METHOD FOR THE CONDITIONING OF AIR, AND AIR-CONDITIONING SYSTEM

Abstract

In order to provide a method for the conditioning of air which is implementable in a reliable and energy-efficient manner, it is proposed that the method comprise the following: determining the actual values of at least two parameters of an inlet air stream of a conditioning system in which the air is to be conditioned; selecting an operating state of the conditioning system on the basis of a model by means of which a plurality of possible actual values of the at least two parameters is linked to operating states of the conditioning system; setting the conditioning system into the selected operating state so that an output air stream of the conditioning system is produced in which the actual values of the at least two parameters lie within preset target value ranges.

Description

The present invention relates to a method for the conditioning of air.

Such a method is known from EP 1 081 442 A1 for example. This known method is a regulated method wherein a conditioning system is regulated by means of regulated actuators. Thereby, at least one of the regulator input variables that are needed for the regulation of the conditioning system is a mixed regulator input variable which is formed by linking a deviation from the target temperature value with a deviation from the target humidity value.

The object of the present invention is to provide a method for the conditioning of air which is implementable in a reliable and energy-efficient manner.

In accordance with the invention, this object is achieved in that the method for the conditioning of air comprises the following:

• • determining the actual values of at least two parameters of an inlet air stream of a conditioning system in which the air is to be conditioned;
  • selecting an operating state of the conditioning system on the basis of a model by means of which a plurality of possible actual values of the at least two parameters is linked to operating states of the conditioning system;
  • setting the conditioning system into the selected operating state so that an output air stream of the conditioning system is produced in which the actual values of the at least two parameters lie within preset target value ranges.

Due to the fact that, in accordance with the invention, an operating state is selected on the basis of a model, a desired output air stream of the conditioning system can preferably be produced rapidly, reliably and/or in energy-efficient manner.

In this description and the accompanying Claims, it is to be understood in particular that a target value range is a range or a span of values within which a desired parameter may move in order to ensure the desired properties of the air stream.

In particular, the model is a static and/or a dynamic model.

In one embodiment of the invention, provision is made for the operating state of the conditioning system to be selected on the basis of a parameter map by means of which a plurality of possible actual values of the at least two parameters is linked with the operating states of the conditioning system.

Furthermore, provision may be made for the operating state of the conditioning system to be selected on the basis of a correlation function by means of which a plurality of possible actual values of the at least two parameters is linked with the operating states of the conditioning system.

In this description and the accompanying Claims, a correlation function is preferably to be understand as any equation and any set of equations and in particular model equations and sets of model equations by means of which a connection between at least one input quantity and at least one output quantity is established.

The parameter map and/or the correlation function are preferably based on the model upon the basis of which the operating state of the conditioning system is selected.

In particular, provision may be made for the parameter map and/or the correlation function to be or to have been established or produced by using or upon the basis of a model.

In particular, the model is a simulation model and especially a simulation model of the conditioning system or a work-piece processing system which incorporates the conditioning system.

By means of the model and preferably using the actual values of the at least two parameters of the inlet air stream and with knowledge of the operating state of the conditioning system, the actual values of the at least two parameters of the output air stream of the conditioning system can be determined and especially computed and/or predicted.

In particular in the inverse situation, it is additionally preferably possible by means of the model and with knowledge of the preset target value ranges of the at least two parameters of the output air stream of the conditioning system and by use of the determined actual values of the at least two parameters of the inlet air stream to deduce a desired operating state of the conditioning system.

In particular, a parameter map can be produced by means of the model from which, by using the determined actual values of the at least two parameters of the inlet air stream, an optimized and/or particularly energy-efficient operating state of the conditioning system is derivable.

In particular, provision may be made for control signals for the conditioning system by means of which the conditioning system is settable into the desired operating state to be providable by means of the parameter map.

Alternatively or in addition to a parameter map, provision may be made for a correlation function by means of which a plurality of possible actual values of the at least two parameters is linked with the operating states of the conditioning system.

Particularly when the conditioning system is in operation, an efficient operating state of the conditioning system can be computed by means of the correlation function on the basis of the model using the determined actual values of the at least two parameters of the inlet air stream in order to ensure adherence to the target value ranges of the parameters of the output air stream.

It can be expedient for one parameter to be the air temperature.

A (further) parameter is preferably the air humidity (moisture content).

It can be particularly advantageous if the at least two parameters form a pair of parameters consisting of the air temperature and the air humidity (moisture content).

It can be expedient for the inlet air stream to be heated up and/or cooled.

As an alternative or in addition thereto, provision may be made for the inlet air stream to be humidified and/or dehumidified.

In one embodiment of the invention, provision is made for a plurality of possible actual value combinations and in particular pairs of actual values of the at least two parameters to be linked with a respective operating state of the conditioning system by means of the model.

In particular, provision may be made for an operating state of the conditioning system to be associated with the plurality of possible pairs of actual values, especially the air humidity and the air temperature together, by means of the model.

In particular, a plurality of possible actual values of the at least two parameters is linked with pre-defined operating states of the conditioning system by means of the model, the parameter map and/or the correlation function.

The operating states of the conditioning system preferably each comprise an operating state of a humidification device, an operating state of a dehumidifying device, an operating state of a heating device and/or an operating state of a cooling device.

In particular, provision may be made for the pre-defined operating states of the conditioning system to each comprise a pre-defined operating state of a humidification device, a pre-defined operating state of a dehumidifying device, a pre-defined operating state of a heating device and/or a pre-defined operating state of a cooling device.

