SK81594A3 - Heat accumulator of motor vehicle - Google Patents

Abstract

The gaps between the cells are 1 to 3 mm wide, the cells themselves being 5 to 8 mm thick, with smooth external surfaces. The minimum storage capacity of the packet of cells is 400 watt-hours at a storage temperature of at least 70 deg.C. Each grating comprises parallel members (9) bearing against the cells and running in the flow direction and transverse ones (10) of smaller cross-section generating turbulence in the water flowing round them. Gap width and cell thickness are such that heat discharge is at least 100 watt-hours per minute. The lengthwise members accommodate cell volume alterations without affecting turbulence generated.

Description

Motor vehicle heat accumulator

Technical field

The invention relates to a motor vehicle heat accumulator with an inner container, an outer container and a heat-insulating space between the inner container and the outer container, wherein a bundle of flat sheet metal latent heat storage cells having a rectangular plan view and between individual storage cells is arranged in the inner container.

In the case of latent heat, spacing interstices are formed by spacing intermediate spaces, flowing in the operational state by cooling water as the heat transfer medium, and a heat storage medium is arranged in the latent heat storage cells.

BACKGROUND OF THE INVENTION Motor vehicle heat in various embodiments and their function is to store the heat of the described construction to a large extent during the operation of the water so that the stored heat of the vehicle can be operated, especially during the seasons.

Precisely, the practical operation would be a large accumulation and which would have heat from the accumulation of short periods of time released heat and, in order to be able to require heating, of amounts of heat. It was possible to ensure the heat of the motor vehicle desirable to be released in the very water it could transport where needed,

Accumulators are known to prove the vehicle absorbs coolant when placing motor cold areas or passing through a motor vehicle, the need to consider depends on the capacity in the battery small volume, taking latent heat intervals to keep cooling in a very short time there, latent storage cells heat in a very short time to their full storage capacity. As latent heat storage cells are meant heat storage cells which use a phase change of the heat storage medium to fill and release heat. All this leads to a physically complex problem circuit, which is additionally burdened by production-boundary technical conditions if the heat accumulators of a motor vehicle are to be produced in as flexible as possible automatic production, in large quantities, with high accuracy and to satisfy all requirements .

SUMMARY OF THE INVENTION

The invention is based on the described complex problem circuit and solves it very simply.

After solving this problem circuit, the present invention provides a motor vehicle heat accumulator with an inner vessel, an outer vessel, and a heat insulating space between the inner vessel and the outer vessel, wherein a bundle of flat sheet metal latent heat storage cells having a rectangular sheet is arranged in the inner vessel. the plan view and between the latent heat storage cells are formed by spacing gratings of the interstices, flowing in the operating state by cooling water as the heat transfer medium, wherein the latent heat storage cells provide a thermal storage medium, and according to the invention in that the spacing intermediate spaces have a gap thickness in the range of 1 to mm.

however, latent heat storage cells have a cell thickness in the region of 5 mm to S mm and have a smooth outer surface but with a low surface roughness on the outside, latent heat storage cells have a storage capacity of at least 400 watths at an accumulation temperature of at least 70 ° C and, nevertheless, the spacing lattices of the gaps have latent heat storage cells seated in the grating elements which are arranged in the direction of the cooling water flow, and the free lattice elements treated therebetween, and the gap thicknesses and cell thicknesses are aligned with each other such that The heat release is the release temperature at a release rate of at least

100 watts / hour

n., wherein the free lattice elements are arranged such that a turbulent flow is generated on the free lattice elements at latent heat storage cells at latent heat storage cells compensated for latent cell volume changes at a cooling water flow rate corresponding to the release temperature storage rate. of heat resulting from the phase change of the storage medium without limiting the formation of turbulence on the free lattice elements. Preferably, the latent heat storage cells have a cell thickness of greater than 6 mm. Preferably, the release rate has a value in the range between 100 to 150 watts / min, for example 125 watts / min.

In an advantageous embodiment, the arrangement is designed such that, upon release, at least 50% of the stored heat is transferred to the cooling water in two minutes. It goes without saying that this applies to the maximum heat accumulated. Within the scope of the invention, it is possible to work with a variety of heat storage media that operate in the temperature regions given by the cooling water temperature by means of a phase transformation as set forth in claim 1, preferably as set forth in claims 1 and 2. heat as a storage medium of barium hydroxide eight-hydrate or a mixture thereof based on barium hydroxide eight-hydrate.

