JPH0425476B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] This invention relates to a ventilation system that simultaneously supplies fresh outside air and exhausts contaminated air, or a fresh air treatment system for an air conditioning machine room in a building (total heat exchange between outside air and indoor air). The present invention relates to a total heat exchanger for use in, for example, a total heat exchanger that has been improved to withstand use in environments where condensation is likely to occur, particularly in cold regions. [Prior Art] In recent years, as living spaces have become more insulated and airtight in order to improve heating and cooling effects, the importance of ventilation has been reaffirmed. An effective method for ventilation without impairing the heating and cooling effect is to exchange heat between exhaust air and supply air. At this time, if both temperature (sensible heat) and humidity (latent heat) can be exchanged at the same time, the effect will be significant. To meet this demand, there has been a static total heat exchanger (Japanese Patent No. 930986) that exchanges total heat between supply air and exhaust air via a partition plate, as shown in the drawing. As shown in the drawing, this static total heat exchanger is constructed by alternately stacking flat partition plates 1 and corrugated spacing plates 2, and by making the direction of the spacing plates orthogonal to each other every other layer, the supply air flow is improved. A passage 3 and an exhaust passage 4 are formed. Note that arrows A and B indicate the directions of air supply and exhaust, respectively. For example, if fresh, cold, dry air from outside in winter is passed through as supply air, and dirty, warm, and humid air from inside a heated space is passed through as exhaust air, the temperature will be changed through the above-mentioned partition plate. Humidity exchange takes place, and the supply air is warmed, humidified, and supplied into the room. Meanwhile, the exhaust air is cooled, dehumidified, and discharged outdoors. Conventionally, processed paper treated with a hydrophilic polymer containing a moisture absorbent has been used for the partition plate, which isolates supply air and exhaust air and exhibits high total heat exchange efficiency. With the spread of total heat exchangers, there has been an increasing demand for installation in cold regions and heated pools, etc. However, due to the large temperature difference between supply air and exhaust air, condensation occurs, and the above-mentioned processed paper has problems with long-term deformation. The problem arose that it was unusable. Therefore, the inventors of the present invention have conducted extensive research in order to develop a total heat exchanger that does not deform even when condensed and can withstand long-term use. First, we focused on a porous polymer sheet with excellent water resistance and considered its application to partition plates. However, although it has excellent temperature and humidity exchange efficiency, we found that supply air and exhaust air mix through the partition plate. Ta. Therefore, as a result of repeated research to suppress the mixing of supply air and exhaust air through the partition plate while maintaining the high temperature and humidity exchange characteristics of the above-mentioned porous polymer sheet, we found that
By impregnating or coating the above-mentioned porous polymer sheet with a hydrophilic polymer containing a moisture absorbent or a cationic polymer electrolyte, water vapor can pass through it, but
They discovered that it was possible to obtain a moisture-permeable gas shield that does not allow air to pass through, and that by using the moisture-permeable gas shield as a partition plate, a total heat exchanger with excellent condensation resistance could be realized, and this invention was completed. I ended up letting it happen. [Summary of the Invention] The present invention allows two types of airflow to flow through a partition plate, and exchanges sensible heat and latent heat of the two types of airflow through the partition plate, in which the partition plate is used to absorb moisture. By being constructed with a moisture-permeable gas shield made of a porous polymer material containing a chemical substance, it can withstand use in environments prone to condensation, such as cold regions and heated pools, and maintains temperature and humidity exchange efficiency. The purpose of the present invention is to provide a total heat exchanger that can extremely reduce the gas transfer rate. [Embodiments of the Invention] The present invention will be described in detail below. Commercially available porous polymer sheets made of materials such as polyethylene, polypropylene, cellulose nitrate, and polytetrafluoroethylene have low hygroscopicity, so water vapor passes through the pores on the surface of the porous sheet as a gas. On the other hand, air components such as oxygen, nitrogen, and carbon dioxide can also pass through the pores, so in total heat exchangers that use these polymer porous sheets as partition plates, air is supplied through the partition plates as described above. This causes a problem of mixing of the exhaust gas and the exhaust gas. The total heat exchanger of this invention is
A porous polymer sheet having countless pores with an average pore diameter of 0.1 to 10 μm is used as a porous polymer member, and a moisture permeable gas shield containing a hygroscopic substance by impregnation or coating is used as a partition plate. As a result, water vapor is once adsorbed and condensed on the surface of the partition plate, transported through the pores as liquid water, and permeated through the back surface by vaporizing again. On the other hand, air components cannot pass through because the pores are filled with liquid water. As mentioned above, the average pore diameter of the polymeric porous member is preferably 0.1 to 10 μm;
If the diameter is 0.1 μm or less, sufficient pores cannot be secured to transport liquid water, and if the diameter is 10 μm or more, it is too large to fill the pores with liquid water even if a hygroscopic substance is contained. As the hygroscopic substance, a hydrophilic polymer or a cationic polymer electrolyte containing a hygroscopic agent is effectively used. Lithium halides, particularly lithium chloride, are suitable as the moisture absorbent. Hydrophilic polymers include polyvinyl alcohol, polyvinyl methyl ether resin, polyacrylic acid resin,
Casein, gelatin, methylcellulose, etc. are used, but polyvinyl alcohol having an average degree of polymerization of 2000 or more is particularly suitable because it is less deformed even when dew condenses. This is because polyvinyl alcohol with an average degree of polymerization of 2,000 or more is difficult to dissolve in water even if it condenses during actual use. Examples of cationic polymer electrolytes include polyvinylbenzyltrimethylammonium chloride (manufactured by Dow Chemical), polypiperidinium chloride (manufactured by Merck & Co.), poly(2-acryloxyethylenedimethylsulfonium chloride), and polyglycidyltributylphosphonium Chloride etc. are used. Moisture absorbent concentration 2-10% by weight, hydrophilic polymer concentration 10
~20% by weight aqueous solution or 10-30% by weight cationic polyelectrolyte solution is used, and the thickness
It is contained by impregnating or coating the above-mentioned porous polymer sheet with a diameter of about 100 μm (suitable from the viewpoint of mechanical strength and pressure loss). The obtained moisture permeable gas shielding material had a high moisture absorption rate of 5 to 20% by weight, and had excellent moisture permeability and gas shielding properties. The above moisture permeable gas shield is used as a partition plate, and the thickness is 100~
A drawing in which a member is made by laminating a 200 μm (suitable for mechanical strength and pressure loss) hard polymer sheet with a corrugated spacer plate so that the direction of the spacer plate is perpendicular to every other row. A total heat exchanger was fabricated. However, the distance between the partition plates was 2 mm, and the wavy pitch of the spacer plates was 4 mm. Highly humid hot air is flowed as air supply to the total heat exchanger,
Dry cold air is passed through as exhaust air, and the temperature and humidity exchange efficiency is measured. In order to evaluate the degree of mixing between supply air and exhaust air, carbon dioxide is added from a carbon dioxide cylinder to the supply air, and carbon dioxide is added to the supply air and exhaust side. The carbon dioxide concentration at each outlet was measured. As a result, the temperature exchange efficiency is 70 to 80 at standard processing air volume.
% and humidity exchange efficiency of 60 to 70%, which is the same as that of conventional total heat exchangers using processed paper, and the carbon dioxide transfer rate was also lower at less than 3%, compared to about 20% for conventional products. This invention will be described below with reference to Examples and Comparative Examples. Example 1 Using lithium chloride as a moisture absorbent and polyvinyl alcohol with an average degree of polymerization of 2000 as a hydrophilic polymer, aqueous solutions of 5% by weight and 15% by weight, respectively, were prepared. Next, a porous polyethylene sheet having a basis weight of 60 g/m ² , a film thickness of 120 μm, and an average pore diameter of 1 μm was coated with the aqueous solution using a wire bar. The coating amount was 10 g/m ² , and the moisture absorption rate was 8% by weight at a temperature of 25° C. and a relative humidity of 60%.
A total heat exchanger as shown in the drawing was manufactured using the obtained moisture permeable gas shield as a partition plate. Example 2 A 20% by weight aqueous solution was prepared using polyvinylbenzyltrimethylammonium chloride, which is one of the cationic polymer electrolytes, as a hygroscopic substance. Next, using the same polyethylene porous sheet as in Example 1, the above aqueous solution was applied using a wire bar. The coating amount was 10g/ ^m2 , and the temperature was 25
The moisture absorption rate at 60% relative humidity was 6% by weight. A total heat exchanger as shown in the drawing was manufactured using the obtained moisture permeable gas shield as a partition plate. Comparative Example A total heat exchanger as shown in the drawing was manufactured using the same polyethylene porous sheet as in Example 1. The temperature and humidity exchange efficiency and carbon dioxide transfer rate of the total heat exchangers obtained in the above Examples and Comparative Examples were measured. The results are shown in the table. As is clear from the table, the temperature exchange efficiency of the example is the same as that of the comparative example, and the humidity exchange efficiency is almost the same, with Example 2 being slightly lower. On the other hand, the gas transfer rate is ~3% compared to ~20% in the comparative example, which is approximately 1/10

