JP2020038022A - Sheet for total heat exchange element, total heat exchange element, total heat exchanger, and steam separation body - Google Patents

Abstract

To provide a sheet for a total heat exchange element, a total heat exchange element, a total heat exchanger, and a steam separation body that have improved a separation ratio of steam and gas other than steam while maintaining a high water vapor permeation speed.SOLUTION: A sheet for a total heat exchange element includes: a porous member including an organic fiber and having an opening of 10 μm to 1 mm in diameter on one surface; and a membrane including an inorganic fiber provided on one surface of the porous member. A fiber with an average fiber diameter of 100 nm to 5 μm, and an average fiber length of 0.35-5 mm is interposed on the boundary surface of the porous member and the membrane.SELECTED DRAWING: Figure 5

Description

  Embodiments relate to a sheet for a total heat exchange element, a total heat exchange element, a total heat exchanger, and a steam separator.

  2. Description of the Related Art In recent years, reduction of energy consumption has been demanded from the viewpoint 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 is a problem. The total heat exchanger, one of the air conditioners, exchanges total heat (sensible heat (temperature) and latent heat (humidity)) between temperature- and humidity-controlled air inside the building and outside air. This is a device that suppresses heat loss and saves energy.

  The conventional total heat exchange element uses a sheet for a 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 element sheet has a low total heat exchange efficiency of about 70%. By replacing the sheet for total heat exchange elements with a material having a higher exchange efficiency, a total heat exchanger with further energy saving can be realized.

JP-B-61-058759 JP-A-2004-154457 JP 2010-234213 A

  The problem to be solved by the present invention is a sheet for a total heat exchange element, a total heat exchange element, a total heat exchanger, which has an improved separation ratio between water vapor and a gas excluding water vapor while maintaining a high water vapor transmission rate. Provide a steam separator.

  The sheet for a total heat exchange element according to the embodiment includes an organic fiber, a porous member having an opening having a hole diameter of 10 μm or more and 1 mm or less on one surface, and an inorganic fiber provided on one surface of the porous member. And a film containing: Fibers having an average fiber diameter of 100 nm or more and 5 μm or less and an average fiber length of 0.35 mm or more and 5 mm or less exist at the interface between the porous member and the membrane.

It is a cross section showing the sheet for total heat exchange elements concerning an embodiment. FIG. 2 is a schematic cross-sectional view in which the flow of outside air and return air to the sheet for a total heat exchange element according to the embodiment is different from that in FIG. 1. It is the cross-sectional schematic diagram which expanded the sheet | seat for total heat exchange elements of FIG. FIG. 2 is a plan view schematically showing an SEM photograph of one surface of the porous member of FIG. 1. FIG. 2 is a plan view schematically showing an SEM photograph taken from a fiber region of the sheet for a total heat exchange element sheet of FIG. 1 from which a film is removed toward a porous member. It is a perspective view showing the total heat exchange element concerning an embodiment. It is a schematic diagram showing a total heat exchanger concerning an embodiment for explaining total heat exchange in summer. It is a schematic diagram showing a total heat exchanger concerning an embodiment for explaining total heat exchange in winter.

  Hereinafter, embodiments will be described with reference to the drawings. In each embodiment, substantially the same components are denoted 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 dimension, the ratio of the thickness of each part, and the like may be different from the actual one. The terms indicating directions such as up and down in the description may be different from the actual directions based on the direction of gravitational acceleration.

  FIG. 1 is a schematic cross-sectional view showing a sheet for a total heat exchange element according to an embodiment, and FIG. 2 is a schematic cross-sectional view in which flows of outside air and return air to the sheet for a total heat exchange element according to the embodiment are different from those in FIG. FIG. 3 is an enlarged schematic sectional view of the sheet for total heat exchange element of FIG.

  The sheet 1 for a total heat exchange element includes a porous member 2 and a film 4 provided on one surface of the porous member 2 as shown in FIGS. The fiber region 3 exists at the interface. Such a laminate of the porous member 2, the fiber region 3, and the membrane 4 has a function as a water vapor separator.

