ＯＴＥＣ
Vol. 18 (2013)，31〜36

伝熱面に微細な凹凸を有するプレート式蒸発器のアンモニア流動沸騰熱伝達に関する研究ఏ⇕㠃࡟ᚤ⣽࡞พฝࢆ᭷ࡍࡿࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢ࢔ࣥࣔࢽ࢔ὶືἛ㦐⇕ఏ㐩࡟㛵ࡍࡿ◊✲㸨ᑠᒣ ᖾᖹ*1㸪༓௦⏣ ⣫ா*2㸪᭷㤿 ༤ྐ*1㸪ᒸᮏ ᫂ኵ*3㸪ụୖ ᗣஅ*1
Heat Transfer Characteristics of Ammonia Flow Boiling in a Plate-type Evaporator withMicro-grooved Heat Transfer Surface
Kohei KOYAMA*1 Hirotaka CHIYODA*2, Hirofumi ARIMA*1, Akio OKAMOTO*3, and Yasuyuki IKEGAMI*1*1
Institute of Ocean Energy, Saga University
1-48, Hirao, Kubara-aza, Yamashiro-cho, Imari, Saga, 849-4256

Heat transfer characteristics of a plate-type evaporator which uses a micro-grooved heat transfer plate areexperimentally investigated. Working fluid is ammonia and the heat transfer plate is made by titanium. The effects ofmass flux, heat flux, channel height, and saturation pressure on heat transfer coefficient are discussed. Heat transfer
coefficient is presented as a function of vapor quality of the working fluid. Moreover, the heat transfer coefficient iscompared with that of a plate-type evaporator using smooth heat transfer surface. The results show that the channelheight and surface roughness significantly affect heat transfer performance of the evaporator.
Key Words : OTEC, Flow boiling, Heat transfer coefficient, Heat transfer enhamcement, Ammonia

1. ⥴   ゝᆅ⌫⎔ቃၥ㢟ࡸ࢚ࢿࣝࢠ࣮ၥ㢟࡟ᑐᛂࡋ㸪ᣢ⥆ྍ⬟࡞♫఍ࢆᵓ⠏ࡍࡿࡓࡵ࡟㸪෌⏕ྍ⬟࢚ࢿࣝࢠ࣮ࡢ㛤Ⓨࡀᙉࡃồࡵࡽࢀ࡚࠸ࡿ㸬ᾏὒ ᗘᕪⓎ㟁㸦OTEC㸧ࡣ㸪ᾏὒ⾲㠃ࡢ ᾏỈ࡜῝ᾏࡢ෭ᾏỈࢆ⏝࠸࡚Ⓨ㟁ࢆ⾜࠺ᢏ⾡࡛࠶ࡾ㸪෌⏕ྍ⬟࢚ࢿࣝࢠ࣮ࡢࡦ࡜ࡘ࡛࠶ࡿ㸬ᾏὒ ᗘᕪⓎ㟁ࡢᐇ⏝໬࠾ࡼࡧ㧗ຠ⋡໬ࡢࡓࡵ࡟ࡣ㸪సືὶయࢆຍ⇕⵨Ⓨࡉࡏࡿ⵨Ⓨჾࡢ㧗ຠ⋡໬ࡀ㔜せ࡛࠶ࡿ㸬ᾏὒ ᗘᕪⓎ㟁࡛ࡣ≉࡟㸪⇕஺᥮ຠ⋡㸪༢఩య✚࠶ࡓࡾࡢఏ⇕㠃✚ࡢ኱ࡁࡉ࠾ࡼࡧ࣓ࣥࢸࢼࣥࢫᛶࡢほⅬ࠿ࡽ㸪ࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡀ⏝࠸ࡽࢀࡿ㸬ࡲࡓ㸪ᾏὒ ᗘᕪⓎ㟁ࡢⓎ㟁ࢧ࢖ࢡࣝ࡟࠾ࡅࡿసືὶయ࡜ࡋ࡚ࡣ㸪࢔ࣥࣔࢽ࢔ࡀ᝿ᐃࡉࢀ࡚࠸ࡿ㸬࢔ࣥࣔࢽ࢔ࢆసືὶయ࡜ࡋࡓࣉ࣮ࣞࢺᘧ⵨ⓎჾࡢἛ㦐⇕ఏ㐩≉ᛶ࡟ࡘ࠸࡚ࡣ㸪᷸㒊(1)ࡽ࡟ࡼࡾᐇᶵࡢ OTEC ⏝⵨Ⓨჾ࡟ࡘ࠸࡚⇕㏻㐣⋡࡟ࡼࡿᩚ⌮ࡀ⾜ࢃࢀ㸪ࡲࡓ᭷㤿ࡽ(2)ࡣᐇᶵࢆᶍᨃࡋࡓࣉ࣮ࣞࢺ࡛ᒁᡤἛ㦐⇕ఏ㐩࡟ࡘ࠸࡚ ᐃࢆ⾜ࡗ࡚࠸ࡿ㸬ࡲࡓ㸪ࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢఏ⇕ಁ㐍࡟㛵㐃ࡋ㸪᭷㤿ࡽ(3)࡜ᒸᮏࡽ(4)ࡣ㸪ᖹ⁥࡞ࢳࢱࣥ〇ࣉ࣮ࣞࢺ࡟῝ࡉ 30μm ࡢᚤ⣽พฝ㠃ࢆタࡅࡿࡇ࡜࡛㸪ᖹ⁥㠃࡟ᑐࡋ࡚࢔ࣥࣔࢽ࢔ࡢ⇕ఏ㐩ࡀ 10~20%ྥୖࡍࡿࡇ࡜ࢆ᫂ࡽ࠿࡟ࡋ࡚࠸ࡿ㸬ఏ⇕㠃࡟⾲㠃ฎ⌮ࢆ᪋ࡍࡇ࡜࡛ఏ⇕ಁ㐍ࢆᅗࡿ◊✲ࡣ㸪Alam et al. (5)࡞࡝ࡀ࠶ࡾ㸪࠸ࡎࢀࡶ⾲㠃⢒ࡉࢆቑຍࡉࡏࡿࡇ࡜࡛ఏ⇕ಁ㐍ࢆ㐩ᡂࡋ࡚࠸ࡿ㸬ࡋ࠿ࡋ࡞ࡀࡽ㸪ఏ⇕㠃࡟ᚤ⣽࡞⾲㠃ຍᕤࢆ⾜ࡗࡓ㝿ࡢࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢఏ⇕≉ᛶࡢゎ᫂ࡣࡲࡔ༑ศ࡛ࡣ࡞ࡃ㸪㧗ຠ⋡⵨Ⓨჾࢆ㛤Ⓨࡍࡿࡓࡵ࡟㸪᭦࡞ࡿ◊✲ࡀồࡵࡽࢀࡿ㸬ᮏሗ࡛ࡣ㸪ᩥ⊩(3-4)࡟⥆ࡃ◊✲࡜ࡋ࡚㸪ఏ⇕㠃ୖ࡟ᚤ⣽࡞พฝຍᕤࢆ᪋ࡋࡓࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢఏ⇕≉ᛶ࡟୚࠼
ࡿ㉁㔞ὶ᮰㸪ὶ㊰㧗ࡉ㸪⇕ὶ᮰࠾ࡼࡧ㣬࿴ᅽຊࡢᙳ㡪ࢆሗ࿌ࡍࡿ㸬ࡲࡓ㸪㙾㠃௙ୖࡆࢆࡋࡓఏ⇕㠃ࢆ⏝࠸࡚ᚓࡽࢀࡓᐇ㦂⤖ᯝ࡜ẚ㍑ࡋ㸪ఏ⇕㠃࡟ᚤ⣽࡞พฝࢆ௜୚ࡍࡿࡇ࡜࡟ࡼࡿఏ⇕ಁ㐍ຠᯝ࡟ࡘ࠸࡚ࡶሗ࿌ࡍࡿ㸬*ཎ✏ཷ௜ 2013 ᖺ 7 ᭶ 31 ᪥
బ㈡኱Ꮫᾏὒ࢚ࢿࣝࢠ࣮◊✲ࢭࣥࢱ࣮㸦ࠛ849-4256 బ㈡┴ఀ୓㔛ᕷᒣ௦⏫ஂཎᏐᖹᑿ 1-48㸧
*2
బ㈡኱Ꮫ኱Ꮫ㝔ᕤᏛ⣔◊✲⛉*3⚄ᡞ〇㗰ᡤࢳࢱࣥᮏ㒊ࢳࢱࣥၟရᢏ⾡ᐊE-mail: koyama@ioes.saga-u.ac.jp
*131

