JP2006220326A - Heat exchanging system - Google Patents

Heat exchanging system Download PDF

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JP2006220326A
JP2006220326A JP2005032213A JP2005032213A JP2006220326A JP 2006220326 A JP2006220326 A JP 2006220326A JP 2005032213 A JP2005032213 A JP 2005032213A JP 2005032213 A JP2005032213 A JP 2005032213A JP 2006220326 A JP2006220326 A JP 2006220326A
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fine particles
porous layer
exchange system
heat exchange
heat
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Yasuhiro Yoshida
育弘 吉田
Toshiyuki Toyoshima
利之 豊島
Teruhiko Kumada
輝彦 熊田
Tetsuro Ogushi
哲朗 大串
Koji Kichise
幸司 吉瀬
Shinichi Wakamoto
慎一 若本
Taijo Murakami
泰城 村上
Hajime Yoshiyasu
一 吉安
Hide Yamashita
秀 山下
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanging system remarkably improved in its heat transferring performance to be used in an air conditioner and a water heater which are miniaturized and increased in capacity, or a semiconductor device and a thermal device. <P>SOLUTION: In this heat exchanging system comprising a solid and a porous layer formed on a surface of the solid and having hole portions of a diameter of 100 nm or less, the porous layer is formed by using a plurality of fine particles of various hydrophilic properties, or by using a plurality of fine particles of various heat conductivities. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

熱交換器、ヒートシンク等に用いる熱交換システムに関するものである。   The present invention relates to a heat exchange system used for a heat exchanger, a heat sink and the like.

熱交換器やヒートシンクでは、接する気体の流れや機器の形状を工夫して、熱伝達性能の向上を図っている。しかし、機器の形状や大きさなどに制約があり、このようにして得られる熱交換器やヒートシンクでは、熱伝達性能の向上には限界があった。
しかし、最近、対流熱伝達に関して、低コストで画期的に高い効率を示す熱交換システムが提案されている。それは、流体と接する固体表面に、多数のナノサイズの気孔を有する多孔層を設けた熱交換システムである。この熱交換システムの多孔層は、金属等の固体表面に、直径１００ｎｍ以下の酸化銅、アルミナ、炭素などの粒子、あるいは直径が１００ｎｍ以下のカーボンナノチューブを塗布処理して得られる。（例えば、特許文献１参照）。 In heat exchangers and heat sinks, the heat flow performance is improved by devising the flow of gas in contact and the shape of the equipment. However, there are restrictions on the shape and size of the equipment, and the heat exchanger and heat sink obtained in this way have limited improvements in heat transfer performance.
Recently, however, a heat exchange system has been proposed that exhibits an epoch-making high efficiency at a low cost for convective heat transfer. It is a heat exchange system in which a solid surface in contact with a fluid is provided with a porous layer having a large number of nano-sized pores. The porous layer of this heat exchange system is obtained by coating a solid surface of metal or the like with particles of copper oxide, alumina, carbon or the like having a diameter of 100 nm or less, or carbon nanotubes having a diameter of 100 nm or less. (For example, refer to Patent Document 1).

ＷＯ２００４／０３３９８０号パンフレット（第１頁〜第２頁）WO2004 / 033980 pamphlet (first page to second page)

上記、多数のナノサイズの気孔を有する多孔層を設けた熱交換システムは、この多孔層を設けない金属などの固体表面が流体と接する熱交換システムに比べ、熱伝達性能が向上している。しかし、熱交換器が用いられる空調機や温水器、あるいはヒートシンクが用いられる半導体装置や熱機器などの、小型、大容量化に伴い、上記熱交換システムでも、熱伝達性能が不十分との問題があった。   The above heat exchange system provided with a porous layer having a large number of nano-sized pores has improved heat transfer performance compared to a heat exchange system in which a solid surface such as a metal not provided with the porous layer is in contact with a fluid. However, as air conditioners and water heaters using heat exchangers, semiconductor devices and heat appliances using heat sinks, etc. are becoming smaller and larger in capacity, the above heat exchange system also has a problem that heat transfer performance is insufficient. was there.

