DE202004021057U1 - State finding process for heat transfer device involves measuring at least one physical measuring variable of one heating medium during heat transfer - Google Patents

Abstract

The State finding process is applied to a heat transfer device through which at least two media flow, with heat being transferred between them. At least one physical measuring variable of at least one of the heat media is measured during heat transfer, and the value of at least one state variable depending on the measuring value and characterizing the state of the heat transfer device is determined on the basis of the measured values or of their measuring signals.

Description

The The invention relates to a device for determining a condition a heat transfer device.

Heat transfer equipment, also heat exchangers or heat exchanges called, are in manifold embodiments and known in a variety of applications. In a heat transfer device will heat from one through the heat transfer device flowing gaseous or liquid heat medium to another, also through the heat transfer device flowing gaseous or transferred fluid heat medium. For heat transfer can all heat transport mechanisms, ie heat conduction, heat convection and / or thermal radiation are used, wherein in the convection additionally a phase transformation or aggregate state change can be used by evaporation or condensation.

In The practice are as heat transfer devices mainly three types of heat exchangers in use, namely so-called recuperators or recuperative heat exchangers, regenerators or regenerative heat exchanger and direct contact heat exchanger. Regenerative heat exchangers are usually for used a discontinuous operation, while recuperators predominantly for the continuous Operation are used.

at Recuperators is a partition or heat transfer surface between the two streams of heat media arranged so that a heat transfer takes place through the heat transfer surface. As rekupera tive heat exchanger become mainly Tube heat exchanger or plate heat exchanger used. In a tube heat exchanger become several tubes usually arranged parallel to each other and one of the heat media gets through the inside of the tubes directed. The other heat medium flows against it outside at the tubes along. For a plate heat exchanger are individual plates arranged parallel to each other and one of heat media flows by one for this heat medium provided part of the interstices between the plates and the other heat medium through the other Part of the interstices between the plates. Serve as heat transfer surfaces at the tube heat exchanger the walls of the tubes and at the plate heat exchanger the plates themselves. As materials for the recuperative heat exchangers come into consideration materials that are corrosion resistant and have smooth surfaces, For example, glass, plastic-coated metals and stainless steels.

at a crossflow heat exchanger become the currents the two heat media crossed or orthogonal to each other, in a DC heat exchanger in the same direction and in a countercurrent heat exchanger in opposite Directions.

at the regenerative heat transfer Regenerators use storage masses that alternate with the heat-emitting and the heat-absorbing Medium, for example, the exhaust air flow and the supply air, in contact to be brought. Usually the storage mass is continuously rotated, for example housed in a cylindrical rotor by a motor is driven. The two fluid heat media flow through, usually in countercurrent, the storage mass of the regenerator and become and after the heat exchanger in separate channels guided.

A the most important applications of heat transfer devices is the heat recovery, especially in the field of industry. This is residual heat or waste heat or heat-up in a heat medium flowing away from a, in particular industrial, process, For example, exhaust or exhaust air, for own use in the process or also for foreign use in other processes or for heating purposes at least partially recovered. The most frequent Own use in the process is the preheating of the other heat medium, For example, the supply air, which is then used in the process.

In the heat transfer and heat recovery Exhaust air is always the presence of water or moisture in the air, to the condensation of water in the Heat exchanger can lead and for to consider the so-called exchange number of heat recovery is. The exchange number defines the intensity or the heat recovery Efficiency or the efficiency of transfer of heat and Moisture from the one medium, z. B. exhaust, to the other medium z. B. supply air.

In the recovery of heat from exhaust air, the three physical parameters of temperature, enthalpy and humidity of the supply air on the one hand and the exhaust air on the other hand for the transferred heat flow of importance tung. One differentiates between the exchange numbers for the enthalpy, for the temperature and for the humidity. The exchange number for the enthalpy transmission corresponds to the quotient of the difference between the enthalpy of the incoming air after the heat exchanger and the enthalpy of the supply air before the heat exchanger on the one hand and the difference of the enthalpy of the exhaust air before the heat exchanger and the enthalpy of the exhaust air to the heat exchanger on the other. The exchange rate for the temperature transfer, ie the temperature efficiency, is defined as the quotient of the difference between the temperature of the supply air to the heat exchanger and the temperature of the supply air upstream of the heat exchanger on the one hand and the difference of the temperature of the exhaust air before the heat exchanger and the temperature of the exhaust air after the heat exchanger on the other. Accordingly, the exchange number for the moisture transmission is defined as the quotient of the difference between the moisture content of the supply air to the heat exchanger and the moisture content of the supply air before the heat exchanger on the one hand and the difference in the moisture content of the exhaust air before the heat exchanger and the moisture content of the exhaust air to the heat exchanger on the other.

