DE102022129751A1 - Method for operating a sanitary fitting and sanitary fitting - Google Patents

Abstract

The invention relates to a method for operating a sanitary fitting (1), wherein the sanitary fitting (1) comprises at least one hot water pipe (2) with a first control valve (3), a cold water pipe (4) with a second control valve (5) and a mixed water pipe (6) connected thereto, which has an outlet (7) with a fixed or with a variable outlet resistance and a characteristic, further comprising a minimum number of sensors (8, 9, 10) by means of which certain parameters of the sanitary fitting (1) can be measured, and a control device (11) for detecting and processing the measured values (12) transmitted by the sensors (8, 9, 10); wherein a maximum flow rate (15) is calculated by the method for an operating point (13, 14) of the sanitary fitting (1) selected by a user.The invention additionally relates to a sanitary fitting (1).

Description

The invention relates to a method for operating a sanitary fitting and a sanitary fitting that can be operated by the method. The sanitary fitting is used in particular to provide a liquid as needed to a washbasin, sink, shower and/or bathtub.

Sanitary facilities such as showers, sinks, bathtubs or wash basins are usually supplied with fresh water from a house connection. The fresh water can be provided to the sanitary facility as both cold water and hot water. The sanitary facility usually has a sanitary fitting, which can usually produce mixed water of the desired temperature using the fresh cold water and the fresh hot water and can make it available for use in or at the sanitary facility.

In conventional sanitary fittings, the volume (i.e. the volume flow or the jet hardness) is adjusted when the user changes the flow cross-section in a valve using an actuating element. As a rule, an outlet resistance (e.g. a shower) is connected downstream of the hydraulic resistance of the sanitary fitting. The hydraulic resistance of the sanitary fitting and the outlet resistance together determine the flow of the system. If the resistances are very different, the larger resistance (smaller cross-section) primarily determines the flow. This means that in the lower range of the volume adjustment (valve slightly open) the valve position largely determines the flow, while in the upper range of the volume adjustment (valve wide open) the outlet resistance is often the determining factor. This leads to a non-linear volume adjustment. The effect is even more pronounced if the outlet contains a flow limiter (flow stabilizer) that changes its flow cross-section depending on the pressure.

With an electronic sanitary fitting, the user does not have a direct influence on the installed valves. Instead, a user specification, which he makes on a user interface that can be designed as desired, is used as an input variable in an algorithm that ultimately determines the position of the valves. This basically opens up significantly more options for volume adjustment.

The user can be given visual feedback on the volume setting at the user interface. This can be done by a numerical display that shows a qualitative (e.g. values from 1 to 10 or 0 to 100%) or quantitative (e.g. flow in l/min) value. Alternatively, a pictorial display can be selected.

• • Solche Darstellungen sind dem Nutzer von anderen elektronischen Geräten bekannt,
• • die Darstellung bietet dem Nutzer eine Information, wie weit der Durchfluss/die Strahlhärte noch erhöht werden kann,
• • ein Durchflusswert in l/min [Liter pro Minute] ist für den Nutzer eine schwer einzuordnende Größe,
• • während einer Wellness-Dusche möchte der Nutzer nicht über den Wasserverbrauch nachdenken,
• • der mögliche Durchfluss ändert sich deutlich in Abhängigkeit von den Betriebsbedingungen und den geöffneten Auslässen, sodass sich der Verstellbereich einer quantitativen Verstellung häufig verändern würde.

There are several arguments in favour of choosing a qualitative representation:

• • Such representations are familiar to the user from other electronic devices,
• • the display provides the user with information on how much the flow/jet hardness can be increased,
• • a flow rate in l/min [litres per minute] is a value that is difficult for the user to classify,
• • during a wellness shower the user does not want to think about water consumption,
• • the possible flow varies considerably depending on the operating conditions and the open outlets, so that the adjustment range of a quantitative adjustment would often change.

Based on this, it is an object of the invention to at least partially solve the problems described with reference to the prior art. In particular, a method for operating a sanitary fitting and a sanitary fitting that can be operated using the method are to be proposed, whereby the method can be used to control a volume flow in a way that is as comprehensible as possible for the user.

• a) Betreiben der Sanitärarmatur in einem Betriebspunkt der Sanitärarmatur;
• b) Berechnen eines maximalen Durchflusses für den vorliegenden Betriebspunkt durch die Steuereinrichtung unter der Annahme, dass der maximale Durchfluss dann vorliegt, wenn eines der Ventile (des ersten Ventils und des zweiten Ventils) voll geöffnet ist und das andere Ventil (des ersten Ventils und des zweiten Ventils) eine zur Aufrechterhaltung einer Soll-Temperatur erforderliche Stellung aufweist; wobei anhand der von den Sensoren erfassten Messwerte und anhand der bekannten oder berechneten Charakteristik des Auslasswiderstands
  • • sowie anhand eines Kennwerts des maximal geöffneten ersten Ventils ein maximaler erster Mischwasservolumenstrom berechnet wird;
  • • sowie anhand eines Kennwerts des maximal geöffneten zweiten Ventils ein maximaler zweiter Mischwasservolumenstrom berechnet wird;
• a) Vergleichen der Werte des ersten Mischwasservolumenstroms und des zweiten Mischwasservolumenstroms;
• b) Auswahl des kleineren Wertes und Verwenden dieses Wertes als den maximalen Durchfluss.

A method for operating a sanitary fitting is proposed. The sanitary fitting comprises at least one hot water pipe with a first control valve, a cold water pipe with a second control valve and a mixed water pipe connected thereto (fluidically), which has an outlet with a rigid or variable outlet resistance and a characteristic, furthermore a minimum number of sensors by means of which certain parameters of the sanitary fitting can be measured, and a control device for recording and processing the measured values transmitted by the sensors. The method comprises at least the following steps:

• a) Operating the sanitary fitting at an operating point of the sanitary fitting;
• b) Calculating a maximum flow for the current operating point by the control device, assuming that the maximum flow occurs when one of the valves (the first valve and the second valve) is fully open and the other valve (the first valve and the second valve) is at a position required to maintain a desired temperature. temperature; using the measured values recorded by the sensors and the known or calculated characteristics of the outlet resistance
  • • and a maximum first mixed water volume flow is calculated based on a characteristic value of the maximum open first valve;
  • • and a maximum second mixed water volume flow is calculated based on a characteristic value of the maximum open second valve;
• a) comparing the values of the first mixed water volume flow and the second mixed water volume flow;
• b) Select the smaller value and use this value as the maximum flow.

The above (non-exhaustive) classification of the process steps into a) to d) is primarily intended to serve as a distinction and does not force a sequence and/or dependency. The frequency of the process steps, e.g. during operation of the sanitary fitting, can also vary. It is also possible that process steps overlap one another at least partially. In particular, steps a) to d) are carried out in the order listed.

The characteristic K _{V,out of} the outlet with a fixed or with a variable outlet resistance is in particular calculated or determined or is already known.

In particular, the sanitary fitting comprises so-called continuous valves, by means of which the hot water volume flow and the cold water volume flow can be controlled, so that the mixed water temperature and the desired mixed water volume flow desired by a user can be set for the mixed water pipe.

