JP2011228149A - Ebullient cooling type led lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ebullient cooling type LED lighting device capable of stably cooling a light source unit through prevention of dry out.SOLUTION: In the ebullient cooling type LED lighting device structured by including a light source unit 3 with an LED 9 as a light source, an ebullient cooling unit 5 equipped with a heat-receiving part 12 receiving heat from the light source unit 3, a heat-radiating part 13 radiating heat received at the heat-receiving part 12 toward outside, and a circulation route for circulating cooling media between the heat-radiating part 13 and the heat-receiving part 12, and a housing for containing the ebullient cooling unit 5 and the light source unit 3, the heat-radiating part 13 of the ebullient cooling unit 5 is arranged at an upper end of the heat-receiving part 12 shifted sideways. To be more concrete, the heat-radiating part 13 of the ebullient cooling unit 5 is arranged at a side positioned further upward than the heat-receiving part 12 in the case the latter 12 is leaned against the vertical direction.

Description

  The present invention relates to a boil-cooled LED lighting device that employs a boil-cooling system that exhibits high cooling capacity by phase change of a refrigerant.

  In recent years, lighting devices such as vehicular headlamps and outdoor lighting lamps have been changed from those using a high-intensity lamp such as a xenon lamp or sodium lamp as a light source to those using a long-life and low-power consumption LED as a light source. Replacement is progressing, and higher output is desired for LED lighting devices using LEDs as light sources.

  By the way, currently popular xenon lamps have a large output of about 200 W to 2000 W, and the power input to the LED lighting device as a substitute for this tends to increase. Recently, the power input to one LED lighting device is increasing. The thing whose electric power exceeds 200W has been developed.

  Since the amount of heat generated by the LED light source unit increases as the power of the LED lighting device increases, a cooling structure for driving the temperature lower and stably in an LED light source whose life and output change depending on the temperature. It is an important development issue.

  For example, Patent Document 1 proposes a water-cooled LED lighting device. This water-cooled LED lighting apparatus employs a method of cooling the heat of an LED light source by liquid cooling, and is a lamp body constituted by an LED light source and a water-cooled jacket that receives heat from the LED light source by a refrigerant liquid. A radiator that radiates the received refrigerant liquid to the outside air and a fan, and a pump that circulates the refrigerant liquid in the circulation path.

  According to such a water-cooled LED lighting device, the coolant liquid flows from the lamp body to the heat radiating section after receiving heat from the lamp body section, and repeats a circulation operation to return to the lamp body section after radiating heat to the outside air in the heat radiating section. Since the part is cooled, the LED light source can have high output and long life, and the radiator can efficiently dissipate heat, so that the heat dissipating part can be reduced in size and weight.

  However, in the water-cooled LED lighting device proposed in Patent Document 1, a large temperature difference may occur between the coolant liquid inlet and the outlet, particularly depending on the path of the coolant liquid circulating in the water-cooling jacket. There is a possibility that the temperature of the entire LED light source formed by arranging the LED becomes non-uniform, resulting in a variation in the luminous efficiency and lifetime of the LED. In this case, the temperature difference tends to increase as the heat receiving amount and the heat receiving area of the water cooling jacket increase.

  In addition, since the refrigerant liquid circulates in the circulation path by the pump, when the pump stops for some reason, the circulation of the refrigerant liquid also stops, and the water cooling jacket may be insulative, leading to a serious failure.

  Furthermore, since the lamp unit and the heat radiating unit are connected by a rubber hose made of butyl rubber or the like, it is necessary to provide a reserve tank in the circulation path for evaporating the refrigerant liquid from the rubber hose and compensating for the evaporation amount. Although the size of the reserve tank varies depending on the maintenance interval, a large reserve tank is required to lengthen the maintenance interval, which causes a problem that the LED lighting device is increased in size and weight.

  Therefore, the present applicant has previously proposed a boil-cooled LED lighting device 101 as shown in FIG. 9 that employs a boil-cooling system that exhibits a high cooling capacity by the phase change of the refrigerant (in Japanese Patent Application No. 2009-265876). .

