A method for cooling an engine includes increasing the pressure of a liquid coolant from a first pressure to a second pressure. Thereafter, components of the engine to be cooled are contacted with the liquid coolant so that the liquid coolant at least partially evaporates and forms a vapor with a particular state. Thereafter, the vapor is fed to a throttle to reduce the pressure of the liquid coolant to a third pressure. The particular state of the vapor is determined based on the temperature and the third pressure of the liquid coolant downstream of the throttle, and based on the second pressure of the liquid coolant under an assumption that the throttle is an adiabatic throttle such that enthalpy of the liquid coolant remains constant as the liquid coolant passes the throttle. A desired vapor state adjustment is made based on the determined particular state of the vapor.

A coolant pressure regulator system includes a coolant circuit, and a pressurized fluid circuit selectively fluidically connected to the coolant circuit. The pressurized fluid circuit includes a pump operably to selectively raising a pressure of coolant in the coolant circuit.

An apparatus for controlling the flow rate of engine coolant by use of a thermostat may include a thermostat arranged in an inflow flow path for the engine coolant and a flow rate regulator arranged in a bypass flow path for the engine coolant between a cylinder head of an engine and the thermostat. The flow rate regulator regulates the flow rate of the bypass flow path such that a differential pressure of the coolant between a front end for allowing the coolant flowing from a radiator to flow into the thermostat and a rear end for allowing the coolant to be discharged from the thermostat is within a predetermined range.

Methods and systems are provided for a coolant circuit. In one example, the coolant circuit comprises high and low-temperature radiators, where only one pump is configured to conduct coolant through the entire coolant circuit.

An engine-controlling device includes a coolant passage, a radiator, and a control valve. A coolant discharged from a pump circulates through the coolant passage. The radiator cools the coolant. The control valve includes a first valve that adjusts a flow rate of the coolant to be introduced into the radiator and that includes a valve member driven by an electric actuator, a second valve that is arranged in parallel with the first valve and that includes a valve member that is opened in accordance with a pressure or a temperature, and a malfunction-diagnosing unit that detects a valve-stuck malfunction of the first valve. An output of the engine is limited to an output equal to or less than a limiting value determined on a basis of a maximum flow rate of the coolant introduced into the radiator from the second valve when the valve-stuck malfunction of the first valve occurs.

The present invention relates to a cooling system valve (24) for an internal combustion engine cooling system (12), the internal combustion engine cooling system (12) comprising a radiator (14) and a coolant passage (16) adapted to cool at least a portion of an internal combustion engine (18), the cooling system valve (24) being adapted to be located between the radiator (14) and the coolant passage (16), as seen in an intended direction of flow from the radiator (14) to the coolant passage (16). The cooling system valve (24) is adapted to automatically assume each one of at least the following conditions: an open condition, allowing coolant transport from the radiator (14) towards the coolant passage (16) via the cooling system valve (24), and a closed condition, preventing coolant transport in a direction from the coolant passage (16) towards the radiator (14) via the cooling system valve (24).

An apparatus includes two pumps and a circuit-changing valve connected to two cooling circuits, with the valve being controlled by a pressure differential created by the pumps. This simplifies controls, reduces components of the pumping system, and also provides a backup pump for each system. The valve's spool is controlled so that when the first pump is started before the second pump (or it generates a higher fluid pressure), the valve causes the two pumps to be connected in a serial arrangement with fluid being pumped through the first circuit and then through the second circuit. But when the second pump is started before the first pump, the valve causes the two pumps to be connected in a parallel arrangement so that the first pump moves fluid only through the first circuit, and the second pump moves fluid only through the second circuit. The valve includes an anti-dithering device.

A method for coolant pump flow rationalization using coolant pump parameters includes calculating a first pump coolant flow based on a coolant input pressure sensor signal and the coolant pump speed. Further, the method includes calculating a second pump coolant flow based on coolant pump current and coolant pump speed when the first pump coolant flow is greater than a predetermined threshold; and comparing the first pump coolant flow with the second pump coolant flow to rationalize the coolant pressure sensor signal.

A coolant pressure regulator system includes a coolant circuit, and a pressurized fluid circuit selectively fluidically connected to the coolant circuit. The pressurized fluid circuit includes a pump operably to selectively raising a pressure of coolant in the coolant circuit.

A system includes an engine block having a plurality of cylinder-piston combinations. At least one of the cylinder-piston combinations includes a cylinder, a piston positioned in the cylinder and coupled to a connecting rod, the piston having an internal cooling gallery about a circumference of the piston, an oil jet for introducing coolant into the cooling gallery, and at least one pressure sensor positioned within the piston to detect pressure fluctuations within the cooling gallery. The system includes a processor having a program coupled thereto. The processor is configured to detect cyclical pressure fluctuations within the cooling gallery, via the at least one pressure sensor, during a linear motion of the piston within the engine block, determine pressures that occur during the detected cyclical pressure fluctuations, and determine a fill ratio of coolant within the cooling gallery based on the determined pressures.