JPH01300194A - Heat exchanger - Google Patents

Abstract

PURPOSE:To prevent the increase of pressure loss due to the installation of an air discharging passage in an inlet tank by a method wherein the sectional configuration of a connecting part between the inlet tank including the air discharging passage and an inlet pipe is changed smoothly. CONSTITUTION:The sectional configuration of an inlet tank 3 from the connecting part of an inlet pipe 8 to a radiator cap 11 is so constituted that the sectional area S1 (shown by slant lines) of a connecting part between the inlet tank 3 including an air discharging passage 14 and the inlet pipe 8 is reduced along a predetermined length L by the reduction of the sectional area of the air discharging passage 14 and, thereafter, another sectional area S2 (shown by slant lines) is continued to the position of the radiator cap 11. The configuration of the connecting part of the inlet pipe 8 of the air discharging passage 14 is configured so that the sectional area per unit length is reduced gradually with a rate less than 5.5mm<2>d/mmd. According to this method, the sectional configuration of the connecting part between the inlet tank 3 including the air discharging passage 14 and the inlet pipe 8 is changed smoothly and slowly whereby the increase of a flow water resistance at this part may be restrained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an inlet tank and an outlet tank above and below a core portion formed by a plurality of tubes arranged in parallel to form fluid passages for heat exchange. Regarding heat exchangers.

[Prior Art] In recent years, in order to improve the fuel efficiency of vehicles, there has been a demand to reduce the weight of each in-vehicle component. One idea is to reduce the volume of engine cooling water that flows into the inlet tank.

However, when the inlet tank is made smaller to reduce the volume of engine cooling water flowing into the radiator (the height of the inlet tank is lowered), the top of the inner surface of the inlet tank is lower than the top of the inner surface of the inlet pipe. As a result, the air flowing into the inlet tank together with the engine cooling water from the inlet pipe flows into the tubes forming the core portion together with the engine cooling water, reducing the heat dissipation efficiency of the radiator.

Therefore, in order to solve these problems,
In Publication No. 50240, as shown in FIGS. 8 and 9, an air exhaust passage 102 is added to the inlet tank 101, which is formed to have a lower height and a smaller internal capacity.
A technique for forming a is disclosed.

In addition, Figure 8 is a front view of the radiator inlet tank, Figure 9 is a front view of the radiator inlet tank,
The figure shows a sectional view of the inlet tank including the passage for air evacuation.

This air discharge passage 102 extends from the water inlet 103 provided in the center of the inlet tank 101 to the inlet pipe 104 provided near the end of the inlet tank 101, and is approximately equivalent to the top of the inner surface of the inlet pipe 104. The top side of the inlet tank 101 is formed to protrude to a height of , or higher.

As a result, the air that has flowed into the inlet tank 101 together with the engine cooling water from the inlet pipe 104 passes through the air exhaust passage 102 and reaches the water inlet 103.
3 and is discharged to the outside of the radiator 100 through the discharge pipe 105.

As a result, the volume of engine cooling water flowing into the inlet tank 101 can be reduced without reducing the heat dissipation effect of the radiator 100, and therefore the weight of the radiator 100 can be reduced.

[Problems to be Solved by the Invention] However, in the prior art described in the above-mentioned publication, by forming the air discharge passage 102 in the inlet tank 101, the air discharge from the inlet pipe 104 to the inlet tank 101 is reduced compared to the conventional technology. The problem is that the change in the cross-sectional shape becomes large, and therefore the pressure loss increases during this time.

The present invention has been made in view of the above circumstances.The purpose of the present invention is to
It is an object of the present invention to provide a heat exchanger which prevents an increase in pressure loss due to the formation of an air discharge passage on the top side of an inlet tank.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a core portion formed by a plurality of tubes arranged in parallel to form fluid passages for heat exchange, and an inlet pipe into which fluid flows, an inlet tank provided in an upper part of the core part in communication with the tube; an outlet pipe from which a fluid flows out; an outlet tank provided in a lower part of the core part in communication with the tube; and the inlet tank. and an air discharge section provided at the top of the inlet tank for discharging air mixed into the inlet tank from the inlet pipe, and the inlet tank discharges the air mixed into the inlet tank from the inlet pipe. In order to lead to the discharge part,
An air exhaust passage formed so as to protrude from the top side of the inlet tank extends from the inlet pipe to the air exhaust part, and the air exhaust passage extends from the connection part with the inlet pipe to the air exhaust part. over a predetermined length toward
The technical means is to have a region whose cross-sectional area per unit length gradually decreases at a rate of 5.5-7 m or less.

[Operations and Effects of the Invention] The present invention having the above-mentioned configuration is provided with an air exhaust passage formed in the inlet tank such that the top side of the inlet tank protrudes, and this air exhaust passage is connected to the inlet pipe. It was formed so that the cross-sectional area per unit length gradually decreased over a predetermined length from the section toward the air discharge section at a rate of 5.5-71 m or less.

