EP1740890A1

EP1740890A1 - Heating and hot water supply unit and method for operating the same

Info

Publication number: EP1740890A1
Application number: EP05733255A
Authority: EP
Inventors: Dietmar Lackinger; Harald NEUMÜLLER; Karl-Heinz Hinrichs
Original assignee: Prefa Aluminium Produkte GesmbH
Current assignee: Prefa Aluminium Produkte GesmbH
Priority date: 2004-04-28
Filing date: 2005-04-27
Publication date: 2007-01-10
Also published as: ATA7342004A; AT505554B1; WO2005106349A1; US7575047B2; RU2310137C1; US20060159154A1; AT412818B

Abstract

The invention relates to a heating and hot water supply unit, using a heat pump (24) with a heat exchanger (18), through which water from a tank (11) flows and heats a medium from the heat pump, whereby a pump (15) is provided, by means of which tank water may be pumped to a roof (1,2) and evenly distributed there and the water flowing over the outside of the roof is returned to the tank by means of roof gutters (7a). The heat exchanger is embodied with a series of segments, provided with a supply manifold and a return manifold, connected by the heat exchanger elements, whereby the adjacent heat exchange segments flow counter-currently and with a controller (35), which controls the pump, depending on signals from temperature sensors (32 to 34), such that, in normal operation, water is pumped from the tank to the roof, however, with a risk of frost, the supply of water to the roof is interrupted, the distribution lines (5,6) are emptied and the heat capacity of the water in the tank is used.

Description

Heating and hot water preparation system and method for operating such.

The invention relates to a heating and / or hot water preparation system with a device for heating water under the influence of environmental energy, which water can be stored in a container, for example a rainwater cistern or the like. Furthermore, with a heat pump, with a first, external coolant circuit with a heat exchanger which is fed by water from a rainwater cistern or the like, in which heat exchanger by the

Heat pump coming cold medium is heated and returned to the heat pump, whereby if the cistern is buried in the ground, the cistern water extracts heat from the surrounding ground by heat exchange through the wall of the cistern and thus warms the water again and a pump is provided with which water from the cistern is on Roof can be conveyed where it can be distributed, in particular evenly, in the upper area of the roof area and where the water flowing over the roof skin can be collected in gutters and returned to the cistern

Energy from various sources is subsumed under the term "environmental energy" used above: firstly energy from direct sunlight, but also energy from diffuse radiation, heat transfer through warm ambient air, whereby the heat transfer can be supported by wind and finally the heat that results a not perfect insulation of the house escapes through the roof.

Heat pumps represent a particularly elegant and energy-saving device for low-temperature and water treatment systems. They are able to heat from a low temperature level, for example well water of, for example, 10 ° C. to pump to a temperature of 30-50 ° C. Depending on the parameters of such a system, performance figures of up to 6 can be achieved. (The coefficient of performance indicates how much greater the thermal output of the system compared to the electrical power supplied). Powerful so-called However, water / water heat pumps require a supply of not inconsiderable amounts of water, which are typically obtained from wells. The water cooled in the heat pump must then be returned to the groundwater via swallowing wells. In general, this not only results in extremely high investments, but is increasingly rejected by the authorities with regard to the risk of groundwater contamination.

Another method is to extract heat from the ambient air. These systems require a very high air throughput, which can lead to rather modest performance figures and considerable noise emissions. In winter, the heat exchangers typically freeze, which necessitates regular defrosting, which further reduces the average coefficient of performance.

In order to solve the problems of high water requirements in water / water systems and at the same time to improve the coefficient of performance, a variant of the previous systems was proposed in DE 101 39 065 AI. According to this publication, a solar collector mounted on a roof is provided which is connected to a water storage device, the heated water of which heats the evaporator of a heat pump and which pumps the supplied heat to a higher temperature level.

Facilities of this type have proven to be not without problems in practice:

Improvements were possible with this solution, but the environmental problem remained, but with a different argument: to freeze the

It is to avoid systems, especially the solar collector in winter It is necessary to provide the water in this circuit with an anti-freeze, e.g. with glycol or with sodium chloride. If there is a leak in this system, a relatively large amount of water contaminated with frost protection can escape and eventually reach the groundwater.

This is the reason why the authorities are increasingly refusing approval for such facilities, not only in water protection areas but also in many other areas with an environment worth protecting.

