モントリオール議定書によりオゾン破壊能を持つ冷媒CFCやHCFCは全廃され、代替冷媒としてHFCが普及してきた．しかし，HFCはGWP(地球温暖化係数)が高いために，京都議定書により，排出量削減の対象となっている．そこで，次世代冷媒としてR32やR1234yfなどの従来に比べGWPが低い冷媒が注目されているが，これらの冷媒は微燃性を有するものが多く、また熱物性、伝熱性能など不明な点が多数残っている。 本学では、そのような冷媒の実機での利用に際しての基本熱物性、伝熱性能、リスク評価において必要となる知見を得ることを目的として、下記の研究を行う :

• 低GWP混合冷媒の熱物性測定

混合冷媒の気液平衡、粘性などの実験測定と状態方程式の作成

• 低GWP（混合）冷媒の伝熱性能評価

低GWP冷媒R1234yfおよびR32の蒸発、凝縮伝熱特性を把握し、低圧力損失・高伝熱性能の伝熱管形状を考案する

• 低GWP冷媒の安全性評価

微燃性冷媒の漏えいシミュレーション、低温室効果冷媒の熱分解生成物分析、微燃性冷媒、潤滑油、空気の混合ガスの圧縮による自己着火燃焼特性の把握

参考文献

Erguang Huo, Chao Liu, Xiaoxiao Xu, Qibin Li, Chaobin Dang, Dissociation mechanisms of HFO-1336mzz(Z) on Cu(1 1 1), Cu(1 1 0) and Cu(1 0 0) surfaces: A density functional theory study, Applied Surface Science, 443 (15) 389-400 (2018) [DOI: 10.1016/j.apsusc.2018.03.001]

Tomohiro HIGASHI, Shizuo SAITOH, Chaobin DANG, Eiji HIHARA," Diesel combustion of oil and refrigerant mixture during pump-down of air conditioners "，International Journal of Refrigeration, 75, 300-310 (2017) [doi: 10.1016/j.ijrefrig.2017.01.003];

東 朋寛・玉井 翔・斎藤静雄・党 超鋲・ 飛原英治，" エアコンポンプダウン時の圧縮機の爆発事故における潤滑油の影響 "，日本冷凍空調学会論文集, 34(3) 181-191(2017)

Chao LIU, Xiaoxiao XU, Chaobin DANG,Erguang HUO," A ReaxFF-based molecular dynamics study of the pyrolysis mechanism of HFO-1336mzz(Z)"，International Journal of Refrigeration, 83, 118-130 (2017) [doi.org/10.1016/j.ijrefrig.2017.07.009]

Makoto Ito, Chaobin Dang, Eiji Hihara, Thermal Decomposition of Lower-GWP Refrigerants, International Refrigeration and Air Conditioning Conference at Purdue, 14-17th, July, 2014, Purdue University, USA. (link)

Minxia Li, Chaobin Dangb,Eiji Hihara, "Flow boiling heat transfer of HFO1234yf and R32 refrigerant mixtures in a smooth horizontal tube: Part II. Prediction model" International Journal of Heat and Mass Transfer (2013) (accepted for publication)

Takumi Kamiaka, Chaobin Dang，Eiji Hihara, "Vapor-liquid equilibrium measurements for binary mixtures of R1234yf with R32, R125, and R134a" International Journal of Refrigeration 36 (3), 965-971 (2012)

Linlin Wang, Chaobin Dang, Eiji Hihara, "Experimental study on condensation heat transfer of low GWP refrigerant HFO1234yf in a horizontal tube" International Journal of Refrigeration 35, 1418-1429 (2012)

Minxia Li, Chaobin Dang, Eiji Hihara, "Flow boiling heat transfer of HFO1234yf and R32 refrigerant mixtures in a smooth horizontal tube: Part I. Experimental investigation" International Journal of Heat and Mass Transfer 55, 3437-3446 (2012)

Shizuo Saitoh, Chaobin Dang, Yoshitaka Nakamura, Eiji Hihara, "Boiling heat transfer of HFO-1234yf flowing in a smooth small-diameter horizontal tube," International Journal of Refrigeration 34, 1846-1853 (2011)

Minxia Li, Chaobin Dang, Eiji Hihara, Prediction of flow boiling heat transfer coefficient of binary mixture (HFO1234yf + R32) in a horizontal smooth tube, Proceedings of 3rd International forum on heat transfer, November 13-15, Nagasaki, Japan, paper No. IFHT2012-084.

