Heat transfer arrangement

Abstract

A heat transfer arrangement includes a first component, a second component, a dynamic connection arrangement, a moveable thermal interface, and a thermally activated spacer arrangement. The first and second components are mechanically connected by the dynamic connection arrangement, which allows the first and second components to remain mechanically connected while allowing the spacing therebetween to vary. The moveable thermal interface allows transitioning between first and second interface configurations, and the moveable thermal interface thermally couples and decouples, respectively, the first and second components with respect to one another. The thermally activated spacer arrangement is: mechanically and thermally coupled to the first component; mechanically decoupled from the second component; mechanically coupled to the moveable thermal interface; transitionable between first and second spacer configurations responsive to a first component temperature transitioning across a predetermined threshold temperature, thereby causing the moveable thermal interface to concurrently transition between the first and second interface configurations.

Description

[0001] HEAT TRANSFER ARRANGEMENT

[0002] TECHNOLOGICAL FIELD

[0003] The present disclosure relates to heat transfer arrangements.

[0004] BACKGROUND

[0005] Removing generated heat from heat-producing devices, such as electronic devices, is well-known in the art. This is often conventionally achieved by providing a heat transfer arrangement, in which a hot object and a cold object or medium are placed in thermal conductive contact with one another, in order to allow heat dissipation. In some cases, it is possible for the cold object to become overheated via a different heat source, which could result in heat transfer in the opposite direction. Occasionally, it can be desirable to selectively thermally decouple the hot and cold objects, for example to prevent over-cooling of the hot object, or heat source.

[0006] Many examples of heat transfer arrangements are known in the art.

[0007] By way of non-limiting example, WO 2006 / 070121 discloses a system comprising an electronic device generating thermal energy and a radiator and capable of adopting two active and inactive configurations with the radiator in contact with or spaced apart from the electronic device. A thermal actuator comprising an element made of shape-memory alloy in the form of a spring controls the shift from the active configuration to the inactive configuration when the temperature in the vicinity of the device drops below a first predetermined threshold and from its inactive configuration to its active configuration when the temperature in the vicinity of the device rises above a second predetermined threshold.

[0008] Also by way of non-limiting example, US 9,080,820 discloses heat dissipation switches and systems, as well as their use for dissipating excess heat from a heat source. A heat dissipation switch may include a thermally isolating material having a number of conductive element cavities, within which a number of thermally switched conductive elements may nest either independently or as part of a thermally switched sheet. The material of the thermally switched conductive elements may be configured to deform in response to a temperature change through a threshold temperature or temperature range in order to create or interrupt heat flow paths from the heat source to a heat sink.

[0009] Also by way of non-limiting example, US 11,118,576 discloses a thermal actuator unit including a first member, a second member, an elastic part which is disposed between the first member and the second member, and a thermal deformation part which is disposed on a side of the first member opposite to a side with the second member and has a shape-memory alloy to be deformed to the side with the second member due to heat.

[0010] Also by way of non-limiting example, US 11,175,100 discloses a heat sink assembly comprising a heat sink and a shaping element made of a shape memory material, incorporated into the heat sink assembly in an assembly shape. An actuation energy can cause the shape memory material to change the shaping element to an actuation shape, and the actuation shape can produce a thermal coupling shape in the heat sink. Applying an actuation energy causes the shape memory material to change the shaping element from the assembly shape to the actuation shape to produce a thermal coupling shape in the heat sink.

[0011] Also by way of non-limiting example, Jiuming Ma et al (Experimental and theoretical studies of a thermal switch based on shape-memory alloy cladded with graphene paper, (Volume 42, 2020, Issue 7) discloses implementing a two-way memory alloy as a drive device for a thermal switch. Graphene paper was used to cover the surface of the memory alloy. Self-actuation of the shape-memory alloy and high thermal conductivity of graphene ostensibly enhance heat conduction of the switch.

[0012] GENERAL DESCRIPTION

[0013] According to a first aspect of the presently disclosed subject matter, there is provided a heat transfer arrangement comprising a first component, a second component, a dynamic connection arrangement, a moveable thermal interface and a thermally activated spacer arrangement: the first component and the second component being spaced apart from one another by a variable spacing, the first component and the second component being mechanically connected by the dynamic connection arrangement, the dynamic connection arrangement being configured for allowing the first component and the second component to remain mechanically connected while allowing said spacing to vary within a predetermined range; the moveable thermal interface being configured for transitioning between a first interface configuration and a second interface configuration, wherein in the first interface configuration, the moveable thermal interface thermally couples the first component and the second component to one another, and wherein in the second interface configuration, the movable thermal interface thermally decouples the first component and the second component from one another; the thermally activated spacer arrangement being mechanically and thermally coupled to the first component, and mechanically decoupled from the second component, the thermally activated spacer arrangement further being mechanically coupled to the moveable thermal interface; the thermally activated spacer arrangement being configured to transition between a first spacer configuration and a second spacer configuration responsive to a temperature of the first component transitioning across a predetermined threshold temperature, to thereby cause the moveable thermal interface to concurrently transition between the first interface configuration and the second interface configuration.

[0014] For example, in said first spacer configuration, the moveable thermal interface is in the first interface configuration, and wherein in said second spacer configuration, the moveable thermal interface is in the second interface configuration.

[0015] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured for causing the moveable thermal interface to transition from the first interface configuration to the second interface configuration responsive to the temperature of the first component increasing across the predetermined threshold temperature. Alternatively, for example, the thermally activated spacer arrangement is configured for causing the moveable thermal interface to transition from the first interface configuration to the second interface configuration responsive to the temperature of the first component decreasing across the predetermined threshold temperature. Additionally or alternatively, for example, the moveable thermal interface has a thermal conductivity of about 1000 W / m2K.

[0016] Additionally or alternatively, for example, the moveable thermal interface is fixed mechanically and thermally coupled to one of the first component and the second component, and wherein the moveable thermal interface is arranged to be selectively brought into and out of thermal coupling with the other of the first component and the second component. For example, the moveable thermal interface is flexible such as to permit extension towards and away from the other of the first component and the second component while remaining fixedly mechanically and thermally coupled to the one of the first component and the second component.

[0017] Additionally or alternatively, for example, the moveable thermal interface comprises at least one graphite sheet.

[0018] Additionally or alternatively, for example, the moveable thermal interface comprises a plurality of overlaid flexible graphite sheets arranged in a loop-shape having two loop halves, wherein the loop halves have respective first ends that are mechanically and coupled to the second component, and wherein the loop halves have respective second ends that are mechanically and thermally coupled to a terminal block, and wherein the terminal block is configured to project away from the one of the first component and second component to a range of projection distances.

[0019] Additionally or alternatively, for example, the moveable thermal interface comprises a flexible material supported by a support structure. For example, the support structure is mechanically coupled to the thermally activated spacer arrangement. For example, the support structure comprises a frame connected at a plurality of locations proximal to a perimeter of the support structure to a portion of the thermally activated spacer arrangement distal from the first component; wherein a central portion of the support structure within the perimeter is arranged to support a central portion of the moveable thermal interface, so that movement of the support structure causes movement of the central portion of the moveable thermal interface, so as to permit the moveable thermal interface to thermally couple and decouple the first and second components. Additionally or alternatively, for example, the moveable thermal interface permits the first component and the second component to remain thermally coupled across the full range of variable spacing therebetween, and wherein the moveable thermal interface permits the first component and the second component to be thermally decoupled across the full range of the variable spacing.

[0020] Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a first geometrical configuration in the first spacer configuration and a second geometrical configuration in the second spacer configuration, wherein the first and second geometrical configurations are different from one another; wherein responsive to a change in temperature of the first component across the predetermined threshold temperature, the geometric form of the thermally activated spacer arrangement is configured to change between the first geometrical configuration and the second geometrical configuration. For example, in a transverse direction between the first component and the second component, the thermally activated spacer arrangement has a greater length dimension in the second spacer configuration than in the first spacer configuration. Alternatively, for example, in a transverse direction between the first component and the second components, the thermally activated spacer arrangement has a greater length dimension in the first spacer configuration than in the second spacer configuration. Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a shape memory alloy. For example, the shape memory alloy comprises a nickel-titanium (nitinol) alloy. For example, the nickel-titanium alloy comprises 49.8% Nickel. Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a multilayer metallic structure.

[0021] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured to expand in a direction away from the first component when a temperature of the thermally activated spacer rises above the predetermined threshold temperature. For example, the predetermined threshold temperature is a first predetermined threshold temperature, and wherein the thermally activated spacer arrangement is further configured to contract in a direction towards the first component when a temperature of the thermally activated spacer falls below a second predetermined threshold temperature. For example, the first predetermined threshold temperature is the same as the second predetermined threshold temperature. Alternatively, for example, the first predetermined threshold temperature is greater than the second predetermined threshold temperature.

[0022] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured to contract in a direction towards the first component when a temperature of the thermally activated spacer falls below the predetermined threshold temperature. For example, the predetermined threshold temperature is a first predetermined threshold temperature, and wherein the thermally activated spacer arrangement is further configured to expand in a direction away from the first component when a temperature of the thermally activated spacer rises above a second predetermined threshold temperature. For example, the first predetermined threshold temperature is the same as the second predetermined threshold temperature. Alternatively, for example, the first predetermined threshold temperature is lower than the second predetermined threshold temperature.

[0023] Additionally or alternatively, for example, the predetermined threshold temperature is about 80°C.

[0024] Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a plurality of separate spacers comprising a first geometrical configuration in the first spacer configuration and a second geometrical configuration in the second spacer configuration, wherein the first and second geometrical configurations are different from one another; wherein responsive to a change in temperature of the first component across the predetermined threshold temperature, the geometric form of the separate spacers is configured to change between the first geometrical configuration and the second geometrical configuration.

