Methods and systems are provided for controlling coolant flow through parallel branches of a coolant circuit including an AC condenser and a charge air cooler. Flow is apportioned responsive to an AC head pressure and a CAC temperature to reduce parasitic losses and improve fuel economy. The flow is apportioned via adjustments to a coolant pump output and a proportioning valve.

Methods and systems are provided for controlling coolant flow through parallel branches of a coolant circuit including an AC condenser and a charge air cooler. Flow is apportioned responsive to an AC head pressure and a CAC temperature to reduce parasitic losses and improve fuel economy. The flow is apportioned via adjustments to a coolant pump output and a proportioning valve.

The invention provides a single radiator cooling system for use in hybrid electric vehicles, the system comprising a surface in thermal communication with electronics, and subcooled boiling fluid contacting the surface. The invention also provides a single radiator method for simultaneously cooling electronics and an internal combustion engine in a hybrid electric vehicle, the method comprising separating a coolant fluid into a first portion and a second portion; directing the first portion to the electronics and the second portion to the internal combustion engine for a time sufficient to maintain the temperature of the electronics at or below 175 C.; combining the first and second portion to reestablish the coolant fluid; and treating the reestablished coolant fluid to the single radiator for a time sufficient to decrease the temperature of the reestablished coolant fluid to the temperature it had before separation.

Provided is a compact boiling cooling system for an internal combustion engine that can operate in a stable manner. A lower end (4c) of a water jacket (4) of an engine (1) is connected to a lower tank (7c) of a radiator (7), and an upper end (4d) of a water jacket is connected to an upper part (7a) of the radiator. A substantially entire part of the radiator is located above the upper end of the coolant jacket so that the boiling cooling water is forwarded from the upper end of the water jacket to the upper part of the radiator, and the cooling water condensed in the radiator is forwarded from the lower end of the radiator to the lower end of the water jacket under the gravitational force without requiring a pump.

A system for rapidly heating a vehicle engine when the engine is below a pre-determined temperature allows for improved fuel efficiency after a vehicle cold-start. The system includes an organic Rankine cycle (ORC) loop having a two-phase ORC fluid traveling circuitously through a conduit. The ORC fluid is vaporized by a power electronics cooling device and by an evaporator in thermal communication with exhaust waste heat. The vaporized ORC fluid is passed through an expander to generate electrical power. When the vehicle engine is below the pre-determined temperature, heat from the vaporized ORC fluid is transferred directly or indirectly to the engine. When the vehicle engine is at or above the pre-determined temperature, heat from the vaporized ORC fluid is instead transferred to an alternate heat sink.

An ebullient cooling device includes: an internal combustion engine cooled by boiling a coolant flowing through a coolant passage formed within the internal combustion engine; a gas-liquid separator that separates a coolant discharged from the internal combustion engine into a liquid-phase coolant and a gas-phase coolant; a condenser that is disposed on a downstream side of the expander, and cools the gas-phase coolant having passed through the expander so as to be changed into a liquid-phase coolant; a first passage that supplies the liquid-phase coolant from the condenser to the coolant passage formed within the internal combustion engine; a second passage that is branched from the first passage, and is connected to the gas-liquid separator; and a control valve that controls a supply state of a liquid-phase coolant supplied to the gas-liquid separator from the condenser through the second passage.