KR20200092177A - Water based phase change material heat exchanger - Google Patents

Abstract

A water-based phase change material heat exchanger according to various embodiments includes: an insulating housing filled with a water-based phase change material; a heat transfer pipe that penetrates the inside of the insulating housing and is surrounded by the water-based phase change material; a first elastic member surrounding the water-based phase change material on the inner wall of the insulating housing; and a second elastic member disposed inside the heat transfer pipe to support the heat transfer pipe while passing a fluid flowing inside the heat transfer pipe.

Description

WATER BASED PHASE CHANGE MATERIAL HEAT EXCHANGER}

Various embodiments relate to water based phase change material heat exchangers.

In general, a phase change material heat exchanger (PCM heat exchanger) is a kind of heat management device that accumulates latent heat using a phase change material and provides a constant temperature heat source when necessary. In the heat exchanger, heat can enter and exit the fluid from the phase change material. It may be desirable for the phase change material in the heat exchanger to remain phase-independent. However, it may be practically impossible for the phase of the phase change material to remain constant. For example, the phase of the phase change material may be changed at the start or end of the operation of the heat exchanger, and the phase of the phase change material may be partially or entirely changed during operation of the heat exchanger.

However, when water is used as a phase change material in the heat exchanger as described above, the phase change of the phase change material may cause structural defects of the heat exchanger. This is because water can increase in volume as it freezes. In particular, when reverse icicles are generated due to an internal stress relationship due to volume expansion, stress may be partially concentrated and serious damage may occur in the heat exchanger.

A water-based phase change material heat exchanger according to various embodiments includes an insulating housing filled with a water-based phase change material, a heat transfer pipe penetrating the interior of the heat insulation housing and surrounded by the phase change material, and the heat insulation The inner wall of the housing may include an elastic member surrounding the phase change material.

A water-based phase change material heat exchanger according to various embodiments, an insulating housing filled with a water-based phase change material, a heat transfer pipe penetrating the interior of the heat insulation housing and surrounded by the water-based phase change material, and It may be disposed inside the heat transfer pipe, and passing through a fluid flowing inside the heat transfer pipe, and may include an elastic member supporting the heat transfer pipe.

According to various embodiments, a water-based phase change material heat exchanger may absorb stress generated during a phase change of a water-based phase change material by using an elastic member. At this time, the elastic member may absorb the stress, corresponding to at least one of the heat insulating housing or the heat transfer pipe. Through this, at least one of the insulating housing or the heat transfer pipe can be protected from stress through the elastic member. Accordingly, in the water-based phase change material heat exchanger, damage due to the phase change of the water-based phase change material can be prevented.

1 is a graph for explaining a general phase change.
2A and 2B are cross-sectional views showing a typical heat exchanger.
3 is a perspective view showing a water-based phase change material heat exchanger according to various embodiments.
4 is a cross-sectional views showing a water-based phase change material heat exchanger according to the first embodiment.
5 is a cross-sectional views showing a water-based phase change material heat exchanger according to a second embodiment.
6 and 7 are exemplary views showing the elastic member of FIG. 5.
8 is a cross-sectional views showing a water-based phase change material heat exchanger according to a third embodiment.
9 is a cross-sectional view for describing the characteristics of the elastic members of FIG. 8.

Hereinafter, various embodiments of the present document will be described with reference to the accompanying drawings.

It should be understood that the various embodiments of the document and the terms used therein are not intended to limit the technology described in this document to specific embodiments, and include various modifications, equivalents, and/or substitutes of the embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar elements. Singular expressions may include plural expressions unless the context clearly indicates otherwise. In this document, expressions such as "A or B", "at least one of A and/or B", "A, B or C" or "at least one of A, B and/or C", etc. are all of the items listed together. Possible combinations may be included. Expressions such as "first", "second", "first" or "second" can modify the corresponding components, regardless of order or importance, and are used only to distinguish one component from other components The components are not limited. When it is stated that one (eg, first) component is “connected (functionally or communicatively)” to another (eg, second) component or is “connected,” the component is the other It may be directly connected to the component, or may be connected through another component (eg, the third component).

Molecular arrangements that depend on thermal energy under a certain pressure can affect the macroscopic behavior of the material. The phase change of the material is caused by the entry and exit of heat, and phase changes between the solid phase, liquid phase, and gas phase can be commonly observed.

1 is a graph for explaining a general phase change. 1 shows the phase change of ice-water at 1 atmosphere.

