DE10143528A1 - Control device used for a CA generator, comprises a micro-controller for regulating and controlling the conditioning of the atmospheric volume, a human-machine interface for inputting and displaying data, and functional groups - Google Patents

Abstract

Control device (32) comprises: (1) micro-controller (33) for regulating and controlling the conditioning of the atmospheric volume; (2) human-machine interface (34) for inputting and displaying data; (3) functional group (37) for evaluating and determining the measured value; (4) functional group (38) for logging measured data; and (5) functional group (39) for activating generator components. An Independent claim is also included for a process for controlling the temperature and the composition of the goods to be conditioned.

Description

The invention relates to a control device for a CA generator for conditioning one for transportation and / or the storage of perishable goods, such as Food, flowers or the like, created controlled Atmospheric volume, e.g. B. the interior of a Transport containers or trailers.

With the CA generator, the atmosphere volume should pass through a controlled process regarding its composition to be changed. For this it is necessary that the CA- Generator taking into account the nitrogen concentration, the relative humidity, the temperature, the Carbon dioxide concentration and the ethylene concentration in the controlling atmosphere volume is controlled.

The invention has for its object a To create control device for such a CA generator, by means of that with the least possible technical and constructive effort the atmosphere volume always with the if necessary different and changing properties can.

This object is achieved in that the Control device for regulating and a microcontroller Controlling the conditioning of the atmosphere volume Human-machine interface for data entry and display, a function group for the processing of measured values and Measured value acquisition, a function group for logging Measurement data and a function group for activating Has generator components. So it is through human-machine Interface possible, for example, the properties of the Atmosphere volume according to a current need change.

For simple design, it is useful if the Microcontrollers, the human-machine interface and the Function groups combined into an integrated control unit are. As such an integrated control unit Control device according to the invention in a simple manner with a existing CA generator can be combined.

If the integrated control unit is preferably a Communication module equipped with GSM and a GPS link shows, it is possible on the one hand, the respective location the integrated control unit from a control center capture, in addition from this center in the Control device can be intervened, for example for the purpose of changing the controlled atmosphere volume desired properties.

The function group for the processing of measured values and Measured value acquisition is advantageous as measured value preparation and Measured value acquisition module and connected to a downstream one Nitrogen membrane of the CA generator arranged first Oxygen sensor, a downstream of the nitrogen membrane of the CA- Generator arranged first temperature sensor, one in Atmospheric volume arranged second oxygen sensor, one arranged in the atmosphere volume humidity sensor, a in Atmospheric volume arranged second temperature sensor, one arranged in the atmosphere volume carbon dioxide sensor, one differential pressure sensor arranged in the atmosphere volume, one arranged in the atmosphere volume and an ethylene sensor Outside temperature sensor connected. Taking into account the It is measured quantities detected by the sensors mentioned possible to control the atmospheric volume its properties in the given and if necessary to keep changing limit values, the Effort in operating the CA generator kept as low as possible can be.

If the differential pressure sensor by an im Atmospheric volume arranged internal pressure sensor and one outside the Atmospheric volume arranged outside pressure sensor is replaced, can also the absolute pressure level, if necessary, at the conditioning of the atmosphere volume become.

Advantageously, the CA generator and Atmospheric volume arranged gas, humidity and temperature sensors in an integrated EEPROM on your cable connector, in which Correction data for each gas, humidity and temperature sensor are saved.

To influence the respective sensors with each other to prevent it, it is expedient if the gas, temperature, Humidity, differential pressure and outside temperature sensors in Multiplex operation on the data processing and Measured value acquisition module are switched.

The data processing and data acquisition module can via a potential-free serial interface to the Microcontroller be switched on; alternatively it is possible, the processing of measured values and Integrate measured value acquisition module completely into the microcontroller.

According to an advantageous embodiment, the Control device according to the invention on four circuit boards, namely one I / O card on which the microcontroller is arranged Power supply module, a keyboard and display board for the human-machine interface and the processing of measured values and data acquisition module.

To facilitate user guidance, the keyboard and display board for the human-machine interface an advantageous embodiment of the invention Control device a vacuum fluorescent display and Membrane keyboard off.

The keyboard and display board is conveniently over a one-chip controller using an IIC bus with the connected to the I / O card arranged microcontroller.

The microcontroller is expediently pluggable and screwed to the I / O card.

The power supply module is advantageously pluggable with connected to the I / O card.

To control the components of the CA generator are on the I / O card advantageously a 24 V driver output for one Contactor of a compressor motor, a 24 V driver output for a first dryer stage of an adsorption dryer of the CA Generator, one 24 V driver output for a second Drying stage of the adsorption dryer of the CA generator, a 24 V Driver output for a valve, preferably a needle valve, of the CA generator, one 24 V driver output for one Humidifier of the CA generator and a 24 V driver output for a carbon dioxide supply member of the CA generator is formed, which are each connected to the microcontroller.

If the valve of the CA generator is advantageous as Proportional valve is formed, is assigned accordingly 24 V driver output designed for PWM.

According to an advantageous embodiment, the Power supply module on a mains transformer, by means of which one Operating voltage can be reduced from 230 VAc to 24 VAc, after a suitable preparation to supply the 24 V Driver outputs of the I / O card.

