JP6937258B2 - Total heat exchange element sheet, total heat exchange element, and total heat exchanger - Google Patents

Description

The embodiment relates to a total heat exchange element sheet, a total heat exchange element, and a total heat exchanger.

In recent years, reduction of energy consumption has been required from the viewpoints of protection of the global environment, reduction of carbon dioxide, energy shortage, and the like. Living spaces such as houses and buildings require ventilation required by the Building Standards Law. However, air conditioning energy loss due to ventilation has become a problem. A total heat exchanger, which is one of the air conditioners, exchanges total heat (sensible heat (temperature) and latent heat (humidity)) between the temperature-controlled and humidity-controlled air inside the building and the outdoor air. This is a device that suppresses heat loss and saves energy.

The conventional total heat exchange element uses a sheet for total heat exchange element made of specially processed paper, and exchanges sensible heat and latent heat while suppressing mixing of indoor air and outdoor air. .. However, the total heat exchange efficiency of the total heat exchange element sheet remains as low as around 70%. By replacing the sheet for the total heat exchange element with a material having higher exchange efficiency, it is possible to realize a total heat exchanger with further energy saving.

Tokukousho 61-058759 Gazette Japanese Unexamined Patent Publication No. 2004-154457 Japanese Unexamined Patent Publication No. 2010-234213

In the embodiment, a total heat exchange element sheet having an improved water vapor permeation rate, a total heat exchange element provided with a total heat exchange element sheet, and total heat exchange while maintaining the separation rate between water vapor and a gas other than water vapor. It is an object of the present invention to provide a total heat exchanger in which an element is incorporated.

The sheet for a total heat exchange element according to the embodiment includes a porous member and a film provided on one surface of the porous member and containing inorganic fibers having a fiber diameter of 1 nm or more and 50 nm or less. The film has a multi-layer structure in which two or more thin layers having different orientation states of inorganic fibers are laminated.

It is sectional drawing which shows the sheet for total heat exchange element which concerns on embodiment. It is sectional drawing which made the flow of outside air and return air different from FIG. 1 with respect to the sheet for total heat exchange element. It is sectional drawing which shows typically the sectional TEM photograph of the film of FIG. It is a perspective view which shows the total heat exchange element which concerns on embodiment. It is the schematic which shows the total heat exchanger which concerns on embodiment for demonstrating the total heat exchange in summer. It is the schematic which shows the total heat exchanger which concerns on embodiment for demonstrating the total heat exchange in winter.

Hereinafter, embodiments will be described with reference to the drawings. In each embodiment, substantially the same constituent parts may be designated by the same reference numerals, and the description thereof may be partially omitted. The drawings are schematic, and the relationship between the thickness and the plane dimensions, the ratio of the thickness of each part, etc. may differ from the actual ones. The terms indicating the up and down directions in the explanation may differ from the actual direction based on the gravitational acceleration direction.

FIG. 1 is a schematic cross-sectional view showing a sheet for a total heat exchange element according to an embodiment, FIG. 2 is a schematic cross-sectional view showing the flow of outside air and return air with respect to the sheet for a total heat exchange element, and FIG. FIG. 1 is a cross-sectional view schematically showing a cross-sectional TEM photograph of the film of FIG. The sheet 1 for a total heat exchange element includes a porous member 2 and a film 3 provided on one surface of the porous member 2, and the laminated body of the porous member 2 and the film 3 serves as a water vapor separator. Has a function.

Normally, the introduction side of the total heat exchange element sheet 1 is not changed in consideration of cost and the like, but the introduction side may be changed between summer and winter as described below.

For example, when the outside air 110a is hotter and more humid than the return air 110c, as shown in FIG. 1, the outside air 110a mainly circulates on the surface of the membrane 3 along a flow path (not shown) and enters the room as an intake air 110b. The return air 110c is discharged, mainly passes through the surface of the porous member 2 along a flow path (not shown), and is discharged to the outside as an exhaust 110d. The outside air 110a and the return air 110c are circulated so as to face each other, for example, but may be circulated so as to intersect each other at an angle due to the design of total heat exchange. By circulating the outside air 110a along the film 3 surface of the total heat exchange element sheet 1 and the return air 110c along the surface of the porous member 2 of the total heat exchange element sheet 1 in this way, the water vapor contained in the outside air 110a. And the heat passes through the total heat exchange element sheet 1 and moves to the return air 110c side adjusted to low humidity and low temperature.

On the other hand, when the outside air 110a has a lower temperature and lower humidity than the return air 110c, the return air 110c mainly passes through the surface of the membrane 3 along the flow path (not shown) as an exhaust 110d as shown in FIG. The outside air 110a mainly passes through the surface of the porous member 2 along a flow path (not shown) and is discharged indoors as an intake air 110b. The return air 110c and the outside air 110a are distributed so as to face each other. By circulating the return air 110c along the surface of the film 3 of the total heat exchange element sheet 1 and the outside air 110a along the surface of the porous member 2 of the total heat exchange element sheet 1 in this way, the return air 110c is included in the return air 110c. Water vapor and heat (sensible heat and latent heat) pass through the total heat exchange element sheet 1 and move to the outside air 110a side. Therefore, the total heat exchange element sheet 1 can exchange total heat between the outside air 110a and the return air 110c.

