WO2018095732A1

WO2018095732A1 - Domestic appliance and method for the domestic appliance with an automatic material detection process

Info

Publication number: WO2018095732A1
Application number: PCT/EP2017/078606
Authority: WO
Inventors: Alvaro Harbach; Philipp Neumaier
Original assignee: BSH Hausgeräte GmbH
Priority date: 2016-11-23
Filing date: 2017-11-08
Publication date: 2018-05-31
Also published as: PL3545126T3; CN110023557B; EP3545126B1; EP3545126A1; CN110023557A; DE102016223080A1

Abstract

The invention relates to a domestic appliance (10) for drying objects (20) to be dried which can be arranged in the domestic appliance (10) in a regulated manner. The domestic appliance (10) has the following: a container (14) for receiving the objects (20) to be dried and at least one air line (36) which is fluidically connected to the container (14), wherein an airflow (30) flows through the air line (36) and through the container (14), and at least one sensor (32) is arranged in the airflow (30) in order to detect at least two physical variables selected from the group consisting of an absolute water load x, an air temperature T, an air pressure, or another physical variable which is connected to the regulated drying process. The at least one sensor (32) is connected to an analysis unit (24, 24') which is configured to receive and analyze the at least two physical variables from the at least one sensor (32) and transmit the physical variables and/or the analyzed physical variables to a control unit (22) in order to carry out the drying process in a regulated manner. The invention additionally relates to a method for drying objects (20) in a domestic appliance (10) in a regulated manner.

Description

HOUSEHOLD UNIT AND METHOD FOR THE HOME APPLIANCE WITH

AUTOMATIC MATERIAL RECOGNITION

The present invention relates to a household appliance for the controlled performance of a drying of objects to be dried in the domestic appliance and a method for the controlled performance of a drying of objects to be dried which can be arranged in a domestic appliance, in particular textiles in a laundry care appliance.

Usually, objects arranged in a household appliance are first cleaned and then dried in the same household appliance or in another domestic appliance. The objects to be dried may have different drying properties, in which the articles dry optimally. Articles to be dried may be placed in a laundry care device such as a dryer or a washer-dryer or in a dishwasher. In the case of a laundry care appliance, the items to be dried are textiles to be dried, while in the case of a dishwasher, the items to be dried are kitchen utensils to be dried such as dishes, potters, kitchen gadgets, etc. On the one hand, drying as such does not always produce the desired effect of obtaining fully dried articles or, on the other hand, the effect of drying the articles too long or drying them under conditions which destroy the articles over the long term. In particular, textiles can be damaged in dryers.

In view of these problems in the prior art, the object of the present invention is to provide a household appliance and a method for operating a household appliance, in which objects disposed therein are recognized and dried according to the detection of the articles under improved conditions. These objects are achieved with a household appliance and a method according to respective independent claim. Further advantages and preferred, optional features of the present invention will become apparent from the dependent claims, the following description and the accompanying drawings. Preferred implementations of the domestic appliance here correspond to preferred embodiments of the method and vice versa, and even if this is not explicitly stated herein.

According to the invention, the domestic appliance for regulating a drying of objects to be dried arranged in the domestic appliance comprises a container for receiving the objects to be dried and at least one air line in fluid communication with the container. An air flow flows through the air line and through the container. The container is z. B. in the case of a laundry care device, the laundry drum, in a dishwasher, the room in which the dishes are arranged and rinsed. The household appliance has at least one sensor for detecting at least two physical variables. The detected physical quantity is selected from the group consisting of the absolute water load x, the air temperature T, an air pressure or other physical quantity which has a dependency on the controlled performance of the drying. Furthermore, the at least one sensor is arranged in the air flow, wherein the at least one sensor is in communication with an evaluation unit which is configured to receive and evaluate the at least two physical quantities of the at least one sensor. Furthermore, the evaluation unit is configured to transmit the physical quantities and / or the evaluated physical quantities to a control unit for the controlled performance of the drying.