[0025] Additionally or alternatively, for example, the thermally activated spacer comprises a plurality of blocks of shape memory alloy having a first end mechanically and thermally coupled to the first component and an opposite second end mechanically connected to the moveable thermal interface; wherein a change in temperature of the first component across the predetermined threshold causes the plurality of blocks of shape memory alloy to expand away from or contract towards the first component, such that the second end, and the moveable thermal interface mechanically coupled thereto, moves away from or towards the first component respectively. Additionally or alternatively, for example, the first component operates as a heat sink and the second component operates as a heat source. Alternatively, for example, the first component operates as a heat source and the second component operates as a heat sink.

[0026] Additionally or alternatively, for example, one of the first component and the second component comprises a portion of an aircraft fuselage skin, and the other one of the first component and the second component comprises an electronic device configured to generate heat in use.

[0027] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured to be spaced from the second component.

[0028] Additionally or alternatively, for example, the dynamic connection arrangement comprises a damping arrangement configured to maintain a mechanical non-zero spacing between the first and second components while allowing relative movement of the components towards and away from one another within a predetermined range. For example, the damping arrangement comprises at least one damper including any one of hydraulic, pneumatic, torsion, compression spring and extension spring dampers.

[0029] According to a second aspect of the presently disclosed subject matter there is provided a heat transfer arrangement comprising a first component, a dynamic connection arrangement, a moveable thermal interface and a thermally activated spacer arrangement: the first component configured to be mechanically connected by the dynamic connection arrangement to a second component, the first component and the second component configured to be spaced apart from one another by a variable spacing, the dynamic connection arrangement being configured for allowing the first component and the second component to remain mechanically connected while allowing said spacing to vary within a predetermined range; the moveable thermal interface being configured for transitioning between a first interface configuration and a second interface configuration, wherein in the first interface configuration, the moveable thermal interface is configured to thermally couple the first component and the second component to one another, and wherein in the second interface configuration, the movable thermal interface is configured to thermally decouple the first component and the second component from one another; the thermally activated spacer arrangement being mechanically and thermally coupled to the first component, and configured to be mechanically decoupled from the second component, the thermally activated spacer arrangement further being mechanically coupled to the moveable thermal interface; the thermally activated spacer arrangement being configured to transition between a first spacer configuration and a second spacer configuration responsive to a temperature of the first component transitioning across a predetermined threshold temperature, to thereby cause the moveable thermal interface to concurrently transition between the first interface configuration and the second interface configuration.

[0030] For example, in said first spacer configuration, the moveable thermal interface is in the first interface configuration, and wherein in said second spacer configuration, the moveable thermal interface is in the second interface configuration.

[0031] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured for causing the moveable thermal interface to transition from the first interface configuration to the second interface configuration responsive to the temperature of the first component increasing across the predetermined threshold temperature. Alternatively, for example, the thermally activated spacer arrangement is configured for causing the moveable thermal interface to transition from the first interface configuration to the second interface configuration responsive to the temperature of the first component decreasing across the predetermined threshold temperature.

[0032] Additionally or alternatively, for example, the moveable thermal interface has a thermal conductivity of about 1000 W / m2K.

[0033] Additionally or alternatively, for example, the moveable thermal interface is fixedly mechanically and configured to be thermally coupled to one of the first and second components, and is arranged to be selectively brought into and out of thermal coupling with the other of the first and second components. For example, the moveable thermal interface is flexible so as to permit extension towards and away from the other of the first and second components while remaining fixedly mechanically and thermally coupled to the one of the first and second components.

[0034] Additionally or alternatively, for example, the moveable thermal interface comprises at least one graphite sheet.

[0035] Additionally or alternatively, for example, the moveable thermal interface comprises a plurality of overlaid flexible graphite sheets arranged in a loop-shape having two loop halves, wherein the loop halves have respective first ends that are mechanically and coupled to the second component, and wherein the loop halves have respective second ends that are mechanically and thermally coupled to a terminal block, and wherein the terminal block is configured to project away from the one of the first component and second component to a range of projection distances.

[0036] Additionally or alternatively, for example, the moveable thermal interface comprises a flexible material supported by a support structure. For example, the support structure is mechanically coupled to the thermally activated spacer arrangement. For example, the support structure comprises a frame connected at a plurality of locations proximal to a perimeter of the support structure to a portion of the thermally activated spacer arrangement distal from the first component; wherein a central portion of the support structure within the perimeter is arranged to support a central portion of the moveable thermal interface, so that movement of the support structure causes movement of the central portion of the moveable thermal interface, configured so as to permit the moveable thermal interface to thermally couple and decouple the first and second components.

[0037] Additionally or alternatively, for example, the moveable thermal interface is configured to permit the first and second components to remain thermally coupled across the full range of variable spacing therebetween, and is configured to permit the first and second components to be thermally decoupled across the full range of the variable spacing.

[0038] Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a first geometrical configuration in the first spacer configuration and a second geometrical configuration in the second spacer configuration, wherein the first and second geometrical configurations are different from one another; wherein responsive to a change in temperature of the first component across the predetermined threshold temperature, the geometric form of the thermally activated spacer arrangement is configured to change between the first geometrical configuration and the second geometrical configuration. For example, in a transverse direction between the first and second components, the thermally activated spacer arrangement has a greater length dimension in the first spacer configuration than in the second spacer configuration. Alternatively, for example, in a transverse direction between the first and second components, the thermally activated spacer arrangement has a greater length dimension in the second spacer configuration than in the first spacer configuration. Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a multilayer metallic structure. Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a shape memory alloy. For example, the shape memory alloy comprises a nickel-titanium (nitinol) alloy. For example, the nickeltitanium alloy comprises 49.8% Nickel.

[0039] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured to expand in a direction away from the first component when a temperature of the thermally activated spacer rises above the predetermined threshold temperature. For example, the predetermined threshold temperature is a first predetermined threshold temperature, and wherein the thermally activated spacer arrangement is further configured to contract in a direction towards the first component when a temperature of the thermally activated spacer falls below a second predetermined threshold temperature. For example, the first predetermined threshold temperature is the same as the second predetermined threshold temperature. Alternatively, for example, the first predetermined threshold temperature is greater than the second predetermined threshold temperature.

[0040] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured to contract in a direction towards the first component when a temperature of the thermally activated spacer falls below the predetermined threshold temperature. For example, the predetermined threshold temperature is a first predetermined threshold temperature, and wherein the thermally activated spacer arrangement is further configured to expand in a direction away from the first component when a temperature of the thermally activated spacer rises above a second predetermined threshold temperature. For example, the first predetermined threshold temperature is the same as the second predetermined threshold temperature. For example, the first predetermined threshold temperature is lower than the second predetermined threshold temperature.

[0041] Additionally or alternatively, for example, the predetermined threshold temperature is about 80°C.

[0042] Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a plurality of separate spacers comprising a first geometrical configuration in the first spacer configuration and a second geometrical configuration in the second spacer configuration, wherein the first and second geometrical configurations are different from one another; wherein responsive to a change in temperature of the first component across the predetermined threshold temperature, the geometric form of the separate spacers is configured to change between the first geometrical configuration and the second geometrical configuration.

[0043] Additionally or alternatively, for example, the thermally activated spacer comprises a plurality of blocks of shape memory alloy having a first end mechanically and thermally coupled to the first component and an opposite second end mechanically connected to the moveable thermal interface; wherein a change in temperature of the first component across the predetermined threshold causes the plurality of blocks of shape memory alloy to expand away from or contract towards the first component, such that the second end, and the moveable thermal interface mechanically coupled thereto, moves away from or towards the first component respectively.

[0044] Additionally or alternatively, for example, the first component comprises a heat sink and the second component comprises a heat source. Alternatively, for example, the first component comprises a heat source and the second component comprises a heat sink.

[0045] Additionally or alternatively, for example, one of the first component and the second component comprises an aircraft fuselage skin, and the other of the first component and the second component comprises an electronic device configured to generate heat in use. Additionally or alternatively, for example, the thermally activated spacer arrangement is configured to be spaced from the second component.

[0046] Additionally or alternatively, for example, the dynamic connection arrangement comprises a damping arrangement configured to maintain a mechanical non-zero spacing between the first and second components while allowing relative movement of the components towards and away from one another within a predetermined range. For example, the damping arrangement comprises at least one damper from among the group of hydraulic, pneumatic, torsion, compression spring and extension spring dampers.

[0047] According to a third aspect of the presently disclosed subject matter there is provided a heat transfer arrangement comprising a dynamic connection arrangement, a moveable thermal interface and a thermally activated spacer arrangement: the dynamic connection arrangement configured to mechanically connect a first component to a second component, the first component and the second component being configured to be spaced apart from one another by a variable spacing, the dynamic connection arrangement being configured for allowing the first component and the second component to remain mechanically connected while allowing said spacing to vary within a predetermined range; the moveable thermal interface being configured for transitioning between a first interface configuration and a second interface configuration, wherein in the first interface configuration, the moveable thermal interface is configured to thermally couple the first component and the second component to one another, and wherein in the second interface configuration, the movable thermal interface is configured to thermally decouple the first component and the second component from one another; the thermally activated spacer arrangement configured to be mechanically and thermally coupled to the first component, and configured to be mechanically decoupled from the second component, the thermally activated spacer arrangement further being mechanically coupled to the moveable thermal interface; the thermally activated spacer arrangement being configured to transition between a first spacer configuration and a second spacer configuration responsive to a temperature of the first component transitioning across a predetermined threshold temperature, to thereby cause the moveable thermal interface to concurrently transition between the first interface configuration and the second interface configuration.

[0048] For example, in said first spacer configuration, the moveable thermal interface is in the first interface configuration, and wherein in said second spacer configuration, the moveable thermal interface is in the second interface configuration.

[0049] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured for causing the moveable thermal interface to transition from the first interface configuration to the second interface configuration responsive to the temperature of the first component increasing across the predetermined threshold temperature. Alternatively, for example, the thermally activated spacer arrangement is configured for causing the moveable thermal interface to transition from the first interface configuration to the second interface configuration responsive to the temperature of the first component decreasing across the predetermined threshold temperature.

