JPH11132685A - Heat exchanging body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the thermal resistance of air layer from causing a trouble in heat exchange by forming a porous body in a tubular body integrally therewith. SOLUTION: This heat exchanging body 1a comprising a porous body 5a formed in a tubular body 3a integrally therewith is applied tightly to a Peltier element at the time of use. The heat exchanging body 1a is cast by lost wax process. Since the heat exchanging body 1a is integrated with the porous body 5a in the tubular body, no air layer is present between the porous body and the inner surface of the tubular body and thereby thermal resistance due to the air layer can be eliminated. The heat exchanging body has a significantly high heat exchanging capacity and it can be used with no trouble even when the temperature difference of heat exchange is small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger, for example, a heat exchanger closely contacting a Peltier element. In the present specification including the claims, the term "Peltier element" refers to a thermoelectric element that generates and absorbs heat using the Peltier effect.

[0002]

2. Description of the Related Art The following are already known as such heat exchangers. (A) A heat exchanger formed by projecting a large number of fins such as aluminum. (B) A heat exchanger having a porous body disposed in an aluminum pipe.

[0003]

However, the conventional heat exchanger has the following problems.

(A) A heat exchanger formed by projecting a large number of fins made of aluminum or the like. The heat exchange capacity is low because the surface area per unit volume for heat exchange is small. If a large number of fins are protruded at a small pitch, the surface area per unit volume can be increased, but on the other hand, the workability is reduced and the air flow between the fins is deteriorated, and the heat exchange property is reduced. The problem arises.

(B) A heat exchanger formed by arranging a porous body in an aluminum pipe The porous body has a large surface area per unit volume. High heat exchange capacity. However, since the porous body is not integrated with the aluminum pipe, there is a slight layer of air between the porous body and the inner surface of the aluminum pipe. This layer of air becomes heat resistance and hinders heat exchange. This thermal resistance is not so problematic when the difference in the temperature at which the heat exchange is performed is large, but in a heat exchanger that is closely attached to the Peltier element, the difference in the temperature at which the heat exchange is performed is small, so the thermal resistance due to the air layer Is an obstacle to heat exchange.

The present invention has been made to solve the above-mentioned problems concerning the heat exchanger by improving the heat exchanger in which a porous body is disposed in the aluminum pipe described in (b) above. is there.

[0007]

Means for Solving the Problems In order to solve the above problems, the present invention provides the following heat exchanger.

(1) A heat exchanger, wherein a porous body is formed in a cylindrical body in a state where the porous body is integrated with the cylindrical body.

(2) A heat exchanger which is used in close contact with a Peltier element, characterized in that a porous body is formed in a tubular body in a state of being integrated with the tubular body. (Claim 2). The term “close contact” between the heat exchanger and the Peltier device in the present specification including the claims includes not only the case where the heat exchanger and the Peltier device are directly contacted, but also the case where the heat exchanger and the Peltier device are used. For example, the case where the contact is made through an intervening substance such as silicon oil or grease is also included.

(3) The heat exchanger is desirably cast by a lost wax method.

[0011]

[Function] Originally, a porous body in a cylindrical body has a high heat exchange capacity because of a large surface area per unit volume.
In the heat exchanger according to the present invention, since the porous body in the tubular body is integrated with the tubular body, no air layer is formed between the porous body and the inner surface of the tubular body. In other words, there is no thermal resistance due to such a layer of air. Therefore, the heat exchanger according to the present invention has an extremely high heat exchange capacity.

[0012]

Next, embodiments of the present invention will be described with reference to the accompanying drawings. The heat exchanger 1 according to the present invention is formed by forming a porous body 5 in a tubular body 3 in a state of being integrated with the tubular body 3. The cylindrical body 3 and the porous body 5 are integrally formed of a metal having high thermal conductivity such as aluminum and copper. The cross section of the cylindrical body 3 is not limited, such as a cylindrical body or a rectangular cylindrical body. The porous body 5 is formed in a sponge shape as an example, and the shape, surface area, volume, etc. of the porous body 5 can be arbitrarily selected according to the use, etc., together with the shape, volume, length, etc. of the tubular body 3. it can.