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

  For example, when the outside air 110a is hotter and humid than the return air 110c, as shown in FIG. 1, the outside air 110a mainly circulates along the flow path (not shown) on the surface 41 of the membrane 4 and becomes the indoor air as the intake air 110b. The return air 110c mainly passes through the surface 21 of the porous member 2 along a flow path (not shown) and is discharged outside as an exhaust 110d. The outside air 110a and the return air 110c are circulated, for example, so as to face each other. However, the outside air 110a and the return air 110c may cross each other at an angle depending on the design of total heat exchange. In this way, the outside air 110a is caused to flow along the surface 41 of the membrane 4 of the sheet for total heat exchange elements 1 and the return air 110c along the surface 21 of the porous member 2 of the sheet 1 for total heat exchange elements. The water vapor and heat contained in the gas pass through the sheet for total heat exchange element 1 and move to the return air 110c side adjusted to low humidity and low temperature.

  On the other hand, when the outside air 110a is lower in temperature and humidity than the return air 110c, the return air 110c mainly passes through the surface 41 of the membrane 4 along the flow path (not shown) as the exhaust 110d as shown in FIG. The outside air 110a is discharged outside the room, passes mainly along the surface 21 of the porous member 2 along a flow path (not shown), and is discharged into the room as intake air 110b. The return air 110c and the outside air 110a are circulated so as to face each other. By returning the return air 110c along the surface 41 of the membrane 4 of the sheet for total heat exchange elements 1 and the outside air 110a along the surface 21 of the porous member 2 of the sheet 1 for total heat exchange elements, the return air Water vapor and heat (sensible heat and latent heat) contained in 110c 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.

  The outside air and the return air pass through the surface 41 of the membrane 4 of the sheet for total heat exchange element 1 and the surface 21 of the porous member 2 along the flow path so that they do not come into contact with each other, so that water vapor and other gases are efficiently exchanged. Separation is preferred. Therefore, the sheet for total heat exchange elements 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 transmission rate Vs and the separation rate α indicating the ability to separate water vapor and a gas other than water vapor (such as air) be high.

The water vapor transmission rate Vs of the sheet for total heat exchange element 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 transmission rate Vs of the sheet for the total heat exchange element is represented by the following equation (1). If the water vapor transmission rate Vs of the sheet for total heat exchange elements 1 is low, the efficiency of humidity exchange is reduced, and there is a possibility that the loss as a total heat exchanger increases.

Water vapor transmission rate Vs (g / h / m ² / kPa) of sheet 1 for total heat exchange element = (moisture amount (g) permeated through sheet 1 for total heat exchange element) / (sheet 1 for total heat exchange element) Time (h) permeated by water / (area (m ² ) of total heat exchange element sheet 1) / (water vapor pressure difference (kPa) on both surfaces of total heat exchange element sheet 1) (1)
It is required that the separation rate α of water vapor and gas excluding water vapor of the sheet for total heat exchange element 1 be 10 or more, 20 or more, and 50 or more. The separation rate α is represented by the following equation (2).

α = [(moles of water permeated through sheet for total heat exchange element 1) / (moles of dry air of exhaust 7d)] / [(moles of water of outside air 7a) / (moles of dry air of outside air 7a) Moles)] (2)
If the separation rate α is too low, it becomes difficult to separate the water vapor from the gas other than the 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-described porous member 2, fiber region 3, and membrane 4 will be described in detail below.
<Porous member 2>
The porous member 2 contains an organic fiber. Organic fibers are preferred because of their high flexibility and low cost.

  FIG. 4 is a plan view schematically showing an SEM photograph of one surface of the porous member of the sheet for a total heat exchange element. As shown in FIG. 4, the porous member 2 includes an organic fiber 2a, and has an opening 2b having a hole diameter of 10 μm or more and 1 mm or less on one surface. Here, when the shape of the hole is an ellipse or a polygon, the “hole diameter” is imagined as a perfect circle surrounding the ellipse or the polygon, and the diameter of the virtual perfect circle is defined as the hole diameter.

  If the hole diameter is less than 10 μm, the water vapor transmission rate Vs of the sheet for all heat exchange elements may decrease. On the other hand, when the pore diameter exceeds 1 mm, even when fibers described later are present on one surface of the porous member 2, when forming the film 4 on one surface of the porous member 2, the film 4 It is easy to penetrate into the opening of No. 2 and pinholes and cracks may be generated, which may lower the performance of separating water vapor and a gas other than water vapor (for example, air). The preferred diameter of the opening 2b is 10 μm or more and 200 μm or less.

  It is preferable that the openings 2 b be present in an area ratio of 10% or more and 90% or less with respect to one surface of the porous member 2.

