ＯＴＥＣVol. 18 (2013)，23〜29

3 重円筒型アンモニア蒸発器に関する研究3 㔜෇⟄ᆺ࢔ࣥࣔࢽ࢔⵨Ⓨჾ࡟㛵ࡍࡿ◊✲㸨᭷㤿 ༤ྐ*1㸪ᩗᡂྩ*2㸪ᑠᒣ ᖾᖹ*1
Study on three-tube type evaporator for ammonia
Hirofumi ARIMA*1, Jing Cheng-Jun*2 and Kohei KOYAMA*1*1

Institute of Ocean energy, Saga University
1-48, Hirao, Kubara-aza, Yamashiro-mach, Imari-shi, Saga, 849-4256, JapanAs a study of plate evaporator using ammonia as a working fluid, measurement of overall and boiling heat transfer
coefficient are mainly performed for OTEC and ammonia refrigerator. On the other hand, there is a few research of ammoniaboiling on heat exchanger except of plate type one. On this present study, in order to propose a new type heat exchanger for
OTEC in Lieu of plate type one, a three-tube type heat exchanger is developed and performance of that is evaluated.
Measurement of overall heat transfer coefficient on the three-tube heat exchanger which heat exchanged between flowing theammonia and hot water at a range of mass flow rate of ammonia (mWF = 1.7 ~ 5.410-3 kg/s), mass flow rate of hot water(mWS = 0.016 ~ 0.61 kg/s), averaged heat fluxes (qav = 7.6 ~ 24.7 kW/m2), and pressures (Psat = 0.7 MPa). The result derived
that the relationship between overall heat transfer coefficient and velocity of hot water. In addition, comparisons between heattransfer coefficient of boiling ammonia and hot water, and correlations. It is found that the performance of new heatexchanger is lower than that of plate type.
Key Words : Three-tube Heat Exchanger, Ammonia, Evaporator, Overall Heat Transfer Coefficient ⥴   ゝᾏὒ ᗘᕪⓎ㟁࡛ࡣసືὶయ࡟࢔ࣥࣔࢽ࢔㸪⇕஺᥮ჾ࡟ࣉ࣮ࣞࢺᘧ⇕஺᥮ჾࢆ᥇⏝ࡋ࡚࠸ࡿ㸬ࡇࡢ⌮⏤࡜ࡋ࡚㸪⇕※࡛࠶ࡿ ෭ᾏỈࡢ ᗘ࡜ࡑࡢ ᗘᕪࡀ㠀ᖖ࡟ᑠࡉ࠸ࡇ࡜ࡀᣲࡆࡽࢀࡿ㸬ࣉ࣮ࣞࢺᘧ⇕஺᥮ჾࡣ㸪⟶ᆺࡢ⇕஺᥮ჾ࡟ẚ࡭࡚༢఩య✚ᙜࡓࡾࡢఏ⇕㠃✚ࡀ኱ࡁࡃ࡛ࡁࡿࡇ࡜㸪࣓ࣥࢸࢼࣥࢫᛶࡀ㧗࠸ࡇ࡜ࡀ฼Ⅼ࡜ࡋ࡚ᣲࡆࡽࢀࡿ㸬࡜ࡇࢁ࡛㸪⇕஺᥮ჾࡢᛶ⬟ࡣ⵨Ⓨჾࡸจ⦰ჾࡢ⇕㏻㐣⋡ࡸἛ㦐࣭จ⦰⇕ఏ㐩⋡㸪⇕※ഃࡢ⇕ఏ㐩⋡㸪ᅽຊᦆኻ࡞࡝࡟ࡼࡗ࡚ホ౯ࡉࢀࡿ㸬⌧ᅾࡇࢀࡽࡢᛶ⬟ホ౯࡟ࡘ࠸࡚㸪OTEC ࡸ࢔ࣥࣔࢽ࢔෭෾ᶵ࡛ࡣ࢔ࣥࣔࢽ࢔ࢆసື
ὶయ࡜ࡍࡿࣉ࣮ࣞࢺᘧ⇕஺᥮ჾ࡟ࡘ࠸࡚ᩘከࡃሗ࿌(1)(2)(3)ࡉࢀ࡚࠸ࡿ㸬୍᪉㸪ࣉ࣮ࣞࢺᘧ௨እ࡟ࡘ࠸࡚ࡣ㸪࢔ࣥࣔࢽ࢔ࢆ⏝࠸ࡓ෇⟶ࡢἛ㦐⇕ఏ㐩࡟ࡘ࠸࡚ࡀᩘከࡃ◊✲ࡉࢀ࡚࠸ࡿ(4)(5)ࡀ㸪ࡑࢀ௨እࡢ⇕஺᥮ჾ࡟ࡘ࠸࡚ࡣ࠶ࡲࡾሗ࿌ࡉࢀ࡚࠸࡞࠸㸬ࡑࡇ࡛ᮏ◊✲࡛ࡣࣉ࣮ࣞࢺᘧ࡟ኚࢃࡿ⇕஺᥮ჾࡢᥦ᱌ࡢࡓࡵ㸪᪂ࡓ࡟୕㔜⟶ᘧࡢ⵨Ⓨჾࢆ㛤Ⓨࡋ࡚ࡑࡢᛶ⬟ホ౯ࢆ⾜ࡗࡓ㸬୕㔜෇⟶ࡣ᭱ෆ෇⟶㸪ෆ෇⟶㸪እ෇⟶ࡢ┤ᚄࡢ␗࡞ࡿ 3 ࡘࡢ෇⟶࡛ᵓᡂࡉࢀ㸪ෆ෇⟶࡟࢔ࣥࣔࢽ࢔㸪ࡑࢀ௨እ࡟ Ỉࢆᑐྥ࡟ὶࡍࡇ࡜࡛⇕஺᥮ࢆ⾜࠺㸬࡞࠾㸪ᮏ⿦⨨ࡣ㸪᭱ෆ෇⟶࡜ෆ෇⟶ࢆ୍ࡘࡢࣘࢽࢵࢺ࡜ࡋ࡚እ෇⟶ࡢᐜჾ࡟ᤄධࡋ࡚౑⏝ࡍࡿࡇ࡜ࢆ᝿ᐃࡋ࡚࠸ࡿ㸬ࡑࡢࡓࡵ㸪ᑗ᮶ⓗ࡟኱ᆺࡢእ෇⟶࡟ࡇࡢࣘࢽࢵࢺࢆ」ᩘᤄධࡍࡿࡇ࡜࡛࣓ࣥࢸࢼࣥࢫࡀᐜ᫆࡟࡞ࡿࡇ࡜࠿ࡽࡇࡢᙧ≧ࢆ᥇⏝ࡋࡓ㸬ࡲࡓ㸪┦ᙜ┤ᚄࡀ኱ࡁࡃ࡞ࡿࡇ࡜࠿ࡽ㸪ᅽຊᦆኻࡢపୗ࡟ࡼࡿᛶ⬟ྥୖࢆᮇᚅࡋࡓ㸬ᮏ◊✲࡛ࡣ⇕㏻㐣⋡࠾ࡼࡧ࢔ࣥࣔࢽ࢔࠾ࡼࡧỈࡢ⇕ఏ㐩⋡ࢆồࡵࡿࡇ࡜࡛㸪᪤Ꮡࡢࣉ࣮ࣞࢺᘧࡢ⤖ᯝ࡜ࡢẚ㍑ࢆ⾜ࡗࡓ㸬*ཎ✏ཷ௜ 2013 ᖺ 07 ᭶ 31 ᪥
బ㈡኱Ꮫᾏὒ࢚ࢿࣝࢠ࣮◊✲ࢭࣥࢱ࣮ 㸦ࠛ849-4256 ఀ୓㔛ᕷᒣ௦⏫ஂཎᏐᖹᑿ 1-48㸧
*2୰ᅜ ᅄᕝ኱Ꮫ*1
E-mail: arima@ioes.saga-u.ac.jp
*123

