METHOD FOR THE MAINTENANCE OF AN AIRCRAFT AIR CONDITIONING SYSTEM AND AIRCRAFT AIR CONDITIONING SYSTEM

Description

[0001] The invention relates to a method for maintaining an aircraft air conditioning system and an aircraft air conditioning system.

[0002] On board an aircraft, especially a passenger aircraft, the occurrence of unpleasant odors should be avoided wherever possible. Reducing unpleasant odors is usually possible by reducing the water content in the aircraft's air distribution system, as dry air is typically perceived as "fresher" than humid air. Furthermore, it may be necessary to remove undesirable substances such as bacteria, viruses, or the like from the aircraft's air distribution system.

[0003] US Pat. No. 9,526,806 B2 discloses a method and system for decontaminating aircraft compartments. Depending on the detected contaminants, the disinfectant to be injected, the air flow, the air temperature, and the humidity are selected to decontaminate the aircraft compartments.

[0004] From the article entitled "A Novel Aircraft Air Conditioning System with a Sterilization Unit by Ultra-High-Temperature Air Stream" published in the journal "Transactions of Nanjing University of Aeronautics and Astronautics", Volume 37, Number 4, it is known to use a high-temperature air stream to decontaminate a volume of recirculated air in a bypass line of an aircraft air conditioning system before the recirculated air is cooled and then fed back into the aircraft cabin as part of the conditioned mixed air.

[0005] The invention is based on the object of providing a method for maintaining an aircraft air conditioning system and an aircraft air conditioning system which enable a controlled decontamination of an air distribution system of an aircraft to eliminate bad odors and / or undesirable substances.

[0006] This object is achieved by a method for maintaining an aircraft air conditioning system having the features of patent claim 1 and an aircraft air conditioning system having the features of patent claim 7.

[0007] In a method for servicing an aircraft air conditioning system, a maintenance control unit is connected to a control system of the aircraft air conditioning system. The maintenance control unit is preferably a control unit that is temporarily connected to the control system of the aircraft air conditioning system by a maintenance crew during ground operations of the aircraft. For example, the maintenance control unit can be designed in the form of a portable control unit that is brought on board the aircraft by the maintenance crew. Alternatively, however, it is also conceivable to use a control unit provided on board the aircraft as the maintenance control unit, which can be activated by the maintenance crew, for example, during ground operations of the aircraft.

[0008] In the next step, a decontamination activation signal issued by the maintenance control unit is transmitted to the aircraft air conditioning control system to activate a decontamination process. The aircraft air conditioning control system may comprise a plurality of control units for controlling the operation of the various sections of the aircraft air conditioning system. For example, the aircraft air conditioning control system may comprise a bleed air system control unit, a pack control unit, and a central zone control unit.

[0009] The bleed air system control unit can be provided to control the operation of a bleed air system of the aircraft air conditioning system, and in particular the supply of bleed air from an engine or an auxiliary power unit of the aircraft to the aircraft air conditioning system. The pack control unit is preferably configured to control the operation of a climate pack of the aircraft air conditioning system. The central zone control unit is preferably configured to control the supply of appropriately tempered air conditioning air to the individual climate zones of an aircraft cabin. For example, the central zone control unit can be configured to control the operation of air conditioning components, such as valves, fans, etc., that are assigned to an air conditioning supply system of the aircraft air conditioning system.All control units of the aircraft air conditioning control system are preferably connected to a Flight Warning System, which is configured to issue a corresponding warning signal in the event of a malfunction of the aircraft air conditioning system. Furthermore, a status indicator can be provided, which may indicate that decontamination of at least a portion of the aircraft's air distribution system is being performed.

[0010] The output of the decontamination activation signal by the maintenance control unit can be initiated manually, for example, if it is determined during a previous flight or by the maintenance crew during ground operations of the aircraft that decontamination of at least a portion of the aircraft's air distribution system is desired or necessary to eliminate unpleasant odors and / or undesirable substances. Alternatively or additionally, however, it is also conceivable for the maintenance control unit to output the decontamination activation signal automatically, for example, if the maintenance control unit receives a signal from a corresponding measuring device or a control unit of the aircraft indicating that decontamination of the aircraft's air distribution system is desired or necessary.The section of the air distribution system to be decontaminated can also be selected manually by the maintenance crew or automatically in response to the receipt of a corresponding signal issued by a measuring device or a control device to the maintenance control unit.

[0011] In response to receiving the decontamination activation signal, the control system of the aircraft air conditioning system controls the operation of the aircraft air conditioning system such that at least one sub-area of ​​the air distribution system of an aircraft equipped with the aircraft air conditioning system that is to be decontaminated is heated to a decontamination temperature that is higher than an operating temperature of the sub-area of ​​the air distribution system during normal operation of the aircraft air conditioning system. By heating to the decontamination temperature, the water vapor partial pressure in the area of ​​the air distribution system exposed to the decontamination temperature is increased and, consequently, the water content in this area of ​​the air distribution system is reduced. This can eliminate unpleasant odors. Furthermore, the elevated temperatures remove undesirable substances such as bacteria, viruses, or the like from the air distribution system.