  The organic fibers 2a contained in the porous member 2 preferably have an average fiber diameter of 1 μm or more and 100 μm or less. It is desirable that such organic fibers 2a contain 50% by weight or more, more preferably more than 75% by weight, and even more preferably more than 90% by weight with respect to the constituent material of the porous member 2. Even if the organic fiber 2a is a single kind of organic fiber, a plurality of kinds of organic fiber porous members 2 may have, in addition to the organic fiber, an additive, for example, a polymer component for adjusting a gap between the organic fibers. May be contained, and ceramic particles such as a hygroscopic agent or an oxide may be included in order to provide the porous member 2 with flame retardancy. Further, it may contain a treating agent for adjusting water repellency and water resistance and an organic component. It is preferable that the additive contains 0.1 to 10% by weight based on the constituent material of the porous member 2.

  As the organic fibers 2a, for example, synthetic fibers, natural fibers, or the like can be used. The natural fiber contains, for example, cellulose as a main component. The organic fibers may be flat in the radial direction. Further, the organic fibers may be hollow fibers.

  The porous member 2 may be, for example, a nonwoven fabric, paper, an organic porous material, or a molded product (including paper) made of synthetic fiber or natural fiber. The organic fibers 2a included in the porous member 2 may be an aggregate of organic nanofibers having a size of submicron or less. By using the aggregate of the organic nanofibers, the bonding force between the porous member 2 and the fibers 3a existing on one surface of the porous member 2 is increased, and as a result, the membrane 4 is separated from the porous member 2. Can be prevented.

  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 500 μm or less. If the porous member 2 is too thin, deformation such as bending occurs during handling, and not only a defect such as a crack occurs in the film 4 provided on one surface of the porous member 2 where fibers exist, but also a breakage. There is a risk of doing so. If the porous member 2 is too thick, not only does the water vapor transmission rate Vs decrease, but also the heat conduction decreases, so that the total heat exchange efficiency may decrease.

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 increases, and the efficiency of exchanging total heat may decrease.

  The volume porosity (volume ratio of pores) of the porous member 2 is preferably 20% or more and 80% or less, 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 will increase, and the total heat exchange efficiency may decrease. If the volume porosity of the porous member 2 exceeds 80%, the strength of the porous member 2 decreases, and cracks occur in the film 4 provided on one surface of the porous member 2 in which fibers exist, which will be described later. There is a possibility that the formation of a wet seal may be hindered. In addition, the opening and volume porosity of the porous member 2 can be measured by a mercury intrusion method.

The water vapor transmission 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 transmission rate Vs of the porous member 2 is represented by the following equation (3).

Water vapor transmission rate Vs of porous member 2 (g / h / m ² / kPa) = (moisture amount permeating through porous member 2 (g)) / (time (h) during which moisture permeates porous member 2) / (Area (m ² ) of porous member 2) / (water vapor pressure difference (kPa) on both surfaces of porous member 2) (3)
If the water vapor transmission rate Vs of the porous member 2 determined by the above equation (3) is too low, the water vapor transmission rate Vs of the entire heat exchange element sheet decreases, and the total heat exchange efficiency may decrease.
<Fiber region 3>
The fiber region 3 contains fibers existing at the interface between the porous member 2 and the membrane 4. FIG. 5 is a plan view schematically showing an SEM photograph taken from the fiber region 3 of the total heat exchange element sheet 1 from which the membrane 4 has been removed toward the porous member 2. As shown in FIG. 5, the fiber region 3 includes a fiber 3a having an average fiber diameter of 100 nm or more and 5 μm or less and an average fiber length of 0.35 mm or more and 5 mm or less present on one surface of the porous member 2. Reference numeral 3a partially covers the opening 2b (having a diameter of 10 μm or more and 1 mm or less) on one surface of the porous member 2.

  When the fibers 3a are present at the interface between the porous member 2 and the membrane 4 (one surface of the porous member 2), the average fiber diameter and average fiber of the fibers 3a with respect to the opening size of the openings 2b of the porous member 2 By defining the length in the above range and optimizing the length, the fiber 3a partially covers the opening 2b of the porous member 2 as shown in FIG. That is, the fiber 3a reduces the size of the opening 2b of the porous member 2, and when a film 4 is further provided on one surface of the porous member 2 where the fiber 3a is present, the film component enters the opening 2b. Can be suppressed or prevented.

  The fibers 3a preferably account for 0.1% by weight or more and 5% by weight or less based on the total heat exchange element sheet.

