DE102018124429A1 - Water heating system and method for the efficient and hygienic operation of a domestic hot water storage charging system of a water heating system - Google Patents

Abstract

The object of the invention is to provide a method for the efficient and hygienic operation of a domestic hot water storage charging system.
Hot water preparation system (1) with a primary Heizwasserkreislauf (2) and a secondary drinking water circuit (3) which is coupled via a heat exchanger system (4) with the primary Heizwasserkreislauf (2) and a domestic hot water circulation circuit (5), one with the domestic hot water circulation circuit (5) coupled domestic hot water tank (6) and with the heat exchanger system (4) connected storage charging system (7), wherein the heat transfer system (4) a first heat exchanger (8) as a reheater (8) for the domestic hot water circulation circuit (5) and / or the storage charging system (7) and a second heat exchanger (9) as a preheater (9) at least for the storage loading system (7), wherein in a common line section (10) of the domestic hot water circulation circuit (5) and the storage loading system (7 ) A pump (11) is arranged and that the domestic hot water circulation circuit (5) and / or the Speicherladesyste m (7) comprises a volume flow sensor (12), and that in the flow (13) of the primary heating water circuit (2) of the first heat exchanger (8) and in the secondary flow (14) of the first heat exchanger (8) and in the circulation return (16) of the domestic hot water circulation circuit (5) and in the secondary return (21) of the second heat exchanger (9) each have a temperature sensor (B1, B2, B3, B6) is arranged, and that in the storage charging system (7) a valve ( 18) for setting or regulating the accumulator charge volume flow, wherein at least one or more of the volumetric flow sensor (12), the temperature sensors (B1, B2, B3, B6) and the armature (18) for controlling the accumulator charge volumetric flow are connected to a control unit (19) or control unit (19) are connected.

Description

Two-stage accumulator charging system, where the first stage serves as a preheating stage and the second stage as a reheating stage. The DHW circulation is heated only via the reheating stage, the storage charge via preheating and Nachwärmstufe. The integrated energy manager in the DDC controls the heat output of the domestic hot water circulation. The now still usable amount of heat of the circulation return is calculated by the DDC and the storage charge made available. The anticipatory energy content of the DHW tank allows the DDC to recognize how much heat can be recovered from the circulation return.

Is known from the DE 10 2010 044 535 B4 a scheme and corresponding arrangement in which the control of the heating water return temperature in the primary return of the second heat exchanger of a heat exchanger system by controlling the mass flow of drinking water through the second heat exchanger in the secondary drinking water circuit. Here, therefore, a target temperature is specified, which is achieved by controlling the secondary mass flow or should be controlled.

The object of the invention is to provide a method for the efficient and hygienic operation of a domestic hot water storage charging system.

With the invention is achieved in the specified application that a redistribution of heat energy from the domestic hot water circulation circuit and in the storage loading system is created, whereby the efficient operation and by the corresponding heating so the charge of the storage a hygienic operation is achieved.

In the preferably used two-stage accumulator charging system, a first stage is present as a preheating stage and a second stage as a reheating stage. The warming of the drinking water circulation takes place only via the postheating stage, while the storage charge takes place via the preheating stage and reheating stage. In the DDC control, the heat output of the domestic hot water circulation is recorded and the still usable heat quantity of the circulation return is calculated and made available to the storage tank. The predictive energy content of the domestic hot water tank enables the DDC to recognize how much heat output can be obtained from circulation return.

