heat exchange device

Abstract

This invention provides a heat exchange device that can be miniaturized, improves energy consumption efficiency, and has superior heat absorption and heating capabilities. [Solution] A heat exchange device comprising a porous material whose pore size changes in response to external stimuli, an absorption and heating section containing a medium that adsorbs and desorbs to the porous material, a housing section housing the absorption and heating section, an external stimulus input unit that applies the external stimulus to the porous material, and a heat exchange channel through which a heat medium that is heated or cooled by heat exchange with the housing section flows, wherein the external stimulus is two or more types of light stimuli with different wavelengths, and the porous material comprises a porous body and a photoisomerized layer containing a photoisomerized compound formed on the surface of the pores of the porous body, wherein a portion of the photoisomerized compound dissolves in the medium when the medium is adsorbed and re-precipitation occurs when the medium is desorbed.

Description

[Technical Field]

[0001] This invention relates to a heat exchange device. [Background technology]

[0002] Conventionally, heat exchange devices that heat or cool an object (space or object) by transferring heat have been widely used. For example, Patent Document 1 below discloses an adsorption type heat pump (desiccant air conditioner) that uses a heat pump that provides a high heat source to vaporize water as a medium and a low heat source to condense the vaporized water, and a desiccant (drying agent) to collect the water. In such adsorption type heat pumps, porous materials such as silica gel and zeolite are generally used as the adsorbent for the desiccant. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-197011 [Overview of the project] [Problems that the invention aims to solve]

[0004] In conventional adsorption heat pumps (desiccant air conditioners), the movement speed of refrigerant molecules, which are the medium in the porous material, is low. Therefore, when the refrigerant molecules evaporate (i.e., absorb heat), the evaporation rate of the refrigerant molecules is low, making it difficult to obtain a sufficient amount of absorbed heat per unit time. One method to promote the evaporation of refrigerant molecules is to raise the temperature of the porous material, but this method requires a heater for heat input, leading to a larger device. In addition, energy is required to operate the heater, so the energy consumption efficiency decreases.

[0005] This invention has been made in view of these circumstances, and aims to provide a heat exchange device that can be miniaturized, improves energy consumption efficiency, and has superior heat absorption and heating capacity. [Means for solving the problem]

[0006] In order to solve the above problems, the inventors of the present invention have been diligently conducting research and have been working on developing a heat exchange device that directly utilizes the latent heat generated by the desorption or adsorption of a medium as cooling or heating by applying a porous material capable of adsorbing and desorbing a medium to the heat absorption and heating section. In the process, they discovered that by using a porous material in which the pore size reversibly changes with two or more types of light stimulation with different wavelengths, and in which a medium is adsorbed and desorbed accordingly, it is possible to efficiently perform heat exchange by utilizing the latent heat generated by the desorption or adsorption of the medium. Furthermore, they discovered that the above problems can be solved by using a porous material having a porous body and a photoisomerized layer containing a photoisomerized compound formed on the surface of the pores of the porous body, wherein a portion of the photoisomerized compound dissolves in the medium when the medium is adsorbed and re-precipitations when the medium is desorbed, and thus completed the present invention.

[0007] In other words, one embodiment of the present invention is a heat exchange device comprising: a porous material whose pore size changes in response to an external stimulus; an absorption and heating section containing a medium that adsorbs and desorbs to the porous material; a housing section housing the absorption and heating section; an external stimulus input unit that applies the external stimulus to the porous material; and a heat exchange channel through which a heat medium that is heated or cooled by heat exchange with the housing section flows, wherein the external stimulus is two or more types of light stimuli with different wavelengths; the porous material comprises a porous body and a photoisomerized layer containing a photoisomerized compound formed on the surface of the pores of the porous body; and a portion of the photoisomerized compound dissolves in the medium when the medium is adsorbed and re-precipitation occurs when the medium is desorbed. [Effects of the Invention]

[0008] According to the present invention, a heat exchange device is provided that can be miniaturized, improves energy consumption efficiency, and has superior heat absorption and heating capacity. [Brief explanation of the drawing]

[0009] [Figure 1]Figure 1 is a diagram showing a heat exchange apparatus according to an embodiment of the present invention. [Figure 2A] Figure 2A is a diagram schematically illustrating a state in which the pore diameter of a porous material changes due to an external stimulus in the heat exchange apparatus according to the embodiment of the present invention, and the medium is adsorbed and desorbed to and from the porous material accordingly. [Figure 2B] Figure 2B is a diagram schematically illustrating the adsorption and desorption of the medium and the accompanying dissolution and re-precipitation of the photoisomerizable compound in the heat exchange apparatus according to the embodiment of the present invention. [Figure 3] Figure 3 is a diagram showing an example of a housing portion in the heat exchange apparatus according to the embodiment of the present invention. [Figure 4] Figure 4 is a diagram showing a heat exchange apparatus according to an embodiment of the present invention. [Figure 5] Figure 5 is a diagram showing a heat exchange apparatus according to an embodiment of the present invention. [Figure 6] Figure 6 is a schematic diagram showing an example of control of the heat exchange apparatus according to the embodiment of the present invention. [Figure 7] Figure 7 is a schematic diagram showing an example of control of the heat exchange apparatus according to the embodiment of the present invention. [Figure 8] Figure 8 is a schematic diagram showing an example of control of the heat exchange apparatus according to the embodiment of the present invention. [Figure 9A] Figure 9A is a water vapor adsorption and desorption isotherm of the porous material produced in Example 1 in the case where ultraviolet light irradiation was not performed (OFF-OFF) and in the case where ultraviolet light irradiation was performed only during the desorption process after saturated adsorption (OFF-ON). [Figure 9B] Figure 9B is a water vapor adsorption and desorption isotherm of the porous materials produced in Comparative Example 1, Example 1, and Example 2 in the case where ultraviolet light irradiation was not performed (OFF-OFF) and in the case where ultraviolet light irradiation was performed only during the desorption process after saturated adsorption (OFF-ON). [Mode for Carrying Out the Invention]

[0010] The embodiments of the present invention described above will be explained below with reference to the drawings, but the technical scope of the present invention should be determined based on the claims and is not limited to the following forms. Note that the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios.

[0011] One embodiment of the present invention is a heat exchange device comprising: a porous material whose pore size changes in response to an external stimulus; an absorption and heating section containing a medium that adsorbs and desorbs to the porous material; a housing section housing the absorption and heating section; an external stimulus input unit that applies the external stimulus to the porous material; and a heat exchange channel through which a heat medium that is heated or cooled by heat exchange with the housing section flows, wherein the external stimulus is two or more types of light stimuli with different wavelengths; the porous material comprises a porous body and a photoisomerized layer containing a photoisomerized compound formed on the surface of the pores of the porous body, wherein a portion of the photoisomerized compound dissolves in the medium when the medium is adsorbed and re-precipitation occurs when the medium is desorbed. According to this embodiment, miniaturization is possible, energy consumption efficiency can be improved, and a heat exchange device superior in terms of absorption and heating capacity is provided.

[0012] 《First Embodiment》 Figure 1 is a schematic diagram showing a heat exchanger 200 according to one embodiment of the present invention. As shown in Figure 1, the heat exchanger 200 includes an absorption / heating section 11 containing a porous material 1 whose pore size changes in response to external stimuli (two or more types of light stimuli with different wavelengths) and a medium 3 that adsorbs and desorbs to the porous material 1, and a housing section 100 that houses the absorption / heating section 11. Furthermore, the heat exchanger 200 includes an external stimulus input unit 600 that applies external stimuli to the porous material 1, and an airflow path 150 (an example of the "heat exchange flow path" in the present invention) which serves as an air conditioning duct through which air (an example of the "heat transfer medium" in the present invention) flows. The blown air is cooled or heated by heat exchange with the housing section 100, and passes through the airflow path 150 as cold air or warm air. Since such a heat exchanger 200 does not require heat input, it can be miniaturized and its energy consumption efficiency (COP) can be improved.

