HK1075086B - Total heat exchanging element - Google Patents

Description

Total heat exchange element

Technical Field

The present invention relates to a heat exchange element having a laminated structure used in a heat exchange device for exchanging heat between two fluids, which is applied to the field of air conditioning, and more particularly to a total heat exchange element for exchanging both latent heat and sensible heat.

Background

A total heat exchange element having a laminated structure, which has been generally used in the air conditioning field, is formed by laminating and bonding basic structural members, each of which is formed by laminating a planar-shaped partition member and a sectional wave-shaped space holding member, so that the wave directions of the space holding members are orthogonal to each other or intersect at an angle close thereto. In the passages adjacent in the stacking direction formed by the space holding members of the total heat exchange element, sensible heat and latent heat are exchanged between the two fluids by flowing air flows in different states (usually, different air in a temperature and humidity state) through the dividing members as media.

Since the partition member exists between the 2 air flows and exists as a medium for sensible heat and latent heat exchange, the heat transfer property and moisture permeability of the partition member have a great influence on sensible heat and latent heat exchange power as a total heat exchange element. The space holding member holds the space between the partition members and has a function of securing 2 gas flow passages.

In addition, in the total heat exchange element for air conditioning, it is necessary to reduce carbon dioxide (C0) particularly between 2 streams₂) And so on, and therefore, in addition to the above-described performance, high gas shielding properties are required for both the dividing member and the space holding member.

Further, from the viewpoint of ensuring safety as a product, the total heat exchange element itself is also required to have high flame retardancy. Since the partition member and the space holding member of the total heat exchange element need various performances, various partition members and space holding members are used.

In order to find out the above-described functions, the following examples are known as conventional total heat exchange elements (see, for example, patent document 1): a base paper produced by mixing a moisture absorbing/releasing powder and a hot-melt adhesive substance into a pulp mainly composed of papermaking fibers is subjected to a treatment of impregnating a flame retardant as necessary, and then a sheet for a total heat exchanger having a moisture absorbing/releasing coating layer provided on one or both surfaces of the base paper is corrugated and then alternately laminated in a vertical and horizontal direction.

Further, the total heat exchanger includes the following (for example, see patent document 2): the corrugated sheet is joined to the liner sheet by a non-hygroscopic corrugated sheet having a non-hygroscopic texture made of a polypropylene film, and each section is orthogonal to the direction of the wave.

Further, the following heat exchanger is provided (for example, see patent document 3): a corrugated partition board in which a flame retardant is impregnated into base paper obtained by mixing a paper-making ceramic fibrous substrate and a plant fibrous substrate is laminated in multiple layers with a flat partition board in which the flame retardant and a moisture absorbent are impregnated into the same base paper.

Patent document 1: JP-A10-212691 (pages 3 to 4, FIG. 1)

Patent document 2: japanese patent laid-open No. 2001-241867 (page 2, FIG. 1)

Patent document 3: japanese patent laid-open publication No. S54-44255 (page 1, page 2, figure)

These conventional heat exchanger element partition members are characterized in that the flame retardant and the moisture absorbent are inevitably stacked in layers or mixed on any one of the total heat exchanger paper, the spacer sheet and the partition plate.

However, the conventional structure in which the flame retardant and the moisture absorbent are stacked as described above has the following problems.

(1) Since the moisture absorbent layer and the flame retardant layer are present in the conventional structure in addition to the moisture absorbent layer in the movement direction of moisture, if the latent heat between 2 air flows flowing through the front and rear surfaces of the partition member, that is, if the moisture is moved, the moisture absorbent layer absorbs the moisture, the flame retardant layer is formed to resist the movement of the moisture, and the amount of movement of the moisture in the part is reduced, resulting in a decrease in the moisture permeability of the partition member.

(2) Therefore, in order to further secure high moisture permeability, a method of increasing the amount of the moisture absorbent is considered. However, since the total amount of the agent that can be applied or permeated per unit area of the base material of the divided member is limited at that time, in the conventional structure in which the moisture absorbent and the flame retardant are applied to the same portion of the divided member, if the amount of the moisture absorbent is increased, the amount of the flame retardant is decreased, and the flame retardant is decreased. The opposite is also true, and as a result, there is a problem that the moisture absorption and flame retardancy are in a trade-off relationship.

(3) Further, since the moisture absorbent and the flame retardant are used in the same part, it is necessary to pay attention to the selection of the chemical agent so that the reaction does not easily occur by the contact. This also has a problem that the selection range of the moisture absorbent and the flame retardant is narrowed. The narrow range also causes high cost of the product and should be avoided as much as possible.