For this purpose, the hot water preparation system has a primary heating water circuit and a secondary drinking water circuit, which is coupled to the primary heating water circuit via a heat exchanger system. In the drinking water circuit, a domestic hot water circulation circuit and a coupled with the DHW circulation circulation hot water tank and a connected to the heat exchanger system storage charging system are available. The heat exchanger system comprises a first heat exchanger as a reheater for the domestic hot water circulation circuit and / or the storage charging system and also a second heat exchanger as a preheater, at least for the storage charging system or if the system is designed accordingly, for preheating drinking cold water if this is not on the domestic hot water tank but on the Two-stage water heating should enter the circulation. In a common line section of the domestic hot water circulation circuit and the storage charging system, a pump is arranged. In the DHW circulation circuit and / or in the storage charging system, a volume flow sensor is present. In the flow of the primary Heizwasserkreislaufes the first heat exchanger and the secondary flow of the first heat exchanger and the circulation return of the domestic hot water circulation circuit and the secondary return of the second heat exchanger, a temperature sensor is arranged in each case. In the storage loading system, a valve for adjusting or regulating the storage loading volume flow is also available. At least one or more volumetric flow sensors, the temperature sensors and the valve for controlling the accumulator charge volume flow are connected to a control unit or control unit. This arrangement allows a needs-based implementation of the method for efficient and hygienic operation of a storage charging system whereby available energy potentials and existing energy needs can be detected and taken into account.

Valves are understood to mean, for example, valves in the form of valves to be adjusted by a motor or otherwise adjustable valves which are suitable for adjusting the volume flow via a cross-sectional change.

In a further development, the domestic hot water storage is arranged inside or outside the domestic hot water circulation circuit, whereby the charge of the domestic hot water tank is made possible by the circulation volume flow as required and need during the circulation to a small extent, as this is optionally guided by the domestic hot water tank. In the case of a arranged outside the drinking water circulation circuit drinking water storage a change in direction of the respective volume flow by adjusting the flow conditions would be required.
Advantageously, the pump is arranged in the common line section of the secondary return or in the common line section of the secondary flow of the first heat exchanger, whereby only a single pump needs to be used. In particular, the pump is arranged in the common line section of the secondary return to the first heat exchanger, this is only exposed to temperatures of about 55 degrees Celsius whereby the calcification of the pump is reduced.

By the pump is connected to the control unit or control unit, it can be dynamically adapted to the conditions.

By at least one temperature sensor is provided at the domestic hot water tank, wherein the at least one temperature sensor is connected to the control unit or control unit, the level of the domestic hot water tank can be determined. The more temperature sensors present and arranged, the more precisely can the level be controlled and the charge influenced.

By arranging the volume flow sensor of the domestic hot water circulation circuit in the circulation return and / or the volume flow sensor of the storage charging system in the secondary return of the second heat exchanger, the respective volume flows can be determined without interference, whereby the method is improved. In addition, the volume flow sensors are subject only to a limited thermal load, which can minimize their calcification.

By arranging the accumulator flow volume flow control valve on the secondary flow or secondary return of the second heat exchanger, the accumulator volume flow can be adjusted accurately and uninfluenced by the specifications.

By the valve for controlling the circulation volume flow in the circulation return of the DHW circulation circuit is present and the valve for controlling the circulation volume flow to the control unit or control unit, the volume flow through the circulation can be adjusted so that even with low pressure loss in the circulation charging the heat storage is preferred and favored. With this valve for controlling the circulation volume flow, it can be achieved that the volume flow for the storage charge can be adapted directly by adjusting the circulation volume flow. It is possible that the degree of opening of the valve in the storage charging circuit by means of a control on a defined and compared to the domestic hot water circulation circuit lower storage loading volume flow is adjusted and not necessarily readjusted. However, an active control of the valve to control the storage loading volume flow is not excluded and also possible or is provided. For example, the degree of opening of the valves for controlling the circulation volume flow is fully open, whereby the secondary flow of the first heat exchanger or the Nachwärmers preferably the domestic hot water circulation circuit operated and not or only to a small extent as Speicherladevolumenstrom the DHW tank loads because the valve in the storage charging circuit with the lower degree of opening generates a higher flow resistance and thus the secondary flow tends to flow into the domestic hot water circulation circuit.

According to a further development, a temperature sensor is arranged in the primary-side connection of the first heat exchanger to the second heat exchanger or in the flow of the primary heating water circuit of the second heat exchanger and / or in the secondary flow of the second heat exchanger, wherein the one or more temperature sensors connected to the control unit or control unit are. This allows more individual and dynamic modes of operation to be achieved.