It is preferable that the outside air and the return air pass through the surface of the total heat exchange element sheet 1 along the flow path so as not to come into contact with each other, and the water vapor and other gases are efficiently separated. Therefore, the total heat exchange element sheet 1 is required to have a function of efficiently exchanging temperature and humidity. In order to further increase the total heat exchange efficiency, for example, it is preferable that both the water vapor permeation rate Vs and the separation rate α indicating the ability to separate water vapor and a gas (air or the like) excluding water vapor are high.

The water vapor permeation rate Vs of the total heat exchange element sheet 1 is required to be ^{50 g / h / m 2} / kPa or more, 80 g / h / m ² / kPa, and further 120 g / h / m ^{2 / kPa.} The water vapor permeation rate Vs of the total heat exchange element sheet is represented by the following equation (1). If the water vapor permeation rate Vs of the total heat exchange element sheet 1 is low, the humidity exchange efficiency may decrease and the loss as a total heat exchanger may increase.

The water vapor permeation rate Vs (g / h / m ² / kPa) of the total heat exchange element sheet 1 = (the amount of water permeated through the total heat exchange element sheet 1 (g)) / (the total heat exchange element sheet 1 Time permeated by water (h)) / (Area of total heat exchange element sheet 1 (m ² )) / (Water vapor pressure difference (kPa) on both sides of total heat exchange element sheet 1) ... (1)
The separation ratio α between the water vapor and the gas excluding water vapor of the total heat exchange element sheet 1 is required to be 10 or more, 20 or more, and further 50 or more. The separation rate α is expressed by the following equation (2).

α = [(the number of moles of water that has passed through the sheet 1 for the total heat exchange element) / (the number of moles of dry air in the exhaust 7d)] / [(the number of moles of water in the outside air 7a) / (the number of moles of the dry air in the outside air 7a) Number of moles)] ... (2)
If the separation rate α is too low, it becomes difficult to separate water vapor from the gas other than water vapor, and the return air cannot be efficiently performed. As a result, the emission of carbon dioxide and the like in the room is reduced, and an extra air volume is required for sufficient ventilation.

The above-mentioned porous member 2 and membrane 3 will be described in detail below.
<Porous member 2>
The porous member 2 preferably contains an organic fiber having a fiber diameter of 1 μm or more and 100 μm or less as a main component. It is more preferable that the organic fiber has a fiber diameter of 1 μm or more and 50 μm or less. Organic fibers are preferred because they have high flexibility and low cost. The porous member 2 may contain a plurality of types of organic fibers. Further, the porous member 2 may contain an additive of 10% by weight or less, for example, a sizing agent for adjusting the size of paper, a water-repellent or water-resistant treatment agent, and the like.

The porous member 2 preferably has additional pores between the organic fibers. By adjusting the fiber diameter to a range of 1 μm or more and 100 μm or less to control the pore diameter and the like, the water vapor permeation rate Vs and the like of the porous member 2 can be increased.

As the organic fiber, for example, synthetic fiber, natural fiber and the like can be used. Natural fibers contain, for example, cellulose as a main component. The organic fibers may be flat in the radial direction. Further, the organic fiber may be a hollow fiber. The porous member 2 may be, for example, a non-woven fabric, paper, an organic porous body, or a molded body (including paper) made of synthetic fibers or natural fibers. The organic fiber constituting the porous member 2 may be an aggregate of organic nanofibers having a size of submicron or less. By using an aggregate of organic nanofibers, the bonding force between the porous member 2 and the membrane 3 can be increased, and the membrane 3 can be prevented from peeling from the porous member 2.

The porous member 2 may be produced from a porous sheet obtained by stretching a fluorine-based sheet such as Poaflon (registered trademark of Sumitomo Electric Industries, Ltd.).

The average pore diameter of the porous member 2 is preferably 0.05 μm or more and 100 μm or less, more preferably 0.05 μm or more and 50 μm or less, and further preferably 0.1 μm or more and 10 μm or less. If the average pore diameter is too large, when the film 3 is formed on the porous member 2, the film 3 easily penetrates into the pores, and pinholes and cracks may occur to deteriorate the separation performance.

The thickness of the porous member 2 is not particularly limited, but is preferably 30 μm or more and 3 mm or less, and more preferably 50 μm or more and 1 mm or less. If the porous member 2 is made too thin, deformation such as bending occurs during handling, and the film 3 provided on one surface of the porous member 2 may not only have defects such as cracks but also be damaged. Further, if the porous member 2 is made too thick, not only the water vapor permeation rate Vs is lowered, but also the heat conduction is lowered, so that there is a concern that heat exchange loss may occur.

The density of the porous member 2 is preferably 0.8 g / cm ³ or less, more preferably 0.7 g / cm ³ or less. If the density is too high, the permeation resistance of water vapor becomes high, and the total heat exchange efficiency may decrease.

The volume porosity (volume fraction of pores) of the porous member 2 is preferably 20% or more and 80% or less, and more preferably 25% or more and 70% or less. If the volume porosity of the porous member 2 is less than 20%, the permeation resistance of water vapor becomes high, and the total heat exchange efficiency may decrease. When the volume porosity of the porous member 2 exceeds 80%, the strength of the porous member 2 decreases, cracks occur in the film 3 provided on one surface of the porous member 2, and a wet seal described later is formed. There is a risk of hindering. The volume porosity and the shape of the pores (average pore diameter, etc.) of the porous member 2 can be measured by the mercury press-fitting method.