Referring to FIG. 1, when heat is applied to sub-zero ice, the temperature of ice may increase according to specific heat. When the ice temperature reaches 0 degrees, the heat is continuously absorbed by the ice, but there is a section where the ice temperature does not change. At this time, the heat that changes the temperature may be referred to as sensible heat, and the heat that does not change the temperature may be referred to as latent heat. Latent heat does not change the temperature of the ice and can be used for phase change.

The presence of latent heat can provide a variety of industrial applications. This is because using latent heat, a heat source having a constant temperature can be obtained. For this reason, latent heat is used in automobiles, aerospace, high-tech weapons, electronic measuring and communication devices, nuclear fusion, storage/carrying of biochemicals, physical therapy medical devices, and thermal storage batteries using late-night electricity. Practically, phase changes can occur in any material. However, for convenience, a material having high industrial utilization will be referred to as a “Phase change material (PCM)”.

2A and 2B are cross-sectional views showing a typical heat exchanger.

2A and 2B, general heat exchangers 210 and 220 can manage heat. The general heat exchanger 210, by using the fan 211, as shown in Figure 2a, by forcing convection in the air around the heat transfer pipe 213 through which the fluid flows, it is possible to enter and exit the heat. On the other hand, the general phase change material heat exchanger 220, as shown in Figure 2b, the heat flowing between the fluid flowing in the heat transfer pipe 223 and the general phase change material 225 surrounding the heat transfer pipe 223. You can go in and out. That is, the phase change material heat exchanger 220 may be a kind of heat management device that accumulates latent heat using the phase change material 225 and provides a constant temperature heat source when necessary. In the phase change material heat exchanger 200, it may be desirable for the phase change material 225 to remain unchanged. However, it may be practically impossible for the phase of the phase change material 225 to remain constant. For example, the phase of the phase change material may change when the phase change material heat exchanger 220 starts or ends, and the phase of the phase change material may change partially or entirely during operation of the phase change material heat exchanger 220. Can. However, the phase change of the phase change material may not affect the phase change material heat exchanger 220. This may be because a typical phase change material has a reduced volume upon condensation.

According to various embodiments, a water based phase change material heat exchanger can be provided. Since water can increase in volume as it freezes, water-based phase change materials can cause structural defects in the phase change material heat exchanger as described above. However, water is cheap, and the latent heat and density are 1.7 times and 1.3 times higher than paraffin wax, which is a common phase change material. Based on this, considering the characteristics of the heat exchanger according to the phase change material determined as shown in [Equation 1], the size and weight of the water-based phase change material heat exchanger and the general phase change material heat exchanger are 40% and 54, respectively. There can be as much as% difference.

At this time, the phase change material heat exchanger may be mounted on an automobile, a spacecraft, or the like. Due to this, the weight of the phase change material heat exchanger must be minimized. That is, the phase change material heat exchanger should be light and free from mechanical defects even in repeated ice and thaw. Here, since the thermal conductivity of the phase change material is relatively lower than that of the metal, it may be desirable to increase the effective thermal conductivity using the metal. For example, since the metal foam (or foam metal) has a large specific surface area, it can be applied to heat transfer of the phase change material. The porosity of the metal foam can be as high as 0.9 or more and this property can be very desirable for reducing the weight of the phase change material heat exchanger. The metal foam may be made of, for example, aluminum, copper, or nickel. However, a metal foam, for example, a metal foam made of aluminum reacts elastically to a deformation of about 4% to 6%, but there may be a problem that the structure is not restored to further deformation. Therefore, considering that the temporary volume change is 9% when the phase changes from the solid phase of the water to the liquid phase, the metal foam may not be suitable for a water-based phase change material heat exchanger.

3 is a perspective view showing a water-based phase change material heat exchanger according to various embodiments.

Referring to FIG. 3, the water-based phase change material heat exchanger 300 according to various embodiments may include an insulating housing 310, a heat transfer pipe 330, and at least one elastic member (not shown). .

The insulating housing 310 may be filled with a water-based phase change material (not shown). At this time, the insulating housing 310 may store a water-based phase change material therein.

The heat transfer pipe 330 may penetrate the interior of the insulating housing 310. Here, both ends of the heat transfer pipe 330 may be exposed to the outside of the insulating housing 310. At this time, inside the heat transfer pipe 330, a fluid may flow. Here, the fluid may be drawn through one end of the heat transfer pipe 330, and the fluid may be drawn out through the other end of the heat transfer pipe 330. And the heat transfer pipe 330 may be surrounded by a water-based phase change material. This allows heat to enter and exit between the fluid and the phase change material.

