Heat pipe, exhaust heat recoverer provided therewith

Abstract

A heat pipe 23 has seven heating unit side heat pipe portions 23 a on the side of a heating unit 21 for heating pure water using heat of exhaust gas discharged from an engine, six evaporation unit side heat pipe portions 23 b on the side of an evaporation unit 22 for evaporating the pure water heated by each heating unit side heat pipe portion 23 a using heat of exhaust gas, and flow rate retardation means 4 for retarding the flow rate of the pure water flowing in the evaporation unit side heat pipe portions. The flow rate retardation means 4 is provided with a merging portion 23 c that merges the pure water heated by each heating unit side heat pipe portion, on the evaporation unit side, and whose a flow path cross-sectional area is set to be larger than that of each heating unit side heat pipe portion 23 a.

1 .- 2 . (canceled) 
     
     
         3 . The heat pipe according to  claim 12 , wherein a flow path cross-sectional area orthogonal to the vertical direction of the merging portion is larger than a flow path cross-sectional area orthogonal to the vertical direction of the plurality of heating unit side heat pipe portions. 
     
     
         4 . The heat pipe according to  claim 12 , wherein a flow path cross-sectional area orthogonal to the vertical direction of the merging portion is larger than a flow path cross-sectional area orthogonal to the vertical direction of the evaporation unit side heat pipe portion. 
     
     
         5 . The heat pipe according to  claim 12 , further comprising throttling portion which is provided between the merging portion and the evaporation unit side heat pipe portion and which restricts the flow path cross-sectional area orthogonal to the vertical direction. 
     
     
         6 . The heat pipe according to  claim 12 , wherein the merging portion is provided near the center of an exhaust pipe through which the exhaust gas flows. 
     
     
         7 . The heat pipe according to  claim 12 , wherein the cross-section of the merging portion orthogonal to the direction of flow of the exhaust gas is in the shape of a semi-circular arc. 
     
     
         8 . The heat pipe according to  claim 12 , wherein the working fluid further heated by the evaporation unit is a vapor phase working fluid. 
     
     
         9 . The heat pipe according to  claim 12 , wherein the evaporation unit is arranged higher than the heating unit in the vertical direction. 
     
     
         10 . An exhaust heat recoverer comprising:
 the heat pipe according to  claim 12 ; and   a condensation unit into which is introduced the working fluid further heated by the evaporation unit and in which the introduced working fluid is cooled.   
     
     
         11 . (canceled) 
     
     
         12 . A heat pipe comprising;
 a heating unit that is provided with a heating unit side heat pipe portion that heats a working fluid using heat of exhaust gas discharged from an engine;   an evaporation unit that is provided with an evaporation unit side heat pipe portion through which the working fluid flows, and that further heats the working fluid heated by the heating unit side heat pipe portion using heat of the exhaust gas; and   flow rate retardation unit that retards the flow rate of the working fluid flowing into the evaporation unit side heat pipe portion,   wherein:   the heating unit side heat pipe portion is provided in plurality; and   the flow rate retardation unit is provided with a merging portion that merges the working fluid respectively heated by the plurality of heating unit side heat pipe portions, on the evaporation unit side.   
     
     
         13 . The heat pipe according to  claim 12 , wherein:
 the flow rate retardation unit is arranged to be connected to both one end of the evaporation unit side heat pipe portion and one end of the heating unit side heat pipe portion;   the one end of the evaporation unit side heat pipe portion is an end on the side of the heating unit; and   the one end of the heating unit side heat pipe portion is an end on the side of the evaporation unit.