EP3545126B1 - Household apparatus and method for said household apparatus with automatic material recognition - Google Patents

Description

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

Objects arranged in a household appliance are usually first cleaned and then dried in the same household appliance or in a different household appliance. The objects to be dried can have different drying properties with which the objects dry optimally. Objects to be dried can be arranged in a laundry care device, such as a dryer or a washer dryer, or in a dishwasher. In the case of a laundry care device, 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 such as dishes, pots, kitchen utensils, etc.

Drying as such does not always lead, on the one hand, to the desired effect of obtaining completely dried objects, or, on the other hand, to the effect that the objects are exposed to drying for too long or are dried under conditions which destroy the objects over the long term. Textiles in particular can be damaged in dryers.

WO 2014/085329 A1 discloses an energy-efficient dryer system which, by means of a heat exchanger and a heat pump, absorbs thermal energy from the exhaust air and transfers this thermal energy to the air inlet of the tumble dryer. The air duct is designed in such a way that the air at the inlet is heated directly or indirectly by the heat exchanger before the inflowing air is further heated directly or indirectly by the condenser.

WO 2014/198608 A1 discloses an analysis device which is used for analyzing laundry items outside of the laundry treatment device. The analysis device has at least one camera and an evaluation device, with which properties relevant to laundry care can be determined. An image of the item of laundry is recorded with the aid of the camera, and a washing-relevant property is determined with the aid of the analysis device in order to then apply it to a household appliance.

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 arranged therein are recognized and, in accordance with the detection of the objects, are dried under improved conditions.

These objects are achieved with a household appliance and a method according to the respective independent patent claim. Further advantages and preferred, optional features of the present invention emerge from the dependent patent claims, the following description and the accompanying drawing. Preferred versions of the household appliance correspond to preferred versions of the method and vice versa, even if this is not explicitly referred to herein.

According to the invention, the household appliance for the controlled drying of objects to be dried that can be arranged in the household appliance comprises a container for receiving the objects to be dried and at least one air line in fluid connection with the container. A stream of air flows through the air line and through the container. The container is e.g. B. in the case of a laundry care device the laundry drum, in a dishwasher the room in which the dishes are arranged and washed. The household appliance has at least one sensor for detecting at least two physical quantities. The detected physical variable is selected from the group consisting of the absolute water loading x, the air temperature T, an air pressure or another physical variable which is dependent on the controlled performance of the drying.

Furthermore, the at least one sensor is arranged in the air flow, the at least one sensor being connected to an evaluation unit which is configured to receive and evaluate the at least two physical quantities from 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 implementation of the drying.

In the present case, a household appliance is to be understood as a dryer such as, for example, a heat pump or a condensation dryer, a washer-dryer or another air-conducting household appliance such as a dishwasher. The at least one sensor is configured to detect the at least two physical variables 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 to detect the at least two physical Detect quantities one after the other. For example, the objects to be dried are textiles, in particular made of cotton and / or synthetic and / or wool and / or a mixture of the aforementioned. In particular, the type of textile can be recognized with the method according to the invention. Alternatively, the objects to be dried can be various kitchen utensils, in particular porcelain, dishes, pots, kitchen utensils or the like, or a mixture of the aforementioned. 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 household appliance and are then dried under conditions adapted to the objects to be dried. As a result, the objects to be dried can on the one hand be dried satisfactorily and under conditions that are less damaging to the objects.

According to a preferred embodiment, the evaluation unit is arranged outside the household appliance, in particular in a cloud, wirelessly connected or connectable to a control unit, or the evaluation unit is integrated in or connected to a control unit in the household appliance. Furthermore, the control unit is configured to control the drying on the basis of the evaluated physical quantities, a memory being provided for storing the physical quantities and / or the evaluated physical quantities. The memory can be integrated in the household appliance. Alternatively, a memory can be provided in the cloud. In particular, the current drying process is displayed on a screen integrated in or on the household appliance or an external screen. The drying process can be displayed, for example, on a mobile device or the like, whereby a remote monitoring of the drying is realized. In addition, predetermined setpoint values for various objects to be dried are stored in the memory. For example, a predetermined target temperature and / or a target air pressure and / or a target air flow are stored for an object made of cotton to be dried. The setpoint values, which are assigned to an object made of cotton, for example, are preferably combined in a group, here for example the “cotton group”. Setpoint values which are assigned to another object to be dried are assigned to a different group accordingly. During drying, the currently detected and evaluated physical variables are compared with the setpoint values of the different groups stored in the memory and the conditions are assigned after the assignment has been recognized a certain group, in particular with regard to the temperature and / or to the air flow and / or to the air pressure, adapted to the recognized objects to be dried. This has the advantage that the household appliance is designed to recognize the objects to be dried or their type each time a drying is carried out and to learn a drying-learning curve.

