FR3126694A1 - Removable heating system for aircraft - Google Patents

Abstract

A removable method of heating for an aircraft, comprising: -one or more radiant heaters (2) each comprising: a heating layer (3); an electrode layer (4) having one or more anodes and one or more cathodes; two front and rear protective layers (5, 6) arranged on either side of the assembly formed by the heating layer (3) and the electrode layer (4); - a plastic shell (7) attached to the front protective layer (5) of the radiant heater (2); And -removable fixing means (11) of the removable heating system (1; 14) on a support (12; 15a, 15b) Figure for abstract: Fig 1

Description

Removable heating system for aircraft

The present invention relates, in general, to a heating system for the thermal comfort of a passenger in an aircraft cabin.

In particular, the invention relates to a removable heating system for an aircraft comprising a radiant heating device, as well as a legrest unit of an aircraft seat assembly comprising such a heating system.

State of the art

Radiant electric heating, otherwise known as radiant heating, radiates heat.

This results in a sensation of intense and immediate heat.

In the field of transport, there are many radiant heating systems for motor vehicles.

Conventionally, the motor vehicle is equipped with a heating panel comprising a heating layer and a layer of anode and cathode electrodes interposed between two insulating layers. The heating panel is integrated into the dashboard of the motor vehicle and allows the heating of the upper parts of the passenger.

However, automotive radiant heating systems are not suitable for use in an aircraft.

Certification specific to the aeronautical sector is required and requires each device integrated into the aircraft to meet certain airworthiness constraints, in order to guarantee passenger safety.

The airworthiness constraints relate to the mechanical resistance of the device, in particular the fire resistance, the robustness to temperature stress and to mechanical stress. They also relate to safety, by guaranteeing that a fire does not start at a limited temperature and by guaranteeing a temperature limit which cannot injure the passenger. Finally, the airworthiness constraints impose the removable nature of the device, making it independent and thus certifiable independently of its support.

In order to facilitate obtaining airworthiness certification, the heating system requires a secure structure that can be dismantled from its support.

The object of the invention is therefore to remedy these drawbacks and to propose a radiant heating system making it possible to improve the thermal comfort of a passenger in an aircraft cabin, and adapted to meet aeronautical requirements for airworthiness certification, to be safe and easy to assemble and disassemble.

A removable heating system for an aircraft is therefore proposed, comprising:

- one or more radiant heating devices each comprising:

a heating layer;

a layer of electrodes comprising one or more anodes and one or more cathodes;

two front and rear protective layers arranged on either side of the assembly formed by the heating layer and the layer of electrodes;

- a plastic shell attached to the front protective layer of the radiant heater; And

- Removable fixing means of the removable heating system on a support.

Advantageously, the material of the front and rear protective layers can be chosen from: polyimide, epoxy resin composite reinforced with FR-4 glass fibers, polyethylene terephthalate, or a polyurethane thermoplastic.

Preferably, the material of the heating layer is able to limit the temperature below a threshold value.

Preferably, the radiant heating device comprises a radiant heat insulation layer disposed between the heating layer and the rear protective layer.

According to one feature, the radiant heater may include a conductive heat insulation layer disposed behind the rear protective layer.

According to one embodiment, the removable fixing means of the removable heating system can be configured to form a ventilation gap between the radiant heating device and the support.

The invention also relates to a legrest unit for an aircraft seat assembly, comprising a legrest panel and at least one removable heating system as previously described.

According to an exemplary embodiment, the legrest unit may comprise a recess for the legs of a passenger delimited by the legrest panel and an upper panel, at least one removable heating system as previously described being placed on the panel higher next to the recess.

Advantageously, the legrest unit can comprise a housing for the feet of a passenger delimited by the legrest panel and the floor, and at least one removable heating system as previously described on an underside of the legrest panel disposed facing said housing and/or on the ground facing said housing.

Even more advantageously, the legrest unit can comprise a front panel intended to be oriented towards a passenger and tilted downwards, the front panel comprising at least one removable heating system as previously described.

The invention also relates to an aircraft seat assembly comprising at least one heating system as previously described.

Additionally, the seat assembly may include a legrest unit as previously described.