〔Effect of the invention〕

As explained above, according to the present invention, in the device in which two types of air currents are circulated through a partition plate, and sensible heat and latent heat of the two types of air flows are exchanged via the partition plate, the partition plate is separated from the partition plate. By constructing the board with a moisture-permeable gas shield made of a porous polymer material containing a hygroscopic substance, it can withstand use in environments prone to condensation, such as cold regions and heated pools.
This has the effect of providing a total heat exchanger that can extremely reduce the gas transfer rate while maintaining temperature/humidity exchange efficiency.

[Brief explanation of drawings]

The drawing is a perspective view showing the structure of a general total heat exchanger. In the figure, 1 is a partition plate, 2 is a spacing plate, 3 is a supply air flow path, 4 is an exhaust flow path, and a and b are respectively. Indicates the direction of air supply and exhaust.

Claims (1)

[Scope of Claims] 1. A device in which two types of air streams are passed through a partition plate, and sensible heat and latent heat of the two types of air streams are exchanged via the partition plate, wherein the partition plate is made of a hygroscopic substance. 1. A total heat exchanger comprising a moisture-permeable gas shield made of a porous polymer member containing. 2. The total heat exchanger according to claim 1, wherein the polymeric porous member is a sheet having pores with an average pore diameter of 0.1 to 10 μm. 3. The total heat exchanger according to claim 1 or 2, wherein the hygroscopic substance is a hydrophilic polymer containing a hygroscopic agent. 4. The total heat exchanger according to claim 3, wherein the hydrophilic polymer is polyvinyl alcohol having an average degree of polymerization of 2000 or more. 5. The total heat exchanger according to claim 1 or 2, wherein the hygroscopic substance is a cationic polymer electrolyte.