DE9017667U1 - Heating arrangement with at least one heat generator and parallel-connected storage tanks for heating water and hot water - Google Patents

Description

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Heating system with at least one heat generator and parallel-connected storage tanks for heating water and hot water

The subject of the present innovation is a heating arrangement with at least one heat generator, which is connected to a buffer storage tank in order to reduce the burner cycles, whereby the buffer storage tank is connected on the one hand between the flow and return of the heat generator and on the other hand between the flow and return of the heating circuit in the manner of a heating water buffer.

A heating arrangement mentioned above with at least one heat generator, which is connected to a buffer storage tank to reduce the burner running times, is already known from EP 0 122 475 A1.

It has already been recognized there that in order to reduce the number of burner starts, it is necessary to connect a heat generator (e.g. an oil or gas boiler) with a relatively small water content to a buffer tank with a larger water content in such a way that the buffer tank is arranged between the heat generator and the heating circuit.

This has the advantage that over the operating period only relatively few burner starts are required, each of which results in high soot emissions and the emission of other poisonous gases.

The disadvantage of the known heating system, however, is that the buffer tank is only connected in the bypass to the heat generator and not directly between the heat generator and the heating circuit. This results in a relatively complicated piping system.

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with a high level of control effort to control the bypass flow depending on the different operating states of the system.

Furthermore, the heating system mentioned cannot ensure that the boiler is always kept free of the cold heating water flowing back from the heating system's return line. This has the disadvantage that deposits build up in the boiler and condensation on the heat exchanger surfaces cannot be prevented.

According to the OE-Z: WBnTirterhrriic S/V987, pages 331 to 334, it is also already known to connect a buffer storage tank in parallel to a heat generator. However, the known heating arrangement draws the heating water for operating the heating system and the hot water for domestic water production from one and the same buffer storage tank, so that disadvantages can arise here if there is a strong drop in temperature in the heating or domestic water area, which both originate from one storage tank.

The innovation is based on the task of further developing a heating arrangement of the type mentioned at the beginning in such a way that, while improving the efficiency, even longer burner running times and a further reduction in the pollutant emissions of the heat generator are ensured.

The solution to the problem is achieved by the technical teaching set out in claim 1, which essentially consists in that in addition to the buffer storage for heating water, a further storage tank for domestic water or for hot water is connected in parallel to the heat generator, so that a uniform combination storage tank is present in the form of the heating water buffer and the hot water storage tank.

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This has the advantage that in all operating states the heat generator is always flowed through by preheated water from the buffer tank and that a buffer is also formed in relation to the domestic water or hot water. This ensures that the colder water flowing back from the heating circuit only reaches the buffer tank and not the heat generator, and that access by domestic water refers to the domestic water tank and not to the heat generator, whereby the latter is protected from direct heat fluctuations.

This results in considerably longer burner running times of, for example, 1 hour before I ¹ hour before, whereby this time is essentially due to the new control system and the difference in the volume of the buffer tank or hot water tank compared to the volume of the heat generator.

Another key feature of this innovation and the hot water storage tank is the connection of the heat generator with the buffer storage tank mentioned above with a heat pump circuit, which in turn contains another buffer storage tank.

The combination of this heat pump circuit with the buffer storage tank assigned to it in conjunction with the buffer storage tank of an oil or gas boiler or the parallel hot water tank for domestic water results in further significant advantages.

This proposes a standardized heating arrangement, the most important components of which are prefabricated as modules, which ensure partial removal, later retrofitting or pipework adjustment at any time.

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The main advantages of such a modular system are as follows:

1. Significantly longer running time of the oil burner or heat pump. This means reduction in pollutant emissions and less wear and tear on the equipment.

2. This mode of operation is also beneficial for the chimney, as it means that fewer condensation problems occur.

3. There is less residue in the boiler - from the build-up of dirt - because it runs for a longer time at a higher temperature. This mode of operation also has a positive effect on the life of the boiler.

4. Over a relatively long period of time (transition period and influence of external heat) with a two-pipe heating system, there is a situation where only a small amount of heat (amount of water) is taken up, which also results in a larger temperature spread. This also has a negative effect on the boiler. A system in the low-temperature range or underfloor heating is just as problematic for the boiler. With this solution, the relatively cold return water goes into the buffer tank and not directly into the boiler. When the boiler is heated up, the return is very quickly at normal temperature. (Temperature mixing in the tank). Likewise, the withdrawal of domestic water does not have a direct effect on the heat generator.

