A fuel supply system includes a sub fuel tank, a booster pump, a fuel pipe, a fuel pressure sensor and a controller. The sub fuel tank stores a fuel supplied thereto from a main fuel tank. The booster pump is disposed inside the sub fuel tank. The fuel pipe has a returnless structure and supplies the fuel with a pressure increased by the booster pump to a fuel injection device of an engine. The fuel pressure sensor detects the pressure of the fuel inside the fuel pipe. The controller is configured or programmed to perform a feedback control of the booster pump based on a value of the pressure of the fuel detected by the fuel pressure sensor such that the pressure of the fuel inside the fuel pipe becomes greater than or equal to a first threshold.

A pump arrangement for providing a saturated or subcooled liquid includes a tank for saturated liquid, a heat exchanger for cooling the saturated liquid, a pump, an expansion valve, and an output for feeding saturated or subcooled liquid to a consumer. A tank outlet is in fluid communication with a liquid inlet of the heat exchanger, such that saturated liquid stored inside the tank can flow into the heat exchanger designed to sub-cool the saturated liquid. A liquid outlet of the heat exchanger is in fluid communication with a pump inlet. The expansion valve outlet is in fluid communication with a coolant inlet of the heat exchanger. An expansion valve inlet is arranged for receiving and expanding a fraction of liquid flowing through the pump arrangement and routing it into the coolant input to at least partially evaporate and receive evaporation enthalpy of the liquid to be subcooled.

A pump arrangement for providing a saturated or subcooled liquid includes a tank for saturated liquid, a heat exchanger for cooling the saturated liquid, a pump, an expansion valve, and an output for feeding saturated or subcooled liquid to a consumer. A tank outlet is in fluid communication with a liquid inlet of the heat exchanger, such that saturated liquid stored inside the tank can flow into the heat exchanger designed to sub-cool the saturated liquid. A liquid outlet of the heat exchanger is in fluid communication with a pump inlet. The expansion valve outlet is in fluid communication with a coolant inlet of the heat exchanger. An expansion valve inlet is arranged for receiving and expanding a fraction of liquid flowing through the pump arrangement and routing it into the coolant input to at least partially evaporate and receive evaporation enthalpy of the liquid to be subcooled.