JP2008224113A - Desiccant air-conditioning system and moisture absorbing/desorbing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a desiccant air conditioning system and a moisture absorbing/desorbing method capable of minimizing energy consumption, and constantly controlling moisture absorption/desorption. <P>SOLUTION: A typical constitution of this photocatalyst desiccant air conditioning system comprises a dehumidifying rotor 101 including a photocatalyst material, an activating means for activating the photocatalyst material of the dehumidifying rotor 101, and a ventilating means (air intake passage 110 and air discharge passage 111) for circulating gases of two systems to the dehumidifying rotor 101. The dehumidifying rotor 101 is kept in an excess moisture state by allowing the gas of one system to adsorb moisture by activating the photocatalyst material of the dehumidifying rotor 101, and the gas of the other system is allowed to release moisture by stopping the activation of the photocatalyst material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a desiccant air-conditioning system that absorbs and releases moisture by temporarily supporting moisture on a hygroscopic material, and a method for absorbing and releasing moisture.

  Conventionally, in order to control the humidity of room air (especially dehumidification), a supercooling system or a desiccant air conditioner has been used. The total heat exchanger also affects the moisture in the air because it handles latent heat.

  The supercooling method is a method in which air is cooled and condensed to separate moisture from the air. When the air to be discharged becomes cold, the comfort is impaired, so the gas is often reheated.

  The desiccant air conditioner uses a moisture absorbent material (desiccant) such as silica gel or zeolite to remove moisture in the air. Desiccant air conditioning requires heating to dehumidify moisture from the hygroscopic material (regenerate the hygroscopic material). This utilizes the property that when the temperature rises, the hygroscopic material lowers its adsorption capacity and releases moisture (saturated vapor pressure rises).

  FIG. 5 is a diagram showing a schematic configuration of the desiccant air conditioner. In the desiccant air conditioner 500 shown in FIG. 5A, the dehumidification rotor 501 enclosing a moisture absorbent and the sensible heat rotor 502 that exchanges heat by intake and exhaust are rotating at a low speed. Two flow passages, an inlet passage 510 and an exhaust passage 511, are provided, and gas passes through the dehumidification rotor 501 and the sensible heat rotor 502.

  The temperature and humidity shown in FIG. 5A are examples. FIG. 5B shows the relationship between temperature and vapor pressure. The gas (C1) (for example, outside air) of 30 ° C. 16 g / kg sucked into the intake passage 510 has a temperature increased to 56 ° C. in the dehumidification rotor 501 due to the release of latent heat due to moisture absorption and the absorption of heat from the dehumidification rotor 501. Decreases to 9 g / kg (C2). Then, the heat is absorbed by the sensible heat rotor 502, the temperature is lowered, and the gas is discharged as 35 ° C. gas (C3). The gas (C4) (for example, room air) at 30 ° C. sucked into the exhaust passage 511 is heated by the sensible heat rotor 502 to 51 ° C. (C5) and further heated by the heater 503. It is heated to 80 ° C. (C6), and the dehumidification rotor 501 is heated and dehumidified to be discharged as a gas (C7) at 54 ° C. and 23 g / kg.

  FIG. 5B also shows the relationship between the temperature in the dehumidification rotor and the vapor pressure with a thick arrow. When the dehumidifying rotor 501 rotates in the direction of the arrow in FIG. 5A, a → b is an operation in the exhaust passage 511. The dehumidifying rotor 501 is heated by the gas C6, and the dehumidifying rotor is heated. Then, the adsorption capacity of the hygroscopic material is lowered and moisture is released. Since the moisture released at this time is carried away by the gas C6, the vapor pressure is kept constant. b → c is the operation of the first half of the intake passage 510. The dehumidification rotor 501 is cooled by the gas C1, and the temperature is lowered and the adsorption capacity is improved to absorb moisture, thereby reducing the vapor pressure. c → a is the latter half of the operation of the intake path 510. Although the dehumidifying rotor 501 is further cooled by the gas C1, the vapor pressure in the rotor also rises because the adsorption capacity is gradually saturated by absorbing the water vapor contained in the gas C1. In this way, moisture can be absorbed from the air in the intake passage 510 and released into the air in the exhaust passage 511.