[0012] The method according to the invention for servicing an aircraft air conditioning system enables automatic, controlled decontamination of the air distribution system of the aircraft air conditioning system, which is carried out efficiently even under difficult environmental conditions, e.g., cold ambient temperatures, under the control of the aircraft air conditioning system's control system. The time-consuming use of simulation tools, which allow a manual temperature increase in the air distribution system of the aircraft air conditioning system by bypassing the sensors and control units of the aircraft air conditioning system, can therefore be advantageously dispensed with. Furthermore, overheating of individual sub-areas and / or components of the air distribution system is reliably prevented.

[0013] Preferably, in response to receiving the decontamination activation signal, the control system of the aircraft air conditioning system controls the operation of the aircraft air conditioning system such that the decontamination temperature is maintained for a defined period of time in the sub-area of ​​the air distribution system to be decontaminated. The period of time is preferably predetermined by the decontamination activation signal output by the maintenance control unit and can be adapted to the respective decontamination task. For example, a longer period of time can be provided for maintaining the decontamination temperature if it is determined that the sub-area of ​​the air distribution system to be decontaminated contains a large amount of water or if specific bacteria and / or viruses are to be specifically removed from the sub-area of ​​the air distribution system to be decontaminated.

[0014] Additionally or alternatively, the control system of the aircraft air conditioning system can control the operation of the aircraft air conditioning system for decontaminating at least a portion of the air distribution system depending on at least one environmental parameter. An important environmental parameter that is preferably taken into account when controlling the operation of the aircraft air conditioning system for decontaminating at least a portion of the air distribution system is, for example, the ambient temperature.

[0015] For example, in cold ambient temperatures, it can be difficult to control an aircraft air conditioning compressor on its own to heat it to the desired decontamination temperature. However, in cold ambient temperatures, the aircraft air conditioning control system can respond to these challenging conditions by, for example, controlling the operation of components upstream of the compressor so that warmer air is supplied to the compressor, allowing the compressor to be heated to the desired decontamination temperature.

[0016] To activate decontamination of a bleed air system in the air distribution system, the maintenance control unit sends a bleed air system decontamination activation signal to the aircraft air conditioning control system. Upon receipt of the bleed air system decontamination activation signal, the aircraft air conditioning control system then controls the operation of a bleed air system in the aircraft air conditioning system such that the bleed air system in the air distribution system is heated to a decontamination temperature of approximately 220 to 240°C, which is higher than the operating temperature of the bleed air system during normal operation of the aircraft air conditioning system. This enables targeted, controlled decontamination of the bleed air system in the air distribution system.The bleed air system preferably comprises at least one bleed air line connecting an engine and / or an auxiliary power unit of the aircraft to a climate pack, in particular a primary heat exchanger of the climate pack, as well as components connected to this line, such as valves or the like. Furthermore, the bleed air system can comprise a bleed air temperature sensor for monitoring the temperature of the bleed air supplied to the climate pack.

[0017] The decontamination of the bleed air system is preferably controlled by the bleed air system control unit of the aircraft air conditioning control system, which, during normal operation of the aircraft air conditioning system, is designed to control the supply of bleed air from an engine or an auxiliary power unit of the aircraft to the aircraft air conditioning system. Accordingly, the bleed air system control unit has access to all essential components of the bleed air system that are to be controlled and can therefore perform all control interventions required to heat the bleed air system to the decontamination temperature.

[0018] Preferably, the bleed air system of the air distribution system is heated to a decontamination temperature of approximately 230 °C. This temperature ensures proper decontamination of the bleed air system. At the same time, overheating of components installed in the bleed air system of the air distribution system is reliably prevented.

[0019] A primary heat exchanger of the aircraft air conditioning system connected to a bleed air line can be optionally included in or excluded from a bleed air system decontamination process. For example, the primary heat exchanger can be included in the bleed air system decontamination process if the primary heat exchanger is also to be decontaminated and / or if air at an elevated temperature is to be supplied to a compressor located downstream of the primary heat exchanger. This may be desirable or necessary, for example, if the compressor is also to be decontaminated but cannot be heated to the desired decontamination temperature on its own in cold ambient temperatures.In order to include or exclude the primary heat exchanger from the process for decontamination of the bleed air system, a bleed air control valve arranged upstream of the heat exchanger in the bleed air line can be controlled accordingly, for example by the bleed air system control unit.

[0020] To activate decontamination of a compressor section of the air distribution system, the maintenance control unit outputs a compressor section decontamination activation signal to the aircraft air conditioning control system. In response to receiving the compressor section decontamination activation signal, the aircraft air conditioning control system then controls the operation of a compressor of the aircraft air conditioning system such that the compressor section of the air distribution system is heated to a decontamination temperature of approximately 210 to 230°C, which is higher than the operating temperature of the compressor section during normal operation of the aircraft air conditioning system. This enables targeted, controlled decontamination of the compressor section of the air distribution system. The compressor section preferably comprises a compressor that forms a component of an air conditioning pack of the aircraft air conditioning system.Furthermore, components of the aircraft air conditioning system arranged downstream of the compressor can be assigned to the compressor area.

[0021] The decontamination of the compressor area is preferably controlled by the pack control unit of the aircraft air conditioning control system, which, during normal operation of the aircraft air conditioning system, is designed to control the operation of the aircraft air conditioning components located in the compressor area, and in particular the components of the aircraft air conditioning pack. Accordingly, the pack control unit has access to all essential components to be controlled that are installed in the compressor area and can therefore perform all control interventions necessary to heat the compressor area to the decontamination temperature.