In such a sanitary fitting, a possible maximum flow occurs especially when one of the valves is fully open and the other valve is in the position necessary to maintain the target temperature.

In particular, in a step e), the control device is used to provide a proportional control of a volume flow that can be controlled by the user and flows out via the outlet based on the known maximum flow for a user of the sanitary fitting.

In particular, in step e), the control device is used to determine, on the basis of the known maximum flow rate, a maximum volume flow rate flowing out via the outlet for the operating point, which corresponds to the maximum flow rate.

• i) Betreiben der Sanitärarmatur in mindestens einem Betriebspunkt (in einem oder in zwei Betriebspunkten, falls erforderlich in mehr als zwei Betriebspunkten) der Sanitärarmatur und Messen oder Bestimmen eines Mischwasservolumenstroms sowie eines Mischwasserdrucks durch die Sensoren;
• ii) Bestimmen der Charakteristik des Auslasswiderstands anhand der in Schritt i) gemessenen Messwerten;
• iii) Hinterlegen der Charakteristik in der Steuereinrichtung;

wobei die Schritte i) bis iii) zeitlich vor den Schritten a) bis d) an der Sanitärarmatur oder an einer Teilsanitärarmatur mit einer Leitung, die den Auslass mit dem starren oder mit dem veränderbaren Auslasswiderstand und der Charakteristik aufweist, durchgeführt werden, wobei die so bestimmte Charakteristik in der Steuereinrichtung der Sanitärarmatur hinterlegt wird.In particular, the procedure (additionally) comprises the following steps:

• (i) operating the sanitary fitting at at least one operating point (at one or two operating points, if necessary at more than two operating points) of the sanitary fitting and measuring or determining a mixed water volume flow and a mixed water pressure by means of the sensors;
• (ii) determining the characteristic of the outlet resistance from the measured values obtained in step (i);
• iii) storing the characteristic in the control device;

wherein steps i) to iii) are carried out prior to steps a) to d) on the sanitary fitting or on a partial sanitary fitting with a line having the outlet with the rigid or variable outlet resistance and the characteristic, wherein the characteristic thus determined is stored in the control device of the sanitary fitting.

In particular, in step i), a mixed water volume flow and a mixed water pressure are measured only indirectly, e.g. using Richmann's mixing rule and/or based on other measured parameters.

• • der Volumenstrom soll sich bei einer Verstellung durch den Nutzer möglichst linear also proportional zum Wert der Vorwahl ändern. Das von herkömmlichen Sanitärarmaturen bekannte Verhalten, dass sich der Durchfluss (der Volumenstrom) bzw. die Strahlhärte im unteren Bereich der Verstellung stark verändert und im oberen Bereich kaum, also nicht proportional bzw. linear, soll vermieden werden;
• • der maximale Wert der Volumenverstellung soll mit dem maximalen bzw. dem maximal möglichen Durchfluss zusammenfallen, damit
  • • einerseits der vom Nutzer gewählte Vorgabewert nicht größer als der maximale Durchfluss sein kann (Linearität im oberen Verstellbereich verletzt),
  • • andererseits der maximal mögliche Durchfluss auch immer ausgewählt werden kann.

It is particularly advantageous to enable a qualitative adjustment (and display) of the volume flow at the sanitary fitting, e.g. in the case of a sanitary fitting for controlling a large shower system). In particular, the following requirements must be met:

• • the volume flow should change as linearly as possible when adjusted by the user, i.e. proportionally to the pre-selected value. The behavior known from conventional sanitary fittings, that the flow (the volume flow) or the jet hardness changes greatly in the lower range of the adjustment and hardly at all in the upper range, i.e. not proportionally or linearly, should be avoided;
• • the maximum value of the volume adjustment should coincide with the maximum or the maximum possible flow, so that
  • • on the one hand, the preset value selected by the user cannot be greater than the maximum flow (linearity in the upper adjustment range is violated),
  • • on the other hand, the maximum possible flow can always be selected.

• • den Eingangsdrücken,
• • den Eingangstemperaturen,
• • der ausgewählten Mischwassertemperatur,
• • den hydraulischen Widerständen der angewählten Auslässe (z. B. Brausen).

In particular, these requirements can only be achieved if the algorithm knows the maximum flow rate. However, this depends on many factors:

• • the input pressures,
• • the inlet temperatures,
• • the selected mixed water temperature,
• • the hydraulic resistances of the selected outlets (e.g. showers).

In known electronic sanitary fittings, this possibility to calculate/predict the maximum flow does not exist, so the stated goals cannot be achieved.

In the present case, the problem mentioned is solved by equipping the (electronic) sanitary fitting used for the process with sensors with which the maximum possible flow rate for the given conditions or for the operating points selected by the user can be calculated or predicted.

• • Eingangsdrücke p_w; p_k
• • Druck im Mischwasserbereich p_m
• • Gesamtdurchfluss bzw. Mischwasservolumenstrom Q_m
• • Eingangstemperaturen ϑ_w; ϑ_k bzw. das benötigte Mischungsverhältnis Q_w/Q_k

For this purpose, the following variables of the hydraulic system in particular must be recorded by sensors or calculated using known hydraulic relationships:

• • Input pressures p _w ; p _k
• • Pressure in the mixed water area p _m
• • Total flow or mixed water volume flow Q _m
• • Inlet temperatures ϑ _w ; ϑ _k or the required mixing ratio Q _w /Q _k

The pressure in the mixed water area and the total flow can be used to determine the outlet resistance based on an operating point, provided that it is a rigid hydraulic resistance. In this case, the characteristics of the outlet can be described by a constant flow coefficient (Kv value). If there is a flow limiter in the outlet, this can be determined by comparing several operating points (i.e. by operating the sanitary fitting at several operating points).

With the known characteristics of the outlet as well as the inlet pressures and the required mixing ratio, it is possible to calculate the maximum possible flow. Pipe resistances upstream of the sanitary fitting can be neglected as long as they are small compared to the resistances of the sanitary fitting and the outlet. Otherwise, they can be determined or estimated and included in the calculation.

Which sensors are sufficient for determining the maximum flow is explained below.

• • Mischwasserdruck p_m, Mischwasservolumenstrom Q_m sowie Kaltwassertemperatur ϑ_k, Warmwassertemperatur ϑ_w und Mischwassertemperatur ϑ_m sowie jeweils eine Kennlinie des ersten Regelventils K_{v, w} (α_w) (also K_v-Wert des ersten Ventils der Warmwasserleitung in Abhängigkeit von der gewählten Position des Ventils) und des zweiten Regelventils K_{v, k}(αk) (also K_v-Wert des zweiten Ventils der Kaltwasserleitung in Abhängigkeit von der gewählten Position des Ventils) (erste Ausgestaltung); oder
• • Kaltwasserdruck p_k, Warmwasserdruck p_w, Kaltwasservolumenstrom Q_k, Warmwasservolumenstrom Q_w, jeweils eine Kennlinie des ersten Regelventils und des zweiten Regelventil sowie
  • ◯ Kaltwassertemperatur und Warmwassertemperatur (zweite Ausgestaltung) oder
  • ◯ Mischwassertemperatur (dritte Ausgestaltung); oder
• • Kaltwasserdruck, Warmwasserdruck, Mischwasserdruck; sowie
  • ◯ Warmwassertemperatur, Kaltwassertemperatur sowie jeweils eine Kennlinie des ersten Regelventils und des zweiten Regelventils (vierte Ausgestaltung); oder
  • ◯ Mischwassertemperatur sowie jeweils eine Kennlinie des ersten Regelventils und des zweiten Regelventils (fünfte Ausgestaltung); oder
  • ◯ Mischwasservolumenstrom sowie
    • ▪ Mischwassertemperatur sowie jeweils eine Kennlinie des ersten Regelventils und des zweiten Regelventils (sechste Ausgestaltung); oder
    • ▪ Warmwassertemperatur, Kaltwassertemperatur, Mischwassertemperatur (siebte Ausgestaltung); oder
  • ◯ Kaltwasservolumenstrom, Warmwasservolumenstrom; sowie
    • ▪ Kaltwassertemperatur, Warmwassertemperatur (achte Ausgestaltung); oder
    • ▪ Mischwassertemperatur (neunte Ausgestaltung)