The subject matter of the present innovation arises not only from the subject matter of the individual protection claims, but also from the combination of the individual protection claims with one another.

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All information and features disclosed in the documents - including the summary, in particular the spatial configuration shown in the drawings, are claimed as essential to the invention.

In the following, the innovation is explained in more detail using drawings that only show one implementation method. The drawings and their descriptions reveal further key features and advantages of the innovation.

Figure 1: schematically shows a heating arrangement according to the innovation;

Figure 2: Top view of the components of the heating arrangement according to Figure

A heat generator 2, which is designed as an oil or gas boiler, works with its flow line 18 on a three-way valve S2, into which the flow line 20 of a heat pump 1 also flows.

The output of the three-way valve S2 is formed by a line 22, in which a pump Pl is switched on, which operates via a line 23 on a second three-way valve S3.

A line 11 branches off from the three-way valve S3 as a supply line for a buffer tank 8 and a line 16 as a supply line for a heat exchanger 15 of a domestic hot water tank 3.

In the buffer tank 8, a chicane 9 - shown only schematically - is arranged on the flow side, which ensures that the warmer water entering the buffer tank 8 is evenly distributed in the buffer tank 8.

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The line 12 of the buffer tank 8, which forms the return flow, opens into an immersion pipe 10 in the bottom area of the buffer tank 8, so that it is ensured that only the colder water collecting in the bottom area leaves the buffer tank 8 via the line 12.

The output of the buffer memory 8 is formed by a line 13,

which opens onto a three-way valve Sl, which also has a

Attach the bypass line 30 and the line 31 which forms the flow for the heating circuit.

The return of the heating system is formed by the line 32, from which the passage 30 branches off and which then passes into a line 14, which leads the colder water returning from the heating circuit into the bottom area of the buffer tank 8.

A domestic hot water storage tank 3 is connected in parallel to the buffer tank 8, the heat exchanger 15 of which is supplied on the inlet side via the line 16 by the three-way valve S3 and the outlet side of which flows into the return line 19 of the heat generator 2 via the line 17.

A heat pump system is connected in parallel to the previously described heat generator 2 with the buffer storage tank 8 and the heat exchanger 15 of the domestic hot water storage tank, which in turn has a buffer storage tank 4.

The flow line 20 of the heat pump 1 flows into the three-way valve S2. The return line 21 of the heat pump 1 is connected to the return line 19 of the heat generator 2.

The absorber circuit of heat pump 1 is made up of the following parts:

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In the return line of the heat pump 1, a line 24 is arranged which leads to a pump P4, which pumps the brine into the bottom area of an absorber 7.

The brine is heated by solar radiation and leaves the absorber on the upper side via a line 25, which leads into a three-way valve S4. The outlet of the three-way valve S4 is formed by a line 26, in which a pump P3 is switched on, which flows into the heat pump 1 via a line 27.

Parallel to the return of the heat pump 1, namely to the line 24, a flow meter is provided which forms the property of the heat exchanger 4a arranged in the buffer tank 4.

The outlet side of the heat exchanger 4a is formed by the line 28, which opens into the three-way valve S4.

The arrangement of the heat exchanger 4a in the buffer tank 4 ensures that the warmer water rises in the direction of arrow 33 to the ceiling of the buffer tank 4, while the colder water falls down the side walls of the buffer tank 4 in the direction of arrow 34 towards the floor.

A sensor F 5a is arranged in the ceiling area of the buffer tank 4 and another sensor F5b is arranged in the floor area.

A sensor F4 is arranged on the output side of the absorber 7.

A sensor F6 is arranged in the heat generator 2.

In the return line of the buffer tank 8, namely in the area of the line 12 and

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the line 17, a sensor Fl is arranged.

A sensor F2 is arranged in the flow of the heating system, namely in the area of line 31.

A sensor F3 is located in the lower part of the domestic hot water tank.

A sensor F7 is arranged in front of the return line 19 of the heat generator 2 and behind the lines 12,17 of the buffer tank 2 or the domestic hot water tank 3.

A minimum thermostat Dl is arranged in the corner area of buffer tank 4.

The system is now operated as follows:

The control device 5 fulfils the following functions:

Outdoor temperature dependent release of the heat generator heat pump

Bivalence point for release of 2nd heat generator with restriction of the minimum thermostat Tl, i.e. the oil burner is already released by the outside temperature, but is only switched on when the cold buffer tank 4 is empty.