[0022] Preferably, the compressor section of the air distribution system is heated to a decontamination temperature of approximately 220 °C. This temperature ensures proper decontamination of the compressor section. At the same time, overheating of components installed in the compressor section of the air distribution system is reliably prevented.

[0023] Preferably, the compressor area comprises a main heat exchanger of the aircraft air conditioning system connected to an outlet of the compressor. Accordingly, the main heat exchanger can advantageously be included in a process for decontamination of the compressor area and can also be decontaminated.

[0024] Furthermore, other components of the aircraft air conditioning system arranged downstream of the compressor or the main heat exchanger, such as an afterheater, a condenser, a turbine and corresponding lines and valves, can also be assigned to the compressor area.

[0025] To activate decontamination of an air conditioning air supply system of the air distribution system, the maintenance control unit can output an air conditioning air supply system decontamination activation signal to the aircraft air conditioning control system.In response to receiving the air conditioning system decontamination activation signal, the control system of the aircraft air conditioning system can control the operation of an air conditioning pack of the aircraft air conditioning system connected to the air conditioning system of the air distribution system, the operation of at least one trim air valve arranged in the air conditioning system of the air distribution system, and / or the operation of at least one recirculation air blower provided in the air conditioning system of the air distribution system such that the air conditioning system of the air distribution system is heated to a decontamination temperature that is higher than the operating temperature of the air conditioning system during normal operation of the aircraft air conditioning system. This enables targeted, controlled decontamination of the air conditioning system of the air distribution system.

[0026] The air conditioning supply system preferably comprises at least one line connecting a climate pack of the aircraft air conditioning system to a region of the aircraft cabin to be air-conditioned. Furthermore, components of the aircraft air conditioning system that control the air conditioning flow from a climate pack into a region of the aircraft cabin to be air-conditioned, such as corresponding fans, valves, and the like, can be assigned to the air conditioning supply system. A mixing chamber in which the air conditioning air provided by the climate pack is mixed with recirculation air discharged from the aircraft cabin, at least one recirculation fan, at least one recirculation air line connecting a region of the aircraft cabin to be air-conditioned to the mixing chamber, a trim air valve, and a trim air line configured to direct trim air into the mixing chamber can also be assigned to the air conditioning supply system.

[0027] The decontamination of the air conditioning supply system is preferably controlled by the pack control unit and / or the central zone control unit of the aircraft air conditioning control system. By incorporating the pack control unit into a process for decontamination of the air conditioning supply system, the temperature of the air at the outlet of the air conditioning pack can be controlled as desired before entering the air conditioning supply system. In particular, the temperature of the air at the outlet of the air conditioning pack can be increased to heat the air conditioning supply system to the desired elevated decontamination temperature.During normal operation of the aircraft air conditioning system, the central zone control unit is designed to control the operation of the components of the aircraft air conditioning system, in particular the valves and fans that enable the supply of air conditioning and recirculation air into the mixing chamber of the aircraft air conditioning system and further into an area of ​​the aircraft cabin to be air-conditioned. By appropriately controlling the trim air valve, warm trim air can be supplied as needed to heat the air conditioning system to the desired elevated decontamination temperature.

[0028] Preferably, the air conditioning air supply system of the air distribution system is heated to a decontamination temperature of approximately 60 to 80 °C, in particular approximately 70 °C. This temperature ensures proper decontamination of the air conditioning air supply system. At the same time, overheating of components installed in the air conditioning air supply system of the air distribution system is prevented.

[0029] The decontamination temperature in the air conditioning supply system of the air distribution system is preferably determined based on a permissible maximum temperature of the air conditioning supplied to an avionics area of ​​the aircraft cabin. This prevents overheating of electronic components installed in the avionics area.

[0030] An aircraft air conditioning system comprises an aircraft air conditioning system with a control system. Furthermore, the aircraft air conditioning system comprises a maintenance control unit that is connectable to the control system of the aircraft air conditioning system and configured to output a decontamination activation signal for activating a decontamination process and to transmit it to the control system of the aircraft air conditioning system. The control system of the aircraft air conditioning system is configured, in response to receiving the decontamination activation signal, to control the operation of the aircraft air conditioning system such that at least one sub-region of an air distribution system of an aircraft equipped with the aircraft air conditioning system that is to be decontaminated is heated to a decontamination temperature that is higher than an operating temperature of the sub-region of the air distribution system during normal operation of the aircraft air conditioning system.

[0031] The control system of the aircraft air conditioning system is preferably configured to control the operation of the aircraft air conditioning system such that the decontamination temperature is maintained for a defined period of time in the partial area of ​​the air distribution system to be decontaminated. Furthermore, the control system of the aircraft air conditioning system can be configured to control the operation of the aircraft air conditioning system for decontaminating at least a partial area of ​​the air distribution system depending on at least one ambient parameter, in particular depending on an ambient temperature.Furthermore, the control system of the aircraft air conditioning system can be configured to control the operation of the aircraft air conditioning system for decontaminating at least a portion of the air distribution system depending on the operating state of at least one recirculation air blower and / or depending on the operating state of a trim air system, in particular at least one trim air valve. The goal is to generate the highest possible temperature for heating the cabin and cockpit, in particular to eliminate viruses and / or bacteria, without exceeding the permitted temperatures in an avionics air supply line.