[0050] Additionally or alternatively, for example, the moveable thermal interface has a thermal conductivity of about 1000 W / m2K.

[0051] Additionally or alternatively, for example, the moveable thermal interface is fixedly mechanically and configured to be thermally coupled to one of the first and second components, and is arranged to be selectively brought into and out of thermal coupling with the other of the first and second components. For example, the moveable thermal interface is flexible so as to permit extension towards and away from the other of the first and second components while remaining fixedly mechanically and thermally coupled to the one of the first and second components.

[0052] Additionally or alternatively, for example, the moveable thermal interface comprises at least one graphite sheet.

[0053] Additionally or alternatively, for example, the moveable thermal interface comprises a plurality of overlaid flexible graphite sheets arranged in a loop-shape having two loop halves, wherein the loop halves have respective first ends that are mechanically and coupled to the second component, and wherein the loop halves have respective second ends that are mechanically and thermally coupled to a terminal block, and wherein the terminal block is configured to project away from the one of the first component and second component to a range of projection distances.

[0054] Additionally or alternatively, for example, the moveable thermal interface comprises a flexible material supported by a support structure. For example, the support structure is mechanically coupled to the thermally activated spacer arrangement. For example, the support structure comprises a frame connected at a plurality of locations proximal to a perimeter of the support structure to a portion of the thermally activated spacer arrangement configured to be distal from the first component; wherein a central portion of the support structure within the perimeter is arranged to support a central portion of the moveable thermal interface, so that movement of the support structure causes movement of the central portion of the moveable thermal interface, configured so as to permit the moveable thermal interface to thermally couple and decouple the first and second components.

[0055] Additionally or alternatively, for example, the moveable thermal interface is configured to permit the first and second components to remain thermally coupled across the full range of variable spacing therebetween, and is configured to permit the first and second components to be thermally decoupled across the full range of the variable spacing.

[0056] Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a first geometrical configuration in the first spacer configuration and a second geometrical configuration in the second spacer configuration, wherein the first and second geometrical configurations are different from one another; wherein responsive to a change in temperature of the first component across the predetermined threshold temperature, the geometric form of the thermally activated spacer arrangement is configured to change between the first geometrical configuration and the second geometrical configuration. For example, in a movement direction between the first and second components, the thermally activated spacer arrangement has a greater length dimension in the first spacer configuration than in the second spacer configuration. Alternatively, for example, in a movement direction between the first and second components, the thermally activated spacer arrangement has a greater length dimension in the second spacer configuration than in the first spacer configuration.

[0057] Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a multilayer metallic structure.

[0058] Alternatively, for example, the thermally activated spacer arrangement comprises a shape memory alloy. For example, the shape memory alloy comprises a nickel-titanium (nitinol) alloy. For example, the nickel-titanium alloy comprises 49.8% Nickel.

[0059] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured to expand in a direction configured to be away from the first component when a temperature of the thermally activated spacer rises above the predetermined threshold temperature. For example, the predetermined threshold temperature is a first predetermined threshold temperature, and wherein the thermally activated spacer arrangement is further configured to contract in a direction configured to be towards the first component when a temperature of the thermally activated spacer falls below a second predetermined threshold temperature. For example, the first predetermined threshold temperature is the same as the second predetermined threshold temperature. Alternatively, for example, the first predetermined threshold temperature is greater than the second predetermined threshold temperature.

[0060] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured to contract in a direction configured to be towards the first component when a temperature of the thermally activated spacer falls below the predetermined threshold temperature. For example, the predetermined threshold temperature is a first predetermined threshold temperature, and wherein the thermally activated spacer arrangement is further configured to expand in a direction configured to be away from the first component when a temperature of the thermally activated spacer rises above a second predetermined threshold temperature. For example, the first predetermined threshold temperature is the same as the second predetermined threshold temperature. Alternatively, for example, the first predetermined threshold temperature is lower than the second predetermined threshold temperature. Additionally or alternatively, for example, the predetermined threshold temperature is about 80°C.

[0061] Additionally or alternatively, for example, the thermally activated spacer arrangement comprises a plurality of separate spacers comprising a first geometrical configuration in the first spacer configuration and a second geometrical configuration in the second spacer configuration, wherein the first and second geometrical configurations are different from one another; wherein responsive to a change in temperature of the first component across the predetermined threshold temperature, the geometric form of the separate spacers is configured to change between the first geometrical configuration and the second geometrical configuration.

[0062] Additionally or alternatively, for example, the thermally activated spacer comprises a plurality of blocks of shape memory alloy having a first end configured to be mechanically and thermally coupled to the first component and an opposite second end mechanically connected to the moveable thermal interface; wherein a change in temperature of the first component across the predetermined threshold causes the plurality of blocks of shape memory alloy to expand in a direction configured to be away from or contract in a direction configured to be towards the first component, such that the second end, and the moveable thermal interface mechanically coupled thereto, moves away from or towards the first component respectively.

[0063] Additionally or alternatively, for example, the first component comprises a heat sink and the second component comprises a heat source. Alternatively, for example, the first component comprises a heat source and the second component comprises a heat sink.

[0064] Additionally or alternatively, for example, one of the first component and the second component comprises an aircraft fuselage skin, and the other of the first component and the second component comprises an electronic device configured to generate heat in use.

[0065] Additionally or alternatively, for example, the thermally activated spacer arrangement is configured to be spaced from the second component.

[0066] Additionally or alternatively, for example, the dynamic connection arrangement comprises a damping arrangement configured to maintain a mechanical non-zero spacing between the first and second components while allowing relative movement of the components towards and away from one another within a predetermined range. For example, the damping arrangement comprises at least one damper from among the group of hydraulic, pneumatic, torsion, compression spring and extension spring dampers.

[0067] BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, examples will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0069] Fig. 1 shows a top isometric view of an example of a heat transfer arrangement;

[0070] Fig. 2 shows a front view of the example of Fig. 1 in a thermally coupled configuration;

[0071] Fig. 3 shows a front view of the example of Fig. 1 in a thermally decoupled configuration;

[0072] Fig. 4 shows an enlargement of the portion of Fig. 3 encircled by a broken line;

[0073] Fig. 5A schematically illustrates the example of Fig. 1 in a thermally decoupled configuration; Fig. 5B schematically illustrates the example of Fig. 5A in a thermally coupled configuration;

[0074] Fig. 6A schematically illustrates another example of a heat transfer arrangement in a thermally decoupled configuration; Fig. 6B schematically illustrates the example of Fig. 6A in a thermally coupled configuration;

[0075] Fig. 7A schematically illustrates another example of a heat transfer arrangement in a thermally decoupled configuration; Fig. 7B schematically illustrates the example of Fig. 7A in a thermally coupled configuration;

[0076] Fig. 8A schematically illustrates another example of a heat transfer arrangement in a thermally decoupled configuration; and Fig. 8B schematically illustrates the example of Fig. 8A in a thermally coupled configuration. DETAILED DESCRIPTION

[0077] Throughout the description and accompanying figures, like features are denoted by like reference signs.

[0078] Referring to Fig. 1, Fig. 2, Fig. 3, and Fig. 4, a first example of a heat transfer arrangement, according to a first aspect of the presently disclosed subject matter, is generally designated 100, and comprises a first component 110, a second component 120, a dynamic connection arrangement 130, a moveable thermal interface 140 and a thermally activated spacer arrangement 150.

[0079] The heat transfer arrangement 100 is configured to selectively and alternately provide thermal coupling and thermal decoupling between the first component 110 and the second component 120, as will described below in more detail.

[0080] By "thermal coupling", is meant thermal or heat conductive coupling, whereby there is significant heat transfer (i.e., significant transfer of thermal energy) via thermal conduction between two or more adjacent objects or components in direct physical and thermal conductive contact with one another. Optionally, indirect physical contact between two components, whereby there is physical contact between the two components indirectly via one or more intervening (non-gaseous) heat-conducting elements to form a physically connected sequence, is considered to permit thermal conduction. Conversely, by "thermal decoupling", is meant heat conductive decoupling, whereby there is no thermal contact or conduction between the respective components, even though there could still be convective heat transfer and / or radiative heat transfer between the respective components. In this regard, physical disconnection (thereby providing an absence of heat conductive physical contact between the two components) would thermally decouple two components.

[0081] In the context of the presently disclosed subject matter, heat transfer between the first component and second component is considered to be predominantly via heat conduction, and the effects of heat transfer via convection and / or radiation are conserved to be negligible. Thus, in this context, "thermal coupling" herein refers exclusively to heat conduction thermal coupling via direct (or indirect via an intervening heat-conductive element, as described above) physical contact between the respective heat exchange surfaces, while "thermal decoupling" refers exclusively to an absence of direct heat conduction and an absence of direct physical heat-conductive contact between the respective heat exchange surfaces.

[0082] Referring in particular to Fig. 2, the first component 110 and the second component 120 are spaced apart from one another by a variable spacing S. The first component 110 and the second component 120 are mechanically connected together via the dynamic connection arrangement 130. The dynamic connection arrangement 130 is configured for allowing the first component 110 and the second component 120 to remain mechanically connected while allowing said variable spacing S to vary within a predetermined range.

[0083] For example, the heat transfer arrangement 100 can be used in applications in which there is an expectation of the heat transfer arrangement 100 being subjected to transient and / or dynamic loads. For example, in applications in which the heat transfer arrangement 100 is carried by a moving vehicle, for example an aircraft, the heat transfer arrangement 100 can be subjected to vibrations, accelerations, decelerations, turbulence and the like, caused as the vehicle or aircraft experiences vibrations, oscillations, accelerations, decelerations, and so on. The dynamic connection arrangement 130 allows the corresponding relative movement between the first component 110 and the second component 120, caused as a result of the aforementioned transient and / or dynamic loads, to be dampened, and limits relative movement between the first and second components 110, 120, within the predetermined of the variable spacing S.