[0013] (Heat-absorbing and heat-generating section) The heat-absorbing and heat-generating section 11 includes a porous material 1 whose pore diameter changes in response to external stimuli, and a medium 3 that is detachably adsorbed to the pore walls of the porous material. The heat-absorbing and heat-generating section 11 may be either a heat-absorbing and heat-generating material that absorbs heat as the pore diameter shrinks and generates heat as the pore diameter expands, or a heat-absorbing and heat-generating material that generates heat as the pore diameter shrinks and absorbs heat as the pore diameter expands.

[0014] The porous material contained in the heat-absorbing and heat-generating section 11 is a porous material whose pore size changes in response to two or more light stimuli of different wavelengths. The porous material comprises a porous body and a photoisomerized layer containing a photoisomerized compound formed on the surface of the pores of the porous body. The porous material, for example, undergoes a reversible change in pore size in response to two light stimuli of different wavelengths.

[0015] The porous material is not particularly limited as long as it can adsorb and desorb a medium within its pores, but it is preferably a nanoporous material. "Nanoporous" means having multiple nanoscale pores. Nanoscale pores are preferably micropores or mesopores with a diameter of 0.5 to 100 nm, more preferably 0.7 to 50 nm, and even more preferably 0.7 to 6 nm. The IUPAC (International Union of Pure and Applied Chemistry) defines pores with a diameter of 2 nm or less as micropores, pores with a diameter of 2 to 50 nm as mesopores, and pores with a diameter of 50 nm or more as macropores.

[0016] In particular, it is preferable to use a mesoporous material having mesopores with a diameter of 2 to 50 nm as the porous body. The material of the porous body is not particularly limited, and examples include silica and alumina, but silica is preferred. In particular, it is preferable to use mesoporous silica as the porous body.

[0017] The mesoporous silica used in this invention is a material made of silicon dioxide (silica) and has uniform and regular mesopores with a diameter of 2 to 50 nm. In the preparation of mesoporous silica, a surfactant micelle is generally used as a template (structure directing agent), and a regular silica skeleton is formed by coating the micelle with silica components. Further firing removes the internal surfactant, leaving only the silica skeleton and forming regular mesopores. Various types have been synthesized by changing the type of surfactant, and the MCM series and SBA series are known. For example, MCM-41, aluminosilicate MCM-41, HMS, MCM-48, SBA-15, SBA-16, FSM-16, etc. can be cited. Commercially available mesoporous silica may also be used.

[0018] The pore size (average pore size) of mesoporous silica is not particularly limited, but is preferably 2 to 10 nm, and more preferably 2 to 5 nm. The shape and pore size (average pore size) of porous materials such as mesoporous silica can be confirmed by transmission electron microscopy (TEM) observation of the surface and cross-section of a thin film containing the porous material. The pore size (average pore size) of porous materials such as mesoporous silica may also be determined by nitrogen adsorption / desorption measurement. The BET specific surface area of ​​mesoporous silica is not particularly limited, but for example, 200 to 2500 m². 2 The value is / g. The pore volume (total pore volume) of mesoporous silica is not particularly limited, but for example, 0.2-4 cm³ is also acceptable. 3 The value is / g, preferably 0.2-1cm 3 The value is / g. The BET specific surface area and pore volume of porous materials such as mesoporous silica can be determined by nitrogen adsorption / desorption measurement. Mesoporous silica may also have surface-modified pore walls.

[0019] In this embodiment of the heat exchanger, the porous material has a photoisomerized layer containing a photoisomerized compound formed on the surface of the pores of the porous body. In this case, the means for forming the photoisomerized layer containing the photoisomerized compound is not particularly limited, as long as the photoisomerized compound can be introduced to the surface of the pores, and when a medium is adsorbed onto the porous material, a portion of the photoisomerized compound dissolves in the medium, and when the medium is desorbed, the photoisomerized compound reprecipitates on the surface of the pores. For example, the photoisomerized layer can be formed by physically adsorbing the photoisomerized compound onto the surface of the pores (the surface of the pore walls) of a porous body such as mesoporous silica by methods such as solution impregnation or vacuum impregnation of the photoisomerized compound. Here, the ratio of the volume of the photoisomerized compound present in the pores to the pore volume of the porous body is not particularly limited, as long as it is greater than 0 and less than 1. The above ratio is preferably 0.1 to 0.9, more preferably 0.2 to 0.8, even more preferably 0.3 to 0.7, and even more preferably 0.4 to 0.6, when no medium is adsorbed. Within this range, the heat exchange efficiency can be further improved. The above ratio can be estimated by the method described in the following examples.

[0020] Photoisomerized compounds undergo stereoisomerization or structural isomerization (cis-trans isomerization, photo-ring opening reaction, etc.) upon light irradiation. The photoisomerized compound is not particularly limited as long as it can form a photoisomerized layer containing the photoisomerized compound on the surface of the pores of a porous material, and a portion of it dissolves in the medium upon adsorption and reprecipitations upon desorption of the medium. Examples of photoisomerized compounds include compounds having an azobenzene structure (azobenzene compounds), compounds having a spiropyran structure, compounds having a stilbene structure, and compounds having a diarylethene structure. Of these, compounds having an azobenzene structure (azobenzene compounds) are particularly preferred because they can more effectively change the pore size of the porous material through photoisomerization.

[0021] Azobenzene compounds isomerize from the trans isomer to the cis isomer upon irradiation with ultraviolet light, and from the cis isomer to the trans isomer upon irradiation with visible light. For example, in the case of azobenzene, photoisomerization occurs as shown in the following formula.

[0022] [ka]

[0023] As an azobenzene compound, for example, the compound represented by the following chemical formula (1) can be used:

[0024] [ka]

[0025] In the above chemical formula (1), R 1 and R 2 Each of these is independently a halogen atom, a hydroxyl group, an amino group, a cyano group, a nitro group, a carboxyl group, a formyl group, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C1-C6 alkylamino group, a C2-C6 dialkylamino group, a C2-C6 acyl group, or a C2-C6 alkoxycarbonyl group, and each of m1 and m2 is independently an integer from 0 to 5.

[0026] Examples of media include water or alcohol. Examples of alcohols include methanol or ethanol. These media can be fluid media, that is, in the form of liquids, gases, or mixtures of liquids and gases.

[0027] Figure 2A schematically shows how, in this embodiment of heat exchanger, the pore size of the porous material 1 changes due to external stimuli, and how the medium 3 is adsorbed and desorbed onto the porous material as a result. As shown in Figure 2A(a), in the porous material 1, the azobenzene compound, which is a photoisomerized compound, is adsorbed in a stable trans state on the surface of the inner wall 7 of the pores 4 in the porous body 2 with a pore size D, forming a photoisomerized layer 6, and the pore size of the porous material 1 becomes B. When the medium 3 is introduced into the pores 4 of the porous material 1 as shown by the arrows, the medium 3 is adsorbed on the inner wall 7 of the pores 4 in a liquid state, and a meniscus 5 is formed due to surface tension. When ultraviolet light (UV) is irradiated onto the porous material 1, as shown in Figure 2A(b), the azobenzene compound is photoisomerized into the cis state. However, since the molecular length Lc of the cis state is smaller than the molecular length Lt of the trans state, the pore size A of the porous material 1 becomes larger than the pore size B before UV irradiation. Consequently, the meniscus of the adsorbed medium 3 collapses, and medium 3 vaporizes and desorbs, as indicated by the arrow. In other words, rapid desorption of medium 3 occurs due to a change in pore size caused by light stimulation. When the porous material 1 is irradiated with visible light (Vis), the azobenzene compound photoisomerizes from the cis isomer to the trans isomer, reducing the pore size to B, which allows for the adsorption of medium 3. In this case, if medium 3 is a refrigerant such as water or alcohol, the heat-absorbing and heat-removing portion generates heat upon adsorption of the medium and absorbs heat upon desorption of the medium.