Of the heat exchange between the heat media in the heat transfer device is the more efficient the closer the exchange number is 1.

at negligible Exchange the exchange numbers go against 0 and with ideal exchange against 1. The size of the exchange numbers depends on the type of heat exchanger as well as from the flow guide.

The Exchange numbers are used in the design of heat exchangers for optimization of their efficiency and heat transfer behavior fixed once. However, a once designed heat exchanger is in Operation then no longer in terms of its heat transfer behavior or its current exchange rate is checked or monitored. This may result in a deterioration of the efficiency of a heat exchanger in a heat recovery system come to significant energy losses. Such a deterioration For example, the efficiency can be due to pollution or clogging in the heat exchanger or a pipe or a break or crack in a glass tube of a Rohrwärmtauschers or by aging or even material wear or corrosion

These Problem is but in the practice of industrial heat recovery either not at all perceived or accepted.

Of the Invention is based on the object, a device for determining a state of a heat transfer device specify.

These Task is according to the invention solved with the features of claim 1.

The Invention is based on the consideration the state and / or the heat transfer behavior a heat exchanger while of operation by measuring selected quantities of at the heat transfer involved heat media and evaluate the obtained measured values or measurement signals and thus the user values of parameters for the state, in particular the heat transfer behavior, of the heat exchanger while of the operation or during the heat transfer process to disposal to deliver.

At the The prior art may be a once set or designed Heat transfer characteristic a heat exchanger while of the operation can no longer be determined or checked and thus the actual Heat transfer characteristic from the desired Characteristic or the actual state of the heat exchanger from its desired state vary significantly without any quantitative analysis could.

The Invention allows however, for the first time, a quantitative assessment or analysis of the actual state or the actual characteristic of a heat exchanger during its Use or operation, for example in heat recovery.

The user can now directly "online" get the current values of the characteristic values on a display unit, eg his process control system or process control system (visualization) Furthermore, the determined values or characteristics of the characteristic quantities or the primary measured values and measurement signals over predetermined, longer Periods are stored ("histories") and with these stored histories also in hindsight or evaluations or analyzes of the heat transfer systems are made. With these measures is a continuous review and monitoring of the heat during the entire period of operation possible, in particular in the context of process control tasks or in an existing process control system for an entire system in which the heat transfer or heat recovery plant is integrated as a component. Finally, with the aid of the invention it is also possible to (again) optimize the heat transfer behavior of a heat exchanger during operation by changing the manipulated variable (s) in such a way that the parameter (s) again lie or lie in a desired range.

advantageous Embodiments and developments and applications of the device arise from the dependent claim 1 dependent claims.

The The invention will be further explained below with reference to exemplary embodiments. there is referred to the drawing, in whose

1 a heat recovery system in a process air system in a schematic diagram,

2 the calculation of physical quantities of an air stream according to 1 from its measured variables temperature and relative humidity in a diagram,

3 the calculation of the temperature efficiency of a heat exchanger of the heat recovery system according to 1 in a diagram,

4 the calculation of a compensated volumetric flow or mass flow of the air flows according to 1 in a diagram,

5 the calculation of the heat quantity efficiency of a heat exchanger according to 1 in a diagram,

6 the calculation of the transmitted heat output and the transferred heat amount of a heat exchanger according to 1 in a diagram, the calculation of the heat quantity efficiency of a heat exchanger according to 1 in a diagram,

7 the calculation of the temperature in the heat exchanger according to 1 resulting condensate in a graph,

8th the calculation of the mass flow of in the heat exchanger according to 1 resulting condensate in a graph,

9 the detection of a glass tube break in the heat exchanger according to 1 by evaluation of moisture loadings in a graph and

10 the detection of a glass tube break in the heat exchanger according to 1 by evaluation of mass flows in a graph
are each shown schematically. Corresponding parts and sizes are in the 1 to 10 provided with the same reference numerals.