The water vapor permeation rate Vs of the porous member 2 is preferably 50 g / h / m ² / kPa or more, 70 g / h / m ² / kPa or more, and more preferably 120 g / h / m ² / kPa or more. The water vapor permeation rate Vs of the porous member 2 is represented by the following equation (3).

Water vapor permeation rate Vs (g / h / m ² / kPa) of the porous member 2 = (amount of water permeated through the porous member 2 (g)) / (time permeated through the porous member 2 (h)) / (Area of porous member 2 (m ² )) / (Water vapor pressure difference (kPa) on both sides of porous member 2) ... (3)
If the water vapor permeation velocity Vs of the porous member 2 obtained by the above formula (3) is too low, the water vapor permeation velocity Vs of the entire sheet for the total heat exchange element may decrease, and the total heat exchange efficiency may decrease.
<Membrane 3>
The membrane 3 is provided on one surface of the porous member 2. The film 3 contains inorganic fibers having a fiber diameter of 1 nm or more and 50 nm or less. Inorganic fibers having an OH group are preferable because water vapor is easily adsorbed. The fiber length of the inorganic fiber is preferably 0.5 μm or more and 15 μm or less. It is more preferable that the inorganic fiber has a fiber diameter of 1 nm or more and 10 nm or less and a fiber length of 1 μm or more and 3 μm or less. If the fiber length is shorter than 0.5 μm, the force with which the fibers are entangled with each other is small, and cracks may easily occur when the film is formed. If the fiber length is longer than 15 μm, the aspect ratio with respect to the fiber diameter becomes too large and the fiber tends to break. Inorganic fibers are preferable because they have high heat resistance. The film 3 may contain a plurality of types of inorganic fibers.

The inorganic fiber 31 is not particularly limited, but is preferably a hydrophilic material. The hydrophilic material is at least one selected from the group consisting of, for example, aluminum (Al), silicon (Si), titanium (Ti), zirconium (Zr), zinc (Zn), magnesium (Mg), and iron (Fe). Oxides and hydroxides containing: Aluminosilicates containing at least one selected from the group consisting of alkali metals and alkaline earth metals; from the group consisting of magnesium (Mg), calcium (Ca), and strontium (Sr). Carbonates containing at least one selected; phosphates containing at least one selected from the group consisting of Mg, Ca, and Sr; containing at least one selected from the group consisting of Mg, Ca, Sr, and Al. Titanate; or a composite or mixture thereof, etc. can be used. Further, it may be a metal compound formed by using a metal hydroxide as a precursor, binding the metal hydroxide by hydrolysis or the like, stopping the reaction in the middle, and controlling the number of OH groups.

Specific hydrophilic materials include, for example, alumina (including boehmite or pseudo-boehmite), silica, titania, zirconia, magnesia, zinc oxide, ferrite, zeolite, hydroxyapatite, barium titanate, or a hydrate thereof. However, it is not limited to these. The film 3 containing the inorganic fiber made of such a hydrophilic material can further improve the heat resistance.

It is particularly preferable that the inorganic fiber contains boehmite or pseudo-boehmite. Pseudo-boehmite is a material containing alumina hydrate, which has a partially different crystal structure from boehmite. Since boehmite and pseudo-boehmite have many OH groups on the surface and between layers of crystals, they easily adsorb water vapor and are advantageous for forming a wet seal.

The film 3 has a multilayer structure in which two or more thin layers having different orientation states of inorganic fibers are laminated. As the thin layers having different orientation states of the inorganic fibers, the first thin layer 31 and the second thin layer 32 shown in FIG. 3 are arranged alternately, for example. The first thin layer 31 and the second thin layer 32 have the structure described below.

(1) In the first thin layer 31, the orientation of the inorganic fibers is random when the thin layer 31 is viewed in a plan view, and the inorganic fibers are parallel to the surface of the thin layer 31 when the thin layer 31 is viewed in cross section. And / or tilt and orient.

(2) In the second thin layer 32, one end surface and / or one end portion of the inorganic fiber appears when the thin layer 32 is viewed in a plan view, and the inorganic fiber is formed in the thin layer 32 when the thin layer 32 is viewed in cross section. Oriented parallel to and / or tilted with respect to the axis perpendicular to the surface.

Here, in the first thin layer 31 of the above (1), "the orientation of the inorganic fibers is random when viewed in a plan view" means that the inorganic fibers aligned in a specific direction with respect to the surface of the thin layer 31 It is less than 50% of the total inorganic fiber. "Random orientation of inorganic fibers when viewed in a plan view" means that less than 40% of the total inorganic fibers are aligned in a specific direction with respect to the surface of the thin layer 31, more preferably the total inorganic fibers. Less than 30%.

In the first thin layer 31 of the above (1), "the inorganic fiber is inclined with respect to the surface of the thin layer 31 when viewed in cross section" is preferably 0 to 30 ° with respect to the surface of the thin layer 31. Tilt at an angle, more preferably at an angle of 0-15 °.

In one embodiment, the first thin layer 31 has a mixture of orientations in which the inorganic fibers are parallel to and inclined with respect to the surface of the thin layer 31 when viewed in cross section. The mixing ratio of the two orientations is arbitrary.

In another embodiment, the first thin layer 31 has a mixture of orientations in which the inorganic fibers are inclined at different angles with respect to the surface of the thin layer 31 when viewed in cross section. The mixing ratio of orientations tilted at different angles is arbitrary.

Further, in the second thin layer 32 of the above (2), "one end surface and / or one end portion of the inorganic fiber appears when viewed in a plan view" means that, for example, one end of the inorganic fiber is fluffed on the surface of the thin layer 32. appear.