[0032] The maintenance control unit is preferably configured to output a bleed air system decontamination activation signal to the control system of the aircraft air conditioning system to activate decontamination of a bleed air system of the air distribution system. The control system of the aircraft air conditioning system can be configured, in response to receiving the bleed air system decontamination activation signal, to control the operation of a bleed air system of the aircraft air conditioning system such that the bleed air system of the air distribution system is heated to a decontamination temperature that is higher than the operating temperature of the bleed air system during normal operation of the aircraft air conditioning system.

[0033] The control system of the aircraft air conditioning system can comprise a bleed air system control unit configured to control the decontamination of the bleed air system. Furthermore, the control system of the aircraft air conditioning system can comprise a central zone control unit. The central zone control unit can be configured to forward the bleed air system decontamination activation signal output by the maintenance control unit to the bleed air system control unit. The decontamination temperature in the bleed air system of the air distribution system is preferably approximately 220 to 240°C, in particular approximately 230°C. The bleed air system control unit can be configured to selectively include a primary heat exchanger of the aircraft air conditioning system connected to a bleed air line in a process for decontamination of the bleed air system or to exclude it from this process.To achieve this, the bleed air system control unit can be configured to control a bleed air control valve arranged upstream of the primary heat exchanger in the bleed air line accordingly.

[0034] The maintenance control unit is preferably further configured to output a compressor section decontamination activation signal to the control system of the aircraft air conditioning system to activate decontamination of a compressor section of the air distribution system. The control system of the aircraft air conditioning system can be configured, in response to receiving the compressor section decontamination activation signal, to control the operation of a compressor of the aircraft air conditioning system such that the compressor section of the air distribution system is heated to a decontamination temperature that is higher than the operating temperature of the compressor section during normal operation of the aircraft air conditioning system.

[0035] The control system of the aircraft air conditioning system may include a pack control unit configured to control the decontamination of the compressor section. The central zone control unit may be configured to forward the compressor section decontamination activation signal output by the maintenance control unit to the pack control unit. The decontamination temperature in the compressor section of the air distribution system is preferably approximately 210 to 230°C, in particular approximately 220°C. The compressor section preferably includes a main heat exchanger of the aircraft air conditioning system connected to an outlet of the compressor.

[0036] The maintenance control device can further be configured to output an air conditioning air supply system decontamination activation signal to the control system of the aircraft air conditioning system in order to activate decontamination of an air conditioning air supply system of the air distribution system.The control system of the aircraft air conditioning system can be configured, in response to the receipt of the air conditioning air supply system decontamination activation signal, to control the operation of an air conditioning pack of the aircraft air conditioning system connected to the air conditioning air supply system of the air distribution system, the operation of at least one trim air valve arranged in the air conditioning air supply system of the air distribution system and / or the operation of at least one recirculation air blower arranged in the air conditioning air supply system of the air distribution system such that the air conditioning air supply system of the air distribution system is heated to a decontamination temperature that is higher than the operating temperature of the air conditioning air supply system during normal operation of the aircraft air conditioning system.

[0037] The central zone control unit and / or the pack control unit of the aircraft air conditioning system control system can be configured to control the decontamination of the air conditioning air supply system. The central zone control unit can be configured to forward the air conditioning air supply system decontamination activation signal output by the maintenance control unit to the pack control unit. The decontamination temperature in the compressor area of ​​the air distribution system is preferably approximately 60 to 80°C, in particular approximately 70°C. The central zone control unit and / or the pack control unit is / are preferably configured to determine the decontamination temperature in the air conditioning air supply system of the air distribution system as a function of a permissible maximum temperature of air conditioning air directed into an avionics area.

[0038] A preferred embodiment of the invention will now be explained in more detail with reference to the accompanying schematic drawings, of which Figure 1 shows an aircraft air conditioning system with a schematically indicated aircraft air conditioning system and a maintenance control unit, wherein the maintenance control unit is connected to a control system of the aircraft air conditioning system; Figure 2 shows a bleed air system of an air distribution system of the aircraft air conditioning system; Figure 3 shows a compressor area of ​​an air distribution system of the aircraft air conditioning system; and Figure 4 shows an air conditioning supply system of the aircraft air conditioning system.

[0039] Figure 1 shows an aircraft air conditioning system 1000 which is one of the Figure 1The diagrammatic representation comprises an aircraft air conditioning system 10, which is only schematically indicated, and a maintenance control unit 100. In the embodiment shown here, the maintenance control unit 100 is designed as a portable control unit that is brought aboard an aircraft equipped with the aircraft air conditioning system 10 by a maintenance crew during ground operation and is temporarily connected to a control system 12 of the aircraft air conditioning system 10. Alternatively, an internal maintenance interface can also be used.

[0040] The control system 12 of the aircraft air conditioning system 10 comprises two bleed air system control units 14, two pack control units 16 and a central zone control unit 18. All control units 14, 16, 18 of the control system 12 of the aircraft air conditioning system 10 are connected to a flight warning system 19, which is configured to issue a corresponding warning signal in the event of a malfunction of the aircraft air conditioning system 10.

[0041] During normal operation of the aircraft air conditioning system 10, the bleed air system control units 14 control the operation of a Figure 2 schematically illustrated bleed air system 20 of the aircraft air conditioning system 10 and in particular the supply of bleed air from an engine 22 or an auxiliary power unit of the aircraft to the aircraft air conditioning system 10. The bleed air system 20 comprises two bleed air lines 24, each connecting an engine 22 to a climate pack 26. Furthermore, in the bleed air system 20 in Figure 3 Components not shown, such as bleed air branch lines for tapping bleed air at different points of the engine 22 as well as valves and the like for controlling the bleed air flow through the bleed air lines 24, are provided.