A pre-defined operating state is, in particular, an operating state which is determined and in particular computed and/or simulated on the basis of the model before carrying out the method for the conditioning of air.

The operating states of the conditioning system selectable on the basis of the model are preferably pre-defined operating states of the conditioning system.

In particular, controlled operation of the conditioning system is implementable by selecting an operating state of the conditioning system on the basis of the model and setting the conditioning system into the selected operating state. The controlled operation of the conditioning system is especially independent of actual values of the at least two parameters of the output air stream of the conditioning system.

Provision may be made for the conditioning system to be set into a readjusting operating state in which a deviation of the actual values of the at least two parameters of the output air stream from the preset target values is determined and in which, for the purposes of further approximation to or equalisation of the actual values with the target values, readjustment of the conditioning system is effected.

A readjustment or a readjusting operating state of the conditioning system is to be understood in particular as being a supplementary regulation of the conditioning system on the basis of the controlled operating state.

In particular, provision may be made for the conditioning system to be set into the readjusting operating state after having been set into the selected operating state wherein a deviation of the actual values of the at least two parameters of the output air stream from the preset target values is determined and wherein, for the purposes of closer approximation to or equalisation of the actual values with the target values, readjustment of the conditioning system is effected.

In particular hereby, provision may be made for the humidification device, the dehumidifying device, the heating device and/or the cooling device to be set into a readjusting operating state.

In one embodiment of the invention, provision may be made for a determination to be made by means of a monitoring device as to whether a deviation of the actual values of the at least two parameters of the output air stream from the preset target values exceeds a preset maximum deviation. In order in particular to enable the proper functioning of the conditioning system to be monitored, the magnitude of the deviations of the actual values of the at least two parameters of the output air stream from the preset target values can preferably be determined.

A malfunction of the conditioning system can preferably be established or determined by means of the monitoring device.

The air that has been conditioned by means of the method according to the invention and in particular the output air stream from the conditioning system can be used in particular in a work-piece processing system.

Consequently, the present invention also relates to a method of supplying air to a work-piece processing system.

The method of supplying air to a work-piece processing system in accordance with the invention preferably comprises particular ones or a plurality of the features and/or advantages described in connection with the method for the conditioning of air in accordance with the invention.

It can be expedient for the output air stream of the conditioning system to be supplied to a processing area of the work-piece processing system in the form of a processing air stream.

Hereby, the plurality of possible actual values of the at least two parameters of the inlet air stream of the conditioning system is preferably linked with the operating states of the conditioning system by means of the model so that the derivable actual values of the at least two parameters of the processing air stream lie within preset target value ranges.

Hereby, the output air stream of the conditioning system can be just a part of a processing air stream or it may form the entire processing air stream for example.

In particular, if the output air stream of the conditioning system is a part of the processing air stream, then the remaining part of the processing air stream can be a circulating air stream that is fed into the work-piece processing system.

If the output air stream of the conditioning system forms the entire processing air stream, then a supply of pure air is preferably provided to the work-piece processing system.

Particularly in the case where the output air stream of the conditioning system forms a part of the processing air stream, provision may be made for the effect of the circulating air stream being fed through an air circulation system on the actual values of the at least two parameters of the processing air stream to be taken into account in the model for the selection of the operating state of the conditioning system.

The model is preferably a model which is specific to the system.

Preferably, the dimensions of the work-piece processing system and in particular the processing area of the work-piece processing system are taken into account in the model.

Furthermore, provision may be made for the type, the extent and/or the duration of the work-piece processing operation that is being carried out by means of the work-piece processing system to be taken into account in the model.

The inlet air stream of the conditioning system can, in particular, be a stream of fresh air or a circulating air stream or a mixture of a stream of fresh air and a circulating air stream.

The method in accordance with the invention is particularly suitable for operating a conditioning system for the conditioning of air.

Consequently, the present invention also relates to a conditioning system for the conditioning of air.

In regard to this aspect, the object of the invention is to provide a conditioning system by means of which air is conditionable in a reliable and energy-efficient manner.

In accordance with the invention, this object is achieved by a conditioning system for the conditioning of air which comprises a control device and a measuring device for determining the actual values of at least two parameters of an inlet air stream of the conditioning system that is to be conditioned,

wherein an operating state of the conditioning system is selectable by means of the control device on the basis of a model by means of which a plurality of possible actual values of the at least two parameters is linked with operating states of the conditioning system, and

wherein the conditioning system is settable into the selected operating state by means of the control device so that an output air stream of the conditioning system is producible in which the actual values of the at least two parameters lie within preset target value ranges.

The conditioning system in accordance with the invention preferably incorporates particular ones or a plurality of the features and/or advantages described above in connection with the methods in accordance with the invention.

The conditioning system preferably comprises a control device for controlling the conditioning system and in particular the implementation of the method in accordance with the invention.

It can be expedient if the control device comprises a memory device in which a parameter map and/or a correlation function is stored, wherein a plurality of possible actual values of the at least two parameters is linked with the operating states of the conditioning system by means of the parameter map and/or by means of the correlation function.

The conditioning system preferably comprises a humidification device, a dehumidifying device, a heating device and/or a cooling device.

In particular the cooling device may simultaneously be a dehumidifying device.

Furthermore, provision may be made for the conditioning system to comprise at least one filter device and/or at least one heat exchanger.

Preferably, heat is transferable from an exhaust air stream leaving a work-piece processing system to the inlet air stream of the conditioning system by means of the heat exchanger.

