Patent ID: 12222165

DETAILED DESCRIPTION

With reference toFIGS.1to9, a first embodiment of the apparatus102for transferring heat from a heat source104to air when the apparatus102is connected to the heat source104according to the first aspect is schematically shown. With reference toFIGS.1and2, in the shown embodiment, each heat source104is an electric or electronic component attached or mounted to a printed circuit board (PCB)105. The electric or electronic component may be a transmitter, an optical transducer, a power amplifier or any other heat-generating component, or any other heat-generating electric or electronic component. However, it is to be understood that the heat source104in alternative embodiments may be a component not mounted to a PCB105. In the embodiments shown, there are four heat sources104. For example, the heat source104or heat sources104, and for example also the PCB105, may be part of a network access node for a wireless communication system. The network access node may comprise a base station.

The apparatus102includes a heat sink106. The heat sink106includes a heat sink base108and a plurality of primary fins110connected to the heat sink base108. Each primary fin110of the plurality of primary fins110may be connected to the heat sink base108by being attached to the heat sink base108or by being formed integrally with the heat sink base108. The primary fins110are provided in a plurality of primary fin modules111, or sections. Each primary fin module111includes a plurality of primary fins110. When the apparatus102and heat sink106are installed, i.e., have been installed and are in an installed state, the plurality of primary fins110of the same module111are arranged side by side but with a space of air between two adjacent primary fins110. In the embodiment shown, four primary fin modules111are provided. However, fewer fin modules111may be provided, for example even only one fin module111, or more modules111may be provided. As shown inFIGS.1and2, when the apparatus102and heat sink106are installed, the primary fin modules111are arranged or located one above the other.

With reference toFIGS.1and2, in lateral directions, each primary fin110forms an angle of approximately 90 degrees with the heat sink base108. However, in vertical directions113, each primary fin110forms a non-perpendicular angle with the heat sink base108. However, in alternative embodiments, in lateral directions each primary fin110may form a non-perpendicular angle with the heat sink base108. Further, the heat sink102includes a heat sink front112. In the shown embodiments, the heat sink front112is formed as a part or structure separate from the primary fins110. However, the heat sink front is not necessarily a part or structure separate from the primary fins110, but may simply be the region where the primary fins110end toward the front and may thus be formed by parts of the primary fins110. Each primary fin110of the plurality of primary fins110may be connected to the heat sink front112. Each primary fin110of the plurality of primary fins110may be connected to the heat sink front112by being attached to the heat sink front112or by being formed integrally with the heat sink front112.

The heat sink base108is configured to be thermally coupled to the heat source104or sources104. With reference toFIG.4, each primary fin110of the plurality of primary fins110includes, or defines, one or more conduits114, such as longitudinal hollows. In the embodiment shown, in lateral directions, each conduit114forms an angle of approximately 90 degrees with the heat sink base108. However, in vertical directions113, each conduit114forms a non-perpendicular angle with the heat sink base108. Each primary fin110and associated conduits114may be formed by extrusion or by adjoining two plates. However, other ways of producing the primary fins110are possible. When the apparatus102and heat sink106are installed, the conduits114of the same primary fin110may be arranged or located one above the other.

With reference toFIG.5, the heat sink base108includes, or defines, a first chamber116. The first chamber116and the conduits114together form, or define or constitute, a joint or common space sealed off from the ambient air surrounding the apparatus102and the heat sink106. Thus, the first chamber116and the conduits114are parts of the common space. In other words, the plurality of primary fins110and the heat sink base112form or define the common space. The common space may be called an internal or physical space, for example a room, which forms an internal volume or common internal volume.

Further, the first chamber116and the conduits114together enclose, or contain or hold, a heat-carrying fluid in the common space formed by the first chamber116and the conduits114. It is to be understood that the fluid can be a liquid or a vapour (gas) or a mixture thereof. As mentioned above, each conduit114is a hollow, for example integrated in the respective primary fin110, for example an elongated hollow. Each conduit114can hold the fluid and may transport or convey the fluid along its length or longitudinal extension. By means of the fluid, heat is transferred away from the first chamber116via the conduits114. The heat sink106may be called a liquid- and vapour-based heat sink106.