The method for efficient and hygienic operation of a domestic hot water storage charging system of a hot water system with a primary heating water circuit and a secondary drinking water circuit, which is coupled via a heat exchanger system with the primary Heizwasserkreislauf, and a domestic hot water circulation circuit, which is coupled to a domestic hot water tank, and one with the Includes heat transfer system connected storage charging system and that the heat exchanger system comprises a first heat exchanger as a reheater for the domestic hot water circulation circuit and / or the storage charging system and a second heat exchanger as a preheater for at least the storage charging system, provides various steps.

erfolgt die Leistungsermittlung der Trinkwarmwasserzirkulation.For determining the performance of the drinking water circulation in step 1 the volume flow of the domestic hot water circulation circuit, the temperatures are detected by temperature sensors in the secondary flow of the first heat exchanger and in the circulation return of the domestic hot water circulation circuit. According to the formula $$\text{P}{\text{,}}_{\text{circ}}=\left(\text{B2-B3}\right)*\text{VS1 * spec}\text{.Wärmekapazität}$$

the performance determination of the drinking water circulation takes place.

oder $$\text{VS}{\text{.}}_{\text{Hzw}}=\text{P}{\text{.}}_{\text{zirk}}\text{/}\left(\text{B1}-\text{B4}+1\text{K}\right)\text{/spez}\text{.Wärmekapazität}$$

berechnet.The primary volume flow of the heating water in step 2 is determined by the power determination of the hot water circulation, the temperature of the heating water to be measured in the flow of the first heat exchanger and the measured temperature of the circulation return of the domestic hot water circulation circuit according to the formula $$\text{VS}{\text{,}}_{\text{HZW}}=\text{P}{\text{,}}_{\text{circ}}\text{/}\left(\text{B1}-\text{B3}+1\text{K}\right)\text{/ spec}\text{.Wärmekapazität}$$

or $$\text{VS}{\text{,}}_{\text{HZW}}=\text{P}{\text{,}}_{\text{circ}}\text{/}\left(\text{B1}-\text{B4}+1\text{K}\right)\text{/ spec}\text{.Wärmekapazität}$$

calculated.

berechnen, wobei hierfür statt der gemessenen Temperatur des Zirkulationsrücklaufes des Trinkwarmwasser-Zirkulationskreislaufes die Temperatur im Vorlauf des primären Heizwasserkreislaufes des zweiten Wärmeübertragers gemessen und in die Berechnung einbezogen wird.Alternatively, the primary volume flow can also be according to the formula $$\text{VS}{\text{,}}_{\text{HZW}}=\text{P}{\text{,}}_{\text{circ}}\text{/}\left(\text{B1}-\text{B5}\right)\text{/ spec}\text{.Wärmekapazität}$$

calculate, for which instead of the measured temperature of the circulation return of the domestic hot water circulation circuit, the temperature in the flow of the primary heating water circuit of the second heat exchanger measured and included in the calculation.

oder $$\text{VS}{\text{.}}_{\text{Hzw}}=\text{P}{\text{.}}_{\text{zirk}}\text{/}\left(\text{B1}-\text{B4}+1\text{K}\right)\text{/spez}\text{.Wärmekapazität}$$

eine einfachen Berechnungsmethode für einen statischen Betrieb darstellt, ist mit der Formel $$\text{VS}{\text{.}}_{\text{Hzw}}=\text{P}{\text{.}}_{\text{zirk}}\text{/}\left(\text{B1}-\text{B5}\right)\text{/spez}\text{.Wärmekapazität}$$

eine dynamische Ermittlung und damit Anpassung möglich.While the formula $$\text{VS}{\text{,}}_{\text{HZW}}=\text{P}{\text{,}}_{\text{circ}}\text{/}\left(\text{B1}-\text{B3}+1\text{K}\right)\text{/ spec}\text{.Wärmekapazität}$$

or $$\text{VS}{\text{,}}_{\text{HZW}}=\text{P}{\text{,}}_{\text{circ}}\text{/}\left(\text{B1}-\text{B4}+1\text{K}\right)\text{/ spec}\text{.Wärmekapazität}$$

is a simple calculation method for a static operation is with the formula $$\text{VS}{\text{,}}_{\text{HZW}}=\text{P}{\text{,}}_{\text{circ}}\text{/}\left(\text{B1}-\text{B5}\right)\text{/ spec}\text{.Wärmekapazität}$$

a dynamic determination and thus adaptation possible.