24

有馬博史，敬成君，小山幸平

 グ   ྕA㸸 ఏ⇕㠃✚ [m2]V㸸 ὶ㏿ [m/s]Cp㸸 ᐃᅽẚ⇕ [J/kg K]x㸸 ⇕ᖹ⾮஝ࡁᗘ [-]Dh㸸 Ỉຊ┦ᙜ┤ᚄ [m]G㸸 ㉁㔞ὶ᮰ [kg/m2s]PU㸸 ⢓ᗘ [Pax s]2㸸 ᐦᗘ [kg/m3]h㸸 ⇕ఏ㐩⋡ [W/m K]i㸸 ẚ࢚ࣥࢱࣝࣆ࣮ [J/kg]

ifg

㸸 ⵨Ⓨ₯⇕ [J/kg]k㸸 ⇕ఏᑟ⋡ [W/mK]ῧ࠼Ꮠ㸸 ᖹᆒavm㸸 ㉁㔞ὶ㔞 [kg/s]g㸸 Ẽ┦P㸸 ᅽຊ [Pa]I㸸 ධཱྀPr㸸 ࣉࣛࣥࢺࣝᩘ [-] = PCp/kl㸸 ᾮ┦q2

㸸 ⇕ὶ᮰ [W/m ]lm㸸 ᑐᩘᖹᆒQ㸸 ⇕஺᥮㔞 [W]O㸸 ฟཱྀRe㸸 ࣞ࢖ࣀࣝࢬᩘ [-] =GDh/Psat㸸 㣬࿴t㸸 ෇⟶ࡢཌࡉ [m]sus

㸸 SUS304T㸸ᗘ [Υ]WF㸸 సືὶయWS

㸸U2㸸 ⇕㏻㐣⋡ [W/m K]Ỉ ᐇ   㦂3࣭1 ᐇ㦂⿦⨨
ᅗ 1 ࡟ᐇ㦂⿦⨨ᴫ␎ᅗࢆ♧ࡍ㸬ᐇ㦂⿦⨨ࡣ㸪సືὶయᚠ⎔⣔࡟࠶ࡿ⵨Ⓨჾ(ࢸࢫࢺࢭࢡࢩࣙࣥ)㸪จ⦰ჾ (ᮾிࣈࣞ࢖ࢬ〇 TB-MS11V, ࣈࣞ࢖ࢬࢻ⇕஺᥮ჾ)㸪ࢧࣈࢡ࣮࣮ࣛ (ᮾிࣈࣞ࢖ࢬ〇 TB-MS11V, ࣈࣞ࢖ࢬࢻ⇕஺᥮ჾ)㸪సືὶయࢱࣥࢡ㸪సືὶయ࣏ࣥࣉ (SPECK 〇㸪࣐ࢢࢿࢵࢺ࣏ࣥࣉ㸪NPY-2251MK0402㸪ฟຊ 0.5kW)࡜෭
Ỉᚠ⎔⿦⨨࡛ᵓᡂࡉࢀࡿ㸬 Ỉᚠ⎔⿦⨨࡛ࡣ㸪 Ỉࢱࣥࢡ࡟タ⨨ࡉࢀࡓ 2kW ࣄ࣮ࢱ࣮ (ඵග㟁ᶵ〇 BWA1120)
ࢆ ㄪჾ࡛௵ពࡢ ᗘ࡟ㄪᩚࡋ㸪 Ỉࢆ࣏ࣥࣉ࡛⵨Ⓨჾ࡟ᚠ⎔ࡉࡏ࡚࠸ࡿ㸬෭Ỉᚠ⎔⿦⨨࡛ࡣ㸪෭෾ᶵ I (ᮾⰪ〇RUW-J40001, ෭༷⬟ຊ 400kW)࡜෭෾ᶵ II (࢜ࣜ࢜ࣥ〇 RKW1500B-V-G1, ෭༷⬟ຊ 5.3kW)࡛௵ពࡢ ᗘࡢ෭Ỉࢆసᡂࡋ࡚㸪ࡑࢀࢆ෭Ỉ࣏ࣥࣉ࡛จ⦰ჾ㸪సືὶయࢱࣥࢡ㸪ࢧࣈࢡ࣮࣮ࣛ࡟ᚠ⎔ࡋ࡚సືὶయࡢ෭༷ࢆ⾜ࡗ࡚࠸ࡿ㸬సືὶయᚠ⎔⣔࡟࠾࠸࡚㸪ᾮయࡢసືὶయࡣ࣏ࣥࣉ࡛సືὶయࢱࣥࢡ࠿ࡽ⵨Ⓨჾ࡟㏦ࡽࢀ㸪⵨Ⓨჾ࡟࠾࠸࡚Ỉ࡛ຍ⇕ࡉࢀࡿࡇ࡜࡟ࡼࡗ࡚Ἓ㦐㸪⵨Ⓨࡍࡿ㸬⵨Ⓨჾࢆฟࡓ⵨Ẽࡣ㸪จ⦰ჾ㸪సືὶయࢱࣥࢡ࡛෭༷ࡉࢀ෌ࡧసືὶయࢱࣥࢡ࡟ᡠࡿ㸬ᐇ㦂⿦⨨࡟ࡣ㸪సືὶయ㉁㔞ὶ㔞ィ㸪 ࣭෭Ỉయ✚ὶ㔞ィ㸪 ᗘ㸪ᅽຊࢭࣥࢧ࣮ࢆタ⨨ࡍࡿࡇ࡜࡛ྛ ᐃⅬࡢ≧ែ㔞ࢆ☜ㄆࡋࡓ㸬సືὶయࡢ㉁㔞ὶ㔞 ᐃ࡟ࡣ㸪ࢥࣜ࢜ࣜᘧ㉁㔞ὶ㔞ィ㸦࢚ࣥࢻࣞࢫࣁ࢘ࢨ࣮〇 PROMASS83A ⢭ᗘ s 0.1%௨ෆ㸧㸪 ෭Ỉࡢయ✚ὶ㔞 ᐃ࡟ࡣ㟁☢ὶ㔞ィ㸦࣮࢚࢟ࣥࢫ〇 FD-M ࠾ࡼࡧ FD-P ࢩ࣮ࣜࢬ㸪ᐃ⢭ᗘ s 1.6%㸧
㸪సືὶయ࡜ ෭Ỉࡢ ᗘ ᐃ࡟ࡣ㸪K ᆺࢩ࣮ࢫ⇕㟁ᑐ㸦ᯘ㟁ᕤ〇 ST6㸪ࢡࣛࢫ 1㸪ㄗᕪ s1.5Υ㸧㸪ᅽຊ ᐃ࡟ࡣࢲ࢖࢔ࣇ࣒ࣛᘧᅽຊኚ᥮ჾ㸦ᶓἙ㟁ᶵ〇 FP101㸪 ᐃ⠊ᅖ 0 ~ 2MPa㸪 ᐃ⢭ᗘ s 0.25%㸧
ࢆ౑⏝ࡋࡓ㸬 ᐃ್ࡣ୍᪦࣐ࣝࢳ࣓࣮ࢱ࣮ (Keithley 〇 2701 ᆺ㸪40ch)࡟཰㞟ࡉࢀ㸪ࡇࢀࡽࡢࢧࣥࣉࣜࣥࢢࢹ࣮
ࢱࢆ PC ࡟㌿㏦ࡍࡿࡇ࡜࡛ LabVIEW ࡟࡚⾲♧࠾ࡼࡧグ㘓ࢆ⾜ࡗࡓ㸬ᐇ㦂ࢹ࣮ࢱࡣ㸪ᐃᖖ≧ែࢆ☜ㄆᚋ࡟⣙ 5 ⛊㛫㝸࡛ 3 ศ㛫ࡢグ㘓ࢆ⾜࠸㸪ࡑࡢᖹᆒ್ࢆᐇ㦂್࡜ࡋࡓ㸬ࡲࡓ㸪ྛᐇ㦂᮲௳࡟࠾ࡅࡿࢹ࣮ࢱࡢ෌⌧ᛶࢆ☜ㄆࡍࡿࡓࡵ࡟㸪ᐇ㦂ࢹ࣮ࢱࡣ 3 ᅇࡎࡘグ㘓ࢆ⾜࠸ࡑࢀࡒࢀࡢᖹᆒ್ࡢẚ㍑
ࢆ⾜࠺ࡇ࡜࡛෌⌧ᛶࢆ☜ㄆࡋࡓ㸬࡞࠾㸪ᐃᖖ≧ែࡣ≧ែⅬࡢෆ㸪⵨Ⓨჾධཱྀᅽຊ࡜సືὶయ㉁㔞ὶ㔞ࡀ 5 ศ㛫௨ୖኚືࡋ࡞࠸ࡇ࡜(ධཱྀᅽຊࡣタᐃ್ࡢs1kPa ௨ෆ㸪㉁㔞ὶ㔞ࡣs0.5kg/h ௨ෆ)ࢆ☜ㄆࡋ࡚㸪ᐃᖖ≧ែ࡜ࡋ࡚ࡳ࡞ࡋࡓ㸬
ᅗ 2 ࡟⵨Ⓨჾࡢᶓ᩿㠃ཬࡧ⦪᩿㠃ᅗࢆ♧ࡍ㸬⵨Ⓨჾࡣ SUS304 〇ࡢ 3 㔜෇⟶ࡢᵓ㐀࡛㸪᭱ෆ෇⟶ࡀእᚄ 34mm(25A)㸪ෆ෇⟶ࡀእᚄ 114.3mm (100A)㸪እ෇⟶ࡀእᚄ 216.3mm (200A) ࡢ┤⟶࡛ᵓᡂࡉࢀ࡚࠸ࡿ㸬ࡲࡓ㸪ࡑࢀࡒࢀࡢ෇⟶ࡢ㛗ࡉࡣ㡰␒࡟㸪300, 340, 440 mm ࡛࠶ࡿ㸬సືὶయࡣ᭱ෆ෇⟶̿ෆ෇⟶㛫࡟ὶࡍࡀ㸪ࡑࡢᑟධ㒊ࡣእᚄ
21.7 mm (15A)࠾ࡼࡧ 27.2 mm (20A)ࡢ┤⟶ࢆ౑⏝ࡋࡓ㸬᭱ෆ෇⟶࠾ࡼࡧෆ෇⟶̿እ෇⟶㛫ࡢὶ㊰࡟ Ỉࢆὶࡍࡇ࡜࡛㸪సືὶయ࡜ࡢ㛫࡛⇕஺᥮ࢆ⾜࠺㸬ࡇࡢ᫬ࡢఏ⇕㠃✚ࡣࡑࢀࡒࢀ᭱ෆ෇⟶⾲㠃✚ A1 = 2.7210-2 m2㸪ෆ෇⟶

