The present invention relates to a cooler.
In addition to a cooler for performing a heat exchange by carrying a cooling fluid to the inside so as to cool an object to be cooled arranged on a surface of the cooler, there is another cooler where the object to be cooled is arranged in a thermal transmission member and cooling is performed by spraying the cooling fluid towards the thermal transmission member.
Japanese Patent Laying-Open No. 3-30457 discloses a cooling method of a semiconductor device for supplying and vaporizing predetermined liquid in a heat generating unit of the semiconductor device so as to cool the heat generating unit by latent heat in vaporization thereof. According to this cooling method of the semiconductor device, it is possible to improve cooling efficiency and reliability of the semiconductor device, to simplify and downsize a cooling structure, and to prevent corrosion and contamination due to the cooling fluid.
Japanese Patent National Publication No. 2001-521138 discloses a device for performing two-phase cooling with regard to a cooling device for an electronic element. This two-phase cooling device has a first housing unit, a second housing unit and a third housing unit. One or more spraying nozzle is fixed to an inner surface of the second housing unit, and further, one or more electronic element with high power is installed at a position facing the spraying nozzle on an outer surface. In the second housing unit, cooling liquid is sprayed from the spraying nozzle by a pump. When the cooling liquid is brought in contact with a heating part of the second housing unit, a part of the cooling liquid is converted into vapor and the remaining part of the cooling liquid is returned to the first housing unit in a liquid state.
Japanese Patent Laying-Open No. 2005-86204 discloses a spray cooling system where a main body including a sealed spraying chamber and a thermal transmission wall having an inside surface serving as a border of the thermal transmission wall is provided in a system for cooling a component with a sprayed cooling fluid. In this spray cooling system, an outside surface of the thermal transmission wall is retained relative to a part of the component. A spray is arranged to spray the cooling fluid to the inside surface. It is possible to efficiently install this spray cooling system in a plurality of places within a complicated system.
In the cooler for spraying the cooling fluid, the cooling can be mainly performed by the latent heat in vaporization at the time of vaporizing the cooling fluid. Alternatively, the object to be cooled is cooled by carrying the cooling fluid while taking heat off at the time of spraying the cooling fluid towards the thermal transmission member.
In order to uniformly cool the object to be cooled, at least an area of the thermal transmission member where the object to be cooled is arranged is preferably uniformly cooled. In order to evenly cool the thermal transmission member, the cooling fluid is preferably evenly arranged on a surface of the thermal transmission member.
In a spray cooling module disclosed in Japanese Patent Laying-Open No. 2005-86204 mentioned above, the spray is controlled by a controller and the cooling is performed while spraying by the precise amount. However, in this published patent literature, there is no examination on uniformization of drops on the surface of the thermal transmission wall to be sprayed with the cooling fluid. That is, there is not examination on an action of the cooling fluid after sprayed to the thermal transmission member even when the spraying amount is controlled. There is a problem that unless a state of the drops on the surface of the thermal transmission member is uniform after spraying the cooling fluid, it is not possible to uniformly cool the object to be cooled.
It is an object of the present invention to provide a cooler capable of performing uniform cooling.
A cooler based on the present invention includes a thermal transmission member having a surface to be sprayed with a cooling fluid. The thermal transmission member includes a first channel formed on the surface, and a second channel intersecting with the first channel, the second channel being formed on the surface.
Preferably in the above invention, the first channel is formed to supply the cooling fluid to a substantially entire part of the surface. The first channel is formed to discharge an excessive amount of the cooling fluid. The second channel is formed to facilitate evaporation of the cooling fluid.
Preferably in the above invention, in the second channel, a section perpendicular to an extending direction of the second channel is formed into a stepwise shape.
Preferably in the above invention, in the thermal transmission member, the surface is formed into a convex surface so that a height is gradually reduced from a center part to an outer peripheral part.
Preferably in the above invention, in the thermal transmission member, the surface is inclined so that a height is gradually reduced from a center part to an outer peripheral part.
Preferably in the above invention, each of the first channel and the second channel is formed into a groove shape. At least one channel of the first channel and the second channel is formed to be gradually deepened from a center part to an outer peripheral part of the surface.
Preferably in the above invention, the second channel is formed into a groove shape. The second channel is formed so that at least a part of the second channel generates a capillary phenomenon.
Preferably in the above invention, each of the first channel and the second channel is formed into a groove shape so that the first and second channels have bottom surfaces respectively. The bottom surface of the second channel is formed to be lower than the bottom surface of the first channel.