The invention also relates to an aircraft comprising at least one seat assembly as previously described.

Other aims, advantages and characteristics will emerge from the description which follows, given for purely illustrative purposes and made with reference to the appended drawings in which:

is a sectional view of a removable heating system incorporating a radiant heating device according to one embodiment of the invention;

is a sectional view of the radiant heater of the ;

is a sectional view of a removable heating system incorporating a radiant heating device according to another embodiment of the invention;

is a sectional view of the radiant heater of the ;

illustrates a legrest unit of an aircraft seat assembly according to an exemplary embodiment of the invention;

illustrates a legrest unit of an aircraft seat assembly according to another exemplary embodiment of the invention.

In what follows, and unless otherwise indicated, the limits of a domain of values are included in this domain, in particular in the expression “included between”.

Furthermore, the expression “at least one” used in the present description is equivalent to the expression “one or more”.

Detailed description of an embodiment

There illustrates a removable heating system 1 for an aircraft according to a first embodiment.

The removable heating system 1 comprises at least one radiant heating device 2 comprising a plurality of stacked layers forming a multilayer structure.

As can be seen on the , the radiant heating device 2 comprises a heating or thermo-active layer 3.

The radiant heating device 2 also comprises a layer of electrodes 4 comprising at least one anode and one cathode.

According to an exemplary embodiment, the layer of electrodes 4, placed in direct contact with the heating layer 3, can comprise several anodes and several cathodes.

The layer of electrodes 4 forms a conductive zone providing the interface between electrical connections connected to the radiant heating device 2, which are for example flexible PCB cables, and the heating layer 3.

The heating layer 3, traversed by an electric current conveyed by the electrode layer 4, then emits radiant heat.

Preferably, the material of the heating layer 3 is capable of limiting the temperature below a threshold value. In other words, the material of the heating layer 3 is a conductive material having the properties of a thermistor.

According to one example, the material of the heating layer 3 has a high PTC, acronym for the term “Positive Temperature Coefficient” or a TCR, acronym for the term “Coefficient of Thermal Resistance”.

Such a material is capable of limiting the temperature of the removable heating system 1 in the event of a fault by increasing the electrical resistance, and makes it possible to avoid the risk of burning passengers.

For example, the material of the heating layer 3 is a carbon ink or a mixture of metals including copper.

In addition, the radiant heating device 2 comprises at least two protective layers, including a front protective layer 5 and a rear protective layer 6, arranged on either side of the assembly formed by the heating layer 3 and the layer of electrodes 4.

By front is meant the face of the removable heating system 1 intended to be oriented facing the passenger.

Conversely, rear means the face of the removable heating system 1 opposite the front face, intended to be oriented towards the support on which it is mounted.

The two front and rear protective layers 5, 6 ensure the resistance of the radiant heating device 2.

In order to meet aeronautical constraints, the material of the front and rear protective layers 5, 6 is, for example, chosen from one of the following materials: polyimide, an epoxy resin composite reinforced with glass fibers known as the abbreviation FR-4 for "Flame Retardant 4", polyethylene terephthalate known by the abbreviation PET, or a thermoplastic polyurethane known by the abbreviation TPU. These materials provide mechanical strength of the radiant heating device 2 meeting aeronautical requirements. In particular, these materials are fire resistant and have high mechanical strength.

In addition to the radiant heating device 2, the removable heating system 1 comprises a plastic shell 7. The plastic shell 7 includes an outer surface 7a directed towards the passenger and an inner surface 7b opposite the outer surface 7a. The radiant heating device 2 is fixed to the inner surface 7b of the plastic shell 7 by fixing means 8.

In the example illustrated, the front protective layer 5 of the radiant heating device 2 is directly attached to the inner surface 7b of the plastic shell 7.

The plastic shell 7 has a sufficiently high thermal conductivity for efficient heat transfer from the removable heating system 2 to a passenger and a mechanical strength meeting aeronautical requirements including fire resistance.

Preferably, the thermal conductivity λ of the plastic shell 7 is between 0.1 and 0.3 W/mK.

