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.

The present disclosure provides an engine cooling system having a coolant temperature sensor, including a radiator disposed to release heat of coolant circulated in an engine; a coolant control valve unit controlling the coolant circulated in the radiator through opening rate of a valve having a coolant passage corresponding to the radiator; a second coolant temperature sensor sensing a coolant temperature at a coolant outlet side of the engine; a third coolant temperature sensor sensing the coolant temperature at the coolant outlet side of the radiator; and a control unit sensing second and third coolant temperatures through the second and third coolant temperature sensors, calculating a first coolant temperature at a coolant inlet side of the engine by calculating the second and third coolant temperatures, and calculating valve opening rate of the coolant control vale by using the first, second, and the third coolant temperature.

An engine cooling system has a coolant control valve unit and includes a cylinder head disposed on a cylinder block. The coolant control valve unit is configured to receive coolant from a coolant outlet side of the cylinder head to control coolant distributed to a heater and a radiator and to control coolant exhausted from the cylinder block. A control unit is configured to determine a heating priority mode according to operation conditions and to substantially open a first coolant passage corresponding to the heater by controlling the coolant control valve unit in the heating priority mode.

A heat accumulation and dissipation device (1) for an internal combustion engine (2) includes, in a cooling circuit (3) for circulating cooling water used to cool the internal combustion engine (2), a heat accumulator (7) for accumulating the cooling water, and an exhaust heat recovery device (9) for recovering the heat of exhaust gas through the cooling water, wherein when the internal combustion engine (2) is started, heat is dissipated by sending the cooling water of the heat accumulator (7) to the internal combustion engine (2). The cooling circuit (3) includes a heat accumulation and dissipation circuit (8) configured to perform heat accumulation and dissipation while circulating the cooling water between the internal combustion engine (2) and the heat accumulator (7), and the heat accumulator (9) is arranged upstream of the heat accumulator (7) of the heat accumulation and dissipation circuit (8).

An electronic thermostat, into which cooling water is flowed from a cylinder head of an engine through a first inlet, controls the flow rate of the received cooling water supplied to outside ambient air exposure. The electronic thermostat includes a first valve for controlling the flow rate of the cooling water supplied to a first passage for connecting a first outlet of the electronic thermostat and a water pump and includes a second valve for controlling the flow rate of the cooling water flowing through a second passage for connecting the outlet of a radiator and a cylinder block of the engine.

Methods and systems are provided for monitoring a status of a heater core isolation valve (HCIV) housing in an engine coolant circuit including a first coolant loop and a second coolant loop. In one example, a method may include indicating degradation of the HCIV based on a difference between a first coolant loop temperature and a second coolant loop temperature upon activation of coolant system pumps and deactivation of a positive temperature coefficient (PTC) heater housed in the cabin heating loop.

A system includes a coolant pump and a first rotary valve. The coolant pump is configured to be mechanically driven by an engine and to send coolant to an inlet of the engine. The first rotary valve is configured to receive coolant from an outlet of the engine and to send coolant to a first radiator and a heater core. The first rotary valve is adjustable to a zero flow position to prevent coolant flow to the first radiator and the heater core and thereby increase a rate at which the engine warms coolant flowing therethrough.

A system includes a coolant pump and a first rotary valve. The coolant pump is configured to be mechanically driven by an engine and to send coolant to an inlet of the engine. The first rotary valve is configured to receive coolant from an outlet of the engine and to send coolant to a first radiator and a heater core. The first rotary valve is adjustable to a zero flow position to prevent coolant flow to the first radiator and the heater core and thereby increase a rate at which the engine warms coolant flowing therethrough.

Systems and methods for regulating an outlet coolant temperature of a genset and an inlet coolant temperature of the genset are provided. A load condition of the genset may be determined. An operating mode can be selected from between a first mode associated with a first load condition and a second mode associated with a second load condition responsive to determining the load condition of the genset. The first mode and the second mode may be configured to determine a target inlet coolant temperature using one or more control loops. The target inlet coolant temperature may be determined using the selected operating mode, a target outlet coolant temperature and the outlet coolant temperature. The outlet coolant temperature may be regulated based on the determined target inlet coolant temperature and the inlet coolant temperature by adjusting an operation of one or more coolant valves.