In one embodiment of the invention, provision is made for the conditioning system to comprise a regulating device by means of which the conditioning system is settable into a readjusting operating state.

In the readjusting operating state, a deviation of the actual values of the at least two parameters of the output air stream from the preset target values is preferably determinable.

Furthermore, readjustment of the conditioning system for the purposes of closer approximation to or equalisation of the actual values with the preset target values is preferably implementable in the readjusting operating state.

Expediently, the conditioning system comprises a monitoring device by means of which it is determinable as to whether a deviation of the actual values of the at least two parameters of the output air stream from the preset target values exceeds a preset maximum deviation.

The conditioning system in accordance with the invention is suitable in particular for use as a component or in combination with a work-piece processing system.

Consequently, the present invention also relates to a work-piece processing system which incorporates a conditioning system in accordance with the invention.

Hereby, the work-piece processing system in accordance with the invention preferably comprises particular ones or a plurality of the features and/or advantages described above in connection with the methods in accordance with the invention and/or the conditioning system in accordance with the invention.

The output air stream of the conditioning system is preferably feedable to a processing area of the work-piece processing system as a processing air stream.

Hereby, the plurality of possible actual values of the at least two parameters of the inlet air stream of the conditioning system is linked with the operating states of the conditioning system by means of the model in such a manner that the derivable actual values of the at least two parameters of the processing air stream lie within preset target value ranges.

The conditioning system can be in the form of an air supply system and/or an air-recirculation system.

To this end, in addition to the humidification device, the dehumidifying device, the heating device and/or the cooling device, the conditioning system preferably comprises a housing, at least one fan (blower), at least one filter device (filter stage), a flow distributor, at least one sound proofing device (muffler) and/or at least one heat conveyer (heat exchanger), in particular, at least one thermal wheel.

Conditioning of air is to be understood in this description and the accompanying Claims in particular as being the processing and/or the treatment of air.

The work-piece processing system is particularly a surface processing system, a machining system, a coating system, a painting system, a drying system and/or a cleaning system.

The work-pieces are vehicles, vehicle parts, vehicle bodies, vehicle attachments, furniture and/or medical instruments for example.

Furthermore, the methods in accordance with the invention and/or the systems in accordance with the invention may incorporate particular ones or a plurality of the features and/or advantages described below:

The conditioning of the air is preferably effected for the purposes of process-security and quality assurance of manufacturing processes especially in the trade and industry fields.

A plurality of process steps are preferably implementable by means of the work-piece processing system and/or in the work-piece processing system especially the cleaning and/or degreasing of work-pieces, formation of a conversion layer on the work-pieces (e.g. phosphating), application of lacquer using a dipping process, application of lacquer using a sputtering or spraying process, baking or hardening the lacquer film, checking the work-pieces and/or re-machining the work-pieces.

In particular when painting work-pieces, the following target value and target value ranges of the relative humidity and the temperature of the processing air stream are preferably used:

When using solvent-based lacquers, the relative humidity preferably amounts to at least approximately 40% and/or at most to approximately 84% and the temperature preferably amounts to at least approximately 20° C. and/or at most approximately 30° C.

When using water-based lacquers, the relative humidity preferably amounts to at least approximately 60% and/or at most approximately 70% and the temperature preferably amounts to at least approximately 20° C. and/or at most approximately 26° C.

When using a single layer water finish coating, the relative humidity preferably amounts to at least approximately 55% and/or at most approximately 75% and the temperature preferably amounts to at least approximately 20° C. and/or at most approximately 26° C.

When using a powder coating particularly powder filler, the relative humidity preferably amounts to at least approximately 40% and/or at most approximately 50% and the temperature preferably amounts to at least approximately 20° C. and/or at most approximately 24° C.

Furthermore, when using a powder coating and especially a powdered clear-lacquer, provision may be made for the relative humidity to amount to at least approximately 40% and/or at most approximately 50% and for the temperature to preferably amount to at least approximately 18° C. and/or at most approximately 22° C.

In individual cases however, such as for reasons of quality for example, provision may also be made for other types of climatic conditions (target values and target value ranges) to be used in dependence on the lacquer system and on the desired colour spectrum.

Provision may be made for the demands on the local air conditioning (conditioning of the processing air stream) in a processing area during the application of water-based lacquers in comparison with the demands on the local air conditioning during the application of solvent-based lacquers to differ and in particular, to be narrower or higher. This, for example, can lie on the water dilutibility and on the special demands being made in regard to quality and appearance such as the reproducible nature and/or uniformity of the effect created in the case of metallic paints or special effect paints for example.

The fresh air supply and the exhaust air requirements of a work-piece processing device in the form of a vehicle paint shop for example for painting 30 car bodies per hour can amount to up to approximately 1.4 million cubic meters per hour for example. The fresh air supply and the exhaust air requirements can preferably be reduced by at least half by reducing the layers of lacquer, the extent of the lacquer and by partial re-circulation of the air within the processing area (spray-booth).

It can be expedient for a large part, at least approximately 50% for example and in particular approximately 80% for example, of the air for conditioning the local region (the processing air stream) to be re-circulated. In particular in the case of a paint shop using a dry deposition process or an electrical deposition process, the air being fed into the air circulation system can be heated up by the frictional heat of the fan (blower) for example. This can preferably be compensated for by means of a cooling device in the conditioning system especially in an air re-circulating system.

In particular for the purposes of removing pollutants, a portion of the circulating air, approximately 20% for example, is preferably removed and supplied to an exhaust air purification system for example. The removed portion of the circulating air is preferably replaced by means of an air supply system, especially a smaller one.