The heat exchanger 1a shown in FIG. 1 is formed by integrating a porous body 5a with a cylindrical body 3a in a cylindrical body 3a. FIG. 2 shows an enlarged part of the heat exchanger 1a.

The heat exchanger 1b shown in FIG. 3 is formed by forming a porous body 5b in a rectangular tubular body 3b in a state of being integrated with the tubular body 3b.

FIG. 4 shows an example in which the heat exchanger 1 of the present invention is used in an air dehumidifier. The reference numeral 7 indicates a Peltier element. The power supply of the Peltier element 7 is DC5V · 2A in the illustrated case. Heat exchangers 1A and 1B are brought into close contact with the cooling side 7a and the heating side 7b of the Peltier element 7, respectively. Silicon oil is interposed between the Peltier element 7 and the heat exchangers 1A and 1B in order to prevent the presence of an air layer between the Peltier element 7 and the heat exchangers 1A and 1B. Reference numerals 9 and 11 denote inlets and outlets in the heat exchanger 1A on the cooling side.
Reference numeral 15 denotes an inlet and an outlet of the heat exchanger 1B on the heating side. The outlet 11 of the cooling-side heat exchanger 1A communicates with the inlet of the dehumidifier 19 via the connecting pipe 17, and the outlet of the dehumidifier 19 connects via the connecting pipe 21 to the heating-side heat exchanger 1B.
Is communicated with the entrance 13 at. Reference numeral 23 denotes an inlet pipe attached to the inlet 9 of the heat exchanger 1A on the cooling side, and reference numeral 25 denotes an outlet pipe attached to the outlet 15 of the heat exchanger 1B on the heating side.

In the case shown in FIG. 4, the air to be treated enters the inlet 9 of the heat exchanger 1A on the cooling side through the inlet pipe 23. Since the cooling-side heat exchanger 1A is cooled by the cooling side 7a of the Peltier element 7, the cooling-side heat exchanger 1A
The air that has entered is cooled to a temperature below the dew point and becomes supersaturated, producing water droplets. The porous body 5 formed in the heat exchanger 1A on the cooling side not only promotes heat exchange, but also functions to repeatedly adhere small water droplets and grow them. The air thus cooled is introduced into the dehumidifier 19 through the connecting pipe 17 together with water droplets. Dehumidifier 19
The water droplets are separated from the air inside and discharged from the drain outlet. The air from which the water droplets have been removed exits the dehumidifier 19 in a saturated state, and is introduced into the heating-side heat exchanger 1B via the connecting pipe 21. The heat exchange body 1B on the heating side is heated by the heating side 7b of the Peltier element 7, and further includes a porous body 5 for promoting heat exchange therein. Therefore, the air introduced into the heat exchanger 1B on the heating side is heated and increases in volume, and the relative humidity decreases. In this manner, the air is dehumidified and exits through the outlet pipe 25 from the outlet 15 of the heat exchanger 1B.

[0017]

5 to 9 show a specific example of a heat exchanger 1 according to the present invention. The heat exchanger 1c is formed by forming a porous body 5c in a substantially cylindrical tubular body 3c in an integrated state with the tubular body 3c. Substantially cylindrical tubular body 3
c and the porous body 5c are integrally formed of aluminum. The heat exchanger 1c has a substantially square edge 31 at both ends.
The edge 31 has a through hole 33 for attachment. The heat exchanger 1c has an insertion hole 35 for a fixing tool such as a bolt on the side of the cylindrical body 3c. The dimensions of the illustrated heat exchanger 1c are as follows. Inner diameter: 16mm Outer diameter: 20mm Length: 100mm Volume of porous body 5c: about 19 cubic cm

The heat exchanger 1c is cast by a lost wax method. An example of a method for manufacturing the heat exchanger 1c will be described below with reference to FIGS.

(1) Mold production (FIG. 10) A mold 41 for forming a wax mold corresponding to the heat exchanger 1c.
To produce That is, after examining the mold structure, creating a mold drawing, the mold 41 is manufactured by machining.

(2) Formation of wax mold (FIG. 11) Using the mold 41 manufactured, a hollow wax mold 43 'is molded by an injection molding machine, and a sponge-like body of wax is inserted into the hollow wax mold 43'. Thus, a wax pattern 43 corresponding to the heat exchanger 1c is formed.

