JPH08313178A - Evaporator for heat exchanger - Google Patents

Abstract

PURPOSE: To obtain a higher heat exchanging performance 10 a small heat exchanger by arranging a liquid return port below a porous plate with a liquid return pipe piercing the porous plate while a steam port is arranged above the porous plate. CONSTITUTION: A porous plate 10 is arranged at a position above the liquid level of a fluid 6 for heat exchange inside an evaporator 1 for a heat exchanger. A liquid return port 3a is arranged below the porous plate 10 and a steam port 2a is arranged above the porous plate 10. A liquid return area 7 is secured at a bottom surface part of the evaporator 1 to receive the fluid 6 for heat exchange and a distribution area 8 following the area 7. A number of ridges 5 having a clearance therebetween are arranged in another area and a number of grooves comprising clearances are made to communicate with the distribution area 8. This enables obtaining of higher heat exchanging performance even in a small heat exchanger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporator of a heat exchanger in which heat is exchanged by evaporating and condensing a heat exchange fluid, and more particularly to cooling electric parts such as thyristors and power transistors. The present invention relates to a small-sized evaporator for a heat exchanger suitable for.

[0002]

2. Description of the Related Art Electric parts such as thyristors and power transistors are used by incorporating them in a predetermined circuit. However, since they generate a large amount of heat and the required performance cannot be obtained or deteriorates, the heat exchanger is used. The cooling was done.
By the way, these electric parts are often installed on a substrate on which various parts are integrated in order to miniaturize electric products, and naturally the heat exchanger is also required to be small and space-saving. Therefore, means for devising the shape of the heat exchanger is also taken, for example, by making the evaporator to be brought into contact with a heating element such as a thyristor into a flat shape and reducing the dimension in the height direction, It is designed to be compact and avoid interference with other parts.

The heat exchanger 20 will be described in detail with reference to FIG. 6. A heat generating element 22 (member to be cooled) such as a thyristor is closely attached to the outer lower surface of an evaporator 21 having a flat shape. , This evaporator 21 has a condenser 23
Are connected via a vapor pipe 24 and a liquid return pipe 25.
One end of the vapor pipe 24 is opened at the upper surface of the evaporator 21 and is provided with a vapor port 24a, while the liquid return pipe 25 is provided in the evaporator 2.
1 penetrates the upper surface, the tip is located in the evaporator 21, and the tip is opened and a liquid return port 25a is provided. A liquefied or vaporized heat exchange fluid 26 is provided between the evaporator 21, the steam pipe 24, the condenser 23, and the liquid return pipe 25.
Circulates with heat exchange.

[0004]

However, the above-mentioned evaporator 21 has the following problems due to its flat shape. First, the height inside the evaporator 21 is low,
Since the liquid surface of the heat exchange fluid 26 and the steam port 24a are close to each other, the splashes generated during boiling of the heat exchange fluid 26 adhere to the steam port 24a and the inner surface of the steam pipe 24 to cause the outflow of steam or the like. There is a problem that the heat exchange performance is remarkably deteriorated by hindering the movement to reduce the flow rate of the vapor, and further, the splashes are scattered to the condenser 23 to cover the inner surface of the condenser 23 and prevent the liquefaction of the vapor. . Second, since the height of the evaporator 21 is low, the depth of the heat exchange fluid contained in the interior is shallow and the circulation of the fluid is poor, so that the heat of the fluid becomes non-uniform and good heat exchange is achieved. There is a problem that it is not done. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an evaporator that can obtain good heat exchange performance even in a small heat exchanger.

[0005]

In order to solve the above-mentioned problems, the first aspect of the present invention is a heat exchanger evaporator for storing and evaporating a liquefied heat exchange fluid in a heat exchanger evaporator. A perforated plate that covers the liquid surface is disposed above the liquid surface of the heat exchange fluid that has been pooled, and a liquid return pipe penetrates the perforated plate and the liquid return port is located below the perforated plate. Is arranged, and the steam port is arranged above the perforated plate.

In the heat exchanger evaporator of the second invention, a liquid return region for receiving a heat exchange fluid returning from the liquid return port is provided on the bottom face part of the evaporator, and the fluid is continuous with the liquid return region to the bottom face part. A distribution area for distribution to other areas is secured, and on the bottom surface of the other area, a large number of protrusions are arranged in parallel with each other with a gap, and a large number of grooves formed by the gaps are formed. It is characterized in that it communicates with the distribution area.

