DE19528138A1 - Low temp. heat storage device - Google Patents

Abstract

The heat storage device has two or more stacked identical containers (1), each filled with water or a different heat storage fluid at a given pressure, above or below atmospheric pressure, each provided with external connection lines. Pref. the containers are stacked together with intermediate heat insulation plates (8) between them, one of the containers used for a special application, e.g. top-up heating via solar energy, with the lowest container acting as an expansion vessel for the heat storage fluid.

Description

The present invention relates to a liquid filled heat storage for low temperature heat with Temperature stratification, with the storage volume in an upper Zone of the highest possible temperature and in a lower zone temperature is as low as possible. Typical An Applications of such heat storage are z. B. heat storage of thermal solar systems and heat recovery systems as well as heat buffer storage in heating systems and power Heat coupling systems.

A distinction must be made when loading this heat storage between the heating of the storage liquid by the in Storage inside heat exchangers and heating the storage liquid outside the storage by a external heat exchanger. Because the heat exchanger inside of the heat storage necessarily in the storage at the bottom must be arranged, the tem temperature layering totally destroyed. Hence the Invention on heat storage by an external heat exchanger be loaded. Due to the external loading heat transmitter circulates the storage fluid, the Storage fluid taken from the lower cold storage zone and after heating in the heat exchanger at the desired Temperature is layered into the storage from above. Such stores are therefore empty containers. This method is widely used in practice, with the necessary Storage volume - if possible - in a container leads. It proves to be very thermodynamically partly that the entire storage mass is thermally coupled is. Through heat conduction and free convection, both in the storage liquid as well as heat in the container wall transported from the hot storage zone to the cold zone,  this automatically running compensation process only at a thermodynamic equilibrium state, i.e. with the same temperature in the entire storage tank ends. The result is a steady loss of usable heat from the hot food zone and a steady reduction in storage capacity. Heat storage over several days, weeks or nonates is not possible with this usual memory design.

For manufacturing reasons and often also for spatial reasons become larger storage volumes by placing several Individual storage realized, which are then hydraulically in series or be connected in parallel. It is wanted or unwanted, extensive thermal decoupling of the Container achieved, but this procedure results compared to the one-tank design, significantly greater heat memory losses due to a large surface / volume ver ratio. The increase in. Is even more serious for practice specific storage costs in DM / m³ due to the number of containers and the necessary piping and insulation effort.

The present invention avoids the above Disadvantage; it includes an inexpensive, modular Storage tank system with which in a modular design any storage volume can be realized, with in assembled state a thermal separation of the individual modules, the smallest possible surface / volume ratio ratio and a simple hydraulic series connection of the Modules is realized.

The invention is described in more detail with reference to FIG. 1, which shows the subject of the invention by way of example.

The heat accumulator is made up of two or more stackable ones Containers, built according to the required storage volume.  

Here, identical, prefabricated containers 1 are preferably stacked on top of one another. Depending on the arrangement of the individual container (top, middle, bottom), part of the inlet / outlet connection piece is used in accordance with the function, or the unused connection pieces are closed blindly. There is the loading of the memory by removing cold storage liquid speed at the lowest connector 3 and stratification of this liquid after heating in an external heat exchanger 7 through the top connector 4 in the top storage tank. The overflow lines 2 between the containers enable the entire store to be loaded from top to bottom. The connecting pieces 5 , 6 are used for storage discharge.

The stacked container design enables the thermal decoupling of the individual containers by interposing pressure-resistant insulation panels 8 . This means that the temperature stratification from individual container to individual container is retained and the basic requirement for heat storage over longer periods (several days, weeks, months) while maintaining maximum storage capacity is met.

At the same time, this stacked container design offers great Cost advantages, since all containers are manufactured identically without transported and through special doors Spaces can be brought.

Further characteristics and features of the present invention are the subject of further subclaims and result from the following description of preferred embodiments games.

Fig. 2 shows a container stack, the uppermost container ter 9 z. B. in a thermal solar system takes over the function of the heat storage standby with post-heating.

This year-round container 9 can be optimized in its geometry for minimal heat loss and thus deviate from the shape of the other stacking containers required only at times of solar radiation. Also for the standby part, the thermal decoupling to the tank underneath proves to be a great part, since post-heating - as a result of heat losses in the lower storage areas - is avoided.

Fig. 3 shows a container stack, the uppermost container 10 assumes the function of the expansion tank for the storage liquid in the container stack. This container can in its geometry, for. B. height, deviate from the underlying container ter, here, too, the thermal decoupling is again advantageous.

Fig. 4 shows that depending on the storage volume required and the existing room geometry, several container stacks can be built next to each other and hydraulically very easily connected.

Without a figurative illustration, the subordinate claim is the expedient and inexpensive thermal insulation of the Concerning container stack. In addition to the possibility of one Conventional heat insulation is according to the invention seen the stack of containers in an existing or with a simple partition to create a separate room to arrange and including supply lines and connecting lines between the containers with heat-insulating bulk goods the basis of inorganic substances or organic substances (bio mass) to insulate against heat loss. This insulating material Filling fills all spaces around the container stack (s) in ideal manner and thus creates the maximum possible location Thermal insulation.

Reference list

1 container
2 overflow line
3 , 4 connecting piece for storage tank loading
5 , 6 connection piece for storage discharge
7 External heat exchanger
8 thermal insulation panel
9 Heat storage standby with post-heating
10 Expansion tank for storage liquid

Claims (7)

1. Storage for low-temperature heat, filled with water or another liquid suitable for heat storage, subatmospheric pressure or overpressure / underpressure, characterized in that the storage is constructed from two to any number of stackable containers with outer connecting lines. 2. Memory according to claim 1, characterized in that the individual containers in the stack by intermediate layers insulated from each other from pressure-resistant thermal insulation materials are. 3. Memory according to claim 1, characterized in that mainly stackable containers with identical Ab measurements and connections are used. 4. Memory according to claim 1 and 3, characterized records that a storage sub-volume with special Task such as B. standby part with afterheating thermal solar systems, with dimensions other than the rest of the memory stack is executed. 5. Memory according to claim 1 to 4, characterized records that the expansion tank for the memory liquid in the container stack, e.g. B. as the top Container, is integrated.   6. Memory according to claim 1, characterized in that with a limited overall height several container stacks ne assembled and hydraulically ver be bound. 7. Memory according to claim 1, characterized in that the container stack (s) including supply lines and connections cables between the containers with thermal insulation bulk goods based on inorganic substances or organic substances (biomass) against heat loss is / are insulated.