WO2019087311A1

WO2019087311A1 - Heat radiation device

Info

Publication number: WO2019087311A1
Application number: PCT/JP2017/039431
Authority: WO
Inventors: 鈴木　隆; 純哉鷲足; 劉　軍; 篠崎　隆; 素行岡田
Original assignee: 学校法人上智学院; 株式会社ケーヒン; 株式会社エコラ・テック; 株式会社ファインテック
Priority date: 2017-10-31
Filing date: 2017-10-31
Publication date: 2019-05-09

Abstract

The present invention provides a heat radiation device and a refrigeration cycle which have improved heat radiation efficiency and can be made more compact. A core 21 is fitted into at least an inlet side of a tube 2-1, groove sections 23 are provided spirally on the outer circumference of the core 21, a spiral flow path 25 having a polygonal cross-section is provided between the groove sections 23 and the tube inner wall, and a heat radiation section 3 is provided on the outer circumference side of the spiral flow path 25.

Description

Heat dissipation device

The present invention relates to a heat dissipation device that includes a flow path and can efficiently dissipate the heat of fluid such as gas, gas-liquid two-phase fluid, or liquid flowing through the flow path to the outside.

Conventionally, in a heat dissipating device such as an automobile radiator, an oil cooler, an intercooler, a condenser of a car air conditioner, an evaporator, etc., the heat dissipating device is provided with a flow path for water or refrigerant to flow. The heat of the oil can be dissipated efficiently.
For example, as a condenser in an air conditioning apparatus, one that improves heat dissipation efficiency and achieves miniaturization is proposed (for example, see Patent Document 1).

JP, 2015-1317, A

However, in the prior art, the improvement of the heat dissipation efficiency is not sufficient. Therefore, it is desirable to significantly improve the heat dissipation efficiency.
And further miniaturization is desired for heat dissipation devices such as a radiator, an oil cooler, an intercooler, a condenser of a car air conditioner, and an evaporator.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a heat dissipation device capable of improving heat dissipation efficiency and achieving downsizing.

The present invention is characterized in that a polygonal tube is spirally wound to form a spiral flow passage having a polygonal cross section, and a heat dissipation portion is provided on the outer peripheral side of the spiral flow passage.
In the present invention, a core is fitted on at least the inlet side of a tube, and a spiral groove is provided on the outer periphery of the core, and a spiral flow passage having a polygonal cross section is provided between the groove and the inner wall of the tube. A heat dissipation unit is provided on the outer peripheral side of the spiral flow channel.
The grooves may be formed such that the pitch of the grooves is gradually narrowed toward the downstream.

In the present invention, the spiral flow channel generates a primary flow along the length direction of the flow channel and a secondary flow rotating in the cross section of the flow channel, and the cross section of the spiral flow channel is a pair of secondary flow The flow may be generated.
Moreover, the said thermal radiation part may be comprised with the thermal radiation fin.
It may be a radiator, an oil cooler, an intercooler, a radiator of any of a condenser of a refrigerating cycle, or an evaporator, and may be a radiator which is provided with the radiator according to any one of claims 1 to 4.
A compressor, a condenser, a decompression device, and an evaporator may be provided, and the condenser may be provided with the heat dissipation device according to any one of claims 1 to 4.

According to the present invention, the polygonal tube is spirally wound to form a spiral flow passage having a polygonal cross section, and the heat dissipation part is provided on the outer peripheral side of the spiral flow passage. In the cross section of the flow path, the flow is directed from the inner circumferential side toward the outer circumferential side having the heat radiating portion, heat is efficiently transmitted to the heat radiating portion on the outer circumferential side, and the heat radiation efficiency is improved.
In addition, a primary flow along the longitudinal direction of the flow channel and a secondary flow rotating in the cross section of the flow channel are generated inside the spiral flow channel, and the heat of the fluid flowing in the flow channel gets on the secondary flow In the cross section of the flow path, heat flows to the outside more efficiently if it flows from the inner peripheral side toward the outer peripheral side having the heat radiating portion. At this time, from the upstream to the downstream of the tube, a cold fluid can be stagnated in the inner central portion of the secondary flow, and the temperature of the fluid can be extremely lowered by the internal temperature addition in addition to the heat dissipation from the tube surface.