Shizuo Saitoh, Chaobin Dang, Eiji Hihara, Effect of lubricating oil on flow boiling heat transfer of low GWP refrigerant HFO-1234yf in a horizontal small-diameter tube, Proceedings of 3rd International forum on heat transfer, November 13-15, Nagasaki, Japan, paper No. IFHT2012-111.

Linlin Wang, Chaobin Dang, Eiji Hihara, Experimental and theoretical study on condensation heat transfer of nonazeotropic refrigerant mixtures R1234yf/R32 inside a horizontal smooth tube, International Refrigeration and Air Conditioning Conference at Purdue, 16-19th, July, 2012, Purdue University, USA.

Minxia Li, Chaobin Dang, Eiji Hihara, Flow Boiling Heat Transfer of Binary Mixtures HFO1234yf/R32 in a Smooth Horizontal Tube, International Refrigeration and Air Conditioning Conference at Purdue, 16-19th, July, 2012, Purdue University, USA.

Minxia Li, Chaobin Dang, Eiji Hihara, Flow boiling heat transfer characteristics of refrigerant mixture HFO-1234yf/HFC-32 in a smooth horizontal tube, the 23rd IIR international Congress of Refrigeration, 21-26th, Aug., 2011, Prague, Czech Republic.

T. Kamiaka, Y. Arakawa, Chaobin Dang, Eiji Hihara, Vapor-liquid equilibria of binary refrigerant mixtures containing HFO-1234yf, the 23rd IIR international Congress of Refrigeration, 21-26th, Aug., 2011, Prague, Czech Republic.

Minxia Li, Chaobin Dang, Eiji Hihara, Experimental investigation of flow boiling heat transfer of the HFC32 and HFO1234yf refrigerant mixture in a smooth horizontal tube, 10th IEA Heat Pump Conference 2011, 16th-19th, May., 2011, Tokyo, Japan.

S. Saitoh, C. Tanaka, K. Hoshika, Chaobin Dang, Eiji Hihara, Flow boiling heat transfer and pressure drop for pure refrigerant R-290 and R-290/Oil mixture in horizontal small-diameter tubes, The 5th Asian Conference on Refrigeration and Air-conditioning, 7th-9th, June, 2010, Tokyo, Japan.

Hayato Horie, Chaobin Dang, Eiji Hihara, Life cycle climate performance of air conditioner, The 5th Asian Conference on Refrigeration and Air-conditioning,, 7th-9th, June, 2010, Tokyo, Japan.

H. Horie, Chaobin Dang, Eiji Hihara, Annual performance and performance rating of air conditioner, The 5th Asian Conference on Refrigeration and Air-conditioning,, 7th-9th, June, 2010, Tokyo, Japan.

Hayato Horie, T. Kamiaka Chaobin Dang, Eiji Hihara, Study ON Cycle Property and LCCP Evaluation of Heat Pump Using HFO-1234yf, HFC-32, and HFC-410A as Refrigerant, 2010 International Symposium on NEXT-generation Air Conditioning and Refrigeration Technology, 17th-19th, Feb., 2010, Tokyo, Japan.

Y. Arakawa, H.S. Kim, T. Kamiaka, Chaobin Dang, Eiji Hihara, Thermophysical Property Measurement of HFO-1234yf + HFC-32 Mixtures, 2010 International Symposium on NEXT-generation Air Conditioning and Refrigeration Technology, 17th-19th, Feb., 2010, Tokyo, Japan.