  FIG. 6 is a diagram showing a schematic configuration of a rotary total heat exchanger. The total heat exchanger exchanges sensible heat and latent heat (total heat) between two systems of gas, and there are a rotary type and a stationary type. The total heat exchanger 600 shown in FIG. 6 allows two systems of gas to pass through the inlet passage 610 and the exhaust passage 611 while rotating a honeycomb heat exchange rotor 601 typically made of aluminum at a low speed. In the exhaust path 611, the heat exchange rotor 601 is stored and humidified by the heat (temperature, humidity) of the exhaust. The heat exchange rotor 601 rotates to release heat and release moisture from the gas in the intake passage 610. That is, the total heat exchanger can be said to be a system that ventilates while relaxing the temperature difference and humidity difference between the outside air and the inside air.

  On the other hand, titanium oxide is typically known as a photocatalyst material, and is activated by irradiating ultraviolet rays having a wavelength of 400 nm or less, and exhibits a strong oxidizing action and a superhydrophilic action. The oxidizing action can be used for sterilization treatment, and the superhydrophilic action can be used as an anti-fogging function or an anti-staining function.

  Since the photocatalyst acts on the surface, the greater the surface area, the higher the efficiency. Patent Document 1 (Japanese Patent Laid-Open No. 11-138017) proposes a photocatalytic silica gel in which titanium oxide is contained in the pores of the silica gel. According to Patent Document 1, the photocatalytic silica gel can adsorb a large amount of harmful substances in the air, and can be quickly and efficiently decomposed and removed by irradiating light.

Titanium oxide itself is a material that has been known for a long time, and has been used as a white pigment or an ultraviolet absorber. Further, Patent Document 2 (Japanese Patent Application Laid-Open No. 2006-272329) describes a configuration in which titanium oxide is used as a hygroscopic material by processing into a long fiber shape. According to Patent Document 2, such a hygroscopic material has a high water supply speed and can release water relatively easily.
Japanese Patent Laid-Open No. 11-138017 JP 2006-272329 A

  However, in the conventional supercooling system, air is cooled and then reheated. Therefore, in order to realize constant temperature and humidity, power for moving the refrigerator is necessary, and energy for reheating is necessary. Therefore, there is a problem that energy consumption is large.

  Further, in the conventional desiccant air conditioner, it is necessary to heat the gas using a heat source at the time of regeneration in order to reduce the adsorption capacity of the hygroscopic material. This is because the adsorption power of the hygroscopic material exceeds the saturated water vapor pressure at room temperature, and therefore, it is necessary to raise the temperature to a saturated water vapor pressure that exceeds the adsorption power for regeneration. For this reason, although the energy consumption is smaller than that of the supercooling method, the energy consumption of the heat source is still necessary.

  Since the total heat exchanger works so that the high temperature side becomes high humidity in the case of the rotary type, it functions as dehumidification during summer cooling and humidification during winter heating, and it is certainly convenient in general. However, there is a problem that it cannot be controlled. In the case of the static type, when the partial pressure difference is small because the moisture (humidity) is exchanged using the moisture vapor partial pressure difference of the highly moisture permeable material element (usually moisture-treated special processed paper) that separates the exhaust and intake air from the room. Is less effective. Therefore, a large effect can be obtained when the temperature difference and humidity difference between the indoor and outdoor are large as in winter, but the effect cannot be expected when the temperature difference and humidity difference between indoor and outdoor are small as in summer. is there.

  Accordingly, an object of the present invention is to provide a desiccant air-conditioning system and a moisture absorption / release method that consume extremely little energy and can always control moisture absorption / release.