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小山幸平，千代田紘享，有馬博史，岡本明夫，池上康之

2. ᐇ   㦂2࣭1 ᐇ㦂⿦⨨ᐇ㦂⿦⨨ࡢᴫ␎ᅗࢆᅗ 1 ࡟♧ࡍ㸬ᐇ㦂⿦⨨ࡣ㸪సືὶయ⣔⤫㸪 Ỉ⣔⤫࠾ࡼࡧ෭Ỉ⣔⤫ࡢ 3 ࡘ࡟ศࡅࡽࢀࡿ㸬సືὶయ⣔⤫ࡣ㸪⵨Ⓨჾ㸦ࢸࢫࢺ㒊㸧㸪จ⦰ჾ㸪సືὶయࢱࣥࢡ㸪ࢧࣈࢡ࣮࣮ࣛ㸪ࣉࣞࣄ࣮ࢱ࣮࡛ᵓᡂࡉࢀ࡚࠸ࡿ㸬సືὶయ⣔⤫࡛ࡣ㸪ᾮ┦ࡢ࢔ࣥࣔࢽ࢔ࡀ࣏ࣥࣉ࡟ࡼࡗ࡚సືὶయࢱࣥࢡ࠿ࡽ⵨Ⓨჾ࡟㏦ࡽࢀ㸪ຍ⇕⵨Ⓨࡍࡿ㸬Ẽᾮ஧┦ὶ࡜࡞ࡗࡓ࢔ࣥࣔࢽ࢔ࡣจ⦰ჾ࡟㏦ࡽࢀ㸪෭Ỉ࡟ࡼࡗ࡚ᾮ┦࡟จ⦰ࡉࢀࡓᚋ㸪సືὶయࢱࣥࢡ࡟ᡠࡉࢀࡿ㸬Ỉ⣔⤫࡛ࡣ㸪ᢞࡆ㎸ࡳࣄ࣮ࢱ࣮࡟ࡼࡗ࡚ ỈࢱࣥࢡෆࡢỈ ࡀ௵ពࡢ ᗘ࡟ຍ⇕ࡉࢀ㸪࣏ࣥࣉ࡟ࡼࡗ࡚ࣉࣞࣄ࣮ࢱ࣮࡟౪⤥ࡉࢀࡿ㸬ࣉࣞࣄ࣮ࢱ࣮࡛ࡣ㸪సືὶయࡀ௵ពࡢ⵨Ⓨჾධཱྀ᮲௳࡟ㄪ⠇ࡉࢀࡿ㸬෭Ỉ⣔⤫࡛ࡣ㸪෭෾ᶵ࡟ࡼࡗ࡚௵ពࡢ ᗘࡢ෭Ỉࡀసࡽࢀࡿ㸬ࡑࡢ෭Ỉࡣ࣏ࣥࣉ࡟ࡼࡗ࡚จ⦰ჾ࡟౪⤥ࡉࢀ㸪⵨Ⓨჾ࡛ຍ⇕ࡉࢀࡓసືὶయࢆ෭༷ࡍࡿ㸬ࡲࡓ㸪⿵ຓ෭Ỉ⣔⤫࡜ࡋ࡚㸪ᑠᆺ෭෾ᶵ࠾ࡼࡧࢧࣈࢡ࣮࣮ࣛࢆ㸪సືὶయࢱࣥࢡࡢୗὶ࡟タ⨨ࡋ࡚࠸ࡿ㸬࡞࠾㸪ఏ⇕㠃ࡢຍ⇕࡟ࡣ㸪7 ᮏࡢ 150W ࣟࢵࢻࣄ࣮ࢱ࣮ࢆ⏝࠸ࡓ㸬

