JP2018044747A - Boiling/cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology which can expedite the separation of air bubbles from heat radiation fins and an internal face of a bottom wall part.SOLUTION: A boiling/cooling device 2 comprises: an inlet 12 into which a refrigerant flows; an outlet 14 from which the refrigerant flows; and a boiler 16 in which the refrigerant flows toward the outlet 14 from the inlet 12. The boiler 16 has: a radiator plate 40 which is arranged at an internal face of a bottom face part 24, and thermally connected to a heat generation body 60 at its external face; a tapered table 42 fixed to the internal face of the radiator plate 40; a plurality of heat radiation fins 50 protruding from a surface of the tapered table 42; and an upper wall part 22 which opposes tips of a plurality of the heat radiation fins 50 with intervals. The surface of the tapered table 42 is inclined so as to be displaced to the upper wall part 22 side along a direction in which the refrigerant flows.SELECTED DRAWING: Figure 1

Description

  The technology disclosed in the present specification relates to a boiling cooling apparatus.

  A boiling cooling device is known that includes an inlet through which a refrigerant flows, an outlet through which the refrigerant flows out, and a boiling device through which the refrigerant flows from the inlet toward the outlet. The boiling device has a bottom wall portion whose outer surface is thermally connected to the heating element, a plurality of radiating fins protruding from the inner surface of the bottom wall portion, and an upper wall facing the tips of the plurality of radiating fins with a space therebetween Part. The flow rate of the refrigerant in the boiling device is, for example, due to the resistance of the radiation fins, rather than the region from the inner surface of the bottom wall portion to the tips of the plurality of radiation fins (that is, the region where the radiation fins are present). To the inner surface of the upper wall portion (that is, a region where there is no radiating fin). Such a flow velocity difference makes it easier for the refrigerant to boil in the radiating fin, and a large amount of heat can be recovered from the heating element. An example of such a boiling cooling device is disclosed in Patent Document 1.

JP 2013-16589 A

  In the boiling cooling device, bubbles are generated on the surface of the heat radiation fins when the refrigerant boils. At this time, if the generated bubbles continue to adhere to the inner surfaces of the radiating fin and the bottom wall, contact between the new refrigerant and the radiating fin is hindered, and the cooling performance may be deteriorated. In this specification, the technique which can accelerate | stimulate that a bubble detach | leaves from the inner surface of a radiation fin and a bottom wall part is provided.

  The boiling cooling device disclosed in the present specification includes an inlet through which a refrigerant flows, an outlet through which the refrigerant flows out, and a boiling device through which the refrigerant flows from the inlet toward the outlet. The boiling device has a bottom wall portion whose outer surface is thermally connected to the heating element, a plurality of radiating fins protruding from the inner surface of the bottom wall portion, and an upper wall facing the tips of the plurality of radiating fins with a space therebetween Part. At least a part of the inner surface of the bottom wall portion from which the plurality of radiating fins protrudes is inclined so as to be displaced toward the upper wall portion along the direction in which the refrigerant flows.

  Here, the terms “bottom wall” and “upper wall” do not limit the direction in which the boiling device is installed. Therefore, for example, the boiling device may be installed in such a direction that the bottom wall portion is located above and the upper wall portion is located below. The term “bottom wall portion whose outer surface is thermally connected to the heating element” is not limited to the case where the outer surface of the bottom wall portion is in direct contact with the heating element. Other objects may be interposed between the outer surface of the bottom wall portion and the heating element as long as they are connected in a state where heat can be transferred.

  In the boiling cooling device, at least a part of the inner surface of the bottom wall portion is inclined so as to be displaced toward the upper wall portion along the direction in which the refrigerant flows. Therefore, when the refrigerant flowing in from the inlet hits the above-described inclination, the direction of the refrigerant flow changes, and a refrigerant flow is formed in a direction away from the inner surface of the bottom wall portion and the radiation fin. By forming such a refrigerant flow, bubbles attached to the inner surface of the bottom wall portion and the radiating fin are easily separated from the inner surface of the bottom wall portion and the radiating fin. Therefore, according to the boiling cooling device, it is possible to promote the separation of bubbles from the inner surfaces of the heat dissipating fins and the bottom wall portion.

The figure explaining the structure of the boiling cooling device of an Example. The figure which illustrates a mode that a bubble isolate | separates from a radiation fin.

(Example)
FIG. 1 shows a boiling cooling device 2 of this embodiment. The boiling cooling device 2 is a cooling device that cools the heating element 60 by boiling the refrigerant flowing in the boiling device 16 by the heat of the heating element 60. In the present embodiment, LLC (Long Life Coolant) used for cooling a vehicle engine is used as the refrigerant. In other examples, other refrigerants may be used. The heating element 60 to be cooled is, for example, a switching element.