In dependence upon the manufacturing location and the lacquer system being utilised, different demands may be made on the dimensioning and regulation of an air supply system and/or an air re-circulating system.

In the case of very cold locations for example, it is possible to dispense with a cooling device because even in the summer months, high temperatures which would make it necessary for the supplied air to be cooled are not expected.

In the case of a hot humid location in which large variations in temperature and/or humidity fluctuations occur over the whole year for example, a desired conditioning of the air can preferably be effected more easily by means of a cooling device.

However, independently of the location of the conditioning system and/or the work-piece processing system, weather reversals due to the onset of thunderstorms with a resultant rapid rise of the relative air humidity for example can impose great demands on the outlay required for the regulation of the conditioning system. This outlay for the regulation process can preferably be simplified and the conditioning system operated more reliably and more energy-efficiently by the purposeful selection of an operating state of the conditioning system on the basis of a model.

A target value range or the target value ranges of the at least two parameters of the processing air stream is also referred to as a spray booth air conditioning window or as a “Drying Line” for example.

Provision may be made for the target value ranges to comprise individual preferred working points for the winter and the summer for example.

The working points are preferably fixed during the design stage of the conditioning system and/or the work-piece processing system.

Preferably, a process of coordinating the conditioning devices of the conditioning system, especially a humidification device, a dehumidifying device, a heating device and/or a cooling device is effected by means of a global model which takes into account the ambient temperature and the ambient humidity of the conditioning system. The regulation process can preferably be pre-programmed by system parameters.

It can be expedient for the regulation process to be divided into a forward path (pilot control) and a return path (regulation). The pilot control process is preferably effected by selecting the operating state on the basis of the model. The regulation process is preferably the re-adjustment process.

In particular, provision may be made for the pilot control process to compute an energy-optimal correcting variable combination for the conditioning devices of the conditioning system and an optimal target value within a preset target value range based in particular on the model by the solution of an optimisation problem.

Preferably, an optimal solution is computed from the temperature and humidity of the inlet air stream.

It can be expedient if the pilot control signal (a control signal from a control device) by means of which the conditioning system is settable into the selected operating state is supplemented by a regulating signal (re-adjustment; a control signal from a regulating device). The regulating signal is preferably computed using the actual values of the temperature and humidity of the out-flowing air (the output air stream).

A two-degrees of freedom structure can preferably be realized by means of the pilot control process and the regulation process.

In particular in the case where the regulating structure comprises a model of the conditioning system, the controlling strategy for the individual conditioning devices (modules) can preferably be designed in such a way that an energy-optimal operation is immanently impressed for example.

It can be particularly advantageous if the regulation concept for industrial conditioning systems is based on a global model-set for an energy-optimal regulation process.

The adjusting signals (the control signals and/or regulating signals for the setting of the operating states) for the individual conditioning devices are preferably coordinated centrally.

Preferably, changes in strategy can be taken into account in the event of sudden weather reversals for example.

Furthermore, correcting variable combinations as well as target values can preferably be computed in an energy-optimal manner.

The algorithms for the computation strategy are preferably adapted to the process control hardware and/or process control software that are typical of air supply systems and/or air recirculation systems.

In particular hereby, the complex optimisation problem can be reduced to a numerically highly-efficiently solvable linear optimisation problem. The solution of the complex problem is preferably sufficiently precisely approximated by the successive solution of the reduced problem.

Provision may be made for the coordinating regulation process to be pre-programmed by physically interpretable system parameters.

Preferably, substantial cost savings and/or savings of time can be achieved compared with decentralized solutions particularly in regard to the large time constants in air supply systems and/or air re-circulation systems.

Preferably, the danger of oscillation of the conditioning devices and the development of limit cycles can be reduced or in particular, completely prevented.

Preferably, thermodynamic reciprocal effects such as the coupling of temperature and relative humidity for example are taken into account in the model. Preferably thereby, the behaviour of the control system and/or the regulating action can be optimised.

It can be expedient if the controlling behaviour and/or the regulating action of a system especially that of a conditioning system and/or a work-piece processing system can be simulated in advance during the design stage. In particular, an automatic model-based parameter pre-setting process can be effected. Preferably thereby, any deficiencies in the system in regard to the dynamic control, regulating and error-response behaviour can be recognized in advance in an early project phase.

Preferably furthermore, access to a differentiated fault-tracing process can be provided by the use of a model. Actual values of parameters (system parameters) deviating from the expected values can lead to a deviation from a static behaviour in accordance with the model. A changed pattern of behaviour of the regulation process can result therefrom and this can be used for diagnostic purposes.

The preset target value range is preferably the number of working points on a connecting line in the air temperature-air humidity diagram (or enthalpy-humidity diagram) between a summer working point and a winter working point.

Preferably, the ambient temperature and the ambient humidity as well as the connecting line between the summer working point and the winter working point in the air temperature-air humidity diagram are used for the process of computing optimal correcting variables and an optimal target value.

The connecting line can also be referred to as a Drying Line.

The pilot control process preferably enables coordination of the individual conditioning devices based on a model especially a physical one.

For the purposes of optimising the actual values of the at least two parameters of the output air stream that are attainable in the selected operating state of the conditioning system, a re-adjustment process is preferably effected such as by means of an output feedback arrangement for example.

For the realization of the regulation process, provision may preferably be made for known methods of solution such as a decentralized regulator using linear PI regulators for example.