Another reason that particularly discourages homeowners and potential installers from such systems is, on the one hand, the unfavorable appearance: those consisting either of glazed boxes that enclose the actual collectors or of black plastic must be mounted on the roof skin and contrast in generally very strong with the roof skin consisting of roof tiles, bricks or colored coated aluminum panels, so that the appearance of a

House with such a system is severely impaired from an aesthetic point of view. In view of the relatively high price of such collectors, but also for aesthetic reasons, an attempt is therefore made to find the minimum with a minimal collector area, but this results in a low heat pump performance figure on average over the year.

It has already been proposed to use roof heating by sprinkling with water and to discharge the water heated in this way into a cistern. A cistern water is pumped through a heat exchanger to the distribution pipes on the roof surfaces. Such systems are described, for example, in German patent application DE 33 10 228, French patent application FR 2 566 032. Similar systems are the subject of US Patents 4,340,036, 4,052,975 and 2,660,863. Systems of this type work satisfactorily as long as the cistern water has a temperature well above 0 ° C. Problems arise, however, when the temperature of the cistern water drops in the range of 0 ° C. Especially occur in the months of January and February In numerous regions of Central Europe there are occasional weather conditions in which the roof surface does not heat up due to direct and largely indirect radiation and the air temperatures are below 0 ° C. In these conditions in particular, the heat requirement is high, but cannot be covered or can only be covered to a small extent by the systems described above, so that an additional heater, generally an electric heater, must be used. The system's coefficient of performance then lies in the range of 1 and leads to a deterioration in the annual coefficient of performance, which is crucial for assessing the efficiency of a heating system.

With an arrangement of the heat exchanger as shown, for example, in DE 33 10 228, the heat exchanger is iced up at these temperatures, starting with the supply of the brine cooled to, for example, -4 ° C. in the heat pump. Such ice formation is inevitable when the latent heat of the water is used, but it is crucial that the formation of larger, massive ice volumes is avoided. The aim of the invention is to produce ice layers on a heat exchanger with a relatively large surface area, which in turn have a large surface area. The deterioration of the heat transfer through the ice layers is compensated for by a correspondingly more generous dimensioning of the heat exchanger. Among these, unfavorable ones that occur relatively rarely in the course of a year

Weather conditions will probably have to accept a short-term reduction in the instantaneous value of the system's coefficient of performance. It is essential, however, that as soon as a little warmer water is introduced into the cistern, the ice layers are quickly thawed due to their large surface area, thus increasing the instantaneous coefficient of performance again. The icing of the heat exchanger that occurs occasionally when using the latent heat thus has no appreciable influence on the annual output number of the system, which is decisive for its economic operation.

According to the invention, this is achieved in that the heat exchanger is constructed from a number of segments, each of which has a flow and a return collector, which are essentially tubular or plate-shaped parallel heat exchange elements connected to each other, around which the cistern water flows and through which the coolant of the heat pump can flow, whereby the adjacent heat exchanger segments can be flowed in opposite directions and the flow and return collectors of the adjacent segments are arranged directly next to one another, furthermore with an electronic control in particular, which depends on of signals from temperature sensors on the roof surface, in the cistern and / or in lines controls the pump and any valves, so that in normal operation water is pumped from the cistern to the roof, heated there and can be returned to the cistern if there is a risk of freezing Water in the distribution pipes or on the roof skin the pump and valves are controlled so that the

Pumping the water to the roof is interrupted and the distribution pipes and possibly also their feed lines are emptied and preferably the pump ensures that the water in the cistern is circulated, so that the thermal capacity of the water in the cistern including at least a portion of the latent heat thereof and, if applicable, that from the Cistern wall geothermal energy is usable.

Such a solution requires only a small investment, so that in general the entire roof area can be used to heat the secondary water, but at least the areas that are exposed to high levels of radiation (east, south or west). A further advantage of this solution is that the roof is in no way visually impaired by this use of solar energy, since the roof skin itself is used as a heat source and, in a further advantageous embodiment of the invention, the distributor pipes for uniformly sprinkling the roof skin, covered in ridge riders can be.

