Heat exchange system

Abstract

A heat exchanger 100 for use with a heat pipe 110 comprising one or more passages containing a working fluid in both gas and liquid states. The heat exchanger comprises one or more inlet channels 102

Description

Field of the Invention The present invention relates to a heat transfer apparatus. 5 Background to the Invention A heat pipe is a hermetically sealed, evacuated tube or plate comprising a working fluid in both the liquid and vapour phase. When one part of the heat pipe is heated the liquid turns to vapour upon absorbing the latent heat of vaporization. The hot 10 vapour subsequently passes to the cooler part of the heat pipe where it condenses and releases the latent heat to the tube / plate. The condensed liquid then flows back to the hot part of the heat pipe and the vaporization-condensation cycle repeats. Since the latent heat of vaporization is usually very large, considerable quantities of heat can be transferred around the tube / plate and a substantially uniform temperature 15 distribution can be achieved along the heat pipe. An example heat pipe is described in WO 2015 / 193683 Al. In order to facilitate the vaporization-condensation cycle, a heat exchanger can be used to add or remove heat from the heat pipe, as needed. It is desirable to provide 20 an effective heat exchanger for a heat pipe. Summary Disclosed herein is a heat exchanger. The heat exchanger is for use with a heat pipe comprising one or more passages containing a working fluid in both gas and liquid 25 states. In a first aspect, the heat exchanger comprises one or more inlet channels configured to be in fluid communication with the one or more passages of the heat pipe and one or more central channels in fluid communication with the one or more inlet channels. 30 The one or more central channels are configured to form a (hermetically) sealed system with the heat pipe, such that the working fluid circulates between the one or more central channels and the one or more passages via the one or more inlet channels. The heat exchanger further comprises one or more peripheral channels disposed around the one or more central channels and fluidically separate from the 35 one or more central channels. A first heat exchange fluid is configured to pass through the one or more peripheral channels. Optionally, means for driving the first heat exchange fluid the one or more peripheral channels is also provided. In a second aspect, the heat exchanger comprises one or more inlet channels configured to be in fluid communication with the one or more passages of the heat pipe and one or more central channels in fluid communication with the one or more inlet channels. The one or more central channels are configured to form a sealed 5 system with the heat pipe, such that the working fluid circulates between the one or more central channels and the one or more passages via the one or more inlet channels. The heat exchanger further comprises one or more peripheral channels disposed around the one or more central channels and fluidically separate from the one or more central channels. A first heat exchange fluid is configured to pass 10 through the one or more peripheral channels. Optionally, an apparatus configured to drive the first heat exchange fluid through the one or more peripheral channels is also provided. In a third aspect, the heat exchanger comprises a manifold. Within the manifold are 15 formed one or more inlet channels configured to be in fluid communication with the one or more passages of the heat pipe and one or more central channels in fluid communication with the one or more inlet channels. The one or more central channels are configured to form a sealed system with the heat pipe, such that the working fluid circulates between the one or more central channels and the one or more passages via 20 the one or more inlet channels. Within the manifold are also formed one or more peripheral channels disposed around the one or more central channels and fluidically separate from the one or more central channels. A first heat exchange fluid is configured to pass through the one or more peripheral channels. Optionally, an apparatus configured to drive (or a means for driving) the first heat exchange fluid 25 through the one or more peripheral channels is also provided. By providing peripheral channels around the central channel(s) in accordance with aspects described herein, the efficiency of heat transfer to / from the heat pipe can be improved. An effective heat exchanger may therefore be provided, which can both 30 heat and cool the heat pipe, depending on the first heat exchange fluid used. The cooling can be passive, for example where the first heat exchange fluid is air which flows passively through the peripheral channels; this can be beneficial in low energy systems. The cooling can alternatively be active, where the first heat exchange fluid is a gas or liquid which is actively driven. This could include pumping or forcing the 35 fluid with a pump, compressor or other means, or e.g., actively blowing air through the channels. Optional features of the first and / or second and / or third aspects are set out below, and can be combined with one another in any suitable combination. In one example, the one or more inlet channels extend along a first direction, and the 5 one or more central channels extend along a second direction