JP2022063819A - Local cooling device - Google Patents

Abstract

To provide a local cooling device capable of providing high-efficiency cooling for a local high load heating element.SOLUTION: The local cooling device keeps a temperature difference between the heat input and heat release surfaces to be dT≤10°C so that an electron cooling element can be driven with high efficiency by hybrid cooling between the electron cooling element and a radiator and by controlling a cooling flow path to minimize the relative front and back surface temperature difference within the electron cooling element.SELECTED DRAWING: None

Description

The present invention relates to a cooling device capable of highly efficiently cooling a locally high-load heating element, particularly a semiconductor laser.

Solution

By controlling the cooling flow path so as to minimize the temperature difference between the front and back sides of the electronic cooling element and the hybrid cooling of the electronic cooling element and the radiator, the heat input surface and heat dissipation that can drive the electronic cooling element with high efficiency. The surface temperature difference dT ≦ 10 ° C is suppressed.

Japanese Unexamined Patent Publication No. 2019-37757

FIG. 3 shows a conventional embodiment.
The server rack system (hybrid system 10 incorporating a conduction system and a convection system) is a combination of a server rack 11 for accommodating a server 12 and a heat transfer device, and includes a server rack and a heat sink in the form of a housing. , A thermal contact structure 13, 14 for thermal contact between the server rack and the heat sink, and a cooler 19 for providing a source of coolant for cooling the server rack, both conductive heat transfer and convection heat transfer. Removes heat from the server rack and keeps the server rack within a predetermined temperature range.

However, in order to locally cool a high heating element such as a semiconductor laser (hereinafter abbreviated as LD) to room temperature or lower, a cooling means such as Pelche is required. However, if Pelche cooling does not dissipate heat with high efficiency, since Pelche itself is a high thermal conductor, high temperature heat is conducted to the cooling part on the front and back, so the cooling capacity decreases. Therefore, the temperature difference dT ≦ 10 ° C. on both sides of Pelche must be as high as possible, but it is difficult to obtain the temperature difference dT ≦ 10 ° C. with high capacity and high efficiency by Pelche alone.

Solution

In order to solve this problem, the present invention controls the hybrid cooling of the electronic cooling element and the radiator, the cooling flow path so as to minimize the relative front and back temperature difference in the electronic cooling element, and further electronic cooling of Pelche and the like. By suppressing the temperature difference dT ≤ 10 ° C between the heat input surface and the heat radiation surface where the element can be driven with high efficiency, it is possible to highly efficiently cool even a high heat density and high load heating element such as a high output LD. ..

The invention's effect

As described above, the invention according to claim 1 to 4 of the present invention cools with high efficiency for a high load device such as a high output LD or a current control device that locally generates a large amount of heat. can.

And, compared with the conventional forced air-cooled heat sink and heat dissipation by Pelche, the cooling capacity of high output LD etc. is more than doubled, so the laser output with the same high output LD is more than doubled. Can be given.

1A and 1B are overall configuration views of the laser apparatus according to the first embodiment of the present invention, where FIG. 1A is a top view, FIG. 1B is a side view, FIG. 1C is a cross-sectional view taken along the line AA, and FIG. Is.

2A and 2B are overall configuration views of the laser apparatus according to the second embodiment of the present invention, where FIG. 2A is a top view, FIG. 2B is a sectional view taken along the line XX, and FIG. 2C is a sectional view taken along the line YY. Is a top view and (e) is a sectional view taken along the line AA. FIG. 3 is a conventional embodiment. FIG. 4 shows the cooling capacity characteristics of Pelche.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
This will be described with reference to the numbers of FIGS. 1 and 2.

Embodiment 1

1A and 1B are overall configuration views of a laser apparatus according to a first embodiment of the present invention, where FIG. 1A is a top view, FIG. 1B is a side view, FIG. 1C is a cross section taken along the line AA, and FIG. 1D is a side view. It is a figure.

The drainage ports 103 from the heat exchange section 102 in which the electronic cooling element Pelche 101 (thick wire) is built, and the drainage 105 drained from 104 are cooled by the radiator 108 air-cooled by the fan 107 via the pump 106 and then heated. By receiving water into the water inlet 110 of the heat exchange unit 102 via the water inlet pipe 109 to the exchange unit 102, the heat exchange unit 102 has a hybrid cooling configuration of cooling at the heat exchange unit 102 and cooling at the radiator 108.