The fibers 3a are preferably polymer fibers. The polymer fiber is not particularly limited. For example, cellulose, a natural polymer such as protein, polyethylene, polypropylene, vinyl chloride, polystyrene, polyvinyl acetate, polyurethane, acrylonitrile-butadiene-styrene copolymer resin (ABS resin) And synthetic polymers such as acrylonitrile / styrene copolymer resin (AS resin), acrylic resin, polyamide, polyacetal, polycarbonate, polyester, polyphenylene sulfide, liquid crystal polymer, polyetheretherketone, polyimide, and aramid. .
<Membrane 4>
The membrane 4 is provided on one surface of the porous member 2 where the fibers 3a are present, and includes inorganic fibers. The inorganic fibers preferably have an average fiber diameter of 1 nm or more and 50 nm or less. Inorganic fibers are preferred because of their high heat resistance. Inorganic fibers having a hydrophilic group, for example, an OH group, are preferable because water vapor is easily adsorbed.

  When the membrane 4 contains inorganic fibers having an average fiber diameter of 1 nm or more and 50 nm or less, the inorganic fibers preferably contain 80% by weight or more, more preferably 90% by weight or more of the constituent materials of the membrane. The inorganic fiber may be a single type of inorganic fiber or a plurality of types of inorganic fibers.

  The average fiber length of the inorganic fibers is preferably 0.5 μm or more and 15 μm or less. The average fiber length of the inorganic fibers is more preferably 1 μm or more and 3 μm or less. When the average fiber length is shorter than 0.5 μm, the force at which the fibers are entangled with each other is small, and there is a possibility that cracks are likely to occur when forming a film. When the average fiber length is longer than 15 μm, the aspect ratio with respect to the fiber diameter becomes too large, and the fiber is easily broken.

  The inorganic fiber is not particularly limited, but is preferably a hydrophilic material. The hydrophilic material is, for example, at least one selected from the group consisting of 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) A carbonate containing at least one selected from the group consisting of: a phosphate containing at least one selected from the group consisting of Mg, Ca, and Sr; a phosphate containing at least one selected from the group consisting of Mg, Ca, Sr, and Al Titanate; or a composite or a mixture thereof can be used. Alternatively, a metal compound formed by using a metal hydroxide as a precursor, binding the precursor by hydrolysis or the like, stopping the reaction halfway, and controlling the number of OH groups may be used.

  Specific hydrophilic inorganic fibers include, for example, alumina (including boehmite or pseudo-boehmite), silica, titania, zirconia, magnesia, zinc oxide, ferrite, zeolite, hydroxyapatite, barium titanate, and hydrates thereof. But not limited thereto.

  It is particularly preferred that the inorganic fibers include boehmite or pseudo-boehmite. Pseudo-boehmite is a material containing alumina hydrate whose crystal structure is partially different from that of boehmite. Boehmite and pseudo-boehmite have a large amount of OH groups between the surface and the layers of crystals, and therefore easily adsorb water vapor, which is advantageous for forming a wet seal.

  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, a sheet-like porous member having an opening with a hole diameter of 10 μm or more and 1 mm or less on one surface is prepared.

  2) The sheet-shaped porous member is wound and fixed on a rotatable drum surface having a desired diameter such that one surface thereof is located outside.

  3) Dispose the tip of the nozzle opposite the drum. The nozzle reciprocates in the width direction of the porous member wound around the drum.

  4) While the drum is rotating, the nozzle reciprocates in the width direction of the porous member, during which an aqueous dispersion containing fibers having an average fiber diameter of 100 nm to 5 μm and an average fiber length of 0.35 mm to 5 mm from the nozzle. The liquid is sprayed at a desired speed toward one surface (surface) of the sheet-like porous member. Then, by drying, a fiber region containing fibers is formed on one surface of the porous member.

  5) While rotating the drum again, the nozzle is reciprocated in the width direction of the porous member, and during this time, an aqueous dispersion containing inorganic fibers is sprayed from the nozzle onto one surface of the porous member in which the fibers are present. Thereafter, by drying, a film having a desired thickness is formed on one surface of the porous member on which the fibers formed in the step 4) are present, to manufacture a sheet for a total heat exchange element.

  After the fibers are present on one surface of the porous member in the step 4), when the fine structure is observed with a scanning electron microscope from the fiber side toward the porous member, the schematic diagram of FIG. 5 described above is obtained. Can be confirmed.