Preferably, the target values of the at least two parameters of the output air stream are computed in order to ensure consistent regulating signals in relation to the control signals.

The correcting variable component of the regulation process is preferably calculated from the difference between the actual values of the at least two parameters of the output air stream and the appertaining target values.

Alternatively or in addition to a decentralized regulation process, provision may also be made for a model-based, linear MIMO regulation process.

The pilot control process and the regulation process together preferably form a coordinating temperature and humidity regulation process.

The conditioning system may preferably be monitored by monitoring the agreement between the system behaviour and a model behaviour, especially a simulated model. A control signal of a control device of the conditioning system then needs to be corrected by means of a regulating device to a lesser extent the more the model behaviour agrees with the system performance.

An incorrectly functioning operating state can preferably be detected by a changed regulating component. In particular, abruptly occurring faults such as a mal-positioned valve for example and/or long-term effects such as wear and tear for example can then be recognized.

In particular, abruptly occurring faults can be directly detected and are diagnosed by warning signals.

Long-term effects can preferably be determined by statistical evaluation of the regulating components.

Further preferred features and/or advantages of the invention form the subject matter of the following description and the graphical illustration of exemplary embodiments.

In the drawings:

FIG. 1 shows a schematic sectional view through a work-piece processing system which comprises a conditioning device for the conditioning of air;

FIG. 2 a schematic sectional view of a further conditioning system;

FIG. 3 a schematic illustration for illustrating the functioning of a conditioning system;

FIG. 4 a schematic illustration for illustrating the control and regulation of a conditioning system;

FIG. 5 a diagram for illustrating the mode of operation of a conditioning system;

FIG. 6 a schematic diagram corresponding to FIG. 5 for illustrating different operational areas of a conditioning system;

FIG. 7 a schematic illustration for illustrating the manner of controlling a conditioning system; and

FIG. 8 a further schematic illustration for illustrating the manner of controlling a conditioning system.

The same or functionally equivalent elements are provided with the same reference symbols in all of the Figures.

A work-piece processing system bearing the general reference 100 which is illustrated in FIG. 1 is in the form of a painting facility 102 for painting work-pieces 103 and in particular vehicle bodies for example.

For this purpose, the work-piece processing system 100 comprises a processing area 104, particularly one in the form of a paint booth 106, and an air feed device 108 by means of which an air stream is caused to pass through the processing area 104.

This air stream is referred to as a processing air stream 109 in the following.

The work-piece processing system 100 comprises a filtering unit 110 by means of which the processing air stream 109 being fed through the processing area 104 is cleanable.

In particular, provision may be made for paint overspray which was picked up by the processing air stream 109 in the processing area 104 to be separable from the processing air stream 109 by means of the filtering unit 110.

The air feed device 108 comprises a conditioning system 114 in the form of an air supply system 112 for example.

Ambient air and in particular fresh air can be sucked in as an inlet air stream 152, conditioned and then supplied e.g. by way of a plenum 116 of the work-piece processing system 100 to the processing area 104 as a processing air stream 109 by means of the conditioning system 114.

The conditioning system 114 comprises an air supply duct 118, a blower 120 for propelling the air stream as well as a plurality of conditioning devices 122.

For example, the conditioning system 114 comprises a conditioning device 122 in the form of a heating device 124, a conditioning device 122 in the form of a cooling device 126, a conditioning device 122 in the form of a humidification device 128 and/or a conditioning device 122 in the form of a dehumidifying device 130.

The air stream being fed through the conditioning system 114 can thus be heated up, cooled, humidified and/or dehumidified by means of the conditioning device 122.

Furthermore, the conditioning system 114 comprises two filter devices 132.

Hereby with respect to a direction of flow 134 of the air stream, a filter device 132 in the form of a pre-filter 136 is arranged upstream of the conditioning devices 122, whilst a filter device 132 in the form of a post-filter 138 is arranged downstream of the conditioning devices 122.

In particular, the conditioning devices 122, the filter devices 132 and the blower 120 are arranged in a housing 150 of the conditioning system 114.

An exhaust air duct 140 of the air feed device 108 serves for removing the processing air stream 109 that has been cleaned by means of the filtering unit 110.

The air supply duct 118 and the exhaust air duct 140 are preferably thermally coupled to one another by means of a heat exchanger 142.

The heat exchanger 142 is in the form of a thermal wheel 144 for example and serves, in particular, for conveying the heat of the air stream being fed through the exhaust air duct 140 (the cleaned processing air stream 109) to the air stream being fed through the air supply duct 118 (the inlet air stream 152).

Finally, the conditioning system 114 also comprises a measuring device 146 by means of which the actual values of at least two parameters of the inlet air stream 152 of the conditioning system 114 being supplied through the air supply duct 118 are determinable.

Optimal control or regulation of the conditioning system 114 and thus of the entire work-piece processing system 100 can be effected on the basis of the actual values that have been determined.

The work-piece processing system 100 illustrated in FIG. 1 functions as follows:

The actual values of at least two parameters of the inlet air stream 152 of the conditioning system 114 are determined by means of the measuring device 146. In particular, the air temperature and the air humidity and in particular, the relative humidity are determined.

On the basis of the actual values of the at least two parameters, the conditioning system 114 is set into a certain operating state in order to deliberately condition the inlet air stream 152 in such a manner that it will have a preset desired air temperature and a preset desired air humidity after it has passed through the conditioning system 114 and thus as it is leaving the system in the form of the output air stream 154 of the conditioning system 114.

The output air stream 154 of the conditioning system 114 is supplied to the processing area 104 as a processing air stream 109.