The invention is based on the finding that the release of heat from the latent heat accumulator over a short period of time is not dependent only on the refraction, that the storage capacity is adapted to the amount of coolant flow that flows through the latent heat accumulator during the heat release process. It is much more important to properly create hydrodynamic phenomena in relation to the flow of coolant in the vehicle's heat accumulator, the change in the storage medium phase, and the passage of the heat released by the phase change in the latent heat storage cell. According to the invention, this is achieved by combining the first three features of the characterizing part of claim 1, which in themselves depend on the storage capacity and the thermodynamic potentials of the various heat passages. The cell thickness and hence the volume of the storage medium in the individual latent heat storage cells are selected so that the number of heat storage cells in the motor vehicle heat accumulator is kept to a minimum, but to ensure that the heat released is released fast enough to get latent heat accumulators onto the surface of the heat storage cells and pass them on to the cooling water. Accordingly, a cell thickness according to the second aspect of the feature part of the main claim is provided. In addition, however, a sufficiently large volume flow of cooling water must also flow through the intermediate spaces. Therefore, the gap thickness in accordance with the first feature of the feature part of the main claim must not be too small. In order to ensure a positive turbulent flow of the flowing water in the spaced intermediate spaces, however, the free elements of the lattice are designed according to Karman as sources of turbulence on which Karman's swirl paths arise. Due to the hydrodynamics, the turbulent flow must be maintained during the phase transition, as the turbulent flow at a substantially smooth surface area of the latent heat storage cells substantially improves the heat transfer from the latent heat storage cells to cooling water and vice versa releases phase transformation heat that must be paid. It is further preferred that the heat transfer cannot be adversely affected by the formation of disturbing bands in the cooling water in the area of the latent heat storage cell surface areas. The surface area of the latent heat storage cells is so smooth that a uniformly adhering layer of cooling water which does not adversely affect the heat transfer cannot be formed thereon. The phase change results in changes in the volume of the storage medium and thus also of the latent heat storage cells.

which, as a rule, have a value of 10%, must not adversely affect the cooling water turbulence flowing through the gap gratings. This would occur if the lattice elements 1 were also released from the surface areas of the latent heat storage cells, and as a result part of the cooling water stream could flow around the free lattice elements formed as a source of turbulence.

According to the invention, all these facts are achieved in combination with other features and in combination with the fourth feature of the characterizing portion of the main claim. The necessary tuning will be carried out by the person skilled in the art on the basis of the facts of the invention in the laboratory without any difficulties. Surprisingly, the power of the cooling pump, which is usually installed in the cooling circuit of a motor vehicle, is sufficient to reliably overcome such pressure losses as are typically caused by the heat accumulator of the motor vehicle of the invention.

In detail, many possibilities are provided within the scope of the invention for a further embodiment and arrangement of the heat accumulator of a motor vehicle according to the invention. Thus, for example, latent heat storage cells are preferably arranged substantially horizontally in the inner vessel. The latent heat storage cells preferably consist of a thin copper sheet that monitors the deformation resulting from the phase change without problems. For a conventional passenger car with a larger or smaller but usual power, it has proven useful to adjust the numerical parameters to suit claims 6 to 10. It follows from the foregoing that the cooling water flow behavior in the spaces of the gap gratings is of particular importance. It is therefore recommended in this context that the free grid elements be designed and arranged so that a spectrum of homogeneous isotropic turbulence is formed in the coolant. This means that in accordance with the Karman vortex paths, the vortex curves formed on the free grid elements have identical diameters, which in the diameter of the cooling water flow diminish and energy ripen in their diameter, but are always re-formed on the free grid elements, so statistical distribution is constant. Preferably, the arrangement is further designed so.

3. The method according to claim 1, characterized in that the free grid elements and the grid bearing elements have rounded cross-sections and / or a rectangular cross-section with rounded corners and intersecting corners between the free elemental grids and between the abutting elements. This ensures that the coolant flow does not create pockets, more precisely dead water areas, in the spaced intermediate spaces that would interfere with heat transfer.

Overview of the figures in the drawing

The invention is explained in more detail below by way of example with reference to the drawing.