この発明は、上述のような課題を解決するためになされたもので、その目的は、小型・大容量の、空調機や温水器に用いる熱交換器、あるいは、半導体機器や熱機器に用いるヒートシンク、の熱伝達性能を大幅に向上できる熱交換システムを得ることである。   The present invention has been made to solve the above-described problems, and its purpose is to provide a small-sized and large-capacity heat exchanger for use in air conditioners and water heaters, or a heat sink for use in semiconductor equipment and thermal equipment. It is to obtain a heat exchange system that can greatly improve the heat transfer performance.

本発明の第１の熱交換システムは、固体と、固体表面に設けられた直径が１００ｎｍ以下の孔部を有する多孔層とを備えた熱交換システムであって、上記多孔層が親水性の異なる複数の微粒子で形成されたものである。   A first heat exchange system according to the present invention is a heat exchange system including a solid and a porous layer having a hole having a diameter of 100 nm or less provided on the surface of the solid, wherein the porous layer has different hydrophilicity. It is formed of a plurality of fine particles.

本発明の第２の熱交換システムは、固体と、固体表面に設けられた直径が１００ｎｍ以下の孔部を有する多孔層とを備えた熱交換システムであって、上記多孔層が熱伝導率の異なる複数の微粒子で形成されたものである。   The second heat exchange system of the present invention is a heat exchange system comprising a solid and a porous layer having a hole having a diameter of 100 nm or less provided on the surface of the solid, wherein the porous layer has a thermal conductivity. It is formed of a plurality of different fine particles.

本発明の第１の熱交換システムは、固体と、固体表面に設けられた直径が１００ｎｍ以下の孔部を有する多孔層とを備えた熱交換システムであって、上記多孔層が親水性の異なる複数の微粒子で形成されたものであり、気相への熱伝達性能を大幅に向上できる。   A first heat exchange system according to the present invention is a heat exchange system including a solid and a porous layer having a hole having a diameter of 100 nm or less provided on the surface of the solid, wherein the porous layer has different hydrophilicity. It is formed of a plurality of fine particles, and can greatly improve the heat transfer performance to the gas phase.

本発明の第２の熱交換システムは、固体と、固体表面に設けられた直径が１００ｎｍ以下の孔部を有する多孔層とを備えた熱交換システムであって、上記多孔層が熱伝導率の異なる複数の微粒子で形成されたものであり、気相への熱伝達性能を大幅に向上できる。   The second heat exchange system of the present invention is a heat exchange system comprising a solid and a porous layer having a hole having a diameter of 100 nm or less provided on the surface of the solid, wherein the porous layer has a thermal conductivity. It is formed of a plurality of different fine particles, and can greatly improve the heat transfer performance to the gas phase.

実施の形態１．
固体から気相流体への熱伝達においては、境界面での熱伝達効率が支配的である。この境界面で熱伝達効率の向上には、境界面での水分子の挙動が重要な要因となっており、詳細なメカニズムは明確ではないが、多数のナノサイズの孔を有する多孔層を設けた熱交換システムでは、多孔層の孔部から脱着する水分子により、固体表面から熱エネルギーを効率よく持ち出せるようにすることが、熱交換システムの熱伝達性能を大幅に向上できることである。 Embodiment 1 FIG.
In heat transfer from a solid to a gas phase fluid, the heat transfer efficiency at the interface is dominant. In order to improve the heat transfer efficiency at this interface, the behavior of water molecules at the interface is an important factor, and although the detailed mechanism is not clear, a porous layer with many nano-sized pores is provided. Furthermore, in the heat exchange system, heat energy can be efficiently taken out from the solid surface by water molecules desorbed from the pores of the porous layer, which can greatly improve the heat transfer performance of the heat exchange system.

