A fluid flow control device controls flow of coolant in a motor vehicle motor cooling system. The flow control device includes first and second coolant inlets and first and second coolant outlets. The flow control device is operable selectively to direct coolant flowing into the device to flow out from the flow device through one or both of the first and second outlets in dependence on a temperature of fluid flowing through the device.

A method and a system for controlling a vehicle cooling system includes: a velocity prediction unit makes a prediction of at least one future velocity profile v.sub.pred for the vehicle; a temperature prediction unit predicts at least one future temperature profile T.sub.pred for at least one component in the vehicle, based on at least tonnage for the vehicle; information related to a section of road ahead of the vehicle and on the at least one future velocity profile v.sub.pred. A cooling system control unit controls the cooling system based on the at least one future temperature profile T.sub.pred and on a limit value temperature T.sub.comp.sub._.sub.lim for the respective at least one component in the vehicle so that a number of fluctuations of an inlet temperature T.sub.comp.sub._.sub.fluid.sub._.sub.in.sub._.sub.radiator for the cooling fluid flow into the radiator is reduced and/or so that a magnitude of the flow into the radiator is reduced when a temperature derivative dT/dt for the inlet temperature T.sub.comp.sub._.sub.fluid.sub._.sub.in.sub._.sub.radiator exceeds a limit value dT/dt.sub.lim for the temperature derivative.

The present disclosure provides an engine cooling system having a coolant temperature sensor to sense the temperature of coolant discharged from an engine; a radiator radiating heat while part of the coolant discharged from the engine is passed through the radiator; a coolant control valve unit to control coolant passing through the radiator and coolant supplied from the engine; and a control unit configured to control the temperature of coolant by controlling the coolant control valve unit according to the coolant temperature sensed by the coolant temperature sensor, wherein the control unit calculates a coolant temperature at an entrance of the engine using the sensed coolant temperature and a heat rejection rate of the engine based on the operation condition, calculates a temperature of coolant discharged from the radiator, and controls the opening degree of the coolant control valve unit using the coolant temperatures.

The present disclosure provides a method and system, for controlling a coolant circulating in an engine, including: selecting a reference inlet temperature for a coolant flowing through a coolant inlet of an engine; controlling an open rate of the coolant control valve unit based on the reference inlet temperature; sensing an actual inlet temperature of the coolant flowing through the coolant inlet of the engine; sensing an actual outlet temperature of a coolant flowing through a coolant outlet of the engine; calculating a difference value between the actual inlet temperature and the actual outlet temperature; and varying the reference inlet temperature according to the difference value.

A number of variations may include a thermal management system comprising: an engine, an exhaust heat recovery system, and a coolant system comprising a coolant circuit and a coolant pump wherein the coolant pump operates independently of the engine and is operated by an electronic control unit, and wherein the electronic control unit is constructed and arranged to operate the coolant pump after engine start up to limit coolant temperature below a predetermined value in and/or near the exhaust heat recovery system.

The present disclosure relates to a gas engine power generation system, having an engine configured to generate mechanical energy by burning an air-fuel mixture supplied from a mixer, which mixes air filtered by passing through an air cleaner, and fuel of a predetermined pressure which has passed through a zero governor, in which the gas engine power generation system converts the mechanical energy of the engine into electrical energy. The gas engine power generation system according to an embodiment of the present disclosure includes: an intake path having a first intake passage and a second intake passage in which air to be supplied to the mixer flows; an intake passage controller configured to open either one of the first intake passage or the second intake passage and to close the other one; a coolant pump configured to supply coolant to the engine; a radiator configured to dissipate heat of the coolant having passed through the engine; an intake air heater provided in the intake path at a portion where the second intake passage is formed, and configured to dissipate heat of the coolant having passed through the engine; a coolant passage controller configured to distribute the coolant, having passed through the engine, to the coolant pump, the radiator, and the intake air heater; and a controller configured to control operations of the intake passage controller, the coolant passage controller, and the coolant pump based on temperature of the coolant, having passed through the engine, and load information of the engine.

Methods and systems are providing for improving engine coolant level estimation to reduce engine overheating. The level of fluid in a coolant overflow reservoir is inferred based on the fluid level in a hollow vertical standpipe fluidically coupled to the reservoir at top and bottom locations. An ultrasonic sensor positioned in a recess at the bottom of the vertical standpipe transmits signals intermittently, receives their echoes upon reflection from the coolant surface, and estimates the fluid level in the standpipe based on echo times.

A heat radiation amount from the cooling water in the radiator is adjusted so that the temperature of the cooling water is less than a prescribed temperature that is a temperature higher than the threshold value if a load exerted on the internal combustion engine is not less than a predetermined load, while the heat radiation amount from the cooling water in the radiator is adjusted so that the heat radiation amount from the cooling water in the radiator is increased if the load exerted on the internal combustion engine is less than the predetermined load as compared with if the load exerted on the internal combustion engine is not less than the predetermined load.

In order to shift a rotation angle of a rotor to a region of a normal mode (for example, a region c) from a region of a heater cut mode (for example, a region e), the rotation angle needs to pass through a region where a flow rate of a refrigerant which is caused to flow through all branch channels becomes zero (a region d). When the refrigerant has a high temperature, there is a possibility of the refrigerant being not cooled, and boiling. Therefore, when a request to switch a normal mode and a heater cut mode is issued, permission/non-permission of switch of the mode is determined by comparison of a temperature of the refrigerant detected by the temperature sensor 26 and an upper limit temperature of the refrigerant.

A method for promoting regeneration of an exhaust aftertreatment component of an internal combustion engine includes: detecting a low load operating condition of the internal combustion engine; adjusting a pitch angle of one or more blades of a fan to reduce an air flow across a radiator in response to the detection of the low load operating condition; and increasing a rotational speed of the fan to increase a load on the internal combustion engine and to elevate temperature of an exhaust gas flowing across the exhaust aftertreatment component.