According to the present invention, it is possible to provide the cooler capable of performing the uniform cooling.
It should be noted that two or more configurations among the configurations described above may be properly combined. That is, proper selection and combination of a part or the entire configurations described above is obviously taken into consideration.
With reference to
A heat generating body 12 serving as an object to be cooled is arranged on a surface of thermal transmission member 1. Heat generating body 12 is connected to a main surface of thermal transmission member 1. In the present embodiment, heat generating body 12 is arranged in a center part of the main surface of thermal transmission member 1.
The cooler in the present embodiment is provided with a spray 11. Spray 11 is arranged to face a main surface of thermal transmission member 1 on the opposite side of the main surface where heat generating body 12 is arranged. Spray 11 is arranged apart from thermal transmission member 1. Spray 11 is formed to spray a cooling fluid 21. That is, spray 11 is formed to jet cooling fluid 21 in a drop shape. Spray 11 is formed to spray cooling fluid 21 towards the main surface of thermal transmission member 1 on the opposite side of the main surface where heat generating body 12 is arranged. In the present embodiment, liquid is used as the cooling fluid.
First groove 1a and second groove 1b in the present embodiment are formed so that extending directions thereof intersect with each other. First groove 1a communicates with second groove 1b. Heat generating body 12 is arranged in an area corresponding to a substantially center part of an area where first groove 1a and second groove 1b are formed.
In the present embodiment, there are formed a plurality of first grooves 1a. First groove 1a is formed in a substantially entire part of the surface of thermal transmission member 1. First groove 1a is formed in a linear shape. First groove 1a is formed to have a clearance between first grooves 1a. First groove 1a in the present embodiment is formed at an equal interval. First groove 1a is formed so that extending directions of first grooves 1a are parallel to each other. First groove 1a is formed to extend from one end surface of thermal transmission member 1 to the other end surface. First groove 1a is formed to discharge an excessive amount of the supplied cooling fluid to the outside of thermal transmission member 1.
In the present embodiment, there are formed a plurality of second grooves 1b. Second groove 1b is formed in a linear shape. Second groove 1b is formed to have a clearance between second grooves 1b. Second groove 1b in the present embodiment is formed at an equal interval. Second groove 1b is formed so that extending directions of second grooves 1b are parallel to each other. Second groove 1b is formed so that lengths of second grooves 1b in the extending directions are substantially the same as each other.
Ends of second groove 1b are arranged in an area inside the main surface of thermal transmission member 1. Second groove 1b is formed so as not to reach the end surfaces of thermal transmission member 1. Second groove 1b is formed so as not to discharge the cooling fluid to be supplied to the inside from the ends of second groove 1b.
With reference to
Depth d2 of second groove 1b in the present embodiment is formed to be larger than depth d1 of first groove 1a. That is, bottom surface 9b of second groove 1b is formed to be at a lower position than bottom surface 9a of first groove 1a.
With reference to
With reference to
In a case where the cooling fluid is locally in short, the cooling fluid is carried through first groove 1a and second groove 1b and into a shortage point. Therefore, it is possible to substantially uniformly supply the cooling fluid. For example, even in a case where even spraying is not performed from spray 11 towards thermal transmission member 1 due to a transient change and the spraying is disproportionately performed over an area, it is possible to substantially uniformly distribute the cooling fluid through first groove 1a and second groove 1b and substantially uniformly cool the thermal transmission member.
In such a way, the cooler in the present embodiment is provided with the thermal transmission member. The thermal transmission member includes the first channel formed on the surface to be sprayed with the cooling fluid and the second channel intersecting with the first channel. By this configuration, it is possible to substantially uniformly arrange the cooling fluid over the entire area where the first groove and the second groove are formed. The thermal transmission member is substantially uniformly cooled in the area where the first groove and the second groove are formed. As a result, it is possible to substantially uniformly cool a member to be cooled.
With reference to
In the present embodiment, the first groove is formed to supply the cooling fluid to a substantially entire part of the surface of the thermal transmission member and further to discharge an excessive amount of the cooling fluid. Meanwhile, second groove 1b is formed to facilitate the evaporation of the cooling fluid. By this configuration, the first channel is a channel for mainly supplying the cooling fluid over the entire groove and the second channel is a channel for mainly performing the evaporation. In such a way, it is possible to divide into a plurality of channels having functions respectively and to reduce a change in a cooling performance when the spraying amount is changed.