In the present case, a domestic appliance is to be understood as meaning a dryer, for example a heat pump or a condensation dryer, a washer-dryer or another air-conducting domestic appliance such as, for example, a dishwasher. The at least one sensor is configured to detect the at least two physical quantities at the same time, in particular to detect physical variables such as an absolute water load x, an air temperature T, an air pressure or the like at the same time, and / or the at least one sensor is configured at least two physical To detect quantities one behind the other. For example, the objects to be dried are textiles, in particular of cotton and / or of synthetic and / or wool and / or a mixture of the aforementioned. In particular, the textile type can be detected with the method according to the invention. Alternatively, the articles to be dried may be various kitchen utensils, especially porcelain, tableware, pots, kitchen gadgets or the like, or a mixture of the foregoing. One advantage of the proposed household appliance is that the objects to be dried or their type or their material, in particular the type of textile, are recognized by the domestic appliance and then dried under conditions adapted to the objects to be dried. As a result, on the one hand, the articles to be dried can be dried satisfactorily and under conditions which less damage the articles.

According to a preferred embodiment, the evaluation unit is arranged outside of the household appliance, in particular in a cloud, wirelessly connected or connectable to a control unit or the evaluation unit is integrated in the household appliance in a control unit or connected thereto. Furthermore, the control unit is configured to control the drying on the basis of the evaluated physical quantities, wherein a memory for storing the physical quantities and / or the evaluated physical quantities is provided. The memory may be integrated in the household appliance. Alternatively, a memory may be provided in the cloud. In particular, the actual course of the drying is displayed on a screen integrated in or on the household appliance or external. For example, the drying history may be displayed on a mobile device or the like, thereby realizing remote monitoring of the drying. Preset setpoints for various objects to be dried are also stored in the memory. For example, a predetermined target temperature and / or a desired air pressure and / or a desired air flow are stored for a cotton article to be dried. The desired values, which are for example assigned to an article made of cotton, are preferably grouped together in one group, in this case for example the "cotton group." Desired values, which are assigned to another object to be dried, are assigned according to another group the currently detected and evaluated physical quantities are compared with the setpoints of the different groups stored in the memory and the conditions after recognition of the assignment a particular group, in particular with respect to the temperature and / or the air flow and / or the air pressure to the recognized objects to be dried. This has the advantage that the household appliance is designed to first identify the articles to be dried or their type and to learn a drying-learning curve each time a drying operation is carried out.

Preferably, the at least one sensor is a miniaturized sensor, in particular a MEMS chip (microelectromechanical system). A MEMS chip advantageously combines mechanical and electrical detection properties. In particular, at least one PTH chip (pressure-temperature-humidity chip) is used to detect the physical quantities. With a PTH chip, the air pressure, the temperature and the humidity can be detected. The PTH chip preferably combines three individual sensors, namely a temperature sensor, a pressure sensor and a humidity sensor, in a single sensor chip. This has the advantage that different physical variables can be determined with one sensor.

According to a preferred embodiment, the evaluation unit is configured to determine thermodynamic variables from the plurality of physical quantities, in particular the specific enthalpy and / or the relative air humidity or the like, and is configured to associate the thermodynamic quantities of a predetermined type of objects to be dried. In the evaluation unit various models are stored, which are used to evaluate the detected physical quantities. Preferably, linear functions, power functions or logarithms or exponential functions or more complex, in particular composite, functions are stored with which the detected physical quantities for determining the thermodynamic variables in the evaluation unit are evaluated. For example, monomials and polynomials are stored which have an integer power high 2, 3, 4... N, where n is an integer and / or polynomials of the type ± 1 / n, where n is an integer. This has the advantage that the drying properties and thus the thermodynamic variables are evaluated according to a model formed according to reality.

The at least one sensor is preferably arranged at a transition between the air line and the container, in particular at a container inlet or a container outlet, or the at least one sensor is arranged in the air line. This has the Advantage that the sensor (s) are exposed to the circulating air flow for measuring the physical quantities. This will better capture the current conditions. With time-dependent detection of the physical quantities, the at least one sensor detects a time-dependent change of the physical quantities. The container is in particular a reserve drum of a tumble dryer or washer-dryer, in particular the at least one sensor is arranged in or on the drum.