  The boiling cooling device 2 includes an inlet 12, an outlet 14, and a boiling device 16. The inlet 12 is a refrigerant inlet. The refrigerant flows into the boiling device 16 through the inlet 12. As shown in FIG. 1, a partition plate 13 is provided at the inlet 12, and the refrigerant inflow path is divided into two. The outlet 14 is a refrigerant outlet. The refrigerant in the boiler 16 flows out through the outlet 14. Arrows F1 to F6 in FIG. 1 indicate the flow of the refrigerant. In the boiling device 16, the refrigerant mainly flows in the positive direction of the X axis of the coordinate system in FIG. Hereinafter, the positive direction side of the X axis may be referred to as “downstream side”, and the negative direction side of the X axis may be referred to as “upstream side”. In this embodiment, the diameter of the inlet 12 is larger than the diameter of the outlet 14. In another example, the diameter of the inlet 12 and the diameter of the outlet 14 may be substantially equal.

  The boiling device 16 includes a housing 20, a heat radiating plate 40, a taper base 42, and a plurality of heat radiating fins 50. The housing 20 is a box-shaped case that constitutes the main body of the boiling device 16. The housing 20 includes an upper wall part 22, a bottom wall part 24, an upstream side wall part 26, a downstream side wall part 28, and side wall parts 30 and 32.

  The upper wall portion 22 is a wall portion that is parallel to the XY plane of the coordinate system in FIG. 1 and is located on the positive side of the Z axis among the wall portions of the boiling device 16. Hereinafter, the positive direction side of the Z axis in FIG. 1 may be referred to as “upper side” and the negative direction side of the Z axis may be referred to as “lower side”. The outlet 14 is formed on the downstream side of the upper wall portion 22. The bottom wall portion 24 is a wall portion that is parallel to the XY plane and located on the lower side. An opening 34 is formed in the bottom wall portion 24. The upstream side wall portion 26 is a wall portion that is parallel to the YZ plane and located on the upstream side. The inlet 12 is formed in the upstream side wall portion 26. The downstream side wall portion 28 is a wall portion that is parallel to the YZ plane and located on the downstream side. The side wall portions 30 and 32 are each a wall portion parallel to the XZ plane.

  The heat radiating plate 40 is a plate-like member and is disposed on the inner surface of the bottom wall portion 24. The heat radiating plate 40 is disposed so as to close the opening 34 of the bottom wall portion 24. As a result, the refrigerant flowing in the boiling device 16 is prevented from leaking out from the opening 34. When the boiling cooling device 2 is used, the heating element 60 is brought into contact with the outer surface of the heat radiating plate 40 (that is, the surface on the negative direction side of the Z axis in the drawing). Further, the heat radiating plate 40 can be removed from the inner surface of the bottom wall portion 24 while the boiling cooling device 2 is not used.

  The taper base 42 is fixed to the inner surface of the heat radiating plate 40 (that is, the surface on the positive direction side of the Z axis). The back surface of the taper base 42 (that is, the surface on the negative direction side of the Z axis) is fixed so as to cover the substantially central portion of the inner surface of the heat radiating plate 40. The surface of the taper base 42 (that is, the surface on the positive side of the Z axis) is displaced upward (that is, on the upper wall portion 22 side) along the direction in which the refrigerant flows (that is, the directions of arrows F3 and F4 in FIG. 1). So as to be inclined. The combination of the heat sink 40 and the taper base 42 and the bottom wall portion 24 in this embodiment is an example of the “bottom wall portion” in the claims. The surface of the taper base 42 is an example of “the inner surface of the bottom wall”.

  Each of the plurality of heat radiation fins 50 is a member that protrudes upward from the surface of the taper base 42. Hereinafter, when each of the plurality of heat radiation fins 50 is referred to without distinction, it may be simply referred to as “heat radiation fin 50”. The radiation fin 50 is formed in a pin shape. The tips of the radiating fins 50 are opposed to the upper wall portion 22 with a space therebetween. In the present embodiment, each radiating fin 50 is provided to be inclined toward the downstream side with respect to the direction in which the refrigerant flows (that is, the directions of arrows F3 and F4 in FIG. 1) in accordance with the inclination of the taper base 42. . The radiating fins 50 are arranged at a constant interval from each other. A part of the refrigerant that has flowed into the boiling device 16 flows between the radiation fins 50 (see arrow F4 in FIG. 1). Since the heat of the heating element 60 is transmitted to each radiation fin 50 through the radiation plate 40 and the taper base 42, each radiation fin 50 becomes high temperature. Therefore, when the refrigerant flowing between the radiating fins 50 touches the radiating fins 50 and the taper base 42, the refrigerant recovers (ie, absorbs heat) from the heat radiating fins 50 and the taper base 42 and boils.