[0084] By "mechanically connected" or "mechanically coupled", is meant herein to refer to a direct physical connection between two mechanically solid components via interconnecting mechanical surfaces that are in physical contact with one another, directly or via a solid intervening element (which can be considered to be part of one or the other of the two components), such as to thereby permit transfer of loads between the two components via the interconnecting mechanical surfaces, including static and / or dynamic loads, for example tensile or compressive loads. Conversely, "mechanically disconnected" or "mechanically decoupled" is meant herein to refer to a converse situation, in which the two components are not in direct physical contact with one another directly or indirectly, for example an air gap separates the mechanical surfaces, and no mechanical loads can therefore be transferred between the two components via the mechanical surfaces.

[0085] In at least this example, the first component 110 and the second component lie generally parallel to one another, subject to relative movement therebetween within the aforesaid range of spacing S, as described above. The first component 110 has a first thermal transfer surface 112 and the second component 120 has a second thermal transfer surface 122. The first thermal transfer surface 112 and the second thermal transfer surface 122 face one another, separated by a gap having said variable spacing S.

[0086] In at least this example, the variable spacing S can vary, and is always greater than zero.

[0087] The dynamic connection arrangement 130 allows for relative movement between the first component 110 and the second component along a transverse or movement axis MA parallel to the spacing S, and limits such movement within the aforesaid predetermined range of spacing S.

[0088] In at least this example, the dynamic connection arrangement 130 comprises four dampers 132, each having a first end 134 mechanically connected to the first component 110 and a second opposite end 136 mechanically connected to the second component. The dampers 132 are configured to reduce and limit vibration and relative movement between the first component 110 and the second component 120 to within a certain range only, such as to define the aforesaid predetermined range of spacing S.

[0089] In at least this example, the second component 120 is supported by two support beams 124, arranged under the second component 120 at opposite edges thereof. Other arrangements are of course possible.

[0090] In at least this example, each support beam 124 has a first end 124a and a second end 124b, each of the first end 120a and the second end 124b being mechanically connected to a respective second end 136 of one of the dampers 132. Accordingly, the second component 120 is mechanically coupled to the dampers 132 via the support beams 124. The dampers 132 are each configured for dampening corresponding relative movement between the first component 110 and the second component 120, caused as a result of the aforementioned transient and / or dynamic loads, and for limiting relative movement between the first and second components 110, 120, within the predetermined of the variable spacing S.

[0091] For example, the dampers 132 can be configured as any one of mechanical dampers, pneumatic dampers, hydraulic dampers, or a combination of such dampers, and / or can include any other kind of suitable damper known to the skilled person.

[0092] The dampers 132 have a relatively low thermal conductivity as compared with the thermal conductivity of the first component 110 or of the second component 120, such as to prevent significant thermal heat transfer via the dampers 132. For example, the thermal conductivity of the first component 110 or of the second component 120 can be at least twice the thermal conductivity of the dampers 132. Thus the dampers 132 are considered herein essentially as thermally insulating intervening elements between the first component 110 and the second component 120.

[0093] For example, the dampers 132 can have a heat transfer coefficient in the order of about 500 W / m2K.

[0094] The dynamic connection arrangement 130 allows the first component 110 and the second component 120 to remain mechanically connected while allowing the spacing S in between to vary within a predetermined range. The mechanical connection between the first component 110 and the second component 120 is independent of the first component 110 and the second component 120 being mutually thermally coupled or thermally decoupled.

[0095] The moveable thermal interface 140 is configured for transitioning between a first interface configuration ICi (illustrated in Fig. 2 for example) and a second interface configuration IC2 (illustrated in Fig. 3 and Fig. 4 for example).

[0096] In the first interface configuration ICi, the moveable thermal interface 140 thermally couples the first component 110 and the second component 120 to one another, thereby allowing heat transfer via heat conduction to be established between the first component 110 and the second component 120. In the second interface configuration IC2, the movable thermal interface 140 thermally decouples the first component 110 and the second component 120 from one another, thereby not allowing heat transfer via heat conduction to occur between the first component 110 and the second component 120.

[0097] The moveable thermal interface 140, in operation of the heat transfer arrangement 100, operates such as:

[0098] - in the first interface configuration ICi, to cause the first and second components 110, 120 to remain thermally coupled across the full range of variable spacing S therebetween; or, alternately

[0099] - in the second interface configuration IC2, to cause the first and second components 110, 120 to become thermally decoupled across the full range of the variable spacing S, depending on operational mode of the thermally activated spacer arrangement 150, as will become clearer herein.

[0100] In at least this example, the moveable thermal interface 140 is fixedly coupled, mechanically and thermally, to the second component 120, and the moveable thermal interface 140 is arranged to be selectively and alternately brought into and out of thermal coupling with the first component 110, corresponding to the first interface configuration ICi and the second interface configuration IC2, respectively.

[0101] In at least this example, the moveable thermal interface 140 is mechanically flexible, or otherwise movable or deformable, so as to permit extension of the moveable thermal interface 140 towards and away from the first component 110, along the movement axis MA, while remaining fixed mechanically and thermally coupled to the second component 120.

[0102] Thus, the moveable thermal interface 140 is configured for enabling a spacing dimension thereof (parallel to movement axis MA) to vary such as to accommodate the full range of dynamic movement (as allowed by the dynamic connection arrangement 130) when in the first interface configuration ICi, and such as to accommodate the full range of dynamic movement (as allowed by the dynamic connection arrangement 130) when in the second interface configuration IC2. It is to be noted that in the first interface configuration ICi, the moveable thermal interface 140 is also in direct physical contact with the first component 110 to thereby allow the thermal coupling therebetween.

[0103] In at least this example, the moveable thermal interface 140 comprises a plurality of overlaid flexible graphite sheets 141, arranged in a loop-shape having essentially two loop halves 148. The loop halves 148 of graphite sheets 141 have respective first ends 142a 142b, collectively referred to as first ends 142, that are mechanically and thermally coupled to the thermal transfer surface 122 of the second component 120. The loop halves 148 of graphite sheets 141 have respective second ends 143a 143b, collectively referred to as second ends 143, that are mechanically and thermally coupled to a terminal block 149. Extending between each of the first ends 142a, 142b and the respective second ends 143a, 143b is a respective central sheet portion 144 of the graphite sheets 141. The terminal block 149 thus essentially projects away from the thermal transfer surface 122 of the second component 120 and towards the thermal transfer surface 112 of the first component 110 via the two loop halves 148.

[0104] For example, such graphite sheets 141 can include PGS (Panasonic Graphite Sheets) provided by Panasonic (Japan).

[0105] By "loop shape" or "loop-shape", what is meant is formed into a curve subtending at least 180°. For example, a full or partial circle, obround, oval, ellipse or other curved shape. The loop-shape can be a closed loop provided entirely by the graphite sheets 141, or can be an open loop connected and closed across the opening in the open loop by the thermal transfer surface 122 of the second component 120.

[0106] The loop-shape of the moveable thermal interface 140 is elastically deformable and flexible, so as to be able to change form reversibly, to be extended towards or retracted away from the thermal transfer surface 112 of the first component 110, by changing a geometric configuration of the loop-shape. The central sheet portions 144 are thus configured to project away from the second component 120 within a range of projection distances. In this way the moveable thermal interface 140 can selectively thermally couple and decouple the second component 120 and the first component 110 together, by mechanically moving the terminal block 149 into and out of contact with the first component 110. In at least this example, and as shown in Fig. 2, a support structure 146 is provided, configured to support the moveable thermal interface 140, particularly the terminal block 149 that is thermally and mechanically connected to the flexible central sheet portions 144 of the graphite sheets 141, such that movement of the support structure 146 causes movement of the terminal block 149, so as to permit the moveable thermal interface 140 to thermally couple and decouple the first and second components 110, 120.

[0107] Thus, in at least this example, the terminal block 149 that is thermally and mechanically connected to the support structure 146, and both move as single unit towards and away from the first component 110 in operation of the heat transfer arrangement 100.

[0108] In at least this example, the support structure 146 comprises a frame connected to a portion of the thermally activated spacer arrangement 150 distal from the first component 110, at a plurality of locations proximal to a perimeter of the support structure 146. A central portion of the support structure 146 within the perimeter of the support structure 146 is arranged to support the terminal block 149.

[0109] The support structure 146 in at least this example is in the form of an inverted top- hat in the view shown in Fig. 2, formed from a flat plate bent into a U-shaped structure, having a central portion 148 projecting downwards and two flanges 147 at opposite ends thereof.

[0110] The central portion 148 and the flanges 147 of the support structure 146 lie in planes generally parallel to, and spaced from and disposed between, the first component 110 and second component 120. As shown in Fig. 2, the central portion 148 of the U- shaped structure of the support structure 146 projects generally orthogonally from the plane in which the flanges 147 lie, towards a generally parallel plane closer to the first component 110 than the plane in which the flanges 147 lie.

[0111] The central portion 148 of the support structure 146 provides a supportive and heat transfer surface 149, lying in a plane generally parallel to the thermal transfer surface 112 of the first component 110, configured to mechanically support the terminal block 149. The supportive and heat transfer surface 149 also facilitates heat transfer between the central sheet portions 144 of the loop of graphite sheets 141 and the first component 110 via the terminal block 149, when there is thermal coupling, i.e. conductive thermal coupling, therebetween. The support structure 146 has first surface 146a and a second surface 146b separated by a through-thickness t. The first surface 146a faces the thermal transfer surface 122 of the second component 120, and the second surface 146b faces the thermal transfer surface 112 of the first component 110. The through-thickness t is relatively small as compared with spacing S, to enable easy transfer of heat therethrough, and the thermal conductivity of the support structure is for example in the order of about 1000 W / m2K.

[0112] The support structure 146 is relatively less flexible than the graphite sheets 141 of the loop-shaped moveable thermal interface 140, so that each of the loop-halves 148 of graphite sheets 141 is capable of extending towards or contracting away from the first component 110 with movement of the support structure 146, which essentially behaves as a relative rigid body. Accordingly, movement of the support structure 146 is capable of bringing the terminal block 149 of the moveable thermal interface 140 into and out of thermal coupling with the first component 110.

