Liquified light hydrocarbon fuel system for a hybrid electric vehicle

A fuel system for a hybrid vehicle, comprising:

• a) a fuel tank having a buffer space configured to provide room for a vaporized fuel;
• b) insulation, wherein the insulation is disposed around the fuel tank;
• c) a first fuel line having a first end and a second end, wherein the first end of the first fuel line extends into the buffer space of the fuel tank;
• d) a buffer tank wherein an inlet to the buffer tank is connected to the second end of the first fuel line;
• e) a pressure sensor measuring pressure in the fuel tank and sending digital or analog signals corresponding to pressure to a digital control unit through a signal bus, wherein the pressure sensor is connected to the fuel tank;
• f) a second fuel line having a first end and a second end, wherein the first end of the second fuel line connects to an outlet of the buffer tank;
• g) a solenoid valve, wherein an inlet of the solenoid valve connects to the second end of the second fuel line;
• h) a pressure regulator connected to an outlet of the solenoid valve wherein the pressure regulator is adapted to connect to a fuel inlet of an energy conversion device of the hybrid vehicle, wherein the energy conversion device is selected from the group consisting of internal combustion engines, fuel cells and Stirling engines, whereby the pressure regulator is configured to regulate the flow of vaporized fuel into the energy conversion device;
• i) a tank heating system, comprising:
• i. a chamber disposed between an outer surface of the fuel tank and the insulation, wherein the chamber is filled with a heat transfer fluid;
• ii. a first heat transfer line having a first end and a second end, wherein the first end of the first heat transfer line connects to an outlet of the chamber;
• iii. a butterfly valve, wherein the second end of the first heat transfer line connects to an inlet of the butterfly valve;
• iv. a heat transfer coil having a first end and a second end, wherein the heat transfer coil is disposed within a heat exchanger and wherein an outlet of the butterfly valve connects to an inlet of the heat transfer coil and an outlet of the heat transfer coil connects to an inlet of the chamber.