[0028] In the heat absorption and heating section of this heat exchanger, a portion of the photoisomerized compound dissolves in the medium during adsorption and re-precipitations during desorption of the medium. Figure 2B schematically shows the adsorption and desorption of the medium 3 and the associated dissolution and re-precipitation of the photoisomerized compound. When the medium is a refrigerant, in the heat generation process, the medium 3 is adsorbed onto the inner wall 7 of the porous body 2 (1. Adsorption of the medium), and as the adsorption of the medium progresses, a portion of the photoisomerized compound dissolves in the medium 3 (2. Dissolution of the photoisomerized compound). This can increase the volume that the medium 3 can adsorb in the pores 4. In other words, the utilization rate of the pore volume can be improved. As a result, the amount of adsorption of the medium 3 increases, and the heat generation performance can be improved. In the heat absorption process, as the medium 3 is desorbed, the photoisomerized compound that was dissolved in the medium 3 re-precipitations onto the inner wall 7 of the porous body 2 (3. Re-precipitation of the photoisomerized compound). Subsequently, light stimulation isomerizes the photoisomerized compound, increasing the pore diameter of pore 4, which causes the meniscus of medium 3 to collapse, resulting in rapid desorption of medium 3 (4. Meniscus collapse). By changing the pore diameter with light stimulation in this way, a greater amount of cooling can be obtained by causing rapid desorption of the medium. However, if the photoisomerized compound does not dissolve in medium 3, such as when the photoisomerized compound is completely immobilized on the inner wall 7 of pore 4, the utilization rate of the pore volume cannot be sufficiently increased, and therefore sufficient exothermic performance cannot be obtained. On the other hand, if the photoisomerized compound is completely dissolved in medium 3, no change in pore diameter is obtained with light stimulation, and rapid desorption of medium 3 does not occur, so sufficient endothermic performance cannot be obtained.

[0029] In a porous material, in order to perform control such that part of the photoisomerizable compound dissolves in the medium during adsorption of the medium and re-precipitates during desorption of the medium, a method of controlling the binding force between the pore wall surface of the porous body and the photoisomerizable compound may be mentioned. For example, a method of physically adsorbing the photoisomerizable compound onto the pore wall surface of the porous body with an appropriate intermolecular force can be used. For example, the photoisomerizable compound such as an azobenzene compound can be physically adsorbed into the pores of the porous body by a solution impregnation method or the like, and at this time, the magnitude of the binding force (intermolecular force) can be adjusted by changing the material of the porous body and the type of the photoisomerizable compound. When the porous body is mesoporous silica, the pore wall surface of the mesoporous silica has silanol groups (-SiOH), and when the photoisomerizable compound has a substituent such as a carboxyl group or a hydroxy group, a hydrogen bond can be formed with the silanol group, so that the binding force can increase. In addition, since the van der Waals force is proportional to the molecular weight, when the photoisomerizable compound has a substituent such as a methyl group, the van der Waals force becomes larger than that in the case where the photoisomerizable compound does not have the substituent, and the binding force with the pore wall surface of the mesoporous silica can increase. That part of the photoisomerizable compound dissolves in the medium during adsorption of the medium and re-precipitates during desorption of the medium can be confirmed by medium adsorption / desorption measurement as described in Examples later.

[0030] In one embodiment, when the porous body is mesoporous silica and the medium is water, the photoisomerizable compound is, in the above chemical formula (1), R 1 and R 2 are each independently a hydroxy group, a carboxy group, or an alkyl group having 1 to 3 carbon atoms, m1 and m2 are each independently an integer of 0 to 2, and m1+m2 is an integer of 1 to 4. In a preferred embodiment, R 1 and R 2 are each present at the meta position or the para position relative to the N=N bond. Preferably, the photoisomerizable compound is 3,3'-dimethylazobenzene or 4-(phenylazo)benzoic acid.

[0031] (External Stimulus Input Unit) The external stimulus input unit may have a light source for applying light stimulation. The specific form of the external stimulus unit is not particularly limited. The light source is not particularly limited, and known light sources such as monochromatic lasers, light-emitting diodes (LEDs), low-pressure mercury lamps, high-pressure mercury lamps, xenon lamps, and metal halide lamps can be used. The wavelength of the irradiated light is also not particularly limited and can be set according to the type of photoisomerized compound. For example, ultraviolet light in the range of 280-400 nm and visible light in the range of 405-600 nm can be used in combination. The amount of irradiated light is also not particularly limited and can be set as appropriate.

[0032] In the embodiment shown in Figure 1 above, the external stimulus input unit 600 is shown as being located inside the heat exchange channel 150 and outside the housing section 100. However, the position of the external stimulus input unit is not particularly limited. For example, it may be located outside the heat exchange channel or inside the housing section 100. When the external stimulus input unit 600 is located outside the housing section 100 or the heat exchange channel 150, it is preferable to provide light-transmitting parts (not shown), such as windows or slits, on the walls of the housing section 100 or the heat exchange channel 150 to secure the optical path.

[0033] (Detention area) The materials used to constitute the housing 100 are not particularly limited, but high thermal conductivity materials such as metals can be used. Among these, aluminum, iron, nickel, gold, silver, copper, alloys thereof, and stainless steel can be preferably used.

[0034] The inner wall of the housing preferably reflects incident light as an external stimulus. In this way, incident light that has passed through the porous material can be reflected by the inner wall located in the extension of the incident light and reintroduced into the porous material, thus efficiently utilizing the incident light. As a result, the efficiency of heat exchange can be improved. Preferably, the inner wall of the housing has a reflectance of 70% or more to incident light, and more preferably 80% or more. For example, aluminum has a reflectance of 80% or more in the wavelength range of 310 to 800 nm, and silver has a reflectance of 80% or more in the wavelength range of 360 to 800 nm. High efficiency can be achieved by using such materials for the inner wall of the housing.

[0035] In a preferred embodiment, the external stimuli are two types of light stimuli with wavelengths λ1 and λ2, respectively. When the reflectance of the inner wall of the housing for wavelength λ1 is Rλ1 and the reflectance for wavelength λ2 is Rλ2, the housing is a container in which the reflectance of the inner wall on the extension of the incident light of wavelength λ1 satisfies Rλ1≧Rλ2, and the reflectance of the inner wall on the extension of the incident light of wavelength λ2 satisfies Rλ2≧Rλ1. For example, if wavelength λ1 is ultraviolet light of 280-400 nm and wavelength λ2 is visible light of 405-600 nm, using aluminum for the inner wall on the extension of the incident light of wavelength λ1 satisfies the reflectance Rλ1≧Rλ2, and using silver for the inner wall on the extension of the incident light of wavelength λ2 satisfies the reflectance Rλ2≧Rλ1. This allows for more efficient use of each type of light in both endothermic and exothermic reactions. Therefore, the efficiency of the heat exchanger can be further improved.

[0036] Furthermore, it is preferable that irregularities are formed on the surface of the inner wall of the housing, which lies in the extension of the incident light. This allows the incident light to be diffusely reflected off the surface of the inner wall, thereby improving efficiency. If the external stimuli are two or more types of light stimuli with different wavelengths, it is even more preferable that irregularities are formed on the surface of the inner wall, which lies in the extension of each incident light.

