EP3835667A1 - Method for controlling a heating system and control device for same - Google Patents

Abstract

A method for controlling a heating system (100) with a heat generator (101), with at least one heating circuit (111) for heating the building and with hot water preparation (121) for heating domestic water and a control device for this are described. A heat generator flow temperature ϑWEVL is selected to be greater than or equal to the heating circuit setpoint temperature ϑHZsoll and a mixer (112) is provided for setting a heating circuit flow temperature ϑHZVL. During hot water preparation, a regular heating circuit setpoint temperature ϑHZsoll in heating mode is reduced by a configurable value and after hot water preparation (121) it is reset to the regular heating circuit setpoint temperature ZHZsoll for heating operation.

Description

The invention relates to a method for controlling a heating system with preferably a condensing boiler as a heat generator, with at least one heating circuit for heating the building and with hot water preparation for heating domestic water to a target hot water temperature. The heated domestic water can be stored in a hot water storage tank, for example. A heat generator flow temperature is selected to be greater than or equal to the target heating circuit temperature, and a mixer is provided for setting a target heating circuit temperature, i.e. for setting the actual heating circuit temperature according to the target heating circuit temperature. The invention also relates to a control device set up to carry out the method described below or parts thereof.

From an energetic point of view, a situation in which the heat generator flow temperature is selected as low as possible is preferred when controlling the heating system. This is done by controlling the heating system. For this purpose, the heat generator flow temperature in heating mode is selected so that it exceeds the target heating circuit temperature just enough for a heat transfer medium circulating in the heating circuit to be heated to the target heating circuit temperature. The same applies to all heating circuits if there is more than one heating circuit. The heat generator typically heats up when a heating control system detects that the actual heating circuit temperature falls below the target heating circuit temperature by an adjustable amount and the actual heating circuit temperature should be increased, but the heat generator flow temperature is too low to generate the actual heating circuit temperature .

In a control system that is particularly optimal for condensing boilers, the heat generator flow temperature can be selected so that the condensing boiler heats evenly over the long term and provides such a heat output that the actual heating circuit temperature can be maintained in all heating circuits. If the heat generator flow temperature exceeds the target heating circuit temperature beyond a parameterizable value, the heat generator switches off until after-heating has to be carried out as described above in order to maintain the target heating circuit temperature.

The mixer mixes the heat carrier from the heat generator (with the heat generator flow temperature), if necessary with the heat carrier from the heating return (which has a lower temperature) in order to set the heating circuit target temperature as the actual heating circuit temperature. This is usually done by a control that monitors the deviation of the actual heating circuit temperature from the target heating circuit temperature and acts on the mixer in the heating circuit via a manipulated variable so that the actual heating circuit temperature corresponds to the target heating circuit temperature.

This is a preferred heating control with which the invention can be used. However, it is not necessarily limited to such a control or regulation concept.

In heating systems for building heating and hot water preparation with a heat generator, it is provided that the heat generator heats a heat transfer medium to a heat transfer flow temperature and transfers it to the building heating and hot water preparation via a flow. The heat transfer medium flows via a return from the building heating system (i.e. from the heating circuits) and from the hot water preparation after the thermal energy has been released in the systems (building heating, hot water supply) back to the heat generator, which heats the heat transfer medium again.

The efficiency of a condensing boiler preferred according to the invention is essentially determined by the heat generator return temperature of the heat transfer medium that is fed to the heat generator for heating. The return consists of the building heating return (all heating circuits) and the hot water production return (the charging circuit of the hot water storage tank).

In order to achieve a high heating efficiency of the condensing boiler, the return temperature of the heat carrier returned to the heat generator should be as low as possible, preferably in the range between 20 ° C and 40 ° C and in any case not exceed the gross calorific value limit temperature of about 57 ° C. Above this temperature, the efficiency gain of the condensing technology is only small. It is therefore advantageous to select the heating circuit flow temperature (heating circuit target temperature) in such a way that the heat output emitted in the heating circuit cools the heat transfer medium close to room temperature. The condensing boiler then generates the required heat output in heating mode and runs continuously with a high level of efficiency.

The return temperature from the hot water generation depends on the flow temperature and the volume flow in the charging circuit as well as the charging status and the type of hot water storage tank that may be present. The return temperature from the hot water preparation is typically significantly higher than the return temperature of the heating circuit. The efficiency of the condensing boiler is therefore significantly lower during hot water preparation than in heating mode.

A condensing boiler in the sense of this text is not only understood to mean a condensing boiler in the sense described above, the efficiency of which depends significantly on the return temperature of the heat carrier heated in the heat generator. Under a condensing boiler in the sense of this text is generally understood to be a heat generator that can be operated more efficiently in heating operation of a building heating system than in hot water preparation, which often requires higher heat generator temperatures than heating operation. Condensing boilers in the sense of this text can be heat generators that generate heat locally by converting final energy (e.g. oil, gas, pellets) in a boiler, block-type thermal power station, heat pump or similar, or draw heat from a district or local heating network.