In 1 a process air system is shown, which is a process area 2 via an air inlet 3 Supply air ZL feeds and from the process area 2 via an exhaust outlet 4 Exhaust air ABL dissipates.

A supply air fan 5 to suck in outdoor air AL from an outdoor area, usually atmospheric air or indoor air, to, at an entrance 21 in a heat exchanger 10 flows and the heat exchanger 10 flows through. and at an exit 22 as supply air ZL flows out again to the supply air fan 5 , In at least one heating device 31 is the supply air ZL, after the supply air fan 5 and in front of the air intake 3 heated to a predetermined temperature necessary for conditioning or supply of the process area 2 with process air is desired.

The process area 2 For example, it may be a paper or pulp machine and the supply air ZL used to dry the paper or pulp webs in the machine. In this case, air temperatures of the supply air ZL are usually set from 110.degree. C. to 120.degree. The invention is not limited to this application.

Simultaneously with feeding the supply air ZL into the process area 2 gets from the process area 2 via the exhaust outlet 4 the exhaust air ABL by means of an exhaust air fan 6 sucked off and over another entrance 23 of the heat exchanger 10 in the heat exchanger 10 initiated, led by this and at another exit 24 of the heat exchanger 10 as exhaust air FL discharged again to exhaust air fan 6 out.

The Exhaust air ABL still contains a considerable amount of residual heat. at In a paper machine, the exhaust ABL typically has temperatures from between 70 ° C and 90 ° C.

The waste heat contained in the exhaust air ABL is now at least partially in the heat exchanger 10 recovered by preheating or heating the outside air AL or to provide preheated supply air ZL, then from the heater 31 is brought to the final temperature is used. Thus, for example, the outside air AL can be brought from an outside temperature of typically - 15 ° C to + 30 ° C to a pre-temperature of + 50 ° C to + 70 ° C, they then as supply air ZL when exiting the heat exchanger 10 having.

The heat exchanger 10 is for example designed as a cross-flow tube heat exchanger, in the vertical glass tubes of the exhaust air flow ABL is guided vertically from bottom to top and outside of the glass tubes along the outside air flow AL is guided horizontally. In this version, condensate of the exhaust air ABL can flow off more easily downwards. However, other types and designs of heat exchangers are usable.

In addition, to increase energy efficiency, additional residual heat from the heat exchanger 10 exiting, usually still 60 ° C to 65 ° C warm exhaust air FL in another heat recovery unit 30 For example, an air / water / heat exchanger with a water cycle 32 with a pump, be withdrawn. This in the heat recovery 30 recovered heat of the exhaust air FL can be used for example for heating and / or for air conditioning of the hall or building air.

The heat exchanger 10 are now four sensor devices 11 to 14 assigned. The sensor device 11 is in front of the entrance 21 of the heat exchanger 10 is connected in the flow path of the outside air AL and measures external air quantities AL. The sensor device 12 is the exit 22 of the heat exchanger 10 arranged downstream in the flow path of the supply air ZL and measures measured variables of the supply air ZL. The sensor device 13 is in front of the entrance 23 of the heat exchanger 10 connected in the flow path of the exhaust air ABL and measures measured variables of the exhaust air ABL. The sensor device 14 after all, is behind the exit 24 of the heat exchanger 10 switched into the flow path of the exhaust air FL and measures measured variables of the exhaust air FL.

The water cycle 32 the optional heat recovery unit 30 is also a sensor device 16 assigned to the measurement of measured quantities of water.

The sensor devices 11 to 14 and 16 can have analog or digital sensors. In analog sensors whose sensor or measuring signals are preferably digitized and further processed in the form of digital signals. Basically, of course, an analog signal processing of the analog measurement signals is possible. With digital sensors, these provide digital measuring signals or measured values at their outputs.

The, preferably digital, outputs of the sensor devices 11 to 14 and 16 are each connected to inputs of an evaluation device (or: evaluation unit) 7 connected. The evaluation device 7 can with one or more sensor devices 11 to 14 be integrated in a unit or operated as a separate structural unit and / or self-sufficient.