  When the refrigerant boils at the radiating fins 50 and the taper base 42, bubbles (that is, a gas phase refrigerant) are generated on the surfaces of the radiating fins 50 and the taper base 42. At this time, if the generated bubbles continue to adhere to the surface of the taper base 42 and the radiation fins 50, the contact between the new refrigerant and the radiation fins 50 is hindered, and the cooling performance may be deteriorated. In particular, as shown in FIG. 2, when the generated bubble B <b> 1 is trapped between the two radiating fins 50 due to surface tension, the bubbles are difficult to separate from the surface of the taper base 42 and the radiating fins 50. Become.

  However, in the boiling cooling device 2 of the present embodiment, the surface of the taper base 42 is inclined so as to be displaced upward along the direction in which the refrigerant flows. For this reason, as shown in FIG. 2, when the refrigerant (see arrow F <b> 10 in FIG. 2) that flows in from the inlet 12 and flows to the vicinity of the radiating fin 50 hits the above inclination, the direction of the refrigerant flow changes, A refrigerant flow is formed in a direction away from the surface of the taper base 42 and the radiation fins 50 (see arrow F11). By forming such a refrigerant flow, bubbles adhering to the surface of the taper base 42 and the heat radiation fins 50 are pushed from the lower side to the upper side, and are easily separated from the surface of the taper base 42 and the heat radiation fins 50 ( References B1 and B2). Therefore, according to the boiling cooling device 2 of the present embodiment, it is possible to promote the separation of bubbles from the surface of the taper base 42 and the heat radiating fins 50. As a result, a decrease in cooling performance can be suppressed.

  As mentioned above, although the specific example of the technique disclosed by this specification was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

(Modification 1) In the above embodiment, the boiling device 16 is installed in such an orientation that the bottom wall portion 24 is located on the lower side and the upper wall portion 22 is located on the upper side. The installation direction of the boiling device 16 is not limited to this, and can be arranged in an arbitrary direction. For example, the boiling device 16 may be installed in such an orientation that the bottom wall portion 24 is located on the upper side and the upper wall portion 22 is located on the lower side. Also in this case, the boiling cooling device can exhibit the effect of promoting the separation of bubbles from the surface of the taper base 42 and the heat radiating fins 50, as in the above-described embodiment.

(Modification 2) In the above-described embodiment, the radiating fin 50 is formed in a pin shape. The shape of the radiating fin is not limited to this, and may have an arbitrary shape such as a plate shape.

(Modification 3) The positions of the inlet 12 and the outlet 14 are not limited to the positions disclosed in the above embodiments. The inlet 12 and the outlet 14 may be formed at arbitrary positions as long as the refrigerant in the boiler 16 is formed so as to flow in the positive direction of the X axis in the vicinity of the radiation fins 50.

(Modification 4) In the above embodiment, the entire surface of the taper base 42 on which the heat radiating fins 50 are provided is inclined. However, the present invention is not limited thereto, and in the case where a plurality of heat radiation fins are provided on the inner surface of the heat sink, only a part of the region where the plurality of heat sink fins are provided on the inner surface of the heat sink may be inclined. .

(Modification 5) In the above embodiment, the outer surface of the heat radiating plate 40 is in direct contact with the heating element 60. Not limited to this, as long as the outer surface of the heat radiating plate 40 and the heating element 60 are thermally connected (that is, connected in a state where heat can be transferred), other heat sink 40 is connected between the outer surface of the heat radiating plate 40 and the heating element 60. An object may intervene.

(Modification 6) In the above embodiment, the heat sink 40 is formed separately from the bottom wall 24. However, the heat radiating plate 40 may be formed integrally with the bottom wall 24.

(Modification 7) In the above-described embodiment, the heat radiating plate 40 is disposed inside the boiling device 16. However, the present invention is not limited to this, and a part of the heat radiating plate 40 may be disposed outside the boiling device 16 as long as the heat radiating plate 40 can close the opening 34 of the boiling device 16. In this case, it is only necessary that at least the inclined range of the heat radiating plate 40 and the taper No. 42 protrudes from the inner surface of the bottom wall portion 24 to the upper wall portion 22 side.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2: Boiling cooling device 12: Inlet 13: Partition plate 14: Outlet 16: Boiler 20: Housing 22: Upper wall part 24: Bottom wall part 26: Upstream side wall part 28: Downstream side wall part 30: Side wall part 32: Side wall Portion 34: Opening 40: Radiation plate 42: Tapered base 50: Radiation fin 60: Heating element

Claims (1)

An inlet through which refrigerant flows,
An outlet through which the refrigerant flows;
A boiler through which the refrigerant flows from the inlet toward the outlet;
The boiling device has a bottom wall portion whose outer surface is thermally connected to a heating element, a plurality of radiating fins protruding from the inner surface of the bottom wall portion, and a front end of the plurality of radiating fins with a space therebetween. And an upper wall portion to be
At least a part of the inner surface of the bottom wall portion from which the plurality of radiating fins protrudes is inclined so as to be displaced toward the upper wall portion along the direction in which the refrigerant flows.
Boiling cooler.

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