FIG. 1 is a view showing a refrigeration cycle according to a first embodiment. FIG. 2 is a view showing the heat dissipation device according to the first embodiment. FIG. 3 is a view showing a core of the heat dissipation device according to the first embodiment. FIG. 4 is an enlarged cross-sectional view showing a portion of arrow IX of FIG. FIG. 5 is a view showing a core of the heat dissipation device according to the second embodiment. FIG. 6 is a view showing the core of the heat dissipation device according to the third embodiment. FIG. 7 is a perspective view showing the heat dissipation device according to the fourth embodiment. FIG. 8 is a view showing a refrigeration cycle according to a fifth embodiment. FIG. 9A is a cross-sectional view showing a heat dissipation device according to a fifth embodiment, and FIG. 9B is a cross-sectional view of a rectifier. FIG. 10A is a cross-sectional view showing the eddy current generator of the fifth embodiment, and FIG. 10B is a cross-sectional view taken along the line BB in FIG. 10A.

First Embodiment
FIG. 1 shows a refrigeration cycle.
The code | symbol 7 is a compressor and the condenser 1 is connected to the discharge port of the compressor 7. As shown in FIG. A pressure reducing device 9 is connected to the condenser 1, and an evaporator 8 is connected to the pressure reducing device 9. The suction port of the compressor 7 is connected to the evaporator 8.

The condenser (heat radiation device) 1 according to the first embodiment includes a plurality of (six in the present embodiment) straight tubes 2-1 to 2-6 and a plurality of

radiation fins

3, 3, 3. Have.
The inlets of the two upstream tubes 2-1 and 2-2 are connected by a bifurcated inlet pipe 4. The outlet of the tube 2-1 is connected to the inlet of the tube 2-3 via a vent 5-1, and the outlet of the tube 2-2 is connected to the inlet of the tube 2-4 via a vent 5-2. The outlet of the tube 2-3 is connected to the inlet of the tube 2-5 via a vent 5-3, and the outlet of the tube 2-4 is connected to the inlet of the tube 2-6 via a vent 5-4. The outlets of the tubes 2-5, 2-6 are connected by a bifurcated outlet pipe 6. In addition, as long as appropriate sizing can be achieved with respect to the form of the tube and the form of the core to be described later, the inlet side is not necessarily limited to the two tubes.

As shown in FIG. 2, in the six tubes 2-1 to 2-6, the core 21 is disposed on the inlet side of the in-tube flow passage 12. The length of the tubes 2-1 to 2-6 is, for example, 300 mm, and the length L of the core 21 is, for example, 100 mm.
Since the configurations of the tubes 2-1 to 2-6 are the same, only the tube 2-1 is shown in FIG. 2 and the remaining tubes are not shown, and the description thereof is omitted.
The core 21 is fitted to at least the inlet side of the tube 2-1. As shown in FIG. 3, a groove portion 23 extending in a spiral shape and having a square cross section is formed on the outer peripheral portion of the core 21. The land portion 24 remaining in a spiral shape comes into close contact with the inner wall of the tube 2-1 when the core 21 is fitted to the inlet side of the tube 2-1.

Between the groove 23 of the core 21 and the inner wall of the tube 2-1, as shown in FIG. 2, a spiral flow channel 25 having a square cross section and extending in a spiral as a whole is formed.
A plurality of heat dissipating fins 3, 3,... Are attached to the outer peripheral portion of the tube 2-1 over the entire length of the tube 2-1, including the portion where the core 21 is fitted. .
When the core 21 has a long length L (see FIG. 3), the heat radiation effect is enhanced, but the flow path is narrowed by that amount, and thus the flow resistance is obtained. On the other hand, when the length L is short, the flow resistance decreases, but the heat radiation effect decreases accordingly. In addition, if the inclination θ (see FIG. 3) of the spiral groove portion 23 is small, the heat radiation effect is enhanced, but the flow path is narrowed by that amount, which is a flow resistance. On the other hand, when the inclination θ is large, the flow resistance decreases, but the heat radiation effect is reduced accordingly.
Therefore, the length L of the core 21 and the inclination θ of the spiral groove 23 are appropriately set in consideration of the heat dissipation effect and the loss due to the flow resistance.