[0113] The thermally activated spacer arrangement 150 is mechanically and thermally coupled to the first component 110, and at least in this example is always mechanically decoupled from the second component 120, as best seen in Fig. 1. In at least this example, the thermally activated spacer arrangement is configured to be spaced from the second component 120 in a direction parallel to movement axis MA.

[0114] The thermally activated spacer arrangement 150 is spaced from the second component 120, so as to prevent thermal coupling of the first and second components 110, 120 via the thermally activated spacer arrangement 150, and to avoid any effect on the geometrical configuration (as will be described further below) of the thermally activated spacer arrangement 150 due to otherwise thermal coupling between the thermally activated spacer arrangement 150 and the second component 120.

[0115] The thermally activated spacer arrangement 150 is also mechanically coupled to the moveable thermal interface 140, via fixings between the flanges 147 of the support structure 146 and the thermally activated spacer arrangement 150, as will be described in further detail below.

[0116] The thermally activated spacer arrangement 150 is configured to transition between a first spacer configuration SCi and a second spacer configuration SC2 responsive to a first temperature Ti of the first component 110 transitioning across a predetermined threshold temperature TTI, to thereby cause the moveable thermal interface 140 to concurrently transition between the first interface configuration ICi and the second interface configuration IC2.

[0117] Thus, the first spacer configuration SCi corresponds to the first interface configuration ICi, and the second spacer configuration SC2 corresponds to the second interface configuration IC2.

[0118] In at least this example, the thermally activated spacer arrangement 150 comprises a first geometrical configuration in the first spacer configuration SCi and a second geometrical configuration in the second spacer configuration SC2. The first geometrical configuration and second geometrical configuration are different from one another. In particular, the first geometrical configuration and second geometrical configuration represent different length dimensions of the thermally activated spacer arrangement 150 in a direction parallel to the movement axis MA.

[0119] Responsive to a change in the first temperature Ti of the first component 110 across the predetermined threshold temperature TTI, the geometric form of the thermally activated spacer arrangement 150 is configured to change between the first geometrical configuration and the second geometrical configuration, thereby changing the thermally activated spacer arrangement 150 between the first spacer configuration SCi and the second spacer configuration SC2.

[0120] In a direction parallel to the movement axis MA between the first and second components 110, 120, more particularly, between the first and second thermal transfer surfaces 112, 122 respectively, the thermally activated spacer arrangement 150 has a first length dimension LDi in the first spacer configuration SCi (Fig. 1), and a second length dimension LD2 in the second spacer configuration SC2 (Fig. 2), wherein the second length dimension LD2 is greater than the first length dimension LDi.

[0121] In the first spacer configuration SCi, a distal end 156 of the thermally activated spacer arrangement 150 distal from the first component 110 is at a first spacing Xi from the first thermal transfer surface 112 of the first component 110, corresponding to first length dimension LDi, measured in a direction parallel to movement axis MA. In the second spacer configuration SC2, the distal end 156 of the thermally activated spacer arrangement 150 distal from the first component 100 is at a second spacing X2 from the first thermal transfer surface 112 of the first component 110 corresponding to the second spacer configuration SC2, measured in a direction parallel to movement axis MA. The first spacing Xi is smaller than the second spacing X2.

[0122] The thermally activated spacer arrangement 150 comprises, in at least this example, at two extendible elements 152, each having a respective first longitudinal end, or proximal end 152, mechanically anchored and thermally coupled to the first component 110, and a respective second longitudinal end, or the distal end 156, mechanically connected to the terminal block 149 of the moveable thermal interface 140, via the support structure 146.

[0123] In at least this example, each flange 147 of the support structure 146 comprises a through-bore, through which a fixing such as a screw, bolt or the like 153 passes, fixing the support structure 146 to the distal end 156 of each extendible element 152 of the thermally activated spacer arrangement 150. A Belleville washer can be provided threaded on a fixing at the first surface of the respective flange 147.

[0124] In at least some examples, the thermally activated spacer arrangement comprises a plurality of individual spacers, for example, but not limited to, a plurality of blocks of shape memory metal alloy.

[0125] In at least this example, each of the extendible elements 152 comprises a respective block of a shape memory alloy 153. A change in the first temperature Ti of the first component 110 across the predetermined threshold temperature TTI causes each of the blocks 132 of shape memory alloy to expand away from the first component 110, in a direction towards the second component 120 along the movement axis MA, such that the second end 156 moves away from the first component 110, carrying the support structure 146 with the second end 156, causing the terminal block 149 of the moveable thermal interface 140 that is mechanically coupled to the support structure 146 via the support structure 146, to move away from the first component 110.

[0126] This expansion provides the change in the geometrical configurations from the first length dimension LDi to the second length dimension LD2. The shape memory alloy in at least this example comprises a nickel titanium alloy (Nitinol), for example in which the percentage of Nickel is 49.8%, configured to transition to an austenitic crystal structure when a temperature of the shape memory alloy rises above a first predetermined threshold temperature TTI, and to transition to a martensitic crystal structure when a temperature of the shape memory alloy falls below a second predetermined temperature TT2. Due to hysteresis, the first predetermined threshold temperature TTI is higher than the second predetermined threshold temperature TT2.

[0127] In at least this example, the first predetermined threshold temperature TTI is 80°C.

[0128] Many examples of suitable Nitinol shape memory alloys are well known and commercially available.

[0129] Since the thermally activated spacer arrangement 150 is mechanically and thermally coupled to the first component 110, the thermally activated spacer arrange 150 is considered to be in thermal equilibrium with, and thus nominally at the same first temperature Ti as, the portion of the first component 110 to which it is mechanically and thermally connected, and thus the thermally activated spacer arrangement 150 is sensitive to, and can be responsive to, changes in the aforesaid first temperature Ti.

[0130] Moreover, since the thermally activated spacer arrangement 150 is mechanically coupled to the moveable thermal interface 140, mechanical loads can be transferred therebetween. Consequently, responsive to the first temperature Ti of the first component 110 transitioning across the predetermined threshold temperature TTI, the thermally activated spacer arrangement 150 transitions between the first spacer configuration SCi and the second spacer configuration SC2, thereby expanding from the first length dimension LDi to the second length dimension LD2, thereby carrying the support structure 146 (and the terminal block 149) in a direction away from the first component 110, and thereby causing the moveable thermal interface 140 to mechanically disconnect from the first component 110, and to thereby thermally decouple the first component 110 and the second component 120 from one another.

[0131] According to the above aspect of the presently disclosed subject matter, the ability of the first component 110 and the second component 120 to be thermally coupled is dependent on the magnitude of the first temperature Ti of the first component (viz-a-viz the threshold temperature TTI), which passively determines the configuration of the thermally activated spacer arrangement 150, and which in turn transitions the configuration of the moveable thermal interface 140 between a thermally coupled or a thermally decoupled configuration of the first and second components 110, 120.

[0132] In at least this example, the first spacer configuration SCi corresponds to the respective martensitic crystalline structure of the shape memory alloy blocks 153, and the second spacer configuration SC2 corresponds to the respective austenitic crystalline structure of the shape memory alloy blocks 153.

[0133] The first predetermined threshold temperature TTI, or transition temperature at which the configuration of the spacer will transition from the first spacer configuration SCi to the second spacer configuration SC2, is a temperature in a range of 70°C to90°C, for example a temperature of about 80°C. This transition corresponds to expansion or extension of the blocks 153 in a direction towards the second component 120 along the movement axis MA, and correspondingly, transition of the first component 110 and the second component 120 from a thermally coupled configuration to a thermally decoupled configuration, i.e. from being in a configuration permitting conductive heat transfer to a configuration precluding conductive heat transfer.

[0134] The second predetermined threshold temperature TT2, or transition temperature at which the configuration of the spacer will transition from the second spacer configuration SC2 to the first spacer configuration SCi is a temperature less than the first predetermined threshold temperature TTI. This transition corresponds to retraction or contraction of the blocks 152 in a direction away from the second component 120 along the movement axis MA and correspondingly, transition of the first component 110 and the second component 120 from a thermally decoupled configuration to a thermally coupled configuration, i.e. from being in a configuration precluding conductive heat transfer to a configuration permitting conductive heat transfer.

[0135] In at least this example, the moveable thermal interface 140 has a relatively high thermal conductivity compared to the thermal conductivity of the thermally activated spacer arrangement 150 and of the dynamic connection arrangement 130. For example, the moveable thermal interface 140 can have a thermal conductivity of for example about 1000W / m2K, whereas the thermally activated spacer arrangement 150 and / or the dynamic connection arrangement 130 can have a much lower thermal conductivity, for example around 500W / m2K. Accordingly, heat is significantly transferred via the moveable thermal interface 140 which is relatively thermally conducting, whereas no significant heat transfer occurs via the dynamic connection arrangement 130 which are relatively thermally insulating.

[0136] In at least some applications of at least this example, for at least part of the duration of the operation of the respective heat transfer arrangement, the first component 110 is relatively cold and the second component 120 is relatively hot. This can be achieved, for example, by the first component 110 being part of the fuselage skin of an aircraft, or alternatively by the first component 110 being mechanically and thermally coupled to an aircraft fuselage via an intervening thermally conducting medium, and the second component 120 being, or being mechanically and thermally coupled to, an electronic device, for example, which in use thereof generates unwanted heat.

[0137] However, other external thermal sources, for example the Sun, can heat the aircraft fuselage (or first component 110) to a temperature higher than that of the second component 120, such that continued thermal coupling of the first and second components 110, 120 would be expected to result in thermal conduction from the first component 110 towards the second components 120, rather than in the opposite, desired, direction, leading to a heating of the second component 120 via the first component 110, rather than cooling. The resulting eventual overheating of the second component could damage the second component, for example if the second component is an electronic device or the like, for example. Therefore, thermal decoupling of the first component 110 and the second component 120 from one another when the first temperature Ti of the first component 110 exceeds the first predetermined threshold temperature TTI can prevent reverse-direction heat transfer and in at least some examples also prevent associated damage to the second component, for example.