[0042] Each of the bleed air lines 24 is assigned a bleed air temperature sensor 28 for monitoring the temperature of the bleed air supplied to the corresponding climate pack 26. Signals output by the bleed air temperature sensors 28, which indicate the temperature of the bleed air flowing through the corresponding bleed air line 24, are transmitted to the corresponding bleed air system control unit 14. Furthermore, each of the bleed air lines 24 includes a bleed air control valve 30, which is operated under the control of the corresponding pack control unit 16 to control the supply of bleed air to a climate pack 26.

[0043] During normal operation of the aircraft air conditioning system 10, each pack control unit 16 controls the operation of a Figure 3more detailed illustrated climate packs 26 of the aircraft air conditioning system 10. Each climate pack 26 comprises a primary heat exchanger 32 connected to a bleed air line 24 and a compressor area 34 arranged downstream of the primary heat exchanger 32. The compressor area 34 is assigned a compressor 36, a main heat exchanger 38 connected to an outlet of the compressor 36 and further components arranged downstream of the compressor 36 or the main heat exchanger 38, in particular a reheater 40, a condenser 42, a turbine 44 and corresponding lines and valves. A pack valve 46 is designed in the form of a check valve and prevents the backflow of air conditioning air from a pressurized area 47b of the aircraft into an unpressurized area 47a of the aircraft. In the printed area 47b of the aircraft, a Figure 4 shown air conditioning air supply system 48 installed.

[0044] The air conditioning supply system 48 comprises a plurality of lines that connect the air conditioning packs 26 to corresponding climate zones 50a, 50b, 50c, 50d, 50e of an aircraft cabin 52. Furthermore, components of the aircraft air conditioning system 10 are assigned to the air conditioning supply system 48, which control the air conditioning flow from a air conditioning pack 26 into a climate zone 50a, 50b, 50c, 50d, 50e of the aircraft cabin 52, in particular corresponding fans, valves, and the like. A mixing chamber 54, in which the air conditioning air provided by the climate packs 26 is mixed with recirculation air discharged from the aircraft cabin 52, recirculation fans 56, recirculation air lines, trim air valves 58 and a trim air line which serves to direct hot trim air into the mixing chamber 54, can also be assigned to the air conditioning air supply system 48.

[0045] During normal operation of the aircraft air conditioning system 10, the central zone control unit 18 controls the supply of appropriately tempered air conditioning to the individual climate zones 50a, 50b, 50c, 50d, 50e. In particular, the central zone control unit 18 controls the operation of the valves, fans, etc. provided in the air conditioning supply system 48.

[0046] In a method for servicing the aircraft air conditioning system 10, the maintenance control unit 100 is connected to the control system 12 of the aircraft air conditioning system 10. If the maintenance crew determines that decontamination of at least a portion of an aircraft air distribution system formed by the bleed air system 20, the compressor section 34, and the air conditioning supply system 48 is desired or necessary to eliminate unpleasant odors and / or undesirable substances, the maintenance crew initiates the output of a decontamination activation signal to activate a decontamination process. The maintenance crew can select which portion of the air distribution system is to be decontaminated from a selection menu provided by the maintenance control unit 100. The decontamination activation signal output by the maintenance control unit 100 is transmitted to the control system 12 of the aircraft air conditioning system 10.

[0047] In response to receiving the decontamination activation signal, the control system 12 of the aircraft air conditioning system 10 controls the operation of the aircraft air conditioning system 10 such that at least one sub-area of ​​the air distribution system to be decontaminated is heated to a decontamination temperature that is higher than an operating temperature of the sub-area of ​​the air distribution system during normal operation of the aircraft air conditioning system 10. This reduces the water content in this area of ​​the air distribution system, thereby eliminating unpleasant odors. In addition, the increased temperatures remove unwanted substances such as bacteria, viruses, or the like from the air distribution system. Furthermore, the Flight Warning System displays a status message on a system display indicating that decontamination of at least one sub-area of ​​the aircraft's air distribution system is in progress.

[0048] In response to receiving the decontamination activation signal, the control system 12 of the aircraft air conditioning system 10 controls the operation of the aircraft air conditioning system 10, in particular such that the decontamination temperature is maintained for a defined period of time in the sub-area of ​​the air distribution system to be decontaminated. This period of time is predetermined by the decontamination activation signal output by the maintenance control unit 100 and is adapted to the respective decontamination task. In particular, a longer period of time will be provided for maintaining the decontamination temperature if the sub-area of ​​the air distribution system to be decontaminated contains a large amount of water or if specific bacteria and / or viruses are to be specifically removed from the sub-area of ​​the air distribution system to be decontaminated.

[0049] In addition, the control system 12 of the aircraft air conditioning system 10 controls the operation of the aircraft air conditioning system 10 for decontaminating at least a portion of the air distribution system as a function of at least one ambient parameter, in particular as a function of the ambient temperature. Furthermore, the control system 12 of the aircraft air conditioning system 10 controls the operation of the aircraft air conditioning system 10 for decontaminating at least a portion of the air distribution system as a function of the operating state of at least one recirculation air blower 56 and / or as a function of the operating state of the trim air system, in particular at least one trim air valve 58, in order to generate the highest possible temperature for heating the cabin 52 and the cockpit without exceeding the permitted temperatures in an avionics air supply line.