図1は、本実施の形態の熱交換システムを示す模式図である。
図１に示すように、本実施の形態の熱交換システム１は、基材２の固体表面に、多孔層３が設けられており、多孔層３には、ナノサイズの孔部４が形成されている。
例えば、上記孔部４表面の親水性が大きすぎると、孔部４の水分吸着能が大きく、孔部からの脱着が不十分となり、孔部からの脱着分子による固体表面からの熱エネルギーの持ち出しが小さい。また、上記孔部４表面の親水性が小さすぎると、つまり、疎水性が大きすぎると、孔部４へ入る水分が少なくなり、脱着水分量が少なく、やはり、脱着分子による固体表面からの熱エネルギーの持ち出しが小さくなる。
それと、例えば、孔部４表面の温度が高すぎると、孔部４に吸着する水分量が少なくなり、結果として、脱着水分量が少なく、固体表面からの熱エネルギーの持ち出しが小さい。また、孔部４表面の温度が低くすぎると、吸着する水分量は多いが、脱着するエネルギーが十分ではなく、やはり、脱着水分量が少なく、固体表面からの熱エネルギーの持ち出しが小さくなる。
すなわち、多孔層３の孔部４からの水分子の吸着と脱着とのバランスが、熱伝達効率に影響しており、適正な水分子の吸着能と脱着能を有する孔部４が形成された多孔層３を設けた熱交換システム１が、気相への熱伝達性能を大幅に向上できることを見出した。 FIG. 1 is a schematic diagram showing a heat exchange system of the present embodiment.
As shown in FIG. 1, in the heat exchange system 1 according to the present embodiment, a porous layer 3 is provided on a solid surface of a substrate 2, and nano-sized pores 4 are formed in the porous layer 3. ing.
For example, when the hydrophilicity of the surface of the hole 4 is too large, the water adsorption capacity of the hole 4 is large and the desorption from the hole becomes insufficient, and the heat energy is taken out from the solid surface by the desorbed molecules from the hole. Is small. On the other hand, if the hydrophilicity of the surface of the hole 4 is too small, that is, if the hydrophobicity is too large, the amount of water entering the hole 4 is small and the amount of desorbed water is small. Less energy is taken out.
In addition, for example, if the temperature of the surface of the hole 4 is too high, the amount of moisture adsorbed on the hole 4 is reduced, and as a result, the amount of desorbed moisture is small and the heat energy is not taken out from the solid surface. If the temperature of the surface of the hole 4 is too low, the amount of moisture adsorbed is large, but the energy for desorption is not sufficient, and the amount of desorption moisture is also small, so that heat energy is not taken out from the solid surface.
That is, the balance between the adsorption and desorption of water molecules from the pores 4 of the porous layer 3 affects the heat transfer efficiency, and the pores 4 having appropriate adsorption and desorption capabilities of water molecules are formed. It has been found that the heat exchange system 1 provided with the porous layer 3 can greatly improve the heat transfer performance to the gas phase.

本実施の形態における、多孔層３の孔部４からの水分子の吸着と脱着とのバランスがとれた第１の熱交換システムは、表面の親水性が異なる複数のナノサイズ微粒子を混合して得られたナノサイズ微粒子で多孔層を形成したものである。
図２は第１の熱交換システムの多孔層の孔部のモデル図である。図２に示すように、親水性の微粒子１０と疎水性の微粒子１１とで、孔部表面が形成されており、水分子の吸着と脱着とのバランスのとれた多孔層３となっている。
この場合、親水性の小さい疎水性の微粒子としては、微粒子を水に入れた時に、水中で混合されない程度に疎水性を有するものが好ましい。親水性は表面に対する水分子の吸着しやすさで比較できる。具体的には、室温から１２０℃までの昇温時の脱着水分量を求める試験において、脱着水分量が少ないほど疎水性が大きいとなる。親水性の小さい疎水性の微粒子としては、上記試験において、親水性の大きい微粒子の脱着水分量と比較して、脱着水分量が５０％以下ものが好ましい。 In the present embodiment, the first heat exchange system in which the adsorption and desorption of water molecules from the pores 4 of the porous layer 3 are balanced is obtained by mixing a plurality of nano-sized fine particles having different surface hydrophilicity. A porous layer is formed with the obtained nano-sized fine particles.
FIG. 2 is a model diagram of the pores of the porous layer of the first heat exchange system. As shown in FIG. 2, the pore surface is formed by the hydrophilic fine particles 10 and the hydrophobic fine particles 11, and the porous layer 3 has a good balance between adsorption and desorption of water molecules.
In this case, the hydrophobic fine particles having a small hydrophilicity are preferably those having a hydrophobic property to the extent that they are not mixed in water when the fine particles are placed in water. The hydrophilicity can be compared by the ease of water molecule adsorption to the surface. Specifically, in a test for determining the amount of desorption moisture at a temperature rise from room temperature to 120 ° C., the smaller the amount of desorption moisture, the greater the hydrophobicity. As the hydrophobic fine particles having small hydrophilicity, those having a desorption moisture amount of 50% or less are preferable in the above test as compared with the desorption moisture amount of the fine hydrophilic particles.