messbar und die von den Sensoren übermittelten Messwerte durch die Steuereinrichtung erfassbar und verarbeitbar. Insbesondere ist durch die Steuereinrichtung anhand der von den Sensoren erfassten Messwerte und anhand der bekannten Charakteristik des Auslasswiderstands der maximale Durchfluss für den Betriebspunkt berechenbar.In particular, the minimum number of sensors must meet at least one of the following parameter sets

• • mixed water pressure p _m , mixed water volume flow Q _m as well as cold water temperature ϑ _k , hot water temperature ϑ _w and mixed water temperature ϑ _m as well as a characteristic curve of the first control valve K _{v, w} (α _w ) (i.e. K _v value of the first valve of the hot water pipe depending on the selected position of the valve) and the second control valve K _{v, k} (αk) (i.e. K _v value of the second valve of the cold water pipe depending on the selected position of the valve) (first embodiment); or
• • Cold water pressure p _k , hot water pressure p _w , cold water volume flow Q _k , hot water volume flow Q _w , one characteristic curve each of the first control valve and the second control valve and
  • ◯ Cold water temperature and hot water temperature (second design) or
  • ◯ mixed water temperature (third design); or
• • Cold water pressure, hot water pressure, mixed water pressure; and
  • ◯ Hot water temperature, cold water temperature and a characteristic curve of the first control valve and the second control valve (fourth embodiment); or
  • ◯ Mixed water temperature and a characteristic curve of the first control valve and the second control valve (fifth embodiment); or
  • ◯ Mixed water volume flow and
    • ▪ Mixed water temperature and a characteristic curve of the first control valve and the second control valve (sixth embodiment); or
    • ▪ Hot water temperature, cold water temperature, mixed water temperature (seventh configuration); or
  • ◯ Cold water volume flow, hot water volume flow; and
    • ▪ Cold water temperature, hot water temperature (eighth configuration); or
    • ▪ Mixed water temperature (ninth design)

measurable and the measured values transmitted by the sensors can be recorded and processed by the control device. In particular, the control device can calculate the maximum flow for the operating point based on the measured values recorded by the sensors and the known characteristics of the outlet resistance.

It is particularly evident that at least one (relative) pressure sensor is required for each design of the sanitary fitting. A pressure sensor can be used to measure the pressure present in the respective line, in particular the pressure relative to a pressure in the area surrounding the line.

If the characteristics and positions of the control valves are known, the pressure difference can be calculated from the measured volume flow or vice versa. This makes it possible to save on sensors.

While positions and characteristics of the control valves are not necessarily required, the maximum flow coefficient (fully open control valve) is particularly necessary in any case for calculating the maximum flow.

In step b) of the method, a maximum first mixed water volume flow is calculated, in particular on the basis of the measured values recorded by the sensors and on the basis of the known or calculated characteristics of the outlet resistance as well as on the basis of a characteristic value of the maximally opened first valve K _{V, w, max} .

$$Q_k=K_{V,w}\ast \sqrt{p_k-p_m}$$

$$Q_m=K_{V,aus}\ast \sqrt{p_m}$$

$$Q_m=Q_w+Q_k$$

$${\vartheta }_m=\frac{Q_w\ast {\vartheta }_w+Q_k\ast {\vartheta }_k}{Q_w+Q_k}$$

This calculation of the respective maximum first or second mixed water volume flow is carried out using the following basic equations: $$Q_w=K_{V,w}\ast \sqrt{p_w-p_m}$$

$$Q_k=K_{V,w}\ast \sqrt{p_k-p_m}$$

$$Q_m=K_{V,aus}\ast \sqrt{p_m}$$

$$Q_m=Q_w+Q_k$$

$${\vartheta }_m=\frac{Q_w\ast {\vartheta }_w+Q_k\ast {\vartheta }_k}{Q_w+Q_k}$$

For the sake of simplicity, the influence of density was neglected in the flow equations and in Richmann's mixing formula. The density can be included in the formulas or calculations if required without changing the basic procedure.

The following applies in particular to the maximum first mixed water volume flow: $$\left(\text{V}\right)\Rightarrow Q_k^{\ast }=Q_w\cdot \frac{{\vartheta }_w-{\vartheta }_m}{{\vartheta }_m-{\vartheta }_k}$$

Inserting (II) and (V*) into (IV) yields $$Q_m=K_{V,w,max}\cdot \sqrt{p_w-p_m}\cdot \left(1+\frac{{\vartheta }_w-{\vartheta }_m}{{\vartheta }_m-{\vartheta }_k}\right)$$

Equating (VI) and (III) $$\begin{array}{c}\begin{array}{cc}{K}_{V,w,max}\cdot \sqrt{p_w-p_m}\cdot \left(1+\frac{{\vartheta }_w-{\vartheta }_m}{{\vartheta }_m-{\vartheta }_k}\right)=K_{V,aus}\ast \sqrt{p_m}& \left(\text{VII}\right)\end{array}\\ \begin{array}{cc}\Rightarrow p_m=\frac{{\mathrm{<figure-callout\; id="1"\; label="p\; w"\; filenames="DE102022129751A1\_0016.png"\; state="\{\{state\}\}">p</figure-callout>}}_w}{1+{\left(\frac{K_{V,aus}}{K_{Vw,max}\cdot \left(1+\frac{{\vartheta }_w-{\vartheta }_m}{{\vartheta }_m-{\vartheta }_k}\right)}\right)}^2}& \left(\text{VII*}\right)\end{array}\end{array}$$

Inserting (VII*) into (III) yields $$Q_{m,max,w}=K_{V,aus}\cdot \sqrt{\frac{{\mathrm{<figure-callout\; id="1"\; label="p\; w"\; filenames="DE102022129751A1\_0016.png"\; state="\{\{state\}\}">p</figure-callout>}}_w}{1+{\left(\frac{K_{V,aus}}{K_{V,w,max}\cdot \left(1+\frac{{\vartheta }_w-{\vartheta }_m}{{\vartheta }_m-{\vartheta }_k}\right)}\right)}^2}}$$

In this calculation, formula (I) was not taken into account. It is therefore not guaranteed that the cold water volume flow assumed according to formula (V*) can be provided at all. This could be checked by a test at the end of the calculation. Alternatively, the calculation is carried out directly for both sides separately and the minimum of the two calculated Q _m,max values is used at the end.