In the second thin layer 32 of (2), "the inorganic fiber is inclined with respect to the axis perpendicular to the surface of the thin layer 32 when viewed in cross section" is preferably 0 to 45 with respect to the axis perpendicular to the vertical axis. It is tilted at an angle of °, more preferably an angle of 0-30 °.

In one embodiment, the second thin layer 32 has a mixture of orientations in which the inorganic fibers are parallel to the axis perpendicular to the surface of the thin layer 32 and are inclined when viewed in cross section. The mixing ratio of the two orientations is arbitrary.

In another embodiment, the second thin layer 32 has a mixture of orientations in which the inorganic fibers are inclined at different angles with respect to the axis perpendicular to the surface of the thin layer 32 when viewed in cross section. The mixing ratio of orientations tilted at different angles is arbitrary.

In the first and second thin layers 31 and 32 described above, the first thin layer 31 has a higher density than the second thin layer 32 due to their structural differences.

If the multilayer structure constituting the membrane 3 has one first and one second thin layers 31 and 32 respectively, water vapor and water vapor can be maintained while maintaining a higher water vapor permeation rate than a membrane composed of a single layer. It has an advantageous effect of improving the separation rate of gas (for example, air) excluding water vapor.

The number of layers of the multi-layered film 3 including the first and second thin layers 31 and 32 is 6 or more, 8 or more, 10 or more, 12 or more, 14 or more, 16 or more, 18 or more. , 20 layers or more, 24 layers or more, 30 layers or more, 40 layers or more, or 50 layers or more. In the film 3 having a multilayer structure having such a number of layers, the plurality of first thin layers 31 or the plurality of second thin layers 32 to be laminated satisfy the orientation states (1) and (2) described above. Within the range, they may be the same or different from each other.

The layer thickness of the multi-layered film 3 (thickness of the first or second thin layer) is preferably 300 nm or less, more preferably 200 nm or less, still more preferably 100 nm or less. The thickness of the first or second thin layer may be the same as or different from each other. The lower limit thickness of the first or second thin layer is preferably 10 nm, more preferably 15 nm, and most preferably 30 nm.

The thickness of the multi-layered film 3 itself cannot be unconditionally defined by the thickness of the first and second thin layers and the number of layers, but for example, the thickness of the first and second thin layers is 300 nm or less, respectively. In the case, it is desirable to make it 1 to 50 μm, more preferably 1 to 20 μm.

Next, an example of a method for manufacturing a sheet for a total heat exchange element according to the embodiment will be described.

1) First, for example, a sheet-shaped porous member containing an organic fiber having a fiber diameter of 1 μm or more and 100 μm or less as a main component is prepared.

2) A sheet-shaped porous member is wound and fixed on a rotatable drum surface having a desired diameter.

3) Arrange the nozzles facing the drum. The nozzle reciprocates in the width direction of the porous member wound around the drum.

4) While rotating the drum, the nozzle reciprocates in the width direction of the porous member, and during that time, the dispersion liquid of inorganic fibers having a fiber diameter of 1 nm or more and 50 nm or less is directed from the nozzle to one surface (surface) of the porous member. And spray. The dispersion liquid of the inorganic fiber is, for example, a liquid in which the inorganic fiber is dispersed in water.

5) A sheet for a total heat exchange element in which a multi-layered film including a first and second thin layers is formed on one surface of the porous member by removing the sheet-shaped porous member from the drum and drying it. To manufacture.

The rotation speed of the drum in the step 4) is preferably 10 to 800 rpm. The reciprocating operation of the nozzle is preferably 1 to 10 cm / min.

The number of layers of the multi-layered film can be controlled by adjusting the spraying time of the dispersion liquid of the inorganic fibers in the step 4).

In the manufacturing method, the orientation state of the first and second thin layers of the film can be controlled mainly by the rotation speed of the drum and the spraying speed (flow rate) of the dispersion liquid of the inorganic fibers from the nozzle.

The sheet 1 for a total heat exchange element described above is porous because it includes a porous member 2 and a film 3 provided on one surface of the porous member and containing inorganic fibers having a fiber diameter of 1 nm or more and 50 nm or less. The member 2 can be responsible for a high water vapor permeation rate, and the membrane 3 can be responsible for a high water vapor permeation rate and a separation rate between water vapor and a gas other than water vapor.

Further, by forming the porous member into a form containing organic fibers having a fiber diameter of 1 μm or more and 100 μm or less, it is possible to realize a high water vapor permeation rate while imparting flexibility to the sheet itself.

On the other hand, when the film 3 contains an inorganic fiber having a fiber diameter of 1 nm or more and 50 nm or less, cracks in the film 3 due to film formation or bending of the sheet can be suppressed and the strength can be improved. It also has a flameproof effect. Further, since the membrane 3 composed of nano-sized inorganic fibers has pores formed between the inorganic fibers, water vapor contained in the outside air or the like is condensed by Kelvin's capillary condensation theory to fill the pores and become wet. Form a seal. The wet seal can adsorb water vapor contained in the outside air or the like and move it from the membrane 3 to the porous member 2. In addition, the wet seal can suppress the permeation of gas other than water vapor.