Fig. 1 Schematic diagram of an experimental setup.

2࣭2 ࢸࢫࢺ㒊ᮏ◊✲࡛⏝࠸ࡿࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢᴫ␎ᅗࢆᅗ 2 ࡟♧ࡍ㸬⵨Ⓨჾࡣ㸪ࢳࢱࣥ〇ྎᗙ㸪సືὶయຍ⇕⏝ࣟࢵࢻࣄ࣮ࢱ࣮ࢆᤄධࡋࡓࣄ࣮ࢱ࣮ࣈࣟࢵࢡ㸪᩿⇕ᮦ㸪ࡑࡋ࡚ࢫࢸࣥࣞࢫ〇ࡢࢫ࣮࣌ࢧ࣮࡜ࣇ࣮࣒࡛ࣞᵓᡂࡉࢀࡿ㸬ࡇࢀࡽࢆ㔜ࡡྜࢃࡏ㸪⥾ࡵ௜ࡅࡿࡇ࡜࡛ࣉ࣮ࣞࢺᘧ⵨Ⓨჾ࡜ࡋ࡚⏝࠸ࡽࢀࡿ㸬࡞࠾㸪ఏ⇕㠃ࡣᖜ 100 mm ࠾ࡼࡧ㛗ࡉ
250 mm ࡛㸪ࢳࢱࣥ〇ྎᗙࡢୖ࡟ཌࡉ 0.4 mm ࡢࢳࢱࣥ〇ⷧᯈࢆࢁ࠺௜ࡅࡋࡓᵓ㐀࡜࡞ࡗ࡚࠸ࡿ㸬 ᮏ◊✲࡛ࡣ㸪ࡇࡢఏ⇕㠃࡟ᚤ⣽࡞พฝຍᕤࢆ᪋ࡋࡓ㸬ఏ⇕㠃⾲㠃ࡢᴫ␎ᅗࢆᅗ 3 ࡟♧ࡍ㸬ఏ⇕㠃ୖ࡟࠾࠸࡚㸪ᅗ 3 ࡢࡼ࠺࡟㸪῝ࡉ 30 μm ࠾ࡼࡧ㛗ࡉ 200 μm ࡢᚤ⣽࡞⁁ࢆ 100μm 㛫㝸࡛࢚ࢵࢳࣥࢢ࡟ࡼࡾຍᕤࡋ㸪㐃⥆ⓗ࡞ᚤ⣽พฝ㠃ࢆస〇ࡋࡓ㸬࡞࠾㸪ࣉ࣮ࣞࢺᘧ⵨Ⓨჾෆ㒊࡟࠾࠸࡚㸪సືὶయࡣ㸪พฝ㠃࡜┤஺ࡍࡿ᪉ྥ࡟౪⤥ࡉࢀࡿ㸬
ᅗ 4 ࡟㸪ࣉ࣮ࣞࢺᘧ⵨Ⓨჾෆ㒊࡟࠾ࡅࡿ ᗘ ᐃ఩⨨ࢆ♧ࡍ㸬ఏ⇕ࣉ࣮ࣞࢺෆ㒊࡟࠾࠸࡚㸪ᅗ 4 ࡢࡼ࠺࡟ K ᆺ⇕㟁ᑐࢆ㧗ࡉ᪉ྥ࡟ 5 ⟠ᡤ㸪ཌࡉ᪉ྥ࡟ 2 ⟠ᡤࡢィ 10 ᮏタ⨨ࡋࡓ㸬࡞࠾㸪ࣉ࣮ࣞࢺཌࡉ᪉ྥࡢ⇕㟁ᑐࡢ㛫㝸ࡣ
40 mm ࡛࠶ࡾ㸪㧗ࡉ᪉ྥࡢ㛫㝸ࡣ 59 mm ࡛࠶ࡿ㸬


伝熱面に微細な凹凸を有するプレート式蒸発器のアンモニア流動沸騰熱伝達に関する研究

33

Fig. 3 Heat transfer surface.
Fig. 2 Configuration of plate-type evaporator.