25

3 重円筒型アンモニア蒸発器に関する研究

Hot water circuit

Working fluid circuit

Cold water circuit

14T

TP TT

21T

T

PTP T13
13
T

312

11

T

56

104

PT

8

9

T

157P

13
1. Test tank (Evaporator) 2. Condenser 3. Working fluid tank 4. Sub cooler
5. Cold water tank 6. Refrigerator I 7. Refrigerator II 8. Hot water tank 9. Working fluid pump 10. Hot water pump
11. Cold water pump 12. Mass flow meter 13. Volumetric flow meter 14. Degassed valve 15. Release valve
Fig. 1 Schematic diagram of the experimental apparatus
Heat transfer
surface area
A1A2㻠㻠㻜㻟㻠㻜㻟㻜㻜

A3H2O flow

Support

NH3channel

NH3 flowT

H2Ooutlet

H2O inlet

㻝㻣

㻟㻠㻞㻝㻢

㻝㻝㻠

㻞㻞

NH3 outlet

NH3 inlet
T PH 2Ochannel
T(a) Cross section(b) Longitudinal section

Fig. 2 Schematic diagram of the evaporator (test section)

⾲㠃✚ A2 = 9.1310-2 m2㸪෇⎔㒊⾲㠃✚ A3 = 1.8610-2 m2㸪⥲ఏ⇕㠃✚ A=13.7110-2 m2 ࡛࠶ࡿ㸬ࡲࡓ㸪┦ᙜ┤ᚄࡣὶ㊰᩿㠃✚࡜࿘㛗࠿ࡽ Dh = 9.5610-2 m ࡜ࡋࡓ㸬

26有馬博史，敬成君，小山幸平

3࣭
࣭2 ⇕㏻㐣⋡㸪⇕ᖹ⾮஝ࡁᗘࡢᩚ⌮సືὶయࡢ⇕㏻㐣⋡ U ࡜⇕ᖹ⾮஝ࡁᗘ x ࡟ࡘ࠸࡚ồࡵࡿࡓࡵ㸪௨ୗࡢᡭ㡰࡛ィ⟬ࢆ⾜ࡗࡓ㸬ึࡵ࡟㸪⇕஺᥮ჾࡢ⇕㏻㐣⋡ U㸪ఏ⇕㠃✚ A ࡜⇕஺᥮㔞 Q ࡢ㛵ಀࡣḟᘧ࡛ᐃ⩏ࡉࢀࡿ㸬