Often, heating systems are operated with heating mode and hot water preparation with a hot water priority switch. Such a hot water priority circuit is supported by every common heating regulation or heating control. Here, the heat supply to the heating circuit is stopped while the domestic water is being heated during hot water preparation. The temperature of the heat generator (boiler temperature or heat generator flow temperature) is increased and the drinking or service water in the hot water storage tank is heated up. When the domestic water temperature in the domestic hot water storage tank has reached the target domestic hot water temperature, a follow-up phase of usually a few minutes is activated, during which the heat generator can transfer most of its residual heat to the domestic hot water storage tank when it is switched off. Then the charging branch for hot water generation is switched off and the heating circuit for heating mode is switched on again.

In this solution, which is often used in the prior art, the heat generation for hot water preparation and the heat generation for the heating operation (working circuit supply) are therefore completely separated. In the manner already described, the heat energy for supplying the heating circuit is generated at a comparatively low heat generator flow temperature. The residual heat remaining in the heat generator after hot water preparation, which comes from less efficient operation of the heat generator, still flows into the heating circuit before it is returned to the energy-efficient one Way can be operated at the lower temperature level (with suitable return temperatures for the condensing technology). This means that some of the space heating energy is generated in a less energy-efficient manner. This proportion is kept as low as possible by the hot water priority circuit.

A disadvantage of the hot water priority circuit is that the building heating or its heating circuit or heating circuits are not supplied with heat for the duration of the hot water preparation. Depending on the size of the hot water storage tank and / or the hot water requirement in the building, this time when the building heating is not supplied with heat can be 20 to over 40 minutes. With some heating regulators, the heating pump is switched off during hot water preparation, which can be perceived by the residents of the building as a failure of the heating system, especially if a cooled radiator is to be put into operation during this time. Other heating controllers close the mixer in the heating circuit, but let a heating circuit pump continue to run. The heating circuit is then operated without any heat supply. This also leads to severe cooling, but is not perceived directly as a failure of the heating due to the perceptible flow of the heat transfer medium in the radiator.

This disadvantage of room heating comfort can be remedied by deactivating the hot water priority circuit. The heating circuit is operated continuously, even during hot water preparation. However, this mode of operation has the disadvantage that the entire room heating energy with which the heating circuit is supplied during hot water preparation is generated in a less energy-efficient operating point of the heat generator.

In any case, it is disadvantageous that the heat generator is not operated in an energy-efficient manner during hot water preparation and during the transition from hot water preparation to heating mode.

In the article "More profit from the heat pump", IKZ-Nachrichten, edition 20/2004, page 40ff. describes an optimization of domestic water operation and heating operation with a mixer manifold in which a special multi-way mixer is used. This special hydraulic circuit also enables the heating and domestic water heating to be operated in parallel. In a system with a hot water storage tank and a heating circuit, the multi-way mixer intercepts the still high-temperature return behind the hot water storage tank and first feeds it into the heating circuit of the building heating system (i.e. the flow of the heating circuit) before it is fed into the return of the heat generator. This is effective, but requires the use of a special multi-way mixer, which must also be controlled accordingly as part of the heating control. Retrofitting in existing heating systems is costly because structural measures are always required.

Against this background, the object of the invention is to increase the energy efficiency of a heating system with, in particular, a condensing boiler as a heat generator, building heating and hot water preparation in a simple manner.

This object is achieved according to the invention with the features of claims 1 and 6. For this purpose, in a method of the type mentioned at the outset, it is provided in particular that a regular heating circuit setpoint temperature in heating mode (also referred to as the setpoint flow temperature of the heating circuit) is reduced by a configurable value during hot water preparation, in particular at the start of hot water preparation, and is increased again after hot water preparation the regular heating circuit target temperature of heating mode is reset. In other words, the regular heating circuit target temperature (after reducing the heating circuit target temperature during hot water preparation) is set again after hot water preparation. The regular heating circuit setpoint temperature can, for example, be taken from a heating curve or another control and / or regulation.

This ensures that the mixer in the heating circuit, which is provided for setting the actual heating circuit temperature according to the target heating circuit temperature, closes when the target heating circuit temperature is reduced or throttles the flow of the warm heat transfer medium through the heating circuit.

During the hot water preparation, little or no heat energy is released from the heat generator into the heating circuit. The energy generated by the heat generator is essentially available for hot water preparation, with the heating circuit still being supplied with heat at least in reduced mode for a longer period of hot water preparation in order to prevent the heating circuit and the building from cooling down completely. The lowering of the heating circuit target temperature should take place immediately with the hot water preparation, at the latest as soon as the start of hot water preparation is recognized. Because, according to the solution proposed according to the invention, the heating circuit is not disconnected from a heat supply for the entire duration of the hot water preparation, as would be the case with a priority circuit, the method according to the invention is also referred to as "soft priority circuit". Particularly preferred radiator heaters are provided in the heating circuit, in which the method is particularly effective and offers the user a significant gain in comfort while at the same time optimizing the efficiency of the heat generation.