Furthermore, the thermal inertia of the plastic shell 7, defined by the product of the thermal conductivity, the density and the specific heat capacity, allows the plastic shell 7 to reach a temperature high enough to provide thermal comfort to the passenger and low enough for the latter to touch it without injury.

The material of the plastic shell 7 can be a thermoplastic, for example, chosen from: polyvinyl chloride (PVC), acrylic PVC or polycarbonate (PC).

In addition, the thermal conductivity of the fastening means 8 is advantageously high enough to allow conductive heat and radiant heat to pass to the passenger.

The thickness of the fixing means 8 is smaller than the thickness of the plastic shell 7 and the thickness of the radiant heating device 2.

For example, the fixing means 8 can comprise adhesive tape or glue.

According to a variant, the fixing means 8 can be configured so as to mount the radiant heating device 2 on the plastic shell 7 by assembly by simple pressure.

According to one embodiment, the heating layer 3 can be arranged in a plurality of independent elements so as to make the radiant heating device 2 more flexible and allow different levels of heating along the outer surface of the removable heating system 1 .

Preferably, the radiant heating device 2 further comprises a radiant heat insulation layer 9 arranged at the rear of the heating layer 3 allowing the reflection of the radiant heat initially radiating in the opposite direction to the passenger. This increases the amount of radiant heat towards the passenger. The radiant heat insulation layer 9 also makes it possible to increase the radiant heat transfer efficiency and advantageously has a mechanical resistance meeting aeronautical requirements including fire resistance.

In the example shown, the radiant heat insulation layer 9 is a metallic layer placed between the heating layer 3 and the rear protection layer 6.

A decorative layer 10 can be added to the front of the removable heating system 1 on the plastic shell 7.

In order to meet aeronautical constraints, the mechanical strength properties of the decorative surface 10 are preferably identical to the properties of the plastic shell 7 and of the means 8 for fixing the radiant heating device 2 to the plastic shell 7.

Like the plastic shell 7, the decorative surface 10 preferably has a sufficiently high thermal conductivity for effective heat transfer from the removable heating system 2 to a passenger and a mechanical strength meeting aeronautical requirements including fire resistance.

The decorative layer 10 preferably has a thermal inertia enabling it to reach a temperature high enough to provide thermal comfort to the passenger and low enough for the latter to be able to touch it without injury.

The thickness of the decorative layer 10 is preferably lower than the thickness of the plastic shell 7.

The removable heating system 1 also comprises removable fixing means 11 of the heating system 1 on a support.

The removable nature facilitates the certification of the removable heating system 1 which can be certified independently of the support on which it is fixed. In addition, the removable nature facilitates the maintenance of the removable heating system 1.

In the embodiment illustrated in , the removable heating system 1 is removably attached to a composite panel 12. The composite panel 12 comprises a flat surface 12a on which the removable heating system 1 is mounted.

In the example illustrated, the removable fixing means 11 comprise at least two attachment elements or fixing clips 11a and 11b extending from the inner surface 7b of the plastic shell 7.

Advantageously, the plastic shell 7 and the removable fastening means 11 can form a one-piece structure.

According to a variant, the removable fixing means 11 can comprise hook-and-loop fasteners that can be easily mounted and removed.

The radiant heater 2 fixed to the plastic shell 7 can be easily disassembled from its support by removing the plastic shell 7.

Preferably, the radiant heater 2 comprises a conductive heat insulation layer disposed behind the rear protective layer 6.

In the embodiment of the , the conductive heat insulating layer is a ventilation gap formed between the radiant heater 2 and the support which, in this example, is the composite panel 12.

The removable fixing means 11 of the removable heating system 1 can be configured to form the ventilation gap 13, in particular by adjusting the dimensions of the attachment elements 11a and 11b to form spacers.

The attachment elements 11a and 11b shown pass through the radiant heating device 2 and fix the assembly formed by the plastic shell 7 and the radiant heating device 2 on the composite panel 12.

The width of the ventilation gap 13 is sufficiently small, preferably less than 3 mm, so that no air flow is present in the ventilation gap 13. In this way, the insulation layer conductive heat limits the amount of conductive heat in the opposite direction to the passenger. Conductive heat is used to increase the temperature of the plastic shell 7 and increase the amount of radiant heat to the passenger and the radiant heat transfer efficiency.