  According to the embodiment described above, the pore diameter of the porous member is 10 μm or more and 1 mm or less The pinhole on one surface having a hole, the generation of cracks is suppressed or prevented, a thin and dense film containing inorganic fibers is formed. Can be provided. As a result, the porous member 2 on which the membrane is to be formed has openings on one surface, and is arranged on one surface of the porous member while maintaining a high water vapor transmission rate by the porous member having high air permeability. Further, it is possible to provide a sheet for a total heat exchange element in which the separation rate of water vapor and a gas other than water vapor (for example, air) is improved by a dense film in which pinholes and cracks are suppressed or prevented from occurring.

  That is, when a thin and dense membrane is directly provided on one surface of a porous member having a pore size of 10 μm or more and 1 mm or less and having high air permeability, a membrane component enters the pores of the porous member. As a result, not only do the pores of the porous member be filled to lower the water vapor transmission rate, but also pinholes and cracks occur in the film formed on one surface of the porous member. When pinholes and cracks occur in the membrane provided on one surface of the porous member, the water vapor separation rate of the membrane rapidly decreases and high exchange efficiency cannot be obtained.

  For this reason, in the embodiment, the average fiber diameter is 100 nm or more and 5 μm or less on one surface (the interface between the porous member and the membrane) of the porous member 2 having the openings 2 a having a hole diameter of 10 μm or more and 1 mm or less. The fibers 3a having a length of 0.35 mm or more and 5 mm or less exist. When such fibers 3a are present on one surface of the porous member 2, the average fiber diameter and average fiber length of the fibers 3a with respect to the size of the openings 2b of the porous member 2 including the organic fibers 2a are defined in the above ranges. Then, by optimizing, as shown in FIG. 5, the fiber 3a partially covers the opening 2b of the porous member 2, and the diameter of the opening can be substantially reduced. That is, the fiber 3a reduces the exposed area of the opening 2b of the porous member 2, and when the film 4 is provided on one surface of the porous member 2 where the fiber 3a exists, the film component is transferred to the opening 2b. Intrusion can be suppressed or prevented. As a result, even if the thickness of the membrane 4 is reduced, the dense membrane 4 in which the generation of pinholes and cracks is suppressed or prevented can be provided on one surface of the porous member 2 where the fibers 3a exist.

  Therefore, while maintaining the air permeability of the porous member 2, a dense membrane can be provided on the porous member with a small amount of membrane components, and the sheet for a total heat exchange element having a high separation rate and a high water vapor transmission rate. Can be provided.

  Further, the film 4 provided on one surface of the porous member 2 in which the fibers 3a are present is a thin and dense film that suppresses or prevents the occurrence of pinholes and cracks. For this reason, a decrease in the water vapor separation rate of the membrane due to pinholes and cracks can be suppressed. In addition, since fine pores can be formed between the inorganic fibers of the membrane 4, water vapor contained in the outside air or the like is condensed by Kelvin's capillary condensation theory and filled in the pores to form a wet seal. The wet seal adsorbs water vapor contained in the outside air or the like, and can smoothly move from the membrane 4 to the porous member 2. That is, since the interface between the membrane 4 and one surface of the porous member 2 is not a layer but the fibers 3a are present, the water vapor is smoothly and quickly moved from the membrane 4 to the porous member 2 without hindering the movement. be able to. The wet seal can suppress the permeation of gas (for example, air) excluding water vapor. From these effects, a sheet for a total heat exchange element having a higher water vapor separation rate can be provided.

  In the embodiment, by using inorganic fibers having an average fiber diameter of 1 nm or more and 50 nm or less as the inorganic fibers contained in the dense film 4, more fine pores can be formed between the inorganic fibers, and a wet seal is formed on the film 4. More can be formed. As a result, the adsorbability of water vapor contained in the outside air or the like flowing in contact with the surface of the membrane 4 is improved, and the water vapor can be moved from the membrane 4 to the porous member 2, that is, the water vapor transmission rate can be further increased. Further, by increasing the wet seal, the permeation of gas excluding water vapor can be effectively suppressed, that is, the separation rate between water vapor and gas excluding water vapor can be further increased.

  Since the sheet for a total heat exchange element according to the embodiment has the above-described excellent functions, it can be used as a water vapor separator.

  Further, the sheet for a total heat exchange element according to the embodiment can be applied to other than the total heat exchange element. For example, it can be used for a dehumidifying sheet, a filter, a humidity control element, and the like. Specific applications include a dehumidifying rotor element, an air-conditioning vaporizing humidifying element, a humidifying element for a fuel cell, a dehumidifying element for a dehumidifier, a water absorption and evaporation element for a vending machine, a water absorption and evaporation element for cooling, and a desiccant air conditioner. Examples include a rotor element and a vehicle air conditioner.

