Thermal management system research: the mass production of CO? heat pumps, integrated controllers and other innovative products accelerates

Thermal management of new energy vehicles coordinates the control of vehicle heat and ambient heat from the perspective of the system and the entire vehicle, keeping each component working in the optimal temperature range to ensure efficient collaboration of the vehicle, thereby improving economy, power, energy conservation and environmental protection.

Thermal management of new energy vehicles covers motors, battery systems and cockpit air conditioning.
The installation rate of heat pump air conditioners for new energy passenger cars exceeds 20%, and heat pump air conditioners are penetrating into mid- to low-end models
Heat pump air conditioning is the most effective solution for heating battery-electric vehicles. Consumers have been anxious about the range of battery-electric vehicles. In the absence of breakthroughs in battery technology, the efficiency coefficient of a heat pump is 2-3 times higher than that of PTC heating, which can effectively extend the cruising range by more than 20%.

At present, heat pump air conditioners are primarily installed on mid-to-high-end new energy passenger cars (especially battery-electric passenger cars), mainly because: new energy passenger cars develop rapidly and the market scale effect is obvious; the content-per-car value of heat pump air conditioning systems is higher than that of PTC systems by RMB2,000-3,000, and mid-to-high-end models pose higher profit margins, which can effectively make up the difference.

From January to September 2023, a total of 5.912 million new energy passenger cars were sold in China, of which approximately 1.495 million units or 25.3% were equipped with heat pump air conditioners as standard.

In 2023, the average selling price of a new car with standard heat pump air conditioning dropped from RMB200,000~250,000 to RMB150,000~200,000. Mid- to low-end domestic electric models which are promoted for sales goals have been equipped with heat pump air conditioning systems, and the penetration rate of heat pumps is expected to continue to increase. By 2027, the penetration rate of heat pump air conditioning for new energy vehicles in China will be close to 60%.

By analyzing and comparing the thermal management systems of 18 major OEMs, ResearchInChina found that most OEMs develop thermal management system technical solutions of "multi-way valve + heat pump + waste heat recovery".

For example, Tesla’s fourth-generation thermal management system consists of Octovalve + heat pump system + liquid cooling + waste heat recovery to achieve integrated vehicle thermal management. The thermal management system of BYD’s e-Platform 3.0 includes Nonavalve + heat pump system + refrigerant direct cooling + waste heat recovery. Xpeng X-HP2.0 intelligent thermal management system contains a ten-way valve, a heat pump and automotive integrated thermal management. The automotive integrated thermal management technology of the Neta Haozhi Platform boasts a heat pump air conditioner, 3 sets of electronic water pumps and 2 sets of "4-way" valves. Xiaomi’s 10-way valve thermal management system includes a 10-way valve, a heat pump air conditioner and 800V.

The steady growth of the thermal management system market for new energy vehicles directly propels the development of thermal management parts. In recent years, the number of players in the thermal management market for new energy vehicles has increased significantly, which has led to rising product capacity and intensified market competition. Amid the competition, many OEMs have successively released their latest technologies and products.

1. There will be a breakthrough in the development of R744 refrigerant for domestic new energy vehicle heat pumps

Heat pump air conditioning has replaced PTC to become the standard configuration of new energy vehicles. R134a is still the main refrigerant in domestic new energy vehicles.

At present, in the global market, R744 (carbon dioxide) is the best refrigerant. R744 has advantages like environmental protection, safety and good heating performance, but it requires high pressure, high-pressure and high-temperature resistance of compressors, pipelines and valves, pressure sensors which monitor the system pressure, so it poses more R&D and manufacturing costs.

In the future, CO? heat pump systems using R744 will become the mainstream. Domestic vendors have begun to lay out the CO? heat pump market:

2.Automaker CO? heat pump cooperation: automakers actively cooperate with upstream and downstream partners in the industrial chain to jointly make the CO? heat pump thermal management system industry bigger and stronger and promote the development of automotive CO? heat pump technology. In April 2023, the Technical Center of Dongfeng signed the CO? Heat Pump Industry Chain Cooperation Agreement with its 17 partners. The technical center of Dongfeng will start the technical route of "CO? direct heat pump+integrated design".

