DE202011000562U1 - layer memory - Google Patents

Abstract

Stratified storage, in particular for a solar thermal assisted heating system, which can be filled with a liquid serving as a heat storage medium and by two vertically spaced intermediate floors (3, 4) in an upper chamber (10), a middle chamber (20) and a lower chamber (30 ), wherein a first heat exchanger unit (11) is disposed in at least the upper chamber (10) and a second heat exchanger unit (31) is disposed in the lower chamber (30), and wherein the upper chamber (10) and the middle chamber (20) each have a feed (14, 24) and a return (15, 25) for the liquid, characterized in that
- The shelves (3, 4) are arranged or configured so that the lower chamber (30) to the central chamber (20) is hydraulically connected and the central chamber (20) to the upper chamber (10) is hydraulically connected and
- There is at least one additional direct hydraulic connection, through which the lower chamber (30) directly with ...

Description

The invention relates to a stratified storage tank, in particular for a solar thermal assisted heating system, which can be filled with a liquid serving as a heat storage medium and which is divided by two vertically spaced intermediate floors in a lower chamber, a middle chamber and an upper chamber, wherein a first heat exchanger unit in the lower chamber is arranged and a second heat exchanger unit is arranged in at least the upper chamber, and wherein the middle chamber and the lower chamber each have a supply and a return for the liquid.

Such stratified storage serve as a heat storage for heating and hot water systems. They are typically approximately cylindrical in construction, wherein the height of the cylinder significantly exceeds its diameter, so that inside a vertical layering of serving as a heat storage medium liquid, in which the temperature of the liquid increases from bottom to top. The vertical temperature gradient in the stratified tank allows coupling to different heat sources (thermal with gas or oil burner, air or ground heat pump, solar thermal system) and heat sinks (consumers, such as heating circuit, domestic water heating, defrost cycle of an air heat pump) at different temperature levels.

For connection to the heat sources or sinks serve the liquid feeds and the liquid recirculation of the stratified storage tank, if the corresponding heat source or sink is operated directly or via an external heat exchanger with the liquid with which the stratified storage tank is filled. This is the case for example in a gas or oil thermal and indirectly via an external heat exchanger in a heat pump.

Heat sources or sinks, which are operated with a different liquid than that in the stratified storage tank, are connected via the heat exchanger arranged in the stratified storage tank with the latter, for example the solar thermal system and the heating of the process water.

When liquid flows in and out of the stratified storage fluid, turbulence of the liquid can occur which leads to a mixture of differently tempered liquid. To minimize this, it is known to arrange intermediate floors in the stratified storage, which subdivided the stratified storage into different chambers, which are associated with different temperature ranges. In this way, three chambers are created: the lower chamber, the middle chamber and the upper chamber, usually the solar thermal system gives its heat to the lower chamber, the domestic water heating covers their heat demand from the upper chamber and the middle chamber is either connected to a heating circuit in order to supply the heat supplied by the solar thermal system to a heating circuit or to an air heat pump in order to supply heat for a thawing cycle if necessary. As a result of the intermediate floors, heat supplied by the solar thermal energy is supplied almost exclusively to the middle chamber directly adjacent to the lower chamber. At high solar radiation, however, the solar thermal system is able to produce heat at a temperature level that could be used more effectively for domestic water heating to a use of fossil energy (oil, gas) through the spa to heat the upper chamber to one for domestic water heating to reduce sufficient temperature. In such a situation, the intermediate floors prevent heat supplied by the solar thermal system from being used for its most effective use.

It is therefore an object of the present invention to provide a stratified storage in which Verwirblungen for mixing different tempered liquids are effectively prevented and at the same time allows effective use of the introduced into the lower chamber of the stratified storage heat.

This object is achieved by a layer memory having the features of the independent claim.

According to the invention, a stratified storage of the type mentioned above is characterized in that the intermediate floors are arranged or configured so that the lower chamber is hydraulically connected to the middle chamber and the middle chamber is hydraulically connected to the upper chamber and that at least one additional direct hydraulic There is a connection through which the lower chamber is directly hydraulically connected to the upper chamber.

The additional direct hydraulic connection allows solar heat, which is usually introduced into the lower chamber of such a stratified storage, can also be delivered directly to the upper chamber and there directly, z. B. can be used for domestic water heating.

In a preferred embodiment of the stratified storage, the additional direct hydraulic connection is formed by at least two tubes, which are guided through the intermediate floors and having the ends positioned respectively in the lower chamber and the upper chamber. Preferably, one of the tubes extends with its upper end not or only slightly beyond the upper of the intermediate floors, whereas its lower end is located well below the lower of the intermediate floors. Also preferably, another of the tubes extends with its lower end not or only slightly below the lower shelf, while its upper end is located well above the upper shelf. In this way it is achieved that a significant fluid exchange via the additional direct hydraulic connection only at those temperature levels in the lower and upper chamber begins, in which the heat of the lower chamber in the upper chamber is effectively used.