  FIG. 9 is a longitudinal sectional view of the boiling cooling type LED lighting apparatus previously proposed by the present applicant. The boiling cooling type LED lighting apparatus 101 shown in FIG. 9 includes a light source unit 103 and an LED drive inside a rectangular box-shaped housing 102. The circuit 104, the boiling cooler 105, and the fan 106 are incorporated.

  The boiling cooler 105 includes a heat receiving portion 112 as an evaporator, a heat radiating portion 113 as a condenser disposed above the heat receiving portion 112, and a circulation path for circulating a refrigerant between the heat radiating portion 113 and the heat receiving portion 112. It is comprised including. Here, the heat receiving portion 112 is configured by a flat rectangular hollow plate having a jacket structure, and is housed in a vertically standing state in the housing 102. A refrigerant is accommodated inside the heat receiving portion 112, the light source unit 103 is disposed in close contact with the front surface, and the LED drive circuit 104 is disposed in close contact with the back surface. That is, the heat receiving unit 112 is disposed between the light source unit 103 and the LED drive circuit 104 while being sandwiched between them.

  The heat dissipating part 113 has a large number of cooling fins and is formed long in the width direction as a radiator structure, which is arranged on both sides (front and rear) of the upper end of the housing 102 with the heat receiving part 112 as a boundary. Has been.

  The fan 106 is on both sides of the heat receiving portion 112 of the boiling cooler 105, and between the light source unit 103 and the heat radiating portion 113 and between the LED drive circuit 104 and the heat radiating portion 113 in the vertical direction. It is arranged.

  Thus, when the boiling cooling type LED lighting apparatus 101 configured as described above is activated and power is supplied to the light source unit 103, the LED drive circuit 104, and the fan 106, a plurality of LEDs of the light source unit 103 emit light. The light passes through the lens 107 and is irradiated toward the front of the front side to illuminate the front. However, the lighting control of the light source unit 103 is performed by the LED drive circuit 104. Various electronic components of the LED drive circuit 104 generate heat, but these are forcibly cooled by the boiling cooler 105 and the temperature rise is suppressed.

  That is, in the heat receiving part 112 of the boiling cooler 105, in addition to normal heat conduction due to the temperature difference between the light source unit 103 and the LED drive circuit 410 and the refrigerant, the latent heat of vaporization when the refrigerant boils (evaporates) and vaporizes. Are deprived from the light source unit 103 and the LED drive circuit 104, so that the light source unit 103 and the LED drive circuit 104 are efficiently cooled. The refrigerant boiled and vaporized in the heat receiving unit 112 of the boiling cooler 510 rises as bubbles and pushes the liquid refrigerant in the heat receiving unit 112 to the heat radiating unit 113 by the bubble pump effect. A circulating flow of refrigerant is generated.

JP 2009-129642 A

  However, in the boiling cooling type LED lighting apparatus 101 shown in FIG. 9, since the refrigerant circulates using gravity, the heat radiation performance is easily influenced by the direction, and the installation direction of the boiling cooling type LED lighting apparatus 101 is There was a problem that was limited.

  That is, in the boiling cooling type LED lighting device 101 shown in FIG. 9, since the heat radiating portion 113 of the boiling cooler 105 is arranged on both the front and rear sides of the heat receiving portion 112 in the upper part in the housing 102, as shown in FIG. 10. When the boiling-cooled LED lighting device 101 is tilted forward, for example, by the angle θ shown in the figure with respect to the vertical direction, the refrigerant liquid is accumulated in a portion of the heat radiating portion 113 in front of the heat receiving portion 112, and the refrigerant liquid is near the heat receiving portion 112. Because it disappears, it falls into a dry out state. When such a dry-out occurs, the circulation of the refrigerant liquid is delayed, so that the heat cannot be transported from the heat receiving part 112 to the heat radiating part 113 and the heat radiating function of the heat radiating part 113 is lost. The problem that the cooling performance of the boiling cooler 105 falls occurs.

  The present invention has been made in view of the above problems, and an object thereof is to provide a boil-cooled LED lighting device that can stably cool a light source unit by preventing the occurrence of dryout. .