To monitor the operation of the electric motor of the Compressor of the CA generator, it is advantageous if the I / O Card a digital input for an overtemperature element, a digital input for one overcurrent element and two digital ones Inputs for two pressure monitoring elements of the electric motor are trained, each to the microcontroller are connected. The one done by the microcontroller Control and regulation of the electric motor of the compressor can thus correct starting behavior of the electric motor, Overcurrent of the electric motor, temperature and pressure monitoring include.

It is advantageous to use a 5 VDC / DC converter Power supply module a galvanically isolated 5 V operating voltage to supply the microcontroller and the keyboard and Display board of the human-machine interface can be generated.

Accordingly, it is advantageous if by means of a 12th VDC / DC converter of the power supply module one galvanic separate 12 V operating voltage to supply the Measured value processing and measured value acquisition module can be generated.

Due to the module design of both the power supply module as well as the I / O card, it is possible to use the inventive Control device with the least possible effort adapt different input voltages.

To interrupt the operation of the control device with It is to be able to determine the least possible effort useful if the microcontroller on the I / O card assigned RTC element is arranged.

Is advantageous as a function group for logging Measurement data provided a data logger on the I / O card arranged and connected to the microcontroller.

A multimedia card can expediently be used as the data logger, preferably a 16 MB multimedia card with SPI bus connection, be provided.

According to an advantageous embodiment of the Control devices according to the invention are stored in the data logger Measurement data via a serial interface with a PC program can be read out and stored as a data file.

It is also advantageous if the I / O card has a has another serial interface for remote monitoring.

By means of the microcontroller of the invention Control device can a control loop for temperature control of the Atmosphere volume and a control loop for the Gas concentration and the humidity of the atmosphere volume are formed, alternatively, however, it is also possible to have a common one Control loop for temperature control, gas concentration and to develop the humidity of the atmosphere volume.

To do that with as little effort as possible controlling atmosphere volumes with regard to the respectively required It is able to change or adapt properties advantageous if in the microcontroller to condition the Atmospheric volume or the interior of the transport container an adjustable upper temperature limit, a adjustable lower temperature limit, an adjustable upper Oxygen limit, an adjustable lower Oxygen limit, an adjustable upper humidity limit adjustable lower humidity limit, an adjustable upper carbon dioxide limit, an adjustable lower Carbon dioxide limit and an adjustable upper Ethylene limit value can be saved.

The control device is expediently designed such that that it generates an error message and is forwardable. Such an error message can all for the Control or regulation of the atmosphere volume acting Concern components.

The communication module of the control device is expediently equipped for TCP / IP data transmission, whereby advantageous measuring and other related to the atmosphere volume Data including error messages continuously or can be placed discontinuously on the Internet. So with comparatively low means a continuous Monitoring of the atmosphere volume by one with one Control management can be placed anywhere.

In a method according to the invention for controlling the Temperature and the composition of one for transportation and / or the storage of perishable goods, such as Food, flowers or the like, created controlled Atmospheric volume, e.g. B. the interior of a transport container or trailers, the atmosphere volume is cooled or warms when its temperature has an upper temperature limit exceeds or falls below a lower temperature limit, becomes when the oxygen content of the atmosphere volume unites exceeds the upper oxygen limit, a nitrogen flow introduced into the atmosphere volume until the Oxygen content of the atmosphere volume has a lower oxygen limit is reached when the oxygen content of the Atmosphere volume reached the lower limit, checked whether the relative Humidity of the atmosphere volume above or below one upper humidity limit value, if the relative Humidity of the atmosphere volume above the upper one Moisture limit value is a dry, containing oxygen Gas flow introduced into the atmosphere volume until either the relative humidity of the atmosphere volume the upper Humidity limit or the oxygen content of the Atmosphere volume reaches the upper oxygen limit, where, if the upper oxygen limit is reached before the below the upper humidity limit value purer nitrogen stream introduced into the atmosphere volume , and this alternating introduction of a dry, oxygen-containing gas stream and a purer Nitrogen flow is continued until both the relative humidity of the atmosphere volume below the upper one Moisture limit value is as well as the oxygen content of the Atmospheric volume between the upper and lower Oxygen limit is.

In an advantageous embodiment of the invention Process is the carbon dioxide content of the atmosphere volume between an upper and a lower carbon dioxide limit held in the case of falling below the lower Carbon dioxide limit carbon dioxide introduced into the atmosphere volume and if the upper limit of carbon dioxide is exceeded Carbon dioxide content by adding an oxygen-containing Gas flow or a nitrogen flow into the Atmospheric volume reduced to the ambient carbon dioxide concentration becomes.

According to a further advantageous embodiment of the inventive method, the ethylene content of Atmosphere volume kept below an upper ethylene limit, in which when the upper ethylene limit is exceeded Oxygen containing gas stream or a nitrogen stream in the atmosphere volume is introduced until the ethylene content of the atmosphere volume below the upper ethylene limit lies.

In an advantageous development of the invention The procedure is the relative humidity of the atmosphere volume kept above a lower humidity limit, in which at Water is atomized below the lower moisture limit and is introduced into the atmosphere volume until the relative humidity of the atmosphere volume above the lower one Moisture limit value.

In the following, the invention is illustrated by an embodiment explained in more detail with reference to the drawing.

Show it:

... Figure 1 shows an embodiment of a vehicle equipped with an inventive control device CA generator for conditioning a for the transport and / or storage of perishable goods, such as foods, flowers or the like, controlled atmosphere created volume;

Fig. 2 is a schematic diagram of the control device according to the invention; and

Fig. 3 is an overview of essential elements of the control device according to the invention.

