JP2009144930A - Total enthalpy heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a total enthalpy heat exchanger producing the same performance even in an environment where dew condensation occurs repeatedly, and improves the efficiency of total enthalpy heat exchange. <P>SOLUTION: In this total enthalpy heat exchanger, supply air and discharge air are caused to flow with a partition plate 4 between them, thus, sensible heat/latent heat exchange is conducted between the supply air and the discharge air via the partition plate 4. The partition plate 4 includes a non-woven fabric and a moisture-permeable gas-barrier material adherent thereto. The moisture-permeable gas-barrier material includes a water-insoluble hydrophilic polymeric material containing polyoxyethylene, and a moisture absorbent held in the hydrophilic polymeric material, and including at least one of deliquescent alkali metal salts and alkaline earth metal salts. The polyoxyethylene content in the hydrophilic polymeric material is 10-50 wt.%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a total heat exchanger used in, for example, a ventilator that simultaneously performs intake air from the outdoor to the indoors and exhaust air from the indoors to the outdoor.

  As a method of performing ventilation without impairing the indoor air conditioning effect, there is a method of performing ventilation while exchanging heat between intake and exhaust. In order to improve the efficiency of heat exchange, it is effective to simultaneously exchange temperature (sensible heat) and humidity (latent heat) between intake and exhaust (that is, perform total heat exchange).

  Conventionally, there has been proposed a total heat exchanger that performs total heat exchange between intake and exhaust through a partition plate in which a porous polymer sheet is impregnated or coated with a hygroscopic substance. As the hygroscopic substance, a hydrophilic polymer containing a hygroscopic agent is used (see Patent Document 1).

  Conventionally, a total heat exchanger that performs total heat exchange between intake and exhaust via a partition plate in which a water-insoluble hydrophilic polymer thin film is formed on one side of a porous sheet has also been proposed. The hydrophilic polymer thin film is made of a polyurethane resin containing 30% oxyethylene groups (see Patent Document 2).

Japanese Patent Publication No. 4-15476 Japanese Patent No. 2639303

  However, in the total heat exchanger shown in Patent Document 1, the retention capacity of the hygroscopic agent by the hydrophilic polymer is weak, and the amount of the hygroscopic agent that has flowed out due to condensation on the surface of the partition plate increases. The moisture permeability cannot be maintained for a long time. Therefore, when the total heat exchanger is used for a long period of time, the performance of the total heat exchanger is degraded.

  Further, in the total heat exchanger shown in Patent Document 2, since the hygroscopic agent is not included in the partition plate, the moisture permeability of the partition plate is deteriorated, and compared with the case where the partition plate includes the hygroscopic agent, the total heat is reduced. The exchange efficiency will be low.

  The present invention has been made to solve the above-described problems, and is capable of suppressing a decrease in performance even in an environment where condensation is repeated, and can improve the total heat exchange efficiency. The purpose is to obtain a heat exchanger.

  A total heat exchanger according to the present invention is a total heat exchanger that causes two types of airflow to flow through a partition plate, and performs heat exchange between sensible heat and latent heat of the two types of airflow through the partition plate. The board comprises a water-insoluble hydrophilic polymer material containing polyoxyethylene, and a hygroscopic agent held in the hydrophilic polymer material and having at least one of an alkali metal salt and an alkaline earth metal salt having deliquescence The content of polyoxyethylene in the hydrophilic polymer material is in the range of 10 to 50 wt%.

  In the total heat exchanger according to the present invention, the partition plate includes a water-insoluble hydrophilic polymer material containing polyoxyethylene, and an alkali metal salt and alkali that are held in the hydrophilic polymer material and have deliquescence properties. An absorbent containing at least one of earth metal salts, and the content of polyoxyethylene in the hydrophilic polymer material is in the range of 10 to 50 wt%. The association effect (chain formation effect) makes it easier for the hygroscopic agent and the hydrophilic polymer to be compatible with each other, thereby preventing the hygroscopic agent from being lost. In addition, it is possible to prevent the hydrophilic polymer material itself from flowing due to condensation of the partition plate, and it is possible to suppress a decrease in gas shielding properties. Accordingly, it is possible to suppress a decrease in performance even in an environment where condensation is repeated, and to improve the total heat exchange efficiency.

