| Title |
A Study on Evaporation Heat Transfer Characteristics of Heating Tubes for Falling Film Type Evaporator of Absorption Chiller or Adsorption Chiller |
| Authors |
Seong Min Kim ; Jae In Kim ; Sung Min Woo ; Min Soo Kim ; Chan Woo Park |
| DOI |
http://dx.doi.org/10.6110/KJACR.2018.30.11.508 |
| Keywords |
유하액막식 ; 증발기 ; 전열관 ; 흡수식 냉동기 Falling film ; Evaporator ; Heating tube ; Absorption chiller |
| Abstract |
In order to make the absorption refrigerator compact, 8 types (End cross 40, End cross 38, End cross 26, End cross 26-2 v, End dimple, Dimple corrugate, End cross 26) of high efficiency evaporation tube of falling film type evaporator were tested. The overall heat transfer coefficients were investigated with respect to the refrigerant liquid flow rate, working pressure, and the chilled water flow rate of the heat transfer tube. The optimum operating liquid film flow rate was determined for each tube. Appropriate liquid film flow rate exists depending on the shape of the heat transfer tube, and most suitable liquid coolant film Reynolds number (Film Reynolds, Ref) is between 20 and 50. The best performance tube was found to be End cross 40 tube. The heat transfer coefficient was 3.791 kW/m2K with a corresponding Reynolds number of 20 at a normal evaporator operating pressure of 0.866 kPa. |