In a preferred embodiment of the proposed method, the heating circuit setpoint temperature can be reduced before the heat generator flow temperature is increased during the hot water preparation. The heating circuit setpoint temperature can preferably be reduced immediately before the heat generator flow temperature is increased. In this context, direct means that after the heating circuit setpoint temperature has been reduced, the controller only waits for an actuating time during which it fully or partially closes the mixer. After this setting time, the heat generator flow temperature can be increased immediately. This is typically done in the context of hot water preparation, in which the warm water is to be generated as quickly as possible and therefore the heat generator flow temperature is selected as high as possible; Heat generator flow temperatures between 70 ° C and 90 ° C are often reached, for example in the order of 80 ° C.

After the setting time, the mixer is usually closed because the actual heating circuit temperature is significantly higher than the (now reduced) target heating circuit temperature and there is therefore no heat demand in the heating circuit. If the mixer is closed before the heat generator flow temperature is increased, an additional heat surge into the heating circuit is avoided. The heating circuit first cools down by the specified value before heat energy is supplied again (by opening the mixer to a suitable extent). According to one embodiment of the invention, the reduction in the target heating circuit temperature can be carried out as a "night-time lowering command" and thus analogous to a night-time lowering, with which the target heating circuit temperature is lowered during the residents' usual sleeping times or periods of non-use in office buildings. Instead of a usual night-time reduction, a temperature value for the reduction of the heating circuit setpoint temperature can also be specified as a parameter, for example in the order of about -10 K to -15 K or a relative reduction in the heating circuit overtemperature of up to about 25% the current heating circuit overtemperature. The excess temperature is the difference between the heating circuit flow temperature and the average building temperature.

In addition, it can optionally be provided according to the invention that the duration of the reduction of the heating circuit target temperature is limited during hot water preparation and the regular heating circuit target temperature is set again at the latest after the duration has elapsed, even if the hot water preparation is not yet completed. This maximum duration can preferably be configured, that is to say can be specified by the user. If this possibly parameterizable maximum duration, for example in the order of magnitude of 45 minutes to 1 hour, is exceeded, this variant of the proposed method according to the invention raises the target heating circuit temperature (target flow temperature) back to its regular value, in particular corresponding to the heating curve. This avoids insufficient supply or cooling of the building beyond the normal duration of hot water preparation if hot water preparation should take an unusually long time.

In a further embodiment, the duration of the reduction in the target heating circuit temperature can be learned or determined from the usual duration of hot water preparation in the building by recording the duration of hot water preparation over a certain period, ie several cycles of hot water preparation, and determining an average duration , whereby the duration of the reduction of the heating circuit target temperature is selected as a multiple of the determined average duration (of the hot water preparation). The multiple can be determined by a factor that is a whole or rational number greater than 1, i.e. for example 1.5 times the determined average duration.

Since the hot water preparation is often specified by the control of the heating system, the start and end time of the hot water preparation are the control known, so that the duration of the hot water preparation can be determined by a simple time difference. The average duration is particularly preferably determined in several hot water preparation cycles over a certain period of time, which is preferably at least one day or several days up to a week. The determination of the average duration in one week records the typical practices of hot water consumption by users in different situations. This forms a statistically meaningful basis for determining the average duration of hot water generation. This can be determined automatically by the system or the control. For example, 1.5 to 2 times the average duration can be selected as a multiple of the average duration in order to limit the duration of the reduction of the heating circuit target temperature. In addition, an absolute maximum duration, for example 1 hour, can be specified. This prevents the building from cooling too much, even in the cold season.

Since the increase in efficiency in heating operation, adjacent to hot water preparation, is only achieved in classic condensing boilers if the temperature of the heat transfer medium fed back to the heat generator in the return does not exceed the calorific value limit temperature already explained, it can be provided in a useful optional embodiment of the proposed method that The heating circuit return temperature is measured and the reduction in the heating circuit setpoint temperature is returned (ie ended or reduced) if the heating circuit return temperature is above the gross calorific value limit temperature. In typical condensing boilers, the increase in efficiency depends on the level of the return temperature of the heat transfer medium in the heating circuit. If this temperature is above a calorific value limit temperature, which can be around 57 ° C., for example, the gain in efficiency of the proposed method is only slight. The reduction in the heating circuit target temperature proposed according to the invention can then be reduced or reduced, down to the value 0, at which the heating circuit target temperature corresponds to the regular heating circuit target temperature as it is is predetermined, for example, by a heating curve. In this case, the heat would not be generated more efficiently in heating mode than in hot water preparation.

According to a further aspect of the invention, this also includes a control device for controlling a heating system with preferably a condensing boiler as a heat generator, with at least one heating circuit for heating the building and with hot water preparation for heating domestic water to a target hot water temperature, the domestic water e.g. in a hot water storage tank the hot water preparation can be saved. The proposed control device has interfaces for controlling the heat generator, the at least one heating circuit and the hot water preparation, as well as a computing device which is set up to carry out the above-described method or parts thereof. The computing device can be located both in the control unit on site (locally) and, for example, in an IT cloud or a data center (remote). If the computing device is in the IT cloud or in a data center (e.g. in a central IT system), parameters for controlling the heat generator can be downloaded to the control device, for example via a cellular data transmission interface.