Preferably, the removable fastening means 11 represent less than 10% of the space of the ventilation gap 13.

As a variant, the support can also have a different shape from a panel and be formed by a structure or a set of non-planar structures, for example formed from composite or metal.

In a second embodiment of the removable heating system referenced 14 illustrated in , the removable heating system 14 is fixed on a support formed by two structures 15a and 15b. The structures 15a and 15b are not parallel to the rear protective layer 6. The free space formed between the plastic shell 7 and the structures 15a, 15b is, in the example illustrated, greater than 5mm, outside the elements of hooks 11a and 11b, so that a flow of air can circulate between the radiant heating device 2 and the structures 15a, 15b. Given the air flow that circulates, the free space formed does not allow the formation of a conductive heat insulation layer.

Therefore, the radiant heater 16 shown in preferably further comprises a conductive heat insulation layer 17, disposed behind the rear protective layer 6.

The conductive heat insulation layer 17 may be an insulating foam.

Each of the hooking elements 11a and 11b is fixed to one of the structures 14a and 14b of the support.

One or more removable heating systems 1, 14 can be removably integrated into the seat of the aircraft seat assembly so that part of the seat forms a support.

The presence of removable heating systems 1, 14 makes it possible to compensate for the existence of perceived cold conditions coming from the overall air conditioning of the cabin generally left deliberately on low temperatures to reduce the risk of dizziness within the cabin of the aircraft.

In the example illustrated, the support is a structure located on a legrest unit 18 of a seat assembly of an aircraft cabin.

By aircraft seat assembly is meant an assembly comprising at least one aircraft cabin seat and which may include other structures in addition to the seat such as a legrest unit 18.

By legrest unit is meant a structure of the ottoman type allowing a passenger in a seated position on a seat to raise his legs by positioning them on the legrest unit 18. The legrest unit 18 is therefore, preferably placed in front of the seat.

According to one embodiment, the legrest unit 18 can be integrated into the rear part of the seat located in front. The aircraft seat assembly may then include the front seat.

As can be seen in Figures 5 and 6, the legrest unit 18 for aircraft seat assembly may include a legrest panel 19 on which the passenger can rest his legs and at least his feet.

The illustrated legrest unit 18 further comprises a recess 20 for the legs, delimited by at least one legrest panel 19 and an upper panel 21. The illustrated legrest panel 19 comprises an upper face 19a and a lower face (not visible) opposite the upper face 19a.

In the example shown, the recess 20 is also delimited by two side panels 22 and 23 so that the recess 20 and a rear panel (not visible) form a niche in the legrest unit 18.

A housing 24 for the passenger's feet can be provided between the legrest panel 19 and the ground allowing the passenger to position his feet on the ground, under the legrest panel 19.

In the upper part, the legrest unit 18 may comprise a front panel facing the passenger. The illustrated front panel has a lower front panel 25 and an upper front panel 26.

The lower front panel 25 can advantageously be inclined downwards so as to be oriented towards the legs of the passenger.

In one embodiment, the legrest unit 18 can integrate a screen 27, for example in the upper part, on the upper front panel 26, above the lower front panel 25.

One or more removable heating systems 1, 14 can be removably integrated into the legrest unit 18.

Conditioned air in the aircraft cabin may come from high areas such as a cabin roof and overhead baggage compartment and circulate to air outlets that may be arranged above the floor. In addition, the floor is the coldest place in the aircraft cabin, and existing heat sources such as those formed by the passengers themselves create upward convection of heat. As a result, hot air is trapped in high areas and low areas such as the floor and the passenger footwell 24 remain at lower temperatures.

In addition, the parts of the passenger's body in contact with padded areas of the seat, such as insulating foams, automatically heat these padded areas, so that a feeling of coldness of the passenger comes from these areas which are not in contact with the padded areas of the seat, in particular the feet, the legs and in particular the lower part of the legs, the hands and the arms.