As a result, the cross-sectional shape of the connection part of the inlet tank with the inlet pipe, including the air discharge passage, changes gradually, making it possible to prevent an increase in flow resistance when the fluid to be heat exchanged flows into the inlet tank. Therefore, it is possible to prevent an increase in pressure loss caused by providing an air discharge passage in the inlet tank.

[Example] Next, a heat exchanger of the present invention applied to a vehicle radiator will be described based on an example shown in the drawings.

FIG. 1 shows a perspective view of a radiator which is a heat exchanger of the present invention.

The radiator 1 of this embodiment includes a core part 2 that cools each part of the engine and cools the heated cooling water by exchanging heat with surrounding air, an inlet tank 3 provided on the upper part of the core part 2, and the core part. 2 and an outlet tank 4 provided at the bottom of the tank.

The core part 2 is a state in which tubes 5, which are heat exchange passages through which cooling water passes, and corrugated fins 6, which improve the heat dissipation characteristics of the radiator 1, are stacked horizontally as shown in FIG. The upper end of each tube 5 is provided in communication with the inlet tank 3, and the lower end is provided in communication with the outlet tank 4.

The tube 5 is formed of a thin plate of lightweight metal with good heat conductivity, such as brass or aluminum, so that its cross section has a flat oval shape.

The corrugated fin 6 is made by bending a thin aluminum plate into a corrugated shape, and has a large number of notches (not shown) formed on its surface in order to improve the heat dissipation effect of the radiator 1.

The inlet tank 3 and the outlet tank 4 are made of lightweight and corrosion-resistant resin (for example, nylon resin containing glass fiber as a reinforcing material), and are connected to an engine overjacket (not shown) by a cooling water pipe 7. There is.

Near one end in the longitudinal direction of the inlet tank 3 (first
An inlet pipe 8 is provided near the left side of the figure, to which the above-mentioned cooling water pipe 7 is connected, and for allowing the cooling water pumped from the overjacket to flow into the inlet tank 3. A replenishment port 9 for injecting cooling water into the radiator 1 is provided at the top.

Near the other end in the longitudinal direction of the outlet tank 4 (first
On the right side of the figure), an outlet bypass 110 is provided for discharging the cooling water that has passed through each tube 5 of the core section 2 and collected in the outlet tank 4 from the outlet tank 4. The above-mentioned cooling water pipe 7 is connected to this outlet pipe 10, and the cooling water flowing out from the outlet pipe 10 is fed under pressure to the overjacket.

A radiator cap 11 incorporating a pressure valve and a negative pressure valve (both not shown) is removably attached to the above-mentioned supply port 9.

The radiator cap 11 has a preset pressure in the cooling water path (for example, a gauge pressure of 09 kg/cd).
), the pressurizing valve opens and the cooling water in the radiator 1 is discharged to the reserve tank 13 via the overflow pipe 12 attached to the radiator cap 11, and the temperature of the cooling water path decreases, causing cooling. When the pressure of the water path becomes lower than the atmospheric pressure, the negative pressure valve opens and sucks the cooling water in the reserve tank 13 to replenish the water.

Further, this radiator cap 11 functions as an air discharge section of the present invention for discharging air mixed into the inlet tank 3 together with the cooling water.

In order to reduce the weight of the radiator 1, the above-mentioned inlet tank 3 is formed so that the height H of the inlet tank 3 is lowered to reduce its internal capacity, and the inlet tank 3 is mixed into the inlet tank 3 through the inlet pipe 8. Remove the air from the radiator cap 1
1, from the inlet pipe 8 to the radiator cap 1.
An air exhaust passage 14 is provided extending over the entire length of the inlet tank 3 and protruding from the top side of the inlet tank 3.

This air discharge passage 14 is determined based on experimental results so that the shape of its connecting portion is optimal in order to suppress an increase in pressure loss caused by forming the air discharge passage 14 in the inlet tank 3.

Note that FIG. 6 is a graph showing changes in pressure loss with respect to changes in shape of the connecting portion between the air discharge passage 14 and the inlet tank 3.

In this graph, the air exhaust passage 14 is connected to the inlet pipe 8.
over a predetermined length I from the connection part with the radiator cap 11, the cross-sectional area per unit length is 5.5.
-/++s or less, the pressure drop does not increase compared to the case of a radiator having a conventional inlet tank that does not form the air exhaust passage 14. ing.

Therefore, in order to satisfy the values based on the experimental results, in this embodiment, the air discharge passage 14 is extended for a predetermined length from the connection point with the inlet pipe 8 as shown in FIG. The width of the air exhaust passage 14 is formed so as to decrease at the rate of the taper angle of 30 degrees. In this embodiment, the taper angle is 30 degrees, but the taper angle may be less than 30 degrees. .