different to the first direction. Optionally, the first direction and the second direction are perpendicular. Optionally, the one or more peripheral channels also extend along the second direction. In this way, the central channels (and optionally peripheral channels) can be configured to run alongside an edge of the heat pipe, which can help maximise 10 heat transfer from the heat pipe whilst making efficient use of space. This can be important when retrofitting the heat exchanger, for example. In one example, the one or more central channels comprises a single channel. Optionally, when viewed in cross section, the single channel comprises: a substantially 15 circular edge; an edge that is at least partially scalloped; an irregular edge; or an edge that comprises one or more substantially triangular protrusions. An edge that is at least partially scalloped means a wavy edge, or an edge comprising a line of curves. By providing a central channel with one of these shapes, the surface area of the central channel can be increased, improving the heat transfer efficiency with the 20 peripheral channels. In other examples, the central channel can be any suitable shape or geometry. In one example, a cross section of each of the one or more peripheral channels is: substantially circular; substantially oblong; substantially triangular; or irregularly 25 shaped. By providing peripheral channel(s) with one of these shapes, the surface area of the peripheral channel(s) can be increased, improving the heat transfer efficiency with the central channel(s). In other examples, the peripheral channel(s) can be any suitable shape or geometry. 30 The central channel(s) and / or peripheral channel(s) can be any suitable shape in cross section. Optionally, the channels can be any shape that can be extruded or otherwise formed during a manufacturing process. In some arrangements, the cross sections of the central and peripheral channels can be complimentary, thereby improving the heat transfer between the channels. 35 In some examples, the heat exchanger further comprises at least one coil disposed in the one or more central channels, and optionally means for driving a second heat exchange fluid through the at least one coil. In some other examples, the heat exchanger further comprises at least one coil disposed in the one or more central channels, and optionally an apparatus configured to drive a second heat exchange fluid through the at least one coil. By providing a coil within the central channel, the heat exchange surface of the central channel can be increased, improving the heat 5 transfer efficiency of the heat exchanger. Moreover, two different heat exchange fluids can be used, further increasing the heat transfer to / from the heat pipe. The means / apparatus configured to drive the second exchange fluid can be the same means / apparatus as are configured to drive the first heat exchange fluid, or a different 10 means / apparatus. In some implementations the apparatus / means for driving the first heat exchange fluid comprises a pump or a compressor. In some implementations the apparatus / means for driving the second heat exchange fluid comprises a pump or a compressor. In other examples, the second heat exchange fluid is passively driven. 15 In some implementations, the first heat exchange fluid comprises: air; water; water glycol; thermal oil; a coolant; ora refrigerant. Any suitable heat exchange fluid in the coolant state can be used. In some implementations, the second heat exchange fluid comprises: air; water; water glycol; thermal coil; a coolant; or a refrigerant. Any suitable heat exchange fluid in the coolant state can be used. Different heat exchange 20 fluids may be selected for different applications of the heat exchanger. In some examples, the fluid can be selected depending on one or more of: whether the heat exchanger is to be active / passive, the amount of heat to be transferred by the heat exchanger, the operating temperature of the heat exchanger, etc. 25 Also disclosed herein is a system comprising a heat pipe comprising one or more passages containing a working fluid in both gas and liquid states and the heat exchanger of any aspect / example described herein. In some implementations, the heat exchanger is arranged such that the central channel is elevated with respect to the heat pipe. This allows gravity to assist in running the condensed liquid back to the 30 heat pipe. Optionally, the heat pipe is arranged in a substantially horizontal plane. For example, the heat pipe is a planar heat pipe arranged to lie flat in the (substantially) horizontal plane. This arrangement can be useful where the system is used as, for example, a cooling mat (i.e., the heat exchanger is configured to remove heat from the system, to cool one or more components). However, the heat pipe can 35 also be used to heat a component in this arrangement. In other arrangements, the heat exchanger can be arranged such that the heat pipe is elevated with respect to the central channel. This allows gravity to assist in running the condensed liquid back to the heat exchanger. Optionally, the heat pipe is arranged in a substantially vertical plane. For example, the heat pipe is a planar heat pipe arranged to sit in the (substantially) vertical plane. This arrangement can be useful where the system is used as, for example, a radiator (i.e., the heat exchanger 