3.Domestic parts vendors have laid out CO? heat pumps. In the field of new energy vehicle parts, the products such as CO? electronic expansion valves, CO? stop valves/check valves/regulating valves produced by Sanhua Intelligent Controls were mass-produced and installed in 2022. In 2023, Shanghai Kelai Mechatronics Engineering Co., Ltd. Mass-produced CO? high-pressure pipeline systems and installed them in vehicles. Welling developed a rotary electric compressor suitable for CO?.

PTC heaters have become the main solution for automotive heat pump air conditioning to cope with ultra-low temperature.
Because there is no engine in new energy vehicles, heaters are essential in the environment below -10?. PTC heaters boast advantages like low cost, simple structure, fast heat output and little influence from external environment, but the disadvantage lies in relatively high energy consumption. At present, most mainstream models adopt the solution of heat pump +PTC. With the continuous breakthrough of battery technology, there will be an enormous market for PTC heating in the field of new energy vehicles in the future.

At present, mid-to-low-end new energy vehicles mainly use PTC heating, and a certain number of models with heat pump air-conditioning still use PTC as an auxiliary heating method. On average, a new energy passenger car uses two PTC heaters (a air-cooled heater and a water-cooled heater), with the content-per-car value of RMB800-1,500. We estimate that the market size of PTC heaters for new energy vehicles in China will hit about RMB11 billion in 2025.

For example, Tesla has added an additional PTC heater to the heat pump system of Model Y. This PTC heater uses the 12V voltage which is also seen in traditional fuel vehicles, and Model Y is also equipped with a separate 12V battery. The PTC heating system is powered by a single 12V battery, but its power is far less than the PTC heating power of traditional air conditioners. It can not only save electricity, but also effectively alleviate the low-temperature heating effect of heat pump air conditioning.

In addition to Tesla, BYD, NIO and HiPhi all add PTC heaters to their heat pump systems.

In addition to the solution of heat pump air conditioning plus PTC heating, the industry leverages high-voltage and high-power water heating electric heaters to cope with the impact of low temperatures on batteries in winter. Traditional new energy vehicle water heaters use PTC ceramic chip heating technology. Due to its material characteristics and complex production process, this technology usually has an upper limit of operating voltage, namely 750V, which cannot meet the 800V fast charging requirements of new energy vehicles. When applied to 800V high voltage conditions, it will incur obvious insulation problems, which will threaten to the safety of vehicles. At present, only a few domestic vendors can supply 800V PTC water heaters, with limited mass production and delivery.

Integrated development of thermal management controllers and automotive electronic and electrical architectures
By monitoring the equipment temperature in real time, thermal management controllers intelligently adjust the rotating speed and power of the heat dissipation equipment to ensure that the equipment is in the optimal temperature range, stable in operation and longer in service life. In addition, thermal management controllers have high precision and can quickly respond to temperature abnormalities in high-performance electronic equipment such as processors and graphics cards, thereby avoiding damage to equipment and data. With the centralization of automotive electronic and electrical architectures, thermal management controllers and domain controllers will be integrated into central integrated systems.

In the Audi e-tron thermal management system, the thermal management controller adopts CAN bus, while the PTC, EXV, ACCM, PT, four-way valve and stop valve use LIN.

Tesla has integrated the thermal management controller into the body controller to control the valve and electronic water pump.

In addition to air conditioning systems, refrigerant, PTC heaters, electronic water pumps and thermal management controllers, hot pipe system technology includes technology integration, battery thermal management, electric compressors, electronic expansion valves, pipe street lamps and other parts. Driven by the development of electrification and integration, these thermal management components will undergo technological iteration and reform.