Further advantageous embodiments and further developments of the stratified storage are the subject of the dependent claims.

The invention will be explained in more detail below with reference to an embodiment with the aid of two figures, which show a layer memory in different sectional views.

In the 1 and 2 a first embodiment of a stratified storage is shown. The figures are sectional drawings from which the outer shape of the stratified storage, its connections with which the stratified storage is connected to other components of a heating and hot water system, as well as arranged in the interior of the stratified storage and usually not visible components of the stratified memory emerge. In part, the inner components of the stratified memory are completely or partially hidden in the figures in order to be able to clearly represent the overall structure of the stratified memory in the combination of both figures. The following are the 1 and 2 therefore explained together.

The layer memory has a substantial hollow cylindrical body 1 on, on the open ends end caps 2 are placed, preferably by a braze or welded joint with the body 1 are connected. The inner volume of the stratified storage tank is completely hermetically sealed from the environment and during operation of the stratified storage tank in a heating and hot water installation, it absorbs the liquid which is used as the heat storage and heat exchange medium in the installation. Hereinafter, this liquid is referred to as a storage liquid for the sake of simplicity.

Before in the manufacturing process of the main body 1 above with one of the end caps 2 is closed, is in the main body 1 an insert is used which comprises the inner components of the stratified storage. These include two false floors 3 . 4 , which are spaced apart in the central region of the stratified storage. The shelves 3 . 4 subdivide the stratified storage into three areas or chambers called an upper chamber 10 , a middle chamber 20 and a lower chamber 30 ,

In addition to the aforementioned shelves 3 . 4 The insert used in the stratified storage tank comprises a first heat exchanger 11 and a second heat exchanger 31 , For clarity, the second heat exchanger 31 in the 1 not shown. 2 shows the first heat exchanger only in sections for the same reasons. Both heat exchangers are formed by coiled tubing, each with two connections 12 . 13 respectively. 32 and 33 have, which are guided out of the stratified storage. The heat exchangers 11 . 31 are completely sealed against the inner volume of the stratified storage. For mechanical support of the first heat exchanger 11 and possibly also the second heat exchanger 31 and other components of the insert is a carrying frame 9 , For example, plastic, provided.

The stratified storage shown is particularly suitable for use with a solar thermal system. Solar collectors of the solar thermal system are connected via the connections via a liquid circuit 32 and 33 with the second heat exchanger 31 connected. This heat exchanger is located completely in the lower chamber 30 the stratified storage. The first heat exchanger 11 is intended for domestic water heating. He is at least in the upper chamber 10 arranged, in the illustrated embodiment is a part of the first heat exchanger 11 also in the lower chamber 30 arranged, wherein the coil of the first heat exchanger 11 doing so without further loops as directly as possible through the middle chamber 20 is guided.

Due to the different density of a liquid at different temperatures, a temperature gradient arises within the stratified storage during operation, in which fundamentally warmer storage liquid is stacked further upwards and colder storage liquid further down. The second heat exchanger 31 feeds at the lowest possible temperature of the storage liquid, which allows a high efficiency of the solar thermal system. In contrast, brewing water is required at a relatively high temperature level of about 55 ° -60 °, which is why the raw coils of the first heat exchanger 11 to the upper part of the upper chamber 10 from where the service water they are above the upper port 13 to the points of consumption. The arranged in the lower chamber part of the first heat exchanger 11 essentially serves to preheat the over the lower port 32 supplied hot water via heat of the solar thermal system.

To replace the storage liquid in the stratified storage tank are in the upper chamber 10 the stratified storage a feeder 14 and a return 15 intended. Inside the stratified storage are in the area of the feeder 14 and the return 15 baffles 16 . 17 arranged to prevent excessive Verwirblung the storage fluid stored within the stratified storage. The feeder 14 and a return 15 are typically associated with a fossil-fueled spa or heat pump that is used as needed to achieve the required high temperature level for service water heating.

Another feeder 24 and another return 25 the storage liquid is in the area of the middle chamber 20 arranged. This feeder 24 and repatriation 25 may be connected to a heating circuit, such as underfloor heating, to use heat through the storage fluid at a medium temperature level for heating. Alternatively, the feeder 24 and repatriation 25 be connected to an air heat pump to use the storage liquid as a heat source for a defrosting can. In the case, the middle chamber 20 used as a buffer. Within a heating system can be provided, the middle chamber 20 to use for both purposes, which can be realized for example by three-way valves o. Ä.