The evaluation device 7 evaluates those of the sensor devices 11 to 14 obtained measured values or measurement signals and determines therefrom physical variables, at least physical parameters for the current heat transfer behavior and / or the state of the heat exchanger 10 , The evaluation device also evaluates 7 the measured values or measuring signals of the sensor device 16 from and determines one or more characteristic (s) of the heat recovery 30 , For evaluation includes the evaluation 7 In general, at least one digital signal processor or microprocessor and associated memory for storing determined data and stored control and computation programs and possibly of value tables.

The evaluation results, ie the determined digital, in particular binary, values of the parameters, transmits the evaluation device 7 via a data bus or a bus interface to a higher level process control system 8th , Standard bus technology such as Ethernet (TCP / IP) or Profibus can be used here.

The process control system 8th is intended only for the heat recovery system or for the entire process air system or even for the entire process, here for example the paper or cellulose production process in the paper or cellulose machine.

On a display device (or: display unit) 9 of the process control system 8th , in general, a graphical screen (display), such as a computer monitor, are those of the evaluation 7 obtained values of the characteristics of the heat exchanger 10 and possibly the heat recovery 30 at least partially visualized or graphically represented, in particular in the form of numbers behind associated identifiers or physical symbols or in the form of curves, diagrams or similar known types of display.

The user thus receives on the display device 9 Continuous information on important parameters of the heat recovery part of his plant and can change the state of the heat exchanger 10 and possibly the heat recovery 30 evaluate and monitor and if necessary optimize or correct. For the plant operator or user, the heat recovery system becomes transparent and plant availability is increased, analyzes of system economics can be made, decisions on energy optimization can be supported, and on-demand maintenance can be facilitated. In process control systems, the know-how about heat recovery systems can be made available and can be integrated into overall concepts. Heat recovery systems themselves are upgraded with intelligent evaluation

The sensor devices 11 to 14 for the heat exchanger 10 preferably comprise individual sensors for measuring the temperature t, the relative humidity φ and the volume flow or the pressure, in particular differential pressure, in particular back pressure, of the associated air flow. Proven sensor technology for temperature, humidity, volume flow and pressure measurement can be used here.

For temperature measurement can For example, resistance temperature sensor used become. For The direct volume flow measurement can be flow meter, for example Ultrasonic, eddy frequency induction or anemometer flow sensors, Back pressure or throttle meters be used. For The pressure measurement or differential pressure measurement can be piezoelectric or mechanical, membrane or spring pressure sensors are used.

To the For example, measuring relative humidity becomes capacitive humidity sensors used. But you can also instead of or in addition to relative humidity measure the absolute humidity or moisture loading x, For example, directly by means of a LiCl-humidity sensor whose transformation temperature of the absolute humidity depends or indirectly by means of a dew point temperature sensor, for example a dew point mirror.

Of the Water content of the air comprises substantially not yet saturated state Water vapor (or: moisture, proportion of water in gaseous state) and in the supersaturated Condition in addition also carried or floating water droplets (or: water in liquid Shape). At saturation or the associated saturation pressure prevails at a constant temperature balance between a liquid and their vapor in a given arbitrary volume.

The absolute humidity or the absolute water vapor content or the moisture loading x corresponds to the quotient of the mass of the water vapor (vapor mass) contained in the air, measured, for example, in grams (g), and the mass of the dry air (dry matter mass), usually expressed in kg, where both masses are determined in the same volume of gas, for example one cubic meter (1 m ³ ), at the same temperature and at the same pressure. The absolute vapor content or the moisture loading X is therefore a dimensionless quantity.

The relative water vapor content or the relative humidity φ is based on the saturation state and is defined as the quotient of the partial density or concentration of the water vapor at the predetermined temperature, for example measured in g / m ³ , and the saturation partial density of the water vapor which occurs when the saturation partial pressure is reached of the water, at the same temperature set or adjust and is also measured in g / m ³ . The relative humidity also corresponds to the quotient of the current steam partial pressure and the saturation vapor partial pressure. The relative humidity is dimensionless and is usually given in percent (%), whereby in the subsatured state the relative humidity is below 100% and in the saturated state is 100%. With a higher temperature, the relative humidity decreases while the absolute humidity remains the same.

