초록 ▼

A fuel system for a marine engine has a recirculation cooler which receives a portion of fuel discharged from a fuel pump, cools that fuel, and then returns the cooled fuel to the inlet of the fuel pump to reduce fuel vapor formation and to cool the pump as the cooled fuel flows through the pump. Th

A fuel system for a marine engine has a recirculation cooler which receives a portion of fuel discharged from a fuel pump, cools that fuel, and then returns the cooled fuel to the inlet of the fuel pump to reduce fuel vapor formation and to cool the pump as the cooled fuel flows through the pump. The recirculation cooler is preferably formed of a material of high thermal conductivity and has a water passage adjacent to the fuel passage to reduce the temperature of the fuel that flows through the recirculation cooler. The recirculation cooler is preferably used in high heat applications or with a speed controlled fuel pump, with a pulse width modulated drive, for example. In these applications, during at least some fuel flow conditions, the flow of fuel through the fuel pump may be insufficient to cool the fuel pump motor and may cause increased fuel vapor formation. Desirably, the cooler fuel provided from the recirculation cooler to the inlet of the fuel pump supplements the cooling of the fuel pump motor and reduces fuel vapor formation.

대표청구항 ▼

1. A fuel system with a recirculation cooler for an internal combustion engine, comprising:an electric fuel pump having a fuel inlet and a fuel outlet for supplying fuel at a varying flow rate under high pressure to the engine; a cooler housing; a fuel passage defined at least in part in the hosing

1. A fuel system with a recirculation cooler for an internal combustion engine, comprising:an electric fuel pump having a fuel inlet and a fuel outlet for supplying fuel at a varying flow rate under high pressure to the engine; a cooler housing; a fuel passage defined at least in part in the hosing having a fuel inlet in communication with the outlet of the electric fuel pump, and a fuel outlet in communication with the fuel inlet of the electric fuel pump; a coolant passage defined at least in part in the housing separate from and generally adjacent to the fuel passage having a coolant inlet in communication with a source of coolant, and a coolant outlet from which coolant is discharged from the recirculation cooler; a drive controlling the electric fuel pump to vary the flow rate of fuel under high pressure delivered to the engine in response to the engine fuel demand and to circulate fuel through the cooler at least during engine low fuel demand conditions; whereby under at least engine low fuel demand conditions, a portion of the fuel discharged from the outlet of the electric fuel pump flows into the recirculation cooler through the fuel inlet thereof and is cooled before flowing out of the recirculation cooler housing through the fuel outlet to the inlet of the electric fuel pump to cool the electric fuel pump and reduce fuel vapor formation.