What are electric cars most afraid of? Two words: low temperature!
The power battery, the core component of electric vehicles, has a characteristic, that is, it must be in the right temperature environment (about 20-30 degrees Celsius) to perform its best performance. Once the temperature is too low, the battery activity will drop sharply, resulting in an avalanche of power, resulting in a big jump in the range of electric vehicles in winter.
In order to solve this problem, many electric vehicle manufacturers have proposed the concept of thermal management. In layman's terms, it is through the heating element, the electrical energy in the battery is consumed to heat up the battery, so that it reaches the optimal active temperature, thereby improving the cruising range of the electric vehicle. But this is a bit like the left foot stepping on the right foot to the sky, there are some effects, but it does not solve the fundamental problem.
However, human development is to challenge various problems, as the world's largest and most dynamic new energy vehicle market, how do Chinese electric vehicle brands solve this problem?
Winter measurement results are key
Heilongjiang Heihe -30 °C extremely cold environment, is the vast majority of electric vehicles "life forbidden area", but Nezha S withstood the harsh low temperature test, the function of stable operation, including the vehicle's air conditioning, battery thermal management, low temperature charging, power, handling and many other core projects.
Among them, with the help of Nezha S equipped with advanced HozonEPT4.0 constant temperature and heat management system, the vehicle's winter mileage has increased by 20%. You know, in such a low temperature state, electric vehicles due to battery activity attenuation, the mileage waist cut is also very normal, not down but up, what is the reason for this?
There are two major pain points in the thermal management performance of traditional electric vehicles:
Complex system: many pipelines, many components;
Poor environmental adaptability: difficulty in starting below -10 °C;
Most of the traditional thermal management adopts a split management strategy: the thermal management subsystems such as air conditioners, batteries, and cockpits are "independent", the heating pipes are complex, and it is easy to cause waste of heat energy and inefficient collaboration.
Different from the traditional thermal management strategy, HozonEPT4.0 constant temperature heat management system is an integrated thermal management system based on a highly integrated water source heat pump, which can integrate independent systems and unify management to minimize heat waste, minimize the consumption of battery power by the thermal management system, and ensure vehicle mileage.
HozonEPT4.0 constant temperature thermal management system realizes centralized management of crew compartment, battery, electric drive and electronic components through the "brain" of vehicle heat management. At the same time, the integrated design concentrates the physical part of all components and the control part of the component, so as to reduce the number of pipelines by 40%, increase reliability by 50%, and reduce the working temperature of the heat pump from the industry's -10 °C to -18 °C under the premise of meeting the comfort requirements, and with the intelligent/self-selected efficient insulation function to help Nezha S's winter endurance increase by 20%.
There is also a technological breakthrough in the heating of the car, Nezha S is equipped with intelligent dual-zone air conditioning, in the process of -20 °C, 40km/h driving, the temperature in the car is increased by 3 ° C per minute, and its performance is even better than that of traditional fuel vehicles, and finally do not have to worry about the endurance and reluctant to open the air conditioner, forced to helplessly use the "big cotton quilt heating".
Advanced technology Heat pump is the core
In different temperature conditions, there are differences in the temperature regulation methods of different types of models:
Fuel Vehicles:
Heating: through the engine waste heat;
Refrigeration: operated by compressor;
Heat pumpless system for new energy vehicles:
Heating: PTC heating;
New energy vehicle heat pump system:
Heating: heat pump heating;
From the temperature control methods of the above different vehicles, we can clearly see that the core difference in the thermal management of new energy vehicles is this heat pump system. In fact, its principle is similar to that of the air energy water heater on the market, which is through the principle of "compression release energy and pressure absorption", which absorbs heat from the cold external air and heats the car. In general, compared with the traditional PTC (electric heating wire) heating, after the use of heat pump system, the winter mileage of electric vehicles will be increased by about 10%.
It should be noted that the traditional heat pump cannot be started below -10 ° C, and the colder the weather, the lower the efficiency of the heat pump air conditioner, so the heating effect is worse. Generally equipped with a heat pump system of electric vehicles, will use PTC heating, although there is a certain effect, but often 6-8kW heating power, the vehicle endurance has a great impact.
The heat pump of Nezha S realizes the intelligent and collaborative control of all components of thermal management through the path of electric drive waste heat recovery, so as to achieve the overall energy efficiency optimization. Under the working conditions of outdoor ambient temperature -18 and open external circulation, the air outlet temperature can still be maintained at 48 ° C, at this time the COP of the entire system can reach more than 2.05, and the single heat pump can meet the heating requirements of the crew compartment without PTC. (COP: Converts the ratio of heat to input energy.)
At the same time, Nezha S adopts a minimalist integrated water source heat pump system, using a nine-way valve instead of two three-way valves and one four-way valve in the traditional heat pump solution. The nine-way valve can be accurately proportionally opened and closed, and the power can be adjusted steplessly through the VCU to achieve further energy saving.
Energy management algorithms are guarantees
The excellent winter comprehensive test performance of Nezha S is inseparable from its first domestic vehicle system-level intelligent thermal management strategy. By opening up the thermal management of the crew compartment, battery, electric drive, and electronic components, energy consumption is minimized under the premise of ensuring the heating of the cockpit and battery.
The main features of the thermal management system include:
Effective heat dissipation when the battery temperature is high to prevent thermal runaway accidents;
Preheat when the battery temperature is low to increase the battery temperature and ensure charging, discharging performance and safety at low temperatures;
Reduce the temperature difference in the battery pack, inhibit the formation of local hot zones, prevent the battery from decaying too quickly at high temperature positions, and reduce the overall life of the battery pack.
Limited and valuable energy, how to use efficiently, has become the core of Nezha S electric vehicle algorithm. Through the active heating of the thermal management system, the adaptive intelligent thermal management control strategy saves about 2% of the energy on a single charge; the battery pack is self-warming, the battery constant temperature liquid cooling system is adopted, the battery is self-heating during the discharge process, and the heat energy emitted by the motor is collected during the driving process, so that the winter endurance is increased by about 4%. From small flow control valves and water pumps, to heat pumps and cooling fans, fine control can be realized. Coupled with the detailed recovery of motor waste heat, battery waste heat and other energy, the efficiency is maximized.
A variety of "cut the details" of the energy management algorithm, saving every bit of heat energy, so that electric vehicles in the low temperature state to run farther.
summary
It is natural for electric cars to be afraid of low temperatures, just as primitive humans are powerless to fight back in the face of beasts of prey. However, with the birth of weapons, in the face of huge disparities in strength and speed, human beings also have the ability to reduce dimensions.
In the same way, it is precisely because of enterprises like Nezha that they have overcome difficulties through various technologies driven by wisdom and achieved a qualitative leap in the performance indicators of electric vehicles at low temperatures.
Therefore, Nezha S, which has an ultra-low temperature heat pump, is not afraid of low temperature.