In step b) of the method, a maximum second mixed water volume flow is calculated, in particular on the basis of the measured values recorded by the sensors and on the basis of the known or calculated characteristics of the outlet resistance as well as on the basis of a characteristic value of the maximally opened second valve K _{V, k, max} .

The maximum second mixed water volume flow is then particularly $$\left(\text{V}\right)\Rightarrow Q_w^{\ast }=Q_k\cdot \frac{{\vartheta }_k-{\vartheta }_m}{{\vartheta }_m-{\vartheta }_w}$$

Inserting (II) and (V**) into (IV) yields $$Q_m=K_{V,k,max}\cdot \sqrt{p_k-p_m}\cdot \left(1+\frac{{\vartheta }_k-{\vartheta }_m}{{\vartheta }_m-{\vartheta }_w}\right)$$

Equating (VI) and (III) $$\begin{array}{c}\begin{array}{cc}{K}_{V,k,max}\cdot \sqrt{p_k-p_m}\cdot \left(1+\frac{{\vartheta }_k-{\vartheta }_m}{{\vartheta }_m-{\vartheta }_w}\right)=K_{V,aus}\ast \sqrt{p_m}& \left(\text{VII}\right)\end{array}\\ \begin{array}{cc}\Rightarrow p_m=\frac{{\mathrm{<figure-callout\; id="1"\; label="p\; k"\; filenames="DE102022129751A1\_0016.png"\; state="\{\{state\}\}">p</figure-callout>}}_k}{1+{\left(\frac{K_{V,aus}}{K_{Vk,max}\cdot \left(1+\frac{{\vartheta }_k-{\vartheta }_m}{{\vartheta }_m-{\vartheta }_w}\right)}\right)}^2}& \left(\text{VII}**\right)\end{array}\end{array}$$

Inserting (VII**) into (III) yields $$Q_{m,max,k}=K_{V,aus}\cdot \sqrt{\frac{{\mathrm{<figure-callout\; id="1"\; label="p\; k"\; filenames="DE102022129751A1\_0016.png"\; state="\{\{state\}\}">p</figure-callout>}}_k}{1+{\left(\frac{K_{V,aus}}{K_{V,k,max}\cdot \left(1+\frac{{\vartheta }_k-{\vartheta }_m}{{\vartheta }_m-{\vartheta }_w}\right)}\right)}^2}}$$

Formula (II) was not taken into account in this calculation. It is therefore not guaranteed that the hot water volume flow assumed by formula (V**) can be provided at all. This could be checked by a test at the end of the calculation.

Alternatively, the calculation is carried out directly for both sides separately and at the end the minimum of the two calculated Q _{m, max} values is used.

The following applies to the selection of the smaller value, i.e. the minimum of the calculated mixed water volume flows: $$Q_{m,max}=\text{min}\left(Q_{m,max,k};Q_{m,max,w}\right)$$

The calculated maximum flow Q _{m, max} is used in particular to improve the volume flow adjustment and visualization for the user (linear adjustment, correct representation of the potential). For example, by adjusting a relative scale (100% = Q _{m, max} ) or by displaying the maximum value when using an absolute scale (eg: "8 out of 20 l/min").

• • (Relativ-)Drucksensoren im Kaltwasserzulauf, im Warmwasserzulauf und im Mischwasserbereich,
• • Temperatursensoren im Kaltwasserzulauf und im Warmwasserzulauf,
• • wenn zudem die Durchflusscharakteristik der Ventile in Abhängigkeit von der Position bekannt ist.

Sufficient sensor technology is provided, for example, according to the fourth embodiment mentioned above with

• • (Relative) pressure sensors in the cold water inlet, the hot water inlet and the mixed water area,
• • Temperature sensors in the cold water inlet and the hot water inlet,
• • if the flow characteristics of the valves depending on the position are also known.

In this design, the volume flows Q _w , Q _k can be calculated using the pressure differences and the valve positions. Sufficient parameters are known to calculate the maximum flow.

A temperature sensor in the mixed water is not necessarily necessary, for example, because the mixed water temperature can be calculated using Richmann's mixing rule. The sensor can still be helpful in compensating for inaccuracies in the other sensors and the valve characteristic curve

• • (Relativ-)Drucksensoren im Kaltwasserzulauf und im Warmwasserzulauf,
• • Volumenstromsensoren im Kaltwasserzulauf und im Warmwasserzulauf
• • einem Temperatursensor im Mischwasser,
• • wenn zudem die Durchflusscharakteristik der Ventile in Abhängigkeit von der Position bekannt ist.

Sufficient sensor technology is provided, for example, according to the third embodiment mentioned above with

• • (Relative) pressure sensors in the cold water inlet and the hot water inlet,
• • Volume flow sensors in the cold water inlet and the hot water inlet
• • a temperature sensor in the mixed water,
• • if the flow characteristics of the valves depending on the position are also known.

In this design, the mixed water pressure can be calculated using the valve characteristics, the inlet pressures and volume flows Q _w , Q _k and enough parameters are known to calculate the maximum flow rate.

In this example, the temperature sensor in the mixed water is not necessary for characterizing the outlet resistance and calculating the maximum flow. However, it is required for controlling the mixed water temperature.

A sanitary fitting is also proposed, comprising at least a hot water pipe with a first control valve, a cold water pipe with a second control valve and a mixed water pipe connected thereto, which has an outlet with a fixed or variable outlet resistance and a known characteristic. The sanitary fitting also comprises a minimum number of sensors by means of which certain parameters of the sanitary fitting can be measured, as well as a control device for recording and processing the measured values transmitted by the sensors. The control device is designed to carry out the described method and thus to determine the maximum flow rate.

In particular, the control device can calculate a maximum flow rate for an operating point (volume flow and mixed water temperature) of the sanitary fitting selected by a user based on the measured values measured by the sensors and the known characteristics of the outlet resistance.

In particular, the control device is designed to determine the characteristic of the outlet resistance based on at least one set operating point of the sanitary fitting, so that the then determined and thus known characteristic is stored in the control device for the outlet with the fixed or the variable outlet resistance.

In particular, the sanitary fitting comprises at least additionally a (visual) display device for the user, which provides a qualitative representation of a volume flow that can be set by the user as a function of the maximum flow rate.

The sanitary fitting in particular has a fitting housing, which preferably consists at least partially of (cast) metal, such as brass, and/or plastic. The fitting housing can have an outlet that is fixed to the fitting housing in a rigid or movable manner, in particular pivotable and/or at least partially extendable. In addition, the fitting, in particular the fitting housing, has a liquid line that leads in particular to the outlet with an outlet opening for the liquid.

The liquid can be released in particular to the surroundings of the sanitary fitting via the outlet opening. Furthermore, the outlet opening can be formed on the outlet. The liquid line can be formed in the fitting housing, for example, at least partially in the manner of a cavity, a channel and/or a bore. This can also mean in particular that the liquid line is at least partially formed by the fitting housing and/or that the liquid line cannot be a separate component. In addition, the liquid line can be at least partially formed as a hose line. For example, the liquid line can be a mixed water line.