With reference to
As shown in
A structure of facilitating the evaporation of the second groove is not limited to any of these structures above. For example, a porous material may be arranged on the surface of the second groove. Alternatively, as the structure of facilitating the evaporation of the second groove, a part serving as an edge or a part serving as a difference may be formed in the section as mentioned above. A whisker may be charged in the second groove.
The second groove may be formed so that at least a part thereof generates a capillary phenomenon. By this configuration, the cooling fluid is moved along the second groove due to the capillary phenomenon and it is possible to arrange the cooling fluid over a substantially entire part of the second groove. For example, width of the second groove may be formed to be small enough to generate the capillary phenomenon.
The ends of the second groove in the present embodiment are arranged inside the main surface of the thermal transmission member. However, the present embodiment is not limited to this mode but the ends of the second groove may be formed to reach the end surfaces of the thermal transmission member. By this configuration, it is possible to directly discharge an excessive amount of the cooling fluid supplied to the second groove without carrying through the first groove.
The first groove and a part of the second groove in the present embodiment are formed to have a section in a U-letter shape. However, the present embodiment is not limited to this mode but the section may be formed in an arbitrary shape. For example, the section may be formed in a V-letter shape.
The thermal transmission member in the present embodiment is formed in a plate shape. However, the present embodiment is not limited to this mode but the thermal transmission member may be formed into an arbitrary shape. For example, the thermal transmission member is not limited to a plate shape but may be formed in a rectangular parallelepiped. The thermal transmission member is not limited to one material but preferably formed by a material excellent in thermal conduction.
In the present embodiment, the object to be cooled is arranged on the surface of the thermal transmission member. However, the present embodiment is not limited to this mode but the thermal transmission member may be formed as a part of the object to be cooled. For example, the first channel and the second channel may be formed on a surface of a casing of the object to be cooled and the cooling fluid may be sprayed towards this surface.
The cooler in the present invention can be applied to a cooler for performing the cooling of an arbitrary object to be cooled.
With reference to
Thermal transmission member 2 in the present embodiment has a first groove 2a serving as the first channel and a second groove 2b serving as the second channel. First groove 2a and second groove 2b are formed on a surface to be sprayed with the cooling fluid. First groove 2a and second groove 2b are formed to intersect with each other. First groove 2a communicates with second groove 2b.
Heat generating body 12 serving as the object to be cooled in the present embodiment is arranged on a main surface on the opposite side of the main surface where first groove 2a and second groove 2b are formed. Heat generating body 12 is arranged in a substantially center part of an area corresponding an area where first groove 2a and second groove 2b are formed.
There are formed a plurality of first grooves 2a. First groove 2a is formed in a linear shape. First groove 2a is formed so that extending directions of first grooves 2a are formed into a radial shape. First groove 2a is formed to extend from a center of a circle in the plan of thermal transmission member 2 to an outer periphery. An outside end of first groove 2a reaches an end surface of thermal transmission member 2. First groove 2a is formed to discharge an excessive amount of the cooling fluid to the outside.
There are formed a plurality of second grooves 2b. Second groove 2b is formed to extend in a substantially circular shape in planar view. Second groove 2b has a closed shape in planar view. There are formed a plurality of second grooves 2b in a concentric shape in planar view. Second groove 2b is formed at an equal interval. Second groove 2b is formed so as not to reach the end surface of thermal transmission member 2.
Even in the cooler in the present embodiment, it is possible to substantially uniformly arrange the cooling fluid in the area where the first groove and the second groove of the thermal transmission member are formed and to substantially uniformly cool the object to be cooled.
The other configurations, an operation and an effect are the same as the first embodiment and a description thereof will not be repeated.
With reference to
Thermal transmission member 3 is formed so that a height of a surface to be sprayed with cooling fluid 21 is gradually lowered from a center part towards an outer peripheral. The surface of thermal transmission member 3 is inclined. Thermal transmission member 3 is formed so that a part facing spray 11 is the thickest and thermal transmission member 3 is gradually thinning towards an outer periphery. Thermal transmission member 3 is also formed so that the center part is the thickest and thermal transmission member 3 is gradually thinning towards the outer peripheral part even in the direction along the second groove. Spray 11 is arranged right above the center part of thermal transmission member 3.
A first groove 3a is formed along the surface facing spray 11. First groove 3a is formed so that depth is constant. First groove 3a is formed to reach end surfaces of thermal transmission member 3. A second groove (not shown) is formed so that depth is constant and further so as to reach the end surfaces of thermal transmission member 3.