From the of the sensor devices 11 to 14 measured physical quantities temperature, humidity (rel.) And flow / pressure can a variety of other, dependent of these variables physical variables of the heat recovery system with the heat exchanger 10 from the evaluation device 7 can be calculated numerically, for example, with stored analytical functions, equations, formulas or with fit functions or interpolation, or be assigned based on given tables of values or curves or diagrams.

• • die Feuchtebeladung ( = absoluter Wassergehalt) x,
• • die Dichte ρ,
• • die Enthalpie (Energieinhalt) h und
• • die Taupunkttemperatur t_t,

berechnet oder bestimmt werden können. 2 shows in a graph, such as from the measured variables temperature t and relative humidity φ each individual air flow with associated water content due to based on the Mollier diagram (or: hx diagram) oriented relationships or other physical parameters such as

• • the moisture load (= absolute water content) x,
• • the density ρ,
• • the enthalpy (energy content) h and
• • the dew point temperature t _t ,

can be calculated or determined.

in the Mollier diagram is the enthalpy h of the humid gas, usually humid air, over whose moisture loading x is plotted (hence: hx-diagram), where on two orthogonal axes of the diagram on the abscissa the Moisture loading x and read the temperature t on the ordinate can be. There are isotherms starting from the corresponding ones Temperature values on the ordinate as a straight line with with the temperature increasing slope. Furthermore, the Mollier diagram contains isenthalpen, the right parallel to the lower parallel straight line with the slope are the negative enthalpy of vaporization, as well as convex curved Parameter curves of equal relative humidity φ, where the saturation curve for φ = 100% farthest down and above this saturation curve are the curves for φ <100%, ie the Area of subsaturation and below the area of supersaturation or fog area.

The in the Mollier diagram graphically displayed relationships are in Given below in the form of the corresponding equations or formulas.

Predefined or predefinable constants or constant system sizes:
System pressure: p _sys = const.
Heat capacity air: c _pl = const.
Heat of evaporation water; r = const.
Heat capacity water vapor: c _pd = const.
Saturation pressure water vapor: p _{s (t)} is determined from temperature t according to stored table (with interpolation)

With the four temperature values t _{AL of} the sensor device 11 , t _{ZL of} the sensor device 12 , t _{ABL of} the sensor device 13 and t _{FL of} the sensor device 14 is according to 3 now from the evaluation device 7 as the first parameter for the heat transfer in the heat exchanger 10 the current temperature efficiency (or: thermal efficiency, temperature exchange rate) η _{th of} the heat exchanger 10 is calculated as the quotient of the difference t _ZL - t _AL and the difference t _ABL - t _FL and the process control system 8th for display on the display device 9 transfer.

4 shows how initially from the one of the sensor devices 11 to 14 or 16 measured difference pressure in the corresponding flowing heat medium, an uncompensated volume flow of the medium with the predetermined parameters of the flow cross-sectional area A and the proportionality constant k of the sensor device (the measuring element) is calculated and then with the according 3 determined density ρ of the medium of this volume flow is densely compensated and also a corresponding density-compensated mass flow is determined.

The compensated volumetric flows or mass flows of the media, eg AL, ZL, ABL, FL, according to 1 Now be advantageous from the evaluation 7 to calculate more on the display device 9 Characteristics of the heat exchanger to be displayed 10 used and can also self on the display device 9 being represented.

So is according to 5 the current heat quantity efficiency η _{Q of} the heat exchanger 10 calculated from the four according to 3 determined enthalpies h _{AL of} the outside air AL, h _{ZL of} the supply air ZL, h _{ABL of} the exhaust air ABL and h _{FL of} the exhaust air FL according to 1 and according to 4 determined mass flows m _{ZL of} the supply air ZL and m _{FL of} the exhaust air FL.

6 FIG. 12 shows the calculation of the heat output Q transferred from the exhaust air ABL to the outside air AL and the heat transfer energy Q Q of the heat exchanger obtained by numerical summation or integration over the heat output Q over time 10 ,

By cooling the exhaust air ABL in the heat exchanger 10 may cause condensation. According to predetermined specific for the respective heat exchange process relationships, the condensate temperature of the heat exchanger according to 1 arising condensate according to 7 from the measured values for the temperature and the relative humidity and with the aid of the hx diagram. For this purpose, preferably the taut t _{t is used} as the condensate temperature.