The heat sink base108and/or the first chamber116may include one or more wick structures configured to be adjacent to a heat source104. A wick structure per se is known to the skilled person and thus not further discussed in more detail. Each conduit114opens into the first chamber116. The conduits114are fluidly connected to the first chamber116. “Fluidly connected” in the context of the present disclosure and with regard to two entities, for example the conduit114and the first chamber116, means that the two entities are in fluid communication with one another, i.e., that a fluid can travel from one of the entities to the other entity, for example, a fluid can travel between the conduit114and the first chamber116.

With reference toFIGS.3and5, the heat sink base108includes a heat sink base plate117in contact with and/or adjacent to the heat sources104and/or the PCB105. The heat sink base108also includes a heat sink base cover118. The heat sink base cover118is provided with a plurality of openings or slots via which the conduits114of the primary fins110are fluidly connected to the first chamber116. The heat sink base plate117is located between the heat sources104and the heat sink base cover118. The heat sink base plate117is also located between the PCB105and the heat sink base cover118.

The first chamber116and the conduits114form the common space such that heat is carried by the fluid from the first chamber116to the conduits114. The first chamber116and the conduits114form the common space such that heat is carried by the fluid from the first chamber116to the heat sink front112via the conduits114. This is illustrated by the arrows pointing upward and to the right inFIG.7. The heat sink base108defines a hot interface, wherein the apparatus102at the hot interface is configured to turn a liquid of the fluid inside the common space into a vapour by allowing the liquid to absorb heat from the hot interface. In other words, the heat sink base108has a surface for turning a liquid of the fluid inside the common space, more specifically, inside the first chamber116, into a vapour by allowing the liquid to absorb heat from said surface of the heat sink base108or from the heat sink base108. The first chamber116has a shell117,118, for example formed by the heat sink base plate117and the heat sink base cover118. The apparatus102at the hot interface, or at said surface, is configured to turn a liquid of the fluid inside the common space, more specifically, inside the first chamber116, into a vapour by allowing the liquid to absorb heat from the shell117,118of the first chamber116. The first chamber116and the conduits114form the common space such that a vapour of the fluid travels from the first chamber116of the heat sink base108, along the conduits114and toward the heat sink front112. This is illustrated by the arrows pointing upward and to the right inFIG.7.

Each primary fin110of the plurality of primary fins110may have a surface for condensing a vapour of the fluid inside the common space into a liquid. The first chamber116and the conduits114form the common space such that a liquid of the fluid is returned back to the first chamber116by way of any one of capillary action, gravity and pressure differences of the fluid. This is illustrated by the arrows pointing downward and to the left inFIG.7. Thus, each conduit114can be described as a fluid-guiding hollow. Some conduits114are configured to guide fluid, for example vapour, from the heat sink base108to the heat sink front112, whereas other conduits114are configured to guide fluid, for example condensed liquid, from the heat sink front112to the heat sink base108. However, some conduits114may be configured to guide the fluid both from the heat sink base108to the heat sink front112and from the heat sink front112to the heat sink base108.

With reference toFIGS.3and6, the heat sink front112may comprise a heat sink front cover119and a heat sink front plate121. In the shown embodiment, the heat sink cover119is located between the heat sink front plate121and the primary fins110. The heat sink front112includes, or defines, a second chamber120. The first chamber116, the conduits114and the second chamber120together form a common space sealed off from the ambient air surrounding the apparatus102, wherein the first chamber116, the conduits114and the second chamber120together enclose a heat-carrying fluid in the common space formed by the first chamber116, the conduits114and the second chamber120. The conduits114are fluidly connected to the second chamber120. Each conduit114may extend from the first chamber116to the second chamber120. The second chamber120may have a shell119,121, for example formed by the heat sink front cover119and the heat sink front plate121of the heat sink front112. The heat sink front cover119is provided with a plurality of openings or slots via which the conduits114of the primary fins110are fluidly connected to the second chamber120. The second chamber120is fluidly connected to the first chamber116via the conduits114. The heat sink front112may be called a condenser.