Next, the operation of the first embodiment will be described.
The high temperature and high pressure gas refrigerant discharged from the compressor 7 flows into the two tubes 2-1 and 2-2 from the forked inlet pipe 4 at a predetermined flow rate.
The core 21 is disposed on the inlet side of the two tubes 2-1 and 2-2, and the liquid refrigerant is formed between the groove 23 of the core 21 and the inner wall of the tube 2-1. , And flows into a spiral channel 25 extending in a spiral shape as a whole and having a square cross section.

In the spiral flow passage 25, the liquid refrigerant generates a primary flow X (see FIG. 2) along the longitudinal direction of the spiral flow passage 25. This primary flow X forms a spiral flow.
Further, in the helical flow passage 25, as shown in FIG. 4 separately from the primary flow X, two (plural) secondary flows Y − that rotate in the square cross section of the helical flow passage 25. It turned out that 1 and Y-2 are generated.

The secondary flows Y-1 and Y-2 promote heat transfer to the

radiation fins

3, 3,. The mechanism of this heat transfer promotion was clarified.
The liquid refrigerant in the spiral flow channel 25 generates a primary flow X (a spiral flow), so that strong turbulence occurs on the outer peripheral side of the spiral flow channel 25. According to the simulation, it has been found that the cross section of the spiral flow passage 25 generates stronger turbulence on the outer peripheral side of the spiral flow passage 25 than the circular shape, for example, in the polygonal shape such as square.
In addition to the rectangular cross section, pentagonal, hexagonal and the like are included. When the cross section has a polygonal shape, a polygonal shape in which the shape of the outer peripheral portion approximates a circular shape is not preferable. The quadrangular shape includes a quadrangular shape in which the chamfered portion has an arc shape or a chamfered shape.
When the cross section has a square shape, the disturbance strength is 1.66 times as compared to the circular cross section. The occurrence of this strong disturbance promotes heat transfer to the

radiation fins

3, 3,... On the outer peripheral side of the spiral flow passage 25. When the heat transfer is promoted, the refrigerant is largely cooled on the outer peripheral side of the spiral flow passage 25, and the cooled refrigerant moves to the inner peripheral side of the helical flow passage 25 where the heat transfer is small. This movement generates secondary flows Y-1 and Y-2.
Also, due to the centrifugal force, the low density material moves to the inner peripheral side of the spiral flow channel 25. This movement also generates secondary flows Y-1 and Y-2. According to the simulation, the lubricating oil mixed in with the refrigerant was present only on the inner peripheral side of the spiral channel 25.

The secondary flows Y-1 and Y-2 form a pair of flows Y-1 and Y-2 in the cross section of the spiral channel 25. The heat transfer is promoted on the outer peripheral side of the spiral flow passage 25, and the largely cooled refrigerant moves to the inner peripheral side of the spiral flow passage 25 where the heat transfer is small. In addition, the low density portion of the refrigerant moves to the inner peripheral side of the spiral channel 25 by the centrifugal force. As a result of these movements, the low temperature refrigerant CR stagnates at the center of the cross section on the inner peripheral side of the spiral flow channel 25.
The secondary flows Y-1 and Y-2 are flows rotating in the cross section of the spiral flow passage 25. With the rotation of the refrigerant, the high temperature refrigerant HR is cooled on the outer peripheral side by heat transfer, moves to the inner peripheral side, and the heat radiation effect is enhanced by sequentially repeating this movement.
According to this promotion mechanism, the high temperature refrigerant HR always circulates on the outer peripheral side of the spiral flow passage 25 where the heat transfer is large, so the heat radiation effect is enhanced.

If the cross section of the spiral flow channel 25 is circular, even if a pair of secondary flows Y-1 and Y-2 are produced, there is no stagnation of cold refrigerant as in the polygonal shape, so the spiral flow channel 25 is A strong disturbance can not be expected on the outer peripheral side of the element, and a high heat radiation effect can not be expected.
In the present embodiment, the low temperature refrigerant CR stays in the center of the cross section on the inner peripheral side of the spiral flow channel 25 due to the pair of secondary flows Y-1 and Y-2, and the high temperature refrigerant HR goes to the outer peripheral side. Since the side is cooled and circulated to the inner side, the heat radiation effect is significantly enhanced.
Therefore, the condenser 1 can be miniaturized.