  In order to solve the above problems, a typical configuration of a photocatalytic desiccant air conditioning system according to the present invention includes an element containing a photocatalytic material, an activating means for activating the photocatalytic material of the element, and two systems of gas in the element. A ventilation means for circulating the gas, and by activating the photocatalytic material of the element to absorb moisture from the gas of one system, the element is brought into an overhumid state, and the activation of the photocatalytic material is stopped to stop the activation of the other system. It is characterized by letting the gas emit moisture.

  According to the above configuration, the photocatalyst material can be brought into an overhumid state by absorbing moisture in an activated state, and can be dehumidified simply by stopping activation without heating. Therefore, energy consumption is extremely small and moisture absorption / release can be controlled regardless of the season.

  The activation means may be a light irradiation means. As the light, when the photocatalytic material is titanium oxide, it preferably contains ultraviolet light having a wavelength of 400 nm or less.

  The activation means may be an electric field application means. By applying an electric field, the photocatalytic material can be activated in the same manner as when light is irradiated.

  The element preferably includes a hygroscopic material containing a photocatalytic material in a porous, honeycomb-like or fibrous carrier. Since the photocatalytic function functions on the surface, the function can be effectively exhibited by combining with a material having a large surface area.

  In addition, a typical structure of the moisture absorption / release method according to the present invention is that the moisture absorption material containing a photocatalyst material contained in a porous, honeycomb-like or fibrous carrier is activated to absorb moisture, so that the photocatalyst It is characterized in that moisture is released by stopping the activation of the material.

  According to the above-described method, it is possible to provide a moisture absorption / release method that can exhibit high moisture absorption performance with extremely small energy consumption and can be easily released.

  As the photocatalytic material, titanium oxide can be suitably used. In addition to titanium oxide, any material that exhibits a photocatalytic action by light such as ultraviolet rays, such as zinc oxide and strontium titanate known as photocatalysts, can be used as the photocatalytic material according to the present invention.

  According to the present invention, the photocatalyst material can be brought into an overhumid state by absorbing moisture in an activated state, and can be dehumidified simply by stopping activation without heating. Therefore, energy consumption is extremely small, moisture absorption / release can be controlled regardless of the season, and the regeneration temperature can be lowered.

  The present inventors have intensively studied to solve the above problems, and the saturated water vapor pressure is reduced due to the presence of the hygroscopic material, but the saturated water vapor pressure can be further reduced by combining the photocatalytic action with the hygroscopic material. As a result, the present invention has been completed.

  FIG. 1 is a diagram illustrating an example of a desiccant air conditioning system using a photocatalytic action according to the present embodiment. Note that dimensions, materials, and other specific numerical values shown in the following examples are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified.

  A photocatalytic desiccant air conditioning system (hereinafter referred to as “air conditioning system 100”) shown in FIG. 1A includes a dehumidification rotor 101 as an element containing a photocatalytic material. The dehumidifying rotor 101 rotates at a low speed of about 10 times per minute. In the vicinity of the dehumidifying rotor 101, an ultraviolet irradiation device 102 is provided as light irradiation means as an example of activation means for activating the photocatalytic material. Further, the dehumidifying rotor 101 is provided with a ventilation means for allowing two systems of gas, an inlet passage 110 and an exhaust passage 111, to circulate.

  The dehumidifying rotor 101 has good air permeability and contains a photocatalytic material. In order to make the dehumidification rotor 101 contain the photocatalyst material, it is possible to enclose a moisture absorbing material containing the photocatalyst material in a porous, honeycomb-like or fibrous carrier. Since the photocatalytic function functions on the surface, the function can be effectively exhibited by combining with a material having a large surface area. For example, photocatalytic silica gel can be used as a hygroscopic material, and can be sealed in a container that transmits ultraviolet light and allows gas to flow. Alternatively, a specially processed paper may contain a photocatalytic material. As yet another example, the photocatalyst itself may be a fine fiber or a non-woven fabric. Titanium oxide is most suitable as the photocatalytic material, but other materials may be used.