  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. 6 is a perspective view showing the total heat exchange element according to the embodiment. The total heat exchange element 10 includes a plurality of, for example, six sheets of the total heat exchange element sheet 1 described above, two sheets (arranged in the lowermost layer and the uppermost layer) of reinforcing sheets 12a and 12b, and a plurality of sheets (for example, (Seven sheets) of cross-sectional waveforms, for example, a channel member 13 having a triangular waveform in cross section.

  The sheets for total heat exchange elements 1 are stacked at a constant interval from each other such that the film 4 is located on the lower surface. The reinforcing sheets 12a and 12b are arranged on the uppermost layer and the lowermost layer of the laminate at a fixed distance from the total heat exchange element sheet 1. The channel member 13 having a triangular waveform in cross section is interposed and fixed between the reinforcing sheet 12a, the six total heat exchange element sheets 1 and the reinforcing sheet 12b alternately at an angle of, for example, 90 °. . The flow path member 13 is not particularly limited. For example, the flow path member 13 can be made of a paper sheet mainly composed of pulp processed into a corrugated form, a general-purpose resin such as polyvinyl chloride or polypropylene, or a metal such as stainless steel. The first straight flow path 51 is formed so as to be surrounded by the membrane 4 of the sheet for total heat exchange elements 1 and the cross-sectional triangular wave of the flow path member 13 having a triangular cross-section. The second straight flow path 52 is formed so as to be surrounded by the porous member 2 of the total heat exchange element sheet 1 and the triangular wave cross section of the flow path member 13 having a triangular cross section. The first and second linear flow paths 51 and 52 are arranged so as to intersect 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-described total heat exchange element. FIG. 7 is a schematic diagram illustrating a total heat exchanger according to an embodiment for explaining total heat exchange in summer. That is, the total heat exchanger 100 includes the housing 101. In the housing 101, the above-described total heat exchange element 10 shown in FIG.

  Inside the housing 101, first to fourth compartments 104 a to 104 d 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, respectively. The first to fourth compartments 104a to 104d are arranged at the upper left, upper right, lower left, and lower right of the housing 101, respectively.

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

The total heat exchanger 100 provided with such a total heat exchange element 10 performs total heat exchange by the following operation.
<Total heat exchange in hot and humid summer season>
By driving the second fan 107b, the outside air (hotter and humid than the return air) 110a indicated by an arrow from outside the room is passed through the fourth opening 106d and the fourth compartment 104d. The first heat exchange element sheet 1 shown in FIG. 1 circulates in a straight flow path (not shown) in contact with the surface 41 of the membrane 4, and further flows into the first compartment 104 a and the first opening. The air is introduced into the room through an air inlet 110b indicated by an arrow through the air inlet 106a. At the same time, by driving the first fan 107a, the return air 110c indicated by the arrow from the room is passed through the third opening 106c and the third compartment 104c to the plurality of second linear flows of the total heat exchange element 10. In the passage (not shown), the sheet flows through the surface 21 of the porous member 2 of the sheet for total heat exchange element 1 shown in FIG. 1 and further flows through the second compartment 104b and the second opening 106b. Is discharged outside as an exhaust 110d shown in FIG.

In such a total heat exchange element 10, the outside air 110a is introduced into a first linear flow path (not shown) of the total heat exchange element 10, and the membrane 4 of the sheet 1 for a total heat exchange element shown in FIG. The return air 110c is introduced into a second linear flow path (not shown) intersecting the first linear flow path with the total heat exchange element sheet 1 interposed therebetween. 1 is circulated in contact with the surface 21 of the porous member 2 of the sheet for total heat exchange element 1 shown in FIG. At this time, since the outside air 110a has a higher temperature and a higher humidity than the return air 110c, the steam and heat contained in the outside air 110a in the total heat exchange element 10 are moved to the return air 110c 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. 7, in the winter, the total heat exchange can be performed 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 path of the outside air and the return air, and the direction of the air supply by the first and second fans may be switched as shown in FIG. FIG. 8 is a schematic diagram illustrating 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 an arrow from the room flows through the first opening 106a and the first compartment 104a into the plurality of first linear flows of the total heat exchange element 10. It flows in a path (not shown) in contact with the surface 41 of the membrane 4 of the sheet for total heat exchange element 1 shown in FIG. 1, and furthermore, is indicated by an arrow through a fourth compartment 104d and a fourth opening 106d. It is exhausted outside as an exhaust 110d. 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 an arrow from the outside is passed through the second opening 106b and the second compartment 104b to the third heat exchange element 10a. 2, flows in contact with the surface 21 of the porous member 2 in a linear flow path (not shown), and flows through the third compartment 104 c and the third opening 106 c as air intake 110 b indicated by an arrow into the room. be introduced.