[0037] In one embodiment, the surface of the inner wall of the housing, which lies in the extension of the incident light, is convex, like the surface of a convex lens. Preferably, the center of the inner wall is located in the extension of the incident light, and the center of the inner wall is convex. As a result, a portion of the incident light can pass through the porous material and be reflected and diffused by the convex surface, thereby increasing the area of ​​the region illuminated by light when it enters the porous material again. As a result, higher efficiency can be achieved. When the external stimulus is two types of light stimuli with different wavelengths, the above configuration is preferable for each incident light (light stimulus). In another embodiment, a concave light-transmitting material, such as a concave lens, may be placed between the external stimulus input unit and the porous material. As a result, the incident light as an external stimulus is diffused, and the area of ​​the region illuminated by light when it enters the porous material can be increased. As a result, higher efficiency can be achieved. Here, the concave light-transmitting material only needs to be in the optical path of the incident light, and may be placed inside the housing or outside the housing. Also, when the external stimulus is two types of light stimuli with different wavelengths, the above configuration is preferable for each incident light (light stimulus).

[0038] In one embodiment, the housing has an inner wall surface that is concave, like the surface of a concave lens, on the extension of the incident light. Preferably, the center of the inner wall is on the extension of the incident light, and the center of the inner wall is concave. As a result, a portion of the incident light can pass through the porous material, be reflected by the concave surface, and be focused into the porous material before being incident into the porous material again. Therefore, the energy density of the irradiated light increases, and efficiency can be improved. When the external stimulus is two types of light stimuli with different wavelengths, the above configuration is preferable for each incident light (light stimulus). In another embodiment, a convex light-transmitting material, such as a convex lens, may be placed between the external stimulus input unit and the porous material. As a result, the incident light as an external stimulus is focused into the porous material, increasing the energy density of the irradiated light and improving efficiency. Here, the convex light-transmitting material only needs to be on the optical path of the incident light, and may be placed inside or outside the housing. Also, when the external stimulus is two types of light stimuli with different wavelengths, the above configuration is preferable for each incident light (light stimulus).

[0039] (Heat exchange channel) The heat exchange channel is not particularly limited as long as it can circulate a heat transfer medium that is heated or cooled by heat exchange with the housing. The heat transfer medium can be, for example, air. The heat exchange channel can be, for example, an air conditioning duct. In a preferred embodiment, the housing is placed inside the air conditioning duct, which is the heat exchange channel. This allows heat exchange to occur between the housing and the air flowing through the heat exchange channel.

[0040] Furthermore, as will be described later, it is preferable that the housing unit is movable within the heat exchange channel, and that heat exchange is performed while the housing unit moves within the heat exchange channel. Moreover, it is even more preferable that the heat exchange device of this embodiment has multiple housing units, and that heat exchange is performed sequentially while these housing units move within the heat exchange channel. This improves the heat exchange efficiency.

[0041] Furthermore, the heat exchange channel is not limited to the form of a duct. For example, the heat exchange channel may be a heat-conducting conduit through which a heat transfer medium can flow, and the conduit may be arranged in contact with the outer wall of the housing. This allows heat exchange to occur between the housing and the heat transfer medium flowing through the heat exchange channel.

[0042] (Means for adjusting media pressure) In this embodiment of the heat exchanger, the containment section may be sealed, but it may further have a medium pressure adjustment means connected to the containment section for adjusting the pressure of the medium in the containment section by controlling the amount of medium in the containment section. The medium pressure adjustment means is not particularly limited and may be a medium source or a vacuum pump for supplying or removing the medium from the containment section. Figure 3 shows an example of a containment section 100 in this embodiment of the heat exchanger. In Figure 3, a medium pressure adjustment means 20 is connected to the containment section 100. The medium pressure adjustment means 20 includes a medium tank 21 for storing the medium 3 and a medium flow path 22. A pump P is connected to the medium flow path 22. The pump P supplies the medium 3 to the containment section 100 to increase the pressure of the medium 3 in the containment section 100, and removes the medium 3 from the containment section 100 to decrease the pressure of the medium 3 in the containment section 100. In addition to applying or stopping external stimuli, adjusting the pressure of the medium 3 in the containment section 100 allows for more efficient adsorption and desorption of the medium, further improving its heat absorption and heat dissipation performance.

[0043] (Heat conduction part) In the heat exchanger 200, the housing 100 may further include a heat-absorbing / heat-generating section 11 and a heat-conducting section (not shown) that directly or indirectly contacts the heat-absorbing / heat-generating section 11 to conduct heat from the heat-absorbing / heat-generating section 11. The housing may have multiple heat-conducting sections. For example, multiple heat-conducting sections may sandwich the heat-absorbing / heat-generating section 11 from both sides in the thickness direction. The heat-conducting sections are, for example, arranged inside the housing 100 and directly or indirectly contact the housing 100 to conduct heat from the heat-absorbing / heat-generating section 11 to the housing 100.

[0044] 《Second Embodiment》 In a preferred embodiment of the present invention, the heat exchange device is configured such that the housing is movable within the heat exchange channel, and heat exchange is performed while the housing moves within the heat exchange channel. The heat exchange channel comprises a cold air channel having a cold air generating section in which the heat transfer medium is cooled by heat absorption by the heat absorption section, and a hot air channel having a hot air generating section in which the heat transfer medium is heated by heat generation by the heat absorption section, and at least one external stimulus input unit is disposed in at least one of the hot air generating section and the cold air generating section.

[0045] Figure 4 shows a heat exchanger 200A according to the second embodiment. As shown in Figure 4, the heat exchanger 200A comprises a plurality of containment units 100, a cold air generating unit 201, and a hot air generating unit 202. The cold air generating unit 201 has a cold air passage 1501 through which cold air is generated when air 152 (an example of the "heat transfer medium" of the present invention) is cooled by the heat absorbed by the containment units 100. The hot air generating unit 202 has a hot air passage 1502 through which hot air is generated when air 152 is heated by the heat generated by the containment units 100. Air is introduced, for example, from an inlet P11 into the cold air passage 1501 and the hot air passage 1502, and the cooled air and heated air 152 are mixed as appropriate and discharged from an outlet P21 and introduced into the vehicle compartment. The ends of the semicircularly arranged cold air passage 1501 and the ends of the semicircularly arranged hot air passage 1502 are connected to each other, forming an annular (circular in this embodiment) air passage 150. In Figure 4, the right side of the circle is the cold air passage 1501, and the left side of the circle is the hot air passage 1502.

[0046] The air passage 150 of the heat exchanger 200A according to this embodiment (an example of the "heat exchange passage" of the present invention) is composed of a cold air passage 1501 and a hot air passage 1502. The heat exchanger 200A may further include a blower (not shown).

[0047] In a heat exchanger 200A according to one embodiment of the present invention, a plurality of housing units 100 are arranged at equal intervals from each other inside an annular air passage 150 and move clockwise or counterclockwise. As a result, the housing units 100 move alternately within the cold air passage 1501 and the hot air passage 1502.

[0048] In the heat exchanger shown in Figure 4, external stimulus input units 601 and 602 are placed one each in the cold air generation section 201 and the hot air generation section 202 of the heat exchange flow path 150. As a result, multiple containment sections 100 move between the cold air flow path 1501 and the hot air flow path 1502, receiving external stimuli sequentially from the external stimulus input units 601 and 602. This increases the number of heat absorption and heating sections 11 that can receive external stimuli per unit time, potentially improving the heat absorption and heating output. Furthermore, it increases design flexibility and enables the heat exchanger to be made more compact. In this embodiment, if the heat-absorbing and heat-generating section 11 contains a porous material whose pore diameter expands in response to external stimulation 1 from external stimulation input unit 601 and contracts in response to external stimulation 2 from external stimulation input unit 602, and generates heat upon adsorption of a medium and absorbs heat upon desorption, the porous material inside the housing section 100 receives external stimulation 1 (irradiation with ultraviolet light) from external stimulation input unit 601 near the inlet of the cold air passage 1501. As a result, the heat-absorbing and heat-generating section 11 absorbs heat, and the housing section 100 exchanges heat with the air 152 in the cold air passage 1501, cooling the air 152. Consequently, cold air is generated in the cold air generating section 201. The cold air generated in the cold air passage 1501 is exhausted through the outlet P21. In addition, the porous material inside the housing section 100 receives external stimulation 2 (irradiation with visible light) from external stimulation input unit 602 near the inlet of the warm air passage 1502. As a result, the heat absorption and heating section 11 generates heat, and the containment section 100 exchanges heat with the air 152 in the hot air passage 1502, warming the air 152. Consequently, hot air is generated in the hot air generation section 202. The hot air generated in the hot air passage 1502 is exhausted from the outlet P21.