Q UA'Tlm(1)

ࡇࡇ࡛'Tlm ࡣᑐᩘᖹᆒ ᗘᕪ࡛࠶ࡾ㸪ḟᘧ࡛ᐃ⩏ࡉࢀࡿ㸬

'Tlm

TWSI  TWSO
§ T  Tsat ·¸¸ln ¨¨ WSI© TWSO  Tsat ¹(2)ࡇࡇ࡛㸪TWSI㸪TWSO ࡣ Ỉධཱྀ࠾ࡼࡧฟཱྀ ᗘ㸪Tsat ࡣసືὶయࡢ㣬࿴ ᗘࢆ♧ࡍ㸬࡞࠾㸪㣬࿴ ᗘ Tsat ࡣ⵨Ⓨჾධཱྀࡢᅽຊࢆ㣬࿴ᅽຊ Psat ࡜௬ᐃࡋࡓ᫬ࡢ㣬࿴ ᗘࢆ♧ࡋ࡚࠸ࡿ㸬ࡲࡓ㸪㣬࿴ ᗘࡢ⟬ฟ࡟ࡣ P-Propath(6)ࢆ⏝࠸ࡓ㸬ࡲࡓ㸪సືὶయ࡜ Ỉ࡜ࡢ㛫ࡢఏ⇕ࡣ㸪᭱ෆ෇⟶ࡢ⾲㠃 A1㸪ෆ෇⟶ࡢ⾲㠃 A2 ࠾ࡼࡧ㸪ෆ⟶ഃ㠃ࡢ෇⎔㒊ศ A3 ࢆ㏻ࡋ࡚⾜ࢃࢀࡿࡓࡵ㸪ఏ⇕㠃✚ A ࡣ A1 ~ A3 ࡢ࿴ࢆ⏝࠸ࡓ㸬࡜ࡇࢁ࡛㸪ᘧ(2)ࡣᑐྥὶࡢ⇕஺᥮ჾ࡟࠾ࡅࡿᑐᩘᖹᆒ ᗘᕪࡢᘧ࡛࠶ࡿ㸬ᮏ⵨Ⓨჾ࡛ࡣసືὶయධཱྀ࡜ Ỉධཱྀ࠿ࡽὶධࡍࡿࡑࢀࡒࢀࡢὶయࡢྥࡁࡣྠ୍࡛࠶ࡿࡀ㸪సືὶయฟཱྀ࡟ᑐࡋ࡚ Ỉࡣ㏫ྥࡁࡢὶࢀ࡜࡞ࡿࡇ࡜࠿ࡽἛ㦐ᚋࡢ⇕ఏ㐩ࡢᙳ㡪ࢆ⪃៖ࡍࡿࡓࡵᑐᩘᖹᆒ ᗘᕪ࡟ࡣᑐྥὶࡢᘧࢆ᥇⏝ࡋࡓ㸬ḟ࡟㸪⇕஺᥮㔞 Q ࡣ Ỉࡢධཱྀฟཱྀࡢ ᗘᕪࢆ฼⏝ࡋ࡚ḟࡢࡼ࠺࡟ᐃ⩏ࡋࡓ㸬

Q mWS CpWS 'TmWS CpWS TWSI  TWSO(3)ࡇࡇ࡛㸪mWS ࡣ Ỉࡢ㉁㔞ὶ㔞㸪CpWS ࡣ Ỉࡢᐃᅽẚ⇕࡛࠶ࡿ㸬ḟ࡟㸪ᖹᆒ⇕ὶ᮰ qav ࡣḟᘧ࡛ᐃ⩏ࡍࡿ㸬qav Q / A(4)ḟ࡟㸪⵨Ⓨჾฟཱྀ࡟࠾ࡅࡿ⇕ᖹ⾮஝ࡁᗘ x ࡣ௨ୗࡢ᪉ἲ࡛⟬ฟࡋࡓ㸬ࡲࡎ㸪⵨Ⓨჾฟཱྀࡢẚ࢚ࣥࢱࣝࣆ࣮iO ࢆ
ධཱྀࡢẚ࢚ࣥࢱࣝࣆ࣮iI㸪⇕஺᥮㔞 Q㸪సືὶయࡢ㉁㔞ὶ᮰ mWF ࠿ࡽḟᘧ࡛ồࡵࡿ㸬

iOiI  Q / mWF(5)࡞࠾㸪iin ࡟ࡘ࠸࡚ࡣ⵨Ⓨჾධཱྀࡢᅽຊ࡜ ᗘ࠿ࡽ P-Propath(6)ࢆ౑ࡗ࡚ồࡵࡓ㸬iout ࢆ⏝࠸࡚㸪ḟᘧ࡛ฟཱྀࡢ⇕ᖹ⾮஝ࡁᗘ x ࢆồࡵࡿ㸬xiO  isat ,l / i fg(6)ࡇࡇ࡛㸪ifg ࡣసືὶయࡢ⵨Ⓨ₯⇕㸪isat, l ࡣ㣬࿴ᾮ࡟࠾ࡅࡿẚ࢚ࣥࢱࣝࣆ࣮࡛࠶ࡿ㸬3࣭3 ᐇ㦂᮲௳ᐇ㦂᮲௳࡜ࡋ࡚㣬࿴ᅽຊ Psat = 0.7 MPa㸪సືὶయࡢ㉁㔞ὶ㔞 mWF = 1.7 ~ 5.410-3 kg/s (㉁㔞ὶ᮰ G = 0.18 ~ 0.58kg/m2s)㸪 Ỉࡢ㉁㔞ὶ㔞 mWS = 0.016 ~ 0.61 kg/s㸪ᖹᆒ⇕ὶ᮰ qav = 7.6 ~ 24.7 kW/m2㸪ฟཱྀ஝ࡁᗘ x = 0.2 ~ 1 ࢆ୚࠼ࡓ㸬