2࣭3 ⇕ఏ㐩⋡ᮏ◊✲࡛ࡣ㸪ࣉ࣮ࣞࢺᘧ⵨Ⓨჾ࡟࠾ࡅࡿసືὶయࡢὶࢀ᪉ྥ࡟ἢࡗࡓᒁᡤ⇕ఏ㐩⋡ࢆồࡵࡓ㸬ᅗ 4 ࡢࡼ࠺࡟ 10ᮏタ⨨ࡋࡓ⇕㟁ᑐ࡟ࡘ࠸࡚㸪ࡑࢀࡒࢀ 2 ᮏࢆ୍⤌࡜ࡋ㸪ᘧ(1)࡟ࡼࡾᒁᡤ⇕ὶ᮰ࢆồࡵࡓ㸬
q k T1  T2 l1(1)ࡇࡇ࡛ k ࡣࣉ࣮ࣞࢺࡢ⇕ఏᑟ⋡࡛࠶ࡾ㸪T1 ࡜ T2 ࡣᅗ 4 ࡟♧ࡍࣉ࣮ࣞࢺෆࡢ ᗘ㸪l1 ࡣ T1 ࡜ T2 ࡢ㊥㞳࡛࠶ࡿ㸬ࡉࡽ࡟㸪ᒁᡤ⇕ఏ㐩⋡ h ࡣᘧ(2)࡛ồࡵࡓ㸬
h q Twall  Tsat(2)(6)ࡇࡇ࡛ Tsat ࡣ㣬࿴ ᗘ࡛࠶ࡾ㸪≀ᛶ್ィ⟬ࣉࣟࢢ࣒ࣛ Propath ࢆ⏝࠸࡚㸪⵨Ⓨჾධཱྀᅽຊ࡟࠾ࡅࡿ್ࢆィ⟬ࡋࡓ㸬
Twall ࡣቨ㠃 ᗘ࡛࠶ࡿ㸬ࡲࡓ㸪ᒁᡤࡢ஝ࡁᗘ x ࡣ㸪ᒁᡤ࢚ࣥࢱࣝࣆ࣮i ࠿ࡽ Propath(6)ࢆ⏝࠸࡚ồࡵࡓ㸬
2࣭4 ᐇ㦂᮲௳ᮏ◊✲ࡢᐇ㦂᮲௳࡜ࡋ࡚㸪㉁㔞ὶ᮰ G = 5, 7.5 kg/m2s㸪ὶ㊰㧗ࡉ δ = 1, 2, 5 mm㸪ᖹᆒ⇕ὶ᮰ q = 10, 15, 20 kW/m2㸪㣬࿴ᅽຊ Psat = 0.7, 0.9 MPa ࢆ୚࠼ࡓ㸬

Fig. 4 Location of thermocouples.

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小山幸平，千代田紘享，有馬博史，岡本明夫，池上康之

3. ⤖ᯝ࠾ࡼࡧ⪃ᐹ3࣭1 ㉁㔞ὶ᮰ࡢᙳ㡪ᅗ 5 ࡟㸪㉁㔞ὶ᮰ G = 5 ࠾ࡼࡧ 7.5 kg/m2s ࡢ᮲௳ୗ࡟࠾ࡅࡿ⇕ᖹ⾮஝ࡁᗘ࡜⇕ఏ㐩⋡ࡢ㛵ಀࢆ♧ࡍ㸬ᐇ㦂᮲௳ࡣ㸪ὶ㊰㧗ࡉ δ = 1 mm㸪⇕ὶ᮰ q = 10 kW/m2 ࠾ࡼࡧ㣬࿴ᅽຊ Psat = 0.7 MPa ࡛࠶ࡿ㸬⇕ఏ㐩⋡ࡣ㸪Ἓ㦐ࡢ㛤ጞ࡟క࠸㸪x < 0.3 ࡟࠾࠸࡚ᛴ⃭࡟ቑຍࡋ࡚࠸ࡿ㸬୍᪉㸪x > 0.3 ࡛ࡣ㸪஝ࡁᗘࡀቑຍ
ࡋ࡚ࡶ⇕ఏ㐩⋡ࡢ್࡟ኚ໬ࡣぢࡽࢀ࡞࠸㸬ࡲࡓ㸪ᮏ◊✲ࡢᐇ㦂⠊ᅖ࡛ࡣ㸪ࡑࢀࡒࢀᐇ㦂᮲௳࡟࠾࠸࡚㸪సື
ὶయࡢ㉁㔞ὶ᮰ࡀ⇕ఏ㐩⋡࡟୚࠼ࡿᙳ㡪ࡣࡳࡽࢀ࡞࠿
ࡗࡓ㸬ࡇࡢ⤖ᯝࡣ㸪సືὶయࡢὶ㏿࡟㉳ᅉࡍࡿ࡜⪃࠼ࡽࢀࡿ㸬సືὶయࡍ࡭࡚ࡀᾮ┦࡜ࡋ࡚ὶࢀࡓ࡜௬ᐃࡍ
ࡿ࡜㸪ᅗ 5 ࡢ G = 5 kg/m2s ࡢሙྜ㸪సືὶయࡢὶ㏿ࡣ
8 mm/s㸪G = 7.5 kg/m2s ࡢሙྜࡢὶ㏿ࡣ 12 mm/s ࡜ప㏿࡛࠶ࡿ㸬ࡇࡢࡓࡵ㸪ᮏ◊✲࡟࠾࠸࡚ࡣ㸪ᑐὶࡼࡾࡶẼ

Fig. 5 The effect of mass flux on heat transfer coefficient(δ = 1 mm, q = 10 kW/m2, Psat = 0.7 MPa).