多孔層３の孔部４からの水分子の吸着と脱着とのバランスがとれた第２の熱交換システムは、熱伝導率が異なる複数のナノサイズ微粒子を混合して得られたナノサイズ微粒子で多孔層を形成したものである。
図３は第２の熱交換システムの多孔層の孔部のモデル図である。図３に示すように、熱伝導率が大きい微粒子１２と熱伝導率が小さい微粒子１３とで、孔部表面が形成されており、水分子の吸着と脱着とのバランスのとれた多孔層３となっている。
この場合、熱伝導率が小さい微粒子の熱伝導率に対する熱伝導率が大きい微粒子の熱伝導率が、１．５倍以上であることが好ましく、５倍以上であることがさらに好ましい。 The second heat exchange system that balances the adsorption and desorption of water molecules from the pores 4 of the porous layer 3 is a nano-sized fine particle obtained by mixing a plurality of nano-sized fine particles having different thermal conductivities. A porous layer is formed.
FIG. 3 is a model diagram of the pores of the porous layer of the second heat exchange system. As shown in FIG. 3, the pore layer surface is formed by the fine particles 12 having a high thermal conductivity and the fine particles 13 having a low thermal conductivity, and the porous layer 3 in which the adsorption and desorption of water molecules are balanced. It has become.
In this case, the thermal conductivity of the fine particles having a large thermal conductivity relative to the thermal conductivity of the fine particles having a small thermal conductivity is preferably 1.5 times or more, and more preferably 5 times or more.

本実施の形態で用いられる微粒子としては、金属、金属の酸化物、窒化物、ホウ化物、炭化物等、グラファイト等の炭素化合物、炭化水素等の各種有機物が挙げられる。そして、微粒子の平均粒径は１０ｎｍ〜２５０ｎｍが好ましい。
本実施の形態で用いられる多孔層を設ける固体、すなわち基材２には、アルミニウムや銅などの金属、アルミナなどの金属酸化物、カーボン、プラスチックが挙げられるが、熱伝導率が高いものが好ましい。
多孔層３の厚さは、２０ｎｍ〜１００μｍであることが好ましく、０．５μｍ〜５０μｍであることがさらに好ましい。２０ｎｍ未満では微粒子が基材表面を覆うことが困難で有効な多孔層を形成できない。１００μｍより大きいと、多孔層自身による断熱により熱伝達性能が低下する。 Examples of the fine particles used in the present embodiment include metals, metal oxides, nitrides, borides, carbides, carbon compounds such as graphite, and various organic substances such as hydrocarbons. The average particle size of the fine particles is preferably 10 nm to 250 nm.
Examples of the solid provided with the porous layer used in the present embodiment, that is, the base material 2, include metals such as aluminum and copper, metal oxides such as alumina, carbon, and plastic, but those having high thermal conductivity are preferable. .
The thickness of the porous layer 3 is preferably 20 nm to 100 μm, and more preferably 0.5 μm to 50 μm. If it is less than 20 nm, it is difficult for the fine particles to cover the surface of the substrate, and an effective porous layer cannot be formed. If it is larger than 100 μm, the heat transfer performance deteriorates due to the heat insulation by the porous layer itself.