[0138] It at least some examples, the first predetermined threshold temperature TTI can be in the range of about 70°C to about 100°C, optionally about 85°C to about 95°C, further optionally about 80°C. Furthermore, it is to be noted that thermal recoupling of the first component 110 and the second component 120 to one another when the first temperature Ti of the first component 110 falls below the second predetermined threshold temperature TT2 can ensure renewed heat dissipation where possible without damage to the second component 120, in which heat is transferred to the first component 110 from the second component 120.

[0139] It at least some examples, the second predetermined threshold temperature TT2 can be in the range of about 40°C to about 80°C, optionally between about 50°C to about 75°C, further optionally about 70°C.

[0140] In at least some other applications of at least this example, for at least part of a duration of the operation of the respective heat transfer arrangement, the second component 120 is relatively cold and the first component 110 is relatively hot. This can be achieved, for example, by the second component 120 being, or being mechanically and thermally coupled to, an aircraft fuselage and the first component 110 being, or being mechanically and thermally coupled to, an electronic device which in use generates heat.

[0141] The operation of the heat transfer arrangement 100 will now be described according to an example.

[0142] Referring in particular to Figs. 2 and 5B, at first temperatures Ti of the first component 110 which are below the second predetermined threshold temperature T2, or due to hysteresis, at first temperatures Ti which have not risen above the first predetermined threshold temperature TTI, the crystalline structure of the respective shape memory alloy blocks 153 (which are thermally and mechanically connected to the first component 110) are in the respective martensite structure. The shape memory alloy blocks 153 are correspondingly in the first spacer configuration SCi, wherein the shape memory alloy blocks 153 are in a relatively contracted state towards the first component 110, i.e., at the first spacing Xi or first length dimension LDi. Consequently, the support structure 146, which is mechanically connected to the respective extendible elements 152, is in a relatively close position to, and in thermal contact with, the first component 110. In this manner, the moveable thermal interface 140 is maintained in a first interface configuration ICi, in which the moveable thermal interface 140 thermally couples the first component 110 and the second component 120 to one another. When the thermally activated spacer arrangement 150 is in the first spacer configuration SCi, the moveable thermal interface is in the first interface configuration ICi. As the first temperature Ti of the first component 110 rises across the first predetermined threshold temperature TTI (in at least this example, as the first temperature Ti of the first component 110 exceeds the first predetermined threshold temperature TTI), the crystalline structure of the shape memory alloy blocks 152 (which are thermally and mechanically connected to the first component 110) changes from martensite to austenite, and the shape memory alloy blocks 153 expand in a direction away from the first component 110, into the second spacer configuration SC2. This causes the second ends 156 of the extendible elements 152 to move away from the first component 110, moving the flanges 147, and thereby the support structure 146, away from the first component 110. In turn, the support structure 146 causes the moveable thermal interface 140, to transition from the first interface configuration ICi, in which the moveable thermal interface 140 thermally couples the first component 110 and the second component 120 to one another, to the second interface configuration IC2, in which the movable thermal interface 140 thermally decouples the first component 110 and the second component 120 from one another. The second interface configuration IC2 and the second spacer configuration SC2 are shown in Figs. 3, 4 and 5 A. The crystalline structure of the shape memory alloy blocks 152 (which are thermally and mechanically connected to the first component 110) will subsequently remain in the austenitic crystalline state, until the first temperature Ti of the first component 110 drops below the second predetermined threshold temperature TT2. When the thermally activated spacer arrangement 150 is in the second spacer configuration SC2, the moveable thermal interface is in the second interface configuration IC2.

[0143] In at least this example, decoupling in the second interface configuration takes place by the terminal block 149 being moved away from the first component 110 by the support structure 146 being pushed upwards (as seen in the view of Fig. 2, for example) by the expanding shape memory alloy blocks 153 of the extendible elements 152, while still thermally coupled to the second component 120. However, in an at least some alternative variations of these examples, the respective support structure can be arranged, for example but without limitation, through a suitable mechanism, to separate the loop shaped movable thermal interface 140 from both the first component 110 and the second component 120 when the first temperature Ti of the first component 110 rises above the first predetermined threshold temperature TTI, and conversely to couple the loop shaped movable thermal interface 140 to both the first component 110 and the second component 120 when the first temperature Ti of the first component 110 falls below the second predetermined threshold temperature TT2.

[0144] As the first temperature Ti of the first component drops from above the first threshold temperature TTI, down below the second threshold temperature TT2, the crystalline structure of the shape memory alloy blocks 153 of the extendible elements 152 (which are thermally and mechanically connected to the first component 110) changes from austenite to martensite, and the shape memory alloy blocks 153, and thus the extendible elements 152, can contract in a direction towards the first component 110, reverting back to the first spacer configuration SCi. This causes the second ends 156 of the shape memory alloy blocks 153 and thus of the extendible elements 152 to move back towards the first component 110, moving the flanges 147, and consequently the support structure 146, towards the first component 110. In turn, the support structure 146 causes the moveable thermal interface 140, to concurrently transition from the second interface configuration IC2, in which the moveable thermal interface 140 thermally decouples the first component 110 and the second component 120 from one another, to the first interface configuration ICi, in which the movable thermal interface 140 thermally couples the first component 110 and the second component 120 to one another. The first interface configuration ICi and the first spacer configuration SCi are shown in Figs. 2 and 5B. The crystalline structure of the shape memory alloy blocks 153, and thus the extendible elements 152 (which are thermally and mechanically connected to the first component 110) will subsequently remain in the martensitic crystalline state, until once again the first temperature Ti of the first component 110 rises above the first predetermined threshold temperature TTI.

[0145] In at least this example, the thermally activated spacer arrangement 150 comprises biasing elements, for example springs 158, that urge the extendible elements 152 to the first spacer configuration SCi when the shape memory alloy blocks 153 change to the respective martensitic crystalline structure from the respective austenitic crystalline structure. However, in at least some alternative variations of this example, the respective shape memory alloy blocks 153 can be configured for providing the so-called two-way shape memory effect (TWSME), in which the respective Nitinol is programmed with two memory shapes - a first memory shape corresponding to the first spacer configuration SCi, and a second memory shape corresponding to the second spacer configuration SC2, and the respective shape memory alloy blocks 153 causes the respective extendible elements 152 to transition between the respective first spacer configuration SCi and the respective second spacer configuration SC2, in either direction, without the need for any biasing elements.

[0146] According to another aspect of the presently disclosed subject matter the heat transfer arrangement includes all the features of, and operates in a similar manner to, the first example, mutatis mutandis, with the difference that the first component is absent from the respective heat transfer arrangement per se. According to this aspect, the first component is not part per se of the heat transfer arrangement, and rather the respective heat transfer arrangement is instead configured to be attached to the respective first component, in the manner described for the first example, for example but without limitation, a vehicle body, fuselage or the like where the vehicle body, fuselage or the like. Thus, according to this aspect of the presently disclosed subject matter the heat transfer arrangement is provided as a unit without the first component.

[0147] According to another aspect of the presently disclosed subject matter the heat transfer arrangement includes all the features of, and operates in a similar manner to, the first example, mutatis mutandis, with the difference that the first component and the second component are absent from the respective heat transfer arrangement per se. According to this aspect, the first component and the second component are not part per se of the heat transfer arrangement, and rather the respective heat transfer arrangement is provided, comprising the dynamic connection arrangement, the moveable thermal interface and the thermally activated spacer arrangement, and is configured to be connected to first component, in the manner described for the first example, mutatis mutandis, for example but without limitation, a vehicle body, fuselage or the like where the vehicle body, fuselage or the like, and further configured to be attached to second component, in the manner described for the first example, mutatis mutandis, for example but without limitation, an electronic device configured, at least in operation, to generate heat.

[0148] An alternative variation of the first example of Figs. 1 to 5B includes all the features of, and operates in a similar manner to, the first example, mutatis mutandis, with the following difference. The respective moveable thermal interface is not mechanically coupled to the second component, but rather mechanically coupled only to the thermally activated spacer arrangement via a mechanical linkage, such as an alternative support structure, configured, for example with a pincer-type arrangement, configured to compress the moveable interface so as to thermally decouple the thermal interface from both the first and second component when the temperature of the first component rises above the first threshold temperature Ti, and to allow the moveable interface to expand so as to be thermally coupled to both the first and second component when the temperature of the first component falls below the second threshold temperature T2.

[0149] Another alternative variation of the first example of Figs. 1 to 5B, is illustrated schematically in Figs. 6A and 6B, and includes all the features of, and operates in a similar manner to, the first example, mutatis mutandis, with the following difference.

[0150] In the example of Figs. 6A and 6B, the respective thermally activated spacer arrangement 130 is configured for causing the moveable thermal interface 140 to transition from the first interface configuration ICi to the second interface configuration IC2 (from thermal coupling to thermal decoupling of the first and second components) responsive to the temperature Ti of the respective first component 110 (effectively a heat sink) decreasing across the predetermined threshold temperature TTI. This arrangement could help prevent damage to the electronic device, or second component 120, by overcooling, which could, for example but without limitation, take place in an outer-space- type scenario.

[0151] Further, the thermally activated spacer arrangement 130 of the example of Figs. 6A and 6B is configured for causing the respective moveable thermal interface 140 to transition from the second interface configuration IC2 to the first interface configuration ICi (from thermal decoupling to thermal coupling of the first and second components) responsive to the temperature Ti of the first component 110 increasing across a predetermined threshold temperature TT2 greater than the predetermined threshold temperature TTI.

[0152] In a direction along the respective movement axis MA between the first and second components 110, 120, more particularly, between the first and second thermal transfer surfaces 112, 122 respectively of the first and second components 110, 120, the thermally activated spacer arrangement has a greater length dimension in the second spacer configuration SC2 than in the first spacer configuration SCi.

[0153] This arrangement allows heat transfer to take place, as long as the respective first component 110 (heat sink) is not too cold as compared with the respective second component 120.