Preferably, a sensor or at least two sensors are arranged after a heat sink and / or in front of a heat source for the process air flow. In particular, a sensor is arranged on the drum inlet and / or on the drum outlet. When arranging a first sensor after the heat sink and when placing a second sensor in front of a heat source or at the drum inlet and at the drum outlet, the same physical quantity can be detected simultaneously at two different locations in the air flow. With only one sensor, the same physical quantity can be detected at two consecutive times. This has the advantage that various temporary stationary thermodynamic, in particular atmospheric, conditions of the physical quantities can be recorded simultaneously at different points or successively at one point and subsequently evaluated. In this way it can be determined with a higher degree of accuracy as to which object to be dried is concerned. In a laundry care appliance, such as a tumble dryer or a washer-dryer, the items to be dried are textiles. By capturing the physical quantities, it is predicted what kind of textiles to be dried are. By the term "type of textiles to be dried" is meant the textile itself, for example a textile of cotton, of synthetic, of wool, or of a mixture of textiles.

According to a further preferred embodiment, a first sensor is arranged at one location and a second sensor for detecting at least one physical variable at a second location. The values of the physical variable detected by the first and the second sensor are used by the evaluation unit to calculate the difference between the detected physical quantity of the first sensor and the detected physical quantity of the second sensor. For example, in difference formation, an air pressure difference is determined according to P (t0) = p1 (t0) -p2 (t0), where p1 (t0) is the air pressure in the air flow at the position of the first sensor and p2 (t0) the air pressure in the air ström is at the position of the second sensor at the time tO. Furthermore, the air pressure difference can be determined at two different times, namely at the time t0 and at a later time t1. The difference is then calculated according to P (t1 -t0) = p (t1) -p (t0). The difference can be made with each detected physical quantity, for example with the air temperature T (t), the absolute water load x (t) or the like, where t is the time.

Another aspect of the present invention relates to a method of properly performing a drying of articles in a home appliance. The method comprises the following steps: picking up the objects to be dried into a container of the household appliance, wherein at least one air line is in fluid communication with the container and an air flow flows through the air line and through the container. Furthermore, the method comprises detecting at least two physical quantities selected from the group consisting of an absolute water load x, an air temperature T, an air pressure p or another physical variable which has a dependency on the controlled performance of the drying of at least one sensor arranged in the airflow. Furthermore, the method comprises a transfer of the detected physical quantities to an evaluation unit which is configured to receive and evaluate the at least two physical quantities from the at least one sensor and the at least two physical quantities and the evaluated at least two physical quantities to a control unit for controlled Perform the drying to convey. The at least one sensor used for the method can detect a plurality of physical quantities, preferably at the same time and / or in chronological succession, in particular physical variables such as an absolute water load x, a temperature T, a pressure or the like. These physical quantities have a dependence on the household appliance and the objects to be dried arranged in the domestic appliance. In other words, the detected physical quantities are characteristic of the system consisting of the household appliance and the objects to be dried arranged therein. This has the advantage that by means of the proposed method, the objects arranged in the household appliance are recognized and can be dried gently after recognition under conditions which are stored in the evaluation unit and are assigned to the objects currently arranged in the household appliance. The control unit controls the drying on the basis of the evaluated physical quantities, in particular the control unit controls a container rotation, a reversing, a temperature or the like. The controller controls a setting of the temporary stationary thermodynamic conditions such that the objects to be dried are dried under optimum conditions. This has the advantage that the objects to be dried are dried under mild conditions.

The evaluation unit determines thermodynamic variables from a plurality of physical quantities, in particular the specific enthalpy and / or the relative humidity or the like, and assigns the thermodynamic quantities of a predetermined type of objects to be dried. The determined thermodynamic quantities are stored in a memory, in particular assigned to a group and stored in the assigned group.

The thermodynamic variables are preferably determined on the basis of at least one prediction model stored in the evaluation unit, in particular on the basis of a factory-set multivariant analysis with a partial least squares (PLS) prediction method. Preferably, several prediction models are stored in the evaluation unit, in which the thermodynamic variables are mapped by means of linear functions or power functions or logarithms or exponential functions or more complex, in particular composite, functions. For example, the prediction models comprise monomials and polynomials which have an integer power of high 2, 3, 4 ... n, where n is an integer, and / or polynomials of the type ± 1 / n, where n is an integer. In this way, with the aid of a multivariant analysis with a PLS prediction method, the current thermodynamic conditions in the household appliance can be optimally mapped in the best possible way.