Due to the fact that the processing air stream 109 exhibits a preset air temperature and a preset air humidity, optimal conditions for the processing of the work-pieces 103 and in particular for painting the work-pieces 103 prevails in the processing area 104.

After flowing through the processing area 104, the processing air stream 109 is cleaned by means of the filtering unit 110 and then expelled through the exhaust air duct 140.

The heat contained in the cleansed processing air stream 109 is at least partly transferred by means of the heat exchanger 142 to the inlet air stream 152 that is being fed through the air supply duct 118 and is thus preferably not expelled unused into the environment of the work-piece processing system 100.

An alternative embodiment of a conditioning system 114 which is illustrated in FIG. 2 basically differs from the embodiment illustrated in FIG. 1 in that the conditioning system 114 comprises two heating devices 124 as well as a sound proofing device 148.

In the case of the conditioning system 114 in accordance with FIG. 2, there is provided a heating device 124 which is in the form of a burner 147 for example.

In relation to the direction of flow 134, the filter device 132 in the form of a pre-filter 136 is arranged downstream of this heating device 124.

Following this filter device 132 in the direction of flow 134, there is the cooling device 126, a heating device 124 in the form of a hot water register, the humidification device 128, the filter device 132 in the form of a post-filter 138 and the blower 120.

The sound proofing device 148 is arranged between the filter device 132 in the form of a post-filter 138 and the blower 120.

In particular, the sound proofing device 148 is arranged to the side on a housing 150 of the conditioning system 114.

An inlet air stream 152 being supplied to the conditioning system 114 can thus firstly be heated up, then cleaned and subsequently cooled, heated up again, humidified and lastly cleaned again by means of the conditioning system 114 illustrated in FIG. 2.

In all other respects, the alternative embodiment of the conditioning system 114 illustrated in FIG. 2 corresponds in regard to the construction and functioning thereof with the conditioning system 114 of the work-piece processing system 100 from FIG. 1, so that to this extent reference should be made to the previous description thereof.

The process of controlling and/or regulating the conditioning system 114 are explained exemplarily hereinafter on the basis of a conditioning system 114 in which a cooling device 126, a heating device 124 and a humidification device 128 are provided in serial succession.

As can be perceived from FIG. 3 in particular, an inlet air stream 152 can be conditioned by means of the conditioning system 114. The conditioned air stream leaves the conditioning system 114 as an output air stream 154.

The cooling device 126 is in the form of a cooling register for example.

The heating device 124 is in the form of a heating register for example.

A variable flow of cooling water is preferably supplied to (not illustrated) register pipes of the cooling device 126 for cooling the air stream being fed through the conditioning system 114.

A variable flow of hot water is preferably supplied to (not illustrated) register pipes of the heating device 124 for heating the air stream being fed through the conditioning system 114.

In particular, the streams of water are preferably controllable and/or regulable by (not illustrated) valves.

The humidification device 128 preferably comprises a controllable and/or regulable humidifier pump 156.

A variable, especially speed-regulated flow of water can be injected into the air stream being fed through the conditioning system 114 by means of the humidifier pump 156.

The flow rate of the air stream being fed through the conditioning system 114 is preferably kept constant by means of a blower 120 (see FIGS. 1 and 2).

As can be perceived in particular from FIG. 3, each conditioning device 122 can preferably be controlled by a separate control signal 158.

In principle therefore, the conditioning devices 122 can be controlled individually and operated substantially independently of each other.

However, as can be perceived from FIG. 4 in particular, the conditioning system 114 preferably has a master control device 160 for controlling the conditioning system 114.

The control device 160 is connected to a measuring device 146 by means of which the actual values of the at least two parameters of the inlet air stream 152 that is to be conditioned are determinable and transmissible to the control device 160 by means of a control or measuring signal 172.

The control device 160 comprises a memory device 162 in which a model 164 or a model-based correlation 164 between a plurality of possible actual values of the at least two parameters of the inlet air stream 152 and the operating states of the conditioning system 114 is stored.

For example, provision may be made for a parameter map 166 and/or a correlation function 168 to be stored by means of the memory device 162.

On the basis of and/or by using the model 164, an operating state of the conditioning system 114 can be selected from the determined actual values of the at least two parameters of the inlet air stream 152 by means of the control device 160.

In order to set the conditioning system 114 into this operating state, one or more control signals 158 are transmitted to the conditioning devices 122 of the conditioning system 114 by means of the control device 160.

Furthermore, the conditioning system 114 may comprise a regulating device 170.

In particular, the regulating device 170 is connected to the control device 160 and also to a measuring device 146 for the purposes of determining the actual values of the at least two parameters of the output air stream 154.

It can then be determined by means of the regulating device 170 as to whether the operating state of the conditioning system 114 selected by means of the control device 160 actually leads to the maintenance of the desired target values of the at least two parameters of the output air stream 154.

Control or measuring signals 172 are exchanged between the measuring devices 146, the control device 160 and the regulating device 170.

As can be perceived in particular from FIG. 4, the control signal 158 that is being supplied to the conditioning devices 122 is an effective control signal 158e which is composed of two control signals 158, namely, a control signal 158s from the control device 160 and a control signal 158r from the regulating device 170.