The control device can be integrated into the usually existing control device of the heating system and have internal interfaces for controlling the heat generator, the at least one heating circuit and the hot water preparation. According to the invention, the control device can also be provided as a device separate from the heating system and connected to the control device of the heating system via a control interface, for example a suitable bus or other interface via which the aforementioned interfaces can be implemented.

In a simple embodiment, the control device can carry out a flow temperature simulation and thus indirectly bring the existing control device of the heating system to adapt the flow temperature.

Preferably, temperature sensors for detecting the heat generator flow temperature, the heat generator return temperature, the heating circuit flow temperature, the heating circuit return temperature and / or the actual hot water temperature can be connected to the interfaces of the control unit. This enables the control unit to have a simple and precise control for carrying out the method proposed according to the invention.

A further embodiment of the invention can take place in that the control device directly controls a mixer in the heating system. The control signal of the original heating controller can be recorded, interpreted and forwarded to the mixer unchanged or manipulated by the control unit. An optimized control of the mixer can take place on the basis of measured temperature values or can be achieved with knowledge of the mixer running time and mixer setting.

Further advantages, features and possible applications of the invention can also be found in the following description of exemplary embodiments and the drawing. All the features described and / or shown in the figures belong together or in any technically meaningful combination to the subject matter of the invention, regardless of their combination in the described or illustrated exemplary embodiments or in the claims.

• Fig. 1 schematisch ein erfindungsgemäßes Steuergerät gemäß einer Ausführungsform der Erfindung, das an eine Heizungsanlage angeschlossen ist;
• Fig. 2 ein schematisches Ablaufdiagramm eines erfindungsgemäßen Verfahrens gemäß einer Ausführungsform der Erfindung;
• Fig. 3 schematisch den zeitlichen Temperarturverlauf der WärmeerzeugerVorlauftemperatur ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}},$
  
  der Warmwasserbereitungs-Rücklauftemperatur ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{RL}},$
  
  der Heizkreis-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}},$
  
  der Heizkreis-Rücklauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}$
  
  und der Heizkreis-Solltemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{soll}}$
  
  bei und nach der Warmwasserbereitung ohne Anwendung des erfindungsgemäßen Verfahrens (Stand der Technik);
• Fig. 4 schematisch den zeitlichen Heizleistungsverlauf für die Warmwasserbereitung und den Heizbetrieb bei und nach der Warmwasserbereitung ohne Anwendung des erfindungsgemäßen Verfahrens (Stand der Technik);
• Fig. 5 schematisch den zeitlichen Temperarturverlauf der WärmeerzeugerVorlauftemperatur ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}},$
  
  der Warmwasserbereitungs-Rücklauftemperatur ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{RL}},$
  
  der Heizkreis-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}},$
  
  der Heizkreis-Rücklauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}$
  
  und der Heizkreis-Solltemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{soll}}$
  
  bei und nach der Warmwasserbereitung bei Anwendung des erfindungsgemäßen Verfahrens gemäß einer Ausführungsform;
• Fig. 6 schematisch den zeitlichen Heizleistungsverlauf für die Warmwasserbereitung und den Heizbetrieb bei und nach der Warmwasserbereitung bei Anwendung des erfindungsgemäßen Verfahrens gemäß einer Ausführungsform ;

Show it:

• 1 schematically shows a control device according to the invention according to an embodiment of the invention, which is connected to a heating system;
• 2 shows a schematic flow diagram of a method according to the invention according to an embodiment of the invention;
• 3 schematically shows the temperature profile of the heat generator supply temperature over time ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}},$
  
  the water heating return temperature ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{RL}},$
  
  the heating circuit flow temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}},$
  
  the heating circuit return temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}$
  
  and the target heating circuit temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$
  
  during and after the hot water preparation without using the method according to the invention (prior art);
• 4 schematically shows the heating power curve over time for the hot water preparation and the heating operation during and after the hot water preparation without using the method according to the invention (prior art);
• Fig. 5 schematically shows the temperature profile of the heat generator supply temperature over time ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}},$
  
  the water heating return temperature ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{RL}},$
  
  the heating circuit flow temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}},$
  
  the heating circuit return temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}$
  
  and the target heating circuit temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$
  
  during and after the water heating when using the method according to the invention according to one embodiment;
• 6 schematically shows the heating output curve over time for the hot water preparation and the heating operation during and after the hot water preparation when the method according to the invention is used according to one embodiment;

In Figure 1 an inventive control device 1 is shown according to an embodiment of the invention. The control device 1 is connected to components of a heating system 100 of a building via interfaces 2, 3, 4, 5. In the control device 1 there is also a computing device (not shown) which is set up to carry out the method proposed according to the invention for controlling the heating system 100. Alternatively, the computing device can be arranged in an IT cloud or in a data center, in which case a communication unit (not shown) is located in the control device 1 instead of the computing device.