In FIG. 1 shows a longitudinal section through a heat accumulator of a motor vehicle according to the invention in parallel and with latent heat storage cells. In FIG. 2 is a section along line A - A through the object of FIG. 1. FIG. 3 with respect to FIG. 2, to a much larger extent, cut-out B of the object of FIG. 2. FIG. 4 is a plan view of the spacer grid of the engine heat accumulator

FIG. 1. On the Fig. 5 is a graphical representation that explains

thermodynamic relationships in the heat accumulator of a motor vehicle according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The heat accumulator of the motor vehicle shown is a latent heat accumulator and has an inner vessel 1, an outer vessel 2 and a heat insulating space 3 between the inner vessel 1 and the outer vessel 2. It is understood that the inner vessel 1 is mechanically fixed in the outer vessel 2. This is not shown in detail. The thermal insulation may be a vacuum thermal insulation. By comparing FIG. 1 to 3, it is evident that a bundle of latent heat storage cells 4 having a rectangular plan, flat and formed of a thin sheet is arranged in the inner vessel 1, with spacers formed between the latent heat storage cells between the lattice gaps. In connection with this fact, reference is also made to FIG. 4th

In the operational state, the spacer intermediate spaces 6 are flowed through cooling water as the heat carrier. In the latent heat storage cells 4, a heat storage medium is stored. The spacing between the light spaces 6 have a gap thickness 7 as set forth in the claims 1 and

The latent heat storage cells have a cell thickness as set forth in the claims 1

They have a smooth surface on the outside with as little roughness as possible. The latent heat storage cell stack 4 must have sufficient storage capacity.

This should be at least 400 watth-hours at an accumulation temperature of 70 ° C. By comparing FIG. 3 and 4 it can be seen that the lattice elements 9 and the spacing lattice 5 that abut the latent heat storage cells 4 are arranged in the direction of cooling water flow, and free lattice elements 10 are arranged across them.

Other special arrangements Special arrangements or mutual harmonization. The gap thickness 7 and the cell thickness 8 are matched to one another such that the latent heat accumulator is released from the storage temperature at a release rate of less than 100 watts / min, the free lattice elements being arranged such that at the flow velocity resulting from the velocity In the cooling water on the free lattice elements 10, a turbulent flow occurs, wherein the lattice elements 9, which abut the latent heat storage cells 4, capture and equalize the volumetric changes of latent heat storage cells 4 resulting from the phase change of the storage medium. it will ensure that the formation of turbulence on the free elements 10 of the grid is not adversely affected. Advantageously, the design is such that, upon release, at least%

accumulated amount of heat for cooling water.

In an exemplary embodiment of a motor vehicle heat accumulator, it may be an embodiment in which latent heat storage cells have barium hydroxide eight-hydrate or a barium hydroxide osmate hydrate mixture thereof as the storage medium.

In an exemplary embodiment and in accordance with a preferred embodiment of the invention, the latent heat storage cells 4 are arranged in the inner vessel 7 substantially horizontally. They may be formed of a thin copper sheet having a thickness as set forth in claim 6. It is possible to achieve a release rate of at least 120 watts / min.

As already mentioned, the free grid elements 10 are designed as sources of turbulence.

Due to the symmetry that is evident from the figures, it is possible to achieve a spectrum of homogeneous isotropic turbulence in the coolant, whose turbulence circles again, at the same time, arise as Karman vortex paths on the free elements 10 of the grid.

This is particularly advantageous for heat transfer. The free lattice elements 10, as well as the adjacent lattice elements 9, have a circular or round cross-section.

or, as shown, rectangular cross-sections with rounded corners. The intersecting corners between the free elemental gratings 10 and the abutting elemental gratings 9 have a rounding 11 so as to prevent the formation of dead water areas which adversely affect the heat transfer.

