| Title |
Effects of Pulsating Flow on Evaporation of Refrigerantin a Plate Heat Exchanger |
| Keywords |
Plate heat exchanger ; 판형 열교환기 ; Pulsating flow ; 맥동유동 ; Evaporation heat transfer enhancement ratio ; 증발열전달 향상비 |
| Abstract |
Evaporation heat transfer characteristics by pulsating flow in a plate heat exchanger have been investigated experimentally in this study. R-134a is evaporated by receiving heat from the hot water in the plate heat exchanger. The pulsating frequency in refrigerant side of the plate heat exchanger is varied in the range of 5∼25Hz. The operating pressure of R-134a and mass flux of hot water are also varied 0.6∼0.9MPa and 45∼105kg/㎡s, respectively. The experimental results indicate that evaporation heat transfer coefficient of pulsating flow is improved up to 6.3% compared with that of the steady flow at 10Hz and45 kg/㎡s. It is also found that the evaporation heat transfer enhancement ratio is decreased with an increase in mass flux of hot water, and the evaporation heat transfer enhancement is little influenced by operating pressure of R-134a. |