direkt beeinflussen. Über die Schnittstellen 2, 3, 4, 5 werden Steuersignale ausgegeben. Dies ist in der Figur 1 als gestrichelte Linie dargestellt.The heating system 100 has a heat generator 101, preferably designed as a condensing boiler, a heating circuit 111 for heating the building and a hot water preparation system 121 for heating domestic water to a target hot water temperature. The domestic water can be drawn off by the building's users. Typically, the water heater 121 also includes an in Figure 1 water storage tank, not shown, in which the heated domestic water is stored. Interface 2 connects control device 1 to heat generator 101. Interface 3 connects control device 1 to hot water preparation 121. Interface 4 connects control device 1 to heating circuit 111. Optional interface 5 connects control device 1 to mixer 112 of heating circuit 111 Via the interface 5, the control device 1 can set the mixer 112 by activating the electrically operated mixer motor or servomotor and thus the heating circuit flow temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

affect directly. Control signals are output via interfaces 2, 3, 4, 5. This is in the Figure 1 shown as a dashed line.

aus. Die Temperaturen sind in Figur 1 an den jeweiligen Positionen, an denen sie durch einen Temperatursensor messbar sind, durch einen Punkt mit Bezeichnung dargestellt. Diese Punkte können auch Temperatursensoren repräsentieren, die bspw. über die Schnittstellen 2, 3, 4 (und eine nicht dargestellte Signalübertragung) durch die Steuerung 1 abfragebar sind.The heating circuit 111 is connected to the heat generator flow 102 via a mixer 112. Via the heat generator supply line 102, the heat generator 101 emits the heated heat transfer medium with a heat transfer medium supply temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

out. The temperatures are in Figure 1 at the respective positions at which they can be measured by a temperature sensor, represented by a point with a designation. These points can also represent temperature sensors which, for example, can be queried by the controller 1 via the interfaces 2, 3, 4 (and a signal transmission (not shown)).

wird einem ersten Eingang des Mischers 112 zugeführt. Ein zweiter Eingang des Mischers 112 ist mit dem Heizkreis-Rücklauf 114 verbunden, um den Wärmeträger aus dem Wärmeerzeuger-Vorlauf 102 durch Beimischen des (abgekühlten) Wärmeträgers aus dem Heizkreis-Rücklauf 114 abzukühlen und in dem Heizkreis-Vorlauf 113 eine der Heizkreis-Solltemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{soll}}$

entsprechende Heizkreis-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

einzustellen. In Figur 1 ist die Heizkreis-Solltemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{soll}}$

nicht eingezeichnet.The heated heat transfer medium with the heat transfer medium flow temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

is fed to a first input of the mixer 112. A second input of the mixer 112 is connected to the heating circuit return 114 in order to cool the heat transfer medium from the heat generator supply 102 by mixing in the (cooled) heat transfer medium from the heating circuit return 114 and in the heating circuit supply 113 one of the heating circuit target temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$

corresponding heating circuit flow temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

to adjust. In Figure 1 is the target heating circuit temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$

not shown.

gespeicherte Wärmeenergie über Wärmetauscher, vorzugsweise Radiator-Wärmetauscher (klassische Heizkörper), teilweise abgegeben. Dabei kühlt sich der Wärmeträger auf die Rücklauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}$

ab. Über den Wärmeerzeuger-Rücklauf 103 wird der Wärmeträger zu dem Wärmeerzeuger 101 zur erneuten Erwärmung rückgeführt.In the heating circuit 111 the in the heat transfer medium with the flow temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

Stored heat energy via heat exchangers, preferably radiator heat exchangers (classic radiators), partially released. The heat transfer medium cools down to the return temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}$

from. Via the heat generator return 103, the heat transfer medium is returned to the heat generator 101 for renewed heating.

der Warmwasseraufbereitung 121 zugeführt, in der der Wärmeträger die Wärmeenergie über einen Wärmetauscher an das Brauchwasser überträgt, das üblicherweise in einem nicht dargestellten isolierten Wärmespeicher gespeichert wird und zum Zapfen durch den Benutzer zur Verfügung steht. Nach der Abgabe der Wärmeenergie durch den Wärmeträger an das Brauchwasser wird der Wärmeträger über den Warmwasserbereitungs-Rücklauf 122 in den Rücklauf 103 des Wärmeerzeuger 101 rückgeführt. Im Vorlauf ist die Warmwasserbereitung 121 unmittelbar an den Wärmeerzeuger-Vorlauf 102 angeschlossen.The heat transfer medium is used to heat domestic water with the heat transfer medium flow temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

the hot water preparation 121 supplied, in which the heat transfer medium transfers the thermal energy via a heat exchanger to the domestic water, which is usually stored in an insulated heat storage device (not shown) and is available for tapping by the user. After the thermal energy has been released by the heat transfer medium to the domestic water, the heat transfer medium is returned to the return line 103 of the heat generator 101 via the hot water production return 122. In the flow, the hot water preparation 121 is directly connected to the heat generator flow 102.