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3 重円筒型アンモニア蒸発器に関する研究 ᐇ㦂⤖ᯝ࠾ࡼࡧ⪃ᐹ4࣭1 ⵨Ⓨჾࡢ⇕㏻㐣⋡ᮏᐇ㦂࡛ᚓࡽࢀࡓసືὶయཬࡧ Ỉධཱྀฟཱྀ ᗘ࠾ࡼࡧὶ㔞ࡼࡾᘧ(1)ࢆ⏝࠸࡚⇕㏻㐣⋡ U ࡢᩚ⌮ࢆ⾜ࡗࡓ㸬ᅗ
3 ࡟ Ỉὶ㏿ VWS ࡟ᑐࡍࡿ⇕㏻㐣⋡ U ࡢࣉࣟࢵࢺࢆ♧ࡍ㸬
ᅗ 3 ࡼࡾὶ㏿ࡢቑຍ࡟క࠸⇕㏻㐣⋡ࡀቑຍࡋ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡿ㸬ࡇࢀࡽࡢഴྥࡣ Ỉࡢὶ㏿ࡀ㏿ࡃ࡞ࡿ࡟క
࠸⇕ఏ㐩ࡀቑຍࡍࡿࡇ࡜࡟ࡼࡿࡶࡢ࡛࠶ࡿ㸬ࡲࡓ VWS < 5 mm/s ࡛ࡣ⇕㏻㐣⋡ࡢᛴ⃭࡞ቑຍ㸪ࡑࢀ௨ୖࡢὶ㏿࡟࡞ࡿ࡜ࡑࡢ໙㓄ࡀ⦆ࡸ࠿࡟࡞ࡗ࡚࠸ࡿࡇ࡜ࡀほᐹࡉࢀࡓ㸬ࡇࡢࣉࣟࢵࢺ࡟ࡘ࠸࡚㸪ḟᘧ࡛ᩚ⌮ࢆ⾜ࡗࡓ㸬

191 .24 ln(VWS )  1641 .3U(7)࡜ࡇࢁ࡛㸪30kWOTEC ⿦⨨࡛⾜ࢃࢀࡓᓊᕝࡽ(7)ࡢ⵨Ⓨჾࡢ◊✲࡛ࡣ㸪⇕㏻㐣⋡ࡣ U = 1000 ~ 3000 W/m2K ࢆ♧ࡋ࡚࠸ࡿ㸬ࡑࢀ࡟ᑐࡋ࡚㸪ᮏᐇ㦂࡛ࡣ U = 200 ~ 1000 W/m2K ࡜ 1/5 ~1/3 ⛬ᗘࡢ⇕㏻㐣⋡࡜࡞ࡗࡓ㸬ࡑࡢ⌮⏤࡜ࡋ࡚㸪ᓊᕝ(7)ࡣ Ỉὶ㏿ VWS ࡜ࡋ࡚ 0.3~0.6 m/s ࢆ୚࠼࡚࠸ࡿࡢ࡟ᑐࡋ࡚㸪ᮏᐇ㦂࡛ࡣࡑࡢ 1/20 ௨ୗࡢὶ㏿ࢆ୚࠼࡚࠸ࡿࡇ࡜࠿ࡽప࠸⇕㏻㐣⋡ࢆ♧ࡋࡓࡶࡢ࡜⪃࠼ࡽࢀࡿ㸬

2

U [W/m K]

1000

500
U=191.24ln(VWS)+1641.3

00

0.01
0.02
VWS [m/s]

0.03

Fig. 3 Overall heat transfer coefficient for hot water velocity

4࣭2Ỉࡢ⇕ఏ㐩⋡Ỉࡢ⇕ఏ㐩⋡ࡢᑟฟࡢࡓࡵ㸪௨ୗࡢ᪉ἲ್࡛ࢆồࡵࡓ㸬ࡲࡎ㸪 Ỉࡢ⇕ఏ㐩⋡ࡢᑟฟ࡟ࡣ Wilson ࣉࣟࢵࢺἲ(8)ࢆ᥇⏝ࡋࡓ㸬Wilson ࣉࣟࢵࢺἲ࡟ࡼࡿ࡜㸪⇕஺᥮ჾࡢ⇕㏻㐣⋡ U ࡜ Ỉࡢὶ㏿ VWS ࡢ㛵ಀ࡟ࡘ࠸࡚ḟᘧ࡛⾲ࡍࡇ࡜ࡀฟ᮶ࡿ㸬