5 is configured to add heat to the system, which heat can be radiated from the heat pipe). However, the heat pipe can also be used to cool a component in this arrangement. Also disclosed herein is a vehicle comprising the system. Optionally, the vehicle 10 comprises one or more components, wherein the one or more components are thermally coupled to the heat pipe. Optionally, the one or more components comprise one or more batteries, wherein the one or more batteries are thermally coupled to the heat pipe. In this way, the heat pipe can be used to heat and / or cool the batteries, as needed. This can be beneficial during, for example, charging of the battery. This can 15 also be beneficial in maintaining the battery at a constant temperature, for example. Optionally, where the system is disposed in a vehicle, the apparatus / means for driving the first and / or second heat exchange fluid can comprise one or more existing components of the vehicle. For example, the compressor from the vehicle's air 20 conditioning system can be used to drive coolant from the air conditioning system through the one or more peripheral channels and / or the one or more coils. In another example, the pump from the vehicle's radiator can be used to drive a heat exchange fluid from the radiator through the one or more peripheral channels and / or the one or more coils. 25 As discussed above, these features can be combined in any suitable combination. Other applications of the heat exchanger described herein include, but are not limited to: the cooling and / or heating of one or more batteries and / or other electrical components; building cooling and / or heating in the form of radiators or air cooling 30 units; and condensation panels to cool air or harvest water. List of Figures The detailed description is with reference to the following figures: 35 Figure 1A is a schematic illustration of a cross section of an example of a heat exchanger as described herein, Figure IB is a schematic illustration of a cross section of another example of a heat exchanger as described herein, and Figure IC is a schematic illustration of a cross section of another example of a heat exchanger as described herein; Figure 2 is a schematic perspective view of a system comprising a heat exchangerand a heat pipe and a cross section of the system; 5 Figure 3A and Figure 3B show cross sectional illustrations of example orientations / arrangements of the system of Figure 2; Figure 4 is a cross sectional view of an example heat exchanger; Figure 5 is a cross sectional view of another example heat exchanger; Figure 6 is a cross sectional view of another example heat exchanger; io Figure 7A is a cross sectional view of another example heat exchanger, and Figure 7B is a cross sectional view of an alternative to the example of Figure 7A; and Figure 8 is a schematic illustration of example implementations of a heat exchanger as described herein, including a vehicle comprising said heat exchanger. 15 Detailed description Described herein is a heat exchanger. The heat exchanger is for use with a heat pipe comprising one or more passages, the passages containing a working fluid in both gas and liquid states. The heat exchanger can facilitate provision of a heat pipe with an isothermal surface, by exchanging heat to / from the heat pipe. 20 With reference to Figure 1A, a first example of a heat exchanger 100 is described. The heat exchanger comprises one or more inlet channels 102 configured to be in fluid communication with the one or more passages of the heat pipe (not shown). The heat exchanger also comprises one or more central channels 104 in fluid communication 25 with the one or more inlet channels 102. In this example cross section, there is a single inlet channel 102 and a single central channel 104 shown. The one or more central channels are configured to form a sealed system with the heat pipe, such that the working fluid within the heat pipe circulates between the one or more central channels 104 and the one or more passages of the heat pipe via the one or more inlet 30 channels 102. The heat exchanger further comprises one or more peripheral channels 106 disposed around the one or more central channels 104 and fluidically separate from the one or more central channels. Means for driving a first heat exchange fluid through the one 35 or more peripheral channels may also be provided (not shown). The peripheral channels 106 can be arranged in any suitable position around the central channel(s) 104. By providing peripheral channels around the central channel(s) in this way, the efficiency of heat transfer to / from the heat pipe can be improved. An effective heat exchanger may therefore be provided, which can both heat and cool the heat pipe, depending on the first heat exchange fluid used. In this example, the heat exchanger comprises a manifold 108 within which the inlet 5 channel(s) 102, central channel(s) 104 and peripheral channel(s) 106 are formed. As used herein, the term "manifold" can be understood to be any suitable component or block through which the channels can be formed, and which can facilitate connection of the channels to one or more external circuits or systems (including the heat pipe and optionally the means for driving the first and / or second fluid). The manifold can io simply be a block of suitable material, through which the channels are formed by extrusion or