An embodiment of a CA-generator 1 for conditioning a controlled atmosphere volume 2 shown in Fig. 1 is used for example for conditioning the atmosphere volume or interior space 2 within a reefer refrigerated container 3, the od transport food. Like. Is used. The reefer reefer container 3 can be equipped with a circulating air fan 4 and with a pressure relief valve 5 .

The CA generator 1 for conditioning the atmosphere volume 2 within the reefer reefer container 3 includes a compressor 6 , a compressed air treatment device 7 , a moisture control device 8 and a carbon dioxide supply element 9 .

The compressor 6 is driven by an electric motor 10 which is connected to an electrical power source via a phase correction element 11 .

Control elements of the compressed air treatment device 7 , the humidity control device 8 and the carbon dioxide supply element 9 are electrically connected via a mains transformer or voltage converter 12 .

The compressor 6 is equipped with an overtemperature element 13 , an overcurrent element 14 and two pressure monitoring elements 15 , 16 .

Ambient air is compressed by means of the compressor 6 . The condensate resulting from this compression process is separated from the resulting compressed air in a cyclone separator 17 which is arranged downstream of the compressor 6 and belongs to the compressed air treatment device 7 and is fed to an automatic condensate drain 18 assigned to the cyclone separator 17 . The condensate obtained during the compression process is usually composed essentially of water.

Downstream of the cyclone separator 17 , a microfilter 19 is provided in the compressed air treatment device 7 . In this downstream microfilter 19, the compressed air is cleaned, whereby the micro-filter 19 has a configuration can be deposited by means of the particles from the compressed air, the greater than 0.01 are .mu.m, and by means of the 19 downstream of the microfilter, a residual oil aerosol content of less than 0.01 mg / m ³ (PPM) according to DIN / ISO 8573-1 can be guaranteed.

The substances separated from the compressed air in the microfilter 19 likewise get into an automatic condensate drain 20 .

After the compressed air has flowed through the microfilter 19 , it gets into an adsorption dryer 21 . The adsorption dryer 21 is designed in two stages. In it, further water or further condensates are removed from the compressed air flow by granulate suction. The two stages of the adsorption dryer 21 alternately absorb water or are dried themselves. Due to the drying principle used in the adsorption dryer 21 , a pressure dew point (DTP) of -40 degrees C can be achieved there.

Downstream of the adsorption dryer 21 , a nitrogen membrane 22 is arranged in the compressed air treatment device 7 , in which the nitrogen content of the compressed air coming from the adsorption dryer 21 into the nitrogen membrane 22 is enriched.

Due to the pressure dew point of the compressed air of -40 degrees C in the adsorption dryer 21 , it is achieved that in the nitrogen membrane 22 condensate can only precipitate below a temperature of -40 degrees C, which could lead to the destruction of the nitrogen membrane 22 . The pressure dew point that can be achieved by means of the adsorption dryer 21 thus enables a long service life of the nitrogen membrane 22 .

In addition to its own temperature, the nitrogen membrane 22 arranged downstream of the adsorption dryer 21 has reached an optimal operating point when the gas mixture flowing through it or the compressed air has a constant pressure. If operational pressure fluctuations occur, the efficiency of the nitrogen membrane 22 , in the gas membrane module or molecular filter of which nitrogen is obtained, ie its ability to generate nitrogen in sufficient quantities, is drastically reduced.

In order to avoid such pressure fluctuations, a pressure holding valve 23 is provided downstream of the nitrogen membrane 22 within the compressed air treatment device 7 . The system pressure is obtained from the compressor 6 via the cyclone separator 17 , the microfilter 19 , the adsorption dryer 21 and the nitrogen membrane 22 by means of this pressure maintaining valve 23 . The compressor 6 and the cyclone separator 17 , the microfilter 19 , the adsorption dryer 21 and the nitrogen membrane 22 of the compressed air treatment device 7 thus constitute a subsystem which is delimited from the overall arrangement of the CA generator 1 by means of the pressure maintaining valve 23 .

If the pre-set operating pressure of the overall arrangement of the CA generator 1 falls below due to a fault downstream of the pressure-maintaining valve 23 , the flow of compressed air is interrupted, so that there is no pressure drop in the nitrogen membrane 22 , as a result of which the residual oxygen concentration in the nitrogen membrane 22 could fluctuate in an undesired manner , The fluctuation of this residual oxygen concentration is highly undesirable, since this residual oxygen concentration is very important to create or maintain the controlled atmospheric conditions in the atmosphere volume 2 of the reefer reefer container 3 , in which, for example, the food can be stored.

The humidity control device 8 is used to adjust the relative humidity of the gas forming the controlled atmosphere volume 2 within the reefer reefer container 3 . This relative humidity is, for example, the reason why z. B. mold or the like on food stored or transported in the reefer refrigerated container 3 or the like. Or not.

To set this relative humidity, the humidity control device 8 has a dehumidifying device 24 and a humidifying element 25 .

The dehumidifying device 24 has an electro-pneumatic needle valve 26 which is arranged downstream of the pressure-maintaining valve 23 and by means of which the flow of the gas leaving the nitrogen membrane 22 can be regulated. In this way, the degree of purity of the dry nitrogen gas mixture leaving the nitrogen membrane 22 can be regulated.