[0154] While in the previous examples, the thermally activated spacer arrangement 130 has a contracted configuration along the respective movement axis MA between the first and second components 110, 120 at lower temperatures and an expanded configuration along the movement axis MA at higher temperatures, in the present example, the opposite is the case. This can be achieved for example by configuring the shape memory allow to have a particular shape in each of the austenite and martensite configurations, or by mechanically inverting the relationship between the respective biasing elements 158 and the respective shape memory alloy blocks 153 with respect to the respective moveable thermal interface 140, while still maintaining thermal communication between the first component 110 and the respective shape memory alloy blocks 153. Another alternative variation is comparable to this example mutatis mutandis, except that the moveable thermal interface 140 is mechanically and thermally coupled to the first component 110, with the support structure 146 having an inverted configuration compared to the above examples. The thermally activated spacer arrangement 130 has a contracted configuration along the respective movement axis MA between the first and second components 110, 120 at lower temperatures and an expanded configuration along the movement axis MA at higher temperatures. Accordingly, when the temperature Ti of the first component 110 (effective heat sink) rises above the first predetermined threshold temperature TTI, the thermally activated spacer arrangement 130 is expanded, so as to bring the moveable thermal interface 140 into thermal coupling with the second component 120. When the temperature Ti of the first component 110 (effective heat sink) falls below the second predetermined threshold temperature TT2, which is lower than the first predetermined threshold temperature TTI, the thermally activated spacer arrangement 130 is contracted, so as to provide a separation between the moveable thermal interface 140 and the second component 120, thereby thermally decoupling the first and second components 110, 120 from one another. This arrangement also allows heat transfer to take place, as long as the respective first component 110 (effective heat sink) is not too cold as compared with the respective second component 120.

[0155] Yet another alternative variation of the first example of Figs. 1 to 5B, is illustrated schematically in Figs. 7A and 7B, and includes all the features of, and operates in a similar manner to, the first example, mutatis mutandis, with the following difference.

[0156] In the example of Figs. 7A and 7B, the respective first component 110 generates heat (effectively behaving as a heat source), whereas the second component 120 dissipates heat (effectively behaving as a heat sink). The respective thermally activated spacer arrangement 130 is configured for causing the respective moveable thermal interface 140 to transition from the respective first interface configuration ICi to the respective second interface configuration IC2 (from thermal coupling to thermal decoupling of the respective first and second components 110, 120) responsive to the temperature Ti of the first component 110 increasing across the predetermined threshold temperature TTI.

[0157] Further, the respective thermally activated spacer arrangement 130 is configured for causing the respective moveable thermal interface 140 to transition from the respective second interface configuration IC2 to the respective first interface configuration ICi (from thermal decoupling to thermal coupling of the first and second components 110, 120) responsive to the temperature Ti of the first component decreasing across a second predetermined threshold temperature TT2 less than the predetermined threshold temperature TTI. This arrangement allows heat transfer (i.e., via heat conduction) to take place from the first component 110 to the second component 120, as long as the first component 110 (effectively a heat source) is not too hot as compared with the second component 120. This can prevent damage to, the second component 120 which effectively acts as a heat sink.

[0158] Yet another alternative variation of the first example of Figs. 1 to 5B, is illustrated schematically in Figs. 8 A and 8B, and includes all the features of, and operates in a similar manner to, the first example, mutatis mutandis, with the following difference.

[0159] In the example of Figs. 8A and 8B, the first component 110 generates heat (effectively behaving as a heat source), whereas the second component 120 dissipates heat (effectively behaving as a heat sink). The respective thermally activated spacer arrangement 130 is configured for causing the respective moveable thermal interface 140 to transition from the respective first interface configuration ICi to the respective second interface configuration IC2 (from thermal coupling to thermal decoupling of the first and second components 110, 120) responsive to the temperature Ti of the first component decreasing across the first predetermined threshold temperature TTI.

[0160] Further, the respective thermally activated spacer arrangement 130 is configured for causing the respective moveable thermal interface 140 to transition from the respective second interface configuration IC2 to the respective first interface configuration ICi (from thermal decoupling to thermal coupling of the first and second components 110, 120) responsive to the respective temperature Ti of the of the first component increasing across a second predetermined threshold temperature TT2 greater than the first predetermined threshold temperature TTI.

[0161] In a direction along the movement axis MA between the respective first and second components 110, 120, more particularly, between the respective first and second thermal transfer surfaces 112, 122 respectively, the respective thermally activated spacer arrangement has a greater extent in the first spacer configuration SCi than in the second spacer configuration SC2.

[0162] This arrangement allows heat transfer (via heat conduction) to take place from the first component 110 to the second component 120, when the temperature of the first component 110 (the effective heat source) gets too hot, and prevents accidental overcooling of the first component 110 (effective heat source) when the first component 110 is too cold by decoupling the first and second components 110, 120, which could, for example but without limitation, take place in an outer-space-type scenario.

[0163] In the present example, the thermally activated spacer arrangement 130 has an expanded configuration along the movement axis MA between the first and second components 110, 120 at lower temperatures and a contracted configuration along the respective movement axis MA at higher temperatures. This can be achieved by configuring the shape memory allow to have a particular shape in each of the austenite and martensite configurations for example, or by mechanically inverting the relationship between the respective biasing elements 158 and the respective shape memory alloy blocks 153 with respect to the respective moveable thermal interface 140, while still maintaining thermal communication between the first component 110 and the respective shape memory alloy blocks 153.

[0164] Another alternative variation is comparable to this example mutatis mutandis, except that the moveable thermal interface 140 is mechanically and thermally coupled to the first component 110, with the support structure 146 having an inverted configuration compared to the above examples. The thermally activated spacer arrangement 130 has a contracted configuration along the respective movement axis MA between the first and second components 110, 120 at lower temperatures and an expanded configuration along the movement axis MA at higher temperatures. Accordingly, when the temperature Ti of the first component 110 (effective heat source) rises above the first predetermined threshold temperature TTI, the thermally activated spacer arrangement 130 is expanded, so as to bring the moveable thermal interface 140 into thermal coupling with the second component 120. When the temperature Ti of the first component 110 (effective heat source) falls below the second predetermined threshold temperature TT2, which is lower than the first predetermined threshold temperature TTI, the thermally activated spacer arrangement 130 is contracted, such as to provide a separation between the moveable thermal interface 140 and the second component 120, thereby thermally decoupling the first and second components 110, 120 from one another. This arrangement also allows heat transfer (via heat conduction) to take place from the first component 110 to the second component 120, when the temperature of the first component 110 (the effective heat source) gets too hot, and prevents accidental over-cooling of the first component 110 (effective heat source) when the first component 110 is too cold by decoupling the first and second components 110, 120.

[0165] Yet another alternative variation of the first example of Figs. 1 to 8B includes all the features of, and operates in a similar manner to, any one of the foregoing examples, mutatis mutandis, with the difference that the moveable thermal interface is fixedly mechanically and thermally coupled to the first component, and is arranged to be selectively brought into and out of thermal coupling with the other of the first and second components. Additionally or alternatively, the arrangements of the respective moveable thermal interface 140 and / or the respective thermally activated spacer 150 can be reversed, so as to be associated with the respective second component mutatis mutandis instead of the respective first component, and to be associated with the respective first component mutatis mutandis instead of the respective second component.

[0166] Yet another alternative variation of the first example of Figs. 1 to 8B includes all the features of, and operates in a similar manner to, any one of the foregoing examples, mutatis mutandis, with the difference that instead of the use of a shape memory material, a multilayer metallic structure is used, for example a bimetallic strip or multi-metallic plate, as the respective thermally active spacer arrangement 150, configured to change its geometric form responsive to the temperature of the first or second component 110 to which it is mechanically and thermally coupled.

[0167] Yet another alternative variation of the first example of Figs. 1 to 8B includes all the features of, and operates in a similar manner to, any one of the foregoing examples, mutatis mutandis, with the difference that the respective thermally active spacer arrangement 150 comprises a material with no hysteresis curve in its geometric transition temperatures, such that the first predetermined threshold temperature TTI is the same as the second predetermined threshold temperature TT2.

[0168] It should be noted that the word “comprising” as used throughout the appended claims is to be interpreted to mean “including but not limited to”.

[0169] While there has been shown and disclosed examples in accordance with the presently disclosed subject matter, it will be appreciated that many changes may be made therein without departing from the scope of the presently disclosed subject matter as set out in the claims.

Claims

CLAIMS:

1. A heat transfer arrangement comprising a first component, a second component, a dynamic connection arrangement, a moveable thermal interface, and a thermally activated spacer arrangement: the first component and the second component being spaced apart from one another by a variable spacing, the first component and the second component being mechanically connected by the dynamic connection arrangement, the dynamic connection arrangement being configured for allowing the first component and the second component to remain mechanically connected while allowing said spacing to vary within a predetermined range; the moveable thermal interface being configured for transitioning between a first interface configuration and a second interface configuration, wherein in the first interface configuration, the moveable thermal interface thermally couples the first component and the second component to one another, and wherein in the second interface configuration, the movable thermal interface thermally decouples the first component and the second component from one another; the thermally activated spacer arrangement being mechanically and thermally coupled to the first component, and mechanically decoupled from the second component, the thermally activated spacer arrangement further being mechanically coupled to the moveable thermal interface; the thermally activated spacer arrangement being configured to transition between a first spacer configuration and a second spacer configuration responsive to a temperature of the first component transitioning across a predetermined threshold temperature, to thereby cause the moveable thermal interface to concurrently transition between the first interface configuration and the second interface configuration.

2. The heat transfer arrangement according to claim 1, wherein in said first spacer configuration, the moveable thermal interface is in the first interface configuration, and wherein in said second spacer configuration, the moveable thermal interface is in the second interface configuration.

3. The heat transfer arrangement according to any one of claims 1 to 2, wherein the thermally activated spacer arrangement is configured for causing the moveable thermal interface to transition from the first interface configuration to the second interface configuration responsive to the temperature of the first component increasing across the predetermined threshold temperature.

