DE29816006U1 - Home or space heating system with heat storage - Google Patents

Description

House or room heating system with heat storage

The invention is based on a house or room heating system in connection with a domestic hot water supply system, according to the preamble of claim 1.

Since heat energy obtained from electrical energy is usually several times more expensive than heat generated from natural gas or heating oil, the oil or gas boiler in a central heating system or district heating is used to heat domestic water, especially in private households.

In view of advanced thermal insulation measures in the home and the corresponding boiler regulations, modern boilers are extremely small. For a well-insulated single-family home, a boiler output of 5-10 kW is sufficient. However, for heating domestic water, which on average only accounts for around 20% of the total heat requirement of a household, peak outputs of around 30 kW are required, e.g. for showering or bathing. During such peak outputs, a central heating boiler with a small capacity is overwhelmed (see Fig. 3). For this reason, it is common to provide a hot water tank for the preparation of hot domestic water.

Various designs of stratified storage tanks 2 <Fig. 4) and storage charging systems 4 <Fig. 5> are used as hot water storage tanks.

The stratified storage tank 2 (Fig. 4) consists of a thermally insulated, pressure-tight water tank 6, which has a connection to the water pipe β in its lower area and an outlet in the upper area for feeding the various hot water taps 10. The water in the storage tank 2 is heated by an internal pipe coil 12, which is connected parallel to the heating circuit to the heating boiler 14 or to the district heating network. If the heating of the domestic water 16 using the heating boiler 14 is not sufficient or during the summer, when the heating boiler 14 is completely switched off, an optional additional electric heater 18 based on the immersion heater principle can be provided. Since the domestic water 16 is permanently kept warm, there is a risk of legionella formation. A further disadvantage is the numerous long hot water pipes from the central stratified storage tank 2 to the individual hot water taps 10 as well as a circulation system consisting of circulation pipes and a circulation pump, which functions constantly and causes heat losses.

As an alternative to the stratified storage tank 2, storage charging systems 4 are known. Here, there is also a thermally insulated, pressure-tight container 20 as a storage tank for the hot domestic water 16. This container 20 also has a connection to the water pipe 8 in its lower area and an outlet in the upper area for feeding the various hot water taps 10.

The domestic water in the storage tank 20 is not heated by an internal pipe coil but by means of an external heat exchanger 22 connected to the boiler 14 or to the district heating network <Fig. 5).

Here too, there is a risk of legionella formation. The long hot water pipes and circulation pipes between the central domestic water tank 20 and the various decentralized hot water taps 10 have also proven to be disadvantageous.

A heat recovery device is also commercially available which generates hot water of around 50 - 60 ⁰ C from the waste heat of cooling systems. This heat recovery device consists of a water tank which is surrounded on the outside by a spiral-shaped double pipe. The tank is connected to the cold water pipe. As soon as a connected refrigeration machine is running, the cold water flows out of the tank into the inner annular space of the double pipe and is heated in countercurrent to the coolant which flows through the outer annular space.

A precisely reproducible layering of the heated water in the tank during both loading and unloading does not seem possible. Both the cladding tube and the inner tube must be designed to be pressure-stable. To ensure optimal heat transfer, spacers must be installed between the two tubes. This makes production considerably more expensive. Since the exchanger tube is located outside the tank, additional and/or complicated thermal insulation is required for the double tube.

The present task is to create a storage device that does not have the disadvantages mentioned above.

This task is essentially related to the characteristics of the
The main claim is resolved. The subclaims give
advantageous details and further training.

The arrangement of the heating system provided with hot water supply according to the invention has, in contrast to the
usual arrangements no domestic water storage but
a heating storage tank, the storage capacity of which is available to both the heating system and the domestic water system.

This means that peak performance can be achieved both in
Heating system as well as domestic water system covered
Since no hot water is stored in the tank, there is no risk of infection by
Legionella formation.

The domestic water is heated near the respective tap, so that there is no water loss and
There are no downtime losses, as is the case with the usual long
Water pipes between central domestic water storage
and decentralized taps are otherwise unavoidable.

The circulation system normally used in domestic water systems is completely eliminated here. In order to heat the heat exchanger of the
To supply the water heater with warm water, circulation is only required in summer, as the taps are constantly supplied with hot water during winter heating operation.
Water can be available immediately.

Preferably, the memory according to the invention is a
Heat exchanger storage tank designed as a buffer storage tank, which consists of a storage tank with internal

Countercurrent charging device.
Countercurrent principle is an optimal
Heat transfer is achieved.