The fitting housing can be fastened in particular to a support, such as a worktop, a washstand, the sink or wash basin. For this purpose, the support can have a mounting opening into which the fitting housing can be inserted with a mounting section and/or to which the fitting housing can be fastened with a fastening element, for example in the manner of a nut.

The electronic fitting (in particular the electronic components of the sanitary fitting) is arranged and/or attached to a wall, in particular outside of the field of vision (for example, beneath a washbasin or worktop or, in the case of a shower fitting, on an opposite side of a shower wall, e.g. in a utility room). Both the operating unit (actuating and display elements) and the outlet openings or the outlet, which must be within the field of vision of a user, can be spatially separated from the electronic fitting and are connected to the electronic fitting by data or fluid lines.

The cold water temperature is in particular a maximum of 25 °C (Celsius), preferably 1 °C to 25 °C, particularly preferably 5 °C to 20 °C and/or the hot water temperature is in particular a maximum of 90 °C, preferably 25 °C to 90 °C, particularly preferably 55 °C to 65 °C.

To operate the sanitary fitting, the sanitary fitting can have at least one actuating element. The at least one actuating element can be, for example, an actuating handle, an actuating button, an actuating puck, a touchscreen and/or a push plate. The at least one actuating element can be used to control the removal of the liquid or a property of the liquid. In particular, the mixed water temperature and/or a withdrawal amount of the liquid (i.e. the operating point of the sanitary fitting) can be adjusted via the at least one actuating element.

The sanitary fitting can in particular be an electronic sanitary fitting in which the valves, the mixed water temperature and/or the withdrawal quantity/volume flow of the liquid can be controlled or operated electronically.

The sensors of the sanitary fitting are connected to the control device in particular via signal lines. In other words, this can also be described as the control device being designed and configured to feed back a controlled variable (for example: volume flow, differential pressure) to the control valves, for example in the form of an electrical signal.

In particular, the sanitary fitting comprises a data processing system, e.g. the control device, the means for carrying out the steps of the method and/or which has means which are suitably equipped, configured or programmed to carry out the steps of the method or which carry out the method.

The means comprise, for example, a processor and a memory in which instructions to be executed by the processor are stored, as well as data lines or transmission devices which enable a transmission of instructions, measured values, data or the like between the mentioned elements of the sanitary fitting.

The “means” may in particular comprise one or more of the following components: controller(s), microcontroller, data storage, data connection, display devices (such as a display), counter or timer, at least one further sensor, an energy source, etc.

A computer program is further proposed, comprising instructions which, when the program is executed by a computer, cause the computer to carry out the described method or the steps of the described method.

A computer-readable storage medium is also proposed, comprising instructions which, when executed by a computer, cause the computer to carry out the described method or the steps of the described method.

The statements relating to the sanitary fitting are particularly applicable to the method, the data processing system and/or the computer-implemented method (i.e. the computer program and the computer-readable storage medium) and vice versa.

The use of indefinite articles ("a", "an", "an" and "another"), particularly in the patent claims and the description reflecting them, is to be understood as such and not as a number. Terms or components introduced accordingly are therefore to be understood as being present at least once and, in particular, can also be present multiple times.

As a precaution, it should be noted that the numerals used here ("first", "second", ...) primarily serve (only) to distinguish between several similar objects, sizes or processes, and in particular do not necessarily specify a dependency and/or sequence of these objects, sizes or processes. If a dependency and/or sequence is required, this is explicitly stated here or it is obvious to the person skilled in the art when studying the specifically described design. If a component can occur multiple times ("at least one"), the description of one of these components can apply equally to all or part of the majority of these components, but this is not mandatory.

• 1: ein erstes Diagramm;
• 2: ein zweites Diagramm;
• 3: eine Auswahl qualitativer Anzeigen für einen Volumenstrom;
• 4: eine quantitative Anzeige eines Volumenstroms;
• 5: ein drittes Diagramm;
• 6: eine Sanitärarmatur
• 7: ein viertes Diagramm; und
• 8: ein fünftes Diagramm.

The invention and the technical environment are explained in more detail below with reference to the attached figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments given. In particular, it should be noted that the figures and in particular the size relationships shown are only schematic. They show:

• 1 : a first diagram;
• 2 : a second diagram;
• 3 : a selection of qualitative indicators for a volume flow;
• 4 : a quantitative indication of a volume flow;
• 5 : a third diagram;
• 6 : a sanitary fitting
• 7 : a fourth diagram; and
• 8th : a fifth diagram.

1 shows a first diagram. 2 show a second diagram. The 1 and 2 are described together below.

The horizontal axis shows a rotation angle 30 of the adjustment for a control element to be operated by a user. The flow rate 15 is shown on the vertical axis.

In conventional sanitary fittings 1, the volume (i.e. the volume flow 16 or the jet hardness) is adjusted by the user changing the flow cross-section in a control valve via an actuating element (shown here as the angle of rotation 30 of the actuating element). As a rule, an outlet resistance (e.g. a shower) is connected downstream of the hydraulic resistance of the sanitary fitting 1. The hydraulic resistance of the sanitary fitting 1 and the outlet resistance together determine the flow 15 of the system. If the resistances are very different, the larger resistance (smaller cross-section) primarily determines the flow 15. This means that in the lower range of the volume adjustment (control valve slightly open) the control valve position determines the flow 15 to a large extent, while in the upper range of the volume adjustment (control valve wide open) the outlet resistance is often the determining factor (see 1 ). This leads to a non-linear volume adjustment.

This effect is even more pronounced if the outlet contains a flow restrictor (flow stabilizer) that changes its flow cross-section depending on the pressure (see 2 ).

The diagrams show the possible flow 15 depending on the position of an actuating element.

3 shows a selection of qualitative displays for an (actually present) volume flow 16. 4 shows a quantitative display of a volume flow 16. The user can be given visual feedback on the volume setting at the user interface. This can be done by a numerical display that shows a qualitative (e.g. values from 1 to 10 or 0 to 100%) or quantitative (e.g. flow in l/min) value. Alternatively, a pictorial representation can be selected.

5 shows a third diagram. The horizontal axis shows a rotation angle 30 of the adjustment for an actuator to be operated by a user. The flow rate 15 is shown on the vertical axis.

It is advantageous to enable a qualitative adjustment (and display) of the volume flow 16 at the sanitary fitting 1 (see 3 ), e.g. in a sanitary fitting 1 for controlling a large shower system. The volume flow 16 should change as linearly as possible when adjusted by the user, i.e. proportionally to the value of the preset. The behavior known from conventional sanitary fittings 1, that the flow 15 (the volume flow 16) or the jet hardness changes greatly in the lower range of the adjustment and hardly at all in the upper range, i.e. not proportionally or linearly (see 1 and 2 ) should be avoided. The maximum value of the volume adjustment (i.e. the actual maximum volume flow 16) should coincide with the maximum or the maximum possible flow 15, so that on the one hand the default value selected by the user cannot be greater than the maximum flow 15 (linearity in the upper adjustment range violated) and on the other hand the maximum possible flow 15 can always be selected.

5 shows this advantageous adjustment. The flow rate 15 changes proportionally or linearly to the angle of rotation 30 of the control element. The increments 31 of the control element 30 that can be selected by the user are always the same size. The adjustment by the maximum angle of rotation 30 produces the maximum flow rate 15 or the maximum volume flow 16.