Preferably, the at least one sensor is a miniaturized sensor, in particular a MEMS chip (m icro e lectro m echanical s ystem) is. A MEMS chip advantageously combines mechanical and electrical detection properties. In particular, at least one PTH chip (pressure-temperature-humidity chip) is used to record the physical quantities. Air pressure, temperature and humidity can be detected with a PTH chip. 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 quantities 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 variables, in particular the specific enthalpy and / or the relative humidity or the like, and is configured to assign the thermodynamic variables to a predetermined type of objects to be dried. Various models are stored in the evaluation unit, which are used to evaluate the recorded physical quantities. Linear functions, power functions or logarithms or exponential functions or more complex, in particular composite, functions with which the detected physical quantities are evaluated in the evaluation unit to determine the thermodynamic quantities are preferably stored. For example, monomials and polynomials are stored which have an integer power to the power of 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 based on 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) for measuring the physical quantities are exposed to the circulating air flow. This means that the current conditions are better captured. With time-dependent detection of the physical quantities, the at least one sensor detects a time-dependent change in 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.

A sensor or at least two sensors are preferably arranged after a heat sink and / or in front of a heat source for the process air flow. In particular, a sensor is arranged at the drum inlet and / or at the drum outlet. When arranging a first sensor after the heat sink and when arranging a second sensor in front of a heat source or at the drum inlet and drum outlet, the same physical variable can be detected at two different points in the air flow at the same time. With only one sensor, the same physical variable can be recorded at two successive points in time. This has the advantage that different temporarily stationary thermodynamic, in particular atmospheric, conditions of the physical quantities can be recorded simultaneously at different points or one after the other at one point and then evaluated. In this way it can be determined with a higher correct probability which object to be dried is involved. In a laundry care device, such as a tumble dryer or washer dryer, the objects to be dried are textiles. By recording the physical parameters, it is possible to predict what kind of textiles to be dried are. The term "type of textiles to be dried" means the textile as such, for example a textile made of cotton, synthetic, wool, or a mixture of textiles.

According to a further preferred embodiment, a first sensor is arranged at one point and a second sensor for detecting at least one physical variable is arranged at a second point. The values of the physical variable recorded by the first and the second sensor are used by the evaluation unit to form the difference between the recorded physical variable of the first sensor and the recorded physical variable of the second sensor. For example, when forming the difference, an air pressure difference 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) is the air pressure in the air flow is at the position of the second sensor at time t0. Furthermore, the air pressure difference can be determined at two different times, namely at time t0 and at a later time t1. The difference is then calculated according to P (t1-t0) = p (t1) -p (t0). The formation of the difference can be carried out with any recorded physical variable, 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 for the controlled implementation of drying of objects in a household appliance. The method comprises the following steps: accommodating the objects to be dried in a container of the household appliance, at least one air line being in fluid connection with the container and an air stream flowing through the air line and through the container. The method further comprises detecting at least two physical variables selected from the group consisting of an absolute water load x, an air temperature T, an air pressure p or another physical variable which is dependent on the controlled performance of the drying, of at least one sensor arranged in the air stream. The method further includes transferring 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 to regulate the at least two physical quantities and the evaluated at least two physical quantities to a control unit To carry out drying. The at least one sensor used for the method can detect a plurality of physical variables, preferably at the same time and / or consecutively, in particular physical variables such as an absolute water load x, a temperature T, a pressure or the like. These physical quantities are dependent on the household appliance and the objects to be dried arranged in the household appliance. In other words, the recorded 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 the objects arranged in the household appliance are recognized by means of the proposed method and, after detection, can be gently dried 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 variables, in particular the control unit controls a container rotation, a reversing, a temperature or the like. The control controls the setting of the temporarily stationary thermodynamic conditions in such a way that the objects to be dried are dried under the most optimal conditions possible. This has the advantage that the objects to be dried are dried under gentle conditions.