The cooling function of the heat exchange unit 102 will be described in such a configuration.
A copper plate 112, which is a high thermal conductor, is adhered to the entire surface of the Pelche 101 on the endothermic side 111 of the Pelche 101 with a high thermal conductive paste 113.
The heat dissipation side 115 of the Pelche 114 (thick wire) having a smaller area than the Pelche 101 is further adhered to the copper plate 112 by the high thermal conductive paste 113.
The endothermic side 116 of the Pelche 114 is again adhered to the copper plate 117 with the high thermal conductive paste 113, and further cools the local high heating element 118 such as the LD.

Next, the heat exhaust function of the heat exchange unit 102 will be described. The circulating water 119 cooled by the radiator 108 and invading from the water inlet 110 flows into the central portion of the heat radiation side 120 of the Pelche 101. After that, while passing through the partition plates 121 arranged in a staggered pattern, the heat from the Pelche 101 is absorbed and becomes high temperature water, which is discharged from the drainage ports 103 and 104.

Since water has the largest heat capacity and is difficult to heat, even if the entire heat dissipation side 120 of Pelche 101 is simply submerged, heat conduction is slight. The reason for this is that because a laminar flow is formed, the flow velocity on the surface of Pelche 101 becomes close to 0, the low flow velocity part of this laminar flow becomes a heat conduction wall, the temperature rise is small, and heat is generated near the surface of Pelche 101. It was presumed that the cooling efficiency was low due to muffled air. Therefore, if the number of partition plates 121 arranged in a staggered pattern is increased to increase the channel length by 5 times, the temperature rise will increase by 6 to 10 times, and when 20 W of electric power is applied to Pelche 101, the temperature will be 10 ° C or higher. I was able to raise it. It is considered that this is because the flow velocity increases and becomes turbulent due to the addition of many partition plates 121 arranged in a staggered pattern, and the heat dissipation due to the increase in the flow velocity on the surface of Pelche 101 increases.

On the other hand, the cooling efficiency of the radiator 108 sharply increases as the temperature difference between the internal water temperature and the room temperature increases. In this embodiment, when 20 W is supplied to Pelche 101 and 10 W is supplied to Pelche 101 and a heat load of 10 W is applied to the local high heating element 118 and adjusted to 20 ° C., the temperature difference in the radiator 108 becomes 10 ° C. or more, which is efficient. I was able to cool it. The temperature difference in the radiator 108 has many parameters such as the passage of time, the posture, size and shape of each component, each interface state and room temperature distribution, and changes greatly depending on them, so detailed measurement conditions are omitted. do.

Further, although the Perche 101 is driven by the Perche power supply 122, the radiator 108 rotates the fan 107 so as to take in the radiator 108 so that the heat from the Perche power supply 122 does not enter the radiator 108, but the radiator 108 and the fan Even if the order of 107 was reversed, there was almost no difference in the temperature difference of 10 ° C. in the radiator 108. This is because when the radiator 108 is blown from the fan 107, the flow velocity increases, but the heat generated by the fan 107 is added. Since it is not affected by heat generation, it is considered that the difference was hardly observed in the temperature difference of 10 ° C. in the radiator 108 after all.

Further, if the Pelche 101 is lengthened or a large number of partition plates 121 arranged in a staggered pattern are added, the exhaust heat from the Pelche 101 becomes large, and the temperature difference in the radiator 108 can be further increased, so that the cooling capacity is further increased. do.

Further, in the first embodiment, in order to increase the cooling capacity of the locally high heating element 118 arranged in the central portion, the circulating water 119 from the radiator 108 is taken in from the central portion, but the LD which is the local high heating element 118 is taken in. The water inlet 110 may be moved so as to be closest to the installation position of.

Further, it is obvious that the LD drive capacity can be further increased by inserting a heating element such as an LD driver into the water channel 124 to the radiator 108 as a water-cooled heating element 123. Further, instead of adhering the second Pelche 114 to the copper plate 112, a local high heating element 118 may be adhered instead.

Further, when the local high heating element 118 was removed from the copper plate 117 and optimized for a no-load state, a temperature difference of 30 ° C. or more was obtained for both Pelche 101 and Pelche 114. Therefore, when the circulating water temperature is set to 10 ° C., an extremely low temperature of 10 ° C.-30 ° C. × 2 = −50 ° C. can be expected.

2A and 2B are overall configuration views of the laser apparatus according to the second embodiment of the present invention, where FIG. 2A is a top view on the high temperature side, FIG. 2B is a sectional view taken along the line XX, and FIG. 2C is a sectional view taken along the line YY. (D) is a top view on the low temperature side, and (e) is a sectional view taken along the line AA.
The difference from the first embodiment is that the LD, which is a local high heating element, is a water-cooled LD50 and provides a configuration for cooling with high efficiency when water cooling is required.