[0050] If decontamination of the bleed air system 20 of the air distribution system is to be performed, the maintenance crew selects the corresponding menu item "Bleed Air System Decontamination" in the selection menu of the maintenance control unit 100. The maintenance control unit 100 then outputs a bleed air system decontamination activation signal to the control system 12 of the aircraft air conditioning system 10. The bleed air system decontamination activation signal is output to the central zone control unit 18, which in turn forwards the signal to one or both of the bleed air system control units 14.

[0051] In response to receiving the bleed air system decontamination activation signal, the control system 12 of the aircraft air conditioning system 10, i.e. one of the bleed air system control units 14 or both bleed air system control units 14, then controls the operation of the bleed air system 20 such that the bleed air system 20 is heated to a decontamination temperature which is higher than the operating temperature of the bleed air system 20 during normal operation of the aircraft air conditioning system 10. This is achieved, for example, by supplying bleed air to the bleed air system 20 which has a higher temperature than during normal operation of the bleed air system 20. In particular, the bleed air region 20 is heated to a decontamination temperature of approximately 220 to 240 °C, preferably approximately 230 °C. During normal operation, however, the bleed air system 20 is generally operated at a temperature of approximately 200 °C. The temperature in the bleed air system 20 is monitored using the bleed air temperature sensors 28.

[0052] A primary heat exchanger 32 of a climate pack 26 connected to the bleed air line 24 can be optionally included in a process for decontamination of the bleed air system 20 or excluded from this process. For example, the primary heat exchanger 32 can be included in the process for decontamination of the bleed air system 20 if the primary heat exchanger 32 is also to be decontaminated and / or if air at an elevated temperature is to be supplied to the compressor 36 arranged downstream of the primary heat exchanger 32. To include the primary heat exchanger 32 in the process for decontamination of the bleed air system 20, the bleed air control valve 30 arranged upstream of the primary heat exchanger 32 in the bleed air line 24 is opened under the control of the pack control unit 16.If, however, the primary heat exchanger 32 is to be excluded from the process for decontamination of the bleed air system 20, the bleed air control valve 30 remains closed under the control of the pack control unit 16.

[0053] If decontamination of the compressor area 34 of the air distribution system is to be performed, the maintenance crew selects the corresponding menu item "Compressor Area Decontamination" in the selection menu of the maintenance control unit 100. The maintenance control unit 100 then outputs a compressor area decontamination activation signal to the control system 12 of the aircraft air conditioning system 10. The compressor area decontamination activation signal is output to the central zone control unit 18, which in turn forwards the signal to one or both of the pack control units 16.

[0054] In response to receiving the compressor section decontamination activation signal, the control system 12 of the aircraft air conditioning system 10, i.e., one of the pack control units 16 or both pack control units 16, then controls the operation of the compressor 36 such that the compressor section 34 is heated to a decontamination temperature that is higher than the operating temperature of the compressor section 34 during normal operation of the aircraft air conditioning system 10. In particular, the compressor section 34 is heated to a decontamination temperature of approximately 210 to 230 °C, preferably approximately 220 °C. During normal operation of the aircraft air conditioning system 10, however, the compressor section 34 is typically operated at a temperature of approximately 185 °C.The heating of the compressor area 34 to the decontamination temperature is achieved by increasing the operating temperature of the compressor 36, which in turn is achieved by a corresponding control of a ram air inlet flap to a more closed position than in normal operation of the aircraft air conditioning system 10.

[0055] In the event that, under certain ambient conditions, for example, cold ambient temperatures, it is not possible to heat the compressor 36 to the desired elevated temperature required for decontamination of the compressor area 84, the maintenance crew selects a corresponding menu item "Decontamination of the bleed air system + compressor area" in the selection menu of the maintenance control unit 100. The maintenance control unit 100 then outputs a bleed air system decontamination activation signal and a compressor area decontamination activation signal to the control system 12 of the aircraft air conditioning system 10. Furthermore, under the control of the pack control unit 16, the bleed air control valve 30 located upstream of the primary heat exchanger 32 in the bleed air line 24 is opened.

[0056] As a result, air at an elevated temperature is supplied to the compressor 36, making it easier to heat the compressor 36 to the desired elevated decontamination temperature. Furthermore, with such control of the aircraft air conditioning system 10, the primary heat exchanger 32 arranged upstream of the compressor 36 is also included in the decontamination process.

[0057] If decontamination of the air conditioning air supply system 48 of the air distribution system is to be performed, the maintenance crew selects the corresponding menu item "Decontamination of the Air Conditioning Air Supply System" in the selection menu of the maintenance control unit 100. The maintenance control unit 100 then outputs an air conditioning air supply system decontamination activation signal to the control system 12 of the aircraft air conditioning system 10. The air conditioning air supply system decontamination activation signal is output to the central zone control unit 18.

[0058] In response to receiving the air conditioning supply system decontamination activation signal, the control system 12 of the aircraft air conditioning system 10, i.e. the central zone control unit 18 and / or at least one of the pack control units 16, controls the operation of at least one air conditioning pack 26 connected to the air conditioning supply system 48, the operation of the trim air valves 58 and / or the operation of at least one recirculation air blower 56 such that the air conditioning supply system 48 is heated to a decontamination temperature that is higher than the operating temperature of the air conditioning supply system 48 during normal operation of the aircraft air conditioning system 10. The decontamination temperature in the air conditioning supply system 48 is determined as a function of a permissible maximum temperature of air conditioning air directed into an avionics area 50a of the aircraft cabin 52. In particular, the air conditioning air supply system 48 is heated to a decontamination temperature of approximatelyHeated to 60 to 80 °C, preferably from approx. 70 °C.

