Thermal transpiration flow heat pump

A thermal transpiration flow heat pump, comprising:

• an evaporator;
• a condenser;
• a medium flow path for circulating to the evaporator a medium, which has been condensed by the condenser to a liquid phase;
• and
• a medium transport unit that is provided between the evaporator and the condenser, wherein:
• the medium transport unit comprises:
• a medium-temperature heat source portion that is placed on a side of the evaporator and comprises a medium-temperature heat source flow path through which a medium-temperature heat source flow flows;
• a high-temperature heat source portion that is placed on a side of the condenser and comprises a high-temperature heat source flow path through which a high-temperature heat source flow flows;
• and
• a thermal transpiration flow pump that (i) is placed between the medium-temperature heat source portion and the high-temperature heat source portion, (ii) has a pore size of less than or equal to 10 times a mean free path of the medium at a saturated vapor pressure, and (iii) generates a thermal transpiration flow of the medium from the side of the evaporator to the side of the condenser by a temperature difference between a medium temperature of the medium-temperature heat source flow on the side of the evaporator and a high temperature of the high-temperature heat source flow on the side of the condenser;
• the evaporator (i) stores the medium circulated through the medium flow path in the liquid phase and (ii) causes, when an internal pressure of the evaporator is reduced by the medium transport unit, the medium in the liquid phase to be vaporized to a gas phase whose saturated vapor pressure equals the reduced internal pressure;
• and
• the condenser (i) causes, when an internal pressure of the condenser is increased by the medium transport unit, the medium in the gas phase transported from the side of the evaporator to be condensed to the liquid phase at a saturated vapor pressure equal to the increased internal pressure and (ii) stores the medium condensed to the liquid phase.