The presence of removable heating systems 1 on the legrest unit 18 makes it possible to reach, advantageously, the lower parts of the passenger and, preferably, the segments of the body which are not in contact with the insulating foam of the seat. , so as to counter the feeling of cold perceived in the lower limbs and improve the thermal comfort of the passenger.

A passenger's lower body means the limbs of a seated passenger below the torso, including arms, hands, legs and feet.

With reference to the , at least one removable heating system 1, 14 can be arranged in a first zone 28, on the lower front panel 25, oriented towards the outside of the legrest unit 18, towards the passenger. The lower front panel 25 being inclined downwards, the removable heating system 1, 14 is oriented towards the lower parts of the passenger's body.

At least one removable heating system 1, 14 can also be arranged in a second zone 29, on an underside of the legrest panel arranged opposite the housing 24.

Preferably, as shown in , one or more removable heating systems 1, 14 can be arranged in a third zone 30, on the upper panel 21, opposite the recess 20.

In addition, at least one removable heating system 1, 14 can also be arranged in a fourth zone 31, on the ground, for example on the false floor of the aircraft cabin, opposite the housing 24 for the feet.

The positioning of at least one removable heating system 1, 14 in one of the first, second, third and fourth zones 28, 29, 30 and 31 makes it possible to reach the coldest parts of the passenger's body.

In order to create an enveloping heat zone, several removable heating systems 1, 14 can be arranged on the legrest unit 18.

The removable nature of the removable heating system 1, 14 allows it to be easily integrated on the legrest unit 18.

The removable heating system 1, 14 thus makes it possible to confer improved thermal comfort on the passenger, by non-intrusive radiant heating, combining high heat transfer efficiency, safety and compliance with aeronautical requirements.

Claims (13)

Removable heating system for aircraft, comprising:
- one or more radiant heating devices (2) each comprising:
a heating layer (3);
an electrode layer (4) comprising one or more anodes and one or more cathodes;
two front and rear protective layers (5, 6) arranged on either side of the assembly formed by the heating layer (3) and the layer of electrodes (4);
- a plastic shell (7) fixed on the front protective layer (5) of the radiant heater (2); And
- removable fixing means (11) of the removable heating system (1; 14) on a support (12; 15a, 15b). System according to Claim 1, in which the material of the front and rear protective layers (5, 6) is chosen from: polyimide, epoxy resin composite reinforced with FR-4 fiberglass, polyethylene terephthalate, or a polyurethane thermoplastic. System according to Claim 1 or 2, in which the material of the heating layer (3) is able to limit the temperature below a threshold value. A system according to any preceding claim, wherein the radiant heater (2) comprises a radiant heat insulation layer (9) disposed between the heating layer (3) and the rear protective layer (6). A system according to any preceding claim, wherein the radiant heater (2) comprises a conductive heat insulation layer (13; 17) disposed behind the rear protective layer (6). System according to any one of the preceding claims, in which the removable fixing means (11) of the removable heating system (1) are configured to form an air gap (13) between the radiant heating device (2) and the support (12; 15a, 15b). Legrest unit for an aircraft seat assembly, comprising a legrest panel (19) and at least one removable heating system (1; 14) according to any one of the preceding claims. Legrest unit according to claim 7, comprising a recess (20) for the legs of a passenger bounded by the legrest panel (19) and an upper panel (21), at least one removable heating system (1; 14) according to any one of claims 1 to 6 being disposed on the upper panel (21) facing the recess (20). Legrest unit according to Claim 7 or 8, comprising a housing (24) for the feet of a passenger delimited by the legrest panel (19) and the floor, and at least one removable heating system (1; 14 ) according to any one of claims 1 to 6 on an underside of the legrest panel (19) disposed facing said housing (24) and / or on the ground facing said housing (24). Legrest unit according to any one of Claims 7 to 9, comprising a front panel intended to be directed towards a passenger and inclined downwards, the front panel comprising at least one removable heating system (1; 14) according to the any of claims 1 to 6. Aircraft seat assembly comprising at least one heating system (1; 14) according to any one of claims 1 to 6. A seat assembly according to claim 11, comprising a legrest unit (18) according to any one of claims 7 to 10. Aircraft comprising at least one seat assembly according to claim 11 or 12.