日本語フィールド
著者：堀井 克則, 仮屋 圭史, 宮崎 祐輔, 中嶋 祐紀, 森 英夫 読み: ホリイカツノリ，カリヤケイシ，ミヤザキユウスケ，ナカシマユウキ，モリヒデオ題名：蒸発器管内冷媒の流動特性と熱輸送を考慮した冷蔵庫除霜運転の効率向上に関する研究(第2報)単列モデルによる除霜評価発表情報：日本冷凍空調学会論文集 巻: 30 号: 4 ページ: 377-387キーワード：Refrigerator, Defrost, Evaporator, Refrigerant, Flow Pattern, heat transfer, Frost melting概要：前報と同じ単列モデルを用いて，着霜状態での除霜実験を行い，整理した無着霜状態での加熱実験結果と比較して除霜時の冷媒流動を検討した．基本的には，下段で蒸発した冷媒蒸気が上段に冷媒液を押し上げながら上昇し，上段で冷媒蒸気が凝縮する様相であるが，霜の融解が終了した下段では，上段からの液の下降が滞り，下段から順次過熱蒸気単相状態に至ると推測した．また，管内に冷媒を充てんしない真空条件での除霜実験を行い，上昇した冷媒蒸気が上段で凝縮して凝縮潜熱を放出する，すなわち冷媒の熱輸送が霜の融解に寄与しており，ヒータから離れた上段の霜の融解に有効であり，除霜終了を早めていることが分かった．抄録：前報と同じ単列モデルを用いて，着霜状態での除霜実験を行い，整理した無着霜状態での加熱実験結果と比較して除霜時の冷媒流動を検討した．基本的には，下段で蒸発した冷媒蒸気が上段に冷媒液を押し上げながら上昇し，上段で冷媒蒸気が凝縮する様相であるが，霜の融解が終了した下段では，上段からの液の下降が滞り，下段から順次過熱蒸気単相状態に至ると推測した．また，管内に冷媒を充てんしない真空条件での除霜実験を行い，上昇した冷媒蒸気が上段で凝縮して凝縮潜熱を放出する，すなわち冷媒の熱輸送が霜の融解に寄与しており，ヒータから離れた上段の霜の融解に有効であり，除霜終了を早めていることが分かった．英語フィールド
Author：Katsunori HORII, Keishi KARIYA, Yusuke MIYAZAKI, Yuki NAKASHIMA, Hideo MORITitle：Study on Performance Improvement of Defrosting for Refrigerator Considering Characteristics of Refrigerant Flow and Heat Transfer inside Evaporator Tube(2nd Report)Evaluation during Defrosting Process using Single-Row ModelAnnouncement information:Transactions of the Japan Society of Refrigerating and Air Conditioning Engineers Vol: 30 Issue: 4 Page: 377-387Keyword：Refrigerator, Defrost, Evaporator, Refrigerant, Flow Pattern, heat transfer, Frost meltingAn abstract：This study is focused on refrigerant flow characteristics and heat transfer inside the evaporator tube to improve performance of defrosting for refrigerator. In the first report, evaluation of refrigerant vapor-liquid two-phase flow using the test section of single-row model simulating the refrigerator evaporator was carried out under heating condition, fundamental flow characteristics was clarified. In this report, evaluation of refrigerant flow and heat transfer using the same test section of single-row aluminum fin-tube model with frost carried out under defrosting condition. During defrosting, basically generated refrigerant gas went up to upper part of the test section while lifting liquid, and condensed by frost melting at upper part. However, in lower part which frost melting ended, liquid returning from upper part was overdue. As time passed dryout came out from lower to upper of the test section in sequence. Moreover, refrigerant gas condensing at upper part, that is, heat transport with refrigerant flow was effective in frost melting of upper part which was far from heater, and made defrosting finish early.An abstract：This study is focused on refrigerant flow characteristics and heat transfer inside the evaporator tube to improve performance of defrosting for refrigerator. In the first report, evaluation of refrigerant vapor-liquid two-phase flow using the test section of single-row model simulating the refrigerator evaporator was carried out under heating condition, fundamental flow characteristics was clarified. In this report, evaluation of refrigerant flow and heat transfer using the same test section of single-row aluminum fin-tube model with frost carried out under defrosting condition. During defrosting, basically generated refrigerant gas went up to upper part of the test section while lifting liquid, and condensed by frost melting at upper part. However, in lower part which frost melting ended, liquid returning from upper part was overdue. As time passed dryout came out from lower to upper of the test section in sequence. Moreover, refrigerant gas condensing at upper part, that is, heat transport with refrigerant flow was effective in frost melting of upper part which was far from heater, and made defrosting finish early.