Heat engine

A heat engine, comprising:

• so a boiler unit which includes an evaporation chamber and a fluid-pool chamber, the evaporation chamber heating a working fluid by heat obtained from solar light and generating vapor, and the fluid-pool chamber collecting the working fluid supplied to the evaporation chamber;
• an output unit through which the vapor generated by the evaporation chamber flows, and which converts energy of the vapor to mechanical energy;
• a condensation unit which condenses the vapor that has passed through the output unit, and refluxes the condensed working fluid to the fluid-pool chamber;
• and
• a working fluid guide member which is disposed in the boiler unit, and which sucks the working fluid in the fluid-pool chamber by using capillary force and supplies the working fluid to the evaporation chamber, wherein
• the evaporation chamber is separated from the fluid-pool chamber, pressure in the evaporation chamber being higher than pressure in the fluid-pool chamber,
• the working fluid guide member is configured to satisfy the following expression:
• (2σ/r)·cos θ>PH−PL
• where σ is a surface tension of the working fluid, r is a circle-equivalent radius of a void in the working fluid guide member, θ is a wetting angle of the working fluid with respect to the working fluid guide member, PH is pressure in the evaporation chamber, and PL is pressure in the fluid-pool chamber,
• the boiler unit includes a solar light introducing portion which introduces the solar light into the evaporation chamber, and
• the working fluid guide member includes a heat-reception portion which receives the solar light introduced through the solar light introducing portion so as to be heated by the solar light.