They are also located in the upper chamber 10 and the middle chamber 20 one flange or threaded connection each 18 respectively. 28 , in each of which an electric heating element can optionally be used.

It is understood that the stratification of the storage liquid due to density differences is not necessarily given at any time, but that this stratification may be disturbed by non-equilibrium states in an introduction or removal of heat from the stratified storage or due to turbulence when replacing the storage liquid.

In particular, a redistribution due to turbulence in the supply and the return of the storage liquid through the supply 14 . 24 and the return 15 . 25 To reduce the stratification is through the shelves 3 . 4 in the mentioned three chambers 10 . 20 . 30 divided. However, the subdivision is not the nature of having a fluid exchange between the different chambers 10 . 20 . 30 would be prevented. Rather, defined options for fluid exchange, including hydraulic connections, between the chambers 10 . 20 . 30 intended.

An exchange of the storage liquid between the chambers 10 . 20 . 30 is given by the fact that the shelves 3 . 4 in diameter are smaller than the inner diameter of the hollow cylindrical body 1 , As a result, one around the shelves 3 . 4 circumferential gap 5 . 6 educated. Through the gap 5 can warm fluid from the lower chamber 30 in the middle chamber 20 and vice versa colder fluid from the middle chamber 20 into the lower chamber 30 , Accordingly, by the upper circumferential gap 6 warmer fluid from the middle chamber 20 in the upper chamber 10 arrive and vice versa colder liquid 10 from the upper chamber 10 in the middle chamber 20 reach.

The width of the column 5 . 6 is in the range of a few millimeters (mm), for example between 1 and 5 mm and preferably between 1 and 3 mm.

It is understood that a fluid exchange between the different chambers 10 . 20 . 30 could also be achieved by the fact that the shelves 3 . 4 have corresponding perforations or openings. An advantage of the circumferential column 5 . 6 is, however, that they are in the edge region to the wall of the body 1 are located. If by an influx of storage liquid through the supply 14 or the further feed 24 a fluid movement within the upper chamber 10 or the middle chamber 20 is used, this movement is due to the influence of the inner wall of the body 1 in the immediate vicinity less strong, than in further from the main body 1 spaced areas. Accordingly, an exchange of liquid between the chambers, not caused by temperature differences but merely by a fluid movement, becomes 10 . 20 respectively. 20 . 30 through the circumferential gap 5 . 6 kept as small as possible.

Furthermore, to replace the storage fluid between different chambers in the shelves 3 . 4 used pipes 7 . 8th intended. These pipes 7 . 8th allow immediate exchange of storage fluid between the lower chamber 30 and the upper chamber 10 , The pipes 7 . 8th are sealed in corresponding openings of the shelves 3 . 4 used, for example, welded. Their openings end in the upper chamber 10 and the lower chamber 30 , Through the middle chamber 20 are the pipes 7 . 8th guided, without a hydraulic connection from one of the chambers 10 . 30 in this middle chamber 20 through the pipes 7 . 8th is formed.

The pipes 7 . 8th are each about the same length, but arranged at different heights within the stratified storage: the tubes 7 with an upper end are not or only slightly above the upper shelf 4 whereas they have a lower end well below the lower shelf 3 ending at about the middle height in the lower chamber 30 , The reverse is the pipe 8th arranged so that a lower end flush with the lower intermediate floor 3 is or only slightly down over this intermediate floor 3 protrudes, whereas the upper end of the tube 8th clearly above the upper shelf 4 in the upper chamber 10 is positioned. The dimension of the tubes should be within the range of DN 50 (Diameter Nominal - approximate inner diameter 50 mm) to allow sufficient fluid exchange for rapid temperature cycling.