6 shows a sanitary fitting 1. The sanitary fitting 1 comprises a hot water pipe 2 with a first control valve 3, a cold water pipe 4 with a second control valve 5 and a mixed water pipe 6 connected to it, which has an outlet 7 with a rigid or with a variable outlet resistance (shown here as a rigid outlet resistance) and a known characteristic. The sanitary fitting 1 also comprises a minimum number of sensors 8, 9, 10, by means of which certain parameters of the sanitary fitting 1 can be measured, as well as a control device 11 for recording and processing the measured values 12 transmitted by the sensors 8, 9, 10. The control device 11 can calculate a maximum flow rate 15 for an operating point 13, 14 (mixed water volume flow 18 and mixed water temperature 21) of the sanitary fitting 1 selected by a user based on the measured values 12 measured by the sensors 8, 9, 10 and based on the known characteristic of the outlet resistance.

By determining the possible, i.e. adjustable, maximum flow rate 15, a qualitative adjustment (and representation) of the volume flow rate 16 (actually flowing through the pipes 2, 4, 6) at the sanitary fitting 1 is possible, e.g. in the case of a sanitary fitting 1 for controlling a large shower system. These specifications can only be achieved if the algorithm knows the maximum flow rate 15. However, this depends on many influences, e.g. the inlet pressures 23, 24, the inlet temperatures 19, 20, the selected mixed water temperature 21, the hydraulic resistances of the selected outlets 7.

In known electronic sanitary fittings 1 this possibility to calculate/predict the maximum flow 15 does not exist, thus the stated objectives cannot be achieved.

In the present case, this problem is solved by providing the (electronic) sanitary fitting 1 with a sensor device with which the maximum possible flow rate 15 for the given conditions or for the operating points 13, 14 selected by the user can be calculated or predicted.

• • Eingangsdrücke p_w 24; p_k 23
• • Druck im Mischwasserbereich p_m 17
• • Gesamtdurchfluss bzw. Mischwasservolumenstrom Q_m 18
• • Eingangstemperaturen ϑ_w 20; ϑ_k bzw. das benötigte Mischungsverhältnis Q_w/Q_k; mit Q_w als Warmwasservolumenstrom 26 und Q_k als Kaltwasservolumenstrom 25.

For this purpose, the following variables of the hydraulic system must be recorded by sensors or calculated using known hydraulic relationships:

• • Input pressures p _w 24; p _k 23
• • Pressure in the mixed water area p _m 17
• • Total flow or mixed water volume flow Q _m 18
• • Inlet temperatures ϑ _w 20; ϑ _k or the required mixing ratio Q _w /Q _k ; with Q _w as hot water volume flow 26 and Q _k as cold water volume flow 25.

The outlet resistance can be determined using the mixed water pressure 17 and the mixed water volume flow 18 based on an operating point 13, 14, provided that it is a rigid hydraulic resistance. In this case, the characteristics of the outlet 7 can be described by a constant flow coefficient (Kv value) (see 7 ). If there is a flow restrictor in the outlet 7, this can be done by adjusting several operating points 13, 14 (see 8th ), i.e. by operating the sanitary fitting 1 at several operating points 13, 14.

With the known characteristics of the outlet 7 as well as the inlet pressures 23, 24 and the required mixing ratio, it is possible to calculate the maximum possible flow rate 15. Line resistances upstream of the sanitary fitting 1 can be neglected provided they are small compared to the resistances of the sanitary fitting 1 and the outlet 7. Otherwise, they can be determined or estimated and included in the calculation.

Using the control device 11, a proportional control of a volume flow 16 that can be regulated by the user and flows out via the outlet 7 can be provided for the user of the sanitary fitting 1 based on the known maximum flow 15. Using the control device 11, a maximum volume flow 16 that can be set by the user and flows out via the outlet 7 can be determined based on the known maximum flow 15, which maximum volume flow 16 corresponds to the maximum flow 15.

Here, the temperatures 19, 20, 21 are determined or measured by the first sensors 8, the pressures 23, 24, 17 by the second sensors 9 and the volume flows 25, 26 by the third sensors 10. The control valves 3, 5 have known characteristic curves 22.

• • Mischwasserdruck p_m 17, Mischwasservolumenstrom Q_m 18 sowie Kaltwassertemperatur ϑ_k 19, Warmwassertemperatur ϑ_w 20 und Mischwassertemperatur ϑ_m 21 sowie jeweils eine Kennlinie 22 des ersten Regelventils K_vP1 3 (also K_v-Wert über Position) und des zweiten Regelventil K_vP2 5 (also K_v-Wert über Position) (erste Ausgestaltung); oder
• • Kaltwasserdruck p_k 23, Warmwasserdruck p_w 24, Kaltwasservolumenstrom Q_k 25, Warmwasservolumenstrom Q_w 26, jeweils eine Kennlinie 22 des ersten Regelventils 3 und des zweiten Regelventils 5 sowie
  • ◯ Kaltwassertemperatur 19 und Warmwassertemperatur 20 (zweite Ausgestaltung) oder
  • ◯ Mischwassertemperatur 21 (dritte Ausgestaltung); oder
• • Kaltwasserdruck 23, Warmwasserdruck 24, Mischwasserdruck 17; sowie
  • ◯ Warmwassertemperatur 20, Kaltwassertemperatur 19 sowie jeweils eine Kennlinie 22 des ersten Regelventils 3 und des zweiten Regelventils 5 (vierte Ausgestaltung); oder
  • ◯ Mischwassertemperatur 21 sowie jeweils eine Kennlinie 22 des ersten Regelventils 3 und des zweiten Regelventils 5 (fünfte Ausgestaltung); oder
  • ◯ Mischwasservolumenstrom 18 sowie
    • ▪ Mischwassertemperatur 21 sowie jeweils eine Kennlinie 22 des ersten Regelventils 3 und des zweiten Regelventils 5 (sechste Ausgestaltung); oder
    • ▪ Warmwassertemperatur 20, Kaltwassertemperatur 19, Mischwassertemperatur 21 (siebte Ausgestaltung); oder
  • ◯ Kaltwasservolumenstrom 25, Warmwasservolumenstrom 26; sowie
    • ▪ Kaltwassertemperatur 19, Warmwassertemperatur 20 (achte Ausgestaltung); oder
    • ▪ Mischwassertemperatur 21 (neunte Ausgestaltung)

messbar und die von den Sensoren 8, 9, 10 übermittelten Messwerte 12 sind durch die Steuereinrichtung 11 erfassbar und verarbeitbar. Durch die Steuereinrichtung 11 ist anhand der von den Sensoren 8, 9, 10 erfassten Messwerte 12 und anhand der bekannten Charakteristik des Auslasswiderstands 7 der maximaler Durchfluss 15 für den Betriebspunkt 13, 14 berechenbar. Dieser kann dann für die Betätigung der Sanitärarmatur 1 durch den Nutzer zur qualitativen Darstellung des Volumenstroms 16 verwendet werden. Dem Nutzer kann also z. B. dargestellt werden, dass er in einem bestimmten Betriebspunkt 13, 14 z. B. 40 % des möglichen maximalen Volumenstroms 16 gerade nutzt. Sollte der Nutzer den maximalen Volumenstrom 16 einstellen, wird dieser dem berechneten maximalen Durchfluss 15 entsprechen.Not all of the 6 shown sensors 8, 9, 10 are required to determine the maximum flow 15. Only the minimum number of sensors 8, 9, 10 is required, e.g. with the minimum number of sensors 8, 9, 10 at least one of the following parameter sets is