The drainage 105 drained from the drain port 52 from the heat exchange section 51 in which the Pelche 101 is built is cooled by the radiator 108 air-cooled by the fan 107 via the pump 106, and then via the water inlet pipe 109 to the heat exchange section 51. Since water is introduced into the water inlet 53 of the heat exchange unit 51, the heat exchange unit 51 has a hybrid cooling configuration of cooling by the heat exchange unit 51 and cooling by the radiator 108.

The cooling function of the heat exchange unit 51 will be described in such a configuration.
As shown in the upper surface view (d) on the low temperature side of FIG. 2, the circulating water 54 that has returned from the water inlet pipe 109 and has entered from the water inlet 53 is a square having a porous water channel 55 adhered to the endothermic side 111 of the Pelche 101. It is cooled by the copper material 56.

The circulating water 57 after passing through the porous water channel 55 passes through the water channel 58 in the shaded portion, again through the second porous water channel 59 of the square copper material 56, passes through the water channel 60 in the dotted portion, and then is a local high heating element. Water enters the water-cooled LD50 through the water inlet 62 in the water-cooled base 61 which is closely fixed to the water-cooled LD50. The water inlet 53 and the dotted water channel 60 are separated by a separating plate 63.

The circulating water 64 discharged from the water-cooled LD50 passes through the drainage channel 65 in the water-cooled base 61, and then passes through the double diagonal channel 66 leading from the low-temperature endothermic side 111 of the Pelche 101 to the high-temperature radiating side 120. Water has entered the high temperature heat dissipation side 120 of 101. After that, while passing through the partition plate 67 arranged in a staggered pattern, a large amount of heat from the heat radiation side 120 of the Pelche 101 is absorbed, becomes high temperature water, and is discharged from the drain port 52.

Next, the improvement of the efficiency of the water cooling capacity in this embodiment will be described with reference to Graph 1 of FIG. Generally, it is known that in order to increase the cooling efficiency of Pelche, it is necessary to make the temperature difference dT between the heat dissipation side and the endothermic side of Pelche 101 as close to 0 as possible. Graph 1 of FIG. 4 shows the cooling capacity characteristics of the Pelche 101 held in this embodiment. The COP on the vertical axis is the cooling amount / input power ratio, and the horizontal axis is the current.

For example, if the current is 5A and dT = 10 ° C. (red line), COP = 3.3, which is 3.3 times the cooling capacity of the input power. At 5A, at dT = 0 ° C., COP> 4, and the efficiency is further improved.
That is, although high efficiency can be obtained by setting dT ≦ 10 ° C., in both Examples 1 and 2 of the present invention, dT that cannot be realized by Pelche alone under a high load due to the hybrid configuration of radiator cooling and Pelche cooling. ≦ 10 ℃ could be realized by the present invention.

Next, the principle in which dT ≦ 10 ° C. is realized on the entire surface of Pelche 101 even under a high load in the present invention will be described with reference to FIG.
The temperature of the circulating water 54 that has entered from the water inlet 53 is set to T1 = 30 ° C. The circulating water 54 is cooled by the square copper material 56 having the perforated water channels 55 and 59, and the current of the Pelche 101 is applied so that the water temperature at the time of passing through the water inlet 62 in the water cooling base 61 becomes the temperature T2 = 20 ° C. Adjust with the power supply 122.
Next, the current of the water-cooled LD50 is adjusted so that the water temperature T3 of the circulating water 64 discharged from the water-cooled LD50 becomes T3 = 30 ° C.

The circulating water 64 adjusted to the water temperature T3 = 30 ° C. enters the heat dissipation side 120 of the Pelche 101 through the double diagonal channel 66. Therefore, the dT in the region 1 of the Pelche 101 is almost 0.

After that, a large amount of heat from the Pelche 101 is absorbed while passing through the partition plate 67 arranged in a staggered pattern, and T4 = 40 ° C. in the region 4. Since the temperature T3 on the opposite surface of the Pelche 101 in the region 4 is 30 ° C., dT = 40-30 = 10 ° C. That is, since dT ≦ 10 ° C. can be controlled over the entire surface of Pelche, high load and high efficiency heat dissipation can be realized.