The cross section of the spiral channel 25 is not limited to the square shape. For example, a space for generating the pair of secondary flows Y-1 and Y-2 in the cross section of the spiral flow channel 25 and retaining the low temperature refrigerant CR in the center of the cross section on the inner peripheral side of the spiral flow channel 25 is provided. It may be any shape that can be secured. The cross section of the spiral channel 25 may be a polygon such as a quadrangle, a trapezoid, a pentagon, or a hexagon. The length of each side on the inner peripheral side and the outer peripheral side of the spiral flow channel 25 needs to be a predetermined length.

Second Embodiment
The second embodiment will be described with reference to FIG. For the sake of convenience of explanation, the same parts as those of the first embodiment are denoted by the same reference numerals, and the explanation thereof is omitted.
The core 21 of the second embodiment is formed such that the pitches P, P, P... Of the grooves 23 gradually narrow from upstream to downstream. In this case, the pitches P, P, P... May be narrowed from the upstream toward the downstream, and for example, the equal pitch may be continuous at the pitch P in the middle.
As shown in FIG. 1, the condenser 1 is connected to the discharge port of the compressor 7, and high temperature and high pressure gas refrigerant flows into the tubes 2-1 and 2-2 of the condenser 1. The gas refrigerant is cooled while passing through the spiral flow passage 25 of the core 21, and the liquid content of the refrigerant gradually increases. In the second embodiment, since the pitches P, P, P... Of the groove portion 23 gradually narrow from the upstream toward the downstream, the refrigerant which has become a gas-liquid two-phase by the increase in the liquid content of the refrigerant The cooling is efficiently performed through the narrow grooves 23 of the pitches P, P, P.
In another form, the pitches P, P, P... Narrow from upstream to downstream, widen in the middle, or randomly change the pitch. Even in this form, the refrigerant is cooled efficiently.

Third Embodiment
The third embodiment will be described with reference to FIG. For the sake of convenience of explanation, the same parts as those of the first embodiment are denoted by the same reference numerals, and the explanation thereof is omitted.
The condenser (heat dissipation device) 1 of the third embodiment is connected in the refrigeration cycle of FIG. In the condenser 1 according to the third embodiment, as shown in FIG. 6, polygonal tubes 121 are respectively joined to the inlet sides of six straight tubes 2-1 to 2-6. The polygonal tube 121 is configured by spirally winding a tube having a rectangular cross section. In the polygonal tube 121, a spiral channel 125 having a substantially square cross section is formed. Further, at the upstream end of the polygonal tube 121, a guide member 126 for guiding the refrigerant flowing from the upstream to the inlet of the spiral channel 125 of the polygonal tube 121 is disposed.

The high temperature and high pressure liquid refrigerant discharged from the compressor 7 flows into the spiral flow path 125 of the polygonal tube 121 via the guide member 126.
In the spiral channel 125, as in the first embodiment, a primary flow X along the longitudinal direction of the spiral channel 125 and two rotating in a square (square) cross section of the spiral channel 125. Secondary flows Y-1 and Y-2 are generated (see FIG. 4).
In the third embodiment, as in the first embodiment, according to the mechanism of heat transfer promotion to the

radiation fins

3, 3, 3 ... caused by the secondary flows Y-1, Y-2, the refrigerant has a helical flow The outer periphery of the passage 125 is largely cooled to enhance the cooling effect.
Therefore, the condenser 1 can be miniaturized.

The cross section of the spiral channel 125 is not limited to a square. For example, it may be configured to generate a pair of secondary flows Y-1 and Y-2 in the cross section of the spiral flow channel 125, and secure a space for retaining the low temperature refrigerant CR in the center of the cross section on the inner peripheral side. Just do it. The cross section of the spiral channel 125 may be trapezoidal, pentagonal, hexagonal or the like.