The thermodynamics of the relationships is explained in FIG. 5. where one example is shown. The first axis shows the time in linear spacing. The length of the first axis could correspond to a time interval of 25 minutes. Temperature is also plotted linearly on the second axis. The length of this second axis may correspond to 100 ° C. Overall, the graphic depicts the behavior of the heat accumulator of a motor vehicle according to the invention in the period between filling and releasing. The fully represented curve shows the temperature of the hot water supplied. The dashed line up to S shows the filling of the vehicle's heat accumulator in Watt hours. At point S, a charge of about 600 watts-hours was reached and the storage capacity is depleted. The heat accumulator of the motor vehicle consumed the corresponding amount of heat from the hot water supplied. The dotted curve indicates the temperature of the water that enters when the motor heat accumulator is released. It increases rapidly from its inlet temperature when the release is activated and then slower down to the temperature of the accumulated amount of heat, which is practically identical to the temperature of the hot water supplied to heat the accumulator. The whole area is a phase transformation in the vehicle's heat accumulator. The temperature of the water exiting from the heat accumulator of the motor vehicle then drops very rapidly. The curve shown in dotted lines should be considered inverse at the same time in this release. After the phase change, the remaining amount of residual heat, as well as the temperature of the water leaving the heat accumulator of the motor vehicle, drops sharply after the phase change.

P1 /

PAT E N T 0 V E N O R 0 K Y 1. Accumulator heat engine vehicles with inside container, with external container and with heat insulation space between the inner container and outer container while in

Claims (9)

P1 / PAT E N T 0 V E N O R 0 K Y 1. Accumulator heat engine vehicles with inside container, with external container and with heat insulation space between the inner container and outer container while in In the inner vessel, a stack of thin sheet metal latent heat storage cells having a rectangular plan is formed and between the latent heat storage cells spaced interstices are formed by spacing lattice gaps, flowing in the operating state through cooling water as the heat transfer medium, A heat storage medium is provided, characterized in that the spacing intermediate spaces (6) of the thickness (7) have gaps in the region of 1 to 3 mm, but the latent heat storage cells (4) have a cell thickness (8) of 5 mm. up to 8 mm and have a smooth surface area with little roughness on the outside, but a latent heat storage cell stack (4) has a storage capacity of at least 400 watths at a storage temperature of 70 ° C, and spacing gratings (5) of gaps to akumula latent heat cells (4) of lattice elements (9), which are arranged in the direction of cooling water flow, and free lattice elements (10) arranged therebetween, wherein the thicknesses (7) of the gaps and the thicknesses (8) of the cells are coordinated with each other such that the latent heat storage cell (4) releases an accumulation temperature at a release rate of at least 100 watths / min. wherein the free lattice elements (10) are arranged such that a turbulent flow is formed on the free lattice elements (10) at a cooling water flow rate corresponding to the rate of release of the storage temperature, and wherein latent heat storage cells (4) abut the elements (9) The grids compensate for the change in the volume of latent heat storage cells (4) resulting from the phase change of the storage medium without limiting the formation of turbulence on the free elements (10) of the lattice. Motor vehicle heat accumulator according to claim 1, characterized in that, when released, at least 50% of the stored heat is transferred to the cooling water in two minutes. Motor vehicle heat accumulator according to claim 1 or 2, characterized in that the latent heat storage cells (4) have barium hydroxide osmate or a mixture thereof based on barium hydroxide eight hydrate as the storage medium. Motor vehicle heat accumulator according to one of claims 1 to 3, characterized in that the latent heat storage cells (4) are arranged substantially horizontally in the inner vessel (1). Motor vehicle heat accumulator according to one of Claims 1 to 4, characterized in that the latent heat storage cells (4) are formed from a thin copper sheet. 6th Motor vehicle heat accumulator according to one of the claims 1 to 5, characterized in that the latent heat storage water storage cells (4) have a maximum direction in length 500 mm flow and are made of sheet metal with a thickness of 0.1 to 0.15 mm. Motor vehicle heat accumulator according to one of Claims 1 to 6, characterized in that. The thickness of the gap (7) is about 1.5 mm. 8th Motor heat accumulator vehicles by one of claims laž7, characterized by s a by that thickness (8) cells have a value of about 6.5 mm. 9th Motor heat accumulator wagon i d a by one of claims 1 to 8, characterized by s a because of the individual latent heat storage cells (4) have an accumulation capacity of 30 to 70 watts-hours. Motor vehicle heat accumulator according to one of Claims 1 to 9, characterized in that the release rate is about 120 watth-hours / min. Motor vehicle heat accumulator according to one of Claims 1 to 10, characterized in that the free grid elements (10) and the bearing grid elements (9) have rounded cross-sections and / or a rectangular cross-section with rounded corners and intersecting corners between the free elementary elements. (10) lattices and also have rounding (11) between abutting elementary (9) lattices.