A particularly cost-effective solution is obtained if the countercurrent device consists of a pipe coil that runs through the storage tank, which is part of the primary heating circuit and is surrounded as an inner pipe by a jacket pipe coaxially, whereby the jacket pipe is flowed through by storage water in a countercurrent process if required.

If the last (top) pipe loop of the jacket pipe is perforated for the purpose of hot water outlet, a temperature stratification is easily achieved. Such a temperature stratification, which increases from bottom to top, can be optimized if returns of different temperatures are introduced into the tank via pipe sockets of different lengths, with baffles preventing the introduced return water from mixing with the remaining storage water.

The essential core of the invention is the arrangement of the countercurrent heat exchanger in the heating water tank, specifically for the purpose of precise stratification both when loading from top to bottom and when discharging from bottom to top. According to the invention, this is carried out by a special cladding tube arrangement in the tank with an opening at the top. This achieves precise stratification. Another advantage of the invention is that the cladding tube does not have to be designed to be pressure-stable.

There is also no need for exact spacers between the inner and outer pipes, because both pipes are made of corrugated pipe, the inner one is pressure-resistant, the outer one is not. The corrugations of both pipes allow the

the annular gap flow follows its path and is caused by the external turbulence to achieve a good heat exchanger effect.

The cladding tube can therefore preferably be made of a thin-walled plastic material and can thus be manufactured cheaply, so that the specific arrangement and design of the known tube-in-tube exchanger principle creates three advantages according to the invention:
1. Exact stratification in the buffer tank or storage tank, both during loading and unloading.

2. Cheapest design of the counterflow exchanger sleeve pipe due to thin walls and no spacers.

3. Energy benefits because of the internal Rohi-in-Rohi principle and therefore no additional insulation is necessary.

In order to make the best possible use of the energy available, particularly in district heating networks, the district heating return temperature can be limited using a thermocouple. 20

An immersion sensor near the return inlet checks whether the temperature and thus the charge of the storage tank has not fallen below a specified setpoint.

The memory according to the invention is explained in more detail below with reference to the attached drawings.

Fig. 1 shows the arrangement of the storage tank in a heating system;
Fig. 2 shows the structure of the storage tank in longitudinal section; Fig. 3, Fig. 4 and Fig. 5 show heating systems according to the state of the art;

Fig. 6 shows a schematic diagram of a heating system with a domestic hot water storage tank.

Värnie exchanger storage j

Fig. 7 shows a heating system in which a heat exchanger storage tank serves as a buffer storage tank; Fig. 8 and Fig. 9 show heating systems each with a heat exchanger storage tank, in which the heat exchanger storage tanks each have two heat exchangers.

A conventional central heating system essentially consists of a heat source (e.g. boiler 14 or district heating), the radiators 26 installed in the individual rooms and the pipe network including circulation pump 28, through which the radiators 26 are supplied with warm heating water 30 from the boiler 14.

The hot water tank 24 according to the invention is not used to store hot domestic water 16 but to store heating water 30. For this purpose, a pipe coil 36 connected to the heating boiler 14 via flow 32 and return 34 is located within the thermally insulated and pressure-tight container (buffer tank) 24 according to the invention. The heating boiler 14, pipe coil 36, flow 32 and return 34 together form a primary circuit 38, which is driven by a circulation pump 28. A thermocouple 40 for limiting the (district heating) return temperature is installed in the return 34 of the primary circuit 38.

The pipe coil (pipe spiral) 36 located in the container 42 of the buffer tank 24 is coaxially surrounded by a second pipe 44. The last (uppermost) pipe loop 46 of this jacket pipe 44 is perforated. The lower end of the jacket pipe 44 is connected to the container interior 52 via an external pipe loop 50 provided with a circulation pump (charging pump) 48.

While the primary heating circuit 38 is guided from top to bottom through the storage tank 42, the water guided through the jacket pipe 44 circulates according to the countercurrent principle in the opposite direction from bottom to top along the inner pipe coil 36 until it passes through the perforation in the last pipe loop 46 into the upper part of the storage tank 42.

In the upper area of the storage tank 42 there is an outlet which forms the flow 54 of a secondary heating circuit. The return 56 passes through the floor through pipe sockets 68 of different heights and provided with baffles 66 for introducing returns of different temperatures into the storage tank (e.g. from radiator circuits and from circuits for underfloor heating). The warmer return water is introduced into the tank at a higher level than the colder return water.

In the lower area of the tank interior 52, near the return flow inlet, there is an immersion sensor 58 for controlling the charging pump 48.

