Vehicular air-conditioning system and control method of same

An air-conditioning system provided for a vehicle that includes:

• an electric pump that circulates coolant at a flowrate according to a speed of the electric pump between an engine and a heater core;
• and
• an engine controlling device that controls starting/stopping of the electric pump, as well as the speed of the electric pump when the electric pump is being driven, based on a driving state of the engine, and drives the electric pump at a speed according to a required flowrate that is input when a flowrate is required;
• the air-conditioning system performing air-conditioning by blowing supply air, which is produced by controlling an air-heating amount by the heater core through which the coolant is circulated, out into a vehicle cabin from an air outlet,
• the air-conditioning system further comprising:
• a blower fan that is driven to produce the supply air;
• a coolant temperature detecting device that detects a temperature of the coolant;
• an air-conditioning controlling device that:
• controls operation of the blower fan and air-conditions the vehicle cabin with supply air produced by controlling the amount of air heated by the heater core, and stops operation of the blower fan when the temperature of the coolant detected by the coolant temperature detecting device is equal to or less than a set temperature during heating;
• sets the required flowrate of the coolant that is circulated to the heater core;
• and
• requires the engine controlling device to circulate the coolant of the required flowrate when the required flowrate has been set;
• and
• a vehicle speed detecting device that detects a vehicle speed;
• wherein the air-conditioning system is configured such that when the air-conditioning controlling device stops the blower fan because the temperature of the coolant is less than the set temperature an when the vehicle speed detecting device detects that the vehicle speed exceeds preset speed, the air-conditioning controlling device sets the required flowrate of the coolant based on the vehicle speed;
• and
• wherein when the air-conditioning controlling device stops the blower fan because the temperature of the coolant is less than the set temperature and when the vehicle speed detecting device detects that the vehicle speed is equal to or less than the preset speed, the required flowrate is set to 0.