The object of the invention also has significant advantages over the prior art with regard to environmental aspects. According to the invention, pure water, in particular rainwater, is used for filling the cistern, so that even if the system leaks, the environment is not polluted, in particular the groundwater cannot be contaminated. It is therefore also permissible to overflow the cistern into the

To discharge groundwater. According to an alternative to the subject matter of the invention described above, the heat exchanger is designed as a counterflow heat exchanger through which the medium from the evaporator circuit of the heat pump can flow and on the other hand the cistern water. The cooled cistern water emerging from the heat exchanger is conveyed via a valve to the distributor pipes on the roof and finely distributed on the roof surface. A connecting line with a valve is provided between the supply line to the distribution pipes and the cistern, which leads into the supply line to the distribution pipes upstream of the valve. The system also has an electronic control, in particular, which is dependent on signals from temperature sensors on the roof surface, in the cistern and / or in

Controls the lines, the pump and the valves so that in normal operation water is pumped from the cistern to the roof, where it is heated and can be returned to the cistern.If there is a risk of freezing of the distributor pipes and the roof covering, the valves and the pump are controlled in such a way that the cistern water cooled in the counterflow heat exchanger can be returned directly to the cistern via the open valve, so that the thermal capacity of the water in the cistern including at least a part of the latent heat of the cistern and possibly the geothermal energy supplied through the cistern wall can be used. It is essential in this variant of the invention that the ice crystals formed when the latent heat of the water is used are flushed through the flow from the heat exchanger into the cistern and one

Ice formation in the counterflow heat exchanger is prevented.

Further advantages of the invention result from the subject matter of the subordinate claims 2 and 3 and 5 to 13 inclusive.

Patent claims 14 to 17 describe a method for operating a heating and water heating system with a water tank, in particular the cistern, which is initially filled with preferably rainwater, followed by this water via a heat exchanger in which the cold brine coming from a heat pump or the like is heated and in normal operation by means of a pump or the like, if necessary, periodically passed onto a roof and then on this or the like. Periodically passed onto a roof and then finely distributed thereon, the water heated on the roof skin being collected in a rain gutter and being returned to the water tank.

According to a further feature of the invention, the risk of freezing the

Water, especially at roof skin temperatures below 1 ° C, the manifolds and supply lines are emptied and shut off by closing the valves. In this operating state, the thermal capacity of the cistern water including at least part of the latent heat of the same and, when the cistern is sunk in the ground, the heat supplied by the geothermal heat of the cistern for heating the

Brine or the like. The heat pump used. Appropriate control of the pump and the valves allows mixing of the water in the cistern to be achieved, so that local hypothermia is largely avoided. The feed pump is advantageously switched on in summer operation, in particular when the heat pump is switched off, the cooler running over the roof skin

Cistern water causes cooling of the roof directly and additionally by evaporation and, if the cistern is buried in the ground, the comparatively warm cistern water heats up the surrounding soil, which in addition provides heat in heat pump operation to heat the cistern water. An important aspect of the new process is that the roof skin is kept free of snow as much as possible, since the thermal insulation effect of the snow means that no heat can be transferred from the surroundings to the roof. To avoid this, the sprinkling of the roof surface can be switched on via a snow sensor or a switch that can be actuated by hand, so that the snow is thawed immediately in snow or snowfall and the roof is thus covered by

Snow is freed. The snow can also be defrosted using other means, such as heating cables, such as those used for gutter heating.

Further features of the invention result from the following description of some exemplary embodiments and with reference to the drawing. The Fig.l shows schematically a system according to the invention, Figures 2a to 2c represent a first embodiment of a heat exchanger in different views. Figures 3 and 4 show variants of heat exchangers in axisionometric representation, Fig. 5 shows the associated installation diagram. FIGS. 6 and 7a, 7b show different variants of distributor pipes. Finally, FIG. 8 illustrates one

Variant of the system according to the invention, Figure 9 shows a detail of the same.

Fig. 1 shows schematically a heating and hot water preparation system for example for a family home. The house has a pent roof with a roof skin on the side facing the sun (south or west) 1. A water distribution pipe 5 is arranged in the upper area of the roof. Such a tube 5 is shown in detail in FIG. 6. The distributor pipe is made of stainless steel or plastic and has at the ends facing away from the feed pipe 3 a vertically upwardly directed pipe socket 65. On the underside, the distributor pipe 5 has a series of small bores 66 through which the water is uniformly distributed over the roof surface is distributed. The two branches of the distributor pipe 5 can have a slight slope towards the pipe socket 65. The pressure of the feed pump 15 is set so that the water level in the two pipe sockets 65 is approximately halfway up. The water therefore emerges along the entire pipe 5 from the bores 66 with a low, defined pressure. at

Switching off the pump empties the tube 5 completely, so that it cannot freeze in the event of frost. Another advantage of this arrangement is that the alignment of the distribution pipes on the roof is relatively uncritical. If necessary, the inlet pressure can also be adjusted with appropriate throttles.