1/ UaVWS0.8  b(8)ࡇࡇ࡛㸪ᅗ 4 ࡟ᮏᐇ㦂࡛ᚓࡽࢀࡓ U ࡜ VWS-0.8 ࡢࣉࣟࢵࢺࢆ♧ࡍ㸬
ᅗ 4 ࡼࡾ 1/U ࡜ VWS-0.8 ࡢ㛵ಀࡣ㸪ᘧ(7)ࡢ⥺ᙧࡢ㛵ಀࢆ♧ࡍࡇ࡜ࡀ᫂ࡽ࠿࡛࠶ࡿ㸬࡞࠾ᅗ 4 ࡼࡾ㸪a㸪b ࡣࡑࢀࡒࢀ a = 7.4810-6㸪b = 1.1010-3 ࢆ♧ࡋࡓ㸬ḟ࡟㸪 Ỉࡢ⇕ఏ㐩⋡ hWS ࠾ࡼࡧసືὶయࡢ⇕ఏ㐩⋡ hWF ࡢ㛵ಀࡣḟᘧ࡛⾲ࡍࡇ࡜ࡀฟ᮶ࡿ㸬

1 / U 1 / hWF  t / ksus  1 / hWS

(9)

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有馬博史，敬成君，小山幸平

0.005
0.004

1/U=(7.48E-6)VWS-0.8+1.10E-3

1/U

0.003
0.002
0.001
Present data
00100

200
VWS-0.8300

400

Fig. 4 1/U vs. VWS-0.8 for Wilson plotࡇࡇ࡛ ksus ࡣ SUS304 〇෇⟶ࡢ⇕ఏᑟ⋡㸪t ࡣ෇⟶ࡢཌࡉࢆ♧ࡍ㸬࡞࠾㸪ィ⟬࡛ࡣ ksus = 17 W/mK, t = 9.4mm ࢆ୚࠼ࡓ㸬࡜ࡇࢁ࡛㸪ksus ࡜ hWF ࡀ୍ᐃ್ࢆྲྀࡿ࡜௬ᐃࡍࡿ࡜㸪ᘧ(8)࡜(9)ࡢ㛵ಀ࠿ࡽ hWS ࡟ࡘ࠸࡚௨ୗࡢ㛵ಀࢆᑟࡃࡇ
࡜ࡀฟ᮶ࡿ㸬

hWS

1 / a VWS0.8(10)ࡲࡓ㸪b t / ksus  1/ hWF

const .

(11)ࡉࡽ࡟㸪ᘧ(10)ࢆ NuWS = hWSDh/kWS ࡢ㛵ಀ࠿ࡽ Nu ᩘ࡛ᩚ⌮ࡍࡿ࡜㸪 Ỉഃࡢ⇕ఏ㐩⋡ࡣḟᘧ࡛⾲ࡍࡇ࡜ࡀฟ᮶ࡿ㸬

NuWS

0.8
1/ 30.918 ReWSPrWS(12)࡞࠾㸪ᘧ(12)ࡣ୍⯡ⓗ࡞෇⟶ෆࡢᙉไᑐὶ⇕ఏ㐩ࡢᘧ࡛࠶ࡿ Dittus-Boelter ࡢᘧ(ᘧ(13))࡟ẚ࡭࡚኱ࡁ࡞್ࢆ♧ࡍࡇ࡜ࡀศ࠿ࡿ㸬