Each evaluated physical variable, in particular each specific thermodynamic variable, is preferably compared with different desired values predetermined in the evaluation unit, each setpoint being assigned to a specific group, wherein in particular for detecting the objects to be dried, each group comprises predetermined setpoint values at the factory. The predetermined setpoint values of a group are each assigned to a type of objects to be dried; in particular, a first group is assigned to a textile type, for example wool, while a second group is assigned another textile type, such as synthetic, is assigned. Preferably, different groups are provided, such as a wool group, a cotton group, a synthetic group, a mixing group or the like. For example, the Wool group includes low temperature and increased airflow targets, while the Cotton group has lower airflow and higher temperature. By comparing the determined thermodynamic quantities with the setpoint values stored in the evaluation unit at the factory, an assignment of the objects to be dried to at least one group is possible, whereby the objects to be dried, in particular automatically, are recognized during the drying process. The setpoint values set at the factory include setpoint values for the physical quantities to be detected and / or for the thermodynamic variables to be determined.

According to a preferred embodiment, a first sensor and at a second location a second sensor for detecting at least one physical quantity are arranged at one point. The evaluation unit forms the difference between the detected physical quantity of the first sensor and the detected physical quantity of the wide sensor. For example, in subtraction, an air pressure difference becomes P (t0) = p1 (t0) -p2 (t0), where p1 (t0) is the air pressure in the airflow at the position of the first sensor and p2 (t0) is the air pressure in the airflow is the position of the second sensor at the time t0. Furthermore, the air pressure difference can be determined at two different times, namely at the time t0 and at a later time t1. The difference is then calculated according to P (t1 -t0) = p (t1) -p (t0). The difference can be made with each detected physical quantity, for example with the air temperature T (t), the absolute water load x (t) or the like, where t is the time.

Preferably, various models are stored in the evaluation unit, which are used to evaluate the detected physical quantities, preferably linear functions or power functions or logarithms or exponential or more complex, especially composite, functions are used with which after detecting the detected physical quantities, the thermodynamic quantities in the evaluation unit are evaluated. This has the advantage that the objects to be dried can be reliably detected in real time. The proposed domestic appliance and the associated method for the controlled carrying out of a drying of objects which can be arranged in the domestic appliance advantageously prevent the destruction of the objects to be dried and at the same time ensure a good drying result by means of the real-time recognition of the thermodynamic variables detected.

Further advantages and features of the present invention will become apparent from the following description of preferred embodiments with reference to the figures of the accompanying drawings. It is understood that individual embodiments shown in the respective figures can have features which can also be used in other embodiments, even if this is not explicitly mentioned, and unless this has been explicitly excluded due to technical circumstances. 1 shows a schematically illustrated domestic appliance, in particular a dryer,

2 shows a schematically illustrated arrangement of sensors in an air flow in a domestic appliance according to FIG. 1, and FIG. 3 shows physical quantities recorded in a flow of air according to FIG.

In the following, the present invention will be explained with reference to a household appliance 10 in the form of a laundry care device in conjunction of FIGS. 1 to 3. The following description of the image is analogously transferable to another air-conducting domestic appliance, such as a dishwasher.

Fig. 1 shows a household appliance 10, in particular a laundry care device with a screen 12 and a container 14. In the container 14 to be dried objects 20, in particular textiles of various kinds, are arranged. The domestic appliance 10 can be started either via the screen 12 or by a mobile device 16 via a wireless data transmission 18, ie a method carried out by the domestic appliance 10 for the controlled performance of a drying of the appliance in the domestic appliance. ordered objects to be dried can be started. The course of the drying may be displayed on the screen 12 and / or the mobile device 16. According to FIG. 1, the container 14 is designed as a laundry drum, which is controlled by a control unit 22. The control unit 22 can be connected to an evaluation unit 24, 24 '. The evaluation unit 24 'can be arranged in the household appliance 10 or the evaluation unit 24 can be comprised outside the household appliance in a cloud 26. In the evaluation unit 24, 24 'different prediction models are stored, with which predictions about the type of concrete to be dried objects 20 are made. In a memory 25, 25 'setpoints are stored in groups 40, each group is assigned 40 predetermined objects to be dried. In particular, each group 40 is associated with a type of textile such as cotton or wool or synthetic or a blend of different textiles.

