Fuel heating apparatus for engines using heavy oil as fuel

A fuel heating apparatus for engines using a heavy oil as a fuel, comprising a heavy oil-holding fuel tank, a fuel injection pump to which said heavy oil is supplied from said fuel tank through a fuel passage, fuel injection nozzles adapted to inject said heavy oil into combustion chambers by an operation of said fuel injection pump, an exhaust gas passage through which an exhaust gas, which is generated when said heavy oil is ignited and burnt in said combustion chambers, is discharged, a first heating unit which is provided in the vicinity of a fuel outlet region of said fuel tank connected to said fuel passage, and which is adapted to heat said heavy oil by utilizing said exhaust gas, and a second heating unit which is provided in said fuel passage connected to said fuel injection pump, and which is adapted to heat said heavy oil by utilizing said exhaust gas,

• wherein said first heating unit comprises a member of a porous ceramic material provided in a bottom portion of said fuel tank and formed so that said heavy oil passes therethrough, an exhaust pipe provided in said porous ceramic member and forming a wall for separating passages for said exhaust gas and said heavy oil from each other, which exhaust pipe is joined at one end thereof to said exhaust pipe and opened at the other end thereof to the atmospheric air, a fuel pipe provided with communication ports from which said heavy oil passed through said passage formed of a porous ceramic member is discharged into said fuel passage, and a first heater provided in said fuel pipe.