any other suitable manufacturing means. The manifold 108 can be configured to be coupled to the heat pipe in any suitable manner. The channels 104, 106 can be extruded within the manifold, or formed in 15 any suitable manner. The inlet channel 102 can also be formed in any suitable manner (and be any suitable size I shape) to facilitate fluidic coupling between the heat pipe and the central channel(s) 104. The ends of the manifold can be welded and / or a cap can be used in order to seal the central channel(s) 104 and provide a closed, hermetically sealed, system for operation of the heat pipe. In other examples, 20 the channels 102, 104, 106 can be formed in any suitable component to provide the desired coupling of the heat exchanger 100 to the heat pipe. In examples where the peripheral channels have passive fluid flow, one or more holes can be provided in the ends of the manifold to facilitate a flow of the first heat 25 exchange fluid (such as air) through the peripheral channels 106. Otherwise, the peripheral channels can be fluidly coupled through the ends of the manifold to the means / apparatus for driving the first heat exchange fluid. In this example, the central channel 104 and the peripheral channels 106 have 30 substantially circular edges when viewed in cross section (e.g., channels 104, 106 have substantially circular cross sections). However, the channels can have any suitable size and geometry, and it will be understood that the shapes shown in Figure 1A are for illustrative purposes only. Some specific geometries of the channels will be discussed below in more detail with reference to Figures 4 to 7B. 35 With reference to Figure IB, a second example of a heat exchanger 100 is described. The heat exchanger comprises one or more inlet channels 102 configured to be in fluid communication with the one or more passages of the heat pipe (not shown). The heat exchanger also comprises one or more central channels 104 in fluid communication with the one or more inlet channels 102. In this example cross section, there are two inlet channels 102 and two central channels 104 shown, each inlet channel connecting to a respective central channel. The one or more central channels are configured to 5 form a sealed system with the heat pipe, such that the working fluid within the heat pipe circulates between the one or more central channels 104 and the one or more passages of the heat pipe via the one or more inlet channels 102. In another example, the two channels 104 shown in Figure IB may be fluidly connected (for example at one or both ends) to form a single central channel 104, and only a single io inlet channel 102 may be provided. The heat exchanger further comprises one or more peripheral channels 106 disposed around the one or more central channels 104 and fluidically separate from the one or more central channels. Means for driving a first heat exchange fluid through the one 15 or more peripheral channels may also be provided (not shown). The peripheral channels 106 can be arranged in any suitable position around the central channel(s) 104. By providing peripheral channels around the central channel(s) in this way, the efficiency of heat transfer to / from the heat pipe can be improved. An effective heat exchanger may therefore be provided, which can both heat and cool the heat pipe, 20 depending on the first heat exchange fluid used. In this example, the heat exchanger comprises a manifold 108 within which the inlet channel(s) 102, central channel(s) 104 and peripheral channel(s) 106 are formed. The manifold can be configured to be coupled to the heat pipe in any suitable manner. 25 The channels 104, 106 can be extruded within the manifold, or formed in any suitable manner. The inlet channel(s) 102 can also be formed in any suitable manner to facilitate fluidic coupling between the heat pipe and the central channel(s) 104. The ends of the manifold can be welded and / or a cap can be used in order to seal the central channel(s) 104 and provide a closed, hermetically sealed, system for operation 30 of the heat pipe. In other examples, the channels 102, 104, 106 can be formed in any suitable component to provide the desired coupling to the heat pipe. In examples where the peripheral channels have passive fluid flow, one or more holes can be provided in the ends of the manifold to facilitate a flow of the first heat 35 exchange fluid (such as air) through the peripheral channels 106. In other examples, the air may be actively driven through said holes. In other examples where the fluid is actively driven, the peripheral channels can be fluidly coupled through the ends of the manifold to the means / apparatus for driving the first heat exchange fluid. In this specific example of Figure IB, the central channel 104 has a substantially semicircular cross section and the peripheral channels 106 each have substantially circular edges when viewed in cross section (e.g., substantially circular cross sections). 