SYSTEMS FOR DELIVERING LIQUIFIED NATURAL GAS TO AN ENGINE

摘要

A fuel delivery system includes a fuel tank (14) configured to receive liquid natural gas. A first conduit (36) extends from a vapor holding portion (24) of the fuel tank (14) to an economizer valve (38). A second conduit (48) extends from a liquid holding portion (20) of the fuel tank (14) to the economizer valve (38). Fluid coupled to the economizer valve is a vaporizer (100) which is heated by coolant from the engine (30) and is positioned below the fuel tank (14). The economizer valve (38) selectively withdraws either liquid natural gas or vaporized natural gas from the fuel tank (14) depending on the pressure within the vapor holding portion (24) of the tank (14). A delivery conduit (114) extends from the vaporizer (100) to the engine (30). A return conduit (116) having a check valve (118) formed therein extends from the delivery conduit (114) to the vapor holding portion (24) of the fuel tank (14) for pressurizing the fuel tank (14).