Embodiment FIG. 1 is a perspective view showing a total heat exchanger according to an embodiment of the present invention. In the figure, a total heat exchanger 1 is a laminated body in which an air supply layer 2 through which an air flow of supply air passes and an exhaust layer 3 through which an air flow of exhaust passes are alternately stacked via a partition plate 4. is there. The air supply layer 2 is provided with an air supply passage 5 that guides the airflow of the supply air along the partition plate 4. The exhaust layer 3 is provided with an exhaust passage 6 that guides an exhaust airflow along the partition plate 4. The air supply passage 5 and the exhaust passage 6 are respectively formed by corrugated spacing plates 7 that keep the spacing between the partition plates 4. A direction A in which the airflow of the supply air is guided by the air supply passage 5 and a direction B in which the airflow of the exhaust air is guided by the exhaust passage 6 are perpendicular to each other.

  Each partition plate 4 has a nonwoven fabric (porous sheet) and a membrane-like moisture-permeable gas shield that is attached to the nonwoven fabric and has a property of blocking air and allowing heat and water vapor to pass through.

  The moisture-permeable gas shielding material includes a water-insoluble hydrophilic polymer material containing polyoxyethylene and at least any one of an alkali metal salt and an alkaline earth metal salt held in the hydrophilic polymer material and having deliquescence. And a hygroscopic agent containing That is, the moisture-permeable gas shielding material is a hygroscopic agent-containing polymer body in which a hygroscopic agent is held in a water-insoluble hydrophilic polymer material containing polyoxyethylene. The polyoxyethylene content in the hydrophilic polymer material is in the range of 10 to 50 wt%. That is, 10-50 wt% of polyoxyethylene chains are contained in the molecule of the hydrophilic polymer material.

The nonwoven fabric is made of polyester fibers. The basis weight of the nonwoven fabric is 15 g / m ² , the thickness of the nonwoven fabric is 35 μm, and the air permeability of the nonwoven fabric is 280 cc / cm ² / sec.

  The interval plate 7 is manufactured by processing a processed paper into a corrugated plate shape. The thickness of the processed paper is set within a range of 50 μm to 200 μm.

  Next, the operation will be described. For example, when cold and dry outside air is passed through the air supply layer 2 as supply air, and warm and humid room air is passed through the exhaust layer 3 as exhaust, each air flow of supply and exhaust (two air flows) ) Flows across each partition plate 4. At this time, heat and water vapor pass through the partition plate 4, and heat exchange of sensible heat and latent heat is performed via the partition plates 4 between the supply air and the exhaust air. Thus, the supply air is warmed and humidified and supplied to the room, and the exhaust is cooled and dehumidified and discharged to the outside.

  Hereinafter, Examples 1 to 7 in this embodiment and Comparative Examples 1 to 5 for comparison with Examples 1 to 7 will be described.

Example 1.
In this example, lithium chloride is used as the hygroscopic agent. A polyurethane resin is used as the water-insoluble hydrophilic polymer material. Furthermore, the polyoxyethylene content in the water-insoluble hydrophilic polymer material is 50 wt%. Furthermore, the content rate of the hygroscopic agent in the moisture-permeable gas shield is set to 10 wt%.

  Next, the manufacturing method of the total heat exchanger 1 is demonstrated. First, diphenylmethane diisocyanate (hereinafter referred to as “MDI”), 1,4-butanediol (hereinafter referred to as “BG”), polyethylene glycol (hereinafter referred to as “PEG”) and polytetramethylene glycol (hereinafter referred to as “PTMG”). ) And then polymerized by heating. This produces a polyurethane resin containing 50 wt% of polyoxyethylene chains (derived from the raw material PEG) in the molecule.