The moistening member 25 has a solenoid valve 27 which is connected on the input side to the automatic condensate drain 18 assigned to the cyclone separator 17 . The separated and filtered water present there and directed to the solenoid valve 27 is sprayed through the solenoid valve 27, depending on the humidification requirement of the controlled atmosphere volume 2 in the reefer cooling container 3, with operating pressure via a nozzle 28 into the reefer cooling container 3 .

If humidification of the interior 2 of the reefer reefer container 3 is not required, the excess water is released to the environment via a drain 29 from the solenoid valve 27 .

The serving for regulating the carbon dioxide content of the atmosphere volume 2 within the reefer reefer container 3 carbon dioxide supply member 9 has a carbon dioxide reservoir 30 , z. B. a bottle from which or the carbon dioxide can be introduced via a controllable valve 31 into the interior or the atmosphere volume 2 of the reefer reefer container 3 . The amount of carbon dioxide available for the carbon dioxide regulation of the atmosphere volume 2 is limited. To increase the carbon dioxide content in the atmosphere volume 2 , carbon dioxide is supplied, the carbon dioxide content of the atmosphere volume 2 being reduced to the carbon dioxide concentration in the ambient air by flushing the interior 2 of the reefer refrigerated container with a nitrogen or oxygen-enriched nitrogen stream.

If the ethylene content is intended for the atmosphere volume 2, a control, these ethylene scheme is limited to a reduction in ethylene concentration in the atmosphere by volume. 2 In the event that the ethylene concentration in the atmosphere volume 2 rises above an upper ethylene limit value, the interior or the atmosphere volume 2 of the reefer reefer container 3 is flushed with a nitrogen or an oxygen-enriched nitrogen stream, whereby the ethylene content is reduced to the ethylene concentration of the ambient air can be.

The CA generator described above with reference to FIG. 1 is used to produce the desired climate for the atmosphere volume 2 or in the interior 2 of the reefer reefer container 3 . For this purpose, the compressor 6 draws in natural ambient air, which is cleaned in the compressed air treatment device 7 and pressed through the nitrogen membrane 22 ; by means of this nitrogen membrane 22 , oxygen and nitrogen are separated from one another. The nitrogen obtained in the nitrogen membrane 22 is introduced into the interior 2 of the reefer reefer container 3 .

In the manner described above, it is possible to enrich the nitrogen content in the interior 2 of the reefer reefer container 3 up to 99%. Since the nitrogen content itself can only be measured in a very complex manner, the measured quantities for determining the nitrogen content are the residual oxygen, the carbon dioxide and the ethylene content.

Furthermore, in the course of the air conditioning of the interior 2 of the reefer refrigerated container 3, the interior 2 is cooled and the relative humidity or humidity in the interior 2 is regulated. Due to the CA generator 1 provided for the above-described conditioning of the climate inside the interior 2 , an overpressure is generated in the interior 2 of the reefer refrigerated container 3 .

A control device 32 of the CA generator 1 , shown in principle in FIG. 1 and explained in more detail with reference to FIGS . 2 and 3, must therefore regulate or regulate the parameters listed below, by which the atmosphere volume 2 within the reefer refrigerated container 3 can control:
The nitrogen content or the nitrogen concentration, the regulation of which takes place via the regulation of the more measurable residual oxygen content or the residual oxygen concentration;
the relative humidity or humidity;
the temperature;
the carbon dioxide content or the carbon dioxide concentration - in regulation limited by regulation - and
the ethylene content or the ethylene concentration.

In principle, it is also or additionally possible to use the CH4 Regulate content or the CH4 concentration, namely in similarly as in the case of the regulation of the Carbon dioxide content or the carbon dioxide concentration.

The parameters listed above must be coordinated controllable and controllable on each other and independently of each other his.

To implement the above-described control and regulation processes, the control device 32 described in more detail below with reference to FIGS. 2 and 3 for the CA generator 1 shown in FIG. 1 has a microcontroller system or a microcontroller 33 for regulating and controlling the processes running in the CA generator 1 , a human-machine interface 34 with a data input 35 and a data display 36 , a function group for processing and recording measured values 37, a function group for logging measurement data 38 , to which a communication module 39 is assigned, and a function group 40 serving to activate generator components.

The control device 32 according to the invention is shown as an integrated control unit 32 in a schematic representation in FIG. 2. The individual functions of the integrated control unit 32 explained above can in principle also be implemented separately.

A large number of sensors are assigned to the functional group for measured value processing and measured value acquisition 37 , of which a moisture, a carbon dioxide and an oxygen sensor are shown by way of example in FIG. 2.

The communication module 39 assigned to the function group for logging measurement data 38 is provided with a GSM link 41 and a GPS link 42 . By means of the communication module 39, it is possible to determine the position of the control device or integrated control unit 32 and thus of the reefer reefer container 3, as well as communication with a control center or the like.

The data input 35 and the data display 36 make it possible for an operator 43 to intervene in the control device or the integrated control unit 32 via the human-machine interface 34 .

By means of the function group 40 which serves to activate generator components, the control and regulation of the electric motor 10 of the compressor 6 of the CA generator 1 and further components of the CA generator 1 shown in FIG. 1 are possible.

The functional group for the measurement value preparation and measurement value acquisition 37 is designed in a modular manner in the exemplary embodiment shown, as can be seen in particular from FIG. 3. The microcontroller 33 is provided in the form of a microcontroller module that can be plugged and screwed onto an I / O card. A power supply module 45 is connected to the I / O card 44 .