The secondary heating circuit 62, like the primary circuit 38, has a circulation pump 60.

The radiators 26 are connected to the secondary circuit 62. One or more domestic water heat exchangers (instantaneous water heaters) 22 are installed parallel to the heating circuits, with the secondary heating circuit 62 connected on the primary side and the tertiary domestic water circuit 64 (water source, tap 10) connected on the secondary side. This means: With the arrangement according to the invention, it is not warm domestic water - as is usual - that is stored, but warm heating water.

The heating system shown in Fig. 6 contains a heat exchanger storage tank 24 according to the invention as an "inline countercurrent stratified loader" for domestic water storage. A heating boiler (e.g. a condensing boiler) 14 is connected via a mixer 70 to both a heating circuit 72 (radiator 26) and a heat exchanger storage tank 24.

The countercurrent heat exchanger of the storage tank consists of a trapezoidal tube as the inner tube 36 for heating water and a coaxial, top-open plastic corrugated tube as the countercurrent casing tube 44. Because drinking water is to be pumped, the countercurrent pump 48 is made of bronze.

In the lower part of the storage tank there is a cold water inlet. In the upper part of the storage tank there is a pipe socket for hot water extraction. The incoming cold water presses in countercurrent into the casing pipe 44 so that it now comes out at the very top as hot water. This ensures constant stratification in the storage tank and a high return cooling in the charging heating circuit. The charging is controlled by two thermometers: one when the cold water inlet is around 50 liters, one when the hot water filling is around 100 liters.

In contrast to the system shown in Fig. 6, Fig. 7 shows a buffer storage tank 24 according to the invention. This storage tank does not store warm domestic water but heating water heated by a boiler 14. The heating water from the boiler 14, which is designed as a condensing boiler, flows directly into the buffer storage tank 24 according to the invention without a mixer. The domestic water is heated therein using the countercurrent principle. A flow rate regulator 74 ensures that a

- &iacgr;&ogr; -

Countercurrent heating of the domestic water only occurs when hot water is drawn off. The heating system consists of an unmixed heating circuit 76 and a heating circuit 78 mixed via a mixer 70 (e.g. for underfloor heating).

Fig. 8 shows a comparable system with a condensing boiler serving as a heating boiler 14, which transfers the warm feed water directly to the buffer tank 24 according to the invention, an unmixed heating circuit 76 and a circuit 78 mixed via a mixer 70. Here too, the heating of the domestic water is achieved using a double pipe coil in the countercurrent principle. In addition, this buffer tank 24 has another double pipe coil with an inner pipe 36 and a coaxial jacket pipe 44 open at the top. The water heated in a solar collector 80 flows through the inner pipe from top to bottom, while the storage water in the buffer tank 24 flows through the jacket pipe from bottom to top in the countercurrent principle, taking on the heat introduced by the solar collector 80.

In the system shown in Fig. 9, the buffer storage tank 24 according to the invention also contains two double pipe coils, namely a double pipe coil for transferring district heating from a district heating supply line 82 to the buffer storage tank 24 and a second double pipe coil for transferring the heat from the buffer storage tank 24 to a hot water pipe. Here too, a flow rate regulator 74 ensures that domestic water heating only takes place when hot domestic water is required.

House or room heating system with heat storage List of reference symbols

2 layer storage

4 Storage charging system

6 tanks of the stratified storage

8 Water pipe

10 Tap

12 Pipe coil

14 boilers

16 Domestic water

18 Additional heating

20 storage tanks of the storage charging system

22 heat exchangers

24 inventive memory,

Heat exchanger storage, buffer storage

26 radiators

28 Circulation pump

30 Heating water

32 Heating flow, primary

34 Heating return, secondary

36 Pipe coil, pipe spiral, inner pipe

38 Primary circuit

40 Thermocouple

42 Buffer tank, storage tank, storage

44 coaxial jacket pipe

46 perforated top pipe loop

48 Circulation pump (charging pump), pump element, countercurrent pump

50 external pipe loop

52 Container interior

54 secondary heating flow

56 secondary heating return

58 immersion sensors

60 Circulation pump

62 Secondary circuit

64 tertiary circuit (domestic hot water circuit), domestic hot water

66 Baffle plate

68 pipe sockets

70 mixers

72 Heating circuit

74 Flow regulators, flow regulators

76 unmixed heating circuit

78 mixed heating circuit

80 solar collector

82 District heating supply, district heating network

Claims (11)