8th shows the calculation of the mass flow of in the heat exchanger according to 1 resulting condensate or the amount of condensate to be discharged as a difference from the mass flow of the exhaust air ABL at the entrance 23 of the heat exchanger 10 and the mass flow of the exhaust air FL at the output 24 of the heat diver 10 ,

9 and 10 Now show embodiments in which a glass tube break in a glass tube heat exchanger 10 from the evaluation device 7 recognized and on the display device 9 can be displayed. It is exploited that a glass tube break leads to an exit of exhaust air ABL or contained therein water vapor, which can be detected by measurement.

In a arranged on the pressure side of the exhaust fan heat exchanger 10 preferably according to 9 the determined absolute humidity loadings x _{AL of} the outside air AL and x _{ZL of} the supply air FL are compared or balanced with a formula to detect a break or crack of the glass tube (s).

On a suction side of the exhaust air fan 6 arranged heat exchanger 10 Preferably, the determined mass flows of outside air AL and supply air ZL are balanced with a formula as in 10 shown.

By The supervision the glass tubes can be an invalid Humidification of the dry process supply through the highly charged Exhaust air in a glass tube break avoided.

All Measured value calculations are preferably pressure and temperature compensated.

With the in the evaluation device 7 or the process control system 8th Long-term recorded data, the heat recovery system can be additionally evaluated in terms of its efficiency, possibly optimized or renewed.

Optionally, also a contamination and / or blockage on or in the heat exchanger 10 monitored on both transmission sides by system changes. For this purpose, at least one additional differential pressure sensor for measuring a pressure difference between the input 21 and the exit 22 or preferably between the entrance 23 and the exit 24 of the heat exchanger 10 provided, preferably in the sensor devices 11 and 12 respectively. 13 and 14 , This improves availability and maintenance planning.

In an optimization function for air-to-air heat recovery in the heat exchanger 10 as an additional option, the calculated data can be used to optimize the heat flow capacities of the evaluation device 7 be performed. Thus, optimum energy utilization is guaranteed at every operating point.

In an optional optimization function for the air-water heat recovery in the heat exchanger 30 can with the help of the calculated data and with the additional use of volume flow in the water cycle 32 (Eg ultrasound meter) an optimization of the heat flow capacity of the evaluation 7 be performed. Thus, optimum energy utilization is guaranteed at every operating point.

In particular, the efficiency or the heat transfer can be optimized in that the heat flow capacity of a heat medium, ie AL or ZL in the heat exchanger 10 or water in the water cycle 32 of the heat exchanger 30 , On the one hand and the heat flow capacity of the other heat medium, ie ABL or FL, on the other hand be set equal to each other. The heat flow capacity corresponds to the product of heat capacity and mass flow of the heat transfer medium. As a manipulated variable for the optimization, therefore, the mass flow of at least one medium, for example AL or water, while the mass flow of the other medium, for example ABL, can be performed by the process.

The numerical calculation must of course in all embodiments do not follow the stepwise sequence of physical formulas, but can also be used immediately to reduce rounding errors the input variables, for example use equations solved for temperature t or relative humidity φ.

2

process area

3

air intake

4

air outlet

5

supply air fan

6

Exhaust fan

7

evaluation

8th

process Control System

9

display

10

heat exchangers

11 until 14

sensor device

16

sensor device

21

entrance

22

output

23

entrance

24

output

30

heat exchangers

32

Water cycle

AL

outside air

ZL

supply air

ABL

exhaust

FL

Exhaust air

Claims (30)

