5.5 Typical Technologies
175
Fig. 5.12 Shape of a VCHP
operation. When instruments stopped work during hibernation in lunar night, the
temperature of instruments and fluid in heat pipe gradually decreased with external
heat flow decreasing. When the temperature was lower than the freezing point, the
fluid was frozen and stopped flowing. The heat pipe no longer transferred heat
from instruments to heat dissipating surface in phase change to maintain instrument
temperature for storage requirement in lunar night. When the fluid was selected for
special heat pipe, freezing point and temperature range should meet requirements at
first. Besides, compatibility between fluid and material of heat pipe shell should be
verified as well as heat transfer characteristics.
175
Fig. 5.12 Shape of a VCHP
operation. When instruments stopped work during hibernation in lunar night, the
temperature of instruments and fluid in heat pipe gradually decreased with external
heat flow decreasing. When the temperature was lower than the freezing point, the
fluid was frozen and stopped flowing. The heat pipe no longer transferred heat
from instruments to heat dissipating surface in phase change to maintain instrument
temperature for storage requirement in lunar night. When the fluid was selected for
special heat pipe, freezing point and temperature range should meet requirements at
first. Besides, compatibility between fluid and material of heat pipe shell should be
verified as well as heat transfer characteristics.