In a large number of heating systems 100 with one or more heating circuits 111 and hot water preparation 121, hot water preparation 121 is carried out in a so-called priority mode in which mixer 112 of heating circuit 111 is closed so that heating circuit 111 does not receive any heat during hot water preparation 121.

In some cases, it is also known to carry out the hot water preparation 121 and the heating operation in the heating circuit or circuits 111 of the building heating system in parallel.

It should be noted at this point that in Figure 1 For the sake of clarity, only one heating circuit 111 is shown. In buildings, however, more than one heating circuit 111 can also be provided; the multiple heating circuits 111 are then connected in a comparable manner, preferably each via a separate mixer 112, to the heat generator supply line 102.

und die Heizkreis-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

fallen im Gleichklang von einem Temperaturwert υ - in dem Beispiel - größer 50 °C auf einen Temperaturwert von etwa - in dem Beispiel - 45 °C ab, der in der Nähe der Heizkreis-Rücklauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}$

liegt. Die Heizkreis-Solltemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

liegt - in dem Beispiel - bei 50 °C. Zum Zeitpunkt t1 wird parallel zum Heizbetrieb auch die Warmwasserbereitung aktiviert. Dazu wird die Wärmeerzeuger-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

bis - in dem Beispiel - auf etwa 85 °C erhöht und der Wärmeträger der Warmwasserbereitung 121 zugeleitet. Dort überträgt er seine Wärmeenergie teilweise auf das Brauchwasser und verlässt die Warmwasserbereitung 121 mit der Wärmewasserbereitung-Rücklauftemperatur ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{RL}},$

die nur geringfügig niedriger ist als die Wärmeerzeuger-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

und signifikant größer ist als die Heizkreis-Rücklauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}\mathrm{.}$

The temperature curve in parallel operation of hot water preparation 121 and heating operation in heating circuit 111 is shown in Figure 3 shown. At the beginning of the time axis t, the heating system 100 is still in pure heating mode (left side of the time axis before time t1). The heat generator flow temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

and the heating circuit flow temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

fall in unison from a temperature value υ - in the example - greater than 50 ° C to a temperature value of around - in the example - 45 ° C, which is close to the heating circuit return temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}$

lies. The target heating circuit temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

is - in the example - at 50 ° C. At time t1, hot water generation is also activated in parallel to heating mode. The heat generator flow temperature is used for this ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

until - in the example - increased to about 85 ° C and the heat transfer medium of the hot water preparation 121 is fed. There it partially transfers its thermal energy to the domestic water and leaves the hot water preparation 121 with the heating water preparation return temperature ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{RL}},$

which is only slightly lower than the heat generator flow temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

and is significantly higher than the heating circuit return temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}\mathrm{.}$

These mentioned temperatures correspond to possible temperature values that can occur in typical systems. The invention is not intended to be restricted to these temperature values, which the person skilled in the art will adapt as required.

über das Heizkreis-Solltemperatur-Niveau an. Es dauert eine gewisse Zeit, bis der Mischer 112 in der Lage ist, die Heizkreis-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

an die Solltemperatur anzupassen. Es kommt also zu einem Wärmeschub 115 im Heizkreis 111, der durch einen Anstieg der Heizkreis-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

gekennzeichnet ist.Due to the - based on the heating circuit 111 - excess heat in the heat generator flow 102, the heating circuit flow temperature rises first ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

via the heating circuit target temperature level. It takes a certain time until the mixer 112 is able to maintain the heating circuit flow temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

to adapt to the target temperature. There is therefore a heat surge 115 in the heating circuit 111, which is caused by an increase in the heating circuit flow temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

is marked.

wird auf dem Temperaturniveau von gut 80 °C bis zum Zeitpunkt t2 gehalten, zu dem die Brauchwasser-Isttemperatur ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{ist}}$

der gewünschten Brauchwasser-Solltemperatur ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{soll}}$

entspricht. Auch dieser Temperaturwert ist nur beispielhaft zu verstehen. Es ist jedoch wünschenswert, dass die Wärmeerzeuger-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

bei der Warmwasserbereitung 121 gegenüber dem Heizbetrieb signifikant erhöht ist, damit das Brauchwasser schnell erwärmt wird. Eine Erhöhung der Wärmeerzeuger-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

gegenüber der Warmwasser-Solltemperatur um beispielsweise 15 K bis 25 K kann durchaus angestrebt sein.The heat generator flow temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

is kept at the temperature level of a good 80 ° C until time t2, at which the actual domestic water temperature ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{is}}$

the desired hot water target temperature ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{should}}$

corresponds to. This temperature value is also only to be understood as an example. However, it is desirable that the heat generator flow temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

is significantly increased in the hot water preparation 121 compared to the heating mode, so that the domestic water is heated quickly. An increase in the heat generator flow temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