The film 3 is a multilayer in which two or more thin layers (first thin layer 31 and second thin layer 32) having different orientation states of the inorganic fibers are laminated in addition to the function of the inorganic fibers having a specific fiber diameter. Has a structure. In the first thin layer 31, the orientation of the inorganic fibers is random when the thin layer 31 is viewed in a plan view, and the inorganic fibers are parallel to the surface of the thin layer 31 and / / when the thin layer 31 is viewed in cross section. Or it is inclined and oriented. In the second thin layer 32, one end surface and / or one end portion of the inorganic fiber appears when the thin layer 32 is viewed in a plan view, and the inorganic fiber is perpendicular to the surface of the thin layer 32 when the thin layer 32 is viewed in cross section. Oriented parallel to and / or tilted with respect to the axis. In the first and second thin layers 31 and 32, the first thin layer 31 has a higher density than the second thin layer 32.

The film 3 having such a multi-layer structure has the following superior effects as compared with a film having a single-layer structure having a single orientation state.
(1) In the first thin layer 31, the inorganic fibers are oriented parallel to and / or inclined with respect to the surface of the thin layer 31 when viewed in cross section, so that more fine pores are formed between the inorganic fibers. be able to. The first thin layer 31 can form more of the wet seals described above. As a result, the adsorptivity of water vapor contained in the outside air that circulates in contact with the surface of the membrane 3 is improved, and the membrane 3 is moved from the membrane 3 to the porous member 2, that is, the water vapor permeation rate can be further increased. Further, by increasing the wet seal in the first thin layer 31, it is possible to effectively suppress the permeation of the gas other than water vapor, that is, the separation rate between the water vapor and the gas excluding water vapor can be further increased.
(2) In the second thin layer 32, the inorganic fibers are oriented parallel to and / or inclined with respect to the axis perpendicular to the surface of the thin layer 32 when viewed in cross section, so that water vapor is perpendicular to the surface of the thin layer 32. The water vapor permeation rate can be increased by moving the inorganic fibers parallel to and / or inclined with respect to the vertical axis along the orientation direction of the inorganic fibers.

Further, since the inorganic fibers of the first thin layer 31 are oriented in parallel and / or inclined with respect to the surface of the thin layer 31, cracks may occur along the orientation. The cracked portion causes a decrease in the strength of the film 3. The second thin layer 32 laminated on the first thin layer 31 functions as a cushioning material due to its orientation structure, and can compensate for the decrease in strength of the cracked portion of the first thin layer 31.
(3) The number of layers in which the first and second thin layers 31 and 32 exceed two layers, for example, the film 3 having a multilayer structure of 10 layers emphasizes the characteristics of the first and second thin layers 31 and 32. be able to. That is, by alternately laminating two or more layers of the first and second thin layers 31 and 32 in the thickness direction of the film 3, water vapor due to the wet seal formed on each of the first thin layers 31 is removed. The permeation of gas can be suppressed more effectively. At the same time, the formation of the wet seal in the first thin layer 31 and the increase in the water vapor permeation rate in each of the second thin layers 32 adjacent to the porous member 2 side with respect to the first thin layer 31. The interaction can further improve the water vapor permeation rate.

Further, since the inorganic fibers of each of the first thin layers 31 are oriented in parallel and / or inclined with respect to the surface of the thin layer 31, cracks may occur along the orientation. When the crack propagates in the thickness direction of the film, it not only breaks but also reduces the separation rate between water vapor and the gas other than water vapor. The second thin layer 32, which is arranged between the first thin layers 31, has a buffering action due to its orientation structure, and the cracks generated in the first thin layer 31 propagate in the thickness direction of the film 3. Block (disconnect). As a result, the film 3 having both high strength and excellent wet sealing property can be realized.

Next, the total heat exchange element according to the embodiment will be described in detail.

The total heat exchange element has a structure including a plurality of sheets for the total heat exchange element described above. FIG. 4 is a perspective view showing a total heat exchange element according to the embodiment. The total heat exchange element 10 includes a plurality of sheets, for example, six sheets 1 for the above-mentioned total heat exchange element, two reinforcing sheets 12a and 12b (arranged in the lowermost layer and the uppermost layer), and a plurality of sheets (for example). It is provided with a flow path member 13 having a cross-sectional waveform (7 sheets), for example, a triangular cross-sectional waveform.

The sheets 1 for total heat exchange elements are laminated with each other at regular intervals so that the film 3 is located on the lower surface. The reinforcing sheets 12a and 12b are arranged on the uppermost layer and the lowermost layer of the laminated body at regular intervals with respect to the total heat exchange element sheet 1. The flow path member 13 having a triangular cross section is alternately interposed and fixed between the reinforcing sheet 12a, the six total heat exchange element sheets 1 and the reinforcing sheet 12b so as to intersect at an angle of, for example, 90 °. .. The flow path member 13 is not particularly limited, but can be made of, for example, a corrugated paper sheet containing pulp as a main component, a general-purpose resin such as polyvinyl chloride or polypropylene, or a metal such as stainless steel. The first linear flow path 21 is formed by being surrounded by the film 3 of the total heat exchange element sheet 1 and the cross-section triangular wave of the flow path member 13 having a triangular cross-section waveform. The second linear flow path 22 is formed by being surrounded by the porous member 2 of the total heat exchange element sheet 1 and the cross-section triangular wave of the flow path member 13 having a triangular cross-section waveform. The first and second linear flow paths 21 and 22 are arranged so as to intersect each other at an angle of, for example, 90 ° with the total heat exchange element sheet 1 interposed therebetween.