5 However, the channels can have any suitable size and geometry, and it will be understood that the shapes shown in Figure IB are for illustrative purposes only. Some specific geometries of the channels will be discussed below in more detail with reference to Figures 4 to 7B. io With reference to Figure IC, a third example of a heat exchanger 100 is described. As in Figure 1A, the heat exchanger 100 comprises one or more inlet channels 102 configured to be in fluid communication with the one or more passages of the heat pipe (not shown). The heat exchanger also comprises one or more central channels 104 in fluid communication with the one or more inlet channels 102. In this example 15 cross section, there is a single inlet channel 102 and a single central channel 104 shown, though other arrangements are possible. The description of Figure 1A is understood to apply to the features of Figure IC. In addition, as shown in Figure IC, the heat exchanger 100 additionally comprises at 20 least one coil 120 disposed in the one or more central channels 104, and optionally an apparatus / means for driving a second heat exchange fluid through the at least one coil (not shown). In other arrangements, the second heat exchange fluid may passively flow through the coil. By providing a coil within the central channel, the heat exchange surface of the central channel 104 can be increased, improving the 25 heat transfer efficiency of the heat exchanger. In examples where the coil has passive fluid flow, one or more holes can be provided in the ends of the manifold to facilitate a flow of the second heat exchange fluid (such as air) through the coil. In other examples, the air may be actively driven through said holes. In other examples where the fluid is actively driven, the coil can be fluidly coupled through the ends of the 30 manifold to the means / apparatus for driving the second heat exchange fluid. As in Figure 1A, the heat exchanger of Figure IC further comprises one or more peripheral channels 106 disposed around the one or more central channels 104 and fluidically separate from the one or more central channels. Means for driving a first 35 heat exchange fluid through the one or more peripheral channels may also be provided (not shown). The peripheral channels 106 can be arranged in any suitable position around the central channel(s) 104. By providing peripheral channels around the central channel(s) in this way, the efficiency of heat transfer to / from the heat pipe can be improved. An effective heat exchanger may therefore be provided, which can both heat and cool the heat pipe, depending on the first heat exchange fluid used. Moreover, by adding the coil 120, in some examples two different heat exchange fluids can be used, further increasing the heat transfer to / from the heat pipe. 5 With reference to Figure 2, a system 200 is described. The system comprises a heat pipe 110 comprising one or more passages containing a working fluid in both gas and liquid states and the heat exchanger 100. Only a portion of heat pipe 110 is shown in Figure 2, and the internal passages are not shown. The cross-sectional surface io (shown in grey) shows examples of the inlet channel 102, central channel 104 and peripheral channels 106 disposed around the central channel (as per Figures 1A, IB, IC). These channels 102 104, 106 are formed within the manifold 108 in this example. Although not shown, the inlet channel is configured to be in fluid communication with the passages of the heat pipe 110. 15 The apparatus / means for driving the first and / or second heat exchange fluid through the peripheral channels (not shown) can be arranged external to the manifold 108 / heat exchanger and heat pipe 110. By driving heat exchange fluid through the peripheral channels, heat can be transferred to / from the central channels, and thereby 20 to / from the heat pipe 110. This could include pumping or forcing the fluid with a pump, compressor or other means, or e.g., actively blowing air through the channels. In other examples, the flow of heat exchange fluid can be passive (e.g., passive air flow or the like), which can be of benefit in low energy systems. 25 In the example of Figure 2, the one or more inlet channels 102 extend along a first direction 212, and the one or more central channels 104 extend along a second direction 214 different to the first direction. The first direction and the second direction are perpendicular (or generally perpendicular) in this specific example, and the one or more peripheral channels also extend along the second direction 214. In 30 this way, the central channels (and here the peripheral channels) can be configured to run alongside an edge of the heat pipe, as shown, which can help maximise heat transfer from the heat pipe whilst making efficient use of space by providing a more compact heat exchanger 100. This can be important when retrofitting the heat exchanger, for example. However, the channels can run in any other orientation, as 35 needed. The heat exchanger and heat pipe of Figure 2 can be arranged in any suitable orientation, and can be connected to one another in any suitable orientation / configuration. For example, with reference to Figure 3A, the heat exchanger 100 is arranged such that the central channel 104 is elevated with respect to the heat pipe 110. This allows gravity to assist in running the condensed liquid back to the heat pipe. Optionally, the heat pipe is arranged in a substantially 5 horizontal plane. For example, the heat pipe is a planar heat pipe arranged to lie flat in the (substantially) horizontal plane. This arrangement can be useful where the system is used as, for example, a cooling mat (i.e., the heat exchanger is configured to remove heat from the system, to cool one or more components). However, the heat pipe can also be used to heat a component in this arrangement. io In another example, with reference to Figure 3B, the heat exchanger can be arranged such that the heat pipe is elevated with respect to the central channel. This allows gravity to assist in running the condensed liquid back to the heat exchanger. Optionally, the heat pipe is arranged in a substantially vertical plane. For example, 15 the heat pipe is a planar heat pipe arranged to sit in the (substantially) vertical plane. This arrangement can be useful where the system is used as, for example, a radiator (i.e., the heat exchanger is configured to add heat to the system, which heat can be radiated from the heat pipe). However, the heat pipe can also be used to cool a component in this arrangement. 