The water trickling over the roof surface is collected in the gutter 7a. The water is fed to a cistern 11 through rain pipes 7b. This cistern is filled with rainwater, only when the system is commissioned will it generally have to be at least partially infested with water from a utility or drinking water line. A schematically illustrated heat exchanger 67 is arranged in the cistern 11. The brine (or otherwise a suitable, frost-proof Medium) of a heat pump 24, the consumer circuit is designated 22, 23. (Details of such a heat pump system are explained in more detail below with reference to FIG. 8). The brine cooled in the heat pump evaporator, not shown, which emerges from the heat pump at 21, is pumped through the heat exchanger 67 by a circulation pump, also not shown. As is shown in particular in FIGS. 2a-2c, the heat exchanger 67 is constructed from two segments or modules which consist of a multiplicity of heat exchanger elements 70. Each of these heat exchanger elements comprises a flow header 71, which is connected to a return header 72 by a series of parallel tubes 68. The pipes 68 are bent in a U-shape, so that the pipes leading to the return collectors 72 are arranged between adjacent rows of pipes starting from flow collectors 71. If the cistern water has cooled to a temperature near the freezing point, which is particularly the case when using the latent heat of the cistern contents, ice layers will form on the pipe parts near the inlet header 71, where the brine has the lowest temperature.

The icing continues along the tubes 68. The areas near the return collectors 72 remain ice-free the longest. This measure ensures that no massive ice block forms on the collectors, which due to its relatively small surface area can then only be defrosted with difficulty. The layers of ice adhering to the tube bundles are rather relatively large

Surface and can, as soon as they are washed around by a little warmer water, thawed quickly, which improves the performance of the system again. The total surface of the heat exchanger tubes 68 is dimensioned such that an acceptable coefficient of performance of the system can still be achieved even with moderate icing (ice thickness <5-6 mm). With such an interpretation the

Heat transfer is primarily determined by the thermal conductivity of the ice layer and not so much by that of the pipe material. In addition to the metallic materials often chosen for heat exchangers, plastics such as polypropylene or polyethylene are also suitable in the present case. If the roof skin 1 is warmer than the cistern water, the circulation pump 15 remains in operation and pumps water from the cistern onto the roof surface. The pump 15 is controlled by an electronic control 35, which signals the signals from temperature sensors 33 on the roof skin 1 and from such a sensor 32

Cistern water receives. If, for example, the roof 1 reaches plus degrees in the sun on a winter day and is warmer than the cistern water, the pump 35 is switched on by the controller 35. If the roof skin temperature is below 0 ° C, so that the distributor pipe 5 and partly also the supply pipe 3 could freeze, the pump 15 is switched off. The water in the pipes then flows back through the pump into the cistern.

One advantage of the system according to the invention is that the thermal capacity of the cistern water can be used almost completely: the water can not only be cooled to 0 ° C, one can also use at least some of the latent heat of the water during the transition from the liquid to the solid state , Since this latent heat or melting heat in water is 82 kWh / m ³ , a huge additional energy potential is available with a typical cistern size of 10-15 m ³ .

FIGS. 3 and 4 show two different alternatives to the heat exchanger modules shown in FIGS. 1 and 2, which above all result in better accessibility during assembly and maintenance work. According to FIG. 3, the tubes 68 are arranged along cylindrical surfaces and fed by vertically running flow collectors 71. The return collectors are also vertical.

The tubes 68 are secured in their position by spacers, not shown. As shown schematically in Fig. 5, a number of these vertical axis modules 73 are installed in the cistern. The diameter of the modules is smaller than the clear width of the manhole 74, so that they can be easily retracted during assembly. The pump 15 designed as a submersible pump is arranged in a sector of the cistern 11, 7b denotes the inlet from the roof, 74 is a Filter basket refers to the impurities in the water coming from the roof.

In the variant according to FIG. 3, the modules 73 are of spiral design: the tubes that run horizontally between the vertical flow and return collectors 71 and 72 are first folded in a U-shape and then rolled up in a spiral and secured by spacers (not shown). The assembly in the cistern again takes place according to FIG. 5.

Fig. 8 shows schematically an alternative heating and hot water preparation system for example for a family home. The house has a roof with a roof skin on the side facing the sun (south or west) 1 and on the side facing away from the sun (north or east) 2. The ridge 51 of the roof has so-called. Ridge rider 52, which enclose water distribution pipes 5 and 6. A small section of these tubes 5, 6 is shown in detail in FIGS. 7a and 7b, with FIG.