  The ultraviolet irradiation device 102 is disposed on the inlet path 110 side, that is, on the processing side that performs moisture absorption. Moreover, the ultraviolet irradiation device 102 is not limited to one, but may be disposed on both the front and rear sides of the dehumidification rotor 101 to irradiate both surfaces with ultraviolet rays. The ultraviolet light is desirably light having a wavelength of 400 nm or less, but may include other wavelengths. In other words, the light may include ultraviolet light having a wavelength in the above range.

  The intake passage 110 typically introduces outside air and exhausts the absorbed air into the room. The exhaust path 111 introduces indoor air and exhausts it outside the room.

  In the air conditioning system 100 having the above-described configuration, when the outside air is introduced through the intake passage 110, the ultraviolet light irradiation device 102 irradiates the dehumidification rotor 101 with ultraviolet rays to activate the photocatalyst. Then, since the saturated vapor pressure is lowered, the hygroscopic material inside the dehumidifying rotor 101 is in an excessively humid state. Thereby, the air discharged | emitted indoors can be dehumidified effectively.

  When the dehumidifying rotor 101 rotates and moves into the exhaust path 111, the photocatalyst stops activating because ultraviolet rays are not irradiated in the exhaust path 111. Then, since the saturated vapor pressure increases, moisture cannot be retained in the hygroscopic material, and moisture is released. The moisture is discharged to the outside by the air flowing through the exhaust path 111. That is, moisture can be released only by stopping activation without heating, energy consumption is extremely small, and moisture absorption / release can be controlled regardless of the season.

  The temperature and humidity shown in FIG. 1 (a) are exemplary. FIG. 1B shows the relationship between the temperature in the dehumidification rotor 101 and the vapor pressure. The gas (A1) (eg, outside air) of 30 ° C. 16 g / kg sucked into the intake passage 110 is absorbed (dehumidified) by the dehumidification rotor 101, and the temperature rises to 35 ° C. due to the release of latent heat. Decreases to 13.8 g / kg and is discharged (A2). Here, since the temperature of the dehumidifying rotor 101 does not rise, the temperature rise is extremely small as compared with the conventional desiccant air conditioning shown in FIG.

  When the dehumidifying rotor 101 rotates and the absorbed portion reaches the exhaust path 111 side, the ultraviolet rays irradiated from the ultraviolet irradiation device 102 are blocked. Then, the adsorptive power of the hygroscopic material is lowered and moisture is released. The gas (A3) (for example, indoor air) at 30 ° C. sucked into the exhaust passage 111 takes away moisture released from the dehumidification rotor 101. Since evaporation is also accompanied at this time, the heat of evaporation is deprived and the temperature is lowered to 25 ° C., and the humidity is increased and humidified to 18.2 g / kg and released.

  That is, by activating the photocatalyst of the hygroscopic material, the saturated water vapor pressure is reduced (the vapor pressure is increased). A low saturated water vapor pressure means that moisture cannot be present in the air, meaning that moisture is adsorbed by the hygroscopic material (in general, the moisture absorption amount of the hygroscopic material is equal to the partial pressure of water vapor). Proportional). The ability to lower the saturated water vapor pressure means that the moisture absorption performance can be increased. Therefore, first, higher moisture absorption performance can be obtained.

  Next, the fact that the increase in moisture absorption performance is due to the photocatalytic action means that if the activation is stopped, the moisture absorption performance decreases, and moisture that cannot be held is released. That is, it is possible to release moisture without heating only by stopping the activation of the photocatalytic material.

  Note that the photocatalyst material is typically titanium oxide, and as described above, proposals have been made to use titanium oxide as a hygroscopic material (see Patent Document 2 above). However, Patent Document 2 merely states that titanium oxide is used as the material of the fiber and is a material known as a photocatalyst (paragraph 0002 of Patent Document 2). ) Is heated by warm air or electromagnetic waves (paragraph 0007 of Patent Document 2). Therefore, Patent Document 2 does not describe or suggest a method for increasing the moisture absorption performance by combining the photocatalytic action with the moisture absorbent, and releasing the moisture without heating.