本実施の形態の熱交換システムは、以下のようにして作製する。
まず、複数の微粒子を水等の液体に混合させた混合液を準備する。この混合液には、バインダー成分、各種分散剤、凝集剤、界面活性剤などを添加しても良い。
次に、この混合液を、基材２の表面に塗布し、乾燥して、多孔層３を形成して、熱交換システム１とする。上記混合液の塗布方法としては、スピンコート法、スプレー法、ブラシ法、ローラーコート法、浸漬法などが挙げられる。 The heat exchange system of the present embodiment is manufactured as follows.
First, a mixed liquid in which a plurality of fine particles are mixed with a liquid such as water is prepared. You may add a binder component, various dispersing agents, a flocculant, surfactant, etc. to this liquid mixture.
Next, this mixed solution is applied to the surface of the substrate 2 and dried to form the porous layer 3, thereby forming the heat exchange system 1. Examples of the method for applying the mixed liquid include spin coating, spraying, brushing, roller coating, and dipping.

親水性の小さい、すなわち、疎水性の大きい微粒子は、例えば、無機の微粒子を有機物を溶かした溶液で処理し、無機微粒子の表面に有機物のコーティングを設けることにより得ることができる。
また、親水性を変える方法としては、上記方法のほか、各種の酸、アルカリ、酸化剤、還元剤などの処理、光、プラズマ、電子線などで処理が、挙げられる。 The fine particles having low hydrophilicity, that is, high hydrophobicity can be obtained, for example, by treating inorganic fine particles with a solution in which an organic substance is dissolved and providing a coating of the organic substance on the surface of the inorganic fine particles.
In addition to the above method, the method for changing hydrophilicity includes treatment with various acids, alkalis, oxidizing agents, reducing agents, etc., treatment with light, plasma, electron beam, and the like.

実施例１．
平均粒径１０ｎｍのチタニア微粒子と平均粒径４０ｎｍのシリカ微粒子との混合割合を変えた（シリカ微粒子が０重量％〜１００重量％）混合微粒子を調製する。
次に、上記混合微粒子を２重量パーセント含み、上記混合微粒子に対して２０重量％のペルオキソチタン酸を含む、水の混合液を調整する。この混合液をアルミニウム板上にスピンコートして、厚さ約１μｍの多孔層を形成し、熱交換システムサンプルを作製する。多孔層の厚さ調整は、乾燥とスピンコートとを数回繰り返して行う。 Example 1.
Mixed fine particles are prepared by changing the mixing ratio of titania fine particles having an average particle size of 10 nm and silica fine particles having an average particle size of 40 nm (silica fine particles are 0 wt% to 100 wt%).
Next, a mixed solution of water containing 2% by weight of the mixed fine particles and 20% by weight of peroxotitanic acid with respect to the mixed fine particles is prepared. This mixed solution is spin-coated on an aluminum plate to form a porous layer having a thickness of about 1 μm, and a heat exchange system sample is produced. The thickness of the porous layer is adjusted by repeating drying and spin coating several times.

次に、上記、チタニア微粒子とシリカ微粒子との混合割合が異なる多孔層を備えた各熱交換システムサンプルのアルミニウム板を６０℃に保持し、上記各熱交換システムサンプルの多孔層を設けた面から、２０℃、相対湿度２０％、レイノルズ数２００００の空気気流への、熱伝達効率（ヌッセルト数）を求めて比較した。
図４に、シリカ微粒子含有率とヌッセルト数との関係を示した。ヌッセルト数は、チタニア微粒子含有率が１００重量％（１００ｗｔ％）、すなわち、シリカ微粒子含有率が０重量％（０ｗｔ％）のサンプルの値と各サンプルの値との比で示した。
図４から、特に、シリカ微粒子含有率が１０〜５０重量％（１０〜５０ｗｔ％）の場合、熱伝達効率が高くなった。すなわち、表面の性状が異なり親水性が異なる微粒子で孔部表面を形成した多孔層を有する熱交換システムが、単一の微粒子で孔部表面を形成した多孔層を有する熱交換システムより、熱伝達性能が優れていることを示している。 Next, the aluminum plate of each heat exchange system sample provided with a porous layer in which the mixing ratio of titania fine particles and silica fine particles is different is maintained at 60 ° C., and from the surface on which the porous layer of each heat exchange system sample is provided The heat transfer efficiency (Nussell number) to an air stream having a temperature of 20 ° C., a relative humidity of 20%, and a Reynolds number of 20000 was determined and compared.
FIG. 4 shows the relationship between the silica fine particle content and the Nusselt number. The Nusselt number is indicated by the ratio between the value of each sample having a titania fine particle content of 100 wt% (100 wt%), that is, the silica fine particle content of 0 wt% (0 wt%).
From FIG. 4, in particular, when the silica fine particle content was 10 to 50 wt% (10 to 50 wt%), the heat transfer efficiency was high. That is, a heat exchange system having a porous layer in which the pore surface is formed with fine particles having different surface properties and different hydrophilicity is more heat transfer than a heat exchange system having a porous layer in which the pore surface is formed with a single fine particle. It shows that the performance is excellent.