  In such a total heat exchange element 10, the return air 110c is introduced into a first linear flow path (not shown) and comes into contact with the surface 31 of the membrane 3 of the sheet 1 for a total heat exchange element shown in FIG. The outside air 110a is introduced into a second linear flow path (not shown) intersecting the first linear flow path with the total heat exchange element sheet 1 interposed therebetween, and the whole air shown in FIG. It is circulated in contact with the surface 21 of the porous member 2 of the heat exchange element sheet 1. At this time, since the outside air 110a has a lower temperature and a lower humidity than the return air 110c, the steam and heat contained in the return air 110c in the total heat exchange element 10 are moved to the outside air 110a through the total heat exchange element sheet 1.

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

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

Hereinafter, embodiments will be described in detail.
(Example 1)
First, a 200-μm-thick sheet-like porous member made of pulp having an average diameter of 50 μm was prepared. One surface of the porous member had a substantially triangular opening having a hole diameter of 10 to 50 μm. The sheet-like porous member was wound and fixed on a rotatable drum surface having a diameter of 20 cm so that one surface thereof was located outside. The tip of the nozzle was arranged to face 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 reciprocates at a speed of 5 cm / min in the width direction of the porous member, and during this time, a cellulose fiber having an average diameter of 500 nm and an average length of 0.5 mm is output from the nozzle. The aqueous dispersion containing the nanofibers was sprayed toward one surface of the porous member and dried to allow the cellulose nanofibers to be present on one surface of the porous member. While rotating the drum again at the same speed, the nozzle reciprocates in the width direction of the porous member at a speed of 5 cm / min, during which an aqueous system containing pseudo-boehmite nanofibers having an average diameter of 4 nm and an average length of 1 μm from the nozzle. The dispersion was sprayed toward one surface of the porous member on which the cellulose nanofibers were present. Thereafter, by drying, a film having a thickness of 10 μm was formed on one surface of the porous member on which the cellulose nanofibers were present, to produce a sheet for a total heat exchange element.
(Comparative Example 1)
A total heat exchange element was manufactured in the same manner as in Example 1, except that the cellulose nanofiber was not present on one surface of the sheet-like porous member as in Example 1, and a film of pseudo-boehmite nanofiber was formed directly. Sheet was manufactured.
(Comparative Example 2)
A sheet for a total heat exchange element was manufactured in the same manner as in Example 1, except that cellulose nanofiber having an average fiber diameter of 10 nm and an average fiber length of 2 μm was used as the polymer fiber to be present on one surface of the porous member. did.
(Comparative Example 3)
A sheet for a total heat exchange element was manufactured in the same manner as in Example 1, except that a cellulose nanofiber having an average fiber diameter of 20 μm and an average fiber length of 1 cm was used as a polymer fiber to be present on one surface of the porous member. did.

  The water vapor transmission rate Vs and the water vapor separation rate α of the obtained sheets for a total heat exchange element of Example 1 and Comparative Examples 1 to 3 were measured.

  First, a flow path member having a triangular waveform in section is disposed in contact with the membrane surface of the sheet for a total heat exchange element, and a plurality of first linear shapes forming a triangular prism surrounded by the membrane and each wave of the flow path member. A channel was formed. Subsequently, a flow path member having a triangular waveform in cross section is disposed in contact with the surface of the porous member of the sheet for total heat exchange element, and a plurality of first triangular prisms surrounded by the respective waves of the porous member and the flow path member are formed. An evaluation total heat exchange cell was assembled by forming two straight flow paths. The first and second straight 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 were formed in a shape conforming to the existing total heat conversion element.

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

1) Measurement method of water vapor transmission rate Vs The total heat exchange cell was installed in a thermo-hygrostat, and a high-humidity side duct was connected to one end of the first linear flow path. The low humidity side duct was connected to one end of the second linear flow path located on the side opposite to the connection end of the high humidity side duct of the first linear flow path. A fan was interposed in the high humidity side duct, and a heat exchanger was interposed in the low humidity side duct.