Further, as described in patent document 3, a structure in which moisture absorption and flame retardancy are imparted simultaneously can be provided by a method of permeating a moisture-absorbing flame retardant into a divided member. However, since the moisture absorption property is inferior to that of the moisture absorbent, it is difficult to improve the exchange efficiency by using the moisture absorbent alone or more. Such a drug is similar to the above-mentioned problem (3) in the limitation of the kind.

Disclosure of Invention

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to prevent the effect of a material such as a moisture absorbent having moisture permeability from being inhibited by a material such as a flame retardant having flame retardancy, to thereby achieve a more significant moisture permeability effect, and as a result, to improve the heat exchange efficiency of a total heat exchange element.

Further, the 2 nd object is to set the amounts of materials such as a moisture absorbent to which moisture permeability is imparted and a flame retardant to which flame retardancy is imparted freely without being bound to each other, and to achieve both improvement of heat exchange efficiency of a total heat exchange element and flame retardancy by making it possible to select them independently of their reactivity.

The total heat exchange element according to the first aspect of the present invention is a total heat exchange element in which two kinds of air flows are passed through both surfaces of a partition member holding a space by a space holding member, and heat exchange is performed between the two kinds of air flows by the partition member, wherein the partition member is a material obtained by coating or impregnating a porous base material with a moisture absorbent and coating a pore stopper for blocking pores, and the space holding member is a material obtained by coating or impregnating a base material with a flame retardant.

A total heat exchange element according to a second aspect of the present invention is a total heat exchange element in which two kinds of gas flows are passed through both surfaces of a partition member holding a space by a space holding member, and heat exchange is performed between the two kinds of gas flows by the partition member, wherein the partition member is formed by bonding a non-porous film member having hygroscopicity and gas-shielding properties to a porous base material, and the space holding member is a material obtained by coating or impregnating a base material with a flame retardant.

The total heat exchange element of the present invention is an element in which a moisture-permeable portion for imparting moisture permeability and a flame-retardant portion for imparting flame retardancy do not overlap in 1 member of a partition member and a space holding member.

In the partition member and the space holding member, since the moisture permeability imparting portion imparting moisture permeability and the flame retardancy imparting portion imparting flame retardancy do not overlap in 1 member, the effect of the material such as the moisture absorbent imparting moisture permeability is not inhibited by the material such as the flame retardant imparting flame retardancy by overlapping, the moisture permeability effect can be made more remarkable, as a result, the moisture permeability effect can be improved, and the improvement of the heat exchange efficiency of the total heat exchange element and the flame retardancy can be simultaneously achieved.

Drawings

Fig. 1 is a perspective view showing a total heat exchange element 1 according to embodiment 1 of the present invention;

fig. 2 is a perspective view showing a unit structural member of the total heat exchange element of fig. 1;

FIG. 3 is a cross-sectional view taken perpendicular to the path of the unit structural member of FIG. 2;

fig. 4 is a cross-sectional view in a direction perpendicular to a passage of a unit structural member of a total heat exchange element according to embodiment 2 of the present invention;

Detailed Description

Example 1

The total heat exchange element of embodiment 1 of the present invention is explained in detail with reference to the drawings. Fig. 1 shows a total heat exchange element 1 according to example 1 of the present invention, and the total heat exchange element 1 is configured by alternately laminating a flat plate-shaped divided member 2 and a space holding member 3 having a wave shape such as a sawtooth shape or a sine wave shape in cross section and processed so that a projection shape on a plane of the divided member 2 matches the divided member. The lamination method is, as shown in fig. 2, to produce unit structural members in which 1 divided member 2 and 1 space holding member 3 are overlapped so as to be in contact with the wavy convex portion and fixed by adhesion or the like, and to laminate the unit structural members so that the divided members 2 and the space holding members 3 alternate with each other, and so that the opening direction of the wave-shaped opening of the space holding members 3 alternately becomes substantially 90 degrees (fig. 1 is an example of a total heat exchange element in which 6 unit structural members are laminated). Thus, as shown in fig. 1, a total heat exchange element 1 in which 2 kinds of air flow paths 4 and 5 (indicated by arrows) alternately intersect in every other layer can be obtained. If two airflows in different states are passed through the passages 4 and 5 for the 2 airflows by a blower or the like, the partition member 2 can be used as a medium to exchange sensible heat and latent heat between the two airflows.