The compressor 6 required for the operation of the CA generator 1 is controlled, regulated and monitored by the microcontroller 33 . For this purpose, the microcontroller 33 is connected to the overtemperature element 13 , the overcurrent element 14 and the pressure monitoring elements 15 , 16 of the compressor 6 via digital inputs 46 , 47 , 48 , 49 provided on the I / O card 44 . The control and regulation function exercised by the microcontroller 33 with regard to the compressor 6 or its electric motor 10 thus comprises, on the one hand, the correct starting behavior of the electric motor 10 of the compressor 6 , overcurrent monitoring, temperature monitoring and pressure monitoring.

For any additional monitoring elements or the like to be connected, the I / O card 44 has two further digital inputs 50 , 51 as a reserve.

As shown in principle there, the measured value processing and acquisition module 37 shown in FIG. 2 is a second oxygen sensor 54 to a first oxygen sensor 52 and to a first temperature sensor 53 , both of which are arranged downstream of the nitrogen membrane 22 within the CA generator 1 , a humidity sensor 55 , a second temperature sensor 56 , a carbon dioxide sensor 57 , a differential pressure sensor 58 and an ethylene sensor, not shown, which are arranged in the interior 2 of the reefer reefer container 3 , and connected to an outside temperature sensor 59 .

The sensors 52 to 59 mentioned above each have an EEPROM integrated in their supply connector, in which correction data for each individual sensor 52 to 59 are stored.

The detection of the measured values of the sensors 52 to 59 is integrated in the control device 32 . Correspondingly, the correction values must be read from the EEPROM of sensors 52 to 59 and included in the calculation of the measured values. In order to avoid mutual interference between the sensors 52 to 59 , it is necessary that they are potential-free to one another. This is achieved by means of a multiplex operation which switches only the sensor 52 , 53 , 54 , 55 , 56 , 57 , 58 and 59 to be evaluated to the measured value processing and acquisition module 37, while all other sensors 52 to 59 remain unconnected.

The connection of the measured value processing and measured value acquisition module 37 to the I / O card 44 or the microcontroller 33 can, as shown in FIG. 3, be implemented via a potential-free serial interface 60 ; in principle, however, it is also possible to fully integrate the measured value processing and measured value acquisition module 37 into the microcontroller system.

The control device according to the invention, which has the microcontroller 33 as the core element, controls or regulates the functions of the data input 35 and the data display 36 of the human-machine interface (MMI) 34 , the electric motor 10 of the compressor 6 , and the atmospheric conditions in the interior 2 of the reefer refrigerated container 3 , an RTC (Real-Time-Clock) element 61 , monitoring functions and the function group for logging measurement data 38 .

In the embodiment of the control device 32 shown in FIG. 3, it has four printed circuit boards, namely the I / O card 44 with the microcontroller 33 , the power supply module 45 , a keyboard and display board 62 for the data input 35 and the data display 36 of the human operator. Machine interfaces 34 and the measured value processing and measured value acquisition module 37 .

The keyboard and display board 62 realizes the data input 35 for entering parameters and the data display 36 for measured values. To facilitate or ensure the operator guidance, the data display 36 is designed as a vacuum fluorescent display and the data input 35 as a membrane keyboard.

The connections of the data display 36 and the data input 35 are routed to the keyboard and display board 62 . The connection to the microcontroller 33 arranged on the I / O card 44 is established via a single-chip controller by means of a serial IIC bus 63 . From there, the keyboard and display board 62 is supplied with a 5 V operating voltage.

As already mentioned, the regulation and control of the conditioning process carried out by means of the CA generator 1 are carried out by means of the microcontroller 33 , which is designed in a modular manner and is pluggable and screwable on the I / O card 44 . For this purpose, the I / O card 44 has driver outputs connected to the microcontroller 33 , namely a 24 V driver output 64 for the control of a contactor 65 of the electric motor 10 of the compressor 6 , and a 24 V driver output 66 for the control of a contactor 67 first stage of the adsorption dryer 21 , a 24 V driver output 68 for the control of a contactor 69 of the second dryer stage of the adsorption dryer 21 , a 24 V driver output 70 for the control of the needle valve 26 , a 24 V driver output 71 for the control of the humidifying element 25 and a 24 V driver output 72 for driving the carbon dioxide supply element 9 .

For any further controls, two 24 V driver outputs 73 , 74 are provided on the I / O card 44 as a reserve.

The power supply module 45 is immediately connected to the I / O card 44 and has a power transformer 75, by means of which the 230 VAC operating voltage at 24 VAc down is transformed. After appropriate preparation, this 24 VAc voltage is used to supply the contactors connected to the I / O card 44 . The galvanically isolated operating voltages for the microcontroller 33 and the measured value processing and measured value acquisition module 37 are generated therefrom via 5 V and 12 V DC / DC converters. The modular structure makes it possible to adapt the control device 32 more easily to other input voltages.

The externally mounted contactors 65 , 67 , 69 are controlled via the 24 V driver outputs designed as transistor drivers.

For monitoring purposes, the control device 32 has a data logger 76 , the function of which starts automatically after the operating voltage is applied to the control device 32 .