Apparatus for determining a condition of a Heat transfer means, through the at least two heat media stream and in a heat transfer process a heat transfer between the at least two heat media takes place, comprising a) at least one measuring device for Measuring at least one physical measurand of at least one of the heat media while the heat transfer process, b) at least one evaluation device connected to each measuring device is connected and from the measured values or measurement signals of the measured variable (s) at least an associated one Value of at least one of the or the measured variable (s) dependent and the state of Heat transfer device characterizing or descriptive physical state variable determined. Apparatus according to claim 1, wherein the measuring device measure or measure a temperature of at least one of the heat media can. Apparatus according to claim 1 or claim 2, wherein the measuring device of at least one of the heat media a volume flow of the heat medium or one with the volume flow of the heat medium in a clear relationship standing physical quantity, for example measures or measures a differential pressure or pressure in the heat medium can. Device according to one or more of the preceding Claims, at least one of the heat media gaseous is, in particular consists essentially of air and water and / or Air from the earth's atmosphere is. Apparatus according to claim 4, wherein the measuring device the relative humidity or the absolute humidity or one with the relative humidity or absolute humidity in a clear context standing physical quantity, in particular measures or measures the dew point temperature, of the or each gaseous heat medium can. Device according to one or more of the preceding Claims, at least one of the heat media liquid is, in particular at least predominantly consists of water. Device according to one or more of the preceding Claims, in which the measuring device at least one measured variable at least one of the heat media both before flowing through the heat transfer device as well as after flowing through the heat transfer device measures. Device according to one or more of the preceding Claims, in which the evaluation device is the state of the heat transfer device, in particular the heat transfer process in the heat transfer device, characterizing or descriptive state variable temperature efficiency determined, preferably the quotient of the difference of measured temperature value of the heat medium to which the heat transfer device the heat transfers, before flowing through the heat transfer device and the measured temperature value of this heat medium after flowing through the Heat transfer device on the one hand and the difference of the temperature value of the heating medium, of which the heat transfer device the heat withdraws, before flowing through the Heat transfer device and the temperature value of this heat medium after flowing through the Heat transfer device on the other hand corresponds. Device according to one or more of the preceding Claims, in which the evaluation device is the state of the heat transfer device, in particular the heat transfer process in the heat transfer device, characterizing or descriptive state variable determines a heat quantity efficiency, which preferably corresponds to the quotient of that with, preferably dichroduced, Mass flow of the heat medium, on the the heat transfer device the heat transfers, after flowing through the heat transfer device multiplied difference of the enthalpy of the heat medium to which the heat transfer device the heat transfers, before flowing through the heat transfer device and the enthalpy of this heat medium after flowing through the heat transfer device on the one hand and with the, preferably density-compensated, mass flow the heat medium, of which the heat transfer device the heat withdraws, after flowing through the Heat transfer device multiplied difference of the enthalpy of the heat medium from which the heat transfer device the heat withdraws, after flowing through the heat transfer device and the enthalpy of this heat medium before flowing through the heat transfer device on the other hand corresponds. Device according to one or more of the preceding Claims, in which the evaluation device is the state of the heat transfer device, in particular the heat transfer process in the heat transfer device, characterizing or descriptive state variable the transmitted heat output determined, preferably the product of the density-compensated Mass flow of the heat medium, on the the heat transfer device the heat transfers, on the one hand and the difference of the enthalpy of this heat medium before flowing through the Heat transfer device and the enthalpy of this heat medium after flowing through the heat transfer device on the other hand corresponds. Device according to one or more of the preceding Claims, in which the evaluation device is the state of the heat transfer device, in particular the heat transfer process in the heat transfer device, characterizing or descriptive state variable the transferred heat work, preferably by integration or summation of the heat output over the Time, determined. Device according to one or more of the preceding Claims, at which the evaluation device from the measured values of the temperature and the relative or absolute humidity of any or all gaseous heat medium the enthalpy of the heat medium determined. Device according to one or more of the preceding Claims, at which the evaluation device from the measured values of the temperature and the relative humidity of one or each gaseous heat medium, the absolute humidity of the heat medium determined. Device according to one or more of the preceding Claims, at which the evaluation device from the measured values of the temperature and the absolute or relative humidity of one or each gaseous heat medium the density of the heat medium determined. Device according to one or more of the preceding Claims, at which the evaluation device from the measured values of the temperature and the absolute or relative humidity of one or each gaseous heat medium the dew point temperature of the heat medium determined. Device according to one or more of the preceding Claims, at