[0049] The heat exchanger 200A can be miniaturized and its energy efficiency (COP) can be improved. Furthermore, separating the cold air generation unit 201 and the hot air generation unit 202 can improve the heat absorption and heating output. Additionally, temperature control at the air outlet 152 becomes easier.

[0050] In the heat exchange device of this embodiment, the housing unit 100 can exchange heat with a substance (for example, air) outside the housing unit 100, using the heat-absorbing or heat-generating heat-absorbing / heat-generating unit 11 as a heat source. In the heat-absorbing / heat-generating unit 11, external stimuli, rather than heat input from a heater, become the input energy. Therefore, the heat exchange device 200A can improve its energy consumption efficiency (COP: Coefficiency Of Performance). Furthermore, since the heat exchange device 200A does not require a heater for heat input, it can be miniaturized.

[0051] In the heat exchanger 200A described above, the drive mechanism for moving the housing section 100 is not particularly limited. For example, a belt conveyor mechanism (not shown) that moves the housing section 100 when it is operated with the housing section 100 positioned on the upper surface may be used, but is not limited thereto. The operating speed of the drive mechanism may be appropriately set according to the heat absorption rate and heat generation rate in the heat absorption and heat generation section. The belt conveyor mechanism may be a multi-section belt conveyor mechanism divided into multiple belt conveyors. This allows for, for example, separate control of the movement speed of the housing section 100 during heat absorption and heat generation, enabling more efficient heat exchange.

[0052] 《Third Embodiment》 In a preferred embodiment of the present invention, the heat exchange device comprises a stimulus-responsive unit that includes the housing and the external stimulus input unit, and the stimulus-responsive unit is movable within the heat exchange channel, and heat exchange is performed while the stimulus-responsive unit moves within the heat exchange channel.

[0053] Figure 5 shows a heat exchanger 200B according to the third embodiment. The heat exchanger shown in Figure 5 is similar to the embodiment shown in Figure 4, except that instead of arranging at least one external stimulus input unit 601, 602 in the hot air generation section or cold air generation section, external stimulus input units 603, 604 are provided as a stimulus-responsive unit 700 combined with the housing section 100, and are movable inside the heat exchange flow path. That is, as shown in Figure 5, the heat exchanger 200B comprises a housing section 100 and a plurality of stimulus-responsive units 700 each comprising external stimulus input units 603, 604. The plurality of stimulus-responsive units 700 are arranged at equal intervals from each other inside the annular air flow path 150 and move clockwise or counterclockwise. With this configuration, the timing and duration of applying external stimuli can be controlled to adjust according to the rate at which the pore size of the porous material changes and the heat transfer rate from the heat absorption / heating section. As a result, the heat absorption / heating output can be improved. In addition, since the external stimulus input units can be built into the housing section, the device can be miniaturized.

[0054] 《Example of heat exchanger control 1》 Referring to Figure 6, an example of control of a heat exchanger according to one embodiment of the present invention will be described. In the embodiment shown in Figure 6, the heat exchanger has an absorbent / heat-generating section inside the housing section, and the absorbent / heat-generating section has a porous material having a photoisomerized layer in which an azobenzene compound, which is a photoisomerized compound, is adsorbed on the inner wall surface of the pores of a mesoporous silica, which is a porous body, and water as a medium. As shown in Figure 6(a), the pore diameter of the porous material reversibly changes from B to A by irradiation with ultraviolet light (external stimulus 1), and reversibly changes from A to B by irradiation with visible light (external stimulus 2), and A > B. At this time, water, which is the medium, is adsorbed onto the porous material when the pore diameter is A (large), the pore diameter is changed from A (large) to B (small) by visible light, and further the pore diameter is changed from B (small) to A (large) by irradiation with ultraviolet light, thereby desorbing the medium (water).

[0055] The specific form of the heat exchanger for such control is not particularly limited, but one example is shown in Figure 6(b). In the heat exchanger shown in Figure 6(b), the visible light source (Vis) and ultraviolet light source (UV), which are external stimulus input units, are arranged one by one in the cold air generation section 201 of the heat exchange channel 150, starting from the upstream of the airflow. Multiple containment sections 100 are arranged at equal intervals from each other inside the annular air channel 150 and move alternately between the cold air channel and the hot air channel in a counterclockwise direction. In this case, the pressure of the medium 3 in the containment section 100 is not particularly limited, but it is preferable to control it so that it is relatively low when the containment section 100 is moving through the cold air channel 1501, and relatively high (for example, to a pressure near the saturated vapor pressure) when the containment section 100 is moving through the hot air channel 1502. The pressure of the medium 3 in the containment section 100 may be adjusted so that it increases as the containment section 100 moves through the warm air passage 1502 after exiting the cold air passage 1501 and entering the warm air passage 1502, and decreases as it moves through the cold air passage after exiting the warm air passage 1502 and entering the cold air passage 1501. When the containment section 100 moves through the warm air passage 1502, the heat-absorbing and heat-generating section located inside the containment section 100 adsorbs the medium in the porous material in the cis state of the azobenzene compound (the state with a pore size of A (large), state (i) in Figure 6). Then, heat is generated as the medium is adsorbed, and in the containment section 100, heat exchange occurs with the air 152 introduced into the warm air passage 1502 from the direction of the white arrow, generating warm air. When the containment section 100 enters the cold air channel 1501, visible light is irradiated onto the porous material, causing the azobenzene compound to become the trans isomer and the pore size to become B (small) (state (ii) in Figure 6). Subsequently, ultraviolet light is irradiated, causing the azobenzene compound to become the cis isomer again and the pore size to expand to A (state (iii) in Figure 6), resulting in rapid desorption of the medium. The heat absorption and heating section then absorbs heat as the medium desorbs, and in the containment section 100, it exchanges heat with the air 152 introduced into the cold air channel 1501 from the direction of the white arrow, generating cold air. This control allows the medium to be adsorbed in a state with a large pore size (large pore volume), increasing the amount of medium that can be adsorbed by the porous material and thus increasing the amount of heat of adsorption. As a result, the amount of heat generated can be improved.

[0056] 《Example of heat exchanger control 2》 Referring to Figure 7, another example of the control of a heat exchanger according to one embodiment of the present invention will be described. In the embodiment shown in Figure 7, the configuration of the heat absorption and heating section is the same as described above. In the configuration shown in Figure 7, as shown in Figure 7(a), water, which is the medium, is adsorbed onto a porous material when the pore diameter is B (small), and the medium (water) is desorbed by changing the pore diameter from B (small) to A (large) by irradiation with ultraviolet light (external stimulus 1).