  By driving the fan, high-humidity air was supplied to the first straight channel through the high-humidity duct. On the other hand, nitrogen having a dew point of -110 ° C was supplied from the outside of the thermo-hygrostat to the second straight channel through the low humidity side duct. While the nitrogen was flowing through the low-humidity side duct, heat was exchanged in a heat exchanger to make it isothermal and dry nitrogen was supplied to the second straight flow path. That is, the humid air and the dry nitrogen were supplied to the first and second linear flow paths of the total heat exchange cell, respectively, as opposed flows. At this time, the wind velocities passing through the first and second straight flow paths were set to be the same as those 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 transmission rate was calculated.

2) Separation rate of water vapor α
Originally, it is necessary to grasp the permeation amount of carbon dioxide according to the JIS standard. However, since carbon dioxide and oxygen have almost the same gas diffusion coefficient in nitrogen, in this measurement oxygen from the outlet of the low humidity side duct was measured. The permeation (concentration) of CO _{2 was used} as a substitute for CO ₂ permeation, and the water vapor separation rate was calculated.

  The pitch of the cells and the height of the flow path were made to conform to those of the existing total heat exchange element, and the passing wind velocity was the same as that at the time of evaluation of the total heat exchange element. High humidity air and low humidity air were supplied in countercurrent.

  Further, the water vapor transmission rate Vs-sub was also measured for the sheets for all heat exchange elements of Example 1 and Comparative Examples 1 to 3 themselves.

  The results 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 Example 1 maintains a high water vapor transmission rate Vs of 90 g / h / m ² / kPa or higher. However, it can be seen that the separation rate α also shows a high value.

  On the other hand, a total heat exchange cell for evaluation incorporating the sheet for a total heat exchange element of Comparative Example 1 in which no organic fibers are present on one surface of the porous member, and an organic fiber present on one surface of the porous member The total heat exchange cell for evaluation incorporating the sheet for a total heat exchange element of Comparative Example 3 using a thick fiber having an average fiber diameter exceeding 5 μm as an example, although the water vapor transmission rate Vs does not decrease, but the pin is attached to the membrane containing the boehmite fiber. It can be seen that since a continuous film is not formed due to generation of holes and cracks, the water vapor separation rate α is low.

  Further, the sheet for a total heat exchange element of Comparative Example 2 in which a thin and short fiber having an average fiber diameter of less than 100 nm and an average fiber length of less than 0.35 mm was used as the organic fiber to be present on one surface of the porous member was incorporated. In the total heat exchange cell for evaluation, the pores on one surface of the porous member are filled with short fibers, so that the water vapor transmission rate sharply decreases.

  Accordingly, it can be seen that the sheet for a total heat exchange element of Example 1 has a higher total heat exchange efficiency than the sheets for a total heat exchange element of Comparative Examples 1 to 3.

  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 other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

  DESCRIPTION OF SYMBOLS 1 ... Sheet for total heat exchange elements, 2 ... Porous member, 2a ... Organic fiber, 2b ... Opening, 3 ... Fiber area, 3a ... Fiber, 4 ... Membrane, 10 ... Total heat exchange element, 51 ... First Linear flow path, 52: second linear flow path, 100: total heat exchanger, 110a: outside air, 110b: intake air, 110c: return air, 110d: exhaust gas.

Claims (7)

For a total heat exchange element, comprising a porous member containing organic fibers and having an opening having a pore size of 10 μm or more and 1 mm or less on one surface, and a membrane containing inorganic fibers provided on one surface of the porous member. A sheet,
A sheet for a total heat exchange element, wherein fibers having an average fiber diameter of 100 nm or more and 5 μm or less and an average fiber length of 0.35 mm or more and 5 mm or less are present at the interface between the porous member and the membrane.   2. The sheet for a total heat exchange element according to claim 1, wherein the organic fibers of the porous member have an average fiber diameter of 1 μm or more and 100 μm or less.   The sheet for a total heat exchange element according to claim 1, wherein the fiber is a polymer fiber.   The sheet for a total heat exchange element according to any one of claims 1 to 3, wherein the inorganic fibers of the membrane include boehmite or pseudo-boehmite.   A total heat exchange element comprising the sheet for a total heat exchange element according to claim 1.   A total heat exchanger incorporating the total heat exchange element according to claim 5. A water vapor separator comprising an organic fiber, a porous member having an opening having a pore size of 10 μm or more and 1 mm or less on one surface, and a membrane containing inorganic fibers provided on one surface of the porous member. hand,
A fiber having an average fiber diameter of 100 nm or more and 5 μm or less and an average fiber length of 0.35 mm or more and 5 mm or less is a water vapor separator existing at the interface between the porous member and the membrane.

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