• • Mixed water pressure p _m 17, mixed water volume flow Q _m 18 and cold water temperature ϑ _k 19, hot water temperature ϑ _w 20 and mixed water temperature ϑ _m 21 as well as a characteristic curve 22 of the first control valve K _vP1 3 (i.e. K _v value over position) and the second control valve K _vP2 5 (i.e. K _v value over position) (first design); or
• • Cold water pressure p _k 23, hot water pressure p _w 24, cold water volume flow Q _k 25, hot water volume flow Q _w 26, one characteristic curve 22 each of the first control valve 3 and the second control valve 5 and
  • ◯ Cold water temperature 19 and hot water temperature 20 (second configuration) or
  • ◯ Mixed water temperature 21 (third design); or
• • Cold water pressure 23, hot water pressure 24, mixed water pressure 17; and
  • ◯ Hot water temperature 20, cold water temperature 19 and a characteristic curve 22 of the first control valve 3 and the second control valve 5 (fourth embodiment); or
  • ◯ Mixed water temperature 21 and a characteristic curve 22 of the first control valve 3 and the second control valve 5 (fifth embodiment); or
  • ◯ Mixed water volume flow 18 and
    • ▪ Mixed water temperature 21 and a characteristic curve 22 of the first control valve 3 and the second control valve 5 (sixth embodiment); or
    • ▪ Hot water temperature 20, cold water temperature 19, mixed water temperature 21 (seventh configuration); or
  • ◯ Cold water volume flow 25, hot water volume flow 26; and
    • ▪ Cold water temperature 19, hot water temperature 20 (eighth configuration); or
    • ▪ Mixed water temperature 21 (ninth design)

measurable and the measured values 12 transmitted by the sensors 8, 9, 10 can be recorded and processed by the control device 11. The control device 11 can calculate the maximum flow rate 15 for the operating point 13, 14 based on the measured values 12 recorded by the sensors 8, 9, 10 and based on the known characteristics of the outlet resistance 7. This can then be used by the user to qualitatively represent the volume flow 16 when operating the sanitary fitting 1. The user can therefore be shown, for example, that at a certain operating point 13, 14 he is currently using, for example, 40% of the possible maximum volume flow 16. If the user sets the maximum volume flow 16, this will correspond to the calculated maximum flow rate 15.

The control device 11 is designed to determine the characteristic of the outlet resistance based on at least one set operating point 13, 14 of the sanitary fitting 1, so that the then determined and thus known characteristic is stored in the control device 11 for the outlet 7 with the fixed or the variable outlet resistance.

The sanitary fitting 1 additionally comprises a (visual) display device 27 for the user, which provides a qualitative representation of a volume flow 16 adjustable by the user as a function of the calculated maximum flow 15.

• • sowie anhand eines Kennwerts des maximal geöffneten ersten Regelventils 3 K_{V, w, max} ein maximaler erster Mischwasservolumenstrom Q_{m, max, w} berechnet wird;
• • sowie anhand eines Kennwerts des maximal geöffneten zweiten Regelventils 5 K_{v, k, max} ein maximaler zweiter Mischwasservolumenstrom Q_{m, max ,k} berechnet wird;

In the method, in step a), the sanitary fitting 1 is operated at an operating point 13, 14 of the sanitary fitting 1. In a step b), a maximum flow rate 15 is calculated for the current operating point 13, 14 by the control device 11 under the assumption that the maximum flow rate 15 is present when one of the control valves 3, 5 (of the first control valve 3 and the second control valve 5) is fully open and the other control valve 5, 3 (of the first control valve 3 and the second control valve 5) has a position required to maintain a target temperature; based on the measured values 12 recorded by the sensors 8, 9, 10 and based on the known or calculated characteristics of the outlet resistance

• • and a maximum first mixed water volume flow Q _{m, max, w} is calculated based on a characteristic value of the maximum open first control valve 3 K _{V, w, max} ;
• • and a maximum second mixed water volume flow Q _{m, max ,k} is calculated based on a characteristic value of the maximum open second control valve 5 K _{v, k, max} ;

In step c), the values of the first mixed water volume flow 18 and the second mixed water volume flow 18 are compared. In step d), the smaller value is selected and this value is used as the maximum flow Q _m,max .

In a step e), the control device 11 uses the known maximum flow rate 15 to provide a user of the sanitary fitting 1 with proportional control of a volume flow rate 16 that can be controlled by a user and flows out via the outlet 7. In step e), the control device 11 uses the known maximum flow rate 15 to determine a maximum volume flow rate 16 that flows out via the outlet 7 for the operating point 13, 14, which corresponds to the maximum flow rate 15.

According to a step i) of the method, the sanitary fitting 1 is operated at at least one operating point 13, 14 of the sanitary fitting 1 and a mixed water volume flow 21 and a mixed water pressure 17 are measured or determined by the sensors 8, 9, 10. In step ii), the characteristic of the outlet resistance is determined on the basis of the measured values 12 measured in step i). In step iii), the characteristic determined in step ii) is stored in the control device 11. Steps i) to iii) can be carried out before steps a) to d) on the sanitary fitting 1 or on a partial sanitary fitting 28 with a line 29 which has the outlet 7 with the rigid or with the variable outlet resistance and the characteristic. The characteristic determined in this way can be stored in the control device 11 of the sanitary fitting 1 which is later used by the user. The partial sanitary fitting 28 can e.g. B. include a reference system on the basis of which the characteristics of the outlet resistance that is later provided in the (actually installed) sanitary fitting 1 are determined.

The liquid flowing through the sanitary fitting 1 is discharged into an environment 32 of the sanitary fitting 1 via the outlet opening or outlet 7.

To operate the sanitary fitting 1, the sanitary fitting 1 can have an actuating element, e.g. one that can be rotated through an angle of rotation 30. The actuating element can be, for example, an actuating handle, an actuating button, an actuating puck and/or a push plate. The withdrawal of the liquid or a property of the liquid can be controlled via the actuating element. The mixed water temperature 21 and/or a withdrawal amount of the liquid, i.e. the mixed water volume flow 18 (i.e. the operating point 13, 14 of the sanitary fitting 1), can be adjusted via the actuating element.

The sensors 8, 9, 10 of the sanitary fitting 1 are connected to the control device 11 via signal lines. The control device 11 is designed and configured to feed back a controlled variable (for example: volume flow 18, 25, 26, differential pressure 17, 23, 24) to the control valves 3, 5, for example in the form of an electrical signal.

7 shows a fourth diagram. 8th shows a fifth diagram. The 7 and 8th are described together below.

The mixed water pressure 17 is plotted on the horizontal axis. The mixed water volume flow 18 is plotted on the vertical axis. The curve shows the eigen ture or characteristic of the outlet 7 depending on these parameters.

