New energy vehicles heating system 1
There are two main types of electric vehicle air conditioning heating systems: PTC thermistor heaters and heat pump systems. The working principles of these systems are very different.
PTC thermistor heating system
PTC is the abbreviation of Positive Temperature Coefficient, which refers to semiconductor materials or components with a large positive temperature coefficient. Simply put, it increases the temperature by energizing the thermistor to make the resistor heat up. The electric irons and curling irons we use in our daily lives are all based on this principle. At present, most electric vehicles in China use PTC heating. Some models use PTC to directly heat the cold air. This method is more efficient, but the high pressure entering the cockpit brings safety hazards. Therefore, water is currently used as the medium. PTC heats the water and sends it to the heating core of the air conditioning duct, and then the warm air is blown into the car through the blower.
The heating system using water as the medium consists of a blower, an electric heater (PTC), a heater water pump, a heater core, etc. When the automatic air conditioning system is in heating mode, the heater heats the coolant under the action of high-voltage electricity, and the high-temperature coolant is pumped into the heater core by the heater water pump. At the same time, the cold and warm temperature control motor rotates the damper to the heating position, and the airflow flows through the heater core under the action of the blower to generate heat transfer. Before entering the passenger compartment, the outside air is mixed with the heated air to blow out comfortable warm air. Although this approach will reduce the heating efficiency, safety is guaranteed and it is also the current mainstream.
The biggest drawback of PTC heating is power consumption, which affects the range of pure electric vehicles, especially in cold winter. Take a 2kW PTC as an example. It consumes 2kWh of electricity for one hour at full power. If a car consumes 15kWh of electricity for every 100 kilometers, 2kWh will lose 13 kilometers of range. Many northern car owners complain that the range of electric vehicles has shrunk too much, partly because of the power consumption of PTC heating. In addition, in cold winter weather, the activity of materials in the power battery decreases, the discharge efficiency is not high, and the range will also be discounted.