As shown schematically in FIG. 2, sensors 32 for detecting at least one physical quantity, such as an air temperature T, an air pressure p, an absolute water load x, are arranged in the air flow 30 at various locations. From the detected physical quantities, thermodynamic variables, such as the specific enthalpy h and / or the relative air humidity φ, are determined by means of the evaluation unit 24, 24 '. As shown in FIG. 2, a sensor 32 is arranged on a container outlet 34 and another sensor 32 in the middle of an air line 36. Furthermore, a sensor 32 is arranged downstream of a lint filter 37 and in front of a fan 38. FIG. 2 shows possible locations in the airflow 30 at which a sensor 32 can be positioned to detect physical quantities, in particular an absolute water load x, an air temperature T, an air pressure p or some other physical quantity which is dependent on the having carried out the controlled drying. The at least one sensor 32 is connected to the evaluation unit 24, 24 '. The at least one sensor 32 transmits the detected physical quantities to the evaluation unit 24, 24, which then calculates thermodynamic variables, in particular the specific enthalpy h and / or the relative air humidity φ, based on the various prediction models, and then calculates them in one of the evaluation unit 24 , 24 associated memory 25, 25 'stored setpoints of different groups 40 compares. After a best possible agreement of the calculated thermodynamic variables with the desired values of a group 40 has been determined, which corresponds to a recognition of the objects 20 to be dried, the evaluation unit 24, 24 'transmits the thermodynamic Mixed optimized conditions for performing the drying of the objects to be dried 20 to the control unit 22. The control unit 22 controls the container 14 and the fan 38 in accordance to set the optimal conditions for drying in the household appliance 10. The control of the fan 38, the air flow 30 is adjustable, while the rotational speed of the container 14 is adjustable via the control of the container 14, in particular the drum. In the container 14 driving elements 42 are arranged to support a circulation of arranged in the household appliance 10 textiles.

3 schematically shows the physical variables T, p, x detected by the sensors 32 or the at least one sensor 32 and the thermodynamic variables h, φ calculated therefrom for two different articles 20 to be dried, for example wool and synthetic material. For example, the detected physical quantities T, p, x and the thermodynamic quantities h, φ calculated therefrom on the basis of a first sensor 32 at an inlet of the container 14, preferably a drum inlet, and a second sensor 32 at an outlet of the container 14, were preferred a drum exit, recorded. The physical quantities T, x acquired over time and the thermodynamic quantities h, φ calculated therefrom are plotted against time. The setpoint values stored in the memory 25, 25 'associated with the evaluation unit 24, 24' can also be stored in the form of setpoint curves. In this case setpoint curves are compared with currently detected curves of the thermodynamic quantities h, φ and / or the detected physical quantities T, p, x. At each position of a sensor 32 results in a time course of the physical quantities T, p, x and the thermodynamic quantities h, φ, wherein the shape, the slope or the like are different. The different courses of the detected and / or calculated curves have a dependence on the textual light, the type of textile and / or the weaving. As a result, the type of textile of the objects 20 located in the household appliance can be determined. In particular, by assigning the detected curves or the detected values to a group 40, the articles 20 to be dried arranged in the household appliance 10 are recognized. On the basis of an initial detection of the load mass of the objects to be dried, it is possible to select a suitable prediction model from the stored set of prediction models, so that the recognition can be carried out more accurately. LIST OF REFERENCE NUMBERS

10 home appliance

12 screen

14 containers

16 mobile device

18 wireless data transmission

20 items to be dried

22 control

24, 24 'evaluation unit

25, 25 'memory

26 Cloud

30 airflow

32 sensor

34 container outlet

36 air line

37 lint filter

38 fans

40 group

42 entrainment element

η, φ thermodynamic quantities

T, p, x physical quantities

T air temperature

P air pressure

X absolute water load

h specific enthalpy

Φ relative humidity

Claims

Household appliance (10) for the controlled performance of drying of objects (20) which can be arranged in the domestic appliance (10), the domestic appliance (10) comprising:

a container (14) for receiving the articles (20) to be dried, at least one air line (36) in fluid communication with the container (14), an air stream (30) passing through the air line (36) and through the container (14) flows,

characterized in that

at least one sensor (32) for detecting at least two physical quantities selected from the group consisting of an absolute water load x, an air temperature T, an air pressure and / or another physical variable which has a dependency on the controlled execution of the drying, in Air flow (30) is arranged, wherein the at least one sensor (32) with an evaluation unit (24, 24 ') is in communication, which is configured to receive the at least two physical quantities of the at least one sensor (32) and to communicate the physical quantities and / or the evaluated physical quantities to a control unit (22) for the controlled performance of the drying.