The elastic member may be provided to prevent mechanical damage to the water-based phase change material heat exchanger 300. At this time, the elastic member can prevent the mechanical damage of the water-based phase change material heat exchanger 300 when the phase change of the water-based phase change material. To this end, the elastic member may be mounted to at least one of the heat insulating housing 310 or the heat transfer pipe 330. Here, the elastic member may have elasticity based on at least one of a material or a structure. For example, the elastic member may have an elastic limit exceeding at least 9%. Through this, the elastic member can absorb the stress generated during the phase change of the water-based phase change material.

4 is a cross-sectional views showing a water-based phase change material heat exchanger according to the first embodiment. At this time, Figure 4 (a) shows a side cross-section of the water-based phase change material heat exchanger according to the first embodiment, Figure 4 (b) is a water-based phase change material heat exchanger according to the first embodiment A cross section cut along A-A' of FIG.

Referring to FIG. 4, the water-based phase change material heat exchanger according to the first embodiment (eg, the water-based phase change material heat exchanger 300 of FIG. 3) 400 is an insulated housing (eg, an insulation housing of FIG. 3) (310)) 410, may include a heat transfer pipe (eg, the heat transfer pipe 330 of FIG. 3) 430 and the elastic member 450.

The insulating housing 410 may be filled with a water-based phase change material 420. At this time, the insulating housing 410 may store a water-based phase change material therein.

The heat transfer pipe 430 may penetrate the interior of the insulating housing 410. Here, both ends of the heat transfer pipe 430 may be exposed to the outside of the insulating housing 410. At this time, in the interior of the heat transfer pipe 430, fluid may flow. Here, the fluid may be drawn through one end of the heat transfer pipe 430, and the fluid may be drawn out through the other end of the heat transfer pipe 430. In addition, the heat transfer pipe 430 may be surrounded by a water-based phase change material 420. Through this, heat may enter and exit between the fluid and the phase change material 420. For example, the heat transfer pipe 430 may include a fin (not shown). For example, 휜 is formed on the outer wall of the heat transfer pipe 430, by expanding the contact area of the water-based phase change material 420 and the heat transfer pipe 430, the heat transfer surface of the heat transfer pipe 430 Can be expanded.

The elastic member 450 may be disposed between the insulating housing 410 and the water-based phase change material 420. To this end, the elastic member 450 may be mounted on the inner wall of the insulating housing 410. Through this, the elastic member 450 may surround the water-based phase change material 420. In other words, the elastic member 450 may center the heat transfer pipe 430 and encapsulate the water-based phase change material 420. Here, the elastic member 450 may have elasticity based on at least one of a material or a structure. For example, the elastic member 450 may have an elastic limit exceeding at least 9%. In addition, the elastic member 450 may absorb stress generated when the phase of the water-based phase change material 420 changes. That is, the elastic member 450 may block transmission of stress from the water-based phase change material 420 to the insulating housing 410. Accordingly, the elastic member 450 can prevent damage to the insulating housing 410.

5 is a cross-sectional views showing a water-based phase change material heat exchanger according to a second embodiment. 5(a) shows a side cross-section of a water-based phase change material heat exchanger according to the second embodiment, and FIG. 5(b) shows a water-based phase change material heat exchanger according to the second embodiment. A cross-section cut along B-B' of FIG. And FIGS. 6 and 7 are exemplary views showing the elastic member of FIG. 5.

Referring to FIG. 5, the water-based phase change material heat exchanger (eg, the water-based phase change material heat exchanger 300 of FIG. 3) 500 according to the second embodiment is an insulating housing (eg, an insulation housing of FIG. 3) (310)) 510, may include a heat transfer pipe (eg, the heat transfer pipe 330 of FIG. 3) 530 and the elastic member 550.

The insulating housing 510 may be filled with a water-based phase change material 520. At this time, the insulating housing 510 may store a water-based phase change material therein.

The heat transfer pipe 530 may penetrate the interior of the insulating housing 510. Here, both ends of the heat transfer pipe 530 may be exposed to the outside of the insulating housing 510. At this time, inside the heat transfer pipe 530, fluid may flow. Here, the fluid may be drawn through one end of the heat transfer pipe 530, and the fluid may be drawn out through the other end of the heat transfer pipe 530. And the heat transfer pipe 530 may be surrounded by a water-based phase change material 520. Through this, heat may enter and exit between the fluid and the phase change material 520. For example, the heat transfer pipe 530 may include a fin (not shown). For example, 휜 is formed on the outer wall of the heat transfer pipe 530, by extending the contact area of the water-based phase change material 520 and the heat transfer pipe 530, the heat transfer surface of the heat transfer pipe 530 Can be expanded.