The porous plate in the first aspect of the invention preferably covers the entire liquid surface as much as possible. Further, the liquid surface should not contact the perforated plate and contact the lower surface of the perforated plate or have a predetermined gap.From this viewpoint, the perforated plate is installed at an appropriate position between the liquid surface and the vapor port. It Further, it is desirable that the holes formed on the plate surface of the perforated plate allow the vapor to smoothly flow upward and prevent splashes from passing through as much as possible. From these viewpoints, the size, number and arrangement of the holes are appropriately selected. For example, the size of the holes is preferably 2 to 15 mm, and the opening ratio of the holes (area ratio with respect to the whole perforated plate) is preferably 20 to 50%. Further, the shape of the hole is not particularly limited, and may be a polygonal shape such as a circle or a quadrangle. Further, a plurality of perforated plates may be arranged at intervals in the upper and lower sides. In that case, in order to prevent the passage of splashes more effectively, it is preferable to dispose the holes in the upper and lower perforated plates so that their positions are shifted. desirable.

According to the second aspect of the invention, the position, shape, width, etc. of the liquid return region and the distribution region are appropriately determined according to the shape of the evaporator and the position, shape, etc. of the liquid return pipe, and the space for these regions is defined. Secure. Also, when liquid return is performed over a wide range with multiple liquid return pipes or flat liquid return pipes, the liquid return area and the distribution area may be the same area, or part of the distribution area may also be used as the liquid return area. It is also possible to let. It is desirable that the bottom surface of the evaporator located at the bottom of the liquid return region and the distribution region is a smooth surface so that the movement of the liquid is not impaired. It is possible to provide a ridge.

Further, the number, gaps, and arrangement of the protrusions provided in the other regions are not particularly limited, but the heat exchange fluid liquefied by the grooves formed by the gaps spreads uniformly in all directions of the evaporator. It is desirable to set to, for example, a ridge can be provided so as to extend along the entire length of the other region in the longitudinal direction. When the ridge is below the liquid surface, the upper end thereof is preferably as close as possible to the liquid surface, and more preferably has a height exceeding the liquid surface.

In addition, it is possible to secure an alternating current region in which a ridge is not provided in a part of the other region except the liquid return region and the distribution region, which promotes the alternating current of the liquid and makes the heat of the liquid uniform. The property is improved. This AC region communicates with the above-mentioned groove, but in addition to communicating with the groove at the end on the side different from the side communicating with the distribution region, it is provided between the groove and the groove on both sides. You may make it connect. When provided between the grooves in this way, the groove on one side of the AC region is
It will communicate indirectly with the distribution area through the AC area. The first invention and the second invention can be combined, and in this case, the perforated plate can be installed by placing the perforated plate on the protrusion in the second invention. The evaporator of the present invention is suitable for a small heat exchanger used for cooling exothermic electric parts and the like as described above, but the present invention is not particularly limited in its application and is small. It is not limited to.

[0011]

That is, according to the first aspect of the present invention,
The droplets generated by the boiling of the heat exchange fluid are prevented from rising by the perforated plate, and then fall onto the liquid surface. Even if some of the droplets pass through the hole, the momentum is lost due to the passage of the hole, and the splash to the steam port and steam pipe is blocked, and eventually the liquid drops from the hole to the liquid surface below. To fall. The heat exchange fluid that has boiled into steam in the evaporator quickly passes through the holes of the perforated plate and rises without being hindered from moving by the droplets, and then smoothly flows from the steam port located above the perforated plate. Spill to. This heat exchange fluid reaches the condenser through, for example, a steam pipe, where good heat exchange is performed and it is liquefied. The liquefied heat exchange fluid passes through the liquid return pipe, passes through the perforated plate, and is stored again in the evaporator through the liquid return port. At this time, the porous plate does not hinder the liquid return. As described above, the heat exchange fluid smoothly moves in the heat exchanger including the evaporator, accompanied by evaporation and condensation, and excellent heat exchange is performed, resulting in excellent heat exchange in the entire heat exchanger. Performance is obtained.

Next, according to the second aspect of the invention, the liquefied heat exchange fluid is returned to the liquid return region and flows into the continuous distribution region. These liquid return and distribution areas are
It only occupies a part of the bottom of the evaporator, and the heat exchange fluid is evenly distributed in this region to make the heat uniform. A large number of grooves are in communication with the distribution area, and the homogenized fluid does not remain in the distribution area but is substantially evenly distributed to the large number of grooves and flows into the other areas through the grooves. Further, if the AC region is secured, the heat exchange fluid once flowing into the groove is mixed in the AC region, and depending on the arrangement of the grooves, the heat exchange fluid is dispersed and flows into a larger number of grooves. By the movement of these liquids, the returned liquid for heat exchange is uniformly dispersed and mixed at the bottom of the evaporator, and the liquid is made uniform throughout the bottom of the evaporator. Therefore, heat is uniformly exchanged on the entire bottom surface of the evaporator, and heat exchange efficiency is improved.