In order to achieve the above object, the invention according to claim 1
A light source unit using an LED as a light source;
A heat receiving portion that receives heat from the light source unit, a heat radiating portion that radiates heat received by the heat receiving portion to the outside air, and a boiling cooler that includes a circulation path for circulating a refrigerant between the heat radiating portion and the heat receiving portion;
A housing for housing the boiling cooler and the light source unit;
In a boil-cooled LED lighting device comprising:
The heat dissipating part of the boiling cooler is arranged close to one end at the upper end of the heat receiving part.

  According to a second aspect of the present invention, in the first aspect of the invention, the heat radiating portion of the boiling cooler is disposed on a side located above the heat receiving portion when the heat receiving portion is inclined with respect to the vertical. It is characterized by that.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, at least a part of the heat receiving portion of the boiling cooler is provided with an inclined portion that is inclined with respect to the vertical, and the heat radiating portion is provided at an upper end of the inclined portion. And the light source unit is disposed in close contact with one side of the inclined portion.

  According to the present invention, the heat radiating part of the boiling cooler is moved to one side to the upper end of the heat receiving part, for example, when the heat receiving part is tilted with respect to the vertical, the heat radiating part is moved closer to the side positioned above the heat receiving part. Therefore, even if the boiling cooling type LED lighting device (heat receiving part) is tilted to a certain angle with respect to the vertical, the liquid refrigerant does not accumulate in the heat radiating part, and the dry out due to the liquid refrigerant accumulating in the heat radiating part. Generation is prevented, the light source unit is stably cooled by the boiling cooler, and the temperature rise is prevented, and the light emission efficiency and life of each LED constituting the light source unit are increased.

It is a perspective view of the boiling cooling type LED lighting apparatus which concerns on this invention. It is a perspective view of the state where the housing of the boil cooling type LED lighting device concerning the present invention was removed. It is sectional drawing of the heat receiving part and heat dissipation part of the boiling cooler with which the boiling cooling type LED lighting device which concerns on this invention was equipped, Comprising: (a) shows the state installed vertically, (b) is perpendicular | vertical Shows the state tilted forward. It is typical sectional drawing for demonstrating the effect | action of the boiling cooler with which the boiling cooling type LED lighting apparatus which concerns on this invention was equipped. It is a figure which shows the relationship between the inclination angle of the boiling cooling type | mold LED illuminating device which concerns on this invention, and a thermal radiation performance in contrast with the conventional one. It is a side view of the boiling cooling type LED lighting apparatus which concerns on another form of this invention. It is a sectional side view of the boil cooling type LED lighting apparatus which concerns on another form of this invention. It is principal part sectional drawing which shows the usage condition of the boiling-cooling type LED illuminating device which concerns on this invention, (a) is a usage pattern as a downlight, (b) is a figure which respectively shows the usage pattern as an upper light. It is a longitudinal cross-sectional view of the conventional boiling cooling type LED lighting apparatus. It is a longitudinal cross-sectional view which shows the state which inclined the conventional boil cooling type LED lighting apparatus with respect to perpendicular | vertical.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a perspective view of a boil-cooled LED lighting device according to the present invention, FIG. 2 is a perspective view of the boil-cooled LED lighting device with a housing removed, and FIG. 3 is provided in the boil-cooled LED lighting device. FIG. 4 is a cross-sectional view of the heat receiving part and the heat radiating part of the boiling cooler, in which (a) shows a state of being installed vertically, (b) is a figure showing a state of being tilted forward with respect to the vertical, FIG. These are typical sectional drawings for demonstrating the effect | action of the same boiling cooler.

  A boiling cooling type LED lighting apparatus 1 shown in FIG. 1 is configured by incorporating a light source unit 3, an LED drive circuit 4, a boiling cooler 5, and a fan 6 shown in FIG. 2 inside a rectangular box-shaped housing 2.

  The housing 2 is made of a resin such as PC or a metal such as aluminum. As shown in FIG. 1, a rectangular transparent lens 7 covering the front of the light source unit 3 is fitted into the front surface 2a. Yes. A rectangular exhaust port 8 that is long in the width direction is formed on substantially the entire upper surface of the housing 2. Although not shown, a plurality of louver-like air inlets are formed on the rear surface of the housing 2.