Fourth Embodiment
The fourth embodiment will be described with reference to FIG. For the sake of convenience of explanation, the same parts as those of the first embodiment are denoted by the same reference numerals, and the explanation thereof is omitted.
The condenser (heat radiation device) 1 of the fourth embodiment is configured by providing the

radiation fins

3, 3, 3... Directly on the outer periphery of the polygonal tube 121 of the third embodiment.
W indicates the width dimension of the radiation fin 3, L indicates the length dimension of the radiation fin 3, and H indicates the height dimension of the radiation fin 3.

Also in the fourth embodiment, in the spiral channel 125, as in the first embodiment, the primary flow X along the longitudinal direction of the spiral channel 125 and the square cross section of the spiral channel 125 are rotated. Two secondary flows Y-1 and Y-2 are generated (see FIG. 4).
And according to the mechanism of heat transfer promotion to the

radiation fins

3, 3, 3 ... caused by the secondary flows Y-1, Y-2 as in the first embodiment, the refrigerant has an outer periphery of the spiral flow path 125. It is largely cooled by the side and the cooling effect is enhanced.
Therefore, the condenser 1 can be miniaturized.
The cross section of the spiral channel 125 is not limited to a square. The cross section of the spiral channel 125 may be trapezoidal, pentagonal, hexagonal or the like.

Fifth Embodiment
The fifth embodiment will be described with reference to FIG. For the sake of convenience of explanation, the same parts as those of the first embodiment are denoted by the same reference numerals, and the explanation thereof is omitted. In the fifth embodiment, only the configurations of the two tubes 2-1 and 2-2 on the inlet side of the condenser (heat dissipation device) 1 are different from those of the first embodiment. Since the two tubes 2-1 and 2-2 have the same configuration, the tube 2-1 will be described, and the description of the tube 2-2 will be omitted.

FIG. 9A shows a tube 2-1.
The vortex flow forming body 51 is connected to the inlet of the tube 2-1, and the flow straightening body 71 is fitted on the downstream side of the vortex flow forming body 51. The vortex flow forming body 51 is fitted to the inner peripheral portion of the tube 2-1 as shown in FIG. 10A. The vortex flow forming body 51 is closed on the downstream side in a dome shape in a state of being disposed on one end side of the in-tube flow passage 12, and has a bag-nut shape and has an inflow portion 52 inside. The outer peripheral wall of the inflow portion 52 has a large diameter portion 53 and a small diameter portion 54. The large diameter portion 53 is fitted to the inner peripheral portion of the tube 2-1, and a gap δ is formed between the outer peripheral portion of the small diameter portion 54 and the inner peripheral portion of the tube 2-1. In the small diameter portion 54, six through holes 55 are formed as shown in FIG. 10B. The through hole 55 extends in the tangential direction of the inner peripheral wall 56 of the inflow portion 52 and communicates the inflow portion 52 with the in-tube flow passage 12.

The refrigerant entering the vortex flow forming body 51 flows into the inflow portion 52, and from the six through holes 55 provided in the small diameter portion 54, as shown by the arrow R (FIG. 10A), to the inner peripheral portion of the tube 2-1. To flow. The medium that has flowed into the inner peripheral portion of the tube 2-1 spirally flows from the upstream side toward the downstream side on the inner periphery of the tube 2-1, and a large spiral refrigerant on the downstream side of the vortex flow forming body 51 Form an eddy current UX. The refrigerant that has become the spiral vortex UX flows spirally along the inner wall surface of the tube 2-1, and the heat of the refrigerant is dissipated from the outer wall surface of the tube 2-1.

As shown in FIG. 9B, the straightening body 71 is formed by forming a plurality of linear grooves 72 in the outer peripheral portion of a solid round bar and forming a through passage 73 in the central portion. The refrigerant generates an eddy current UX until the inner periphery of the tube 2-1 reaches the rectifying body 71, and flows spirally toward the downstream side, and when reaching the rectifying body 71, a plurality of linear grooves 72 and penetrations It flows into the path 73 where it is rectified. Since the central portion of the flow is at a low temperature, a through passage 73 is provided.