In one step 3 the determination of the desired spread of the preheater takes place. The basic requirement for this is that the temperature of the heating water in the flow of the primary Heizwasserkreislaufes and the temperature of the circulation return of the domestic hot water circulation circuit or the temperature in the primary side connection of the first heat exchanger to the second heat exchanger or the temperature of the flow of primary Heizwasserkreislaufes the second heat exchanger basically above Temperature must be in the secondary return of the second heat exchanger, so that heat energy is added via the preheater to the storage loading system.

The target temperature spread is defined via a curve to be set and subsequently by the control unit or control unit as a function of the temperature B6 calculated.

The determination of the nominal power of the preheater in step 4 takes place via a fixed specification of the temperature spread between the inlet and outlet temperature of the preheater on Heizwasserseite, ie the primary side depending on the inlet temperature of the preheater on the storage loading side, ie the secondary side. For this purpose, the temperature in the secondary return of the second heat exchanger is measured.

• dT.Sekundär.SOLL = (B5-1K)-B6 oder B3-B6

The determination of the nominal volume flow of the preheater on the secondary side according to step 5 is determined by the nominal output of the preheater as a function of a calculated temperature spread between the inlet and outlet temperature on the secondary side:

• dT.secondary.SOLL = (B5-1K) -B6 or B3-B6

• VS.Sekundär.SOLL = P.SOLL/dT.Sekundär.SOLL/c

As a result, the accumulator charge volume flow is regulated or adjusted.

• VS.Secondary.SOLL = P.SOLL / dT.Secondary.SOLL / c

By means of the valve for controlling the accumulator charge volume flow of the target volume flow of the preheater is regulated or adjusted on the secondary side.

Various embodiments of the invention are illustrated in the drawings and will be described in more detail below.

• 1 einen möglichen Schaltungsaufbau mit optionalen Bauelementen,
• 2 einen alternativen Schaltungsaufbau
• 3 einen alternativen Schaltungsaufbau
• 4 den Schaltungsaufbau der 1 mit hervorgehobenen Speicherladesystem und
• 5 den Schaltungsaufbau der 1 mit hervorgehobenen Trinkwarmwasser-Zirkulationskreislauf.

Show it

• 1 a possible circuit structure with optional components,
• 2 an alternative circuit construction
• 3 an alternative circuit construction
• 4 the circuit structure of 1 with highlighted storage loading system and
• 5 the circuit structure of 1 with highlighted DHW circulation circuit.

The 1 shows an exemplary circuit structure of a hot water preparation system according to the invention 1 that is a primary heating water 2 and a secondary drinking water cycle 3 comprising, which via a heat exchanger system 4 with the primary heating water circuit 2 is coupled and a drinking water circulation circuit 5 , as well as one with the domestic hot water circulation circuit 5 coupled domestic hot water tank 6 and one with the heat transfer system 6 connected storage loading system 7 includes. The heat exchanger system 4 includes a first heat exchanger 8th as a reheater 8th for the domestic hot water circulation circuit 5 and / or the storage loading system 7 and further a second heat exchanger 9 as a preheater 9 for at least the storage loading system 7 , In a common line section 10 of the domestic hot water circulation circuit 5 and the storage loading system 7 is a pump 11 arranged.
The domestic hot water circulation circuit 5 and the storage loading system 7 include a volumetric flow sensor 12 ,

Furthermore, there are different temperature sensors B1 . B1 . B2 . B3 . B6 intended.
In the lead 13 of the primary heating water circuit 2 of the first heat exchanger 8th is the temperature sensor B1 intended.
In the secondary forerun 14 of the first heat exchanger 8th is the temperature sensor B2 and in the circulation return 16 of the domestic hot water circulation circuit 5 the temperature sensor B3 intended.
In the secondary return 21 of the second heat exchanger 9 is the temperature sensor B6 arranged.