About the pipes 7 . 8th then sets a fluid exchange between the upper chamber 10 and the lower chamber 30 when the storage fluid is in the upper area of the lower chamber 30 a temperature is higher than in the lower part of the upper chamber 10 , As already mentioned, it is provided, the second heat exchanger 31 to connect with a solar thermal system. If due to high solar radiation in the upper part of the chamber 30 sets a temperature that is high enough to lower the temperature in the lower part of the lower chamber 10 exceeds, the thus heated storage liquid through the pipe 8th directly into the upper chamber 10 rising, in turn, liquid of a lower temperature from the lower part of the upper chamber 10 into the lower chamber 30 can sink down. If due to increased sunlight storage fluid in the stratified storage through the second heat exchanger 31 brought to a temperature level by the solar thermal system that is used to heat liquid in the upper chamber 10 and is therefore suitable for domestic water heating, it makes sense to use the solar heat for precisely this purpose. As previously stated, in the upper chamber 10 Storage fluid at a high temperature level for DHW heating via the first heat exchanger 11 benötig. A temperature at a level of about 55 to 60 ° in the upper part of the chamber 10 Conventionally, it can only be achieved by applying primary energy. Heat energy to maintain the temperature level in the upper chamber 10 can thus be obtained either only solar thermal or must by conventional heat generators on the supply 14 the upper chamber 10 be supplied. If it is the temperature level in the lower chamber 30 For reasons of environmental protection and the reduction of energy costs, the most sensible use of this heat energy is the supply of heat to the upper chamber 10 , This is due to the arrangement of the pipes 7 and 8th reached. At suitable temperature conditions adjust the tubes 7 and 8th a kind of thermosiphonic priority circuit for the supply of heat energy from the solar thermal system in the upper chamber 10 and thus for domestic water heating there. This is under the given conditions against using the heat of the heating circuit via the middle chamber 20 prefers. If due to this thermosiphonic priority circuit, the solar energy is no longer sufficient for a possible need for heating heat, this heating heat can be easily provided via a heat pump, as the amount of heat to the higher temperature level, which is needed for domestic water heating.

Alternative to the tubes shown 7 . 8th passing through the middle chamber 20 are also externally arranged on the stratified storage tubes as direct hydraulic connections of the upper chamber 10 with the lower chamber 30 be used. The external tubes may in turn end up at different heights in the inner volume of the stratified storage.

LIST OF REFERENCE NUMBERS

1

body

2

endcap

3, 4

false floor

5, 6

gap

7, 8

pipe

9

carrying frame

10

upper chamber

11

first heat exchanger

12, 13

connection

14

feed

15

return

16, 17

baffle

18

Flange for electric heating

20

middle chamber

24

feed

25

return

28

Flange for electric heating

30

lower chamber

31

second heat exchanger

32, 33

connection

Claims (10)

Stratified storage, especially for a solar thermal assisted heating system, with a fluid serving as a heat storage medium is filled and by two vertically spaced intermediate floors ( 3 . 4 ) in an upper chamber ( 10 ), a middle chamber ( 20 ) and a lower chamber ( 30 ), wherein a first heat exchanger unit ( 11 ) in at least the upper chamber ( 10 ) is arranged and a second heat exchanger unit ( 31 ) in the lower chamber ( 30 ), and wherein the upper chamber ( 10 ) and the middle chamber ( 20 ) each a feeder ( 14 . 24 ) and a return ( 15 . 25 ) for the liquid, characterized in that - the intermediate floors ( 3 . 4 ) are arranged or configured so that the lower chamber ( 30 ) with the middle chamber ( 20 ) is hydraulically connected and the middle chamber ( 20 ) with the upper chamber ( 10 ) is hydraulically connected and - there is at least one additional direct hydraulic connection through which the lower chamber ( 30 ) directly with the upper chamber ( 10 ) is hydraulically connected. Stratified storage according to claim 1, wherein between each of the intermediate floors ( 3 . 4 ) and a wall of a base body ( 1 ) of the stratified storage one gap each ( 5 . 6 ) is provided. A layered memory according to claim 2, wherein the column ( 5 . 6 ) encircling the intermediate floors ( 3 . 4 ) are executed. Layered memory according to Claim 2 or 3, in which the column ( 5 . 6 ) have a width of about 1 to 5 mm and in particular in the range of about 1 to 3 mm. Stratified storage tank according to one of Claims 1 to 4, in which the intermediate floors ( 3 . 4 ) Have openings in their surface. Stratified storage tank according to one of claims 1 to 5, in which the additional direct hydraulic connection through at least two pipes ( 7 . 8th ) formed by the intermediate floors ( 3 . 4 ) are guided and have ends, each in the lower chamber ( 30 ) and the upper chamber ( 10 ) are positioned. Stratified storage tank according to Claim 6, in which one of the tubes ( 7 ) with its upper end not or only slightly above the upper of the intermediate floors ( 4 ), whereas its lower end is well below the lower of the intermediate floors ( 3 ) is arranged. Layered store according to Claim 7, in which the lower end of the tube ( 7 ) in a vertically central region of the lower chamber ( 30 ) is positioned. Stratified storage tank according to one of Claims 6 to 8, in which one of the tubes ( 8th ) with its lower end not or only insignificantly below the lower intermediate floor ( 3 ), whereas its upper end is clearly above the upper intermediate floor ( 3 ) is arranged. Stratified storage according to claim 9, in which the upper end of the tube ( 8th ) in a vertically approximately middle region of the upper chamber ( 30 ) is positioned.

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