  As shown in FIG. 2, the light source unit 3 is configured by mounting a plurality of LEDs 9 serving as light sources on a LED substrate 10 in a matrix shape, and is housed in a vertically standing state on the front side in the housing 2. Has been.

  Further, as shown in FIG. 2, the LED drive circuit 4 is configured by mounting a plurality of various electronic components 11 on a circuit board, and constitutes a part of the boiling cooler 5 in the housing 2. It is housed in a vertically standing state on the back side opposite to the side on which the light source unit 3 is disposed with a heat receiving part 12 described later interposed therebetween.

  As schematically shown in FIG. 4, the boiling cooler 5 includes a heat receiving portion 12 as an evaporator, a heat radiating portion 13 as a capacitor disposed above the heat receiving portion 12, the heat radiating portion 13 and the heat receiving portion. The circulation path is configured to circulate the refrigerant between the parts 12, and the circulation path is integrally formed in the vertical direction beside the passage in the heat receiving part 12, the passage in the heat radiating part 13, and the heat receiving part 12. It is constituted by a passage 14.

  The heat receiving portion 12 is configured by a flat rectangular hollow plate having a jacket structure, and a refrigerant is accommodated therein. As the refrigerant, fluorocarbon or fluoroketone, which is an alternative chlorofluorocarbon, general ethylene glycol or propylene glycol other than the alternative chlorofluorocarbon is used, and the internal pressure is adjusted when the boiling cooler 5 is manufactured (when the refrigerant is charged). Controls the boiling point of the refrigerant.

  Thus, the heat receiving portion 12 is stored in the housing 2 in a vertically upright state as described above, but the light source unit 3 is disposed in close contact with the front surface, and the LED drive is disposed on the rear surface. The circuit 4 is arranged in close contact. That is, the heat receiving unit 12 is disposed between the light source unit 3 and the LED drive circuit 4 while being sandwiched between them.

  Further, the heat dissipating part 13 has a large number of cooling fins and is formed long in the width direction as a radiator structure, which is arranged on one side (this embodiment) at the upper end of the heat receiving part 12 as shown in FIG. For example, when the heat receiving unit 12 (boiling cooled LED lighting device 1) is inclined by an angle θ with respect to the vertical as shown in FIG. It is arranged close to the side located above 12. That is, the heat radiating portion 13 is extended at a right angle toward the rear at the upper end portion of the heat receiving portion 12.

  Here, the “heat receiving” portion 12 and the heat radiating portion 13 are both made of an aluminum material that is lightweight and has a high heat transfer coefficient, and both are joined and integrated by brazing. Moreover, more than half of the internal space of the boiling cooler 5 is filled with the liquid refrigerant.

  Incidentally, as shown in FIG. 4, in the boiling cooler 5, the refrigerant outlet 12 a that opens at the upper part of the heat receiving part 12 and the refrigerant inlet 13 a that opens at the lower part of the heat radiating part 13 are in direct communication with each other. The refrigerant outlet 13b that opens to the opposite side of the refrigerant inlet 13a and the refrigerant inlet 12b that opens to the lower part of the heat receiving portion 12 are in communication with each other via a return passage 14, thereby forming a refrigerant circulation path. Yes. In the present embodiment, as shown in FIG. 2, the heat radiating portion 13 is lowered toward the return passage 14 such that the refrigerant outlet 13b is positioned below the refrigerant inlet 13a (see FIG. 4). B) It is arranged slightly inclined with respect to the horizontal.

  As shown in FIG. 2, a plurality of the fans 6 are arranged in parallel in the width direction (lateral direction) below the heat radiating portion 13 of the boiling cooler 5.

  Thus, when the boiling cooling type LED lighting apparatus 1 configured as described above is activated and power is supplied to the light source unit 3, the LED drive circuit 4, and the fan 6, the plurality of LEDs 9 of the light source unit 3 emit light. The light passes through the lens 7 and is irradiated toward the front of the front side to illuminate the front. However, the lighting control of the light source unit 3 is performed by the LED drive circuit 4, and the LED 9 of the light source unit 3 and Various electronic components 11 of the LED drive circuit 4 generate heat, and the light source unit 3, the LED drive circuit 4, and the housing 2 that houses them are overheated to raise their temperatures.