  Thereafter, the prepared polyurethane resin is dissolved in dimethylformamide to form a polyurethane solution, and then a polyurethane resin mixed solution in which the polyurethane solution and lithium chloride are mixed is prepared. At this time, the weight ratio of the polyurethane resin to lithium chloride is set to 9: 1.

  Thereafter, the polyurethane resin mixed solution is applied to the release film with a comma coater and dried by heating to produce a lithium chloride-containing polyurethane resin film having a thickness of 20 μm as a moisture-permeable gas shield.

  Thereafter, the lithium chloride-containing polyurethane resin film is transferred from the release film to the nonwoven fabric by a hot roll. Thus, the partition plate 4 in which the lithium chloride-containing polyurethane resin film is formed on the nonwoven fabric is produced.

  Then, the laminated unit body which bonded together the spacing plate 7 and the partition plate 4 which were wave-shaped is produced. After that, after forming the laminated unit body so that the shape of the partition plate 4 is a 30 cm square, a plurality of laminated unit bodies are laminated so that the direction of the wave groove of the spacing plate 7 is orthogonal every other step. In this way, the total heat exchanger 1 having a height of 50 cm is produced.

Example 2
In this example, the content of the hygroscopic agent in the moisture-permeable gas shield is 33 wt%. That is, a polyurethane resin mixed solution was prepared by mixing a polyurethane solution and lithium chloride so that the weight ratio of polyurethane resin to lithium chloride was 2: 1. Thereafter, the total heat exchanger was prepared in the same manner as in Example 1. 1 is produced. Other configurations are the same as those of the first embodiment.

Example 3 FIG.
In this example, the content of the hygroscopic agent in the moisture-permeable gas shield is 50 wt%. That is, a polyurethane resin mixed solution in which a polyurethane solution and lithium chloride were mixed so that the weight ratio of the polyurethane resin and lithium chloride was 1: 1 was prepared. Thereafter, the total heat exchanger was prepared in the same manner as in Example 1. 1 is produced. Other configurations are the same as those of the first embodiment.

Example 4
In this example, the polyoxyethylene content in the water-insoluble hydrophilic polymer material is 30 wt%. That is, by changing the blending ratio of PEG and PTMG, a polyurethane resin containing 30 wt% of polyoxyethylene chains in the molecule is produced, and thereafter, the total heat exchanger 1 is produced in the same manner as in Example 1. . Other configurations are the same as those of the first embodiment.

Embodiment 5 FIG.
In this example, the polyoxyethylene content in the water-insoluble hydrophilic polymer material is 10 wt%. That is, by changing the blending ratio of PEG and PTMG, a polyurethane resin containing 10 wt% of polyoxyethylene chains in the molecule is produced, and thereafter, the total heat exchanger 1 is produced in the same manner as in Example 1. . Other configurations are the same as those of the first embodiment.

Example 6
In this example, calcium chloride is used as a hygroscopic agent. Other configurations are the same as those of the first embodiment.

Example 7
In this example, polyacrylic resin is used as a water-insoluble hydrophilic polymer material. Other configurations are the same as those of the first embodiment.

  Next, the manufacturing method of the total heat exchanger 1 in this example will be described. First, polyethylene glycol monoacrylate and methyl methacrylate are polymerized to prepare a polyacrylic resin so that the weight fraction of the polyoxyethylene chain portion of polyethylene glycol monoacrylate is 50 wt%. That is, a polyacrylic resin containing 50% by weight of polyoxyethylene chains in the molecule is prepared.

  Thereafter, the prepared polyacrylic resin is dissolved in acetone to form a polyacrylic solution, and then a polyacrylic resin mixed solution in which the polyacrylic solution and the lithium chloride aqueous solution are mixed is prepared. At this time, the weight ratio of polyacrylic resin to lithium chloride is set to 9: 1.

  Thereafter, the polyacrylic resin mixed solution is applied to the release film with a comma coater and dried by heating to produce a lithium chloride-containing polyacrylic resin film having a thickness of 20 μm as a moisture-permeable gas shield.