By the fluid, heat is transferred away from the first chamber116via the conduits114to the second chamber112, for example by evaporating a liquid of the fluid into a vapour in the first chamber116. The vapour may then travel through the conduits114. When the fluid has released heat, for example by condensing a vapour of the fluid into a liquid, for example in the conduit114of the primary fin110and/or in the second chamber120, the fluid in the form of a liquid is conveyed back to the first chamber116via the conduits114. The first chamber116, the conduits114and the second chamber120may form the common space such that an evaporated vapour of the fluid travels from the first chamber116to the second chamber120via the conduits114. The heat sink front112has a surface for condensing a vapour of the fluid inside the common space, more particularly inside the second chamber120, into a liquid. The first chamber116, the conduits114and the second chamber120may form the common space such that a condensed liquid of the fluid travels from the second chamber120to the first chamber116via the conduits114. The condensing of a vapour into a liquid, the movement of the liquid in the second chamber120and the movement of the liquid from the second chamber120to the first chamber116via the conduits114are illustrated by the arrows pointing downward and to the left inFIG.7.

InFIGS.8and9, the movement of the fluid, in the form of vapour or liquid, at the heat sink base side and at the heat sink front side, respectively, is illustrated. With reference toFIGS.1to9, when the apparatus102and heat sink106are installed, the heat sink base108and he heat sink front112may extend substantially in a vertical direction113. When the apparatus102and heat sink106are installed, one or more of the first and second chambers116,120may extend substantially in a vertical direction113.

With reference toFIG.10, in a second embodiment of the apparatus202according to the first aspect, the heat sink front212of the heat sink206comprises, or defines, both a second chamber220and a fourth chamber226. The heat sink base208comprises, or defines, both the first chamber216and a third chamber222. The first chamber216, the conduits114of each primary fin110of a first group of the plurality of primary fins110and the second chamber220together form a common space sealed off from the ambient air surrounding the apparatus202. The first chamber216, the conduits114of each primary fin110of the first group of the plurality of primary fins110and the second chamber220together enclose a heat-carrying fluid in the common space formed by the first chamber216, the conduits114of each primary fin110of the first group of the plurality of primary fins110and the second chamber220.

With reference toFIG.10, the third chamber222, the conduits114of each primary fin110of a second group of the plurality of primary fins110and the fourth chamber226together form a common space sealed off from the ambient air surrounding the apparatus202. The third chamber222, the conduits114of each primary fin110of the second group of the plurality of primary fins110and the fourth chamber226together enclose a heat-carrying fluid in the common space formed by the third chamber222, the conduits114of each primary fin110of the second group of the plurality of primary fins110and the fourth chamber226.

With reference toFIG.10, at the heat sink base208, the conduits114of each primary fin110of the first group of the plurality of primary fins110are fluidly connected to the first chamber216but sealed off (fluidly disconnected/separated) from the third chamber222, wherein at the heat sink base208the conduits114of each primary fin110of the second group of the plurality of primary fins110are fluidly connected to the third chamber222but sealed off (fluidly disconnected/separated) from the first chamber116. At the heat sink front212the conduits114of each primary fin110of the first group of the plurality of primary fins110are fluidly connected to the second chamber220but sealed off (fluidly disconnected/separated) from the fourth chamber226, wherein at the heat sink front212the conduits114of each primary fin110of the second group of the plurality of primary fins110are fluidly connected to the fourth chamber226but sealed off (fluidly disconnected/separated) from the second chamber220.

With reference toFIG.10, at the heat sink base208, the first and third chambers216,222may be sealed off (fluidly disconnected) from one another by means of one or more first blocks228. At the heat sink front212, the third chamber222and the fourth chamber226may be sealed off (fluidly disconnected) from one another by means of one or more second blocks230. The movement of the fluid with regard to the second embodiment is illustrated with arrows inFIG.10. With reference toFIG.10, the primary fins110shown can be described as belonging to two different modules or sections. In this manner, at the heat sink base208, the conduits114are provided with and open into different evaporation chambers216,222formed by the heat sink base208and the first and third chambers216,222, and at the heat sink front212the conduits114are provided with and open into different condensers, or condenser chambers, formed by the heat sink front212and the second and fourth chambers220,226. InFIGS.11and12, the movement of the fluid, in the form of vapour or liquid, at the heat sink base side and at the heat sink front side, respectively, of the second embodiment of the apparatus202is illustrated. With reference toFIG.10, when the apparatus202and heat sink206are installed, one or more of the first, second, third and fourth chambers216,220,222,226may extend substantially in a vertical direction113.