Nu 0.023 Re0.8 Pr 0.4(13)4࣭࣭3 సືὶయࡢ⇕ఏ㐩⋡సືὶయࡢ⇕ఏ㐩⋡ hWF ࡣ㸪ᘧ(9)࡟ U ࠾ࡼࡧᘧ(10)ࡼࡾ hWS ࢆ୚࠼ࡿࡇ࡜࡛ᑟฟࢆ⾜ࡗࡓ㸬ᖹᆒ⇕ὶ᮰ qav ࡜hWF ࡢ㛵ಀࢆᅗ 5 ࡟♧ࡍ㸬
ᅗ 5 ࡼࡾ hWF ࡣ 1000 ~ 4000 W/m2K ࡢ⠊ᅖ࡛ศᕸࡋ࡚࠸ࡿࡇ࡜ࡀศ࠿ࡿ㸬ࡇࢀࡽࡢ್ࡣ㸪᭷㤿ࡽ(2)ࡀồࡵࡓࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢ࢔ࣥࣔࢽ࢔ࡢἛ㦐⇕ఏ㐩⋡ࡢ್࡟ẚ࡭ 1/4~1/2 ࡢప࠸್ࢆ♧ࡋࡓ㸬୍᪉㸪ᓊᕝ(7)࡟ࡼࡿ 30kW OTEC ⏝ࡢࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡢ࢔ࣥࣔࢽ࢔Ἓ㦐⇕ఏ㐩⋡ࡢᩚ⌮ᘧ࡜ࡢẚ㍑ࢆ⾜ࡗࡓ㸬ᩚ⌮ᘧࢆ
ᅗ 5 ࡟♧ࡍ㸬ᅗ 5 ࡟♧ࡍࡼ࠺࡟㸪࢔ࣥࣔࢽ࢔ࡢἛ㦐⇕ఏ㐩ࡣᓊᕝࡢᩚ⌮ᘧ࡟ẚ࡭࡚ࡶ 1/4 ⛬ᗘࡢప࠸್ࢆ♧ࡍࡇ࡜ࡀศ࠿ࡿ㸬௨ୖࡢࡇ࡜ࡼࡾ㸪3 㔜⟶⇕஺᥮ჾࡣࣉ࣮ࣞࢺᘧ⵨Ⓨჾࡼࡾ࢔ࣥࣔࢽ࢔Ἓ㦐⇕ఏ㐩ࡢᛶ⬟ࡀపୗࡍࡿࡇ࡜ࡀ᫂ࡽ࠿࡟࡞ࡗࡓ㸬୍᪉࡛㸪⵨Ⓨჾධཱྀฟཱྀࡼࡾᚓࡽࢀࡓ⇕஺᥮ჾࡢ࢔ࣥࣔࢽ࢔ഃࡢᅽຊᦆኻࡣ 0.5 ~ 0.8kPa(Ỉ㢌᥮⟬࡛ 0.08~0.13m)࡛࠶ࡗࡓࡇ࡜࠿ࡽᅽຊᦆኻࡣ༑ศప࠸ࡇ࡜ࡀศ࠿ࡗࡓ㸬௒ᚋ㸪⇕㏻㐣⋡࡜࢔ࣥࣔࢽ࢔⇕3 重円筒型アンモニア蒸発器に関する研究ఏ㐩⋡ࡢపࡉࢆᨵၿࡍࡿࡓࡵ࡟㸪ᮏ᮶࣮࢝ࢺࣜࢵࢪᘧࢆ᝿ᐃࡋ࡚࠸ࡓෆ෇⟄㒊ࡢቑタࢆ⾜࠺ࡇ࡜࡛⇕஺᥮ჾ࠶ࡓ
ࡾࡢ⇕஺᥮㔞ࢆቑຍࡉࡏ㸪⇕஺᥮ჾᛶ⬟ࡢྥୖࢆ┠ᣦࡋࡓ◊✲ࢆ㐍ࡵ࡚⾜ࡃணᐃ࡛࠶ࡿ㸬2hWF [W/m ]hWF = 0.66qav
Present data
Correlation(Kishikawa, 2013)

104

103
104

105
qav [W/m ]2

Fig. 5 Heat flux vs. heat transfer coefficient for ammonia ⤖   ゝ
3 㔜෇⟶ᘧ⵨Ⓨჾࡢ࢔ࣥࣔࢽ࢔⇕㏻㐣⋡ ᐃ࡟࠾࠸࡚௨ୗࡢ⤖ᯝࡀᚓࡽࢀࡓ㸬(1) ␗࡞ࡿ᮲௳࡟࠾ࡅࡿ⇕㏻㐣⋡ࡢ ᐃࢆ⾜࠸㸪Wilson ἲ࡟ࡼࡾ Ỉὶ㏿࡜⇕㏻㐣⋡ࡢ㛵ಀࢆ᫂ࡽ࠿࡟ࡋࡓ㸬(2) ᖹᆒ⇕ὶ᮰࡜࢔ࣥࣔࢽ࢔⇕ఏ㐩⋡ࡢ㛵ಀࢆ᫂ࡽ࠿࡟ࡋ࡚㸪࠿ࡘ㐣ཤࡢ᥎⟬ᘧ࡜ࡢẚ㍑ࢆ⾜࠸㸪ࡑࢀࡽ࡜ẚ㍑
ࡋ࡚⇕ఏ㐩ᛶ⬟ࡀప࠸ࡇ࡜ࡀ᫂ࡽ࠿࡟࡞ࡗࡓ㸬ᩥ   ⊩(1) Kushibe M., Ikegami, Y., Monde, M., Uehara, H., “Evaporation heat transfer of ammonia and pressure drop of warm
water for plate type evaporator”, Transactions JSRAE, Vol. 22, No. 4 (2005), pp. 403-415 (in Japanese).
(2) Arima, A., Kim, J-H., Okamoto, A., Ikegami, Y., “Local boiling heat transfer characteristics of ammonia in a verticalplate evaporator”, International Journal of Refrigeration, Vol. 33, No. 2, (2010), pp. 359-370.
(3) Ikegami, Y., Hirao Y., Kumabe N., Sudoh G., Uehara H, “Study on ammonia refrigerator system using dry typeevaporator of plate type-heat exchanger”, 38th National Heat Transfer Symposium of Japan, (2001), pp. 501-502. (inJapanese)(4) Brown J., Pearson F. S., “Performance of propane, ammonia and carbon dioxide in long tube evaporators and plate heatexchangers”, IIR B1,B2, E1, E2, (1996), pp. 777-783.
(5) Zamfirescu C., Chiriac F., “Heat transfer measurements on ammonia forced convection boiling in vertical tubes”,
Experimental Thermal and Fluid Science, Vol. 25, (2002), pp. 529-534.
(6) P-Propath, http://www2.mech.nagasaki-u.ac.jp/cgi-bin/PROPATH/p-propath.cgi. (2006.4).
(7) Kishikawa, Y., “Study for OTEC system using ammonia or ammonia/water mixture as a working fluid”, Master thesisof Graduate school of Saga University, (2012), p. 141 (in Japanese).
(8) Wilson E. E., “A Basic for Rational Design of Heat Transfer Apparatus”, Transactions of ASME, Vol. 37, (1915), pp.
47-70.

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