  That is, in the present embodiment, the moisture absorbing material containing the photocatalyst material in the porous, honeycomb-like or fibrous carrier is activated to absorb moisture, and is released by stopping the activation of the photocatalyst material. It is characterized by moistening. As a result, moisture can be released only by stopping the activation without heating, energy consumption is extremely small, and moisture absorption / release can be controlled regardless of the season.

  As shown in FIG. 1, when moisture is absorbed through the dehumidification rotor 101 in the intake passage 110, the temperature rises slightly because the latent heat of water vapor is released. Further, when moisture is released in the exhaust passage 111, the sensible heat is taken away by the latent heat of vaporization of water, so that the temperature slightly decreases. However, all are slight fluctuations and do not need to be adjusted with a heat source. Therefore, according to this embodiment, compared with the conventional desiccant air conditioning, the regeneration temperature can be lowered, and the energy consumption can be extremely reduced.

  Further, by opening both ends of the inlet and outlet of the air inlet passage 110 in the room and opening both ends of the exhaust passage 111 to the outside of the room, it is possible to provide a device that constantly dehumidifies the air in the room. If this is reversed, it can be used as a humidifier that continues to supply moisture from the outside air into the room. At this time, since moisture is sterilized and purified by ultraviolet rays and a photocatalyst, normal water vapor can always be supplied.

  FIG. 2 shows a configuration in which a dehumidifying rotor 101 containing a photocatalytic material (for example, photocatalytic silica gel) and an ultraviolet irradiation device 102 are included in the configuration of a conventional desiccant air conditioner. The temperature and humidity shown in FIG. 2 (a) are exemplary. FIG. 2B shows the relationship between the temperature in the dehumidification rotor 101 and the vapor pressure.

  According to the above configuration, it is possible to promote moisture absorption and moisture release of the dehumidifying rotor 101 by irradiation and blocking of ultraviolet light as compared with the conventional configuration shown in FIG. Therefore, the heating for dehumidifying from the dehumidifying rotor 101 can be reduced, and referring to the temperature and humidity example shown in FIG. 2A, the heating by the heater 503 is reduced (the temperature of the air C6 is reduced to 80). (° C. → 70 ° C.), it can be seen that the same moisture absorption capability can be obtained (the humidity of the air C1 → C3 in the intake passage 510 is similarly 16 g / kg → 9 g / kg). Accordingly, the regeneration temperature can be lowered (the temperature of the exhaust air C7 in the exhaust passage 511 is 54 ° C. → 50 ° C.), and the energy consumption can be extremely reduced.

  FIG. 2B shows the relationship between the temperature in the dehumidification rotor 101 and the vapor pressure. a → b is an operation when the dehumidifying rotor 101 rotates and moves from the intake passage 510 to the exhaust passage 511. Since ultraviolet rays are blocked at this time, the adsorptive power of the dehumidifying rotor 101 is reduced and moisture is released, and the vapor pressure is rapidly increased. b → c is an operation in the exhaust passage 511, and the temperature rises while dehumidifying. c → d is an operation when the dehumidification rotor 101 moves from the exhaust passage 511 to the intake passage 510. Since the ultraviolet ray is irradiated at this time, the photocatalyst is activated and the adsorption force is increased, so that the vapor pressure is rapidly decreased. d → e → a is an operation in the intake passage 510 and absorbs moisture while being cooled.

  Here, the ratio of the area surrounded by a → b → c → d → e shown in FIG. 2B and the area surrounded by a → b → c shown in FIG. It is proportional to the amount of moisture that can be absorbed and released by. From this, it can be seen that the capability of the photocatalytic desiccant air conditioning system according to the present embodiment is greatly improved as compared with the conventional desiccant air conditioning system.

