TY - JOUR
T1 - Effects of flash gas generation at the expansion device inlet on the dynamic characteristics of a refrigeration system
AU - Kang, Hoon
AU - Joo, Youngju
AU - Kim, Yong Chan
PY - 2008/5/1
Y1 - 2008/5/1
N2 - The flash gas generation at the expansion device inlet in multi-air-conditioners causes rapid reduction of refrigerant mass flow rate and irregular distribution of refrigerant into multi-indoor units. The objective of this study is to evaluate the influence of the flash gas generation on the dynamic characteristics of a refrigeration system. The dynamic characteristics of a refrigeration system with an electronic expansion valve (EEV) were measured with time at various levels of flash gas generation, which were expressed as flash gas ratio. In addition, the averaged operating parameters and system COP were investigated with the variation of flash gas ratio. As the EEV inlet condition changed from the subcooled to the two-phase state, the refrigerant flow rate decreased rapidly due to the flash gas generation at the EEV inlet. At two-phase inlet conditions, the system operating parameters, such as mass flow rate, suction and discharge pressures, fluctuated periodically with time. As the flash gas ratio increased, the average COP decreased and the discharge temperature increased, degrading the system performance and reliability more severely.
AB - The flash gas generation at the expansion device inlet in multi-air-conditioners causes rapid reduction of refrigerant mass flow rate and irregular distribution of refrigerant into multi-indoor units. The objective of this study is to evaluate the influence of the flash gas generation on the dynamic characteristics of a refrigeration system. The dynamic characteristics of a refrigeration system with an electronic expansion valve (EEV) were measured with time at various levels of flash gas generation, which were expressed as flash gas ratio. In addition, the averaged operating parameters and system COP were investigated with the variation of flash gas ratio. As the EEV inlet condition changed from the subcooled to the two-phase state, the refrigerant flow rate decreased rapidly due to the flash gas generation at the EEV inlet. At two-phase inlet conditions, the system operating parameters, such as mass flow rate, suction and discharge pressures, fluctuated periodically with time. As the flash gas ratio increased, the average COP decreased and the discharge temperature increased, degrading the system performance and reliability more severely.
KW - Electronic expansion device
KW - Expansion
KW - Gas
KW - Parameter
KW - Performance
KW - Refrigeration system
KW - Survey
KW - Two-phase flow
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U2 - 10.1016/j.ijrefrig.2007.08.005
DO - 10.1016/j.ijrefrig.2007.08.005
M3 - Article
AN - SCOPUS:40049098656
VL - 31
SP - 396
EP - 403
JO - International Journal of Refrigeration
JF - International Journal of Refrigeration
SN - 0140-7007
IS - 3
ER -