In an alternative embodiment, which is modified in relation to the first embodiment of the apparatus102shown inFIGS.1to9and in relation to the second embodiment of the apparatus202shown inFIGS.10to12, the heat sink base208includes a third chamber222, wherein the first chamber216, the conduits114and the third chamber222together form a common space sealed off from the ambient air surrounding the apparatus. The first chamber216, the conduits114and the third chamber222together enclose a heat-carrying fluid in the common space formed by the first chamber216, the conduits114and the third chamber222. At the heat sink base208the conduits114of each primary fin110of a first group of the plurality of primary fins110are fluidly connected to the first chamber216but sealed off from the third chamber222, and wherein at the heat sink base208the conduits114of each primary fin110of a second group of the plurality of primary fins110are fluidly connected to the third chamber222but sealed off from the first chamber216. Thus, at the heat sink base208the first and third chambers216,222are sealed off from one another, and at the heat sink base208the conduits114open into different evaporation chambers216,222, which corresponds to the heat sink base208of the second embodiment of the apparatus202shown inFIGS.10to12. However, at the heat sink front112the conduits114open into the same second chamber120, which corresponds to the heat sink front112of the first embodiment of the apparatus102shown inFIGS.1to9. Thus, at the heat sink front112, the conduits114share a common condenser, or condenser chamber, formed by the heat sink front112and the second chamber120.

InFIG.13, a part of a third embodiment of the apparatus302according to the first aspect of the disclosure is schematically illustrated. The apparatus302has four primary fin modules211. Each primary fin module211includes a plurality of primary fins210. In lateral directions, each primary fin210forms an angle of approximately 90 degrees with the heat sink base108of the heat sink306, and also in vertical directions113, each primary fin210forms an angle of approximately 90 degrees with the heat sink base108. Thus, in the third embodiment of the apparatus302, in lateral directions each conduit214(seeFIGS.16and21) may form an angle of approximately 90 degrees with the heat sink base108, and also in vertical directions113, each conduit214may form an angle of approximately 90 degrees with the heat sink base108.

With reference toFIGS.14to17, a fourth embodiment of the apparatus402according to the first aspect is schematically illustrated. Only one section or module211of primary fins210is shown, but it is to be understood that the same features can apply to additional modules of primary fins210. At the heat sink base108, all primary fins210of the module may open into the same first chamber116. However, at the heat sink front412the conduits214(seeFIG.16) of a first primary fin210of the plurality of primary fins210are sealed off from the conduits214of a second primary fin210of the plurality of primary fins210. Thus, with reference toFIGS.15and16, at the heat sink front412the conduits214of each primary fin210are provided with and open into their own individual condenser chamber420sealed off from the individual condenser chambers420of the conduits214of the other primary fins210of the module211. The individual condenser chambers420extend substantially in a vertical direction113when the heat sink406and apparatus402are installed. At the heat sink front412, between the individual condenser chambers420, louvres432, or tongues or flaps, may be provided to assist in the heat transfer from the heat sink front412to air. InFIG.17, the movement of the fluid, in the form of vapour or liquid, at the heat sink base side and at the heat sink front side, respectively, of the fourth embodiment of the apparatus is illustrated.

With reference toFIG.16, the apparatus402may comprise a plurality of secondary fins434. Each secondary fin434of the plurality of secondary fins434is connected to a primary fin210of the plurality of primary fins210. A plurality of secondary fins434may be connected to the same primary fin210. InFIG.16, only three secondary fins434connected to one primary fin210are shown. However, it is to be understood that more secondary fins434can be provided, which may be connected to one or more primary fins210of the plurality of primary fins210. For example, secondary fins434may be located between two primary fins210. Each secondary fin434of the plurality of secondary fins434may be connected to a primary fin210by being attached to, for example by welding, the primary fin210or by being formed integrally with the primary fin210. However, it is to be understood that the secondary fins434may be excluded in alternative embodiments.