7a shows a part of these tubes in a top view, while FIG. 7b illustrates a cross section through such a tube. The distribution pipes 5 and 6 are designed as corrugated pipes made of stainless steel or plastic and are slotted at the top or provided with holes so that the water supplied through the pipes 5 and 6 escapes essentially without pressure and finely distributed over the roof skin 1,2 flows below and is finally collected in the gutter 7a. The water is fed to a cistern 11 through rain pipes 7b. With 29 a float arranged in the cistern 11 is designated, which controls an overflow valve and / or a water level indicator (not shown). A counterflow heat exchanger 18 is arranged in the cistern 11 and is constructed coaxially. By the

Inner tube 17 of the heat exchanger 18 circulates the brine (or another suitable, frost-proof medium) of a heat pump 24. The brine cooled in the heat pump evaporator, not shown, which emerges from the heat pump at 21, is circulated through the inner tube 17 of the heat exchanger by a circulation pump 16 pumped. The tube 17 is encased by a coaxial, outer tube through which rainwater draws in rainwater from the cistern 11 through a circulating pump 15 Countercurrent cooler 18 is cooled and finally fed to the distribution pipes 5 and 6 via lines 3 and 4. The rainwater of the secondary circuit can assume a temperature of 0 ° C at the outlet of the heat exchanger 18 under certain conditions, in extreme cases this temperature can even fall slightly below. If the heat pump is not in operation, but the roof skin 1, 2 is warmer than the cistern water, the circulation pump 15 remains in operation and pumps water from the cistern onto the roof surfaces. The pump 15 is controlled by an electronic control 35, which receives the signals from temperature sensors 33, 34 on the roof skin 1 or 2 and from such a sensor 32 in the cistern water. If, for example, on a cold winter day, the roof 1 is in the sun and reaches a few plus degrees, while the roof 2 lying in the shade is in the frost area, the motor-operated valve 27 b is closed by the controller 35. If the roof skin temperature on both roof halves is in the region of the temperature of the cistern water or below, the pump 15 is stopped, so that the pipes 3, 4 and 5, 6 are at least partially emptied by the pump 15.

If the roof skin temperature on both roof halves 1, 2 is below 0 ° C., so that the distribution pipes 5, 6 and in some cases also the supply pipes 3, 4 could freeze, both valves 27a and 27b and the drain valve 28 are opened. The water in the pipes flows back into the cistern. In the event of snowfall or if a layer of snow has already accumulated on the roof, the pump 15 can be activated by actuating a manual switch 36. The valve 28 is closed and the valves 27a, 27b remain in the open position or are brought into this. Preferably, the heat pump 24 is switched off during the defrosting process, so that cistern water and not water cooled by the heat pump is pumped onto the roof. The one between

The roof membrane and the liquid film forming the snow layer causes the snow layer to defrost, so that the roof surfaces are free again. When snow is in progress, defrosting is carried out periodically, keeping the roof free of snow. In order to avoid icing of critical areas within the cistern, a further "cooling operation" can further cool these areas, however, in this case with a reduced coefficient of performance, can be achieved: the medium in the low temperature circuit is heated by a counterflow heat exchanger 19 between the high and low temperature circuit of the heat pump 24. In this operating state, the heat exchanger 19 is connected as a consumer in the high-temperature circuit and is connected on the one hand to the hot water inlet 23 and on the other hand to the hot water return 22. A thermostatic valve 25 inserted into the inlet or return to this heat exchanger controls this "feedback" function of the system. The temperature sensor 26 of the thermostatic valve 25 is fastened to a pipe in the return line of the water of the primary circuit 8, the boiler for the heating system (in particular for a low-temperature heating system such as floors, ceilings and or wall) are shown in Fig. 8 for reasons of clarity ) and for water heating for the bathroom, kitchen, etc. not shown

Finally, FIG. 8 shows a photo-voltaic panel 31 integrated into the roof skin 1, as is marketed for example by PREFA under the name "PREFA-SOLAR". Such photo-voltaic panels have an efficiency, which is strongly temperature-dependent and worsens with increasing temperature. By sprinkling with the comparatively cool cistern water, the panels are cooled and thus their efficiency is increased.

A weatherproof distributor 8 is provided in the rain pipe 7b, via which heat can be extracted from the rainwater of the secondary circuit at two different temperature levels without using the heat pump 24. The corresponding derivatives are designated 9 and 10.