[0059] The heating of the air conditioning supply system 48 to the decontamination temperature is achieved by increasing the temperature of the air at the outlet of one or both climate packs 26 before entering the air conditioning supply system 48 under the control of one pack control unit 16 or both pack control units 16, the supply of warm trim air by opening the trim air valves 58 under the control of the central zone control unit 18 and / or a corresponding operation of the recirculation fans 56 under the control of the central zone control unit 18.

Claims

1. Method for maintaining an aircraft air-conditioning system (10), comprising the steps of: - connecting a maintenance control device (100) to a control system (12) of the aircraft air-conditioning system (10); and - transmitting a decontamination activation signal, output by the maintenance control device (100), for the activation of a decontamination process to the control system (12) of the aircraft air-conditioning system (10), wherein, in response to receiving the decontamination activation signal, the control system (12) of the aircraft air-conditioning system (10) controls the operation of the aircraft air-conditioning system (10) such that at least a partial region to be decontaminated of an air distribution system (20, 34, 48) of an aircraft equipped with the aircraft air-conditioning system (10) is heated to a decontamination temperature that is higher than an operating temperature of the partial region of the air distribution system (20, 34, 48) during normal operation of the aircraft air-conditioning system (10), characterized in that the maintenance control device (100): - for activating a decontamination of a bleed air system (20) of the air distribution system (20, 34, 48), outputs a bleed-air-system decontamination activation signal to the control system (12) of the aircraft air-conditioning system (10) and, in response to receiving the bleed-air-system decontamination activation signal, the control system (12) of the aircraft air-conditioning system (10) controls the operation of the bleed air system (20) of the aircraft air-conditioning system (10) such that the bleed air system (20) of the air distribution system (20, 34, 48) is heated to a decontamination temperature of 220 to 240°C, which is higher than the operating temperature of the bleed air system (20) during normal operation of the aircraft air-conditioning system (10); and / or - for activating a decontamination of a compressor region (34) of the air distribution system (20, 34, 48), outputs a compressor-region decontamination activation signal to the control system (12) of the aircraft air-conditioning system (10) and, in response to receiving the compressor-region decontamination activation signal, the control system (12) of the aircraft air-conditioning system (10) controls the operation of a compressor (36) of the aircraft air-conditioning system (10) such that the compressor region (34) of the air distribution system (20, 34, 48) is heated to a decontamination temperature of 210 to 230°C, which is higher than the operating temperature of the compressor region (34) during normal operation of the aircraft air-conditioning system (10).

2. Method according to Claim 1, wherein - the control system (12) of the aircraft air-conditioning system (10) controls the operation of the aircraft air-conditioning system (10) such that the decontamination temperature is maintained for a defined period of time in the partial region to be decontaminated of the air distribution system (20, 34, 48), and / or - the control system (12) of the aircraft air-conditioning system (10) controls the operation of the aircraft air-conditioning system (10) for the decontamination of at least a partial region of the air distribution system (20, 34, 48) in dependence on at least one environmental parameter, in particular in dependence on an ambient temperature.

3. Method according to Claim 1 or 2, wherein - the decontamination of the bleed air system (20) is controlled by a bleed-air-system control device (14) of the control system (12) of the aircraft air-conditioning system (10), and / or - the bleed-air-system decontamination activation signal output by the maintenance control device (100) is passed on by a central zone control device (18) of the control system (12) of the aircraft air-conditioning system (10) to the bleed-air-system control device (14) of the control system (12) of the aircraft air-conditioning system (10), and / or - the bleed air system (20) of the air distribution system (20, 34, 48) is heated to a decontamination temperature of 230°C, and / or - a primary heat exchanger (32), connected to a bleed air line (24), of the aircraft air-conditioning system (10) is selectively included in a process for decontaminating the bleed air system (24) or excluded from this process, in particular by corresponding controlling of a bleed air control valve (30) situated upstream of the primary heat exchanger (32) in the bleed air line (24).

4. Method according to one of Claims 1 to 3, wherein - the decontamination of the compressor region (34) is controlled by a pack control device (16) of the control system (12) of the aircraft air-conditioning system (10), and / or - the compressor-region decontamination activation signal output by the maintenance control device (100) is passed on by the central zone control device (18) of the control system (12) of the aircraft air-conditioning system (10) to the pack control device (16) of the control system (12) of the aircraft air-conditioning system (10), and / or - the compressor region (34) of the air distribution system (20, 34, 48) is heated to a decontamination temperature of 220°C, and / or - the compressor region (34) includes a main heat exchanger (38) of the aircraft air-conditioning system (10), connected to an outlet of the compressor (36).