20 With reference to Figures 4 to 7B, specific example geometries of the central channels 104 and peripheral channels 106 will now be described in more detail. It will be understood that these are examples only, and that any channel geometry, and any combination of channel geometries, can be used. 25 With reference to Figure 4, an example heat exchanger comprises a single central channel 104, which is configured to be connected to the heat pipe (not shown) by the inlet channel 102. When viewed in cross section, the single channel comprises a substantially circular edge. A plurality of peripheral channels 106 are disposed around 30 the single central channel. A cross section of each of the one or more peripheral channels is (substantially) oblong, though in some examples the oblongs may be slightly curved around the single channel to maintain a constant or near constant distance between the central channel 104 and each peripheral channel 106. No coil is disposed within the channel in this example, though coil 120 may be used. Heat 35 transfer occurs between the heat pipe and the peripheral channels 106 via the central channel 104 (which is part of a closed, hermetically sealed system with the heat pipe that is fluidly separated from the peripheral channels). With reference to Figure 5, an example heat exchanger comprises a single central channel 104, which is configured to be connected to the heat pipe (not shown) by the inlet channel 102. When viewed in cross section, the single channel comprises an edge. The edge comprises one or more substantially triangular protrusions 530. In 5 this specific example, there are a plurality of substantially triangular protrusions 530 around the edge of the central channel 104. A plurality of peripheral channels 106 are disposed around the single central channel. A cross section of each of the one or more peripheral channels is (substantially) triangular. The peripheral channels can be disposed between the protrusions 530 of the central channel. In this way, the edges of io the central channel 104 and the peripheral channels can substantially correspond, increasing the surface area over which heat can be transferred between the respective fluids in the respective channels (i.e., between the working fluid in the central channel 104 and the first heat exchange fluid in the peripheral channels 106). No coil is disposed within the channel in this example, though coil 120 may be used. By 15 providing central and peripheral channels with these corresponding triangular protrusions / shapes, the heat transfer efficiency can be improved. A portion of another example heat exchanger is shown in Figure 6. Similar to Figure 5, the heat exchanger 100 comprises a single central channel 104, which is configured 20 to be connected to the heat pipe by the inlet channel (not shown). When viewed in cross section, the single channel comprises an edge that comprises one or more substantially triangular protrusions 530. In this specific example, there are a plurality of substantially triangular protrusions 530 around the edge of the central channel 104. A plurality of peripheral channels 106 are disposed around the single central channel. 25 k cross section of each of the one or more peripheral channels is irregularly shaped. In this way, the edges of the central channel 104 and the peripheral channels can substantially correspond, but there is more material between the separate channels. This arrangement can help to balance heat transfer efficiency with strength of the heat exchanger design. For example, the portion of the heat exchanger 100 surrounding 30 the peripheral channels may be reinforced as compared to the arrangement of Figure 5 so as to provide a desired structural strength to the heat exchanger. No coil is disposed within the channel in this example, though coil 120 may be used. In accordance with Figure 7A, another example heat exchanger is described. The heat 35 exchanger comprises a single central channel 104, which is configured to be connected to the heat pipe (not shown) by the inlet channel 102. When viewed in cross section, the single channel comprises an edge that is at least partially scalloped, i.e., which includes a plurality of curved protrusions 740 around the edge. A plurality of peripheral channels 106 are disposed around the single central channel. A cross section of each of the one or more peripheral channels is (substantially) circular. The peripheral channels can be disposed between the protrusions 740 of the central channel. In this way, the edges of the central channel 104 and the peripheral 5 channels can substantially correspond, increasing