Protection claims 1. House or space heating system, &zgr;. &Bgr;. Central heating system, with heat storage in storage tanks, in connection with a domestic hot water supply system, characterized by a primary <38) and a secondary heating circuit (62) and a tertiary domestic water circuit <64>, whereby a heat exchanger with an integrated secondary-side storage tank (heat exchanger storage tank 24) is arranged between the primary (38) and secondary heating circuit <62> and a heat exchanger <22) is arranged between the secondary heating circuit <62) and tertiary domestic water circuit <64). 2. House or room heating system according to claim 1, characterized in that the heat exchanger storage tank <24) is a buffer storage tank, which consists of a storage container <42) with at least one internal countercurrent charging device. 3. House or room heating system according to claim 2, characterized in that the countercurrent charging device consists of a pipe coil <36) passed from top to bottom through the storage tank <42>, which is part of the primary heating circuit (38), and wherein the pipe coil <36) is surrounded as an inner pipe coaxially by a jacket pipe <44), which, depending on the control of an active pump element <48), is flowed through by the water <30) of the storage tank <42> from top to bottom or from bottom to top. 4. House or room heating system according to claim 2 or 3, characterized in that the uppermost (last) pipe loop (46) of the edged pipe <44> is perforated for the purpose of hot water outlet or is open at the upper inner edge of the container, whereby the jacket pipe <44) is open towards the interior (52) of the tank <42) in the upper tank area for the purpose of heating water outlet and whereby the heating water (30) in the edge pipe (44) is in static pressure equalization with the heating water storage tank (42). 5. Heat exchanger storage for a house or room heating system, with a heating circuit and with a domestic water circuit, wherein the heat exchanger storage tank <24) is a buffer storage tank connected to the heating circuit, which consists of a storage tank <42) with an internal countercurrent charging device, and wherein the countercurrent charging device comprises a pipe coil <36) which is led through the storage tank <42) and is part of the domestic water circuit, and wherein the pipe coil (36) is surrounded as an inner pipe coaxially by a canted pipe <44), characterized in that the pipe coil <36) runs from top to bottom through the storage tank (42), whereby the domestic water flows from bottom to top through the pipe coil <36> as required, and the heating water flows through the edged pipe <44> in the countercurrent principle as required, The uppermost (last) pipe loop <46) of the dumbbell tube <44) is perforated for the purpose of hot water outlet. - 13 - 6. Heat exchanger storage according to claim 5,
characterized, that in the storage tank <42) in addition to the countercurrent exchanger device consisting of a pipe coil <36) and a jacket pipe <44) for domestic water heating, there is a further countercurrent exchanger device consisting of a further pipe coil and a further
Countercurrent exchanger device for the jacket pipe
Stratified charging of the storage tank <42> from solar energy
is located, The solar-heated medium in the inner tube flows from top to
below through the reservoir <42). 7. Heat exchanger storage according to claim 5,
characterized, that in the storage tank (42), in addition to the countercurrent exchanger device consisting of a pipe coil <36> and a jacket pipe <44) for heating domestic water, there is a further countercurrent exchanger device consisting of a further pipe coil and a further
Counterflow exchanger device consisting of a jacket pipe for the purpose of receiving district heat from a district heating network <82>
is located. 8. Heat exchanger storage according to one of claims 5 to 7, characterized by a proportional flow control pump unit, - for the required, proportional control of the heating water (30) flowing through the jacket pipe <44) depending on the quantity of domestic hot water requested
<64). - 14 - 9. Heat exchanger storage tank according to claim 8, characterized in that the flow regulator pump unit serves as an alternative to the hot water heating circuit supply, the flow regulator (74) having a priority circuit, - for temporarily switching off the heating circuit during the domestic hot water requirement. 10. House or room heating system according to one of claims 1-0 2-9, characterized in that the inner tube (36) of the Countercurrent exchanger device<en) is a corrugated metal pipe, and that the jacket pipe <44) consists of thin-walled plastic and is always guided from top to bottom in the inner area of the container <42>, whereby it is always open in the upper area and in the lower area of the container <42) always opens onto an inner container nozzle, which as a stable pipe element accommodates the active countercurrent pump <48) between its two passages in the container bottom, and whereby the precisely layered loading and unloading of the container <42> is brought about solely by changing the flow direction in the jacket pipe (44) by means of an active conveying element (48). 11. House or room heating system according to one of the preceding claims, characterized in that a thermocouple <40) for limiting the (district heating) return temperature is arranged in the return flow <34) of the primary circuit <38).