In addition, additional temperature sensors can be B4 . B5 provide, alternatively or additionally provide readings that can be integrated into the control or control with minimal effort. So is in the primary-side connection of the first heat exchanger 8th to the second heat exchanger 9 or in the lead 15 of the primary heating water circuit 2 of the second heat exchanger 9 a temperature sensor B5 available. In the secondary forerun 20 of the second heat exchanger 9 is a temperature sensor B4 arranged. The temperature sensors B4 . B5 are with the control unit 19 or control unit 19 connected.

In the storage loading system 7 is a fitting 18 for adjusting or regulating the accumulator charge volume flow.

The volume flow sensor 12 , the temperature sensors B1 . B2 . B3 . B6 and the fitting 18 for controlling the accumulator charge volume flow are with a control unit 19 or control unit 19 connected.

In the concrete example, the domestic hot water tank 6 within domestic hot water circulation circuit 5 arranged.

The pump 11 is in the common line section 10 of the secondary flow 14 or circulation lead 14 of the first heat exchanger 8th arranged. The pump 11 but can also be in the common line section 10 of the secondary reflux 17 of the first heat exchanger 8th Arrange.

The pump 11 is with the control unit 19 or control unit 19 connected.

Furthermore, the hot water storage tank 6 in the specific example four temperature sensor B7 is provided, wherein the temperature sensors B7 with the control unit 19 or control unit 19 are connected.

The volume flow sensor 12 of the domestic hot water circulation circuit 5 is in the concrete example in the circulation return 16 and the volumetric flow sensor 12 of the storage loading system 7 is in the concrete example in the secondary return 21 of the second heat exchanger 9 arranged.

The fitting 18 for controlling the accumulator charge volume flow is secondary return in the concrete example 21 of the second heat exchanger 9 arranged. However, it is also possible the fitting 18 at the secondary forerun 20 of the second heat exchanger 9 to arrange if necessary.

Furthermore, a fitting 22 for controlling the circulation volume flow in the circulation return 16 of the domestic hot water circulation circuit 5 available. The fitting 22 for controlling the circulation volume flow is connected to the control unit 19 or control unit 19 connected.

In deviation to 1 is in 2 the fitting 18 not with the scheme 19 connected. The fitting 18 is in this case a manually set valve, which can also be driven by a motor. Because in this case the fitting 18 has a static value, the regulation and distribution of the volume flow takes place by means of the setting of the valve 22 as adjustable valve in the circulation return 16 of the domestic hot water circulation circuit 5 which with the scheme 19 connected is.

In deviation to 1 and 2 is in 3 the pump 11 in the secondary return 17 of the first heat exchanger 8th shown. The secondary return 17 of the first heat exchanger 8th is also the common line section 10 ,

The 4 equals to 1 , wherein the storage loading system 7 is particularly highlighted. The storage loading system 7 includes the drinking water storage 6 , the at the bottom or cold area of the drinking water storage 6 connected secondary return 21 of the second heat exchanger 9 or preheater 9 , the second heat exchanger 9 or preheater 9 , the secondary flow 20 of the second heat exchanger 9 or preheater 9 in the secondary return 17 of the second heat exchanger 8th or reheater 8th passes, the second heat exchanger 8th or reheater 8th , the secondary flow 14 of the reheater 8th as well as the circulation lead 14 corresponds and thus also the common line section 10 is, and again the drinking water storage 6 , In the secondary return 21 of the second heat exchanger 9 or preheater 9 are the feed for drinking cold water 23 , a volumetric flow sensor 12 , as well as a fitting 18 and a temperature sensor B6 arranged.

The 5 equals to 1 , wherein the domestic hot water circulation circuit 5 is particularly highlighted. The drinking water circulation circuit 5 includes the second heat exchanger 8th or reheater 8th , the secondary flow 14 of the reheater 8th as well as the circulation lead 14 corresponds and thus also the common line section 10 is the drinking water storage 6 or a branch or a branch line to the drinking water reservoir 6 (not shown), the continued circulation lead 14 , which at the latest after the last tapping point 24 in the circulation return 16 passes, in turn, in the secondary return 17 of the reheater 8th or first heat exchanger 8th goes over and back into the reheater 8th or first heat exchanger 8th arrives. In the circulation return 16 are a flow meters 12 , and a fitting 22 and a temperature sensor B3 even before the transition to secondary reflux 17 of the reheater 8th or first heat exchanger 8th arranged.