Preferably thereby, only a slight correction of the control signal 158s from the control device 160 is effected by means of the regulating device 170 since, preferably on the basis of the model 164, an operating state of the conditioning system 114 and in particular that of the conditioning devices 122 which ensures maintenance of the target values of the at least two parameters of the output air stream 154 has already been obtained by means of the control device 160. By monitoring the deviation of the actual values of the at least two parameters of the output air stream 154 from the target values, functional monitoring of the conditioning system 114 can preferably be effected in order to determine malfunctions and disturbances. The regulating device 170 may thus comprise a monitoring device 171.

The control signals 158, 158e, 158s, 158r can, for example, be represented as vectors and in particular as correcting-variable vectors u=[u1 u2 u3]^T. The entries for a correcting-variable vector are preferably the correcting variables of the individual conditioning devices 122.

In particular in the case where the contribution of the regulating device 170 to the effective control signal 158e is small and amounts to less than approximately 20% for example, and in particular less than approximately 10%, provision may be made for the regulating device 170 to be operated using a linear regulation concept.

Based on the model 164, optimal control signals 158 for the cooling device 126, the heating device 124 and the humidification device 128 can be produced by means of the control device 160.

Preferably, an expanded target value range 174 of the at least two parameters, particularly the air temperature and the air humidity can be used.

For example, the target value range 174 is given by the connecting line between two working points 176 in a diagram wherein the air temperature (in ° C.) is plotted against the air humidity (in g water/kg dry air) (see FIG. 5).

The working points 176 are, in particular, a summer working point 176s in which the conditioning system 114 is operable in an energy-efficient manner especially in the summer, and a winter working point 176w in which the conditioning system 114 is operable in an energy-efficient manner especially in the winter.

The summer working point 176s corresponds to an air temperature of approximately 30° C. and a relative humidity of approximately 65% for example.

The winter working point 176w corresponds to an air temperature of approximately 20° C. and a relative humidity of approximately 55% for example.

In dependence on the actual values of the air humidity and the air temperature of the inlet air stream 152, different operating states of the conditioning system 114 have to be realized in order to adhere to the target values, i.e. for the purposes of achieving actual values of the parameters of the output air stream 154 that lie within the target value range 174.

As can be seen on the basis of the point A in FIG. 5 for example, both humidification and heating of the inlet air stream 152 must be effected in the case of very cold and dry air.

In the case of hot dry air (point B), humidification of the inlet air stream 152 may be sufficient for adherence to the target values.

In the case of humid air (point C), provision may be made for the inlet air stream 152 to be cooled and thereby dehumidified, and subsequently for it to be heated (heated-up).

As can be perceived from FIG. 6, there are effectively five different regions, i.e. the regions I to V, which can be distinguished from one another in the air temperature-air humidity diagram.

If the actual values of the inlet air stream 152 result in a point in the region I, then isoenthalpic humidification may be sufficient for adherence to the target values.

In region II, provision may be made for cooling and humidification processes for adherence to the target values.

In region III, cooling together with resultant dehumidification as well as heating of the inlet air stream 152 are preferably effected in order to adhere to the target values.

In region IV, the inlet air stream 152 is preferably merely heated for adherence to the target values.

In region V, both humidification and heating of the inlet air stream 152 is effected in order to adhere to the target values.

In particular, very rapid changes of the actual values of the at least two parameters of the inlet air stream 152 can occur due to changes in the weather.

For example, a change in status from region I to region IV can occur so that the operating state of the conditioning system 114 has to be changed from an isoenthalpic humidification process to a heating process.

With increasing absolute humidity due to the onset of rain for example, a change in the weather from region I to region III can occur for example. Consequently, there has to be a change-over from an isoenthalpic humidification process to a dehumidifying process, in particular, by means of the dehumidifying device 130 and/or by means of the cooling device 126, and also heating by means of the heating device 124.

Such a change-over or switch-over can be accomplished in a particularly simple and reliable manner by means of the model 164.

In FIG. 8, there is illustrated the signal flow of the pilot control process that is implementable by means of the control device 160.

As can be perceived from FIG. 8, the working points 176s, 176w as well as the control or measuring signal 172 from the measuring device 146 are supplied as input variables to the control device 160.

On the basis of the model 164, a check or measuring signal 172 which is passed on to the regulating device 170 as well as the control signal 158s for controlling the conditioning devices 122 are produced by means of the control device 160.

The computation of the control signal 158s from the control device 160 (pilot signal) is preferably effected by the solution of an optimisation problem.

For example, a linear energy function is used as the function that is to be minimized and in particular a cost function and/or quality function:

E(u_d1,u_d2,u_d3,a_d1)=p₁u_d1+p₂u_d2+p₃u_d3+p_d1a_d1  (equation 1).

The variables u_d1, u_d2, and u_d3 are correcting variable components of the pilot control process by virtue of which the energy function E is preferably minimized. The quantity a_d1 preferably indicates the target value within the target value range 174 and in particular within the spray booth air conditioning window (the so-called Drying Line).

The target value is set at the winter working point 176w for a_d1=0 and at the summer working point 176s for a_d1=100. The variables p₁, p₂, p₃ and p_d1 are fixed weighting factors and indicate the linear cost factor of the individual conditioning devices 122.

Equation 1 is preferably minimized using the following auxiliary conditions:

0≦u_d1,u_d2,u_d3,a_d1≦100  (auxiliary condition 1)

and

v_Winter+a_d1v_d1=u_d1v_cool+u_d2v_heat+u_d3v_humidifier   (auxiliary condition 2).

Auxiliary condition 1 preferably ensures that the correcting variables keep the preset boundaries i.e. remain within the preset target value range 174. Auxiliary condition 2 preferably ensures that the solution of the optimisation problem is on the energy-optimal point of the connecting line between the summer working point 176s and the winter working point 176w, i.e. on the Drying Line.