(3) Tree assembly (FIG. 12) The wax mold 43 is assembled into a tree 45 based on a casting method. It is assumed that the tree 45 includes four wax patterns 43 as an example.

(4) Injection of gypsum (FIG. 13) The assembled tree 45 is put in a flask 47, a plaster 49 is injected into the flask 47, and the plaster 49 is solidified.

(5) Dewaxing and firing (FIG. 14) The casting flask 47 is removed, the solidified gypsum 49 is placed in a furnace 51, and the gypsum 49 is heated to about 100 ° C. with steam to remove wax from the gypsum. Melt out. By melting the wax from the gypsum 49, a space 53 corresponding to the tree 45 is formed in the gypsum 49. This plaster 49 is about 600
The mold 55 is formed by heating at a high temperature of ° C. and firing.

(6) Casting (FIG. 15) The molten aluminum 57 at about 720 ° C. is injected into the space 53 in the mold 55.

(7) Dispersion and cutting of the mold (FIG. 16) The mold 55 is broken and the aluminum casting 59 is taken out.
Cut off the gate and the hot water.

(8) Grinding / Finishing (FIG. 17) The casting 59 is ground and finished by the grinding device 65.

(9) Processing / Alumite (FIG. 18) The casting 59 is machined to form an oxide film on the surface, thereby forming the porous body 5c in the substantially cylindrical body 3c. Heat exchanger 1 formed in a state integrated with
c is obtained.

Next, a test performed when the heat exchanger was used in the air dehumidifier shown in FIG. 4 will be described.

[Test 1] Difference between the temperature of the inlet 9 and the temperature of the outlet 11 in the heat exchanger on the cooling side when using the following heat exchanger in the air dehumidifier shown in FIG. 4 (cooling temperature). The heat exchange performance of each of the following heat exchangers was evaluated by measuring the difference (heating temperature) between the temperature of the inlet 13 and the temperature of the outlet 15 in the heat exchanger on the heating side. Example 1: Heat exchanger 1c of the above example (porous body volume about 19 cubic cm) Comparative example 1: Aluminum cylindrical body filled with copper fiber (volume about 19 cubic cm) as porous body Comparative example 2: cylindrical body made of aluminum (without porous body)
The dimensions of the heat exchanger of Example 1, Comparative Example 1, and Comparative Example 2 are as follows. Inner diameter: 16 mm Outer diameter: 20 mm Length: 100 mm The air flow rate is 120 liters / minute. Table 1 shows the results of this test.

[0030]

[Table 1]

As is clear from Table 1, the difference between the temperature of the inlet 9 and the temperature of the outlet 11 in the heat exchanger on the cooling side and the difference between the temperature of the inlet 13 and the temperature of the outlet 15 in the heat exchanger on the heating side. In any case, not only the heat exchanger of Example 1 showed a larger value than the heat exchanger of Comparative Example 2, but also
The value was larger than that of the heat exchanger of Comparative Example 1. In other words, the heat exchanger of Example 1 not only has better heat exchange performance than the heat exchanger of Comparative Example 2, but also has better heat exchange performance than the heat exchanger of Comparative Example 1. It has been found.

[Test 2] Another test performed when the heat exchanger of Example 1 (the volume of the porous body was about 19 cubic cm) was used in the air dehumidifier shown in FIG. 4 will be described. The flow rate of air was 120 liter / min, and the input power was 8W.

When the temperature of the inlet 9 of the heat exchanger on the cooling side is 17.7 ° C., the outlet 11 of the heat exchanger on the cooling side
Was 13.7 ° C. (cooling temperature). Converting this change into electric power results in 9.5 W. At this time,
Temperature at the outlet 15 of the heat exchanger on the heating side (heating temperature)
Was 19.1 ° C. The amount of change is 12.8 W when converted into electric power. That is, the COP value is 1.18.

On the other hand, an aluminum cylindrical body (with an inner diameter of 1)
The same measurement was performed on a heat exchanger (Comparative Example 3) in which copper fibers (volume: about 44 cubic cm) were filled as a porous body in a 6 mm, outer diameter of 20 mm, and a length of 100 mm. Was 1.2.