The data are the date, the time, the temperature, the oxygen concentration, the relative humidity, the carbon dioxide concentration and the ethylene concentration, in each case in the interior 2 of the reefer reefer container 3 , and the upper temperature limit value, lower temperature limit value, upper one specified at the respective time Oxygen limit value, lower oxygen limit value, upper moisture limit value, lower moisture limit value, upper carbon dioxide limit value, lower carbon dioxide limit value and upper ethylene limit value and, moreover, the operating state of the CA generator 1 is detected.

The corresponding data are stored, for example, at least every 15 minutes or if one of the limit values is exceeded or fallen below. This log function cannot be switched off. The data mentioned are written into a ring buffer. If the power supply to the reefer reefer container 3 is interrupted, this can be determined on the basis of a time / date gap in the log, since the RTC element 61 integrated in the control device 32 continues to run.

The ring buffer or memory of the data logger 76 is designed such that data can be stored over a continuous period of at least 180 days, for example. This data can be read out via a serial interface 77 of the I / O card assigned to the data logger 76 using a PC program and stored as a data file.

A 16 MB multimedia card 78 with an SPI bus connection is used to store this amount of data in the data logger 76 because of the limited address space of the microcontroller 33 .

For remote monitoring, the I / O card has a further serial interface 79 .

Furthermore, in the embodiment of the I / O card 44 shown in FIG. 3, a serial interface 80 is also provided as a reserve.

In the embodiment of the control device 32 according to the invention shown by way of example in FIGS. 2 and 3, two separate control loops are provided, namely a control loop for the temperature control and a control loop for the control of the gas concentrations and the humidity in the atmosphere volume 2 . In principle, however, it is also possible to integrate the two control loops into a common multivariable control.

The temperature control is, for example, with a Standard cooling unit implemented.

When the reefer refrigerated container 3 is loaded, there is an oxygen content of approximately 20.9% in the interior 2 thereof. This oxygen content is detected by the second oxygen sensor 54 arranged in the interior 2 and passed on to the microcontroller 33 via the measured value evaluation and measured value acquisition module 37 . There it is found that the oxygen content in the interior 2 has exceeded the upper oxygen limit.

In response to this determination, the compressor 6 of the CA generator 1 is switched on by the microcontroller 33 , the CA generator being switched to nitrogen injection, that is to say the gas stream directed into the interior 2 of the reefer refrigerated container 3 is passed over the nitrogen membrane 22 .

If at the same time the temperature control or cooling is switched on, it must be taken into account that this alone the value of the relative humidity increases. During the Nitrogen blowing can therefore occur that the value of the relative humidity rises above 99%. Initially this has none Consequences.

When the oxygen content in the interior 2 of the reefer cooling container 3 reaches the lower oxygen limit value, the controller or the microcontroller 33 checks whether the relative humidity detected by the moisture sensor 55 in the interior 2 of the reefer cooling container 3 is still above the upper moisture limit value. If this is the case, it is necessary for a dry gas mixture to continue to be blown into the interior 2 . However, since the lower oxygen limit has already been reached, an enriched dry oxygen mixture is now blown in. If the upper oxygen limit value in the interior 2 is exceeded again as a result of this injection, the CA generator 1 is again set such that a purer nitrogen mixture is blown into the interior 2 . This process sequence continues until both the relative humidity falls below the upper humidity limit value and the oxygen content in the interior 2 lies between the upper and the lower oxygen limit value.

The carbon dioxide used for carbon dioxide control is removed from the carbon dioxide storage container 30 ; it is limited in quantity. The carbon dioxide content in the interior 2 is detected by means of the carbon dioxide sensor 57 and passed on to the microcontroller 33 via the measured value processing and measured value acquisition module 37 . If the carbon dioxide content is above the upper carbon dioxide limit value, the interior 2 is flushed with a nitrogen or oxygen mixture until the carbon dioxide content within the interior 2 is reduced to the carbon dioxide concentration in the vicinity of the reefer reefer container 3 . If the detected carbon dioxide content in the interior 2 is below the lower carbon dioxide limit value, carbon dioxide is introduced from the carbon dioxide storage container 30 into the interior 2 by means of the carbon dioxide supply member 9 until the carbon dioxide content assumes acceptable values.

The regulation of the ethylene content within the interior 2 is limited to a reduction in the ethylene content in the interior 2 . In the event that the ethylene sensor forwards an ethylene content via the measured value evaluation and measured value acquisition module 37 to the microcontroller 33 which is above the upper ethylene limit value, the interior 2 is flushed with a nitrogen or oxygen mixture, as a result of which the ethylene content is reduced there.

If the relative humidity in the interior 2 falls below the lower moisture limit value, water is atomized by means of the humidification element 25 and sprayed into the interior 2 .

Claims (36)