実施例２.
微粒子として、実施例１の平均粒径１０ｎｍのチタニア微粒子に替えて、疎水化処理した平均粒径４０ｎｍのシリカ微粒子を用いる。
シリカ微粒子の疎水化処理は、シリカ微粒子にヘキサメチルジシラザン中をバブリングした窒素を接触させて行う。疎水化処理したシリカ微粒子は、室温から１２０℃まで昇温時の脱水量が、疎水化処理をしていないシリカ微粒子の約４分の１であった。
多孔層の形成は、上記混合微粒子を２重量％含有するアルコールの処理液を、アルミニウム板上にスプレーコートする。得られる多孔層の厚さは約３μｍである。 Example 2.
As fine particles, silica fine particles having an average particle diameter of 40 nm subjected to hydrophobic treatment are used instead of the titania fine particles having an average particle diameter of 10 nm in Example 1.
The hydrophobization treatment of the silica fine particles is performed by bringing nitrogen fine particles bubbled into hexamethyldisilazane into contact with the silica fine particles. Hydrophobized silica fine particles had a dehydration amount of about one-fourth of that of silica fine particles not subjected to hydrophobic treatment when heated from room temperature to 120 ° C.
The porous layer is formed by spray-coating an alcohol treatment solution containing 2% by weight of the mixed fine particles on an aluminum plate. The resulting porous layer has a thickness of about 3 μm.

疎水化シリカ微粒子の含有率（重量％）を変えた熱交換システムサンプルを作製し、実施例１と同様にして、熱伝達効率（ヌッセルト数）を求めて比較した。
図５に、疎水化シリカ微粒子含有率とヌッセルト数との関係を示した。ヌッセルト数は、疎水化シリカ微粒子含有率が０重量％のサンプルの値と各サンプルの値との比で示した。
図５から、特に、疎水化シリカ微粒子含有率が５〜５０重量％（５〜５０ｗｔ％）の場合、熱伝達効率が高くなった。すなわち、表面の性状が異なり親水性が異なる粒子で孔部表面を形成した多孔層を有する熱交換システムが、単一の粒子で孔部表面を形成した多孔層を有する熱交換システムより、熱伝達性能が優れていることを示している。 Heat exchange system samples with different content (% by weight) of hydrophobized silica fine particles were prepared, and heat transfer efficiency (Nussell number) was determined and compared in the same manner as in Example 1.
FIG. 5 shows the relationship between the hydrophobized silica fine particle content and the Nusselt number. The Nusselt number was expressed as a ratio between the value of the sample having a hydrophobized silica fine particle content of 0% by weight and the value of each sample.
From FIG. 5, in particular, when the content of hydrophobized silica fine particles was 5 to 50 wt% (5 to 50 wt%), the heat transfer efficiency was high. That is, a heat exchange system having a porous layer in which the pore surface is formed of particles having different surface properties and different hydrophilicity is more heat transfer than a heat exchange system having a porous layer in which the pore surface is formed of a single particle. It shows that the performance is excellent.