In the 1 to 5 in each case a two-stage storage loading system is shown, wherein the first stage with the preheater 9 or second heat exchanger 9 as preheating stage and the second stage with the reheater 8th or first heat exchanger 8th serves as a reheating stage. The drinking water circulation is heated only via the reheating stage, while the storage charge is carried out via the preheating stage and reheating stage.

The integrated energy manager in the DDC Control detects the heat output of the domestic hot water circulation. The now still usable amount of heat of the circulation return is of the DDC calculated and provided the storage load.

When used, so when tapping at the taps 24 , drinking cold water flows 23 over the line section as a connecting line between preheater 9 and domestic hot water storage 6 or between feed drinking cold water 23 and domestic hot water storage 6 , also called secondary rewind 21 in the preheater 9 gets into the domestic hot water tank 6 ,

The inventive method relates to an efficient and hygienic operation of a domestic hot water storage tank system of a water heating system 1 , At this is a primary Heizwasserkreislauf 2 and a secondary drinking water circuit 3 via a heat transfer system 4 coupled together. The drinking water cycle 3 includes a domestic hot water circulation circuit 5 Having a drinking water storage tank 6 coupled, and one with the heat transfer system 4 connected storage loading system 7 , The heat exchanger system 4 includes a first heat exchanger 8th as a reheater 8th for the domestic hot water circulation circuit 5 and / or the storage loading system 7 and a second heat exchanger 9 as a preheater 9 especially for the storage loading system 7 ,

In one step 1 of the method, a performance determination of the drinking water circulation according to the above formula is carried out: $$\text{P}\text{.zirk}=\left(\text{B2-B3}\right)*\text{VS1 * spec}\text{.Wärmekapazität}\left(\text{c}\right)$$

• B2=60 Grad Celsius und
• B3=55 Grad Celsius

By way of example, the following values of the temperature sensors were measured:

• B2 = 60 degrees Celsius and
• B3 = 55 degrees Celsius

The specific heat capacity c = 1,16.
The volume flow sensor 22 returns the value 1.000l / h.

This results in a performance of the drinking water circulation: $$\text{P}\text{.zirk}=\text{5K * 1}\text{.000l / h * 1}\text{16}=\text{5}\text{, 8kw}$$

In step 2 of the method, the determination of the primary heating water flow rate according to the above formula $$\text{VS}\text{.Hzw}=\text{P}\text{.zirk /}\left(\text{B1}-\text{B3}+1\text{K}\right)\text{/ spec}\text{.Wärmekapazität}$$

oder alternativ $$\text{VS}\text{.Hzw}=\text{P}\text{.zirk/}\left(\text{B1}-\text{B5}\right)\text{/spez}\text{.Wärmekapazität}\left(\text{c}\right)$$

Or alternatively $$\text{VS}\text{.Hzw}=\text{P}\text{.zirk /}\left(\text{B1}-\text{B4}+1\text{K}\right)\text{/ spec}\text{.Wärmekapazität}$$

or alternatively $$\text{VS}\text{.Hzw}=\text{P}\text{.zirk /}\left(\text{B1}-\text{B5}\right)\text{/ spec}\text{.Wärmekapazität}\left(\text{c}\right)$$

With the example calculated value from step 1 the performance of domestic hot water circulation P. district = 5,8kW and the measured values of the temperature sensors
B1 = 80 degrees Celsius
B5 = 56 degrees Celsius = B3 + 1K
and the specific heat capacity c = 1.16 results for the primary heating water volume flow: $$\text{VS}\text{.Hzw}=5.8\text{kw / 24k / 1}\text{16}=208\text{l / h}$$

In step 3 of the method, the determination of the target spread of the preheater takes place 9 ,

The basic requirement for this is that the temperatures at the temperature sensors B5 respectively. B3 basically over those at the temperature sensor B6 must lie so that heat energy to the preheater 9 of the storage loading system 7 is added.

The target temperature spread is defined by a curve to be set and then by the DDC as a function of the measured temperatures of the temperature sensor B6 calculated.