[0057] The specific form of the heat exchanger for such control is not particularly limited, but one example is shown in Figure 7(b). In the heat exchanger shown in Figure 7(b), one visible light source (Vis), which is an external stimulus input unit, is placed in the hot air generation section 202 of the heat exchange channel 150, and one ultraviolet light source (UV) is placed in the cold air generation section 201 of the heat exchange channel 150. Multiple containment units 100 are arranged at equal intervals from each other inside the annular air channel 150, and move alternately between the cold air channel and the hot air channel in a counterclockwise direction. In this case, the pressure of the medium 3 in the containment unit 100 is not particularly limited, but it is preferable to control it so that it is relatively low when the containment unit 100 is moving in the cold air channel 1501, and relatively high (for example, to a pressure near the saturated vapor pressure) when the containment unit 100 is moving in the hot air channel 1502. The pressure of the medium 3 in the containment section 100 may be adjusted so that it increases as the containment section 100 moves through the warm air passage 1502 after exiting the cold air passage 1501 and entering the warm air passage 1502, and decreases as it moves through the cold air passage after exiting the warm air passage 1502 and entering the cold air passage 1501. When the containment section 100 moves through the warm air passage 1502, the heat-absorbing and heat-generating section located inside the containment section 100, upon irradiation with visible light, causes the azobenzene compound in the porous material to become a trans isomer (a state with a pore size of B (small)) and adsorb the medium. Then, heat is generated as the medium is adsorbed, and in the containment section 100, heat exchange occurs with the air 152 introduced into the warm air passage 1502 from the direction of the white arrow, generating warm air. When the containment section 100 enters the cold air channel 1501, ultraviolet light is irradiated onto the porous material, causing the azobenzene compound to become the cis isomer, increasing the pore size to A (large), and resulting in rapid desorption of the medium. The heat absorption and heating section then absorbs heat as the medium desorbs, and in the containment section 100, it exchanges heat with the air 152 introduced into the cold air channel 1501 from the direction of the white arrow, generating cold air. This control method allows the medium to be adsorbed while the pore size is small, resulting in rapid filling of the pores by micropore filling. As the adsorption rate of the medium increases, the heat output can be improved.

[0058] 《Example 3 of heat exchanger control》 Referring to Figure 8, another example of the control of a heat exchanger according to one embodiment of the present invention will be described. In the embodiment shown in Figure 8, the configuration of the heat absorption and heating section is the same as described above. In the configuration shown in Figure 8, as shown in Figure 8(a), water, which is the medium, is adsorbed onto a porous material with a pore diameter of B (small), and the pore diameter is changed from B (small) to A (large) by irradiation with ultraviolet light (external stimulus 1). Then, the pore diameter is changed from A (large) to B (small) by irradiation with visible light (external stimulus 2), and further, the pore diameter is changed from B (small) to A (large) by irradiation with ultraviolet light (external stimulus 1) to desorb the medium.

[0059] The specific form of the heat exchanger for such control is not particularly limited, but one example is shown in Figure 8(b). In the heat exchanger shown in Figure 8(b), the visible light source (Vis), which is an external stimulus input unit, is placed one each near the inlet and outlet of the cold air flow path 1501 in the cold air generation section 201 of the heat exchange flow path 150. The ultraviolet light source (UV) is placed one each downstream of the visible light source in the cold air flow path 1501 in the hot air generation section 202 and the cold air generation section 201 of the heat exchange flow path 150. Multiple housing sections 100 are arranged at equal intervals from each other inside the annular air flow path 150 and move alternately between the cold air flow path and the hot air flow path in a counterclockwise direction. In this case, the pressure of the medium 3 in the containment section 100 is not particularly limited, but it is preferable to control it so that it is relatively low when the containment section 100 is moving through the cold air passage 1501, and relatively high (for example, to a pressure near the saturated vapor pressure) when the containment section 100 is moving through the hot air passage 1502. The pressure of the medium 3 in the containment section 100 may be adjusted so that it increases as the containment section 100 moves through the hot air passage 1502 after exiting the cold air passage 1501 and entering the hot air passage 1502, and then decreases as it moves through the cold air passage after exiting the hot air passage 1502 and entering the cold air passage 1501. When the containment section 100 moves within the hot air passage 1502, the heat-absorbing and heat-generating section placed inside the containment section 100 starts adsorbing the medium in the porous material in which the azobenzene compound is in the trans isomer state (the state with a pore size of B (small), state (i) in Figure 8). Subsequently, irradiation with ultraviolet light causes the azobenzene compound to become the cis isomer (with a large pore size of A, state (ii) in Figure 8), and in this state, the adsorption of the medium proceeds. As the medium is adsorbed, heat is generated, and in the containment section 100, heat exchange occurs with the air 152 introduced into the hot air channel 1502 from the direction of the white arrow, generating hot air. When the containment section 100 enters the cold air channel 1501, visible light is irradiated onto the porous material, causing the azobenzene compound to become the trans isomer and the pore size to become small (state (iii) in Figure 8). Then, irradiation with ultraviolet light causes the azobenzene compound to become the cis isomer again and the pore size to expand to A (state (iv) in Figure 8), resulting in rapid desorption of the medium.By controlling the process in this way, the medium is adsorbed while the pore size is small, and then the pore size is expanded. This results in both an increased adsorption rate and a larger adsorption capacity, potentially improving both the heat output and the amount of heat generated.

[0060] Although embodiments of the heat exchange device according to the present invention have been described in detail above, the embodiments described with reference to the drawings are merely examples, and the present invention may be implemented by making appropriate modifications within the scope of the technical idea of ​​the invention described in the claims.

[0061] <Examples of application> The heat exchangers 200, 200A, and 200B described above are applicable, for example, to air conditioning systems (vehicle air conditioning systems) installed in vehicles.

[0062] Furthermore, the following items are also included within the scope of the present invention: Item 1: A porous material whose pore size changes in response to external stimuli, and an absorbent / heat-generating section including a medium that adsorbs and desorbs onto the porous material, A housing section for housing the heat-absorbing and heat-generating section, An external stimulus input unit that applies the external stimulus to the porous material, A heat exchange channel through which a heat transfer medium, which is heated or cooled by heat exchange with the aforementioned housing section, Equipped with, The external stimulus is two or more light stimuli with different wavelengths, and the porous material comprises a porous body and a photoisomerized layer containing a photoisomerized compound formed on the surface of the pores of the porous body. A heat exchange device in which, upon adsorption of the medium, a portion of the photoisomerized compound dissolves in the medium, and upon desorption of the medium, reprecipitation occurs; Item 2: The housing is movable within the heat exchange channel, The aforementioned housing unit moves inside the heat exchange channel while heat exchange is performed. The heat exchange channel comprises a cold air channel having a cold air generating section in which the heat transfer medium is cooled by the heat absorption and heat generation section absorbing heat, and a hot air channel having a hot air generating section in which the heat transfer medium is heated by the heat absorption and heat generation section generating heat. The heat exchange apparatus according to claim 1, wherein at least one external stimulus input unit is provided in at least one of the hot air generating unit and the cold air generating unit; Item 3: The stimulus-responsive unit comprising the housing section and the external stimulus unit is movable within the heat exchange channel, A heat exchange apparatus according to claim 1 or 2, wherein heat exchange is performed while the stimulus-responsive unit moves inside the heat exchange channel; Item 4: The heat exchanger according to any one of items 1 to 3, further comprising a medium pressure adjusting means connected to the housing and for adjusting the pressure of the medium in the housing by controlling the amount of the medium in the housing; Item 5: The pore size of the porous material reversibly changes from B to A by external stimulus 1, and reversibly changes from A to B by external stimulus 2, and A > B. A heat exchange apparatus according to any one of claims 1 to 4, wherein the medium is adsorbed onto the porous material when the pore diameter is A, the pore diameter is changed from A to B by the external stimulus 2, and the medium is desorbed by further changing the pore diameter from B to A by the external stimulus 1; Item 6: The pore size of the porous material reversibly changes from B to A by external stimulus 1, and reversibly changes from A to B by external stimulus 2, and A > B. A heat exchange apparatus according to any one of claims 1 to 4, wherein the medium is adsorbed onto the porous material when the pore diameter is B, and the medium is desorbed by changing the pore diameter from B to A by the external stimulus 1; Item 7: The pore size of the porous material reversibly changes from B to A by external stimulus 1, and reversibly changes from A to B by external stimulus 2, and A > B. A heat exchange apparatus according to any one of claims 1 to 4, wherein the medium is adsorbed onto the porous material while the pore diameter is B, the pore diameter is changed from B to A by the external stimulus 1, then the pore diameter is changed from A to B by the external stimulus 2, and the medium is desorbed by further changing the pore diameter from B to A by the external stimulus 1; Item 8: The heat exchange apparatus according to any one of items 1 to 7, wherein the light stimuli are two types of light stimuli with wavelengths λ1 and λ2, respectively, and when the reflectance of the inner wall of the housing for light of wavelength λ1 is Rλ1 and the reflectance for light of wavelength λ2 is Rλ2, the housing is a container in which the reflectance of the inner wall on the extension of the incident light of wavelength λ1 satisfies Rλ1 ≥ Rλ2, and the reflectance of the inner wall on the extension of the incident light of wavelength λ2 satisfies Rλ2 ≥ Rλ1; Item 9: A vehicle air conditioning system using a heat exchanger as described in any of items 1 to 8. [Examples]

[0063] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples.