Fig. 3 is a cross-sectional view of the unit component of fig. 2, taken perpendicularly in the direction of air flow through the passages 4, 5. The partitioning member 2 and the space holding member 3 of the total heat exchanger element 1 have the following configurations in order to ensure moisture permeability, gas barrier properties, and flame retardancy.

First, the partition member 2 is composed of a base material 2a and a moisture absorbent 2b added to the base material 2a, the base material 2a is a cellulosic (セルロ - スベ - ス) material, for example, a non-porous pulp fiber material (paper made by beating pulp) or a gas-impermeable microporous base material, and the moisture absorbent 2b is impregnated or coated on the base material 2a with an alkali metal salt such as lithium chloride or calcium chloride as the moisture absorbent 2 b. Similarly, the spacer 3 is made of a material which allows a flame retardant such as guanidine hydrochloride or guanidine sulfamate to permeate through pulp fibers. The partition members 2 and the space holding members 3 are bonded together with an adhesive such as a vinyl acetate adhesive to form a unit component as shown in fig. 3.

The base material 2a of the partition member 2 is preferably as thin as possible because it is resistant to moisture movement. However, if the thickness is made thin, the material strength is drastically reduced, and the processing becomes difficult, so that the thickness is preferably about 25 μm to 150 μm. Further, the substrate 2a is provided with a gas barrier property, and therefore a non-porous film material is used. Since the non-porous material cannot pass water vapor through the pores as in the porous material, it is estimated that the moisture first permeates the partition member 2 in a form of adsorbing moisture, permeating, and diffusing the moisture on the surface of the partition member 2. From such a principle, it is preferable to use a hydrophilic material having a hydrophilic group such as a hydroxyl group and having good moisture diffusibility as a material of the base 2a of the partition member 2.

The base material of the spacer member 3 is made of general pulp, and guanidine salts of the flame retardant, i.e., flame retardant paper, are simultaneously used in the paper-making step. The flame retardancy grade is about 2 grade (JIS A1322, flame retardancy test method of thin building material). Alternatively, a material in which a flame retardant is impregnated or coated on one surface or both surfaces of paper may be used. However, in the case of single-side coating processing, the effect is weak in the case of heating the opposite side of the coated processing side. The thickness is preferably as thick as possible and the strength is high in consideration of its function to form and maintain the passage. However, in the case where the thin divided members 2 are bonded to the thick spacer 3 to form a unit structural member as shown in fig. 2, the structural member itself is bent due to a difference in dimensional change and a difference in strength caused by moisture absorption of the two members 2 and 3 after the processing. In this case, workability is seriously deteriorated when the element is formed into a shape as shown in fig. 1 by laminating the layers thereafter, and therefore, it is necessary to determine the thickness in consideration of this factor. In this case, approximately 100 μm.

In the total heat exchanger element 1 configured as described above, since the divided members 2 serving as media during heat exchange do not overlap with another chemical such as a flame retardant, the material (1) that resists the movement of moisture absorbed by the moisture absorbent is only the base material 2a of the divided members 2, and the effect of the moisture absorbent can be made more remarkable as compared with the conventional one, and the moisture permeability of the divided members 2 themselves can be improved. (2) The amount of the moisture absorbent to be used can be freely determined without being affected by the amount of the flame retardant to be used. The moisture absorbent has the effect of increasing the maximum usage amount of the moisture absorbent compared with the prior art. These effects can be achieved to achieve the final effect, to improve the latent heat exchange power of the total heat exchange element 1, and to achieve the significant effect of the moisture absorbent, so that the amount of the moisture absorbent used can be reduced while maintaining the same performance as that of the conventional case. In this case, an effect of cost reduction can be obtained. (3) Further, since the moisture absorbent is not mixed with the flame retardant, a chemical which has not been used so far due to the reactivity of the moisture absorbent and the flame retardant can be used, and therefore, there is an effect of expanding the range of selection of the chemical. This allows inexpensive and effective medicaments to be selected and used from an expanded range, resulting in cost reduction.

In order to verify these effects, tests were conducted on the total heat exchange element 1 of the present configuration and on a laminated total heat exchange element using both a partition member formed by coating a moisture absorbent on a flame-retardant base material obtained by adding a flame retardant to a porous material of a conventional example and a space holding member formed of paper as a general porous member, to compare latent heat and enthalpy exchange power when the dimensions of the element and the conditions for circulating an air flow were the same. The results are shown in table 1.