Fig. 9 shows details of the distributor 8. In the rain pipe 7b, a rainwater filter from WISY AG, Haustechniksysteme is used, which in his

Principle is described in DE 20015675U. This filter is based on knowledge that the water flows off along the inside wall of the pipe with a normal water supply. A pipe socket 45 connected to the rain pipe 7b guides the water through a conical fine filter 44. Pure water passes through this so-called. "Adhesion filter" is collected in an annular chamber and discharged through a connection pipe. Coarse impurities, such as leaves 37, fall through the central part of the rainwater filter and go directly into the cistern, where they are collected in a filter basket Water heated to the roof to a thermostatic valve 41, the capillary bulb 39 of which is flushed with the inflowing water, the thermostatic valve 41 is set so that it opens, for example, at a temperature of 30 ° C. Another one is at 42

Thermostatic valve in the discharge line 10, the capillary bulb 40 is also arranged in the connecting pipe. However, this valve is set to a higher temperature and only opens, for example, at a temperature of 50 ° C. The water from the discharge line 9, which has at least a temperature of 30 ° C., is fed to a heat exchanger 47a arranged in a heating boiler 48 and is finally fed back into the rain pipe 7b. The boiler 48 is connected to the supply and return lines 23 and 22 of the heat pump 24 via the connecting pieces 57, 58. For heating purposes of low-temperature heating systems such as floor, ceiling and / or wall heating, water can be drawn off and on again via the connections 59 and 60 be returned. The water coming from the roof reaches one

Temperature of at least 50 ° C, the thermostatic valve 42 also opens and water now flows through the connecting pipe 10 to a heat exchanger 47b, which is arranged in a second boiler 49. The water emerging from the heat exchanger 47b is returned to the cistern via the rain pipe 7b. The boiler 49, on the other hand, is heated by the heat pump 24. For this purpose the

Boiler 49 is connected to the supply and return lines 23, 22 of the heat pump via the connections 55, 56. A second heat exchanger 46 is arranged in the boiler 49, in which drinking water is heated. The rainwater filter is emptied through a by-pass line 43. This by-pass also ensures a corresponding water exchange in the area of the rainwater filter connection pipe, so that the Temperature sensors 39, 40 of the thermostatic valves 41, 42 are always supplied with fresh water. In Fig. 4, 38 denotes a ventilation pipe.

For heating water for heating purposes and hot water preparation, it is advantageous not to sprinkle the roof surfaces continuously with cistern water, but periodically. This means that the roof skin has the option of returning to a higher temperature. In a corresponding test facility, the return temperature of the cistus water could be increased from 15 ° C with continuous sprinkling to 35 ° C with periodic operation, whereby the amount of water generated was naturally reduced.

The invention is not limited to the example described above, but rather can be modified in numerous respects without leaving the scope of the invention.

Claims

1. heating and / or hot water preparation system using a heat pump (24), with an external coolant circuit with a heat exchanger (18) which is washed by water from a rainwater cistern (11) or the like and is arranged sunk in this, in Which heat exchanger (18) from the heat pump (24) warms cold medium and is returned to the heat pump (24), whereby if the cistern (11) is submerged in the ground, the cistern water extracts heat from the surrounding ground by heat exchange through the wall of the cistern and thus the water warms up again, a pump (15) being provided, with which water can be conveyed from the cistern (11) onto a roof (1, 2), where it is distributed in the upper area of the roof surface by means of distribution pipes (5, 6), in particular evenly, is distributable and the water flowing over the roof skin can be collected in gutters (7a) and returned to the cistern (11), characterized in that the heat exchanger (18 ) is made up of a series of segments, each with a flow and a return manifold, which are connected to each other by the actual tubular or plate-shaped, essentially parallel heat exchange elements and washed around by the cistern water and through which the coolant of the heat pump (24) can flow the adjacent heat exchanger segments can be flowed through in opposite directions and the flow and return collectors of the adjacent segments are arranged directly next to one another, furthermore with an electronic control (35) in particular, which is dependent on signals from temperature sensors (32 to 34) on the roof surface (1, 2), in the cistern (11) and / or in lines controls the pump (15) and any valves (27a, 27b, 28), so that water from the cistern (11) onto the roof (1 , 2) conveyed, heated there and into the cistern (11) is recyclable, if there is a risk of freezing of the water in the distribution pipes (5, 6) or on the roof skin (1, 2) the pump (15) and valves (27a, 27b, 28) can be controlled in such a way that the water is conveyed to Roof is interrupted and the distribution pipes (5,6) and possibly also their supply lines (3,4) are emptied and preferably the pump (15) for circulating the water in the cistern (11), so that the heat capacity of the water of the cistern (11) including at least part of the latent heat thereof and, if appropriate, the geothermal energy supplied through the cistern wall can be used.