the surface area over which heat can be transferred between the respective fluids in the respective channels (i.e., between the working fluid in the central channel 104 and the first heat exchange fluid in the peripheral channels 106). No coil is disposed within the channel in this example, though coil 120 may be used. By providing central and peripheral channels io with these circular protrusions / shapes, the heat transfer efficiency can be improved. Figure 7B describes a similar arrangement to Figure 7A, but a coil 120 is disposed within the central channel 104. Apparatus / means for driving a second heat exchange fluid through the coil 120 are also provided (not shown here). By providing the coil in 15 addition to the peripheral channels, heat transfer to / from the channels can be increased. Efficiency of the heat exchanger 100 may therefore be improved. The central channel 104 is shown in the Figures described above as generally being in, or proximal, to the centre of the manifold 108 or the heat exchanger 100. However, 20 the Figures are for illustrative purposes only and the location of the central channel is not limited to the positions shown herein. The central channel 104 can be located at any position within the manifold 108 or heat exchanger 100. The term "central" channel does not imply the channel 104 is in the centre of the heat exchanger, but is used herein to distinguish the central channel 104 from the "peripheral" channels 106 25 which are disposed around it. Any suitable size, shape and location of the central and peripheral channels can be used, as the skilled person would understand, in order to provide the heat exchange benefits described herein. Moreover, the geometries of the central and peripheral 30 channels can be combined in any suitable arrangements. For example, a scalloped central channel can be combined with a triangular peripheral channel. In another example, a central channel with triangular protrusions can be combined with an oblong peripheral channel / s. The specific combinations of geometries can depend on the application of the heat exchangerand the desired structural strength and heat 35 transfer properties. As discussed herein, any suitable apparatus / means can be used to drive the first and / second heat exchange fluid through the peripheral channels and / or coil. For example, a pump or compressor can be used, or any other device configured to cause circulation of said heat exchange fluid through the channels / coil. In other examples, the flow of the first and / or second heat exchange fluid can be passive (e.g., there is not driving means to actively drive the fluid). In some examples, the first and / or 5 second heat exchange fluid comprises air, water, water glycol, thermal oil, a coolant, or a refrigerant. Any suitable fluid can be used, depending on the desired application of the heat exchanger. With reference to Figure 8, a schematic illustration of the heat exchanger 100 is io provided. The heat exchanger 100 comprises: one or more inlet channels extending configured to be in fluid communication with the one or more passages of the heat pipe 110; one or more central channels in fluid communication with the one or more inlet channels and configured to form a hermetically sealed system with the heat pipe (so as to communication a working fluid around the sealed system between the 15 passages of the heat pipe and the central channel); and one or more peripheral channels disposed around the one or more central channels and fluidically separate from the one or more central channels. The heat exchanger also optionally comprises an apparatus or means 852 for driving a first heat exchange fluid through the one or more peripheral channels. In some examples, the means 852 for driving the first heat 20 exchange fluid comprises a pump or a compressor. Optionally, at least one coil is disposed in the one or more central channels and the heat exchanger 100 optionally further comprises an apparatus or means 854 for driving a second heat exchange fluid through the at least one coil. In some examples, 25 the means 854 comprises a pump or a compressor. The system 200 comprises the heat pipe 110 having one or more passages containing a working fluid (in both gas and liquid states) and the heat exchanger 100, as discussed above with respect to Figure 2. 30 Optionally, a vehicle 800 comprises the system 200. In some examples, the vehicle comprises one or more components 856 that are thermally coupled to the heat pipe 110 (indicated by the arrow in Figure 8). Optionally, the components 856 comprise one or more batteries, wherein the one or more batteries are thermally coupled to the 35 heat pipe. Where the system 200 is disposed in a vehicle 800, the apparatus / means for driving the first 852 and / or second 854 heat exchange fluid can comprise one or more existing components of the vehicle 800. For example, the compressor from the vehicle's air conditioning system can be used to drive coolant from the air conditioning system through the one or more peripheral channels and / or the one or more coils. In another example, the pump from the vehicle's radiator can be used to drive a heat 5 exchange fluid from the radiator through the one or more peripheral channels and / or the one or more coils. However, any suitable configuration can be used, depending on the desired application of the heat exchanger.