The elastic member 550 may be disposed inside the heat transfer pipe 530. At this time, the elastic member 550 may support the heat transfer pipe 530 while passing a fluid flowing inside the heat transfer pipe 530. Here, the elastic member 550 may have elasticity based on at least one of a material or a structure. For example, the elastic member 550 may have an elastic limit exceeding at least 9%. And the elastic member 550 can absorb the stress generated when the phase change of the water-based phase change material 520. That is, the elastic member 550 can absorb the stress transferred from the water-based phase change material 520 to the heat transfer pipe 530. Accordingly, the elastic member 550 can prevent the heat transfer pipe 530 from being damaged. In addition, the elastic member 550 may be formed of metal. Here, the elastic member 550 may be formed of a metal having high thermal conductivity. The elastic member 550 may be formed of, for example, aluminum, copper, or nickel. Through this, the elastic member 550 may expand the heat transfer surface of the heat transfer pipe 530 by expanding the contact surface between the heat transfer pipe 530 and the fluid.

For example, the elastic member 550 may have a shape in which a plurality of elastic cells 600 are combined in a cell structure. Here, each of the elastic cells 600 may be formed to have a high porosity based on the shape of the polyhedron as shown in FIG. 6(a). In addition, each elastic cell 600 may include a plurality of micro springs 610 mounted on each side of the polyhedron as shown in FIG. 6B. For example, the micro springs 610 may form corners of a polyhedron. As the elastic cells 600 are combined into a cell structure, the elastic cells 600 may be arranged as shown in FIG. 6C. For example, the elastic member 550 may be formed based on 3D printing technology as shown in FIG. 7.

8 is a cross-sectional views showing a water-based phase change material heat exchanger according to a third embodiment. At this time, Figure 8 (a) shows a side cross-section of the water-based phase change material heat exchanger according to the third embodiment, Figure 8 (b) is a water-based phase change material heat exchanger according to the third embodiment C-C' of the cross section. And Figure 9 is a cross-sectional view for explaining the properties of the elastic members of FIG.

Referring to FIG. 8, the water-based phase change material heat exchanger (eg, the water-based phase change material heat exchanger 300 of FIG. 3) 800 according to the third embodiment is an insulating housing (eg, an insulating housing of FIG. 3) (310) (810), heat transfer pipe (e.g., the heat transfer pipe 330 of FIG. 3) 830, the first elastic member (e.g., the elastic member 450 of FIG. 4) 851 and the second An elastic member (eg, the elastic member 550 of FIG. 5) 853 may be included.

The insulating housing 810 may be filled with a water-based phase change material 820. At this time, the insulating housing 810 may store a water-based phase change material therein.

The heat transfer pipe 830 may penetrate the interior of the insulating housing 810. Here, both ends of the heat transfer pipe 830 may be exposed to the outside of the insulating housing 810. At this time, inside the heat transfer pipe 830, a fluid may flow. Here, the fluid may be drawn through one end of the heat transfer pipe 830, and the fluid may be drawn out through the other end of the heat transfer pipe 830. In addition, the heat transfer pipe 830 may be surrounded by a water-based phase change material 820. Through this, heat may enter and exit between the fluid and the phase change material 820. For example, the heat transfer pipe 830 may include a fin (not shown). For example, 휜 is formed on the outer wall of the heat transfer pipe 830, by expanding the contact area of the water-based phase change material 820 and the heat transfer pipe 830, the heat transfer surface of the heat transfer pipe 830 Can be expanded.

The first elastic member 851 may be disposed between the insulating housing 810 and the water-based phase change material 820. To this end, the first elastic member 851 may be mounted on the inner wall of the insulating housing 810. Through this, the first elastic member 851 may surround the water-based phase change material 820. In other words, the first elastic member 851 may center the heat transfer pipe 830 and encapsulate the water-based phase change material 820. Here, the first elastic member 851 may have elasticity based on at least one of a material or a structure. For example, the first elastic member 851 may have an elastic limit exceeding at least 9%. In addition, the first elastic member 851 can absorb stress generated when the phase of the water-based phase change material 820 changes. That is, the first elastic member 851 may block transmission of stress from the water-based phase change material 820 to the insulating housing 810. Accordingly, the first elastic member 851 can prevent damage to the insulating housing 810.