TABLE 1

Kinds of total heat exchange elements	Latent heat exchange efficiency ratio	Enthalpy exchange efficiency ratio
			Total heat exchange element of comparative example	1	1
The total heat exchange element	1.2	1.18

Accordingly, the total heat exchange element 1 can improve the latent heat exchange efficiency by about 20% and the enthalpy exchange efficiency by about 18%. Considering that the ratio is changed according to conditions and the like, it is determined that the effect of improving the exchange efficiency can be obtained in the case where the present total heat exchange element 1 is configured.

The flame retardancy of the total heat exchange element 1 is imparted by the flame retardant contained in the space holding member 3. As can also be seen from fig. 2 and the like, the space holding member 3 has a larger area than the divided members 2, and therefore can be coated with a flame retardant more than the material to which the flame retardant is added only to the divided members 2.

In order to make the degree of flame retardancy of the total heat exchange element 1 obvious, table 2 shows the results of the combustion test specified in UL-723, which is one of the U.S. specifications, with respect to 3 examples in which the total heat exchange element 1, the total heat exchange element to which the flame retardant treatment was applied only to the divided members, and the flame retardant treatment was applied to both the divided members and the space holding members.

TABLE 2

Kinds of total heat exchange elements	Diffusivity of combustion	Amount of smoke generated
			Conventional example 1 (flame retardant treatment in the partition Member and spacer holding Member)	0	0
Conventional example 2 (flame retardant treatment only in the divided parts)	10	55
			The present Total Heat exchange element (flame retardant treatment carried out only in the spacer holding Member))	10	5

Thus, the total heat exchange element 1 has the following results: the flame retardancy is very high as compared with the flame retardancy treatment performed only in the divided member, even close to the flame retardancy of the flame retardancy treatment applied in both the divided member and the space holding member. Therefore, if the flame retardant treatment is applied only to the space holding member 3, a practically sufficient flame retardancy can be obtained.

As described above, if the present structure is adopted for the laminated total heat exchange element, it is possible to improve the latent heat exchange efficiency by the remarkable action of the moisture absorbent, the increase of the maximum usable energy, and the like, and to ensure practically sufficient flame retardancy.

In the total heat exchange element 1 described above, a non-porous membrane material is used as the base material of the partition member 2 in order to ensure gas-shielding properties, but a porous membrane material may be used. However, in this case, in order to ensure gas-shielding properties, it is necessary to apply a plugging agent for plugging the holes. By using polyvinyl alcohol (PVA) or the like having moisture permeability and barrier property as the pore stopper, the pore can be stopped without inhibiting the effect of the moisture absorbent as much as possible. This provides substantially the same effect as that of the total heat exchange element 1.

In the case where a porous material is similarly used as the base material of the partition member 2, the same effect can be obtained by using a member having gas-shielding properties and moisture-absorbing properties, that is, a non-porous film made of a polymer material or the like having high moisture-absorbing properties comparable to those of the moisture-absorbing agent, instead of using the pore stopper. In this case, if a material having a high porosity and good air permeability is selected as thin as possible, such as a nonwoven fabric, in order to reduce the resistance to moisture migration of the base material, the resistance can be reduced, and the moisture absorption of the entire partition member 2 can be further improved.

As described above, the gas-shielding property is maintained in the base material of the partition member 2, and the base material of the space holding member 3 can be widely used from a non-porous base material to a porous base material.

In the total heat exchange element 1 of the present embodiment, the divided members 2 are provided as moisture permeability imparting portions for imparting moisture permeability, and the space holding members 3 are provided as flame retardancy imparting portions for imparting flame retardancy, so that the moisture permeability imparting portions and the flame retardancy imparting portions can be separated from each other, and the moisture permeability effect in the divided members 2, the flame retardancy in the space holding members 3, and the effect of the material such as the moisture absorbent for imparting moisture permeability are not hindered by the material such as the flame retardant for imparting flame retardancy.

In the total heat exchange element 1 of the present embodiment, the partition member 2 is a non-porous substrate or a microporous substrate that does not allow passage of gas, and a moisture absorbent is provided in the substrate, and the substrate of the spacer member 3 is a substrate selected from the non-porous substrate to the porous substrate, and a flame retardant is provided in the substrate, whereby the partition member 2 can secure moisture permeability and prevent movement of gas such as carbon dioxide between two gas flows, that is, gas shielding property, by using the non-porous substrate or the microporous substrate that does not allow passage of gas.