• B6=10 Grad Celsius
• dT.Primär.SOLL= 20K
• B6=15 Grad Celsius
• dT.Primär.SOLL= 15K

Die Kurve kann angepasst werden.For example, the following target spread was specified:

• B6 = 10 degrees Celsius
• dT.Primary.SOLL = 20K
• B6 = 15 degrees Celsius
• dT.Primary.SOLL = 15K

The curve can be adjusted.

In step 4 the determination of the desired power of the preheater 9 , The power is a fixed specification of the temperature spread between the inlet and outlet temperature of the preheater 9 on the primary side, ie on the heating water side, depending on the inlet temperature of the preheater 9 determined on the secondary side on the memory loading side.

By way of example, the heating water volume flow VS.Hzw = 2081 / h,
the target temperature spread dT.Primary.SOLL = 20K and
the specific heat capacity c = 1,16
the SOLL performance: $$\text{P}\text{.SHOULD}=\text{208l / h * 20K * 1}\text{16}=4.8\text{kw}$$

In step 3 of the method, the determination of the nominal volume flow of the preheater takes place 9 secondary side.

The determination of the nominal volume flow of the preheater 9 on the secondary side is done by the target performance of the preheater 9 depending on a calculated temperature spread between inlet and outlet temperature on the secondary side.

By way of example, it follows from the step 4 determined SOLL power P.SOLL = 4,8kW, the measured values of the temperature sensors
B5 = 56 degrees Celsius and
B6 = 10 degrees Celsius,
and the specific heat capacity c = 1.16, first the temperature spread
dT.second.SOLL = (B5-1K) -B6 or B3-B6 = 46K

This results according to the formula:
VS.Secondary.SOLL = P.SOLL / dt.secondary.SOLL / c
the storage loading volume flow of
VS.secondary.SOLL = 4.8 / 46K / 1.16 = 90l / h

As a result of this example, the valve regulates 18 the nominal volume flow of the preheater 9 on the secondary side. The volume flow sensor 12 in the secondary return 21 of the preheater 9 detects the volume flow.

LIST OF REFERENCE NUMBERS

1 -

Water heating system

2 -

primary heating water circuit

3 -

Drinking water circulation

4 -

Heat exchanger

5 -

Domestic hot water circulation circuit

6 -

DHW

7 -

Store system

8th -

first heat exchanger, reheater

9 -

second heat exchanger, preheater

10 -

common line section

11 -

pump

12 -

Flow Sensor

13 -

leader

14 -

secondary flow, circulation forward

15 -

leader

16 -

Circulation return

17 -

secondary reflux

18 -

fitting

19 -

Control unit, control unit

20 -

secondary flow

21 -

secondary reflux

22 -

fitting

23 -

Drinking cold water

24 -

taps

B1 -

temperature sensor

B2 -

temperature sensor

B3 -

temperature sensor

B4 -

temperature sensor

B5 -

temperature sensor

B6 -

temperature sensor

B7 -

temperature sensor

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010044535 B4 [0002]

Claims (12)