Separate heating curve adjustable for the mixer Sl.

The heating circulation pump P2 is controlled according to demand.

The domestic water priority circuit causes the heat pump or the boiler to

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the upper temperature level is reached and the mixer Sl closes and the pump P2 switches off. A run-on time of 3 minutes ensures that the heat in the heat pump or boiler is still transported away after the required temperature has been reached at the sensor F3.

Additional functions of the control in the control cabinet in connection with the control 5.

The heat pump or burner is only released when the mixer motor Sl is fully open. This is achieved by an adjustable signal contact and a time delay.

The heat pump or burner will only switch off again when the required value is reached at the Fl sensor in the return. This means that the heating water buffer is completely flushed and charged.

The residual heat now present in the boiler is gradually fed to the heating water buffer using a differential temperature control system. For this purpose, sensor F6 is installed in the boiler and sensor F7 is installed in the return line from the buffer.

In order to bring the boiler up to temperature relatively quickly, the pump Pl is switched on with a delay after the burner starts.

The valve S3 is open to the heating water buffer when there is no current and when the hot water is to be heated, the valve switches to the heat exchanger in the hot water tank.

Charging pump Pl buffer tank 8:

The pump Pl must run when the oil boiler or heat pump is in operation with the following additional functions during heating operation (and hot water preparation). Start-up delay: (heating boiler operation only)

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In order to bring the boiler up to temperature relatively quickly, the pump is switched on with a delay via a time relay (adjustable 5 - 10 min.)

(Same function for hot water heating)

If the required temperature is reached at sensor Fl (sensor 3 for hot water preparation), the burner or the heat pump and the charging pump switch off. (For hot water preparation, valve S3 and the charging pump are supplied with power for another 3 minutes, i.e. part of the boiler heat is still discharged into the storage tank.)

In order to make effective use of the residual heat in the boiler, this heat is gradually fed into the heating buffer via a simple Λ t control.

The charging pump Pl is put into operation using two temperature sensors (F6 boiler and F7 return from buffer and heat exchanger) and a set Δt of approx. 8 K.

If the boiler has been started up to prepare hot water, the heat in the boiler is also fed to the heating buffer via this circuit.

Burner or heat pump activation or release during heating operation 1.) Via the boiler sensor Fl (with the restriction see 2)

2.) The additional signal contact in the mixer motor Sl releases the boiler or heat pump again after a time delay. At approx. 80 - 90% of the mixer opening, this contact activates a time relay, which then starts the burner or heat pump after 40 minutes.

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The following advantages are achieved by this circuit:

a. The storage volume is fully utilized.

b. This results in very long burner running times or downtimes without the boiler cooling down, since the heat is fed into the heating system.

c. The cycling of the oil burner with the respective pollutant emissions during start-up is greatly reduced.

In the following, the functions of the sorter circuit in conjunction with the heat pump 1 are described in more detail:

Pressureless cold buffer tank 4 with specially arranged heat exchanger made of copper finned tubes, capacity approx. 1,200 L. The latent storage tank is filled with normal water with the addition of a corrosion protection agent. A brine mixture with approx. 30% Antifrogen N content flows through the heat exchanger.

The sensor arrangement as well as the electronic control and the special integration of the heat exchanger 4a ensure optimal operation during charging and also during removal.

Charging process:

The differential temperature control device 6 and the two sensors F4 and F5b are used to determine whether the temperature level at F4 is higher than that at F5b. If this is the case, the brine pump P4 starts operating and the distribution valve S4 opens the path A-B. The buffer storage tank is now charged as long as the temperature at F4 is higher than that at F5b.

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The arrangement of the heat exchanger ensures that the upper warmer layer in the storage tank is partially transported downwards. This means that the buffer is completely heated and the greatest possible amount of energy is stored. There is a maximum limit on the storage tank temperature (protects the heat pump from overheating). At an adjustable difference of approx. 3 K, the brine pump P4 switches off again.

Unloading process:

When the heat pump is requested, the control device 6 first uses sensors F4 and F5a to check where the higher temperature level is. If this is the case at F5a, the distribution valve S4 opens the path B-AB and the pump P3 runs. The heat is now extracted from the buffer at the top via the heat exchanger 4a until the temperature at F5a is the same as F4 and then the heat is fed back to the heat pump via the absorber.

The buffer tank is equipped with a heat exchanger 4a, as well as a water level indicator, temperature sensors and a minimum thermostat Tl. As a base, form 1 insulating elements are used as well as a condensate collecting tray.