When flowing in the form of a spiral vortex UX, the refrigerant is on the side closer to the inner wall surface of the tube 2-1 and on the side closer to the center of the in-tube flow passage 12 (FIG. 9A) It turned out that it separated and flowed. It was found that the refrigerant flowed at high speed on the side close to the inner wall surface of the tube 2-1, resulting in a large vortex flow UX. That is, since the refrigerant flows at high speed along the inner wall surface of the tube 2-1, a centrifugal force acts on the refrigerant to cause a temperature separation phenomenon, and the inner wall surface side of the tube 2-1 becomes hot and the flow center The part side becomes low temperature.
In the fifth embodiment, since the vortex flow forming body 51 is provided in the tube 2-1 and the rectifying body 71 is provided on the downstream side of the vortex flow forming body 51, the refrigerant is between the vortex flow forming body 51 and the flow rectifying body 71. And heat flows from the outer wall surface of the tube 2-1 efficiently because it flows separately to the side closer to the inner wall surface of the tube 2-1 and the side closer to the center of the in-tube flow path 12 (FIG. 9A). The heat can be dissipated, and the heat dissipation effect can be improved. The same action and effect are exhibited in the tube 2-2.

The refrigerant having passed through the two tubes 2-1 and 2-2 passes through the evaporator 1 through the remaining tubes 2-3 to 2-6. The heat radiation effect of the tubes 2-3 to 2-6 is the same as that of the first embodiment, and thus the description thereof is omitted.

In the above embodiments, the case where the refrigerant flows through the tubes 2-1 to 2-6 of the heat dissipation device 1 has been described, but the present invention is not limited to this, and a gas, a gas-liquid two-phase fluid, Alternatively, it is suitable for flowing a fluid such as water through the tubes 2-1 to 2-6 and dissipating the heat of the gas, the gas-liquid two-phase fluid, or the fluid such as water to the outside.
Therefore, it is particularly suitable for a heat dissipating device such as a car radiator, an oil cooler, an intercooler, a condenser of a car air conditioner, an evaporator and the like.
In the present invention, since the cross sections of the

spiral flow channels

25 and 125 are polygonal, the heat dissipation effect can be enhanced, so that the heat dissipation device can be miniaturized.

In the above embodiment, the

radiation fins

3, 3, 3... Are provided on the outer peripheral side of the

spiral flow passages

25 and 125 as the radiation portions, but the present invention is not limited to the radiation fins 3.
For example, a cooling pipe (not shown) may be disposed on the outer peripheral side of the

spiral flow channels

25 and 125, and a water cooling type heat dissipating unit may be configured by a medium such as water flowing through the cooling pipe.
Although the present invention has been described above based on the embodiments, the present invention is not limited to these embodiments. In the above embodiment, all the tubes are provided with the core, but the present invention is not limited to all.

DESCRIPTION OF SYMBOLS 1 Condenser 2-1-2-6

Tube

3, 3, 3 ... Heat dissipation fin 21 Core 23 Groove part 25 Spiral flow path 51 Vortex flow formation body 71 Rectification body 121 Polygonal tube 125 Spiral flow path

Claims

What is claimed is: 1. A heat dissipation device comprising: a polygonal tube wound in a spiral form to form a spiral flow passage having a polygonal cross section; and a heat dissipation portion provided on an outer peripheral side of the spiral flow passage.
A core is fitted on at least the inlet side of the tube, and a spiral groove is provided on the outer periphery of the core, and a spiral flow passage having a polygonal cross section between the groove and the inner wall of the tube is provided. A heat dissipation device comprising a heat dissipation portion on an outer peripheral side of a path.
The heat sink according to claim 2, wherein a pitch of the grooves is formed to be gradually narrowed toward the downstream.
The spiral flow channel generates a primary flow along the length direction of the flow channel and a secondary flow rotating in the cross section of the flow channel, and the cross section of the spiral flow channel generates a plurality of secondary flows The heat dissipation device according to any one of claims 1 to 3, which is in a form.
The heat dissipation device according to any one of claims 1 to 4, wherein the heat dissipation portion is configured by a heat dissipation fin.
A radiator, an oil cooler, an intercooler, a radiator of any one of a condenser of a refrigeration cycle and an evaporator, comprising the radiator according to any one of claims 1 to 5.
A refrigeration cycle comprising a compressor, a condenser, a decompression device, and an evaporator, wherein the condenser comprises the heat dissipation device according to any one of claims 1 to 5.