Ἳࡢᣲືࡀ⇕⛣ືࢆᨭ㓄ࡋ࡚࠸ࡿ࡜ࡳࡽࢀ㸪㉁㔞ὶ᮰ࡢᙳ㡪ࡀほᐹࡉࢀ࡞࠿ࡗࡓࡶࡢ࡜⪃࠼ࡽࢀࡿ㸬3࣭2 ⇕ὶ᮰ࡢᙳ㡪ᅗ 6 ࡟㸪⇕ὶ᮰ q = 10㸪15 ࠾ࡼࡧ 20 kW/m2 ࡢ᮲௳ୗ࡟࠾ࡅࡿ⇕ᖹ⾮஝ࡁᗘ࡜⇕ఏ㐩⋡ࡢ㛵ಀࢆ♧ࡍ㸬ᅗ 6(a)ࡣ㉁㔞ὶ᮰ G = 5 kg/m2s ࠾ࡼࡧὶ㊰㧗ࡉ δ = 1 mm ࡛㸪୍᪉㸪ᅗ 6(b)ࡣ㸪ᅗ 6(a)ࡼࡾࡶὶ㊰ࡀ㧗࠸ሙྜ㸦δ = 5 mm㸧ࡢ⤖ᯝ࡛࠶ࡿ㸬ᅗ 6(a)࡟࠾࠸࡚㸪⇕ὶ᮰ࡢቑຍ࡟క࠸⇕ఏ㐩⋡ࡀቑຍࡋ࡚࠸ࡿ㸬ࡇࢀࡣ㸪⇕ὶ᮰ࡢቑຍ࡟ࡼࡾ㸪ఏ⇕㠃ୖࡢⓎ
ἻⅬ࠾ࡼࡧẼἻⓎ⏕ࡢ࿘ᮇࡀቑຍࡋࡓࡇ࡜㸪ࡲࡓἛ㦐࡟క࠸Ⓨ⏕ࡋࡓẼἻ࡟ࡼࡾ㸪ὶ㊰ෆࡢసືὶయࡀ᧠ᢾࡉࢀࡓࡇ࡜࡟ࡼࡿຠᯝ࡜⪃࠼ࡽࢀࡿ㸬୍᪉㸪ὶ㊰㧗ࡉࡀ㧗࠸ᅗ 6(b)࡛ࡣ㸪⇕ఏ㐩⋡ࡢ್ࡣ⇕ὶ᮰ࡢᙳ㡪ࢆཷࡅ࡞࠸㸬ὶ㊰ࡀ㧗࠸ሙྜ㸪ὶ㊰࡟༨ࡵࡿẼἻࡢయ✚ࡀ┦ᑐⓗ࡟ᑠࡉࡃ࡞ࡿࡓࡵ㸪⇕ఏ㐩⋡ࡀἛ㦐࡟క࠸Ⓨ⏕ࡍࡿẼἻࡢᣲືࡢᙳ㡪ࢆཷࡅ࡟ࡃࡃ࡞ࡗࡓࡇ࡜࡟ࡼࡿ࡜⪃࠼ࡽࢀࡿ㸬ࣉ࣮ࣞࢺᘧ⵨Ⓨჾ࡟࠾࠸࡚㸪⇕ఏ㐩⋡ࡀ⇕ὶ᮰ࡢᙳ㡪ࢆཷࡅࡿ๭ྜࡣ㸪ὶ㊰㧗ࡉ࡟౫Ꮡࡋ࡚࠸ࡿ࡜࠸࠼ࡿ㸬3࣭3 ὶ㊰㧗ࡉࡢᙳ㡪
ᅗ 7 ࡟㸪ὶ㊰㧗ࡉ δ = 1㸪2 ࠾ࡼࡧ 5 mm ࡢ᮲௳ୗ࡟࠾ࡅࡿ⇕ᖹ⾮஝ࡁᗘ࡜⇕ఏ㐩⋡ࡢ㛵ಀࢆ♧ࡍ㸬ᐇ㦂᮲௳ࡣ㸪(a) G = 5 kg/m2s, δ = 1 mm, Psat = 0.7 MPa.

(b) G = 5 kg/m2s, δ = 5 mm, Psat = 0.7 MPa.

Fig. 6 The effect of heat flux on heat transfer coefficient.