With reference toFIGS.18to21, a fifth embodiment of the apparatus502according to the first aspect of the disclosure is schematically illustrated. Only one section or module211of primary fins210is shown, but it is to be understood that the same features can apply to additional modules211of primary fins210. At the heat sink base108, all primary fins210of the module may open into the same first chamber116. However, with reference toFIGS.20and21, at the heat sink front512the conduits214of a first primary fin210of the plurality of primary fins210are sealed off from the conduits214of a second primary fin210of the plurality of primary fins210. Thus, with reference toFIGS.20to21, at the heat sink front512the conduits214of each primary fin210are provided with and open into their own individual condenser chamber520sealed off from the individual condenser chambers520of the conduits214of the other primary fins210of the module211. Each individual condenser chamber520may be formed by a U-shaped member534. The U-shaped members534may be connected to a common frame536. However, in an alternative embodiment, the common frame536may be excluded. When the heat sink506and apparatus502are installed, the individual condenser chambers520extend substantially in a vertical direction113. At the heat sink front512, between the individual condenser chambers520, air is present. The movement of the fluid, in the form of vapour or liquid, at the heat sink base side and at the heat sink front side, respectively, of the fifth embodiment of the apparatus502corresponds to the movement illustrated inFIG.17.

With reference to the embodiments disclosed above, each primary fin110,210of the plurality of primary fins110,210may extend from the heat sink base108,208to the heat sink front112,212,412,512. The heat sink front112,212,412,512may advantageously be located opposite the heat sink base108,208. With reference to the embodiments disclosed above, each primary fin110,210of the plurality of primary fins110,210may be connected to the heat sink front112,212,412,512. Each primary fin110,210of the plurality of primary fins110,210may be connected to the heat sink front112,212,412,512by being attached to the heat sink front112,212,412,512, for example by being welded or attached by other mechanical means of attachment, or by being formed integrally with the heat sink front112,412,512.

The parts or units of the heat sink106may be made of any suitable material, for example a heat-conducting material, such as any suitable metal or metal alloy, for example aluminium, copper etc. The amount or volume of the fluid in relation to the volume of the common space may be dependent on the locations of the heat sources to be cooled by the heat sink106,206,306,406,506, for example such that a surface of a liquid of the fluid in the first chamber116is above the heat source104which is located vertically highest in relation to the other heat sources104when the heat sink106,206,306,406,506and apparatus102,202,302,402,502are installed, i.e., have been installed. The fluid may be water or a fluid known under the name R135A or R1233ZD, or any other suitable fluid. The first chamber116may include additional conduits, channels and/or partitions extending in various directions. The primary fins110do not have to be parallel to one another. When the apparatus102,202,302,402,502and heat sink106,206,306,406,506are installed, the heat sink base108,208and the heat sink front112,212,412,512may extend substantially in a vertical direction113. When the apparatus102,202,302,402,502and heat sink106,206,306,406,506are installed, the conduit114,214may extend substantially in a horizontal direction, or may form an angle with the horizontal plane. The heat sink106,206,306,406,506of the embodiments disclosed above may also be used in combination with one or more fans. The meaning of a “plurality” in the present disclosure or in the claims should be understood as two or more.

The embodiments of the present disclosure also comprise a network access node for a wireless communication system, wherein the network access node comprises an apparatus102,202,302,402,502according to any one of the embodiments disclosed above. The network access node herein may also be denoted as a radio network access node, an access network access node, an access point, or a base station, e.g., a Radio Base Station (RBS), which in some networks may be referred to as transmitter, “gNB”, “gNodeB”, “eNB”, “eNodeB”, “NodeB” or “B node”, depending on the technology and terminology used. The radio network access nodes may be of different classes such as, e.g., macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby also cell size. The radio network access node can be a Station (STA), which is any device that contains an IEEE 802.11-conformant Media Access Control (MAC) and Physical Layer (PHY) interface to the Wireless Medium (WM). The radio network access node may also be a base station corresponding to the fifth generation (5G) wireless systems. The network access node may include an active antenna, a remote radio unit (RRU) or a base band processor. The network access node may include one or more antennas. The network access node may have a housing, which houses the antenna. Alternatively, the antenna may be mounted outside the housing of the network access node, for example, with a distance to the housing of the network access node.

Finally, it should be understood that the disclosure is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claim.