In the first cooler in the present embodiment, cooling fluid 21 sprayed from spray 11 is carried towards the outer peripheral part in first groove 3a as shown by an arrow 32. Since the surface of thermal transmission member 3 where the first groove and the second groove are formed is formed into a convex surface, it is possible to discharge an excessive amount of the cooling fluid by gravitational force.
First groove 4a is formed to reach end surfaces of thermal transmission member 4. The second groove (not shown) is formed to reach the end surfaces of thermal transmission member 4. In thermal transmission member 4, a surface at the time of cutting by a surface along an extending direction of the second groove is formed into a substantially arc shape. Spray 11 is arranged right above a thickest part of thermal transmission member 4.
In the second cooler in the present embodiment, it is also possible to discharge an excessive amount of cooling fluid 21 towards the outside by the gravitational force as shown by an arrow 33.
In the thermal transmission member in the present embodiment, the surface in the extending direction of the first groove and the extending direction of the second groove is formed into a convex surface. However, the present embodiment is not limited to this mode but a section in one direction of the extending direction of the first groove and the extending direction of the second groove may be formed into a convex shape.
The other configurations, an operation and an effect are the same as the first embodiment and a description thereof will not be repeated.
With reference to
A first groove 5a serving as the first channel and a second groove 5b serving as the second channel are formed on a surface of thermal transmission member 5 to be sprayed with the cooling fluid. First groove 5a and second groove 5b are respectively formed into a linear shape. First groove 5a and second groove 5b are formed to intersect with each other.
There are formed a plurality of first grooves 5a. First grooves 5a are formed apart from each other so that a clearance between first grooves 5a is at a substantially equal interval. There are arranged a plurality of second grooves 5b. Second grooves 5b are formed apart from each other so that a clearance between second grooves 5b is at substantially equal interval.
Thermal transmission member 5 in the present embodiment has discharge groove 5c and 5d formed to surround an area where first groove 5a and second groove 5b are formed.
Discharge groove 5c is formed to communicate with first groove 5a. Discharge groove 5c is formed to extend in the direction substantially perpendicular to an extending direction of first groove 5a. Discharge groove 5c is arranged in both ends of first groove 5a. Discharge groove 5d is formed to communicate with second groove 5b. Discharge groove 5d is formed to extend in the direction substantially perpendicular to an extending direction of second groove 5b. Discharge groove 5d is arranged in both ends of second groove 5b. Discharge groove 5c and 5d extend up to end surfaces of thermal transmission member 5. Discharge grooves 5c and 5d are formed to discharge the cooling fluid to the outside of thermal transmission member 5.
In first groove 5a in the present embodiment, depth is gradually deepened from a center part towards an outer peripheral part of the surface of thermal transmission member 1. That is, the surface of thermal transmission member 1 is formed in a plan shape and first groove 5a is gradually deepened towards discharge groove 5c. As well as first groove 5a, second groove 5b is formed to be gradually deepened towards discharge groove 5d.
The cooling fluid is sprayed from spray 11 towards thermal transmission member 5. In the present embodiment, the cooling fluid sprayed to first groove 5a is carried towards discharge groove 5c as shown by an arrow 36. An excessive amount of the cooling fluid in first groove 5a is guided to discharge groove 5c. In such a way, since the depth is gradually deepened from the center part to the outer peripheral part, it is possible to actively discharge the excessive amount of the cooling fluid. With reference to
In second groove 5b, the excessive amount of the cooling fluid is guided to discharge groove 5d. The excessive amount of the cooling fluid carried into discharge groove 5d is discharged from thermal transmission member 5 as shown by an arrow 35.
In the present embodiment, the first groove and the second groove are formed to be gradually deepened towards the outside of the thermal transmission member. However, the present embodiment is not limited to this mode but one groove of the first groove and the second groove may be formed to be gradually deepened from the center part towards a peripheral part of the surface of the thermal transmission member.
The other configurations, an operation and an effect are the same as the first embodiment and a description thereof will not be repeated.
In the above drawings, the same or corresponding parts are given the same reference numerals.
It should be noted that the embodiments disclosed here are not restrictive but an example in all respects. A scope of the present invention is not shown by the above description but claims. The present invention should include all variations within similar meanings and ranges to the claims.
The present invention can be applied to a cooler for cooling a semiconductor element constituting an electric device (PCU: Power Control Unit) for controlling a rotating electric machine that drives a hybrid vehicle or the like.
Number | Date | Country | Kind |
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2006-163584 | Jun 2006 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2007/062199 | 6/12/2007 | WO | 00 | 12/11/2008 |