The ridges dramatically increase the contact area between the heat exchange fluid and the evaporator, and further improve the heat exchange performance. In addition, this ridge promotes the generation of minute boiling nuclei of the heat exchange fluid, and prevents the generation of coarse bubbles due to boiling to further improve the heat exchange performance. It is also possible to combine the second invention and the first invention. According to this combination, in addition to the effects of the first and second inventions, the droplets are liable to be generated relatively upward by the protrusion. However, it is possible to effectively prevent scattering to the steam port or the like due to the action of the perforated plate.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The evaporator 1 made of an aluminum alloy has a flat and closed box shape, a steam pipe 2 is connected to one end of the upper surface thereof, and a liquid return pipe 3 is connected to the center of the upper surface thereof. And the other end of the liquid return pipe 3 is a condenser 4
Are connected to the lower sides of both sides. In the condenser 4, a condenser (not shown) is provided between the vapor pipe 2 and the liquid return pipe 3, and the vapor pipe 2 communicates with the condenser and the liquid return pipe 3. A radiator fin (not shown) is provided on the outer surface of the condenser 4.

On the inner bottom surface of the evaporator 1 described above, except for the central zone and both end zones based on the horizontal longitudinal direction,
A large number of ridges 5 ... 5 having predetermined gaps are arranged in parallel along the longitudinal direction, and the grooves 5 are formed by the respective gaps.
a is configured. The ridges 5 ... 5 correspond to the evaporator 1
The liquefied heat exchange fluid 6 accommodated therein has a height protruding beyond the liquid surface. In this embodiment, the protrusions 5 ... 5 are arranged side by side by using an extruded mold material having a large number of protrusions 5 ... 5 integrally formed on a flat plate as the bottom plate of the evaporator 1. The central zone on the bottom surface of the evaporator 1 is composed of a diamond-shaped central area having a wide area and narrow strip-shaped portions located on both sides thereof, and the central area is assigned to the liquid return region 7. And the strips are assigned to the distribution area 8. Further, the both end bands correspond to the alternating current region 9.

Next, a perforated plate 10 covering the entire surface of the heat exchange fluid 6 in the evaporator 1 is placed and fixed on the projections 5 ... 5, and the perforated plate 10 has a large number of plates. Hole 10a ... 10a
Are formed at equal intervals, and the diameter of the holes 10a is 9 mm.
The total aperture ratio is 2 with respect to the total area of the porous plate 10.
It is set to be 5%. The porous plate 1
The liquid return pipe 3 penetrates from the upper part in the center of 0, and the liquid return port 3a formed at the tip of the liquid return pipe 3 is below the perforated plate 10 and above the liquid return region 7. positioned. The tip of the vapor pipe 2 is located on the upper surface of the evaporator 1, and the vapor port 2a is formed at the tip.

Next, the operation of the heat exchanger using the evaporator will be described. Inside the evaporator 1, the liquefied heat exchange fluid 6 is contained, and the liquid level thereof is at a position lower than the upper ends of the protrusions 5 described above at the maximum. On the lower surface of the evaporator 1, a heating element 1 to be a member to be cooled is formed.
1, 11 are attached, and the heat of the heating element 11 is
The heat exchange fluid 6 is passed through the bottom plate of the evaporator 1 and the ridges 5.
Is transmitted to The heat exchange fluid 6 boils and evaporates due to this heat, and the vapor thereof passes through the holes 10a of the perforated plate 10 and flows out from the vapor port 2a. The splashes generated during this boiling are effectively blocked by the perforated plate 10, and the steam flows out smoothly. The steam flows through the steam pipe 2 into the condensation section of the condenser 4, where it is heat-exchanged and liquefied. The liquefied heat exchange fluid is collected in the liquid return pipe 3, flows down in the pipe, and is finally returned from the liquid return port 3a to the liquid return region 7.

The heat exchange fluid returned to the liquid return area 7 is
It spreads from the liquid return area 7 to the distribution area 8 where it is mixed with the heat exchange fluid already contained. Further, the heat exchange fluid 6 flows from the distribution area 8 into the large number of grooves 5a, is uniformly diffused along the grooves 5a to the entire bottom of the evaporator 1, and the liquid is made uniform. Further, the heat exchange fluid 6 diffusing in the groove 5a finally reaches the AC region 9 and is mixed with the heat exchange fluid diffusing in the other groove 5a in this region, and further homogenization is promoted. . As described above, in the evaporator 1, the uniformization of the liquid is constantly performed, the heat exchange is efficiently performed, and the heat exchange fluid is boiled and evaporated by the heat transfer from the heating element 11. Further, during the boiling, the ridges 5 prevent the generation of coarse bubbles and the deterioration of the heat exchange performance.