5. Method according to one of Claims 1 to 4, wherein the maintenance control device (100), for activating a decontamination of an air-conditioning air supply system (48) of the air distribution system (20, 34, 48), outputs an air-conditioning air-supply-system decontamination activation signal to the control system (12) of the aircraft air-conditioning system (10) and, in response to receiving the air-conditioning air-supply-system decontamination activation signal, the control system (12) of the aircraft air-conditioning system (10) controls the operation of an air-conditioning pack (26) of the aircraft air-conditioning system (10) connected to the air-conditioning air supply system (48) of the air distribution system (20, 34, 48), the operation of at least one trim air valve (58) situated in the air-conditioning air supply system (48) of the air distribution system (20, 34, 48) and / or the operation of at least one recirculation air blower (56) situated in the air-conditioning air supply system (48) of the air distribution system (20, 34, 48) such that the air-conditioning air supply system (48) of the air distribution system (20, 34, 48) is heated to a decontamination temperature that is higher than the operating temperature of the air-conditioning air supply system (48) during normal operation of the aircraft air-conditioning system (10).

6. Method according to Claim 5, wherein - the decontamination of the air-conditioning air supply system (48) is controlled by the pack control device (16) and / or the central zone control device (18) of the control system (12) of the aircraft air-conditioning system (10), and / or - the air-conditioning air-supply-system decontamination activation signal output by the maintenance control device (100) is passed on by the central zone control device (18) of the control system (12) of the aircraft air-conditioning system (10) to the pack control device (16) of the control system (12) of the aircraft air-conditioning system (10), and / or - the air-conditioning air supply system (48) of the air distribution system (20, 34, 48) is heated to a decontamination temperature of 60 to 80°C, in particular of 70°C, and / or - the decontamination temperature in the air-conditioning air supply system (48) of the air distribution system (20, 34, 48) is determined in dependence on an allowable maximum temperature of air-conditioning air conducted into an avionics region (50a).

7. Aircraft air-conditioning system setup (1000) comprising: - an aircraft air-conditioning system (10) having a control system (12) and - a maintenance control device (100), which can be connected to the control system (12) of the aircraft air-conditioning system (10) and is set up to output a decontamination activation signal for the activation of a decontamination process and to transmit it to the control system (12) of the aircraft air-conditioning system (10), wherein the control system (12) of the aircraft air-conditioning system (10) is set up so as to control the operation of the aircraft air-conditioning system (10) in response to receiving the decontamination activation signal such that at least a partial region to be decontaminated of an air distribution system (20, 34, 48) of an aircraft equipped with the aircraft air-conditioning system (10) is heated to a decontamination temperature that is higher than an operating temperature of the partial region of the air distribution system (20, 34, 48) during normal operation of the aircraft air-conditioning system (10), characterized in that the maintenance control device (100) is set up: - for activating a decontamination of a bleed air system (20) of the air distribution system (20, 34, 48), to output a bleed-air-system decontamination activation signal to the control system (12) of the aircraft air-conditioning system (10) and the control system (12) of the aircraft air-conditioning system (10) is set up so as to control the operation of the bleed air system (20) of the aircraft air-conditioning system (10) in response to receiving the bleed-air-system decontamination activation signal such that the bleed air system (20) of the air distribution system (20, 34, 48) is heated to a decontamination temperature of 220 to 240°C, which is higher than the operating temperature of the bleed air system (20) during normal operation of the aircraft air-conditioning system (10), and / or - for activating a decontamination of a compressor region (34) of the air distribution system (20, 34, 48), to output a compressor-region decontamination activation signal to the control system (12) of the aircraft air-conditioning system (10) and the control system (12) of the aircraft air-conditioning system (10) is set up so as to control the operation of a compressor (36) of the aircraft air-conditioning system (10) in response to receiving the compressor-region decontamination activation signal such that the compressor region (34) of the air distribution system (20, 34, 48) is heated to a decontamination temperature of 210 to 230°C, which is higher than the operating temperature of the compressor region (34) during normal operation of the aircraft air-conditioning system (10).

8. Aircraft air-conditioning system setup according to Claim 7, wherein - the control system (12) of the aircraft air-conditioning system (10) is set up so as to control the operation of the aircraft air-conditioning system (10) such that the decontamination temperature is maintained for a defined period of time in the partial region to be decontaminated of the air distribution system (20, 34, 48), and / or - the control system (12) of the aircraft air-conditioning system (10) is set up so as to control the operation of the aircraft air-conditioning system (10) for the decontamination of at least a partial region of the air distribution system (20, 34, 48) in dependence on at least one environmental parameter, in particular in dependence on an ambient temperature.

9. Aircraft air-conditioning system setup according to Claim 7 or 8, wherein the maintenance control device (100) is set up so as, for activating a decontamination of an air-conditioning air supply system (48) of the air distribution system (20, 34, 48), to output an air-conditioning air-supply-system decontamination activation signal to the control system (12) of the aircraft air-conditioning system (10) and the control system (12) of the aircraft air-conditioning system (10) is set up so as to control the operation of an air-conditioning pack (26) of the aircraft air-conditioning system (10) to the air-conditioning air supply system (48) of the air distribution system (20, 34, 48), the operation of at least one trim air valve (58) situated in the air-conditioning air supply system (48) of the air distribution system (20, 34, 48) and / or the operation of at least one recirculation air blower (56) situated in the air-conditioning air supply system (48) of the air distribution system (20, 34, 48) in response to receiving the air-conditioning air-supply-system decontamination activation signal such that the air-conditioning air supply system (48) of the air distribution system (20, 34, 48) is heated to a decontamination temperature that is higher than the operating temperature of the air-conditioning air supply system (48) during normal operation of the aircraft air-conditioning system (10).