The /V t is constantly recorded (when the heat pump is running and when it is not running) with the control device 6.

For heat pump operation, the higher temperature level is always used, i.e. either absorber 7 or cold buffer tank 4. If heat pump 1 is requested by sensor Fl, the cold buffer tank side switches to the upper sensor F5a!

If HP 1 is switched off, the £Lt between F4 and F5b is compared and pump P4 is put into operation. (If F4^>like F5b).

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Three-way valve S4 Operating mode 1 Charging K-buffer

= Standstill of the heat pump At between F4 and F5b is compared and P4 is put into operation when heat is available.

Temperature at sensor F4 ^> as at F5b Mixer has opened path A - B (line 25,28) Pump P4 in operation In this circuit, the absorber heat is fed to the cold buffer tank. In addition, the warmer layer in the upper part of the cold buffer tank 4 is heated to 0.15 °C using the special arrangement of the heat exchanger 4a, thereby achieving optimum charging of the cold buffer tank.

Operating mode 2 HP operation with absorber

During WP operation, the Δt is compared between F4 and F5a.

Temperature at F4 ^" as F5a = absorber operation Pump P3 in operation Pump P4 in operation Mixer has opened path A-AB (line 25,26)

Operating mode 3 HP operation with cold buffer storage

Temperature at F5a > like F4 = cold buffer operation Mixer has opened path B-AB (line 28,26)

Brine pump P3

Pump starts operating with the heat pump

T. '

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(Operating time identical to WP)
Brine pump P4

Pump starts operation via Δt control device (whenever the sensor F4 has a higher temperature level than the sensor F5a in heat pump operation or in the rest position like 5b).

Thermostat Tl switches off the heat pump and enables the oil burner. Depending on the heat requirement of the house, the setting is approx. 0° or higher. The heat pump is now blocked for an adjustable time (U _n- , 1 «&Oacgr; JSIxL- -5+DSLiL) ! Reasons: Prevent the heat pump from cycling and achieve a reasonable running time and temperatures for the boiler and chimney.

If heat is requested again after this time and the heat pump is enabled at the set bivalence point on the TEM control, then it only goes into operation via the absorber if the temperature at F4 is temporarily higher than at F5a.

With the system described, burner running times of 1 3/4 hours could be achieved, whereby a 3-family house with a burner output of 21 kW had to be supplied with heat and domestic water at an outside temperature of 0 ⁰ C to +5 ⁰ C.

The buffer storage 8 was discharged once over a period of 1 1/2 hours, only then did the burner switch on again for a period of approx. 1 hour.

This was based on a boiler capacity of 30 to 40 litres compared to a buffer tank capacity of 120 litres.

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This ensures optimal operating conditions because the boiler is always operated at 30 to 60 ^° C, i.e. in the gentle operating range, and the downtime and radiation losses are minimal due to the small boiler capacity.

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DRAWING LEGEND

1 Heat pump Sl Three-way valve Pl pump CVJ Heat generator S2 Three-way valve1 P2 pump 3 Domestic water storage S3 Three-way valve P3 pump 4 Buffer storage S4 Three-way valve1 P4 pump 4a Heat exchanger 5 Rule device 6 Rule device Fl sensor Tl Minim 7 absorber F2 sensor 8th Buffer storage F3 sensor 9 Sctnk'cjTre F4 Feeder 10 Dip tube F5a sensor F5b sensor 11 Line F6 sensor 12 Line F7 sensor 13 Line 14 Line 27 Line 15 Heat exchanger 28 Line 16 Line 29 Line 17 Line 30 Bypass line 18 Flow (boiler 2) 31 Line 19 Return (boiler 2) 32 Line 20 Flow (heat pump) 33 Arrow direction 21 Return (heat pump) 34 Arrow direction 22 Line 23 Line 24 Line 25 Line 26 Line

Claims (12)