  FIG. 3 is a diagram illustrating an example in which an electric field applying unit is used instead of the light irradiation unit (ultraviolet irradiation device 102). The photocatalyst material can be activated by applying an electric field instead of irradiating with ultraviolet rays as in the case of irradiating light. Therefore, as shown in FIG. 3, both sides and the middle part of the rotor 103 are formed of a conductive material to form electrodes 103a and 103b, and a power source 104 as an electric field applying means is connected. The photocatalytic material may be interposed between the electrodes, or may be applied or attached to the surface of the electrode itself.

FIG. 4 is a diagram showing an apparatus and results of an experiment conducted using photocatalytic silica gel. A photocatalyst silica gel 202 is enclosed in a container 201 having an ultraviolet transmissive top surface, and a gas is introduced from below while irradiating light from above with a fluorescent lamp 203 as a light irradiating means. Stir. The experimental conditions were 400 g of moisture-absorbing photocatalytic silica gel, room temperature of 24 ° C., time of 10 minutes, air flow rate of 2 m ³ / min, and light source fluorescent lamp of 10 W. As a result, as a result of moisture absorption, the humidity 92% decreased to 88%, and about 5 g of moisture was absorbed. Furthermore, when the fluorescent lamp was turned off and the air flow was continued, it was confirmed that 5 g of moisture was released, that is, the increased 5 g was not absorbed by silica gel but was due to an overhumid state due to photocatalysis. I understand.

  Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  INDUSTRIAL APPLICABILITY The present invention can be used as a desiccant air-conditioning system that absorbs and releases moisture by first carrying moisture on a hygroscopic material, and a method for absorbing and releasing moisture.

It is a figure which shows the example of the desiccant air conditioning system using a photocatalytic action. It is a figure which shows the other example of a desiccant air conditioning system. It is a figure which shows the example which replaced with the light irradiation means and used the electric field application means. It is a figure which shows the apparatus and result of the experiment conducted using the photocatalyst silica gel. It is a figure which shows schematic structure of desiccant air conditioning. It is a figure which shows schematic structure of a rotation type total heat exchanger.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Air conditioning system, 101 ... Dehumidification rotor, 102 ... Ultraviolet irradiation apparatus, 103 ... Rotor, 103a, 103b ... Electrode, 104 ... Power supply, 110, 510, 610 ... Inlet passage, 111, 511, 611 ... Exhaust passage, 201 DESCRIPTION OF SYMBOLS ... Container, 202 ... Photocatalyst silica gel, 203 ... Fluorescent lamp, 500 ... Desiccant air conditioning, 501 ... Dehumidification rotor, 502 ... Sensible heat rotor, 503 ... Heater, 600 ... Total heat exchanger, 601 ... Heat exchange rotor

Claims (6)

An element containing a photocatalytic material;
Activating means for activating the photocatalytic material of the element;
A ventilation means for circulating two lines of gas through the element;
By activating the photocatalytic material of the element to absorb moisture from the gas of one system, the element is brought into an overhumid state, and by stopping the activation of the photocatalytic material, the gas of the other system is dehumidified. A photocatalytic desiccant air conditioning system.   2. The photocatalytic desiccant air conditioning system according to claim 1, wherein the activating means is a light irradiation means.   2. The photocatalytic desiccant air conditioning system according to claim 1, wherein the activating means is an electric field applying means.   2. The photocatalytic desiccant air conditioning system according to claim 1, wherein the element includes a hygroscopic material containing a photocatalytic material in a porous, honeycomb-like or fibrous carrier.   A moisture, absorbent material containing a photocatalyst material in a porous, honeycomb-like or fibrous carrier is activated to absorb moisture, and the moisture is released by stopping the activation of the photocatalyst material. Moisture absorption and release method.   The photocatalytic desiccant air conditioning system according to claim 1, wherein the photocatalytic material is titanium oxide.

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