FIG. 2 is a plan view of the connection portion of the inlet tank 3 including the air discharge passage 14 with the inlet pipe 8, and FIG. 3 is a side view of FIG. 2.

Therefore, the cross-sectional shape of the inlet tank 3 from the connection part with the inlet pipe 8 to the radiator cap 11 is as shown in FIG. After the cross-sectional area of the air exhaust passage 14 decreases over a predetermined length from the cross-sectional area S1 (the shaded area), the cross-sectional area S2 (the shaded area) decreases to the radiator cap 11, as shown in FIG. range).

Note that FIG. 4 shows the inlet tank 3 including the air discharge passage 14.
FIG. 5 is a sectional view of the connection part with the inlet pipe 8 of the air exhaust passage 1 after the cross-sectional area has been reduced over a predetermined length l.
FIG.

As mentioned above, the shape of the connecting portion of the air discharge passage 14 with the inlet pipe 8 is such that the cross-sectional area per unit length is 5.5.
By forming the structure so that it gradually decreases at a rate of less than -/min, the cross-sectional shape of the connection part between the inlet tank 3 and the inlet pipe 8, including the air discharge passage 14, changes gradually, and water flow in this part It is possible to suppress the increase in resistance. Therefore, an increase in pressure loss caused by providing the air discharge passage 14 in the inlet tank 3 can be prevented.

Furthermore, since the cross-sectional shape of the connecting portion between the inlet tank 3 and the inlet pipe 8 changes gradually, it is possible to prevent cracks from occurring due to stress concentration.

FIG. 7 shows a second embodiment of the present invention.

In the first embodiment, the width of the air exhaust passage 14 is formed to decrease at a rate of 30 degrees over a predetermined length, but the unit length of the air exhaust passage 14 is If the range in which the cross-sectional area per unit area gradually decreases at a rate of 5.5 mJ/m or less is satisfied, the connection portion between the air exhaust passage 14 and the inlet pipe 8 is connected in a curved manner, as shown in FIG. It's okay.

Note that FIG. 7 shows the inlet tank 3 including the air discharge passage 14.
FIG. 3 is a plan view of the connection portion with the inlet pipe 8 of FIG.

(Modified example) In the above-described embodiment, the heat exchanger of the present invention was applied as a radiator for a vehicle, but it is not necessary to limit it to a radiator, and it is also possible to apply it to a heat exchanger of a hot water heating device.

The core part is not limited to the structure of a tube and corrugated fins, and plate fins or the like may be used instead of the corrugated fins.

[Brief explanation of the drawing]

1 to 6 show a first embodiment of the present invention.
The figure is a perspective view of the radiator, the second figure is a plan view of the connection part with the inlet pipe of the inlet tank including the air exhaust passage, and the third figure is a perspective view of the radiator.
The figure is a side view of Figure 2, Figure 4 is a sectional view of the connection part with the inlet pipe of the inlet tank including the air exhaust passage, and Figure 5 is the view after the cross-sectional area has been reduced over a predetermined length. 6 is a graph showing the relationship between the gradually decreasing cross-sectional area ratio and pressure loss; FIG. 7 shows a second embodiment of the present invention; FIGS. 8 and 9 are a plan view of the connecting portion of the inlet tank including the passageway to the inlet pipe, and FIG. 9 shows the prior art; FIG. 8 is a front view of the inlet tank;
FIG. 9 shows a sectional view of the inlet tank including the air discharge passage. In the diagram: 1...Radiator (heat exchanger) 2...Core part 3...Inlet tank 4...Outlet tank 5.
...Tube 8...Inlet pipe 10...Outlet pipe 11...Radiator cap (air discharge part) 1
4... Air exhaust passage

Claims (1)

[Claims] 1) A core portion including a plurality of tubes arranged side by side to form fluid passages for heat exchange, and an inlet pipe into which fluid flows, and a core portion communicating with the tubes at the upper part of the core portion. an inlet tank provided at the top of the inlet tank, an outlet tank provided at the bottom of the core portion and in communication with the tube, the outlet tank including an outlet pipe through which fluid flows out; and an air discharge part for discharging air mixed in the tank, and the inlet tank guides the air mixed in the inlet tank from the inlet pipe to the air discharge part, so that the air is discharged from the inlet pipe. An air exhaust passage formed to project from the top side of the inlet tank is provided across the exhaust part, and the air exhaust passage has a predetermined length toward the air exhaust part from the connection part with the inlet pipe. A heat exchanger characterized by having a region in which the cross-sectional area per unit length gradually decreases at a rate of 5.5 mm^2/mm or less.