Defroster and refrigerator having same

A defroster comprising:

• a heating unit including a heater case vertically arranged outside of an evaporator in an up-down direction of the evaporator, and a heater vertically arranged in the heater case in the up-down direction at least partially;
• and
• a heat pipe that is connected to each of an outlet provided at an upper side of the heating unit and an inlet provided at a lower side of the heating unit, that is arranged near a cooling pipe of the evaporator at least partially, and that is configured to guide a working fluid heated by the heater to transfer heat to the evaporator for removal of frost,
• wherein, in a state in which all of the working fluid inside the heat pipe is in a liquid state, the heater is configured to be positioned below a surface of the working fluid,
• wherein the heat pipe comprises a lowermost-row horizontal pipe that is arranged near a lowermost-row cooling pipe of the evaporator,
• wherein an upper end of the heating unit is positioned below a cooling pipe disposed directly above the lowermost-row cooling pipe of the evaporator,
• wherein the heater includes an active heating portion configured to emit heat to actively heat the working fluid, and
• wherein the inlet of the heating unit is positioned to correspond to the active heating portion.

A defroster comprising:

• a heating unit including a heater case vertically arranged outside of an evaporator in an up-down direction of the evaporator, and a heater vertically arranged in the heater case in the up-down direction at least partially;
• and
• a heat pipe that is connected to each of an outlet provided at an upper side of the heating unit and an inlet provided at a lower side of the heating unit, that is arranged near a cooling pipe of the evaporator at least partially, and that is configured to guide a working fluid heated by the heater to transfer heat to the evaporator for removal of frost,
• wherein the heat pipe includes:
• an evaporation part connected to the outlet of the heating unit, and arranged to correspond to the cooling pipe of the evaporator to transfer heat to the cooling pipe of the evaporator, and
• a condensation part extended from the evaporation part, arranged below a lowermost-row cooling pipe of the evaporator, and connected to the inlet of the heating unit,
• wherein the heater includes:
• an active heating portion configured to emit heat to actively heat the working fluid, and
• a passive heating portion provided below the active heating portion and heated to a lower temperature than the active heating portion, and
• wherein the inlet of the heating unit is positioned to correspond to the passive heating portion to allow the working fluid returning along the heat pipe to be introduced into the passive heating portion.