[0064] [Example 1] As a porous material, we prepared MCM-41 (MERCK Sigma-Aldrich, 643645), a mesoporous silica. TEM observation revealed that the mesoporous silica had a hexagonal structure and one-dimensional pores with a pore diameter of 3.78 nm. The pore volume of the mesoporous silica was 0.621 cm³. 3 The concentration was / g. 4-(phenylazo)benzoic acid, a photoisomerized compound, was introduced into the pores of this mesoporous silica using a solution introduction method. Specifically, first, an ethanol solution of 4-(phenylazo)benzoic acid was prepared. The solution concentration was φ, which will be described later. AZO The ratio was adjusted to 0.48. Next, the dehydrated mesoporous silica was weighed and its mass m MCM The following was determined: An ethanol solution of 4-(phenylazo)benzoic acid prepared above was added to a vial containing dehydrated mesoporous silica, and the vial was sealed and left to stand in a dark room for 24 hours. The vial was removed from the dark room and dried in a fume hood. The mass of this sample was measured, and from this mass, m MCM Subtracting this, the mass m of the photoisomerized compound filling the pores of the mesoporous silica is Azo This was determined. In this way, a porous material having a photoisomerized layer containing 4-(phenylazo)benzoic acid on the surface of the pores of mesoporous silica was obtained.

[0065] Note, φ AZO The ratio of the volume of the photoisomerized compound present in the pores to the total pore volume of the porous material was calculated according to the following formula:

[0066]

number

[0067] In the above formula, m MCM m is the mass of mesoporous silica, Azo V is the mass of the photoisomerized compound packed into the pores of mesoporous silica. MCM ρ is the pore volume of mesoporous silica, AZO V is the bulk density of the photoisomerized compound. Note that V is the pore volume of mesoporous silica. MCM This was calculated from the results of nitrogen adsorption measurements.

[0068] The water vapor adsorption / desorption isotherms were measured for the obtained porous material by varying the presence or absence of ultraviolet light irradiation. The light source used was a High Power xenon lamp light source MAX-301 manufactured by Asahi Spectroscopic Co., Ltd., and ultraviolet light was irradiated onto the porous material using the xenon lamp with a UV mirror module, bandpass filter, and light guide rod. The water vapor adsorption / desorption isotherms were measured using a volumetric adsorption isotherm measuring device. Figures 9A and 9B show the water vapor adsorption / desorption isotherms when ultraviolet light irradiation was not performed for both the adsorption and desorption processes (OFF-OFF), and when ultraviolet light irradiation was performed only for the desorption process after saturated adsorption (OFF-ON). In Figures 9A and 9B, open plots represent the adsorption process, and filled plots represent the desorption process.

[0069] As shown in Figures 9A and 9B, a two-stage rise in the adsorption isotherm was observed in both cases: when no ultraviolet light irradiation was performed during either the adsorption or desorption process (OFF-OFF) and when ultraviolet light irradiation was performed only during the desorption process after saturated adsorption (OFF-ON). The first stage rise is thought to correspond to the adsorption of water vapor onto the surface of the mesoporous silica pores, forming a meniscus, while the second stage rise is thought to be due to the dissolution of some of the 4-(phenylazo)benzoic acid into the adsorbed water. As shown in Figure 9A, after the second stage rise, the adsorption isotherm behaves similarly to that of mesoporous silica until it reaches a saturated adsorption state. In this case, as shown in Figure 9A, a second stage rise is observed in the adsorption isotherm when ultraviolet light irradiation was performed only during the desorption process after saturated adsorption (OFF-ON), and the amount of water vapor adsorbed (120 mgg) corresponds to the size (height) of this rise. -1 (Silica)) Total adsorption amount (740 mg -1 If the amount of water vapor adsorbed relative to silica was less than 60%, it was determined that a portion of the photoisomerized compound dissolved in the water medium during adsorption. In this example, as shown in Figure 9A, this value was less than 60%. On the other hand, if a second rise was not observed in the adsorption isotherm, it was determined that the photoisomerized compound did not dissolve in the water medium. Furthermore, if a second rise was observed in the adsorption isotherm, and the amount of water vapor adsorbed corresponding to its size (height) was 60% or more of the total adsorbed amount, it was determined that all of the photoisomerized compound dissolved completely in the water medium during adsorption.

[0070] During adsorption, a portion of the photoisomerized compound dissolves in the water medium, which can improve the utilization rate of the pore volume and potentially enhance the exothermic performance. Table 1 below shows the estimated exothermic output under two scenarios: one where 4-(phenylazo)benzoic acid adsorbed on mesoporous silica is not completely dissolved (immobilized) and another where it is completely dissolved (completely dissolved). In Table 1, the pore volume was calculated based on the results of nitrogen adsorption measurements. For the scenario where complete dissolution was assumed, the pore volume of the mesoporous silica before the adsorption of 4-(phenylazo)benzoic acid was used. The amount of water adsorbed was calculated by multiplying the pore volume by the density of water. The amount of exothermic output was calculated by multiplying the latent heat of water by the amount of water adsorbed. The results in the table below show that the exothermic output can be improved when a portion of the photoisomerized compound dissolves in water during adsorption.

[0071] [Table 1]

[0072] Furthermore, as shown in Figures 9A and 9B, in both cases—when ultraviolet light irradiation was not performed during either the adsorption or desorption process (OFF-OFF) and when ultraviolet light irradiation was performed only during the desorption process after saturated adsorption (OFF-ON)—a two-stage decline in the desorption isotherm was observed. The first stage of decline (water vapor adsorption: 460-580 mgg) -1 The (silica) is thought to be due to the reprecipitation of 4-(phenylazo)benzoic acid. Also, the second stage decline (water vapor adsorption amount: 180~450 mg) -1 The (silica) is thought to be due to the breakdown of the meniscus. When ultraviolet light irradiation was performed only during the desorption process after saturated adsorption (OFF-ON), compared to when ultraviolet light irradiation was not performed during either the adsorption or desorption process (OFF-OFF), a larger desorption occurred due to the change in pore size caused by ultraviolet light irradiation, and a larger falloff was observed. Specifically, when comparing the amount of desorption under the same relative pressure conditions, the amount of desorption is larger in the OFF-ON case (the amount of adsorption is smaller). This indicates that the pore size is larger and desorption is promoted, and it can be said that the difference in refrigerant is desorbed by light irradiation and generates cold or heat.