伝熱面に微細な凹凸を有するプレート式蒸発器のアンモニア流動沸騰熱伝達に関する研究

35㉁㔞ὶ᮰ G = 5 kg/m2s ⇕ὶ᮰ q = 10 kW/m2 ࡛࠶ࡿ㸬
ὶ㊰㧗ࡉࢆ 5 mm ࠿ࡽ 2 mm ࡟ῶᑡࡉࡏ࡚ࡶ⇕ఏ㐩⋡ࡢ್࡟኱ࡁ࡞ᕪ␗ࡀࡳࡽࢀ࡞࠸୍᪉㸪2 mm ࠿ࡽ 1 mm ࡬ῶᑡࡉࡏࡓ࡜ࡁ࡟ࡣ㸪⇕ఏ㐩⋡ࡣ኱ᖜ࡟ቑຍࡋ࡚࠸ࡿ㸬ὶ㊰ࡀ⊃࠸ሙྜ㸪Ἓ㦐࡟ࡼࡾⓎ⏕ࡋࡓẼἻࡀὶ㊰᩿㠃ࢆ࡯ࡰ༨᭷ࡋ㸪࠸ࢃࡺࡿ confined bubble ࡜࿧ࡤࢀࡿ≧ែ࡟࡞ࡿ㸬ࡇࡢ࡜ࡁఏ⇕㠃ୖ࡟ࡣ㸪సືὶయࡢⷧ࠸ᾮ⭷ࡀᙧᡂࡉࢀࡿ㸬ࡇࢀ࡟ࡼࡾ㸪ὶ㊰㧗ࡉࡀప࠸ሙྜ㸪⇕ఏ㐩⋡ࡣ኱ࡁ࡞್ࢆ࡜ࡿࡼ࠺࡟࡞ࡿ࡜⪃࠼ࡽࢀࡿ㸬୍᪉㸪ὶ㊰㧗ࡉࡀ 5 mm ࠾ࡼࡧ 2 mm ࡢሙྜ㸪ẼἻࡣᏙ❧ẼἻࡢ≧ែ࡟࠶ࡿ࡜ࡳࡽࢀ㸪ఏ⇕㠃ୖ࡟ୖ㏙ࡢࡼ࠺࡞ⷧ࠸ᾮ⭷ࡣᙧᡂࡉࢀ࡟ࡃ࠸㸬ࡑࡢࡓࡵ㸪ఏ⇕ಁ㐍ຠᯝࡀᚓࡽࢀ࡞࠿ࡗࡓࡶࡢ࡜⪃࠼ࡽࢀࡿ㸬࡞࠾㸪ὶ㊰ෆ㒊࡟࠾ࡅࡿẼἻࡢᙧ≧ࡸᣲື࡞࡝ࡢヲ⣽ࢆ⌮ゎࡍࡿࡓࡵ࡟㸪ὶ㊰ෆ㒊ࡢྍど໬ᐇ㦂ࡀồࡵࡽࢀࡿ㸬
3࣭4 㣬࿴ᅽຊࡢᙳ㡪ᅗ 8 ࡟㸪㣬࿴ᅽຊ Psat = 0.7 MPa ࠾ࡼࡧ 0.9 MPa ࡢ᮲௳ୗ࡟࠾ࡅࡿ⇕ᖹ⾮஝ࡁᗘ࡜⇕ఏ㐩⋡ࡢ㛵ಀࢆ♧ࡍ㸬ᐇ㦂᮲௳ࡣ㉁㔞ὶ᮰ G = 5 kg/m2s㸪ὶ㊰㧗ࡉ δ = 1 mm ࠾ࡼࡧ⇕ὶ᮰ q = 10 kW/m2 ࡛࠶ࡿ㸬ᮏ◊✲ࡢᐇ㦂⠊ᅖ࡟࠾࠸࡚ࡣ㸪ᐇ㦂᮲௳࡟㛵ࢃࡽࡎ㸪⇕ఏ㐩⋡ࡣ㣬࿴ᅽຊࡢᙳ㡪ࢆཷࡅ࡞࠿ࡗࡓ㸬ࡇࢀࡣ㸪0.7MPa ࠾ࡼࡧ 0.9 MPa ࡟࠾ࡅࡿᐦᗘ㸪⢓ᗘ㸪ẚ⇕㸪⇕ఏᑟ⋡ࡢ್࡟኱ࡁ࡞ᕪ␗ࡀ࡞࠸ࡓࡵ࡜⪃࠼ࡽࢀࡿ㸬⾲ 1 ࡟㸪Propath(6)࡟ࡼࡗ࡚ồࡵࡓྛ≀ᛶ್ࢆ♧ࡍ㸬
3࣭5 ఏ⇕㠃ୖࡢพฝࡢᙳ㡪ᮏ◊✲࡛ࡣ㸪ࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢఏ⇕ಁ㐍ࢆ┠ⓗ࡜ࡋ㸪ఏ⇕㠃ୖ࡟ᚤ⣽࡞พฝຍᕤࢆ᪋ࡋࡓ㸬ࡇࡇ࡛㸪พฝࡢ᭷↓ࡀ⇕ఏ㐩⋡࡟୚࠼ࡿᙳ㡪ࢆ♧ࡍ㸬ᅗ 9 ࡣ㸪㉁⾲㠃࡟พฝຍᕤࢆ᪋ࡋࡓఏ⇕㠃ࢆ⏝࠸࡚ᮏ◊✲࡛ᚓࡽࢀࡓ⇕ఏ㐩⋡࡜㸪௨๓ࡢ◊✲(7)࡟࠾࠸࡚㸪ఏ⇕㠃⾲㠃ࡀᖹᆒ⾲㠃⢒ࡉ 0.6 μm ࡢ㙾㠃௙ୖࡆຍᕤࢆ᪋ࡋࡓఏ⇕㠃ࢆ⏝࠸࡚ᚓࡽࢀࡓ⇕ఏ㐩⋡࡜ࡢẚ㍑࡛࠶ࡿ㸬࡞࠾㸪ᅗ 9 ࡢᐇ㦂᮲௳ࡣ㸪㔞ὶ᮰ G = 5 kg/m2s㸪ὶ㊰㧗ࡉ δ = 1 mm㸪⇕ὶ᮰ q =10 kW/m2㸪㣬࿴ᅽຊ Psat = 0.7 MPa ࡛࠶ࡿ㸬x < 0.1 ࡟࠾࠸࡚㸪⇕ఏ㐩⋡ࡣఏ⇕㠃ୖࡢพฝࡢᙳ㡪ࢆཷࡅ࡞࠸㸬ࡇࡢ㡿ᇦ࡛ࡣ㸪Ἓ㦐࡟ࡼࡿẼἻⓎ⏕ࡣࡉ࡯࡝
άⓎ࡛ࡣ࡞࠸ࡇ࡜ࡀண᝿ࡉࢀ㸪ᾮ┦ࡀὶ㊰ࡢ኱༙ࢆ༨ࡵ࡚࠸ࡿ࡜⪃࠼ࡽࢀࡿ㸬ఏ⇕㠃ୖ࡟พฝࢆ௜୚ࡋࡓࡇ࡜࡟
ࡼࡾఏ⇕㠃✚ࡀቑຍࡍࡿࡀ㸪సືὶయࡢὶࢀ᪉ྥ 1 mm ࠶ࡓࡾࡢఏ⇕㠃✚ቑຍ㔞ࡣ㸪0.2 cm2/mm ࡛࠶ࡿ㸬ఏ⇕㠃Table 1 Thermophysical properties of ammonia.
Phase

