition occurs at constant temperature and cannot be sensed or measured by a thermometer. If substances with high specific latent heat per volume unit are used in an energy / buffer storage unit according to the invention, they can store or release very large amounts of energy (heat) per unit volume and rapidly release or store latent (“hidden”) heat during a phase transition. This favorably contrasts with conventional energy / buffer storage units which rely on the storage or release of sensible heat.

[0064] Fig. 2 (a) shows a typical conventional electric heater for electrically heating a liquid, such as e.g. water, i.e. a typical conventional water boiler 3 for providing hot water in any of the examples given above, such as for example, for cabin equipment and / or devices in vehicles such as, for example, an aircraft, such as, for example hot and / or cold water supply, for example in a lavatory or a galley. Typical overall dimensions are on the order of e.g. 10 cm times 24 cm for storing hot water:

[0065] Fig. 2 (b) shows a buffer storage unit for heating and / or cooling according to an embodiment of the present invention comprising a phase change material (PCM). In this specific embodiment the PCM is arranged in the form of a slab 1 over which a conduit (meandering pipe 2) is mounted. This meandering pipe 2 is used to guide a liquid to be heated, in particular water, from the lower end (inlet 2a) shown in Fig. 2(b) to the upper end (outlet 2b) shown in Fig. 2(b). When a phase change occurs in the PCM slab 1, the “hidden” latent heat is rapidly released and warms the water flowing through the conduit 2 and over the surface of the PCM slab 1. This provides a very efficient method for transferring heat to the water running through the meandering pipe 2. However, the geometric form of the phase change material (PCM) shown as a slab in Fig, 2(b) is only one of a large variety of possible geometries. Instead of a slab, the PCM module may in principle be formed in any arbitrary geometric form that can be tailor shaped in accordance with a specific mounting situation. The PCM module can, for example, be designed to be flat and / or planar, so that it could, for example, be installed behind a feature, such as, for example, a mirror, for example, in a lavatory. For example, a PCM module to be used for heating water in a lavatory in an airplane could be custom shaped to fit cavities or recesses in an aircraft lavatory as best as possible, as a very compact installation is required to make the best use of the limited space available in such an environment. Furthermore, instead of a meandering pipe mounted on an exterior surface of a PCM slab other means for ensuring heat transfer from the PCM volume in which a phase transition occurs to a medium to be heated or cooled could be realized as long as a storage device of any shape with a vessel thermally connected to the phase change material is provided, wherein the phase change of the phase change material can be used to heat and / or cool a medium (such as for example, but not limited to) water in the storage device.

[0066] ALTERNATIVE EMBODIMENTS

[0067] This invention describes a solution for a thermal heat management system in an aircraft, but similar areas of use as stated above could be used for various equipment and / or for various devices.

[0068] INDUSTRIAL APPLICABILITY

[0069] This invention can be applied, for example, in vehicles such as, for example, commercial and / or military aircraft. The present invention can be used in any areas of commercial or military aircraft where equipment and / or devices can be activated by passengers and / or crew members.

[0070] LIST OF REFERENCE NUMERALS

[0071] 1 PCM Phase change material

[0072] 2 conduit (meandering pipe) 2a inlet

[0073] 2b outlet

[0074] 3 conventional water boiler

Claims

CLAIMS1. A buffer storage unit for heating and / or cooling a medium such as, for example, an electrical water heater and / or cooler for heating or cooling water, said buffer storage unit comprising a PCM phase change material (1), a storage device of any shape with a vessel thermally connected to the phase change material, wherein the phase change of the phase change material can be used to heat and / or cool a medium in the storage device.

2. The buffer storage unit for heating and / or cooling of claim 1 comprising a vessel, which can be pressurized.

3. The buffer storage unit for heating and / or cooling of claim 1 or 2, wherein the buffer storage unit for heating and / or cooling is portable and can be used, for example, in an aircraft trolley.

4. The buffer storage unit for heating and / or cooling of claim 1, 2 or 3, wherein the buffer storage unit for heating and / or cooling is used for hot water supply, for example, for use in a lavatory.

5. The buffer storage unit for heating and / or cooling of claim 4, wherein the hot water supply is configured to be installed at tiny locations, for example, behind a mirror, underneath a washstand, below a faucet and so on in a lavatory or galley.

6. The buffer storage unit for heating and / or cooling of claim 1, 2, 3, 4 or 5, wherein the PCM is a material where the phase change is a transition between liquid and solid and vice versa.

7. The buffer storage unit for heating and / or cooling of claim 1, 2, 3, 4 or 5, wherein the PCM is a material where the phase change is a transition between liquid and gas and vice versa.

8. The buffer storage unit for heating and / or cooling of claim 1, 2, 3, 4 or 5, wherein the PCM is a material where the phase change is a transition between solid and solid.

9. The buffer storage unit for heating and / or cooling of claims 1 to 8, wherein the phase change material has a volume of greater or equal 10 cm3.

10. The buffer storage unit for heating and / or cooling of claims 1 to 8, wherein a liquid is heated and / or cooled.

11. The buffer storage unit for heating and / or cooling of claims 1 to 9, wherein food is heated and / or cooled in a heating or cooling device.

12. The buffer storage unit for heating and / or cooling of claims 1 to 11, where the PCM material is selected from the following materials comprising of mainly salt hydrates, various paraffin mixes, natriumacetate-trihydratine based PCM and different PCM mixtures.

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