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

The thermodynamic variables based are preferably at least one predictive model stored in the analysis unit determines, in particular based on a factory-set multivariate analysis with a PLS prediction method (P artial L east S quare). Several prediction models are preferably 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 include monomials and polynomials which have an integer power to the power of 2, 3, 4... N, where n is an integer, and / or polynomials of the type ± 1 / n, where n is an integer. As a result, the current thermodynamic conditions in the household appliance can be mapped in the best possible way using a multivariate analysis with a PLS prediction method.

According to the invention, each evaluated physical variable, in particular every specific thermodynamic variable, is compared with different setpoint values specified in the evaluation unit, each setpoint value being assigned to a specific group, with each group including factory-set setpoint values, in particular for recognizing the objects to be dried. 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 type of textile, for example wool, while a second group is assigned is assigned to another type of textile, for example synthetic. Different groups are preferably provided, such as a wool group, a cotton group, a synthetic group, a mixed group or the like. For example, the "wool" group includes setpoints with a low temperature and increased air flow, while the "cotton" group includes lower air flow and higher temperature. By comparing the specific thermodynamic variables with the factory-set target values stored in the evaluation unit, it is possible to assign the objects to be dried to at least one group, whereby the objects to be dried are recognized, in particular automatically, in the course of the drying process. The setpoint values set at the factory include setpoint values for the physical variables to be detected and / or for the thermodynamic variables to be determined.

According to a preferred embodiment, a first sensor is arranged at one point and a second sensor for detecting at least one physical variable is arranged at a second point. The evaluation unit forms the difference between the recorded physical variable of the first sensor and the recorded physical variable of the wide sensor. For example, when forming the difference, an air pressure difference 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) is the air pressure in the air flow the position of the second sensor at time t0. Furthermore, the air pressure difference can be determined at two different times, namely at time t0 and at a later time t1. The difference is then calculated according to P (t1-t0) = p (t1) -p (t0). The formation of the difference can be carried out with any recorded physical quantity, for example with the air temperature T (t), the absolute water load x (t) or the like, where t is the time.

Various models are preferably stored in the evaluation unit, which are used to evaluate the recorded physical quantities, preferably using linear functions or power functions or logarithms or exponential functions or more complex, in particular composite, functions with which, after the detected physical quantities have been recorded, the thermodynamic quantities in evaluated by the evaluation unit. This has the advantage that the objects to be dried can be reliably identified in real time.

The proposed household appliance and the associated method for controlled drying of objects to be dried that can be arranged in the household appliance advantageously avoid the destruction of the objects to be dried and at the same time ensure a good drying result by means of real-time recognition of the thermodynamic variables detected.

Fig. 1

ein schematisch dargestelltes Haushaltsgerät insbesondere ein Trockner,

Fig. 2

eine schematisch dargestellte Anordnung von Sensoren in einem Luftstrom in einem Haushaltsgerät gemäß Fig. 1, und

Fig.3

gegenüber der Zeit dargestellte erfasste physikalische Größen in einem Luftstrom gemäß Fig. 2.

Further advantages and features of the present invention emerge from the following description of preferred embodiments with reference to the figures of the attached drawing. It goes without saying that individual embodiments shown in the respective figures can have features that 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. Show it:

Fig. 1

a household appliance shown schematically, in particular a dryer,

Fig. 2

a schematically illustrated arrangement of sensors in an air flow in a household appliance according to Fig. 1 , and

Fig. 3

detected physical quantities in an air stream shown versus time according to FIG Fig. 2 .

In the following, the Figures 1 to 3 the present invention explained using a household appliance 10 in the form of a laundry care appliance. The following description of the illustration can be transferred analogously to another household appliance that conducts air, such as a dishwasher.

Fig. 1 shows a household appliance 10, in particular a laundry care appliance with a screen 12 and a container 14. Objects 20 to be dried, in particular textiles of various types, are arranged in the container 14. The household 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 executed by the household appliance 10 for the controlled implementation of drying of items arranged in the household appliance Objects to be dried can be started. The progress of the drying process can 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 included outside the household appliance in a cloud 26. Various prediction models are stored in the evaluation unit 24, 24 ′, with which predictions are made about the type of the concrete objects 20 to be dried. Setpoint values are stored in groups 40 in a memory 25, 25 ', each group 40 being assigned to predetermined objects to be dried. In particular, each group 40 is assigned to a type of textile such as cotton or wool or synthetic or a mixture of different textiles.