Saturation pressure Density Viscosity(MPa)(kg/m3) (Pas)619

1.63×10-44720

0.9607-4

1.51×104781

0.489

0.7

5.51

1.09×10-5828

2.49㽢10-2

0.9

7.02

1.12×10-5677

2.67㽢10-2

0.7

LiquidVapor

Specific heat at constant Thermal conductivitypressure (J/kgK)(W/mK)

Fig. 7 The effect of channel height on heat transfer
22

coefficient (G = 5 kg/m s, q = 10 kW/m , Psat = 0.7 MPa).

0.507

Fig. 8 The effect of saturation pressure on heat transfer
coefficient (G = 5 kg/m2s, δ = 1 mm , q = 10 kW/m2).

36

小山幸平，千代田紘享，有馬博史，岡本明夫，池上康之✚ࡢቑຍ㔞ࡀẚ㍑ⓗᑡ࡞࠸ࡓࡵ㸪ᾮ┦ࡀᨭ㓄ⓗ࡞ࡇࡢ㡿ᇦ࡛ࡣఏ⇕ಁ㐍ࡢຠᯝࡀᚓࡽࢀ࡞࠿ࡗࡓ࡜⪃࠼ࡽࢀࡿ㸬୍᪉㸪x > 0.1 ࡟࠾࠸࡚㸪⇕ఏ㐩⋡ࡣఏ⇕㠃࡟พฝࢆ᭷ࡍࡿ᪉ࡀ኱ࡁࡃ࡞ࡗ࡚࠸ࡿ㸬ࡇࢀࡣ㸪ఏ⇕㠃ࡢ⾲㠃࡟พฝࢆ௜୚ࡋࡓࡇ࡜࡛㸪ⓎἻⅬࡀቑຍࡋ㸪Ἓ㦐ࡀάⓎ໬ࡋࡓࡇ࡜࡟ࡼࡿ࡜⪃࠼ࡽࢀࡿ㸬ᮏ◊✲࡛⏝࠸ࡓพฝࡘࡁࡢఏ⇕㠃ࡣ㸪พฝࡢୖ㠃ࡣ㙾㠃௙ୖࡆ࡜࡞ࡗ࡚࠸ࡿࡀ㸪ഃ㠃࠾ࡼࡧᗏ㠃࡟ࡘ࠸࡚ࡣ㙾㠃௙ୖࡆຍᕤࢆ⾜ࡗ࡚࠸࡞࠸㸬ࡑࡢࡓࡵ㸪ഃ㠃࠾ࡼࡧᗏ㠃ࡢ⾲㠃⢒ࡉࡣ኱ࡁࡃ࡞ࡗ࡚࠾ࡾ㸪ࡇࡢࡇ࡜࡟ࡼࡗ࡚ⓎἻⅬࡢቑຍࡀᘬࡁ㉳ࡇࡉࢀࡓࡶࡢ࡜⪃࠼ࡽࢀࡿ㸬ࡇࢀࡽࡢ⤖ᯝ㸪ఏ⇕㠃࡟ᚤ⣽࡞พฝຍᕤࢆ᪋ࡋࡓሙྜࡢ⇕ఏ㐩⋡ࡀ㧗ࡃ࡞ࡗࡓ࡜⪃࠼ࡽࢀࡿ㸬

Fig. 9 Comparison of heat transfer coefficient between
smooth and grooved channels (G = 5 kg/m2s, δ = 1mm , q = 10 kW/m2, Psat = 0.7 MPa).

