A vehicle propulsion system includes a prime mover having a coolant inlet and a coolant outlet, a coolant control valve having a valve inlet in communication with the prime mover coolant outlet, a first valve outlet, and a second valve outlet, a bypass flow path in communication with first valve outlet and the prime mover coolant inlet, a heat exchange flow path in communication with the second valve outlet and the prime mover inlet, a heat exchanger in the heat exchange flow path, a first temperature sensor in the bypass flow path for generating a first temperature signal, a second temperature sensor in the heat exchange flow path for generating a second temperature signal, and a controller for providing a coolant control valve command signal to the coolant control valve, using a normalized gain coefficient.

A temperature sensor for a first fluid senses a temperature of the first fluid downstream of a heat exchanger. A supply for a second fluid changes a temperature of the first fluid. The supply for the second fluid passes through the heat exchanger. A valve is positioned upstream of the said heat exchanger on the supply for the second fluid, and controls a flow rate of the second fluid diverted into a bypass line compared to a flow rate of the second fluid directed through the heat exchanger, with the three-way valve controlled by a control in response to feedback from said temperature sensor. The valve changes the respective flow rates delivered into the bypass line and through the said heat exchanger in a non-linear manner with a change in valve position. A manned spaceship is also disclosed.

A cooling system selectively cools an engine and an exhaust gas recirculation (EGR) component of the engine. The cooling system includes a plumbing system with a plurality of flow branches, including an engine branch, an EGR branch, and a feed branch. The engine branch defines an engine flow passage through which the coolant flows to cool the engine. The EGR branch defines an EGR flow passage through which the coolant flows to cool the EGR component. The feed branch defines a feed flow passage. The cooling system has a first operating configuration in which the EGR flow passage is configured to receive coolant flow from the engine flow passage. The cooling system has a second operating configuration in which the EGR flow passage is configured to receive coolant flow from the feed flow passage instead of the engine flow passage.

Examples of techniques for controlling temperature of a coolant fluid at an inlet of an internal combustion engine are disclosed. In one example implementation, a method includes receiving, by a processing device, total fuel burned data indicating a total amount of fuel burned by the internal combustion engine. The method further includes receiving, by a processing device, engine speed data indicating an engine speed of the internal combustion engine. The method further includes calculating, by the processing device, a radiator flow rate to achieve a temperature set-point at an inlet of the engine based at least in part on the total fuel burned data and the engine speed data. The method further includes adjusting, by the processing device, a radiator flow based at least in part on the radiator flow rate.

An engine cooling system includes a coolant circulation path, which circulates coolant between the water jacket and the radiator of an internal combustion engine, a pump, a control valve, which is provided in the coolant circulation path, and a controller. The controller executes a warming-up promotion control and a pressure relaxation control. In the pressure relaxation control, the controller controls the aperture ratio of the radiator port such that the lower the temperature of the radiator, the lower becomes the engine rotational speed at which the aperture ratio of the radiator port is increased.

A cooling system selectively cools an engine and an exhaust gas recirculation (EGR) component of the engine. The cooling system includes a plumbing system with a plurality of flow branches, including an engine branch, an EGR branch, and a feed branch. The engine branch defines an engine flow passage through which the coolant flows to cool the engine. The EGR branch defines an EGR flow passage through which the coolant flows to cool the EGR component. The feed branch defines a feed flow passage. The cooling system has a first operating configuration in which the EGR flow passage is configured to receive coolant flow from the engine flow passage. The cooling system has a second operating configuration in which the EGR flow passage is configured to receive coolant flow from the feed flow passage instead of the engine flow passage.

A coolant control system of a vehicle includes an adjusting module that: (i) receives an engine output coolant temperature measured at a coolant output of an internal combustion engine; (ii) adjusts the engine output coolant temperature based on a reference temperature to produce a first adjusted coolant temperature; (iii) receives an engine input coolant temperature measured at a coolant input of the internal combustion engine; and (iv) adjusts the engine input coolant temperature based on the reference temperature to produce a second adjusted coolant temperature. The coolant control system also includes a difference module that determines a difference between the first and second adjusted coolant temperatures. The coolant control system also includes a pump control module that controls a coolant output of a coolant pump based on the difference between the first and second adjusted coolant temperatures.

The invention relates to a method for operating a vehicle air-conditioning system in dependence on the difference between the temperature of the engine coolant at the inlet into the heating heat exchanger and the temperature of the air at the outlet out of the heating heat exchanger. The measured or estimated temperatures of the coolant at the inlet into the heating heat exchanger and of the air at the outlet out of the heating heat exchanger are checked to determine whether their values indicate fault states of components of the air-conditioning system.

An engine fluid temperature regulating system and method for an engine is provided. The system includes a bypass line configured to be connected in parallel with a heat exchanger between an inlet and an outlet thereof, as well as a flow regulator configurable to regulate a proportion of fluid flowing through the bypass line and heat exchanger, respectively, between the inlet and the outlet. A control unit may be provided to regulate the proportion of fluid flowing through the bypass line and heat exchanger, and temperature sensor may be provided to measure temperatures used to regulate the proportion of fluid flowing through the bypass line and heat exchanger.

An engine system having a coolant control valve unit includes a valve housing in which a passage having a coolant supplied from one side of the passage and exhausted to another side of the passage is formed, a valve configured to rotate with reference to a rotation center shaft, in which a closing portion closing the passage according to a rotation position and an opening portion opening the passage are formed in the valve with a predetermined interval in a rotation direction, an actuator configured to rotate the valve with reference to the rotation center shaft, and a controller configured to control the actuator according to driving conditions, and a bypass passage penetrating the closing portion of the valve may be formed in a state that the closing portion closes the passage.