  Thereafter, the lithium chloride-containing polyacrylic resin film is transferred from the release film to the nonwoven fabric by a hot roll. Thus, the partition plate 4 in which the lithium chloride-containing polyacrylic resin film is formed on the nonwoven fabric is produced. The subsequent steps are the same as in the first embodiment.

Comparative Example 1
In this example, the polyoxyethylene chain is not contained in the molecule of the hydrophilic polymer material. That is, the polyoxyethylene content in the hydrophilic polymer material is 0 wt%. Moreover, the polyurethane resin obtained by mixing MDI, BG, and PTMG and carrying out heat polymerization is used as a hydrophilic polymer material. Other configurations are the same as those of the first embodiment.

Comparative Example 2
Also in this example, the polyoxyethylene chain is not contained in the molecule of the hydrophilic polymer material. That is, the polyoxyethylene content in the hydrophilic polymer material is 0 wt%. Polyvinyl alcohol resin is used as a hydrophilic polymer material. Other configurations are the same as those of the first embodiment.

  The partition plate 4 in this example is manufactured as follows. First, an aqueous solution containing a polyvinyl alcohol resin and lithium chloride is prepared so that the weight ratio of the polyvinyl alcohol resin and lithium chloride is 9: 1. Then, this aqueous solution is apply | coated to the nonwoven fabric piled up on the release film with a comma coater, and it heat-drys. Then, a release film is peeled off and the partition plate 4 in which the lithium chloride containing polyvinyl alcohol resin film was formed in the nonwoven fabric is produced.

Comparative Example 3
In this example, the absorbent is not retained in the hydrophilic polymer material. That is, the content rate of the absorbent in the moisture-permeable gas shield is set to 0 wt%. Moreover, the polyurethane resin produced only from the polyurethane solution of Example 1 is used as the hydrophilic polymer material. Other configurations are the same as those of the first embodiment.

  The partition plate 4 in this example is manufactured as follows. First, the same polyurethane solution as in Example 1 is prepared. Thereafter, the polyurethane solution is applied to the release film with a comma coater and dried by heating to produce a polyurethane resin film. Thereafter, the polyurethane resin film is transferred from the release film to the nonwoven fabric by a hot roll to produce the partition plate 4.

Comparative Example 4
In this example, a polyoxyethylene resin having an average molecular weight of 200,000 is used as the hydrophilic polymer material. That is, the polyoxyethylene content in the hydrophilic polymer material is 100 wt%. Other configurations are the same as those of the first embodiment.

  The partition plate 4 in this example is manufactured as follows. First, an aqueous solution containing the polyoxyethylene resin and lithium chloride is prepared so that the weight ratio of the polyoxyethylene resin and lithium chloride is 9: 1. Then, this aqueous solution is apply | coated to the nonwoven fabric piled up on the release film with a comma coater, and it heat-drys. Thereafter, the release film is peeled off to produce the partition plate 4 in which the lithium chloride-containing polyoxyethylene resin film is formed on the nonwoven fabric.

Comparative Example 5
In this example, the content of polyoxyethylene in the hydrophilic polymer material is 70 wt%. That is, by changing the mixing ratio of MDI, BG, PTMG and PEG, a polyurethane resin containing 70 wt% of polyoxyethylene chains in the molecule was prepared. I am making it. Other configurations are the same as those of the first embodiment.

  Next, performance evaluation of each total heat exchanger 1 of Examples 1 to 7 and Comparative Examples 1 to 5 will be described. The performance evaluation of each total heat exchanger 1 is performed by determining the gas shielding properties of the partition plate 4 at the initial stage and after the dew condensation test, and the dew condensation resistance of the total heat exchanger 1 with respect to the humidity exchange efficiency. .

The gas shielding property of the partition plate 4 is evaluated by measuring the air permeability of the partition plate 4 in accordance with JIS P 8117. That is, the time required for 100 cm ³ of air to pass through a part of the partition plate 4 having an area of 645 mm ² is measured, and the measurement result is defined as the air permeability. Further, the measurement of the air permeability of the partition plate 4 is performed at any five locations of the partition plate 4. As a result, if the air permeability at any five locations of the partition plate 4 is 10,000 seconds or more, a good judgment (◯) that the gas shielding property is good is performed, and at any five locations of the partition plate 4 If any of the air permeability is less than 10000 seconds, a failure determination (x) that the gas shielding property is poor is performed.