(Reference) The main test environment used in Example 1 is shown.
Pelche 101 ・ ・ ・ Fellow Tech 9506 □ 55x55x4.8mm
Maximum rating 40A 4.3V Qc92W
Local high heating element 118 ... Peak 2.4kW at270A Duty 2%
66Hz at 0.3ms
Maximum heat generation ... (270A x 15.2V-2.4kW) x 0.02 =
(4.1kW-2.4kW) x 0.02 = 34W
Fan size ・ ・ ・ □ 120x120x40mm 15W
Radiator size ・ ・ ・ □ 120x120x20mm
Pump ・ ・ ・ Maximum discharge pressure 10Kpa, maximum flow rate 400ml / min

As described above, the inventions according to claims 1 to 4 of the present invention have high efficiency for high-load devices such as high-power semiconductor lasers and current control devices, which generate a large amount of heat locally. Can be cooled with.
Compared with the conventional forced air-cooled heat sink and heat dissipation by Pelche, the laser output could be more than doubled in the same laser output. For example, it was confirmed that a laser that was conventionally 50 mJ 20 Hz can be driven at 50 Hz or higher.
Furthermore, due to the high-speed response of Pelche, cooling control can be performed at high speed against load fluctuations, which greatly improves the stability of laser output, etc. Also, since Pelche can be configured in a cascade configuration, an extremely low temperature of <-50 ° C is expected. can. Since such an extremely low temperature has a capacity exceeding the heat cycle temperature test condition of -40 ° C for electronic components, a high-speed and compact compact temperature tester can be realized by using it in combination with laser heating or the like.

50 ... Water-cooled LD
51 ... Heat exchange unit 52 with a built-in Pelche 1 ... Drain port 53 ... Water inlet 54 ... Circulating water 55 ... Porous water channel 56 ... Square copper material 57 ... Circulating water 58 ... Water channel 59 ... Second porous water channel 60 ... Point-shaped water channel 61 ... Water cooling base 62 ... Water inlet water channel 63 ... Separation plate 64 ... Circulating water 65 ... -Drainage channel 66 in the water cooling base 61 ... Double diagonal channel 67 ... Partition plate 101 arranged in a staggered pattern ... Pelche 102 ... Heat exchange section 103, 104 ... Drain port 105.・ ・ Drainage 106 ・ ・ ・ Pump 107 ・ ・ ・ Fan 108 ・ ・ ・ Radiator 109 ・ ・ ・ Water inlet pipe 110 ・ ・ ・ Water inlet 111 ・ ・ ・ Heat absorption side 112 of Pelche 1 ・ ・ ・ Copper plate 113 ・ ・ ・ High heat conduction Paste 114 ... Pelche 115 having a smaller area than Pelche 1 ... Heat dissipation side 116 of Pelche 14 ... Heat absorption side 117 of Pelche 14 ... Copper plate 118 ... Local high heating element 119 ... Water inlet Circulating water 120 that has invaded from 10 ... Heat dissipation side of Pelche 1 ... Partition plate 122 arranged in a staggered pattern ... Pelche power supply 123 ... Water-cooled heating element 124 ... Water channel

Claims (4)

A plurality of straightening vanes are arranged in the space provided on the heat radiation side of the plate-shaped electronic cooling device to provide a long-distance heat radiation side cooling water channel. On the other hand, a high thermal conductive material is attached to the endothermic side of the electronic cooling device. Local cooling is characterized in that the temperature difference dT at each position of the heat radiation side cooling water channel and the high thermal conductive material is arranged so as to minimize the variation in the temperature difference dT at the front and back symmetrical positions with respect to the electronic cooling device. Device A plurality of straightening vanes are arranged in the space provided on the heat radiation side of the plate-shaped electronic cooling device to provide a long-distance heat radiation side cooling water channel. On the other hand, a high thermal conductive material having a porous water channel and a high thermal conductive material having a water channel for injecting and discharging water by fixing a water-cooled local high heat generating body are attached to the heat absorbing side of the electronic cooling device. ing.
The water cooled by passing through the high thermal conductive porous body having the porous water channel is sent to the end of the space provided on the heat dissipation side after passing through the high thermal conductive fixing table.
In the heat radiation side cooling water channel, the variation in the temperature difference dT at the symmetrical positions on the front and back sides is minimized with respect to the affixed surface of the high thermal conductive porous body attached to the endothermic side of the electronic cooling device. Local cooling device characterized by being arranged so as to be The arrangement of the straightening vanes, the control of the electronic cooling device, the flow rate, and the heat load were controlled so that the variation in the temperature difference at the front and back symmetrical positions was dT ≦ 20 ° C, preferably dT ≦ 10 ° C with respect to the electronic cooling device. The local cooling device according to claim 1 and 2, wherein the local cooling device is characterized by the above. The high-temperature drainage from the inclusion body of the electronic cooling device is cooled by a radiator and then returned to the water inlet hole of the inclusion body, whereby hybrid cooling that combines electronic cooling device type cooling and radiator type cooling is performed. The local cooling device according to claims 1 to 3.

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