The second elastic member 853 may be disposed inside the heat transfer pipe 830. At this time, the second elastic member 853 may support the heat transfer pipe 830 while passing a fluid flowing inside the heat transfer pipe 830. Here, the second elastic member 853 may have elasticity based on at least one of a material or a structure. For example, the second elastic member 853 may have an elastic limit exceeding at least 9%. And the second elastic member 853 can absorb the stress generated when the phase change of the water-based phase change material 820. That is, the second elastic member 853 can absorb the stress transferred from the water-based phase change material 820 to the heat transfer pipe 830. Accordingly, the second elastic member 853 can prevent damage to the heat transfer pipe 830. In addition, the second elastic member 853 may be formed of metal. Here, the second elastic member 853 may be formed of a metal having high thermal conductivity. The second elastic member 853 may be formed of, for example, aluminum, copper, nickel, or the like. For example, the second elastic member 853 may have a shape in which a plurality of elastic cells (eg, the elastic cells 600 of FIG. 6) are combined in a cell structure as illustrated in FIG. 6 or 7. . Through this, the second elastic member 853 may expand the heat transfer surface of the heat transfer pipe 830 by expanding the contact surface between the heat transfer pipe 830 and the fluid.

According to the third embodiment, the water-based phase change material 820 may be in a steady state between the heat insulating pipe 830 and the heat insulating housing 810, as shown in Figure 9 (a). And as shown in Figure 9 (b), as the water-based phase change material 820 is condensed, stress may be generated from the water-based phase change material 820. At this time, the first elastic member 851 and the second elastic member 853 can absorb stress. That is, the first elastic member 851 blocks the transfer of stress from the water-based phase change material 820 to the insulating housing 810, and the second elastic member 853 transfers heat from the water-based phase change material 820 The stress transmitted to the pipe 830 can be absorbed. Accordingly, damage to the insulating housing 810 and the heat transfer pipe 830 may be prevented. Thereafter, as shown in FIG. 9C, as the water-based phase change material 820 melts, stress may be removed from the water-based phase change material 820.

According to various embodiments, the water-based phase change material heat exchanger (300, 400, 500, 800) using the elastic member (450, 550, 851, 853), the water-based phase change material (420, 520, 820) ) Can absorb the stress generated when the phase changes. At this time, the elastic member (450, 550, 851, 853) corresponding to at least one of the heat insulating housing (310, 410, 510, 810) or heat transfer pipes (330, 430, 530, 830), to absorb the stress Can. Through this, at least one of the insulating housings 310, 410, 510, 810 or the heat transfer pipes 330, 430, 530, 830 can be protected from stress through the elastic members 450, 550, 851, 853. have. Accordingly, in the water-based phase change material heat exchanger (300, 400, 500, 800), damage due to the phase change of the water-based phase change material (420, 520, 820) can be prevented.

Although various embodiments of the present document have been described, various modifications are possible without departing from the scope of the various embodiments of the present document. Therefore, the scope of various embodiments of the present document should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by the scope and equivalents of the claims.

Claims (10)

In the water based phase change material heat exchanger,
An insulating housing filled with a water-based phase change material;
A heat transfer pipe passing through the interior of the insulating housing and surrounded by the phase change material; And
A heat exchanger including a first elastic member surrounding the phase change material on the inner wall of the insulating housing.
According to claim 1,
The heat exchanger is disposed inside the heat transfer pipe, and further includes a second elastic member supporting the heat transfer pipe while passing a fluid flowing inside the heat transfer pipe.
The method of claim 2, wherein the second elastic member,
It has a structure in which a plurality of elastic cells having the shape of a polyhedron are combined,
A heat exchanger comprising a plurality of micro springs mounted on each side of the polyhedron.
The method of claim 3, wherein the micro springs,
A heat exchanger forming the edges of the polyhedron.
The method of claim 2, wherein the second elastic member,
Heat exchanger formed of metal.
In the water based phase change material heat exchanger,
An insulating housing filled with a water-based phase change material;
A heat transfer pipe passing through the interior of the insulating housing and surrounded by the phase change material; And
The heat exchanger is disposed inside the heat transfer pipe and includes an elastic member supporting the heat transfer pipe while passing a fluid flowing inside the heat transfer pipe.
According to claim 1, The elastic member,
It has a structure in which a plurality of elastic cells having the shape of a polyhedron are combined,
A heat exchanger comprising a plurality of micro springs mounted on each side of the polyhedron.
The method of claim 7, wherein the micro springs,
A heat exchanger forming the edge of the polyhedron.
The method of claim 6, wherein the elastic member,
Heat exchanger formed of metal.
The method of claim 6,
A heat exchanger further comprising another elastic member surrounding the phase change material on the inner wall of the insulating housing.

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