As in Fig. 2 Sensors 32 for detecting at least one physical variable, such as an air temperature T, an air pressure p, an absolute water load x, are schematically shown in the air stream 30 at various points. From the detected physical quantities, thermodynamic quantities, such as the specific enthalpy h and / or the relative humidity φ, are determined by means of the evaluation unit 24, 24 '. As Fig. 2 shows, a sensor 32 is arranged at a container outlet 34 and another sensor 32 is arranged in the middle of an air line 36. Furthermore, a sensor 32 is arranged after a lint filter 37 and in front of a fan 38. Fig. 2 shows possible locations in the air stream 30 at which a sensor 32 can be positioned in order to detect physical variables, in particular an absolute water load x, an air temperature T, an air pressure p or another physical variable that is dependent on the controlled implementation of the Has 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 quantities, in particular the specific enthalpy h and / or the relative humidity φ, based on the various prediction models, and then uses them in one of the evaluation units 24 , 24 associated memory 25, 25 'compares stored nominal values of different groups 40. After the best possible correspondence between the calculated thermodynamic variables and the setpoint 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 thermodynamically optimized conditions for performing the drying of the objects 20 to be dried to the control unit 22. The control unit 22 controls the container 14 and the fan 38 accordingly in order to set the optimal conditions for the drying in the domestic appliance 10. The air flow 30 can be adjusted by activating the fan 38, while the rotational speed of the container 14 can be adjusted by activating the container 14, in particular the drum. In the container 14, driver elements 42 are arranged to assist the circulation of the textiles arranged in the domestic appliance 10.

Fig. 3 shows schematically the physical quantities T, p, x detected by means of the sensors 32 or the at least one sensor 32 and the thermodynamic quantities h, φ calculated therefrom for two different objects 20 to be dried, for example wool and synthetic. For example, the detected physical quantities T, p, x and the thermodynamic quantities h, φ calculated from them were preferred based on 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 a drum outlet. The physical quantities T, x recorded over time and the thermodynamic quantities h, φ calculated from them are shown versus time. The setpoint values stored in the memory 25, 25 'assigned to the evaluation unit 24, 24' can also be stored in the form of setpoint curves. In this case, setpoint curves are compared with currently recorded curves of the thermodynamic quantities h, φ and / or the detected physical quantities T, p, x. At each position of a sensor 32 there is a temporal profile of the physical quantities T, p, x and the thermodynamic quantities h, φ, the shape, the gradient or the like being different. The different courses of the recorded and / or calculated curves are dependent on the textile moisture, the type of textile and / or the weave. In this way, the type of textile of the objects 20 in the household appliance can be determined. In particular, by assigning the recorded curves or the recorded values to a group 40, the objects 20 to be dried arranged in the household appliance 10 are recognized. On the basis of an initial detection of the loading 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 detection can be carried out more precisely.

List of reference symbols

10

Home appliance

12

screen

14th

container

16

Mobile device

18th

wireless data transmission

20th

items to be dried

22nd

control

24, 24 '

Evaluation unit

25, 25 '

Storage

26th

Cloud

30th

Airflow

32

sensor

34

Container outlet

36

Air duct

37

Lint filter

38

Fan

40

group

42

Driver element

h, φ

thermodynamic quantities

T, p, x

physical quantities

T

Air temperature

p

Air pressure

x

absolute water loading

H

specific enthalpy

φ

relative humidity

Claims (15)

1. Household appliance (10) for the regulated performance of a drying of objects (20) to be dried which can be arranged in the household appliance (10), wherein the household appliance (10) has:

   a container (14) for receiving the objects (20) to be dried, at least one air duct (36) which is fluidically connected to the container (14), wherein an air current (30) flows through the air duct (36) and through the container (14),

   wherein at least one sensor (32) for detecting at least two physical variables, 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 upon the regulated performance of the drying, is arranged in the air current (30), wherein the at least one sensor (32) is connected to an evaluation unit (24, 24'), which is configured to receive and evaluate the at least two physical variables from the at least one sensor (32) and to transmit the physical variables and/or the evaluated physical variables to a control unit (22) for the regulated performance of the drying,

   characterised in that

   the evaluation unit (24, 24') is designed to compare each evaluated physical variable, in particular each determined thermodynamic variable, with different setpoint values,