Next, the total heat exchanger according to the embodiment will be described in detail.

The total heat exchanger includes the above-mentioned total heat exchange element. FIG. 5 is a schematic view showing a total heat exchanger according to an embodiment for explaining total heat exchange in summer. That is, the total heat exchanger 100 includes a housing 101. The total heat exchange element 10 shown in FIG. 4 described above is arranged in the housing 101.

Inside the housing 101, the first to fourth partition chambers 104a to 104d are partitioned by a horizontal partition wall 102 and a vertical partition wall 103 so as to surround the total heat exchange element 10. The first to fourth compartments 104a to 104d are open at locations facing the open ends of the first and second linear flow paths (not shown) of the total heat exchange element 10. The first to fourth compartments 104a to 104d are arranged in the upper left portion, the upper right portion, the lower left portion, and the lower right portion of the housing 101, respectively.

The left side walls 105a of the housing 101 in which the first and third compartments 104a and 104c are located are provided with first and third openings 106a and 106c, respectively. The right side walls 105b of the housing 101 in which the second and fourth compartments 104b and 104d are located are provided with the second and fourth openings 106b and 106d, respectively. A first fan 107a is arranged on the left side wall 105a where the third opening 106c in the third compartment 104c is located. A second fan 107b is arranged on the right side wall 105b where the fourth opening 106c in the fourth compartment 104d is located.

In the total heat exchanger 100 provided with such a total heat exchange element 10, total heat exchange is performed by the following operation.
<Total heat exchange during hot and humid summer season>
By driving the second fan 107b, the outside air (higher temperature and higher humidity than the return air) 110a indicated by the arrow from the outside passes through the fourth opening 106d and the fourth partition chamber 104d, and a plurality of first total heat exchange elements 10 are used. It circulates in contact with the surface of the film 3 of the total heat exchange element sheet 1 shown in FIG. 1 in the linear flow path (not shown) of No. 1, and further passes through the first partition chamber 104a and the first opening 106a. It is introduced into the room as the intake air 110b shown by the arrow. At the same time, by driving the first fan 107a, the return air 110c indicated by the arrow from the room flows through the third opening 106c and the third partition room 104c through a plurality of second linear flows of the total heat exchange element 10. It circulates in contact with the surface of the porous member 2 of the total heat exchange element sheet 1 shown in FIG. 1 in a path (not shown), and is further indicated by an arrow through a second partition chamber 104b and a second opening 106b. It is discharged to the outside as exhaust 110d.

In such a total heat exchange element 10, the outside air 110a is introduced into the first linear flow path (not shown) of the total heat exchange element 10, and the film 3 of the total heat exchange element sheet 1 shown in FIG. The return air 110c is circulated in contact with the surface, and is introduced into a second linear flow path (not shown) that intersects the first linear flow path with the total heat exchange element sheet 1 in between. It is circulated in contact with the surface of the porous member 2 of the total heat exchange element sheet 1 shown in 1. At this time, since the outside air 110a is hotter and more humid than the return air 110c, the water vapor and heat contained in the outside air 110a in the total heat exchange element 10 are transferred to the return air 110c side through the total heat exchange element sheet 1.
<Total heat exchange during low temperature and low humidity in winter>
In contrast to the total heat exchange in the summer described with reference to FIG. 5, the total heat exchange can be performed in the winter by circulating the outside air and the return air through the same flow path. Further, in the total heat exchange in winter, the introduction flow paths of the outside air and the return air, and the air supply directions by the first and second fans may be switched as shown in FIG. 6, respectively. FIG. 6 is a schematic view showing a total heat exchanger according to an embodiment for explaining total heat exchange in winter.

That is, by driving the second fan 107b, the return air 110c indicated by the arrow from the room flows through the first opening 106a and the first partition room 104a through the first linear flow of the total heat exchange element 10. The exhaust 110d indicated by the arrow is circulated in the path (not shown) in contact with the surface of the film 3 of the total heat exchange element sheet 1 shown in FIG. 1 and further passed through the fourth partition chamber 104d and the fourth opening 106d. Is discharged to the outside of the room. At the same time, by driving the first fan 107a, the outside air (lower temperature and lower humidity than the return air) 110a indicated by the arrow from the outside passes through the second opening 106b and the second compartment 104b, and the total heat exchange element 10 is the first. It circulates in contact with the surface of the porous member 2 in the linear flow path (not shown) of 2, and is further introduced into the room as an intake air 110b indicated by an arrow through a third partition chamber 104c and a third opening 106c. NS.

In such a total heat exchange element 10, the return air 110c is introduced into the first linear flow path (not shown) and comes into contact with the surface of the film 3 of the total heat exchange element sheet 1 shown in FIG. The outside air 110a is circulated and introduced into a second linear flow path (not shown) that intersects the first linear flow path with the total heat exchange element sheet 1 in between, and the total heat exchange is shown in FIG. It is circulated in contact with the surface of the porous member 2 of the element sheet 1. At this time, since the outside air 110a has a lower temperature and lower humidity than the return air 110c, the water vapor and heat contained in the return air 110c in the total heat exchange element 10 are transferred to the outside air 110a side through the total heat exchange element sheet 1.

Therefore, since the total heat exchange element 10 incorporated in the total heat exchanger 100 includes the total heat exchange element 1 having a high water vapor permeation rate Vs and a high separation rate α, the total heat is transferred between the outside air and the return air. It can be replaced efficiently.