15 K to 25 K compared to the target hot water temperature, for example, can certainly be aimed for.

absinkt und sich der Heizkreis-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

annähert. Mit anderen Worten kühlt also der Wärmeträger im Vorlauf 102 des Wärmeerzeugers 101 langsam ab. Zum Zeitpunkt t3 beginnt dann wieder der reine (reguläre) Heizbetrieb, d.h. der Heizbetrieb ohne zusätzlichen Wärmeeintrag aus der Warmwasserbereitung 121.At this point in time t2, the heat generator 101 is also switched off, so that the heat generator flow temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

drops and the heating circuit flow temperature increases ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

approximates. In other words, the heat carrier cools slowly in the flow line 102 of the heat generator 101. Then begins again at time t3 the pure (regular) heating operation, ie the heating operation without additional heat input from the hot water preparation 121.

In Figure 4 is the heating power W for the in Figure 3 The temperature curve shown is shown, with the heating output shown separately for the hot water preparation and the heating circuit. It can be seen that the thermal energy emitted during the hot water preparation 121 (integrated heating power Ẇ between times t1 and t2; the integrated heating power is also referred to as the amount of heat) is approximately twice as high as the heat energy 116 emitted into the heating circuit 111.

After the end of hot water preparation 121 at time t2, the residual heat remaining in the heating system is still released as heating energy 117 into heating circuit 111 before pure heating operation begins again at time t3.

aufgrund der deutlich erhöhten Warmwasserbereitung-Rücklauftemperatur ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{RL}}$

so hoch, dass die Effizienzsteigerung der Brennwerttechnologie nicht genutzt werden kann. In den Heizkreis 101 wird somit in dem Zeitraum t1 bis t3 Wärme abgegeben, die ineffektiver erzeugt wurde als im reinen Heizbetrieb.However, the heat generator return temperature is up to this point in time ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{RL}}$

due to the significantly increased hot water heating return temperature ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{RL}}$

so high that the increased efficiency of condensing technology cannot be used. Heat that was generated more ineffectively than in the pure heating mode is thus given off into the heating circuit 101 in the time period t1 to t3.

In order to generate more heat energy at a more effective operating point of the heat generator 101, the invention proposes a method for controlling a heating system, the basic features of which are shown in a schematic flow chart Figure 2 are shown. It should be noted that only the basic ideas of the invention are listed here for the sake of clarity. The optional elements already described can be incorporated into this process sequence by the person skilled in the art.

um einen vorgegebenen Wert. Durch das Absenken der Heizkreis-Solltemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{soll}}$

schließt der Mischer 112 und koppelt den Heizkreis 111 von dem Wärmeerzeuger 101 ab bzw. vermindert den Durchfluss des Wärmeträgers in dem Heizkreis 111. Dies erfolgt in Verfahrensschritt 53 automatisch.The start 51 of the illustrated method 50 for controlling a heating system lies in method step 52 in the recognition of a need for hot water preparation and the lowering of the heating circuit setpoint temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$

by a given value. By lowering the target heating circuit temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$

the mixer 112 closes and decouples the heating circuit 111 from the heat generator 101 or reduces the flow of the heat transfer medium in the heating circuit 111. This takes place automatically in method step 53.

in Verfahrensschritt 54 erhöht, um das Brauchwasser möglichst schnell auf die Brauchwasser-Solltemperatur ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{soll}}$

zu erwärmen. Letzteres erfolgt bei der Warmwasserbereitung in Verfahrensschritt 55.The result is the heat generator flow temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

increased in method step 54 in order to bring the domestic water to the target domestic water temperature as quickly as possible ${\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{should}}$

to warm up. The latter takes place during the hot water preparation in process step 55.

wieder auf den regulären Wert, d.h. den Wert vor der Warmwasserbereitung, angehoben. Damit endet das Verfahren in Verfahrensschritt 57.As soon as the domestic water has reached the desired temperature, the end of the hot water generation and the target heating circuit temperature are recognized in method step 56 ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$

raised again to the regular value, ie the value before hot water generation. The method thus ends in method step 57.

zwischen den Zeitpunkten t1 und t2 während der Warmwasserbereitung. Aufgrund des Schließens des Mischers 112 im Anschluss an das Absenken der Heizkreis-Solltemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{soll}}$

erhöht sich die Heizkreis-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

trotz der Erhöhung der Wärmeerzeuger-Vorlauftemperatur ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

kaum. Lediglich um ein starkes Abkühlen des Gebäudes zu vermeiden, mischt der Mischer 112 einen kleinen Teil der durch den Wärmeerzeuger 101 erzeugten Wärmeleistung in den Heizkreis 111 ein. Mit dem Ende der Warmwasserbereitung wird der Heizkreis-Sollwert ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{soll}}$

wieder auf das Vorniveau, d.h. den beispielsweise durch eine Heizkurve vorgegebenen regulären Heizkreis-Sollwert ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{soll}}$