  The dew condensation test of the partition plate 4 is performed by simulating the dew condensation state by repeatedly immersing the partition plate 4 in water and then drying it. The initial gas shielding performance of the partition plate 4 is evaluated based on the measurement result of the air permeability of the partition plate 4 before the condensation test, and the gas shielding performance after the condensation test of the partition plate 4 is evaluated after the condensation test. This is performed based on the measurement result of the air permeability of the partition plate 4.

  Evaluation of condensation resistance of the total heat exchanger 1 with respect to humidity exchange efficiency is based on the humidity exchange efficiency before and after the dew condensation test of the total heat exchanger 1 in two chambers in Annex 4 of JIS B 8628 (total heat exchanger). It is measured by a method according to the law, and the measurement results before and after the condensation test are compared. That is, after measuring the humidity exchange efficiency of the total heat exchanger 1, a dew condensation test of the total heat exchanger is performed, and the humidity exchange efficiency of the total heat exchanger 1 after the dew condensation test is measured again. As a result, if the rate of decrease in humidity exchange efficiency from the pre-condensation test to the post-condensation test is less than 10%, a good judgment (○) is made that the dew resistance is good. The defect judgment (x) that the property is bad is performed.

  In the measurement of the humidity exchange efficiency, the condition of the primary air flow (supply air) is 27 ° C. and the relative humidity is 52.7% rh, and the condition of the secondary air flow (exhaust air) is 35 ° C. and the relative humidity is 64.3. % Rh. In addition, the dew condensation test of the total heat exchanger 1 is performed by simulating the dew condensation state by repeatedly immersing the total heat exchanger 1 in water and then drying it several times.

  FIG. 2 is a table showing the results of performance evaluation of the total heat exchanger 1 of FIG. 1 for each of Examples 1 to 7 and Comparative Examples 1 to 5. FIG. 2 shows the results of performance evaluation of the total heat exchanger 1, the polyoxyethylene content (wt%) in the hydrophilic polymer material (resin), and the moisture absorbent content in the moisture-permeable gas shield. The rate (wt%) and the values (%) of the temperature exchange efficiency, humidity exchange efficiency, and total heat exchange efficiency of the total heat exchanger 1 are shown for each of Examples 1 to 7 and Comparative Examples 1 to 5. Yes. Moreover, about the comparative examples 4 and 5 in which the gas-shielding property after the dew condensation test of the partition plate 4 has deteriorated, the dew resistance of the total heat exchanger 1 is not evaluated.

  As shown in FIG. 2, the performances of the total heat exchanger 1 of Examples 1 to 7 are all the initial gas barrier property of the partition plate 4 and the respective gas shielding properties after the dew condensation test, and the dew condensation resistance of the total heat exchanger 1. You can see that it is excellent.

  Moreover, from the results of Examples 1, 4 and 5, and Comparative Examples 4 and 5, the higher the content of polyoxyethylene chains in the resin used for the partition plate 4, the higher the humidity exchange efficiency of the total heat exchanger 1 It turns out that becomes high.

  Further, from comparison between Examples 1 to 7 and Comparative Examples 4 and 5, when the content of the polyoxyethylene chain in the resin is higher than 50 wt%, the gas shielding property after the dew condensation test of the partition plate 4 is deteriorated. I understand that This is considered to be because when the content of the highly hydrophilic polyoxyethylene chain becomes too high, the resin itself flows due to condensed water or the like, and the gas shielding property of the partition plate 4 cannot be maintained. In addition, in the result of the comparative example 4, it turns out that the initial gas-shielding property of the partition plate 4 is also getting worse. This is considered to be because when the resin was applied to the nonwoven fabric and heated and dried, volume shrinkage occurred due to crystallization of the polyoxyethylene resin, and pinholes were generated in the partition plate 4.