The cross-sectional waveform of the flow path member 13 is not limited to a triangular cross-section waveform, but may be a rectangular cross-section waveform or a trapezoidal cross-section waveform. It is preferable that the cross-sectional waveform has substantially the same or the same shape of the peaks and valleys.

Hereinafter, examples will be described in detail.
(Example 1)
First, a sheet-shaped porous member having a thickness of 120 μm made of paper having an average diameter of 20 μm was prepared. A sheet-shaped porous member was wound and fixed on a rotatable drum surface having a diameter of 20 cm. The nozzle was placed facing the drum. The nozzle reciprocates in the width direction of the porous member wound around the drum. While rotating the drum at a speed of 600 rpm, the nozzle is reciprocated on one surface (surface) of the sheet-shaped porous member at a speed of 5 cm / min, during which the pseudo-bemite nano with an average diameter of 4 nm and an average length of 1 μm is reciprocated. An aqueous dispersion containing fibers was sprayed from the nozzle toward the surface of the porous member. Then, by drying, a film having a thickness of 20 μm was formed on the surface of the porous member to produce a sheet for a total heat exchange element.

The cross section of the film of the obtained total heat exchange element sheet was observed by TEM. As a result, the membrane is composed of pseudo-boehmite nanofiber layers (first thin layer and second thin layer) having different orientations alternately laminated, and each layer has a thickness of 50 to 100 nm and a number of layers of 25. It was confirmed that it was a certain laminated film.

In the first thin layer, the orientation of the pseudo-bemite nanofibers appearing on the surface of the membrane when viewed in a plan view is random, and the pseudo-bemite nanofibers oriented parallel to the surface of the membrane account for less than 30% of the entire surface of the membrane. Met. In the first thin layer, the orientation in which the pseudo-boehmite nanofibers were parallel to the film surface and the orientation in which the pseudo-boehmite nanofibers were inclined at an angle of 0 to 10 ° were mixed when viewed in cross section.

On the other hand, when the second thin layer was viewed in a plan view, one end surface and one end portion of the pseudo-boehmite nanofiber appeared on the surface of the second thin layer. In the second thin layer, when viewed in cross section, the pseudo-boehmite nanofibers were mixed with an orientation parallel to the axis perpendicular to the film surface and an orientation inclined at an angle of 0 to 30 °.
(Example 2)
A fluororesin porous sheet (registered trademark of Sumitomo Electric Industry Co., Ltd .: Poaflon) was used as the sheet-like porous member, and the drum was wound around the drum under the same conditions as in Example 1 except that the rotation speed of the drum was changed to 100 rpm. A 20 μm-thick film was formed by spraying an aqueous dispersion containing pseudo-bemite nanofibers on the surface of the fluororesin porous sheet that had been fixed in place to produce a sheet for a total heat exchange element.

The cross section of the film of the obtained total heat exchange element sheet was observed by TEM. As a result, the membrane was alternately laminated with pseudo-boehmite nanofiber layers (first thin layer and second thin layer) having different orientation states, and each layer had a thickness of 100 to 200 nm and a number of layers of 13. It was confirmed that it was a certain laminated film.

In the first thin layer, the orientation of the pseudo-bemite nanofibers appearing on the surface of the membrane when viewed in a plan view is random, and the pseudo-bemite nanofibers oriented parallel to the surface of the membrane account for less than 30% of the entire surface of the membrane. Met. In the first thin layer, the orientation in which the pseudo-boehmite nanofibers were parallel to the film surface and the orientation in which the pseudo-boehmite nanofibers were inclined at an angle of 0 to 15 ° were mixed when viewed in cross section.

On the other hand, when the second thin layer was viewed in a plan view, one end surface and one end portion of the pseudo-boehmite nanofiber appeared on the surface of the second thin layer. In the second thin layer, when viewed in cross section, the pseudo-boehmite nanofibers were mixed with an orientation parallel to the axis perpendicular to the film surface and an orientation inclined at an angle of 0 to 30 °.
(Comparative Example 1)
An amount of ^{20 g / m 2} of an aqueous dispersion in which pseudo-bemite nanofibers similar to those in Example 1 are dispersed on one surface of a sheet-like porous member having a thickness of 300 μm and containing alumina fibers having an average diameter of 300 μm as a main component. A sheet for a total heat exchange element was manufactured by applying a squeegee to the material and drying it.

The cross section of the obtained total heat exchange element sheet was observed by TEM. As a result, most of the pseudoboehmite nanofibers invaded a large number of pores on the surface of the sheet-shaped porous member and reached the back surface of the porous member. Therefore, it was not observed as a film, and a large number of pinholes and cracks were observed in the composite material in which pseudo-boehmite nanofibers were integrated with the porous member.
(Comparative Example 2)
An aqueous dispersion in which alumina fibers having an average fiber diameter of 1 μm are dispersed ^{is squeegee-coated at an amount of 20 g / m 2 on} one surface of a sheet-like porous member similar to Comparative Example 1, dried and dried to a thickness of 10 μm. A film was formed to manufacture a sheet for a total heat exchange element.

The cross section of the obtained total heat exchange element sheet was observed by TEM. As a result, it was confirmed that one layer of a film oriented parallel to the surface was formed on one surface of the sheet-shaped porous member. However, the alumina fiber penetrated into the pores of the porous member, and pinholes and cracks were observed in the film.

The water vapor permeation rate Vs and the water vapor separation rate α of the obtained sheets for total heat exchange elements of Examples 1 and 2 and Comparative Examples 1 and 2 were measured.