In the total heat exchange element 1 of the present embodiment, the partitioning member 2 is a porous base material, and a pore stopper having gas-shielding properties and a moisture absorbent are provided to the base material, or a member having gas-shielding properties and moisture absorbent properties is provided to the base material, and the base material of the space holding member 3 is a base material selected from a non-porous base material to a porous base material, and a flame retardant is provided to the base material, whereby the partitioning member 2 can secure gas-shielding properties by the pore stopper or the gas-shielding material, and at the same time, can secure moisture-permeability by the porous base material. In particular, when a member having gas-shielding properties and moisture-absorbing properties is provided to the base material, the moisture permeability can be significantly improved while ensuring the gas-shielding properties.

Example 2

Fig. 4 is a view showing a total heat exchanger element according to example 2 of the present invention, and is a cross-sectional view of the unit structural member shown in fig. 2 cut in a direction perpendicular to an air passage formed by the space holding member.

In the total heat exchange element 1, a process flame retardant 2c (guanidine-based flame retardant) is applied to the base material 2a of the portion of the partition member 2 connected to the space holding member 3, and a process moisture absorbent 2b is applied to the other portion. As the moisture absorbent 2b, a material containing an alkali metal salt such as lithium chloride or calcium chloride as a main component is used. The spacer 3 is made of flame-retardant paper permeable to a flame retardant of guanidine salts such as guanidine hydrochloride and guanidine sulfamate. The structure of fig. 4 is formed by gluing the partition member 2 and the spacer holding member 3, which is the same as in example 1, with an adhesive (e.g., a vinyl acetate adhesive).

In the total heat exchanger element 1, similarly to the total heat exchanger element 1 of example 1, the moisture absorbent 2b and the flame retardant are not overlapped in the portion of the partition member 2 that is not connected to the space holding member 3 and that actually moves by moisture, and therefore, the same effects as those of the total heat exchanger element 1 of example 1, such as improvement of the latent heat exchange efficiency, can be obtained. Further, since the amount of the flame retardant and the coating processing area are larger than those in the case where the base material 2a of the partition member 2 is not coated, high flame retardancy can be obtained.

In the case of this structure, since the flame retardant 2c and the moisture absorbent 2b are connected to the edge of the respective coating processing portions, it is necessary to consider the reactivity of the moisture absorbent 2b and the flame retardant 2c, and the other embodiments are more suitable particularly for the total heat exchange element 1 requiring high flame retardancy.

In the total heat exchange element 1 of the present example, the joint portion of the partition member 2 and the space holding member 3 is made to be a flame retardancy-imparting portion for imparting flame retardancy, the portion other than the joint portion is made to be a moisture-permeable portion for imparting moisture absorption, and the space holding member 3 is made to be a flame retardancy-imparting portion for imparting flame retardancy, whereby flame retardancy can be imparted to the joint portion which hardly affects moisture permeability, and flame retardancy can be increased without impairing moisture permeability.

The total heat exchange element 1 according to examples 1 and 2 of the present invention is structurally characterized in that the moisture absorption imparting portion formed by imparting a moisture absorbent or the like to the divided member 2 and the space holding member 3 and the flame retardancy imparting portion formed by imparting a flame retardant are configured so as not to overlap with each other in the divided member 2 and the space holding member 3, and in that the moisture absorption (moisture permeability) and/or the flame retardancy are not adversely affected by the interference between the moisture absorption imparting portion and the flame retardancy imparting portion. In the range that meets the present gist, widely known methods can be used for selection of a moisture absorbent (moisture absorption imparting material), a flame retardant (flame retardancy imparting material), and the like, and a method of imparting both members to a substrate.

As described above, the total heat exchange element according to the present invention can be effectively used in a heat exchange device that performs heat recovery when exchanging heat with outdoor air, such as ventilation of indoor air, in the field of air conditioning such as air conditioners and ventilators.

Claims (3)

1. A total heat exchange element in which two kinds of air flows are passed through both surfaces of a partition member having a space held by a space holding member, and heat exchange is performed between the two kinds of air flows by the partition member,

the partition member is a material in which a porous base material is coated or impregnated with a moisture absorbent and a pore blocking agent for blocking the pores is applied,

the spacer holding member is a material in which a base material is impregnated or coated with a flame retardant.

2. A total heat exchange element in which two kinds of air flows are passed through both surfaces of a partition member having a space held by a space holding member, and heat exchange is performed between the two kinds of air flows by the partition member,

the partition member is formed by bonding a non-porous film member having hygroscopicity and gas-shielding properties to a porous base material,

the spacer holding member is a material in which a flame retardant is coated or impregnated on a base material.

3. The total heat exchange element according to claim 1 or 2, wherein a flame retardant is applied to a portion of the base material constituting the divided member which is in contact with the space holding member, and a moisture absorbent is applied to another portion of the base material constituting the divided member.