実施例３.
微粒子として、実施例１の平均粒径１０ｎｍのチタニア微粒子に替えて、平均粒径２０ｎｍのパラジウム微粒子を用いる。
多孔層の形成は、上記混合微粒子を２重量％含有し、上記混合微粒子に対して２０重量％のエチルシリケートを添加した、水の処理液を、銅板上にスプレーコートする。得られる多孔層の厚さは約０．５μｍである。 Example 3.
As fine particles, palladium fine particles having an average particle diameter of 20 nm are used in place of the titania fine particles having an average particle diameter of 10 nm in Example 1.
The porous layer is formed by spray-coating a treatment solution of water containing 2% by weight of the mixed fine particles and adding 20% by weight of ethyl silicate with respect to the mixed fine particles onto a copper plate. The resulting porous layer has a thickness of about 0.5 μm.

パラジウム微粒子の含有率（重量％）を変えた熱交換システムサンプルを作製し、銅板を６０℃に保持し、上記各熱交換システムサンプルの多孔層を設けた面から、２０℃、相対湿度２０％、レイノルズ数２００００の空気気流への、熱伝達効率（ヌッセルト数）を求めて比較した。
図６に、パラジウム微粒子含有率とヌッセルト数との関係を示した。ヌッセルト数は、パラジウム微粒子含有率が０重量％のサンプルの値と各サンプルの値との比で示した。
図６から、特に、パラジウム微粒子含有率が１０〜６０重量％（０〜６０ｗｔ％）の場合、熱伝達効率が高くなった。すなわち、熱伝導率が異なる微粒子で孔部表面を形成した多孔層を有する熱交換システムが、単一の微粒子で孔部表面を形成した多孔層を有する熱交換システムより、熱伝達性能が優れていることを示している。 A heat exchange system sample in which the content (% by weight) of the palladium fine particles was changed was prepared, the copper plate was held at 60 ° C., and the surface provided with the porous layer of each of the heat exchange system samples was 20 ° C. and the relative humidity was 20%. The heat transfer efficiency (Nussell number) to an air stream having a Reynolds number of 20000 was obtained and compared.
FIG. 6 shows the relationship between the palladium fine particle content and the Nusselt number. The Nusselt number was indicated by the ratio between the value of the sample having a palladium fine particle content of 0% by weight and the value of each sample.
From FIG. 6, in particular, when the palladium fine particle content was 10 to 60 wt% (0 to 60 wt%), the heat transfer efficiency was high. In other words, a heat exchange system having a porous layer having a pore surface formed of fine particles having different thermal conductivities has better heat transfer performance than a heat exchange system having a porous layer having a pore surface formed of a single fine particle. It shows that.

実施の形態１の熱交換システムを示す模式図である。1 is a schematic diagram illustrating a heat exchange system according to Embodiment 1. FIG. 実施の形態１における第１の熱交換システムの多孔層孔部のモデル図である。3 is a model diagram of a porous layer hole of the first heat exchange system in Embodiment 1. FIG. 実施の形態１における第２の熱交換システムの多孔層孔部のモデル図である。3 is a model diagram of a porous layer hole of the second heat exchange system in Embodiment 1. FIG. チタニア微粒子とシリカ微粒子との混合割合が異なる多孔層を備えた熱交換システムサンプルのシリカ微粒子含有率とヌッセルト数との関係を示す図である。It is a figure which shows the relationship between the silica fine particle content rate and Nusselt number of the heat exchange system sample provided with the porous layer from which the mixing ratio of a titania fine particle and a silica fine particle differs. 疎水化シリカ微粒子とシリカ微粒子との混合割合が異なる多孔層を備えた熱交換システムサンプルの疎水化シリカ微粒子含有率とヌッセルト数との関係を示す図である。It is a figure which shows the relationship between the hydrophobized silica microparticle content rate and the Nusselt number of the heat exchange system sample provided with the porous layer from which the mixing ratio of hydrophobized silica microparticles and silica microparticles differs. パラジウム微粒子とシリカ微粒子との混合割合が異なる多孔層を備えた熱交換システムサンプルのパラジウム微粒子含有率とヌッセルト数との関係を示す図である。It is a figure which shows the relationship between the palladium microparticle content rate and the Nusselt number of the heat exchange system sample provided with the porous layer from which the mixing ratio of palladium microparticles | fine-particles and silica microparticles differs.