In the above embodiment, the first invention and the second invention of the present invention have been described in combination, however, in the present invention, naturally, either one may be adopted alone. Also, the effect of improving the heat exchange performance can be obtained. Further, in the above-mentioned embodiment, the AC region is provided on both sides of the evaporator 1. However, the AC region can be omitted in the present invention, and as shown in FIG. 4, the AC region is provided between the grooves. It is also possible to secure twelve. Further, although the number of the perforated plate is one in the above-mentioned embodiment, the perforated plate 1 shown in FIG.
You may use two or more perforated plates like 3 and 14.
In the embodiment of FIG. 5, the holes 13a of the perforated plate 13 and the holes 14a of the perforated plate 14 are horizontally displaced to more effectively prevent the passage of droplets.

Next, in order to confirm the effect of improving the heat exchange performance of the present invention, a performance test was conducted. In this test, the heat exchanger of the above embodiment (test No. 1, first invention + second invention)
And a heat exchanger in which the ridges are omitted and only the perforated plate is provided (Test N
o. 2, first invention), a heat exchanger without a perforated plate (Test No. 3, second invention), and a conventional heat exchanger without a perforated plate and ridges (Test No. 4, conventional example). In place of the heating element, a dummy heat source is attached to the bottom surface of the evaporator through a plurality of heat conductors, and the contact temperature with the dummy heat source in the evaporator and the influence of heat from the dummy heat source are used. The heat exchange performance was evaluated by measuring the temperature difference (ΔT) from the ambient temperature. The results are as follows. Test No. ΔT (° C.) No. 1 55 No. 2 62 No. 3 73.2 No. 4 76.1 As is apparent from the above, any heat exchanger using the evaporator of the embodiment of the present invention is conventional. It was shown that the dummy heat source was cooled well and the above-mentioned temperature difference was small as compared with the example, and that it had excellent cooling performance. Therefore,
It was confirmed that the heat exchange performance was significantly improved by adopting the present invention.

[0021]

As described above, the first aspect of the present invention
According to the heat exchanger evaporator of the invention of the invention, a porous plate for covering the liquid surface is arranged at a position above the liquid surface of the heat exchange fluid stored in the evaporator for the heat exchanger, The liquid return pipe is pierced through this and the liquid return port is arranged below the perforated plate,
Moreover, since the steam port is arranged above the perforated plate, it is possible to eliminate the adverse effect of the droplets generated due to the boiling of the heat exchange fluid, prevent the deterioration of the heat exchange performance, and provide a heat exchanger with excellent heat exchange performance. Obtainable.

Further, according to the evaporator for a heat exchanger of the second invention, a liquid return region for receiving the heat exchange fluid returning from the liquid return port is provided on the bottom face of the evaporator, and the fluid is continuous with the liquid return region. Securing a distribution area for distributing the other area of the bottom part,
On the bottom surface of the other area, a large number of ridges having gaps are arranged in parallel, and a large number of grooves formed by the gaps are communicated with the distribution area, so that the heat exchange fluid is made uniform in the evaporator. Good heat exchange. Moreover, the heat transfer area is greatly increased by the protrusions, and the heat exchange performance is further improved.

[Brief description of drawings]

FIG. 1 is a front view in which a part of a heat exchanger to which an embodiment of the present invention is applied is sectioned.

FIG. 2 is likewise a side view with a partial cross section.

FIG. 3 is likewise a plan sectional view of an evaporator in which a perforated plate is omitted.

FIG. 4 is a plan sectional view of an evaporator of another embodiment in which a perforated plate is omitted.

FIG. 5 is a side sectional view showing an evaporator of still another embodiment.

FIG. 6 is a partially sectional front view showing a conventional heat exchanger.

[Explanation of symbols]

 1 Evaporator 2 Steam Pipe 2a Steam Port 3 Liquid Return Pipe 3a Liquid Return Port 4 Condenser 5 Projection 5a Groove 6 Heat Exchange Fluid 7 Liquid Return Area 8 Distribution Area 9 AC Area 10 Perforated Plate 10a Hole 11 Heating Element 12 AC Region 13 Perforated Plate 13a Hole 14 Perforated Plate 14a Hole

Claims (2)

[Claims] 1. An evaporator for a heat exchanger for storing and evaporating a liquefied heat exchange fluid, wherein the liquid level is provided inside the evaporator and above the liquid level of the stored heat exchange fluid. Characterized in that a perforated plate that covers the perforated plate is disposed, a liquid return pipe penetrates the perforated plate, a liquid return port is disposed below the perforated plate, and a vapor port is disposed above the perforated plate. Evaporator for heat exchanger 2. An evaporator bottom surface is provided with a liquid return region for receiving a heat exchange fluid returning from a liquid return port, and a distribution region continuous with the liquid return region for distributing the fluid to another region of the bottom surface portion. It is ensured that, on the bottom surface of the other area, a large number of ridges are arranged in parallel with each other with a gap, and a large number of grooves formed by the gap communicate with the distribution area. Characteristic evaporator for heat exchanger