The vectors v_cool, v_heat, and v_humidifier are preferably direction vectors in the enthalpy-humidity diagram. The length and direction of the vectors preferably result from the momentary state of the inlet air stream 152 and the static model behaviour of the conditioning devices 122. The vectors are preferably determined from the model equations of the conditioning system 122.

The direction vector v_Winter preferably describes the vector from the state (working point) of the inlet air stream 122 to the winter working point 176w. The vector v_d1 preferably describes the vector from the winter working point 176w to the summer working point 176s and lies on the Drying Line or runs along the Drying Line. An optimal vector v_res and hence a preferred operating state of the conditioning system 114 can thereby be determined by means of the computed factors a_d1 (see FIG. 7).

The equation 1 and the auxiliary conditions 1 and 2 describe a linear optimisation problem.

The optimisation problem can preferably be solved iteratively by a simplex algorithm in order to match the solution, in particular on-line, to the changing weather conditions. The static solution of the model and thus the optimisation problem preferably alter in the event of a change of the environmental variables.

Optimal operation of the conditioning system 114 can thereby preferably be always ensured by the model-based selection of the operating state.

Claims

1. A method for the conditioning of air, comprising:

determining the actual values of at least two parameters of an inlet air stream of a conditioning system in which the air is to be conditioned;

selecting an operating state of the conditioning system on the basis of a model by means of which a plurality of possible actual values of the at least two parameters is linked to operating states of the conditioning system;

setting the conditioning system into the selected operating state so that an output air stream of the conditioning system is produced in which the actual values of the at least two parameters lie within preset target value ranges.

2. The method in accordance with claim 1, wherein the operating state of the conditioning system is selected on the basis of a parameter map, by means of which a plurality of possible actual values of the at least two parameters is linked with the operating states of the conditioning system.

3. The method in accordance with claim 1, wherein the operating state of the conditioning system is selected on the basis of a correlation function by means of which a plurality of possible actual values of the at least two parameters is linked with the operating states of the conditioning system.

4. The method in accordance with claim 1, wherein one parameter is the air temperature and a further parameter is the air humidity.

5. The method in accordance with claim 1, wherein a plurality of possible actual value combinations of the at least two parameters is linked with a respective operating state of the conditioning system by means of the model.

6. The method in accordance with claim 1, wherein the selectable operating states of the conditioning system are pre-defined operating states of the conditioning system which each comprise a pre-defined operating state of a humidification device, a pre-defined operating state of a dehumidifying device, a pre-defined operating state of a heating device and/or a pre-defined operating state of a cooling device.

7. The method in accordance with claim 1, wherein, after being set into the selected operating state, the conditioning system is set into a readjusting operating state in which a deviation of the actual values of the at least two parameters of the output air stream from the preset target values is determined and in which, for the purposes of further approximation to or equalization of the actual values with the target values, readjustment of the conditioning system is effected.

8. The method in accordance with claim 1, wherein a determination is made by means of a monitoring device as to whether a deviation of the actual values of the at least two parameters of the output air stream from the preset target values exceeds a preset maximum deviation.

9. The method for supplying air to a work-piece processing system comprising a method in accordance with claim 1, wherein the output air stream of the conditioning system is supplied as a processing air stream to a processing area of the work-piece processing system and in

that the plurality of possible actual values of the at least two parameters of the inlet air stream of the conditioning system is linked with the operating states of the conditioning system by means of the model in such a manner that the derivable actual values of the at least two parameters of the processing air stream lie within preset target value ranges.

10. A conditioning system for the conditioning of air comprising a control device and a measuring device for determining the actual values of at least two parameters of an inlet air stream of the conditioning system in which the air is to be conditioned,

wherein an operating state of the conditioning system is selectable by means of the control device on the basis of a model by means of which a plurality of possible actual values of the at least two parameters is linked with operating states of the conditioning system, and

wherein the conditioning system is settable into the selected operating state by means of the control device so that an output air stream of the conditioning system is producible in which the actual values of the at least two parameters lie within preset target value ranges.

11. The conditioning system in accordance with claim 10, wherein the control device comprises a memory device in which a parameter map and/or a correlation function is stored whereby a plurality of possible actual values of the at least two parameters is linked with the operating states of the conditioning system by means of the parameter map and/or by means of the correlation function.

12. The conditioning system in accordance with claim 10, wherein the conditioning system comprises a humidification device, a dehumidifying device, a heating device and/or a cooling device.

13. The conditioning system in accordance with claim 10, wherein the conditioning system comprises a regulating device by means of which the conditioning system is settable into a readjusting operating state in which a deviation of the actual values of the at least two parameters of the output air stream from the preset target values is determinable and in which readjustment of the conditioning system for the purposes of closer approximation to or equalization of the actual values with the preset target values is implementable.

14. The conditioning system in accordance with claim 10, wherein the conditioning system comprises a monitoring device by means of which it is determinable as to whether a deviation of the actual values of the at least two parameters of the output air stream from the preset target values exceeds a preset maximum deviation.

15. A work-piece processing system comprising a conditioning system in accordance with claim 10, wherein the output air stream of the conditioning system is feedable to a processing area of the work-piece processing system as a processing air stream and in that the plurality of possible actual values of the at least two parameters of the inlet air stream of the conditioning system is linked with the operating states of the conditioning system by means of the model in such a manner that the derivable actual values of the at least two parameters of the processing air stream lie within preset target value ranges.