[0073] [Example 2] A porous material was prepared in the same manner as in Example 1, except that 3,3'-dimethylazobenzene was used instead of 4-(phenylazo)benzoic acid as the photoisomerized compound, and the water vapor adsorption / desorption isotherm was measured. The results are shown in Figure 9B. As shown in Figure 9B, a two-stage rise was observed in the adsorption isotherm even when 3,3'-dimethylazobenzene was used (first stage rise: relative pressure around 0.55, water vapor adsorption amount: 100-300 mgg). -1 (Silica) Second stage rise: relative pressure around 0.9, water vapor adsorption: 400-700 mg -1 (Silica) When UV light irradiation is applied only during the desorption process after saturated adsorption (OFF-ON), the amount of water vapor adsorbed corresponds to the magnitude (height) of the rise in the second stage of the adsorption isotherm, which is equal to the total adsorption amount (700 mgg). -1 The amount of photoisomerized compound was less than 60% of the silica, confirming that some of the photoisomerized compound dissolved in the medium during adsorption. The magnitude of the rise in the second stage of the adsorption isotherm was greater than that of 4-(phenylazo)benzoic acid in Example 1. This is thought to be because 3,3'-dimethylazobenzene, which has a methyl group, has weaker intermolecular forces with the wall of mesoporous silica compared to 4-(phenylazo)benzoic acid, which has a carboxyl group, and is therefore more easily soluble in the solvent. In addition, the desorption isotherm also showed a two-stage decline (first stage decline: relative pressure around 0.75, water vapor adsorption amount: 370-600 mgg). -1 (Silica), second stage decline: relative pressure around 0.4, water vapor adsorption amount: 150-250 mg -1 Silica was observed, confirming that photoisomerized compounds reprecipitation occurred during desorption. Furthermore, when UV light irradiation was performed only during the desorption process after saturated adsorption (OFF-ON), the amount of adsorption was lower at relative pressures of around 0.75-0.8 compared to when UV light irradiation was not performed during either the adsorption or desorption process (OFF-OFF). This indicates that UV light irradiation increases the pore size, promoting desorption, and that the difference in refrigerant is desorbed by light irradiation, generating cooling.

[0074] [Comparative Example 1] A porous material was prepared in the same manner as in Example 1, except that azobenzene was used instead of 4-(phenylazo)benzoic acid as the photoisomerized compound, and the water vapor adsorption / desorption isotherm was measured. The results are shown in Figure 9B. As shown in Figure 9B, a two-stage rise was observed in the adsorption isotherm even when azobenzene was used (second stage rise: relative pressure around 0.9, water vapor adsorption amount: 400-1000 mgg). -1 (Silica). However, as shown in Figure 9B, when ultraviolet light irradiation was performed only during the desorption process after saturated adsorption (OFF-ON), the amount of water vapor adsorbed, which corresponds to the height of the second rise in the adsorption isotherm, was 60% or more of the total adsorbed amount, indicating that all of the photoisomerized compound was dissolved in the medium (completely dissolved) during adsorption. In this case, there was no significant difference in the desorption isotherm between the case where ultraviolet light irradiation was not performed during both the adsorption and desorption processes (OFF-OFF) and the case where ultraviolet light irradiation was performed only during the desorption process after saturated adsorption (OFF-ON), and rapid desorption of the medium due to changes in pore size caused by light stimulation was not observed.

[0075] Thus, it was found that porous materials in which the pore size changes due to light stimulation, allowing a medium to be adsorbed and desorbed, can generate a sufficient amount of heat due to the heat of adsorption of the medium. Furthermore, it was found that by using a porous material having a photoisomerized layer containing a photoisomerized compound formed on the surface of the pores of the porous body, and controlling the process so that a portion of the photoisomerized compound dissolves in the medium during adsorption and reprecipitations during desorption, the amount of medium adsorbed can be improved. Therefore, such porous materials can be suitably used in the heat absorption and heat generation sections of heat exchangers. [Explanation of Symbols]

[0076] 1 porous material, 2. Porous material, 3 medium, 4 pores, 5. Meniscus of the adsorbed medium, 6 photoisomerization layer, 7 Inner wall, 11. Heat-absorbing and heat-generating section, 20. Media pressure adjustment means, 21 media tanks, 22 Medium flow path, 100 storage units, 150 Air passage (heat exchange passage), 152 Air (heat transfer medium), 200, 200A, 200B heat exchange equipment, 201 Cool air generating unit, 202 Hot air generating unit, 600, 601, 602, 603, 604 External stimulus input units, 700 stimulus-responsive units 1501 Cold air channel, 1502 Hot air flow path, A, B, D Pore diameter, Lc azobenzene compound molecular length, Lt Molecular length of the trans isomer of azobenzene compound, P pump, P11 inlet, P21 Outlet.

Claims

1. A porous material whose pore size changes in response to external stimuli, and an absorbent / heat-generating section containing a medium that adsorbs and desorbs onto the porous material, A housing section for housing the heat-absorbing and heat-generating section, An external stimulus input unit that applies the external stimulus to the porous material, A heat exchange channel through which a heat transfer medium, which is heated or cooled by heat exchange with the aforementioned housing section, Equipped with, The external stimulus is two or more types of light stimuli with different wavelengths, and the porous material comprises a porous body and a photoisomerized layer containing a photoisomerized compound formed on the surface of the pores of the porous body. A heat exchange device in which a portion of the photoisomerized compound dissolves in the medium during adsorption and reprecipitation occurs during desorption of the medium.

2. The housing portion is movable inside the heat exchange channel, The aforementioned housing unit moves inside the heat exchange channel while heat exchange is performed. The heat exchange channel comprises a cold air channel having a cold air generating section in which the heat transfer medium is cooled by the heat absorption and heat generation section absorbing heat, and a hot air channel having a hot air generating section in which the heat transfer medium is heated by the heat absorption and heat generation section generating heat. The heat exchange apparatus according to claim 1, wherein at least one of the external stimulus input units is disposed in at least one of the hot air generating unit and the cold air generating unit.

3. The stimulus-responsive unit, comprising the housing section and the external stimulus unit, is movable within the heat exchange channel. The heat exchange apparatus according to claim 1, wherein heat exchange is performed while the stimulus-responsive unit moves inside the heat exchange channel.

4. The heat exchanger according to claim 1, further comprising a medium pressure adjusting means connected to the housing section for adjusting the pressure of the medium in the housing section by controlling the amount of the medium in the housing section.

5. The pore size of the porous material reversibly changes from B to A in response to external stimulus 1, and reversibly changes from A to B in response to external stimulus 2, and A > B. The heat exchange apparatus according to claim 1, wherein the medium is adsorbed onto the porous material when the pore diameter is A, the pore diameter is changed from A to B by the external stimulus 2, and the medium is desorbed by further changing the pore diameter from B to A by the external stimulus 1.

6. The pore size of the porous material reversibly changes from B to A in response to external stimulus 1, and reversibly changes from A to B in response to external stimulus 2, and A > B. The heat exchange device according to claim 1, wherein the medium is adsorbed onto the porous material when the pore diameter is B, and the medium is desorbed by changing the pore diameter from B to A by the external stimulus 1.

7. The pore size of the porous material reversibly changes from B to A in response to external stimulus 1, and reversibly changes from A to B in response to external stimulus 2, and A > B. The heat exchange device according to claim 1, wherein the medium is adsorbed onto the porous material while the pore diameter is B, the pore diameter is changed from B to A by the external stimulus 1, then the pore diameter is changed from A to B by the external stimulus 2, and the medium is desorbed by further changing the pore diameter from B to A by the external stimulus 1.

8. wherein said light stimuli are two types of light stimuli with wavelengths of λ respectively １ and λ ２ , and when the reflectance of the inner wall of said accommodating portion for light of wavelength λ １ is defined as Rλ １ , and the reflectance for light of wavelength λ ２ is defined as Rλ ２ , said accommodating portion is a container that satisfies that the reflectance of the inner wall located on the extension line of the incident light of wavelength λ １ is Rλ １ ≧Rλ ２ , and the reflectance of the inner wall located on the extension line of the incident light of wavelength λ ２ is Rλ ２ ≧Rλ １ , The heat exchange device according to claim 1.

9. A vehicle air conditioning system using the heat exchanger described in claim 1.

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