2. Heating and / or hot water preparation system according to claim 1, characterized in that the heat exchanger elements consist of a plurality of, preferably made of plastic or metal pipes, which are folded approximately in the middle, so that the adjacent areas of the heat exchanger elements can flow in opposite directions.

3. Heating and / or hot water preparation system according to claim 1 or 2, characterized in that the in particular folded heat exchanger elements are spirally rolled and shaped into cylinders whose diameter is smaller than the entrance to the cistern, these cylindrical heat exchanger segments preferably being fastened in the cistern with a vertical axis are.

4. Heating and / or hot water preparation system using a heat pump (24), with a first, external coolant circuit with a heat exchanger (18) which is fed by water from a rainwater cistern (11) or the like, in which heat exchanger ( 18) coming from the heat pump (24), the cold medium is heated and returned to the heat pump (24), whereby if the cistern (11) is submerged in the ground, the cistern water extracts heat from the surrounding ground by heat exchange through the wall of the cistern and thus warms the water again and a pump (15) is provided, with which water can be conveyed from the cistern (11) onto a roof (1, 2), where it can be distributed, in particular evenly, in the upper region of the roof surface and the water flowing over the roof skin in Gutters (7a) can be collected and returned to the cistern (11), characterized in that the heat exchanger is designed as a countercurrent heat exchanger (18) which can be flowed through by the medium from the evaporator circuit of the heat pump (24) on the one hand and by the water from the cistern on the other cooled cistern water emerging from the heat exchanger (18) can be conveyed via a valve (27, 27b) to the distributor pipes (5, 6) on the roof (1, 2) and can be finely distributed over the roof surface, a connecting line (14) with a valve (28) is provided between the supply line (3, 4) to the distribution pipes (5, 6) and the cistern (11), which is upstream of the valve (27a, 27b) in the supply line (3, 4) to the distribution pipes (5 , 6) opens, further with a in particular electronic control (35) which, depending on signals from temperature sensors (32 to 34) on the roof surface (1, 2), in the cistern (11) and / or in lines, the pump (15) and the valves (27a , 27b, 28) controls, so that in normal operation water is pumped from the cistern (11) onto the roof (1, 2), heated there and can be returned to the cistern (11) when there is a risk of freezing the distribution pipes (5,6 ) and the roof skin (1, 2), the valves (27a, 27b, 28) and the pump (15) are controlled so that the cistern water cooled in the counterflow heat exchanger (18) via the opened valve (28) directly into the cistern (11 ) is traceable, so that the heat capacity of the water in the cistern (11) including at least part of the latent heat thereof and, if appropriate, the geothermal energy supplied through the cistern wall can be used.

5. Heating and / or hot water preparation system according to one of the preceding claims, characterized in that the roof skin (1, 2) consists of sheet metal, preferably of aluminum sheet and has a surface coating with a high absorption capacity in the visible and in the infrared range of the spectrum.

6. Heating and / or hot water preparation system according to one of the claims 1 to 5, characterized in that in particular along the roof ridge (51), a horizontally extending distributor pipe (5,6) with a plurality of water outlet openings (53) arranged along the pipe. is provided, through which the roof skin (1, 2) can be sprinkled substantially uniformly, a corrugated pipe (5, 6) made of corrosion-resistant metal or plastic, which has slots or bores (53) on its top, being provided as the distributor pipe which the cistern water emerges essentially without pressure.

7. Heating and / or hot water preparation system according to one of the claims 1 to 5, characterized in that the in particular along the roof ridge distribution pipes at their end facing away from the feed each have a vertical, open pipe socket, the pressure with which the Pump conveys the cistern water to the roof, can be adjusted by means of throttles so that the vertical pipe sockets are partially filled with water during operation and the distributor pipes have a large number of bores on their underside, the distributor pipes preferably with a slight slope towards the Are mounted on the roof, so that the manifolds are completely emptied during the breaks.

8. Heating and / or water heating system according to one of claims 6 or 7, characterized in that the distributor pipe or the distributor pipes (5, 6) are integrated in ridge riders (52).