1. Control device for a CA generator ( 1 ) for conditioning a for the transport and / or storage of perishable goods, such as food, flowers or the like, created controlled atmosphere volume ( 2 ), z. B. the interior ( 2 ) of a transport container ( 3 ) or trailer, characterized in that the control device ( 32 ) a microcontroller ( 33 ) for regulating and controlling the conditioning of the atmosphere volume ( 2 ), a human-machine interface ( 34 ) for data input and display, a function group for measurement value preparation and measurement value acquisition ( 37 ), a function group for logging measurement data ( 38 ) and a function group ( 39 ) for activating generator components ( 6 , 7 , 8 , 9 ). 2. Control device according to claim 1, in which the microcontroller ( 33 ), the human-machine interface ( 34 ) and the functional groups ( 37 , 38 , 40 ) are combined to form an integrated control unit ( 32 ). 3. Control device according to claim 2, the integrated control unit ( 32 ) of which has a communication module ( 39 ). 4. Control device according to claim 3, in which the communication module ( 39 ) is assigned a GSM ( 41 ) and a GPS link ( 42 ). 5. Control device according to one of claims 1 to 4, whose functional group for measured value preparation and measurement value acquisition ( 37 ) is designed as a measurement value preparation and measurement value acquisition module ( 37 ) and is arranged on a first oxygen sensor ( 52 ) arranged downstream of a nitrogen membrane ( 22 ) of the CA generator ( 1 ) ), a downstream of the nitrogen membrane (22) of the CA-generator (1) arranged first temperature sensor (53), an arranged in atmosphere volume (2) the second oxygen sensor (54), an arranged in atmosphere volume (2) moisture sensor (55), one in the atmosphere volume connected (2) arranged second temperature sensor (56), an arranged in atmosphere volume (2) carbon dioxide sensor (57), an arranged in atmosphere volume (2) differential pressure sensor (58), one in the atmosphere volume (2) arranged ethylene sensor and an outdoor temperature sensor (59) is. 6. Control device according to claim 5, in which the differential pressure sensor ( 58 ) is replaced by an internal pressure sensor arranged in the atmosphere volume ( 2 ) and an external pressure sensor arranged outside the atmosphere volume ( 2 ). 7. Control device according to claim 5 or 6, wherein the in the CA generator ( 1 ) and in the atmosphere volume ( 2 ) arranged gas ( 52 , 54 , 57 ), humidity ( 55 ) and temperature sensors ( 53 , 56 ) in their Supply plugs have an integrated EEPROM in which correction data of each gas ( 52 , 54 , 57 ), humidity ( 55 ) and temperature sensor ( 53 , 56 ) are stored. 8. Control device according to one of claims 5 to 7, wherein the gas ( 52 , 54 , 57 ), temperature ( 53 , 56 ), humidity ( 55 ), differential pressure ( 58 ) or internal pressure and external pressure and outside temperature sensors ( 59 ) are connected in multiplex mode to the measured value processing and measured value acquisition module ( 37 ). 9. Control device according to one of claims 5 to 8, wherein the Messwertaufbereitungs- and data acquisition module (37) is connected to the microcontroller (33) by means of a potential-free serial port (60). 10. Control device according to one of claims 5 to 8, in which the measured value processing and measured value acquisition module ( 37 ) is completely integrated into the microcontroller ( 33 ). 11. Control device according to one of claims 5 to 10, an I / O card ( 44 ) on which the microcontroller ( 33 ) is arranged, a power supply module ( 45 ), a keyboard and display board ( 62 ) for human Machine interface ( 34 ) and the measured value processing and measured value acquisition module ( 37 ). 12. Control device according to claim 11, wherein the keyboard and display board ( 62 ) for the human-machine interface ( 34 ) forms a vacuum fluorescent display ( 36 ) and a membrane keyboard ( 35 ) for the operator guidance. 13. Control device according to claim 11 or 12, wherein the keyboard and display board ( 62 ) is connected via a single-chip controller by means of an IIC bus ( 63 ) to the microcontroller ( 33 ) arranged on the I / O card ( 44 ). 14. Control device according to one of claims 11 to 13, wherein the microcontroller ( 33 ) can be plugged and screwed to the I / O card ( 44 ). 15. Control device according to one of claims 11 to 14, wherein the power supply module ( 45 ) is pluggably connected to the I / O card ( 44 ). 16. Control device according to one of claims 11 to 15, in which on the I / O card ( 44 ) a 24 V driver output ( 64 ) for a contactor ( 65 ) of a compressor motor ( 10 ), a 24 V driver output ( 66 ) for a first dryer stage of an adsorption dryer ( 21 ) of the CA generator ( 1 ), a 24 V driver output ( 68 ) for a second dryer stage of the adsorption dryer ( 21 ) of the CA generator ( 1 ), a 24 V driver output ( 70 ) for a valve, preferably a needle valve ( 26 ) of the CA generator ( 1 ), a 24 V driver output ( 71 ) for a humidification element ( 25 ) of the CA generator ( 1 ) and a 24 V driver output ( 72 ) for a carbon dioxide supply member ( 9 ) of the CA generator ( 1 ) are formed, which are connected to the microcontroller ( 33 ). 17. Control device according to claim 16, wherein the valve of the CA generator ( 1 ) as a proportional valve and the 24 V driver output ( 70 ) are designed PWM-capable. 18. Control device according to one of claims 11 to 17, in which by means of a mains transformer ( 75 ) of the power supply module ( 45 ) an operating voltage from 230 VAc to 24 VAc can be transformed down, which is suitably prepared for supplying the 24 V driver outputs ( 64 , 66 , 68 , 70 to 74 ) of the I / O card ( 44 ) is used. 19. Control device according to one of claims 11 to 18, in which on the I / O card ( 44 ) a digital input ( 46 ) for an overtemperature element ( 13 ), a digital input ( 47 ) for an overcurrent element ( 14 ) and two digital inputs ( 48 , 49 ) for two pressure monitoring elements ( 15 , 16 ) of a compressor ( 6 ) of the CA generator ( 1 ) are formed, which are connected to the microcontroller ( 33 ). 