Domestic appliance (10) according to claim 1, wherein the evaluation unit (24) outside the household appliance (10), in particular in a cloud (26) is arranged, with a control unit (22) wirelessly connected or connectable or the evaluation unit (24 ') in the home appliance (10) is integrated in or connected to a control unit (22), wherein the control unit (22) is configured to control the drying on the basis of the evaluated physical quantities, wherein a memory (25, 25 ') for storing the physical quantities and / or the evaluated physical quantities is provided.

3. Household appliance (10) according to one of the preceding claims, wherein the at least one sensor (32) is a miniaturized sensor, in particular a MEMS chip (microelectromechanical system).

4. Household appliance (10) according to one of the preceding claims, wherein the evaluation unit (24, 24 ') is configured to determine thermodynamic variables from the plurality of physical quantities, in particular the specific enthalpy and / or the relative humidity or the like, and configured to associate the thermodynamic quantities of a predetermined type of articles (20) to be dried.

5. Household appliance (10) according to one of the preceding claims, wherein the at least one sensor (32) at a transition between the air line (36) and the container (14) is arranged, in particular at a container inlet or a container outlet (34), or are arranged in the air line (36).

6. Household appliance (10) according to one of the preceding claims, wherein a sensor (32) after a heat sink and / or in front of a heat source for the air flow (30) is / are arranged.

7. Household appliance (10) according to one of the preceding claims, wherein at one point a first sensor (32) and at a second location a second sensor (32) for detecting at least one physical quantity are arranged and that of the first and the second sensor (32) are used by the evaluation unit (24, 24 ') to calculate the difference between the detected physical quantity of the first sensor (32) and the detected physical quantity of the wide sensor (32).

A method of properly controlling a drying of articles (20) in a household appliance (10), the method comprising the steps of:

Drying of the objects to be dried (20) in a container (14) of the household appliance (10), wherein at least one air line (36) with the container (14) in fluid communication and an air flow (30) through the air line (36) and through the container (14) flows, characterized in that

at least two physical quantities selected from the group consisting of an absolute water load x, an air temperature T, and an air pressure, or another physical quantity which is dependent on the controlled performance of the drying, of at least one in the air stream (30) arranged sensor (32) are detected, and

to an evaluation unit (24, 24 ') which is configured to receive and evaluate the at least two physical quantities from the at least one sensor (32) and to send the at least two physical quantities and the evaluated at least two physical quantities to a control unit ( 22) for the controlled performance of drying.

The method of claim 8, wherein the control unit (22) controls the drying on the basis of the evaluated physical quantities, in particular a container rotation, reversing, a temperature or the like controls.

The method of claim 8 or 9, wherein the evaluation unit (24, 24 ') determined from a plurality of physical quantities thermodynamic variables, in particular the specific enthalpy and / or the relative humidity or the like, and the thermodynamic quantities of a predetermined type of objects to be dried (20).

Method according to claim 10, wherein the thermodynamic quantities are determined on the basis of a predictive model stored in the evaluation unit (24, 24 '), in particular on the basis of a factory-set multivariant analysis with a partial least squares (PLS) prediction method.

Method according to one of claims 8 to 1 1, wherein each evaluated physical quantity, in particular each specific thermodynamic quantity, is compared with predetermined in the evaluation unit (24,24 ') different setpoints, each setpoint is associated with a particular group (40), wherein, in particular for the detection of the objects to be dried (20), each group (40) comprises factory predetermined setpoint values. A method according to claim 12, wherein the predetermined set values of a group (40) are associated with a type of articles (20) to be dried, in particular a first group (40) is associated with a textile type, for example wool, while a second group (40) is associated with one other textile type, such as synthetic, is assigned.

Method according to one of claims 8 to 14, wherein at one point a first sensor (32) and at a second location a second sensor (32) for detecting at least one physical quantity are arranged and from the evaluation unit (24, 24 ') the difference between the detected physical quantity of the first sensor (32) and the detected physical quantity of the second sensor (32).

Method according to one of claims 8 to 14, wherein in the evaluation unit (24, 24 ') deposited various models which are used to evaluate the detected physical quantities, preferably power functions or logarithms or exponential functions or more complex, in particular composite, functions are used which, after detection of the detected physical quantities, the thermodynamic variables in the evaluation unit (24, 24 ') are evaluated.