符号の説明Explanation of symbols

１ 熱交換システム、２ 基材、３ 多孔層、４ 孔部、１０ 親水性の微粒子、１１ 疎水性の微粒子、１２ 熱伝導率が大きい微粒子、１３ 微粒子１２より熱伝導率が小さい微粒子。
DESCRIPTION OF SYMBOLS 1 Heat exchange system, 2 Base material, 3 Porous layer, 4 Hole part, 10 Hydrophilic fine particle, 11 Hydrophobic fine particle, 12 Fine particle with large thermal conductivity, 13 Fine particle with smaller thermal conductivity than fine particle 12.

Claims (6)

固体と、固体表面に設けられた直径が１００ｎｍ以下の孔部を有する多孔層とを備えた熱交換システムであって、上記多孔層が親水性の異なる複数の微粒子で形成されたことを特徴とする熱交換システム。   A heat exchange system comprising a solid and a porous layer having pores with a diameter of 100 nm or less provided on the surface of the solid, wherein the porous layer is formed of a plurality of fine particles having different hydrophilicity. Heat exchange system. 多孔層の孔部の表面に、親水性の異なる複数の微粒子が露出していることを特徴とする請求項１記載の熱交換システム。   The heat exchange system according to claim 1, wherein a plurality of fine particles having different hydrophilicity are exposed on the surface of the pores of the porous layer. 親水性が小さい第１の微粒子の室温から１２０℃までの昇温時の脱着水分量が、第１の微粒子より親水性が大きい第２の微粒子の室温から１２０℃までの昇温時の脱着水分量の５０％以下であることを特徴とする請求項１記載の熱交換システム。   Desorption moisture at the time of temperature rise from room temperature to 120 ° C. of the first fine particles having low hydrophilicity is desorption moisture at the time of temperature rise from room temperature to 120 ° C. of the second fine particles having higher hydrophilicity than the first fine particles The heat exchange system according to claim 1, wherein the heat exchange system is 50% or less of the amount. 固体と、固体表面に設けられた直径が１００ｎｍ以下の孔部を有する多孔層とを備えた熱交換システムであって、上記多孔層が熱伝導率の異なる複数の微粒子で形成されたことを特徴とする熱交換システム。   A heat exchange system comprising a solid and a porous layer having pores with a diameter of 100 nm or less provided on the surface of the solid, wherein the porous layer is formed of a plurality of fine particles having different thermal conductivities And heat exchange system. 多孔層の孔部の表面に、熱伝導率の異なる複数の微粒子が露出していることを特徴とする請求項４記載の熱交換システム。   The heat exchange system according to claim 4, wherein a plurality of fine particles having different thermal conductivities are exposed on the surfaces of the pores of the porous layer. 熱伝導率の大きい第１の微粒子の熱伝導率が、第１の微粒子の熱伝導率より小さい第２の微粒子の熱伝導率の１．５倍以上であることを特徴とする請求項４記載の熱交換システム。


5. The thermal conductivity of the first fine particles having a high thermal conductivity is 1.5 times or more the thermal conductivity of the second fine particles, which is smaller than the thermal conductivity of the first fine particles. Heat exchange system.


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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010175131A (en) * 2009-01-29 2010-08-12 Mitsubishi Electric Corp Heat exchange device, refrigerating air conditioner and method of manufacturing heat exchanger
WO2019163978A1 (en) * 2018-02-26 2019-08-29 国立大学法人名古屋大学 Heat exchanger, refrigerating machine and sintered body

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010175131A (en) * 2009-01-29 2010-08-12 Mitsubishi Electric Corp Heat exchange device, refrigerating air conditioner and method of manufacturing heat exchanger
WO2019163978A1 (en) * 2018-02-26 2019-08-29 国立大学法人名古屋大学 Heat exchanger, refrigerating machine and sintered body
US11796228B2 (en) 2018-02-26 2023-10-24 National University Corporation Tokai National Higher Education And Research System Heat exchanger, refrigerating machine and sintered body

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