9. Heating and / or hot water preparation system according to one of the preceding claims, characterized in that photo-voltaic panels (31) are integrated in the roof skin, which can be sprinkled by the water conveyed from the cistern (11) and thus cooled, and thereby achieve a lower efficiency.

10. Heating and / or hot water preparation system according to claim 4, characterized in that the counterflow heat exchanger (18) is constructed as a coaxial, double-walled tube, wherein the inner tube through which the primary circuit flows can be flowed around by the cistern water of the secondary circuit, which is in the space between the inner and outer tubes is guided, wherein the counterflow heat exchanger (18) is preferably arranged sunk in the cistern (11).

11. Heating and / or hot water preparation system according to one of the preceding claims, characterized in that in the return line of the heat pump (24) a further heat exchanger (19), in particular. A counterflow heat exchanger is provided, which via a valve (25) from the high temperature circuit Heat pump (24) (consumer circuit) can be fed, the valve (25) being controllable by a temperature sensor (26) via an electrical control (35), which sensor (26) is arranged, for example, in the cistern water and, if the temperature falls below a predetermined value, the valve (25) opens and supplies a partial flow of the medium from the high-temperature circuit of the heat pump (24) to the aforementioned heat exchanger (19).

12. Heating and / or hot water preparation system according to one of the preceding claims, characterized in that in the return line from the sprinkler roof surface at least one actuatable depending on the temperature of the water of the return line of the secondary circuit valve (41,42) is provided, which in Circle of one heat exchanger (47a, 47b) is arranged and the valve (41,42) then opens regardless of the operation of the heat pump (24) and the water of the return line via the heat exchanger (s) (47a, 47b) into the cistern (11 ) conducts when the predetermined switching temperatures of the valves (41, 42) are reached or exceeded, the heat exchangers (47a, 47b) being surrounded by water from the associated boilers (48, 49).

13. Heating and / or hot water preparation system according to claim 12, characterized in that a rainwater filter, preferably a so-called. Adhesion filter (43 to 46) is provided, through which filtered return water can be fed to the heat exchanger (47) via the valve (41, 42), while coarse impurities such as leaves (37) etc. can be fed directly to the cistern (11) and held there with sieves and / or filters ..

14. A method for operating a heating and hot water preparation system with a water container, for example with a cistern (11), for storing hot water and a device preferably arranged on a roof (1, 2) for heating the water using the entire environmental energy, wherein A heat exchanger (47a, 47b) is preferably provided in the return line (7a, 7b) of the heated water coming from said device, through which water can be heated for various consumers such as heaters, heat pumps, baths and swimming pools, characterized in that the water tank, in particular the cistern (11) is initially filled with preferably rain water and this water is heated via a heat exchanger (18), in particular via a countercurrent heat exchanger, in which the cold brine or the like coming from a heat pump (24) is heated and in normal operation by means of a pump or the like (15), if necessary, periodically guided onto a roof (1, 2) and then finely distributed on this, the water heated on the roof skin (1, 2) being collected in a rain gutter (7a) and is returned to the water tank (11).

15. A method for operating a heating and hot water preparation system according to claim 14, characterized in that when there is a risk of freezing of the water, in particular at roof skin temperatures below 1 ° C, the distributor pipes (5,6) and the feed lines (3, 4) are emptied and through the heat exchanger is withdrawn from the cistern water and in this operating state the thermal capacity of the cistern water including at least part of the latent heat thereof and, when the cistern is sunk in the ground, the heat supplied by the geothermal energy of the cistern (11) for heating the brine or the like of the heat pump (24) is used.

16. A method for operating a heating and hot water preparation system according to claim 14 or 15, characterized in that in summer operation, in particular when the heat pump (24) is switched off, the feed pump (15) is switched on, the running over the roof skin (1, 2), cooler cistern water directly and additionally by evaporation cooling the roof (1, 2) and when the cistern (11) is buried in the ground, the comparatively warm cistern water heats up the surrounding soil, which is additionally available in heat pump mode to heat the cistern water ,

7. The method for operating a heating and / or hot water preparation system according to one of the claims 14 to 16, characterized in that the sprinkling of the roof surface can be switched on via a manually operated switch (36) or via a snow sensor, so that when there is snow or Snowfall deliberately triggered the avalanche of roof avalanches or, in the event of snowfall, the snow is immediately defrosted and the roof (1, 2) is thus cleared of snow.