  Furthermore, from the comparison between Examples 1 to 7 and Comparative Examples 1 and 2, when the content of the polyoxyethylene chain in the resin is lower than 10 wt%, the dew resistance of the total heat exchanger 1 is deteriorated. I understand that. This is because if the content of the polyoxyethylene chain in the resin becomes too low, the retention due to the association effect between the hygroscopic agent and the polyoxyethylene chain becomes weak, and the hygroscopic agent tends to flow away due to condensation of the partition plate 4. This is probably because of this.

  Therefore, it can be seen that the polyoxyethylene chain content in the resin should be in the range of 10 to 50 wt%.

  Further, from the comparison between Example 1 and Comparative Example 3, the humidity exchange efficiency and the total heat exchange efficiency of the total heat exchanger 1 differ greatly depending on whether or not a hygroscopic agent is added to the resin used for the partition plate 4. I understand. That is, in Comparative Example 3 in which the hygroscopic agent is not added in the resin, the humidity exchange efficiency and the total heat exchange efficiency of the total heat exchanger 1 are significantly higher than those in Example 1 in which the hygroscopic agent is added in the resin. It is getting worse.

  Further, from the results of Examples 1 to 3, the total heat exchanger 1 increases as the amount of the hygroscopic agent (lithium chloride) added to the resin increases (that is, the content of the hygroscopic agent in the moisture-permeable gas shield increases). It can be seen that the humidity exchange efficiency and the total heat exchange efficiency are increased.

  Furthermore, it can be seen from the results of Examples 1 and 6 that the partition plate 4 exhibits high moisture permeability like lithium chloride even when the hygroscopic agent is calcium chloride. However, from the viewpoint of moisture permeability, the hygroscopic agent is preferably lithium chloride.

  In addition, from the results of Examples 1 and 7, the type of the resin component used for the partition plate 4 greatly affects the performance of the total heat exchanger 1 if the same amount of polyoxyethylene chain is included in the molecule. I understand that I don't.

  In such a total heat exchanger, a water-insoluble hydrophilic polymer material containing polyoxyethylene, and alkali metal salt and alkaline earth metal salt that are held in the hydrophilic polymer material and have deliquescence properties. A moisture-permeable gas shield having an absorbent containing at least one of them is used for the partition plate 4, and the content of polyoxyethylene in the hydrophilic polymer material is in the range of 10 to 50 wt%. As a result of the association effect (chain formation effect) between the agent and polyoxyethylene, the hygroscopic agent and the hydrophilic polymer are easily compatible with each other, and it is possible to prevent the hygroscopic agent from being lost. Further, it is possible to prevent the hydrophilic polymer material itself from flowing, and it is possible to suppress a decrease in gas shielding property due to condensation of the partition plate 4. Accordingly, it is possible to suppress a decrease in performance even in an environment where condensation is repeated, and to improve the total heat exchange efficiency.

  Moreover, since the humidity exchange efficiency of the total heat exchanger 1 is improved when the hygroscopic agent is lithium chloride, the total heat exchange efficiency can be further improved.

It is a perspective view which shows the total heat exchanger by embodiment of this invention. It is a table | surface which shows the result of the performance evaluation of the total heat exchanger of FIG. 1 for every Examples 1-7 and Comparative Examples 1-5.

Explanation of symbols

  1 Total heat exchanger, 4 partition plate.

Claims (2)

A total heat exchanger that flows two kinds of airflows across a partition plate and exchanges sensible heat and latent heat of the two kinds of airflows through the partition plate,
The partition plate comprises at least one of a water-insoluble hydrophilic polymer material containing polyoxyethylene and an alkali metal salt and an alkaline earth metal salt held in the hydrophilic polymer material and having deliquescence. Including a hygroscopic agent,
The total heat exchanger, wherein the polyoxyethylene content in the hydrophilic polymer material is in the range of 10 to 50 wt%.   The total heat exchanger according to claim 1, wherein the hygroscopic agent is lithium chloride.

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