  However, in the present embodiment, the light source unit 3 and the LED drive circuit 4 are forcibly cooled by the boiling cooler 5 to suppress the temperature rise, and the intake port (not shown) formed on the back surface of the housing 2 by the fan 6. The housing 2 and the LED drive circuit 4 are forcibly air-cooled by the outside air introduced into the housing 2 from the outside and the temperature rise is suppressed.

  That is, in the heat receiving part 12 of the boiling cooler 5, in addition to normal heat conduction due to the temperature difference between the light source unit 3 and the LED drive circuit 4 and the refrigerant, the latent heat of vaporization when the refrigerant boils (evaporates) and vaporizes. Are deprived of the light source unit 3 and the LED drive circuit 4, so that the light source unit 3 and the LED drive circuit 4 are efficiently cooled.

  And the refrigerant | coolant which boiled and vaporized in the heat receiving part 12 of the boiling cooler 5 rose as a bubble, as shown by the arrow in FIG. 4, and the liquid refrigerant in the heat receiving part 12 is radiated by the bubble pump effect. In order to push out to 13, the circulating flow of the refrigerant | coolant of the direction shown by the arrow in FIG.

  Thus, the gas refrigerant vaporized by boiling is condensed and liquefied by releasing heat to the outside air in the heat radiating portion 13, but the heat radiation from the refrigerant in the heat radiating portion 13 is caused by the outside air passing through the heat radiating portion 13. Promoted. That is, outside air is sucked into the housing 2 from the air inlet of the housing 2 by the fan 6 rotating in the housing 2, and the sucked outside air rises while cooling the housing 2 and the LED drive circuit 4, and the heat radiating portion 13. , The heat is discharged from the exhaust port 8 of the housing 2 to the outside, and the heat radiation from the refrigerant in the heat radiating portion 13 is promoted by the outside air passing through the heat radiating portion 13.

  In addition to the bubble pump effect, the refrigerant condensed and liquefied in the heat radiating portion 13 flows toward the refrigerant outlet 13b along the inclination of the heat radiating portion 13 due to gravity, and flows into the return passage 14 from the refrigerant outlet 13b. 12 is sent.

  Thereafter, the same operation is repeated, and the refrigerant circulates in the circulation path while repeating the boiling and condensation phase change, and these take away the latent heat of evaporation accompanying the boiling in the heat receiving unit 12 from the light source unit 3 and the LRD drive circuit 4. To cool efficiently.

  In the above, in the boiling cooling type LED lighting device 1 according to the present embodiment, the heat radiating part 13 of the boiling cooler 5 is brought to one side to the upper end of the heat receiving part 12, specifically, the heat receiving part 12 is perpendicular to the vertical direction. As shown in FIG. 3 (b), when it is inclined forward by an angle θ, it is arranged close to the side positioned above the heat receiving part 12, so that the boil cooling type LED lighting device 1 (heat receiving part 12) is arranged. ) Is tilted to a certain angle (actually about 70 °) with respect to the vertical, the liquid refrigerant does not accumulate in the heat radiating portion 13, and the occurrence of dryout due to the liquid refrigerant accumulating in the heat radiating portion 13 occurs. Thus, the light source unit 3 is stably cooled by the boiling cooler 5 to prevent the temperature from rising, and the luminous efficiency and life of each LED 9 constituting the light source unit 3 are increased.

  Here, when the boiling-cooling type LED lighting device 1 (heat receiving part 12) according to the present invention is tilted with respect to FIG. 6, the inclination angle θ [deg] and the heat radiation performance (the temperature [° C.] of the heat radiation part 13). ) In comparison with that of the conventional boiling-cooled LED lighting device 101 shown in FIG. 9, the boiling-cooled LED lighting device 1 according to the present invention is dry-out until the inclination angle θ is about 70 °. It can be seen that substantially constant heat dissipation performance is obtained. On the other hand, in the conventional boil-cooled LED lighting device 101, when the inclination angle θ exceeds 35 °, the heat dissipation performance is significantly reduced, the temperature of the heat dissipation part 113 rapidly increases, and the inclination angle θ exceeds 40 °. It can be seen that dryout occurs.

  Next, another embodiment of the present invention will be described with reference to FIGS.