4.
 ⤖   ㄽసືὶయ࡟࢔ࣥࣔࢽ࢔ࢆ⏝࠸ࡓࣉ࣮ࣞࢺᘧ⵨Ⓨჾ࡟࠾࠸࡚㸪ఏ⇕㠃ୖ࡟ᚤ⣽࡞พฝຍᕤࢆ᪋ࡋࡓఏ⇕㠃ࢆ⏝࠸㸪ࡑࡢఏ⇕≉ᛶ࡟୚࠼ࡿ㉁㔞ὶ᮰㸪ὶ㊰㧗ࡉ㸪⇕ὶ᮰࠾ࡼࡧ㣬࿴ᅽຊࡢᙳ㡪ࢆ᳨ウࡋࡓ㸬ࡲࡓ㸪ఏ⇕㠃࡟ᚤ⣽࡞พฝࢆ௜୚ࡍࡿࡇ࡜࡟ࡼࡿఏ⇕ಁ㐍ຠᯝࢆ᳨ウࡋࡓ㸬ᮏ◊✲ࡢ⤖ㄽࡣ௨ୗࡢ㏻ࡾ࡛࠶ࡿ㸬㸦1㸧ᮏ◊✲ࡢᐇ㦂⠊ᅖ࡟࠾࠸࡚㸪⇕ఏ㐩⋡ࡣ㉁㔞ὶ᮰ࡢᙳ㡪ࢆཷࡅ࡞࠸㸬
㸦2㸧ࣉ࣮ࣞࢺᘧ⵨Ⓨჾ࡟࠾࠸࡚㸪⇕ఏ㐩⋡ࡀ⇕ὶ᮰ࡢᙳ㡪ࢆཷࡅࡿ๭ྜࡣ㸪ὶ㊰㧗ࡉ࡟౫Ꮡࡋ࡚࠸ࡿ㸬㸦3㸧ὶ㊰㧗ࡉࡀప࠸ሙྜ㸪confined bubble ࡢຠᯝ࡟ࡼࡾ㸪ఏ⇕㠃ୖ࡟ⷧ࠸ᾮ⭷ࡀᙧᡂࡉࢀ㸪⇕ఏ㐩⋡ࡀቑຍࡍࡿ㸬୍᪉㸪ὶ㊰㧗ࡉࡀ㧗࠸ሙྜ㸪ẼἻࡣᏙ❧ẼἻ࡜࡞ࡾ㸪ὶ㊰㧗ࡉࡣ⇕ఏ㐩⋡࡟ᙳ㡪ࡋ࡞࠸㸬
㸦4㸧ᮏ◊✲ࡢᐇ㦂⠊ᅖ࡟࠾࠸࡚㸪⇕ఏ㐩⋡ࡣ㣬࿴ᅽຊࡢᙳ㡪ࢆཷࡅ࡞࠸㸬
㸦5㸧ࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢఏ⇕㠃ୖ࡟ᚤ⣽࡞พฝࢆ௜୚ࡍࡿࡇ࡜࡛㸪ⓎἻⅬࡀቑຍࡋ㸪⇕ఏ㐩⋡ࡀቑຍࡍࡿ㸬ᩥ   ⊩(1) ᷸㒊ගኸ㸪ụୖᗣஅ㸪㛛ฟᨻ๎㸪ୖཎ᫓⏨㸪͆ࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢ࢔ࣥࣔࢽ࢔ᖹᆒ⵨Ⓨ⇕ఏ㐩࡜ Ỉഃᅽຊᦆኻ͇
㸪᪥ᮏ෭෾✵ㄪᏛ఍ㄽᩥ㞟㸪Vol. 22, No. 4 (2005), pp. 403-415.
(2) Arima, H., Kim, J. H., Okamoto, A., and Ikegami, Y., “Local boiling heat transfer characteristics of ammonia in a vertical plateevaporator”, International Journal of Refrigeration, Vol. 33, No. 2 (2010), pp. 359-370.
(3) ᭷㤿༤ྐ㸪ụୖᗣஅ㸪ᯇᑿఙᙪ㸪ᇳ⾜ၨኴ㸪ᒸᮏ᫂ኵ㸪͆ࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢ⾲㠃ᚤ⣽ຍᕤ࡟ࡼࡿ࢔ࣥࣔࢽ࢔Ἓ㦐⇕ఏ㐩ಁ㐍 (พฝ⁁ࡢྥࡁ࡟ࡼࡿᙳ㡪)͇
㸪OTEC㸪No. 15 (2010), pp. 19-26.
(4) ᒸᮏ᫂ኵ㸪᭷㤿༤ྐ㸪ụୖᗣஅ㸪͆ᚤ⣽พฝ㠃ࢆ᭷ࡍࡿࢳࢱࣥ〇ࣉ࣮ࣞࢺᘧ⵨Ⓨჾ࡟࠾ࡅࡿ࢔ࣥࣔࢽ࢔ࡢἛ㦐⇕ఏ㐩ಁ㐍͇
㸪R&D/⚄ᡞ〇㗰ᢏሗ㸪Vol. 60, No. 2 (2010), pp. 60-65.
(5) Alam, T., Lee, P. S., and Yap, C. R., “Effects of surface roughness on flow boiling in silicon microgap heat sinks”,
International Journal of Heat and Mass Transfer, Vol. 64 (2013), pp. 28-41.
(6) http://www.rccm.co.jp/product/fluid/propath/(7) ༓௦⏣⣫ா㸪᭷㤿༤ྐ㸪ᑠᒣᖾᖹ㸪ụୖᗣஅ㸪͆ࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢὶ㊰㛫㝸࡟ࡼࡿ⇕ఏ㐩࡬ࡢᙳ㡪࡜᥎⟬ᘧࡢᥦ᱌͇㸪OTEC㸪No. 17 (2012), pp. 15-24.