Claims

1. A heat exchanger (100) for use with a heat pipe (110), the heat pipe comprising one or more passages containing a working fluid in both gas and liquid5 states, the heat exchanger comprising:one or more inlet channels (102) configured to be in fluid communication with the one or more passages of the heat pipe;one or more central channels (104) in fluid communication with the one or more inlet channels and configured to form a sealed system with the heat pipe;io one or more peripheral channels (106) disposed around the one or morecentral channels and fluidically separate from the one or more central channels; and wherein a first heat exchange fluid is configured to pass through the one or more peripheral channels.15 2. The heat exchanger of claim 1, wherein the one or more central channelscomprises a single channel.

3. The heat exchanger of claim 2, wherein, in cross section, the single channel comprises:20 a substantially circular edge;an edge that is at least partially scalloped; oran edge that comprises one or more substantially triangular protrusions.

4. The heat exchanger of any preceding claim, wherein a cross section of each of 25 the one or more peripheral channels is:substantially circular;substantially oblong; or irregularly shaped.30 5. The heat exchanger of any preceding claim, further comprising:at least one coil (120) disposed in the one or more central channels; and means for driving (854) a second heat exchange fluid through the at least one coil.35 6. The heat exchanger of claim 5, wherein the second heat exchange fluidcomprises:air;water;a coolant; or a refrigerant.

7. The heat exchanger of claim 5 or claim 6, wherein the means for driving the5 second heat exchange fluid comprises a pump or a compressor.

8. The heat exchanger of any preceding claim, wherein the first heat exchange fluid comprises:air;io water;a coolant; or a refrigerant.

9. The heat exchanger of any preceding claim, further comprising means for 15 driving (852) the first heat exchange fluid through the one or more peripheral channels, optionally, wherein the means for driving the first heat exchange fluid comprises a pump or a compressor.

10. The heat exchanger of any preceding claim, wherein the one or more inlet 20 channels extend along a first direction (212), and the one or more central channels extend along a second direction (214) different to the first direction.

11. The heat exchanger of claim 10, wherein the one or more peripheral channels extend along the second direction.2512. The heat exchanger of claim 10 or claim 11, wherein the first and second directions are perpendicular to one another.

13. A system (200) comprising:30 a heat pipe (110) comprising one or more passages containing a working fluidin both gas and liquid states; andthe heat exchanger (100) of any preceding claim.

14. The system of claim 13, wherein the heat exchanger is arranged such that the 35 central channel is elevated with respect to the heat pipe.

15. The system of claim 13 or claim 14, wherein the heat pipe is arranged in a substantially horizontal plane.

16. A vehicle comprising the system of any of claims 13 to 15.

17. The vehicle of claim 16, the vehicle comprising one or more batteries, wherein5 the one or more batteries are thermally coupled to the heat pipe.19

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