   wherein each setpoint value is allocated to a particular group (40),

   wherein the predetermined setpoint values of a group (40) are allocated to a type of objects (20) to be dried.
2. Household appliance (10) according to claim 1, wherein the evaluation unit (24) is arranged outside the household appliance (10), in particular in a cloud (26), is or can be wirelessly connected to the control unit (22), or the evaluation unit (24') is integrated in the household appliance (10) in the control unit (22), or is connected thereto, wherein the control unit (22) is configured to control the drying on the basis of the evaluated physical variables, wherein a memory (25, 25') is provided for storing the physical variables and/or the evaluated physical variables.
3. Household appliance (10) according to one of the preceding claims, wherein the at least one sensor (32) is a miniaturised 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 variables, in particular the specific enthalpy and/or the relative humidity or the like, and is configured to allocate the thermodynamic variables to a predetermined type of objects (20) to be dried.
5. Household appliance (10) according to one of the preceding claims, wherein the at least one sensor (32) is arranged at a transition between the air duct (36) and the container (14), in particular at a container entrance or a container exit (34), or are arranged in the air duct (36).
6. Household appliance (10) according to one of the preceding claims, wherein a sensor (32) is arranged after an evaporator and/or before a condenser.
7. Household appliance (10) according to claim 6, wherein a first sensor (32) is arranged at a point after the evaporator or on a drum entrance and a second sensor (32) is arranged at a second point before the capacitor or on a drum exit, for capturing at least one physical variable, and the physical variables captured by the first and the second sensor (32) are used by the evaluation unit (24, 24') to form a difference between the captured physical variable of the first sensor (32) and the captured physical variable of the further sensor (32).
8. Method for the regulated performance of a drying of objects (20) in a household appliance (10), wherein the method comprises the following steps:

   Drying the objects (20) to be dried in a container (14) of the household appliance (10),

   wherein at least one air duct (36) is fluidically connected to the container (14) and an air current (30) flows through the air duct (36) and through the container (14),

   wherein at least two physical variables, selected from the group consisting of an absolute water load x, an air temperature T and an air pressure, or another physical variable, which has a dependency upon the regulated performance of the drying, are detected by at least one sensor (32) arranged in the air current (30), and

   are passed on to an evaluation unit (24, 24'), which is configured to receive and evaluate the at least two physical variables from the at least one sensor (32) and to transmit the at least two physical variables and the evaluated at least two physical variables to a control unit (22) for the regulated performance of the drying,

   characterised in that

   each evaluated physical variable, in particular each determined thermodynamic variable, is compared with different setpoint values predefined in the evaluation unit (24, 24'),

   wherein each setpoint value is allocated to a particular group (40),

   wherein the predetermined setpoint values of a group (40) are allocated to a type of objects (20) to be dried.
9. Method according to claim 8, wherein the control unit (22) controls the drying on the basis of the evaluated physical variables, in particular controls a container rotation and a fan (38) in order to set optimum conditions for drying in the household appliance.
10. Method according to claim 8 or 9, wherein the evaluation unit (24, 24') determines thermodynamic variables from a plurality of physical variables, in particular the specific enthalpy and/or the relative humidity or the like, and allocates the thermodynamic variables to a predetermined type of objects (20) to be dried.
11. Method according to claim 10, wherein the thermodynamic variables are determined on the basis of a prediction model stored in the evaluation unit (24, 24'), in particular on the basis of a factory-set multivariant analysis using a PLS prediction model (Partial Least Square).
12. Method according to one of claims 8 to 11, wherein in order to identify the objects (20) to be dried, each group (40) comprises setpoint values which are predetermined at the factory.
13. Method according to claim 12, wherein a first group (40) is allocated setpoint values of one type of textile, for example wool, while a second group is allocated setpoint values (40) of another type of textile, for example synthetics.
14. Method according to one of claims 8 to 13, wherein a first sensor (32) is arranged at one point and a second sensor (32) is arranged at a second point in order to capture at least one physical variable, and the difference between the captured physical variable of the first sensor (32) and the captured physical variable of the second sensor (32) is formed by the evaluation unit (24, 24').
15. Method according to one of claims 8 to 14, wherein various models are recorded in the evaluation unit (24, 24'), which serve to evaluate the captured physical variables, wherein preferably power functions or logarithms or exponential functions or more complex, in particular composite functions are used, with which the thermodynamic variables are evaluated in the evaluation unit (24, 24') after capturing the detected physical variables.

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