which the evaluation device from the measured values of the temperature and the absolute or relative humidity on the one hand and the volume flow or with the volume flow of the heat medium in a clear relationship standing physical size, in particular the differential pressure or pressure, on the other hand, a density-compensated Volume flow or mass flow of one or each gaseous heat medium determined. Apparatus according to claim 16, wherein the evaluation device determines the density-compensated flow or the density-compensated Volume flow the quotient of the measured volume flow or from the corresponding measured physical quantity, in particular the differential pressure or pressure, determined volumetric flow on the one hand and the square root of the density, in particular of the determined Density is proportional. Apparatus according to claim 16, wherein the evaluation device determines the density-compensated mass flow or density-compensated Mass flow of the product from the measured volume flow or from the corresponding measured physical quantity, in particular the differential pressure or pressure, determined volume flow on the one hand and the square root of the density, in particular of the determined Density is proportional. Device according to one or more of the preceding Claims, in which the evaluation device a leakage, in particular a breakage or crack, in the heat transfer device recognizes, in particular by evaluating the absolute humidity and / or of, preferably densely compensated, mass flow at least one of the heat media before and after flowing through the heat transfer device. Device according to one or more of the preceding Claims, in which the evaluation device, the amount, in particular the, preferably density-compensated, mass flow, of emerging in the heat transfer device Condensate of at least one heat medium, in particular the heat medium, of which the heat transfer device the heat deducts, from the, in particular density-compensated, mass flows this heating medium before and after flowing through the heat transfer device determined. Device according to one or more of the preceding Claims, in which the evaluation device, the temperature of the heat transfer device resulting condensate at least one heat medium, in particular the Heat medium, on the the heat transfer device the heat transfers through Evaluation of the temperature and relative humidity of this heat medium determined or the measuring device, the temperature of in the Wärmeübertra transmission device resulting condensate at least one heat medium, in particular the Heat medium, on the heat transfer device the Heat transfers through Evaluation of the temperature and relative humidity of this heat medium measures directly. Device according to one or more of the preceding Claims, in which the display unit, in particular a process control system or a control room or surveillance and / or control room, the measured values of at least one measured variable and / or the determined values of at least one of the state of the heat transfer device characterizing or descriptive state variable and / or the determined values of at least one on the basis of the measured values or Indicates measured signals determined physical size during the heat transfer process or represents. Device according to one or more of the preceding Claims, in which the measuring unit the measured variable (s) in a variety of measuring processes while a heat transfer process and in which the evaluation unit preferably measures the measured values or stores measurement signals from several measurement processes and for evaluation the state of the heat transfer device to disposal presents or evaluates. Device according to one or more of the preceding Claims, in which the evaluation device a contamination or clogging in the heat transfer device by measuring a differential pressure of at least one of the heat media at the heat transfer device detects or determines. Device according to one or more of the preceding Claims, in which each of the product of the heat capacity and the determined, preferably densely compensated, mass flow corresponding heat flow capacities of both heat media are set substantially equal to each other by bodies at least one of the mass flows. Apparatus for conditioning a process area, a) which supplies at least one fluid feed medium to the process area and b) discharges the at least one fluid discharge medium from the process area, c) the feed medium and the discharge medium being passed through at least one heat transfer device and the heat transfer device transfers heat from the discharge medium into the feed medium or from the feed medium into the discharge medium, d) which uses a device according to one or more of the preceding claims for determining the state of the heat transfer device. Apparatus according to claim 26, wherein the feed medium and / or the discharge medium gaseous is. Apparatus according to claim 27, wherein the feed medium and / or the discharge medium Contain water or moisture. Device according to one of claims 1 to 28, wherein the measuring device a) an input of the heat transfer device for a first of the heat media associated first sensor device for measuring at least one Measured variable of the first heating medium before flowing through the Heat transfer means, b) an output of the heat transfer device for the first heat medium associated second sensor device for measuring at least one Measured variable of the first heating medium after flowing through, c) a further input of the heat transfer device for a second the heat media associated third sensor device for measuring at least one Measured variable of the second heating medium before flowing through the heat transfer device and d) one output of the heat transfer device for the second heat medium associated fourth sensor device for measuring at least one Measured variable of the second heating medium after flowing through the heat transfer device includes. Device according to one of claims 1 to 29, wherein at least two heat transfer devices one behind the other in the flow path one of the heat media are connected and each heat transfer device this heat medium Heat escapes and transfers to another heat medium.