  6 is a side view of a boil-cooled LED lighting device according to another embodiment of the present invention, FIG. 7 is a side sectional view of the boil-cooled LED lighting device, and FIG. 8 is a usage pattern of the boil-cooled LED lighting device. It is principal part sectional drawing, Comprising: (a) is a figure which shows the usage type as a downlight, (b) is a figure which shows the usage type as an upper light, respectively.

  The boil-cooled LED lighting device 1 ′ according to the present embodiment is attached to the stay 15 that bends in the shape of a letter “<” in a side view and is inclined to the inclined portion 15 </ b> A of the stay 15. As shown in FIG. 7, the light source unit 3, the LED drive circuit 4, the boiling cooler 5, and the fan 6 are accommodated inside the attached housing 2.

  Here, the boiling cooler 5 includes a heat receiving portion 12, a heat radiating portion 13 disposed obliquely above the upper end portion of the heat receiving portion 12 (upwardly perpendicular to the longitudinal direction of the heat receiving portion 12), and the heat radiating portion 13. And the heat receiving part 12 including a circulation path for circulating the refrigerant. The heat radiating part 13 is brought to one side (in the embodiment, obliquely upward) at the upper end of the heat receiving part 12, and specifically, the heat receiving part. The portion 12 is disposed so as to face a direction perpendicular to the longitudinal direction of the portion 12.

  Thus, even if it is attached in a state inclined with respect to the vertical as in the boil-cooled LED device 1 ′ according to the present embodiment, the heat radiating portion 13 is connected to the upper end of the heat receiving portion 12 on one side (this In the embodiment, the liquid refrigerant is not accumulated in the heat radiating portion 13, and the occurrence of dry-out is prevented, and the light source unit 3 is stably cooled by the boiling cooler 5. Is done.

  Such a boil-cooled LED lighting device 1 ′ can be used for, for example, a downlight or an upper light. When used as a downlight, the boil-cooled LED lighting device 1 ′ receives heat from the light source unit 3 as shown in FIG. When the light source unit 3 is disposed on the lower surface side of the portion 12 and used as an upper light, the light source unit 3 may be disposed on the upper surface side of the heat receiving portion 12 as shown in FIG.

  In the above embodiment, only the LED drive circuit 4 is forcedly cooled by the outside air. However, if the light source unit 3 is also forcedly cooled by the outside air at the same time, cooling by the boiling cooler 5 and the fan 6 are performed. The light source unit 3 can be cooled more efficiently by the hybrid cooling method with forced air cooling.

DESCRIPTION OF SYMBOLS 1 Boiling cooling type LED lighting apparatus 2 Housing 2a Front surface of housing 3 Light source unit 4 LED drive circuit 5 Boiling cooler 6 Fan 7 Lens 8 Exhaust port 9 LED
DESCRIPTION OF SYMBOLS 10 LED board 11 Electronic component 12 Heat receiving part 12a Refrigerant outlet of heat receiving part 12b Refrigerant inlet of heat receiving part 13 Heat radiating part 13a Refrigerant inlet of heat radiating part 13b Refrigerant outlet of heat radiating part 14 Return path 15 Stay 15A Stay inclination part

Claims (3)

A light source unit using an LED as a light source;
A heat receiving portion that receives heat from the light source unit, a heat radiating portion that radiates heat received by the heat receiving portion to the outside air, and a boiling cooler that includes a circulation path for circulating a refrigerant between the heat radiating portion and the heat receiving portion;
A housing for housing the boiling cooler and the light source unit;
In a boil-cooled LED lighting device comprising:
The boiling cooling type LED lighting device, wherein the heat radiating portion of the boiling cooler is arranged close to one end on the upper end of the heat receiving portion.   The boiling cooling type LED lighting device according to claim 1, wherein the heat radiating part of the boiling cooler is arranged on a side located above the heat receiving part when the heat receiving part is inclined with respect to the vertical. . At least a part of the heat receiving part of the boiling cooler is provided with an inclined part that is inclined with respect to the vertical, the heat radiating part is extended upward at a right angle at the upper end of the inclined part, and the one side of the inclined part is The boil-cooling type LED lighting device according to claim 1, wherein the light source unit is disposed in close contact.

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