That is, the heat exchanger of Example 1 (the volume of the porous body was about 19 cubic cm) was the same as the heat exchanger of Comparative Example 3 (the volume of the porous body was about 44 cubic cm). Despite being about ２, CO 2 is almost the same as the heat exchanger of Comparative Example 3.
P values could be achieved. From this point, too, the first embodiment
It can be seen that the heat exchange efficiency of the heat exchanger is high.

[Test 3] Furthermore, when the heat exchanger of Example 1 (the volume of the porous body was about 19 cubic cm) was used for the air dehumidifier shown in FIG. Tables 2 and 3 show the results of measurements performed on the inlet 9 of the heat exchanger).

[0037]

[Table 2]

[0038]

[Table 3]

As is clear from Tables 2 and 3, Example 1
Showed favorable COP values for various inlet temperatures (temperature at inlet 9 in the heat exchanger on the cooling side).

[0040]

In the heat exchanger according to the present invention, since the porous body in the tubular body is integrated with the tubular body, an air layer is formed between the porous body and the inner surface of the tubular body. There is nothing you can do. In other words, there is no thermal resistance due to such a layer of air. Therefore, the heat exchanger according to the present invention has an extremely high heat exchange capacity, and can be used without any trouble even when the difference in the temperature at which heat is exchanged is small. That is, the heat exchanger according to the present invention does not cause any problem even when used in close contact with the Peltier element.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a heat exchanger according to the present invention.

FIG. 2 is a reference view showing a part of the same heat exchanger in an enlarged manner.

FIG. 3 is a perspective view showing another example of the heat exchanger according to the present invention.

FIG. 4 is an explanatory diagram showing an example in which the heat exchanger of the present invention is used in an air dehumidifier.

FIG. 5 is a plan view showing still another example of the heat exchanger according to the present invention.

FIG. 6 is a front view of the same heat exchanger.

FIG. 7 is a side view of the heat exchanger.

8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a cross-sectional view along IX-IX in FIG. 6;

FIG. 10 is an explanatory view showing the manufacture of a mold in the manufacturing process of the heat exchanger.

FIG. 11 is an explanatory view showing a wax mold in a manufacturing process of the heat exchanger.

FIG. 12 is an explanatory diagram showing tree assembly in a heat exchanger manufacturing process.

FIG. 13 is an explanatory diagram showing gypsum injection in a manufacturing process of the heat exchanger.

FIG. 14 is an explanatory diagram showing dewaxing and firing in the manufacturing process of the heat exchanger.

FIG. 15 is an explanatory view showing pouring in a manufacturing process of the heat exchanger.

FIG. 16 is an explanatory diagram showing mold dispersion and cutting in the manufacturing process of the heat exchanger.

FIG. 17 is an explanatory diagram showing grinding and finishing in a manufacturing process of the heat exchanger.

FIG. 18 is an explanatory view showing processing in a manufacturing process of the heat exchanger.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchanger 1a Heat exchanger 1b Heat exchanger 1c Heat exchanger 1A Heat exchanger 1B Heat exchanger 3 Cylindrical body 3a Cylindrical body 3b Cylindrical body 3c Cylindrical body 5 Porous body 5a Porous body 5b Porous Body 5c Porous body 7 Peltier element 7a Cooling side 7b Heating side 9 Inlet 11 Outlet 13 Inlet 15 Outlet 17 Connecting pipe 19 Dehumidifier 21 Connecting pipe 23 Inlet pipe 25 Outlet pipe 31 Edge 33 Through hole 35 Insertion hole 41 Mold 43 Wax mold 43 'Hollow wax mold 45 Tree 47 Casting frame 49 Plaster 51 Furnace 53 Space 55 Mold 57 Aluminum 59 Casting 65 Grinding device

Claims (3)

[Claims] 1. A heat exchanger, wherein a porous body is formed in a cylindrical body in a state where the porous body is integrated with the cylindrical body. 2. A heat exchanger which is used in close contact with a Peltier element, characterized in that a porous body is formed in a cylindrical body in a state of being integrated with the cylindrical body. Heat exchanger. 3. The heat exchanger according to claim 1, wherein the heat exchanger is cast by a lost wax method.