First, a flow path member having a triangular cross section is placed in contact with the membrane surface of the total heat exchange element sheet, and a plurality of first linear shapes forming a triangular prism surrounded by the film and each wave of the flow path member. A flow path was formed. Subsequently, a plurality of thirds are arranged in contact with a flow path member having a triangular cross section on the surface of the porous member of the total heat exchange element sheet, and form a triangular prism surrounded by the porous member and each wave of the flow path member. The total heat exchange cell for evaluation was assembled by forming the linear flow path of 2. The first and second linear flow paths of the total heat exchange cell face each other and are parallel to each other. Further, the pitch and height of the first and second linear flow paths are shaped to conform to the existing total heat conversion element.

The water vapor permeation rate Vs and the water vapor separation rate α of the total heat exchange cell for evaluation were measured by the following methods.

1) Method for measuring water vapor permeation velocity Vs A total heat exchange cell was installed in a constant temperature and humidity chamber, and a high humidity side duct was connected to one end of the first linear flow path thereof. The low humidity side duct was connected to one end of the second linear flow path located on the opposite side of the connection end of the high humidity side duct of the first linear flow path. A fan was installed in the high-humidity duct, and a heat exchanger was installed in the low-humidity duct.

By driving the fan, high humidity air was supplied to the first linear flow path through the high humidity duct. On the other hand, nitrogen having a dew point of −110 ° C. was supplied from the outside of the constant temperature and humidity chamber to the second linear flow path through the low humidity side duct. While the nitrogen was flowing through the low-humidity duct, heat was exchanged by a heat exchanger to make the temperature equal, and the dry nitrogen was supplied to the second linear flow path. That is, the high-humidity air and the dry nitrogen were supplied as countercurrents to the first and second linear flow paths of the total heat exchange cell, respectively. At this time, the passing wind speed in the first and second linear flow paths was set to be the same as that at the time of evaluation of the total heat exchange element.

At the outlet of the low humidity duct, the temperature, humidity, and oxygen concentration of the exhaust air were measured, and the water vapor permeation rate was calculated.

2) Water vapor separation rate α
Originally, it is necessary to grasp the permeation amount of carbon dioxide according to the JIS standard, but since the gas diffusion coefficient in nitrogen is almost the same for carbon dioxide and oxygen, oxygen from the outlet of the low humidity side duct is used in this measurement. The permeation (concentration) of CO _{2 was used} as a substitute for the permeation of CO 2, and the separation rate of water vapor was calculated.
In addition, the cell pitch and flow path height are shaped to conform to the existing total enthalpy heat exchange element so that the passing wind speed is the same as when evaluating the total enthalpy heat exchange element. High-humidity air and low-humidity air were supplied by countercurrent.

The values of the water vapor permeation rate Vs and the separation rate α in Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1 below.

As is clear from Table 1, the evaluation total heat exchange cell incorporating the total heat exchange element sheet of Examples 1 and 2 has a high water vapor permeation rate Vs of 72 g / h / m ² / kPa or more. Above, it can be seen that the separation rate α shows a much higher value than the evaluation total heat exchange cell incorporating the total heat exchange element sheet of Comparative Examples 1 and 2. From this, it can be seen that the total heat exchange element sheets of Examples 1 and 2 have higher total heat exchange efficiency than the total heat exchange element sheets of Comparative Examples 1 and 2.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Sheet for total heat exchange element, 2 ... Porous member, 3 ... Membrane, 10 ... Total heat exchange element, 21 ... First linear flow path, 22 ... Second linear flow path, 31 ... First Thin layer, 32 ... second thin layer, 100 ... total heat exchanger, 110a ... outside air, 110b ... intake, 110c ... return air, 110d ... exhaust.

Claims (8)

A film containing an inorganic fiber having a fiber diameter of 1 nm or more and 50 nm or less provided on one surface of the porous member is provided.
The film is a sheet for a total heat exchange element having a multilayer structure in which two or more thin layers having different orientation states of the inorganic fibers are laminated. The sheet for a total heat exchange element according to claim 1, wherein the porous member is mainly composed of an organic fiber having a fiber diameter of 1 μm or more and 100 μm or less. The sheet for a total heat exchange element according to claim 1 or 2, wherein the inorganic fiber has hydrophilicity. The sheet for a total heat exchange element according to any one of claims 1 to 3, wherein the inorganic fiber contains at least one selected from the group consisting of boehmite and pseudo-boehmite. In thin layers in which the orientation state of the inorganic fibers is different,
In the first thin layer, the orientation of the inorganic fibers is random when the thin layer is viewed in a plan view, and the inorganic fibers are parallel and / or inclined with respect to the surface of the thin layer when the thin layer is viewed in cross section. Oriented,
In the second thin layer, one end surface and / or one end portion of the inorganic fiber appears when the thin layer is viewed in a plan view, and the axis of the inorganic fiber perpendicular to the surface of the thin layer when the thin layer is viewed in cross section. The sheet for a total heat exchange element according to any one of claims 1 to 4, which is oriented parallel to and / or inclined with respect to the surface. The sheet for a total heat exchange element according to any one of claims 1 to 5, wherein the first and second thin layers have a thickness of 300 nm or less. A total heat exchange element including the sheet for the total heat exchange element according to any one of claims 1 to 6. A total heat exchanger comprising the total heat exchange element according to claim 7.

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