20. Control device according to one of claims 11 to 19, in which by means of a 5 V DC / DC converter of the power supply module ( 45 ) a galvanically isolated 5 V operating voltage for supplying the microcontroller ( 33 ) and the keyboard and display board ( 62 ) of the human-machine interface ( 34 ) can be generated. 21. Control device according to one of claims 11 to 20, in which by means of a 12 V DC / DC converter of the power supply module ( 45 ) a galvanically isolated 12 V operating voltage for supplying the measured value processing and measured value acquisition module ( 37 ) can be generated. 22. Control device according to one of claims 11 to 21, in which an RTC element ( 61 ) assigned to the microcontroller ( 33 ) is arranged on the I / O card ( 44 ). 23. Control device according to one of claims 11 to 22, in which a data logger ( 76 ) is provided as a function group for logging measurement data, which is arranged on the I / O card and connected to the microcontroller ( 33 ). 24. Control device according to claim 23, in which a multimedia card ( 78 ), preferably a 16 MB multimedia card, with an SPI bus connection is provided as the data logger ( 76 ). 25. Control device according to claim 23 or 24, in which the measurement data stored in the data logger ( 76 ) can be read out via a serial interface ( 77 ) with a PC program and stored as a data file. 26. Control device according to one of claims 11 to 25, wherein the I / O card has a further serial interface ( 79 ) for remote monitoring. 27. Control device according to one of claims 1 to 26, by means of whose microcontroller ( 33 ) a control loop for the temperature control of the atmosphere volume ( 2 ) and a control loop for the gas concentration and the humidity of the atmosphere volume ( 2 ) are formed. 28. Control device according to one of claims 1 to 26, by means of whose microcontroller ( 33 ) a common control circuit for the temperature control, the gas concentration and the humidity of the atmosphere volume ( 2 ) is formed. 29. Control device according to one of claims 1 to 28, in which in the microcontroller ( 33 ) for conditioning the atmosphere volume ( 2 ) or the interior ( 2 ) of the transport container, an adjustable upper temperature limit, an adjustable lower temperature limit, an adjustable upper oxygen limit adjustable lower oxygen limit value, an adjustable upper humidity limit value, an adjustable lower humidity limit value, an adjustable upper carbon dioxide limit value, an adjustable lower carbon dioxide limit value and an adjustable upper ethylene limit value can be stored. 30. Control device according to one of claims 1 to 29, by means of which an error message can be generated and forwarded is. 31. Control device according to one of claims 3 to 30, whose communication module ( 39 ) is equipped for TCP / IP data transmission. 32. Control device according to claim 31, by means of whose communication module ( 39 ) the atmospheric volume ( 2 ) relating to measurement or other data including error messages can be placed continuously or discontinuously on the Internet. 33. A method for controlling the temperature and the composition of a controlled atmosphere volume ( 2 ), e.g., for the transport and / or storage of perishable goods, such as food, flowers or the like. B. the interior ( 2 ) of a transport container ( 3 ) or trailer, in which the atmosphere volume ( 2 ) is cooled or heated when its temperature exceeds an upper temperature limit or falls below a lower temperature limit, in which if the oxygen content of the Atmosphere volume ( 2 ) exceeds an upper oxygen limit value, a nitrogen stream is introduced into the atmosphere volume ( 2 ) until the oxygen content of the atmosphere volume ( 2 ) reaches a lower oxygen limit value, at which, when the oxygen content of the atmosphere volume ( 2 ) reaches the lower limit value, checked whether the relative humidity of the atmosphere volume ( 2 ) is above or below an upper humidity limit value, at which, if the relative humidity of the atmosphere volume ( 2 ) is above the upper humidity limit value, a dry, oxygen-containing gas stream is introduced into the atmosphere volume ( 2 ) until either the relative Humidity of the atmosphere volume ( 2 ) falls below the upper humidity limit value or the oxygen content of the atmosphere volume ( 2 ) reaches the upper oxygen limit value, whereby if the upper oxygen limit value is reached before the upper humidity limit value is undershot, a purer nitrogen stream is again introduced into the atmosphere volume ( 2 ) and this alternating introduction of a dry, oxygen-containing gas stream and a purer nitrogen stream is continued until both the relative humidity of the atmosphere volume ( 2 ) is below the upper humidity limit value and the oxygen content of the atmosphere volume ( 2 ) between the upper and the lower oxygen limit. 34. Method according to claim 33, in which the carbon dioxide content of the atmosphere volume ( 2 ) is kept between an upper and a lower carbon dioxide limit value, in which carbon dioxide is introduced into the atmosphere volume ( 2 ) when the lower carbon dioxide limit value is undershot and the carbon dioxide content is exceeded when the upper carbon dioxide limit value is exceeded Supply of an oxygen-containing gas stream or a nitrogen stream in the atmosphere volume ( 2 ) is reduced to the ambient carbon dioxide concentration. 35. The method of claim 33 or 34, wherein the ethylene content of the atmosphere volume (2) is maintained below an upper ethylene limit, in which on exceeding the upper ethylene limit an oxygen-containing gas stream or a nitrogen stream is introduced into the atmosphere volume (2) until the Ethylene content of the atmosphere volume is below the upper limit of ethylene. 36. The method according to any one of claims 33 to 35, in which the relative humidity of the atmosphere volume ( 2 ) is kept above a lower humidity limit value, in which water is atomized below the lower humidity limit value and introduced into the atmosphere volume until the relative humidity of the atmosphere volume ( 2 ) is above the lower moisture limit.