4. The heat transfer arrangement according to any one of claims 1 to 2, wherein the thermally activated spacer arrangement is configured for causing the moveable thermal interface to transition from the first interface configuration to the second interface configuration responsive to the temperature of the first component decreasing across the predetermined threshold temperature.

5. The heat transfer arrangement according to any one of claims 1 to 4, wherein the moveable thermal interface has a thermal conductivity of about 1000 W / m2K.

6. The heat transfer arrangement according to any one of claims 1 to 5, wherein the moveable thermal interface is fixed mechanically and thermally coupled to one of the first component and the second component, and wherein the moveable thermal interface is arranged to be selectively brought into and out of thermal coupling with the other of the first component and the second component.

7. The heat transfer arrangement according to claim 6, wherein the moveable thermal interface is flexible such as to permit extension towards and away from the other of the first component and the second component while remaining fixedly mechanically and thermally coupled to the one of the first component and the second component.

8. The heat transfer arrangement according to any one of claims 1 to 7, wherein the moveable thermal interface comprises at least one graphite sheet.

9. The heat transfer arrangement according to any one of claims 1 to 7, wherein the moveable thermal interface comprises a plurality of overlaid flexible graphite sheets arranged in a loop-shape having two loop halves, wherein the loop halves have respective first ends that are mechanically and coupled to the second component, and wherein the loop halves have respective second ends that are mechanically and thermally coupled toa terminal block, and wherein the terminal block is configured to project away from the one of the first component and second component to a range of projection distances.

10. The heat transfer arrangement according to any one of claims 1 to 9, wherein the moveable thermal interface comprises a flexible material supported by a support structure.

11. The heat transfer arrangement according to claim 10, wherein the support structure is mechanically coupled to the thermally activated spacer arrangement.

12. The heat transfer arrangement according to claim 11, wherein the support structure comprises a frame connected at a plurality of locations proximal to a perimeter of the support structure to a portion of the thermally activated spacer arrangement distal from the first component; wherein a central portion of the support structure within the perimeter is arranged to support a central portion of the moveable thermal interface, so that movement of the support structure causes movement of the central portion of the moveable thermal interface, so as to permit the moveable thermal interface to thermally couple and decouple the first and second components.

13. The heat transfer arrangement according to any one of claims 1 to 12, wherein the moveable thermal interface permits the first component and the second component to remain thermally coupled across the full range of variable spacing therebetween, and wherein the moveable thermal interface permits the first component and the second component to be thermally decoupled across the full range of the variable spacing.

14. The heat transfer arrangement according to any one of claims 1 to 13, wherein the thermally activated spacer arrangement comprises a first geometrical configuration in the first spacer configuration and a second geometrical configuration in the second spacer configuration, wherein the first and second geometrical configurations are different from one another; wherein responsive to a change in temperature of the first component across the predetermined threshold temperature, the geometric form of the thermally activated spacer arrangement is configured to change between the first geometrical configuration and the second geometrical configuration.

15. The heat transfer arrangement according to claim 14, wherein in a transverse direction between the first component and the second component, the thermally activated spacer arrangement has a greater length dimension in the second spacer configuration than in the first spacer configuration.

16. The heat transfer arrangement according to claim 14, wherein in a transverse direction between the first component and the second components, the thermally activated spacer arrangement has a greater length dimension in the first spacer configuration than in the second spacer configuration.

17. The heat transfer arrangement according to any one of claims 14 to 16, wherein the thermally activated spacer arrangement comprises a shape memory alloy.

18. The heat transfer arrangement according to claim 17, wherein the shape memory alloy comprises a nickel-titanium (nitinol) alloy.

19. The heat transfer arrangement according to claim 18, wherein the nickel-titanium alloy comprises 49.8% Nickel.

20. The heat transfer arrangement according to any one of claims 14 to 16, wherein the thermally activated spacer arrangement comprises a multilayer metallic structure.

21. The heat transfer arrangement according to any one of claims 14 to 20, wherein the thermally activated spacer arrangement is configured to expand in a direction away from the first component when a temperature of the thermally activated spacer rises above the predetermined threshold temperature.

22. The heat transfer arrangement according to claim 21, wherein the predetermined threshold temperature is a first predetermined threshold temperature, and wherein the thermally activated spacer arrangement is further configured to contract in a direction towards the first component when a temperature of the thermally activated spacer falls below a second predetermined threshold temperature.

23. The heat transfer arrangement according to claim 22, wherein the first predetermined threshold temperature is the same as the second predetermined threshold temperature.

24. The heat transfer arrangement according to claim 22, wherein the first predetermined threshold temperature is greater than the second predetermined threshold temperature.

25. The heat transfer arrangement according to any one of claims 14 to 20, wherein the thermally activated spacer arrangement is configured to contract in a direction towards the first component when a temperature of the thermally activated spacer falls below the predetermined threshold temperature.

26. The heat transfer arrangement according to claim 25, wherein the predetermined threshold temperature is a first predetermined threshold temperature, and wherein the thermally activated spacer arrangement is further configured to expand in a direction away from the first component when a temperature of the thermally activated spacer rises above a second predetermined threshold temperature.

27. The heat transfer arrangement according to claim 26, wherein the first predetermined threshold temperature is the same as the second predetermined threshold temperature.

28. The heat transfer arrangement according to claim 26, wherein the first predetermined threshold temperature is lower than the second predetermined threshold temperature.

29. The heat transfer arrangement according to any one of claims 1 to 28, wherein the predetermined threshold temperature is about 80°C.

30. The heat transfer arrangement according to any one of claims 14 to 29, wherein the thermally activated spacer arrangement comprises a plurality of separate spacers comprising a first geometrical configuration in the first spacer configuration and a second geometrical configuration in the second spacer configuration, wherein the first and second geometrical configurations are different from one another; wherein responsive to achange in temperature of the first component across the predetermined threshold temperature, the geometric form of the separate spacers is configured to change between the first geometrical configuration and the second geometrical configuration.

31. The heat transfer arrangement according to any one of claims 1 to 30, wherein the thermally activated spacer comprises a plurality of blocks of shape memory alloy having a first end mechanically and thermally coupled to the first component and an opposite second end mechanically connected to the moveable thermal interface; wherein a change in temperature of the first component across the predetermined threshold causes the plurality of blocks of shape memory alloy to expand away from or contract towards the first component, such that the second end, and the moveable thermal interface mechanically coupled thereto, moves away from or towards the first component respectively.

32. The heat transfer arrangement according to any one of claims 1 to 31, wherein the first component operates as a heat sink and the second component operates as a heat source.

33. The heat transfer arrangement according to any one of claims 1 to 31, wherein the first component operates as a heat source and the second component operates as a heat sink.

34. The heat transfer arrangement according to any one of claims 1 to 31, wherein one of the first component and the second component comprises a portion of an aircraft fuselage skin, and the other one of the first component and the second component comprises an electronic device configured to generate heat in use.

35. The heat transfer arrangement according to any one of claims 1 to 34, wherein the thermally activated spacer arrangement is configured to be spaced from the second component.

36. The heat transfer arrangement according to any one of claims 1 to 35, wherein the dynamic connection arrangement comprises a damping arrangement configured to maintain a mechanical non-zero spacing between the first and second components whileallowing relative movement of the components towards and away from one another within a predetermined range.

37. The heat transfer arrangement according to claim 36, wherein the damping arrangement comprises at least one damper including any one of hydraulic, pneumatic, torsion, compression spring and extension spring dampers.

38. A heat transfer arrangement comprising a first component, a dynamic connection arrangement, a moveable thermal interface, and a thermally activated spacer arrangement: the first component configured to be mechanically connected by the dynamic connection arrangement to a second component, the first component and the second component configured to be spaced apart from one another by a variable spacing, the dynamic connection arrangement being configured for allowing the first component and the second component to remain mechanically connected while allowing said spacing to vary within a predetermined range; the moveable thermal interface being configured for transitioning between a first interface configuration and a second interface configuration, wherein in the first interface configuration, the moveable thermal interface is configured to thermally couple the first component and the second component to one another, and wherein in the second interface configuration, the movable thermal interface is configured to thermally decouple the first component and the second component from one another; the thermally activated spacer arrangement being mechanically and thermally coupled to the first component, and configured to be mechanically decoupled from the second component, the thermally activated spacer arrangement further being mechanically coupled to the moveable thermal interface; the thermally activated spacer arrangement being configured to transition between a first spacer configuration and a second spacer configuration responsive to a temperature of the first component transitioning across a predetermined threshold temperature, to thereby cause the moveable thermal interface to concurrently transition between the first interface configuration and the second interface configuration.

39. The heat transfer arrangement according to claim 38, wherein in said first spacer configuration, the moveable thermal interface is in the first interface configuration, andwherein in said second spacer configuration, the moveable thermal interface is in the second interface configuration.

40. The heat transfer arrangement according to any one of claims 38 to 39, wherein the thermally activated spacer arrangement is configured for causing the moveable thermal interface to transition from the first interface configuration to the second interface configuration responsive to the temperature of the first component increasing across the predetermined threshold temperature.

41. The heat transfer arrangement according to any one of claims 38 to 40, wherein the moveable thermal interface is fixedly mechanically and configured to be thermally coupled to one of the first and second components, and is arranged to be selectively brought into and out of thermal coupling with the other of the first and second components.

42. The heat transfer arrangement according to claim 41, wherein the moveable thermal interface is flexible so as to permit extension towards and away from the other of the first and second components while remaining fixedly mechanically and thermally coupled to the one of the first and second components.

43. The heat transfer arrangement according to any one of claims 38 to 42, wherein the moveable thermal interface is configured to permit the first and second components to remain thermally coupled across the full range of variable spacing therebetween, and is configured to permit the first and second components to be thermally decoupled across the full range of the variable spacing.

44. The heat transfer arrangement according to any one of claims 38 to 43, wherein the thermally activated spacer arrangement comprises a shape memory alloy.

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