Disclosed are a hybrid electric vehicle capable of controlling starting of an engine in order to more efficiently realize heating and an engine control method therefor. The method of controlling an engine of a hybrid electric vehicle of the disclosure includes determining whether the engine is in a warmed-up state when a fully automatic temperature control system makes a heating request, making an engine startup request for heating to an engine management system configured to control the engine when the engine is in the warmed-up state, and selectively requesting the engine management system to perform cylinder deactivation (CDA) control on at least some of a plurality of cylinders of the engine depending on whether the engine is in an idling state.

A heat management device for a vehicle equipped with heat related systems includes an acquisition unit and a flow rate control unit. The acquisition unit is configured to acquire a temperature related value from electronic control devices corresponding to the heat related systems. The temperature related value includes a temperature adjustment related value and/or an upper limit value. The flow rate control unit is configured to control switching devices that switch flow rate of fluid flowing through the heat related systems from a common path in which the fluid can circulate between the heat related systems. The flow rate control unit controls flow rate of the fluid flowing from the common path to the heat related systems by controlling the switching devices in response to the temperature related value acquired by the acquisition unit for a predetermined scene of the vehicle.

A vehicular heat management system includes a refrigerant circulation line configured to cool or heat a passenger compartment by generating a hot air or a cold air depending on a flow direction of a refrigerant, a cooling water circulation line configured to heat the passenger compartment with waste heat of an engine by allowing cooling water of the engine to circulate through a heater core, a refrigerant-cooling water heat exchanger disposed in the cooling water circulation line to allow the refrigerant and the cooling water to exchange heat, and an engine cooling water independent circulation unit configured to allow the cooling water passed through the engine to bypass the heater core and the refrigerant-cooling water heat exchanger.

A vehicular heat management system includes a refrigerant circulation line configured to cool or heat a passenger compartment by generating a hot air or a cold air depending on a flow direction of a refrigerant, a cooling water circulation line configured to heat the passenger compartment with waste heat of an engine by allowing cooling water of the engine to circulate through a heater core, a refrigerant-cooling water heat exchanger disposed in the cooling water circulation line to allow the refrigerant and the cooling water to exchange heat, and an engine cooling water independent circulation unit configured to allow the cooling water passed through the engine to bypass the heater core and the refrigerant-cooling water heat exchanger.

A control device is installed in the vehicle that is able to execute a fuel cut that stops fuel supply to an engine in a state in which the engine is rotating. In a case where there is a request for the fuel cut while there is a heating request in which heating of a vehicle cabin is performed using heat of an engine coolant, when a blowout port mode of air conditioning air is set to a defroster mode or a bi-level mode, the control device prohibits the fuel cut.

A control device is installed in the vehicle that is able to execute a fuel cut that stops fuel supply to an engine in a state in which the engine is rotating. In a case where there is a request for the fuel cut while there is a heating request in which heating of a vehicle cabin is performed using heat of an engine coolant, when a blowout port mode of air conditioning air is set to a defroster mode or a bi-level mode, the control device prohibits the fuel cut.

A thermal system for a vehicle includes a high temperature coolant loop thermally coupled to a heater core, a low temperature coolant loop thermally coupled to at least one of an electric motor and power electronics, and a first four-way valve configured to selectively fluidly couple the high temperature coolant loop and the low temperature coolant loop such that coolant heated by the electric motor and/or the power electronics is directed to the heater core to facilitate heating of an airflow passing thereby.

An embodiment method for controlling a heating, ventilation, and air conditioning (HVAC) system of a vehicle includes determining a target subcooled temperature of a refrigerant based on a temperature and a pressure of the refrigerant discharged from an outlet of a compressor when the compressor operates, calculating a change in enthalpy of the refrigerant based on the determined target subcooled temperature in a process of condensing and subcooling the refrigerant, calculating a change in enthalpy of air passing over an exterior surface of a condenser based on the calculated refrigerant enthalpy change, and calculating a required fan duty of a cooling fan based on the calculated air enthalpy change, wherein the cooling fan is configured to blow the air to the condenser.

An embodiment method for controlling a heating, ventilation, and air conditioning (HVAC) system of a vehicle includes determining a target subcooled temperature of a refrigerant based on a temperature and a pressure of the refrigerant discharged from an outlet of a compressor when the compressor operates, calculating a change in enthalpy of the refrigerant based on the determined target subcooled temperature in a process of condensing and subcooling the refrigerant, calculating a change in enthalpy of air passing over an exterior surface of a condenser based on the calculated refrigerant enthalpy change, and calculating a required fan duty of a cooling fan based on the calculated air enthalpy change, wherein the cooling fan is configured to blow the air to the condenser.

A heating system for a vehicle having a power plant with a power plant coolant loop, and a method of operation, is disclosed. The heating system may include a HVAC module and a heater core coolant loop. The HVAC module includes a heater core. The heater core coolant loop includes a three-way valve having an inlet engaging the heater core for receiving a coolant, a first outlet that directs the coolant back into the heater core coolant loop, and a second outlet that directs the coolant into the power plant; a coolant pump for pumping the coolant through the heater core coolant loop; and a coolant heater located upstream of the heater core that selectively heats coolant flowing therethrough. Also, a coolant line receives the coolant from a heater core outlet of the power plant and directs the coolant into the heater core coolant loop.