Hot water preparation system (1) with a primary Heizwasserkreislauf (2) and a secondary drinking water circuit (3) which is coupled via a heat exchanger system (4) with the primary Heizwasserkreislauf (2) and a domestic hot water circulation circuit (5), one with the domestic hot water circulation circuit (5) coupled domestic hot water tank (6) and connected to the heat exchanger system (4) storage charging system (7), wherein the heat transfer system (4) a first heat exchanger (8) as a reheater (8) for the domestic hot water circulation circuit (5) and / or the storage charging system (7) and a second heat exchanger (9) as preheater (9) at least for the storage charging system (7), wherein in a common line section (10) of the domestic hot water circulation circuit (5) and the storage loading system (7) a pump (11) is arranged and that the domestic hot water circulation circuit (5) and / or the storage charging system (7) comprises a volumetric flow sensor (12) includes, and that in the flow (13) of the primary Heizwasserkreislaufes (2) of the first heat exchanger (8) and in the secondary flow (14) of the first heat exchanger (8) and in the circulation return (16) of the domestic hot water circulation circuit (5) and in the secondary return (21) of the second heat exchanger (9) in each case a temperature sensor (B1, B2, B3, B6) is arranged, and in that an accumulator (18) for adjusting or regulating the accumulator charge volume flow is present in the accumulator charging system (7), at least the one or more volumetric flow sensors (12), the temperature sensors (B1, B2, B3, B6) and the armature (18) for regulating the Storage tank volume flow with a control unit (19) or control unit (19) are connected. Hot water preparation plant after Claim 1 , characterized in that the domestic hot water storage tank (6) is arranged inside or outside of the domestic hot water circulation circuit (5). Water heating system according to one of Claims 1 and 2 , characterized in that the pump (11) in the common line section of the secondary return (17) or in the common line section (10) of the secondary flow (14) of the first heat exchanger (8) is arranged. Hot water preparation system according to one of the preceding claims, characterized in that the pump (11) with the control unit (19) or control unit (19) is connected. Hot water preparation system according to one of the preceding claims, characterized in that at least one temperature sensor (B7) is provided at the domestic hot water tank (6), wherein the at least one temperature sensor (B7) is connected to the control unit (19) or control unit (19). Hot water preparation system according to one of the preceding claims, characterized in that the volume flow sensor (12) of the domestic hot water circulation circuit (5) in the circulation return (16) and / or that the volume flow sensor (12) of the storage loading system (7) in the secondary return (21) of the second Heat exchanger (9) is arranged. Hot water preparation system according to one of the preceding claims, characterized in that the valve (18) for controlling the accumulator charge volume flow at the secondary flow (20) or secondary return (21) of the second heat exchanger (9) is arranged. Hot water preparation system according to one of the preceding claims, characterized in that a valve (22) for controlling the circulation volume flow in the circulation return (16) of the domestic hot water circulation circuit (5) is provided, wherein the valve (22) for controlling the circulation volume flow to the control unit (19 ) or control unit (19) is connected. Hot water preparation system according to one of the preceding claims, characterized in that in the primary-side connection of the first heat exchanger (8) to the second heat exchanger (9) or in the flow (15) of the primary Heizwasserkreislaufes (2) of the second heat exchanger (9), a temperature sensor (B5) and / or in the secondary flow (20) of the second heat exchanger (9), a temperature sensor (B4) is arranged, wherein the one or more temperature sensors (B4, B5) to the control unit (19) or control unit (19) are connected. Method for the efficient and hygienic operation of a domestic hot water storage charging system of a water heating system (1) with a primary heating water circuit (2) and a secondary drinking water circuit (3) which is coupled via a heat exchanger system (4) with the primary Heizwasserkreislauf (2), and a domestic hot water Circulation circuit (5), which is coupled to a domestic hot water storage tank (6), and a storage charging system (7) connected to the heat transfer system (4), and in that the heat transfer system (4) comprises a first heat exchanger (8) as reheater (8) for the domestic hot water - Circulation circuit (5) and / or the storage charging system (7) and a second heat exchanger (9) at least as a preheater (9) for the storage charging system (7), wherein in a step 1, the performance of the domestic hot water circulation takes place, in a step 2, the determination the primary volume flow of the heating water takes place, in a step 3, the determination of the target spread of the preheater (9), in a step 4, the determination of the target power of the preheater (9), in a step 5, the determination of the secondary target Volume flow of the preheater (9) and in a step 6, the target volume flow of the preheater (9) is regulated or adjusted on the secondary side. Method according to Claim 10 , characterized in that the determination of the primary volume flow of the heating water takes place statically or dynamically. Method according to one of Claims 10 and 11 , characterized in that the determination of the primary volume flow of the heating water by means of the power of the domestic hot water circulation, the measured temperature of the heating water in the flow (13) of the primary Heizwasserkreislaufes (2) and the measured temperature of the circulation return (16) of the domestic hot water circulation circuit (5 ) or the measured temperature in the primary-side connection of the first heat exchanger (8) to the second heat exchanger (9) or the measured temperature of the flow (15) of the primary Heizwasserkreislaufes (2) of the second heat exchanger (9).

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