By measuring the mixed water pressure 17 and the mixed water volume flow 18, it is possible to determine the outlet resistance using an operating point 13, 14, provided that it is a rigid hydraulic resistance. In this case, the characteristics of the outlet 7 can be described by a constant flow coefficient (Kv value) (see 7 ). If there is a flow restrictor in the outlet 7, this can be done by adjusting several operating points 13, 14 (see 8th ), i.e. by operating the sanitary fitting 1 at several operating points 13, 14.

With the known characteristics of the outlet 7 determined in this way as well as the other required parameters mentioned, it is possible to calculate the maximum possible flow rate 15.

List of reference symbols

1

Sanitary fitting

2

Hot water pipe

3

first control valve

4

Cold water pipe

5

second control valve

6

Combined water pipe

7

Outlet

8th

first sensor

9

second sensor

10

third sensor

11

Control device

12

Measured value

13

first operating point

14

second operating point

15

Flow

16

Volume flow

17

Mixed water pressure

18

Mixed water volume flow

19

Cold water temperature

20

Hot water temperature

21

Mixed water temperature

22

curve

23

Cold water pressure

24

Hot water pressure

25

Cold water volume flow

26

Hot water volume flow

27

Display setup

28

Partial sanitary fitting

29

Line

30

Angle of rotation

31

Increment

32

Vicinity

Claims (10)

Method for operating a sanitary fitting (1), wherein the sanitary fitting (1) comprises at least one hot water pipe (2) with a first control valve (3), a cold water pipe (4) with a second control valve (5) and a mixed water pipe (6) connected thereto, which has an outlet (7) with a fixed or with a variable outlet resistance and a characteristic, further comprising a minimum number of sensors (8, 9, 10) by means of which certain parameters of the sanitary fitting (1) can be measured, and a control device (11) for recording and processing the measured values (12) transmitted by the sensors (8, 9, 10), wherein the method comprises at least the following steps: a) operating the sanitary fitting (1) at an operating point (13, 14) of the sanitary fitting (1); b) Calculating a maximum flow rate (15) for the current operating point (13, 14) by the control device (11) on the assumption that the maximum flow rate (15) is present when one of the control valves (3, 5) is fully open and the other control valve (5, 3) is in a position required to maintain a target temperature; wherein a maximum first mixed water volume flow is calculated based on the measured values (12) recorded by the sensors (8, 9, 10) and based on the known or calculated characteristics of the outlet resistance • and based on a characteristic value of the maximally opened first control valve (3); • and based on a characteristic value of the maximally opened second control valve (5) a maximum second mixed water volume flow is calculated; c) Comparing the values of the first mixed water volume flow and the second mixed water volume flow; d) Selecting the smaller value and using this value as the maximum flow rate (15). Procedure according to Claim 1 , wherein in a step e) the control device (11) is used on the basis of the known maximum flow rate (15) for a user of the sanitary fitting (1) to carry out a proportional control of a user-adjustable and the volume flow (16) flowing out via the outlet (7) is provided. Method according to one of the preceding Claims 1 and 2 , wherein in step e) the control device (11) uses the known maximum flow rate (15) to determine a maximum volume flow rate (16) flowing out via the outlet (7) for the operating point (13, 14), which corresponds to the maximum flow rate (15). Method according to one of the preceding Claims 1 until 3 , at least comprising the following steps: i) operating the sanitary fitting (1) at at least one operating point (13, 14) of the sanitary fitting (1) and measuring or determining a mixed water volume flow (18) and a mixed water pressure (17) by means of the sensors (8, 9, 10); ii) determining the characteristic of the outlet resistance on the basis of the measured values (12) measured in step i); iii) storing the characteristic in the control device (11); wherein steps i) to iii) are carried out before steps a) to d) on the sanitary fitting (1) or on a partial sanitary fitting (28) with a line (29) which has the outlet (7) with the rigid or with the variable outlet resistance and the characteristic, wherein the characteristic thus determined is stored in the control device (11) of the sanitary fitting (1). Sanitary fitting (1), comprising at least a hot water line (2) with a first control valve (3), a cold water line (4) with a second control valve (5) and a mixed water line (6) connected thereto, which has an outlet (7) with a fixed or with a variable outlet resistance and a known characteristic; further comprising a minimum number of sensors (8, 9, 10) by means of which certain parameters of the sanitary fitting (1) can be measured, and a control device (11) for detecting and processing the measured values (12) transmitted by the sensors (8, 9, 10); wherein the control device (11) is designed to carry out the method according to one of the preceding claims and thus to determine the maximum flow rate (15). Sanitary fitting (1) after Claim 5 , wherein the control device (11) can provide the user of the sanitary fitting (1) with proportional control of a volume flow (16) which can be controlled by the user and flows out via the outlet (7) on the basis of the known maximum flow rate (15). Sanitary fitting (1) according to one of the preceding Claims 5 and 6 , wherein the control device (11) can be used to determine, on the basis of the known maximum flow rate (15), a maximum volume flow rate (16) which can be set by the user and flows out via the outlet (7) and which corresponds to the maximum flow rate (15). Sanitary fitting (1) according to one of the preceding Claims 5 until 7 , wherein the minimum number of sensors (8, 9, 10) is used to measure at least one of the following parameter sets • mixed water pressure (17), mixed water volume flow (18) and cold water temperature (19), hot water temperature (20) and mixed water temperature (21) and also a characteristic curve (22) of the first control valve (3) and the second control valve (5); or • cold water pressure (23), hot water pressure (24), cold water volume flow (25), hot water volume flow (26), a characteristic curve (22) of the first control valve (3) and the second control valve (5) and ◯ cold water temperature (19) and hot water temperature (20) or ◯ mixed water temperature (21); or • cold water pressure (23), hot water pressure (24), mixed water pressure (17); and ◯ hot water temperature (20), cold water temperature (19) and a characteristic curve (22) of the first control valve (3) and the second control valve (5); or ◯ mixed water temperature (21) and a characteristic curve (22) of the first control valve (3) and the second control valve (5); or ◯ mixed water volume flow (18) and ▪ mixed water temperature (21) and a characteristic curve (22) of the first control valve (3) and the second control valve (5); or ▪ hot water temperature (20), cold water temperature (19), mixed water temperature (21); or ◯ cold water volume flow (25), hot water volume flow (26); and ▪ cold water temperature (19), hot water temperature (20); or ▪ mixed water temperature (21) can be measured and the measured values (12) transmitted by the sensors (8, 9, 10) can be recorded and processed by the control device (11); wherein the maximum flow rate (15) for the operating point (13, 14) can be calculated by the control device (11) on the basis of the measured values (11) recorded by the sensors (8, 9, 10) and on the basis of the known characteristics of the outlet resistance. Sanitary fitting (1) according to one of the preceding Claims 5 until 8th , wherein the control device (11) is designed to determine the characteristic of the outlet resistance based on at least one set operating point (13, 14) of the sanitary fitting. so that the then determined and thus known characteristic is stored in the control device (11) for the outlet (7) with the fixed or the variable outlet resistance. Sanitary fitting (1) according to one of the preceding Claims 5 until 9 , at least additionally comprising a display device (27) for the user, which provides a qualitative representation of a volume flow (16) adjustable by the user as a function of the maximum flow rate (15).

Images