angehoben. In dem dargestellten Beispiel wird der Heizkreis-Sollwert ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{soll}}$

um 10 °C abgesenkt, von 50 °C auf 40 °C.The temperature profile resulting from this process accordingly Figure 3 is in Figure 5 shown. The lowering of the target heating circuit temperature can be seen ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$

between times t1 and t2 during hot water generation. Due to the closing of the mixer 112 following the lowering of the heating circuit setpoint temperature ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$

the heating circuit flow temperature increases ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}$

despite the increase in the heat generator flow temperature ${\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}$

barely. The mixer 112 mixes a small part of the heat output generated by the heat generator 101 into the heating circuit 111 merely to avoid excessive cooling of the building. At the end of hot water generation, the heating circuit setpoint is set ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$

back to the pre-level, ie the regular heating circuit setpoint specified, for example, by a heating curve ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$

raised. In the example shown, the heating circuit setpoint is ${\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}$

lowered by 10 ° C, from 50 ° C to 40 ° C.

How Figure 6 It can be seen that the heat energy 116 released into the heating circuit during hot water preparation (ie in the time period t1 to t2) is compared to Figure 4 , significantly reduced. In this way, significantly less ineffectively generated thermal energy is fed into the heating circuit 111.

List of reference symbols:

1

Control unit

2

interface

3

interface

4th

interface

5

interface

50

Method for controlling a heating system

51

Start of the process

52

Recognizing the need for hot water generation and lowering the target heating circuit temperature

100

Heating system

101

Heat generator

102

Heat generator flow

103

Heat generator return

111

Heating circuit for heating the building

112

mixer

113

Heating circuit flow

114

Heating circuit return

115

Warmth boost

116

Thermal energy released in the heating circuit during hot water preparation (period t1 to t2)

117

Thermal energy released in the heating circuit after hot water preparation (period t2 to t3)

121

Water heating

122

Water heating return

Claims (9)

Method for controlling a heating system (100) with a heat generator (101), with at least one heating circuit (111) for heating the building and with hot water preparation (121) for heating domestic water, with a heat generator flow temperature $\left({\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}\right)$

greater than or equal to the target heating circuit temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}\right)$

is selected and a mixer (112) for setting a heating circuit flow temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}\right)$

is provided, characterized in that a regular heating circuit target temperature during hot water preparation $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}\right)$

is reduced by a configurable value in heating mode and back to the regular heating circuit setpoint temperature after hot water generation (121) $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}\right)$

of heating operation is reset. The method according to claim 1, characterized in that reducing the heating circuit setpoint temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}\right)$

takes place before the heat generator flow temperature during hot water preparation (121) $\left({\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}\right)$

is increased. Method according to Claim 1 or 2, characterized in that the duration of the reduction in the heating circuit setpoint temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{Sol}}\right)$

is limited during hot water generation (121) and the regular heating circuit setpoint temperature after the duration has elapsed $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{Sol}}\right)$

is set again. Method according to claim 3, characterized in that the duration of the reduction in the heating circuit setpoint temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}\right)$

is learned from the usual duration of a hot water preparation (121) in the building by recording the duration of the hot water preparation (121) over a certain period and a average duration is determined, whereby the duration of the reduction of the heating circuit target temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}\right)$

is chosen as a multiple of the determined average duration. Method according to one of the preceding claims, characterized in that the heating circuit return temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}\right)$

measured and the reduction in the target heating circuit temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{should}}\right)$

is returned when the heating circuit return temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}\right)$

is above a gross calorific value limit temperature. Control device for controlling a heating system (100) with a heat generator (101), with at least one heating circuit (111) for heating the building and with hot water preparation (121) for heating domestic water, the control device (1) interfaces (2, 3, 4) for controlling the heat generator (101), the at least one heating circuit (111) and the hot water preparation (121), and with a computing device, characterized in that the computing device is set up to carry out the method according to one of Claims 1 to 5. Control device according to Claim 6, characterized in that temperature sensors for detecting the heat generator flow temperature are connected to the interfaces (2, 3, 4) $\left({\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{VL}}\right),$

the heat generator return temperature $\left({\mathit{\vartheta }}_{\mathit{WE}}^{\mathit{RL}}\right),$

the heating circuit flow temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{VL}}\right),$

the heating circuit return temperature $\left({\mathit{\vartheta }}_{\mathit{HZ}}^{\mathit{RL}}\right)$

and / or the actual hot water temperature $\left({\mathit{\vartheta }}_{\mathit{WW}}^{\mathit{is}}\right)$

are connectable. Control device according to Claim 6 or 7, characterized in that the computing device is part of an IT cloud, the method according to one of Claims 1 to 5 is carried out in a cloud application and the results are transmitted back to the control device (1). Control device according to claim 6 or 7, characterized in that the computing device is designed as part of a central IT system, the method according to one of claims 1 to 5 is carried out in the central IT system and the results are transmitted back to the control device (1) become.

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