External combustion engine

Abstract

An external combustion engine suppressing boiling of cooling water in a cooler. A heater 12 uses waste heat of a heat engine 1 as a heat source to heat a working medium to make it evaporate. A cooler 13 uses cooling fluid cooling the heat engine 1 as a cooling source to cool steam of the working medium and make it condense. A heated part temperature reducing means is provided for reducing a temperature Th of the heated part 12 a when the amount of heat radiated from the cooling fluid to the outside becomes smaller than the amount of heat transferred from the working medium to the cooling fluid. Due to this, it is possible to suppress the rise of the temperature Tw of the cooling fluid in the cooler 13, so it is possible to suppress boiling of the cooling water in the cooler 13.

1 . An external combustion engine provided with
 a pipe-shaped container in which a working medium is sealed flowably in a liquid state,   a heater having a heated part communicating with one end of the container and heating the working medium at the heated part to make it evaporate,   a cooler arranged at a middle of the container and cooling the steam of the working medium produced by the heater to make it condense, and   an output part communicated with the other end of the container and converting the displacement of the liquid part of the working medium produced due to the change in volume of the working medium accompanying evaporation and condensation of the working medium to mechanical energy for output,   the heater being designed to use waste heat of a heat engine as a heat source to heat the working medium and make it evaporate,   the cooler being designed to use a cooling fluid cooling the heat engine as a cooling source to cool the steam of the working medium and make it condense, and   the engine provided with a heated part temperature reducing means for reducing the temperature of the heated part when the amount of heat radiated from the cooling fluid to the outside becomes smaller than the amount of heat transferred from the working medium to the cooling fluid.   
   
   
       2 . An external combustion engine as set forth in  claim 1 , wherein said heated part temperature reducing means has a pump means for circulating the cooling fluid to the cooler. 
   
   
       3 . An external combustion engine as set forth in  claim 2 , wherein said heated part temperature reducing means controls the pump means based on at least one of the amount of waste heat of the heat engine, the temperature of the heated part, and the temperature of the cooling fluid. 
   
   
       4 . An external combustion engine as set forth in  claim 2 , wherein said pump means is driven by electric power. 
   
   
       5 . An external combustion engine as set forth in  claim 2 , wherein said pump means is coupled with an output part so as to be driven by output from the output part. 
   
   
       6 . An external combustion engine as set forth in  claim 2 , wherein the length of the flow path of the cooling fluid becomes shorter by providing a bypass flow path for circulating the cooling fluid bypassing the heat engine, and
 the bypass flow path is provided with a pump means and a radiating means for radiating the heat of the cooling fluid to the outside.   
   
   
       7 . An external combustion engine as set forth in  claim 6 , wherein said radiating means is provided with a heat storing material for storing the heat discharged from the cooling fluid. 
   
   
       8 . An external combustion engine as set forth in  claim 1 , wherein said heated part temperature reducing means has cooling means for cooling the heater from the outside. 
   
   
       9 . An external combustion engine as set forth in  claim 8 , wherein said cooling means is a means for blowing air to the heater. 
   
   
       10 . An external combustion engine as set forth in  claim 8 , wherein said cooling means is a means for spraying water to the heater. 
   
   
       11 . An external combustion engine as set forth in  claim 1 , wherein said heated part temperature reducing means has judging means for judging when the amount of heat radiated from the cooling fluid to the outside becomes smaller than the amount of heat transferred from the working medium to the cooling fluid based on at least the temperature of the heated part. 
   
   
       12 . An external combustion engine as set forth in  claim 11 , wherein said judging means deems that the amount of heat radiated from the cooling fluid to the outside has become smaller than the amount of heat transferred from the working medium to the cooling fluid when the heat engine has stopped and the temperature of the heated part exceeds the boiling point of the cooling fluid. 
   
   
       13 . An external combustion engine as set forth in  claim 11 , wherein said judging means calculates the temperature of the heated part based on the pressure inside the heated part. 
   
   
       14 . An external combustion engine as set forth in  claim 11 , wherein said judging means calculates the temperature of the heated part based on the radiant heat radiated from the heater.