D-8990 Lindau (Bodensee) Rennerle 10 ■ PO Box 3160 Your reference Your message from Date , &lgr;1(. l I Yourref Yourletterof Date '· UKtODer I Reference: Re Applicant: Mr. Josef Moosmann, Affentäle 2a, 7741 Tennenbronn Protection claims 1. Heating arrangement with at least one heat generator, which is connected to a buffer storage tank in order to reduce the burner cycles, the buffer storage tank being connected on the one hand between the flow and return of the heat generator and on the other hand between the flow and return of the heating circuit in the manner of a heating water buffer, characterized in that a heat exchanger (15) is connected in parallel to the buffer storage tank (8) in the additional service water storage tank (3), whereby a uniform combination storage tank is created. Telephone: Telex: Facsimile / fax 1 Lindau (0 83 82) 5 43 74 (patent-d) -49-8382 -7802 7 80 25 Telegram address: patri-lindau ^ ^ around L ¹ : &rgr;&uacgr; 1% Bank accounts: Postal checking account Bayer. Vereinsbank Lindau (B) No. 1257 110 (bank code 735 200 741 Munich 414 843-808 Hypo-Bank Lindau (B) No. 66 70-326 843 (bank code 733 204 42) (bank code 700 100 80) Volksbank Lindau (B) No. 51 222 000 (bank code 735 901 20) -2- 2. Heating arrangement according to claim 1, characterized characterized in that, in order to charge the domestic water storage tank (3), a three-way valve (S3) is arranged in the flow line (line 11) of the buffer storage tank (8) and the heat generator (2), one line (16) of which forms the flow line of the heat exchanger (15) of the domestic water storage tank (3). 3. Heating arrangement according to claim 1, characterized characterized in that a heat pump arrangement consisting of absorber (7), buffer storage (4) and heat pump (1) is connected in parallel to the heat generator (2). 4. Heating arrangement according to claim 1, characterized in that the combination storage tank, consisting of buffer storage (8) and domestic water storage tank (3), is arranged parallel to the heat generator (2) on the one hand, and that the heat pump arrangement, consisting of absorber (7), buffer storage tank (4) and heat pump (1) on the other hand, is connected in parallel to the heat generator (2). 5. Heating arrangement according to claim 4, characterized in that a domestic water priority circuit causes the heat pump (1) or the heat generator (2) to be run to the maximum achievable temperature level, and that the three-way valve (S1) arranged in the heating circuit (31, 32) closes and switches off the pump (P2) arranged there, whereby the heat is transported away from the heat generator (2) or the heat pump (1) with a run-on period of, for example, 3 minutes after the domestic water temperature determined by a sensor (F3) has been reached. 6. Heating arrangement according to claims 1 to 5, characterized in that the heat pump (1) or the -3- Heat generator (2) may only be started when the three-way valve (Sl) in the heating circuit (31,32) is fully open. 7. Heating arrangement according to claim 4, characterized in that the heat pump (1) or the heat generator (2) only switch off when a predetermined value is reached by a sensor (Fl) in the return line (19, 21) and that the then residual heat in the heat generator (2) is gradually fed to the buffer storage (8) by a differential temperature control system (5). 8. Heating arrangement according to claim 7, characterized characterized in that the differential temperature control (5) consists of a sensor (F6) arranged in the heat generator (2) and of a sensor (F7) arranged in the return line (line 12) from the buffer storage tank (8). 9. Heating arrangement according to claims 1 and 2, characterized in that the pump (P1) arranged in the heating circuit (22, 23) is switched on with a delay in order to accelerate the heating of the starting heat generator (2). 10. Heating arrangement according to claims 1 to 4, characterized in that a three-way valve (S2) is provided for switching the flow (line 20) of the heat pump (1) and the flow (line 18) of the heat generator (2) to the buffer storage tank (8). 11. Heating arrangement according to claims 1 to 4, characterized in that a differential temperature control device (6) with two sensors (F4, F5a) on the input side is provided for operating the heat pump (1), one sensor (F4) in the return line (line 25) of the absorber (7) and the other sensor (F5a) in the upper area -4- a further buffer storage tank (4) is arranged, that at a higher temperature level on the return line (line 25) of the absorber (7) compared to the bottom-side temperature of the buffer storage tank (4) the pump (P4) for the brine circuit of the absorber (7) is switched on and that furthermore in the branching point between the return line (line 25) of the absorber (7) the flow line (line 27) of the heat pump (1) and the return line (line 28) of the buffer storage tank (4) a three-way valve (S4) is arranged, which opens the return line (line 27) to the heat pump (1) for this operating case. 12. Heating arrangement according to claim 11, characterized in that, in order to discharge the further buffer storage tank (4), it is first provided that the temperature level in the upper "area of the buffer storage tank 14") is set higher than that on the return side of the absorber (7), and that the three-way valve (S4) to the flow line (line 27) of the heat pump then opens until the temperature in the upper area of the buffer storage tank (4) is approximately equal to the temperature in the return line (line 25) of the absorber (7).