With the rapid development of the electric vehicle market, users are placing increasingly high demands on the range, charging speed, charging convenience, and other aspects. However, there are still shortcomings and inconsistency issues in the charging infrastructure at home and abroad, causing users to often encounter problems such as the inability to find suitable charging stations, long waiting times, and poor charging effect when traveling.
Huawei Digital Energy tweeted: ”Huawei’s full liquid-cooled supercharger helps create high-altitude and fast-charging high-quality 318 Sichuan-Tibet Supercharging Green Corridor.” The article notes that these fully liquid-cooled recharge terminals have the following characteristics:
1. The maximum output power is 600KW and the maximum current is 600A. It is known as ”one kilometer per second” and can provide maximum charging power at high altitudes.
2. Full liquid cooling technology ensures the high reliability of the equipment: on the plateau, it can withstand high temperatures, high humidity, dust, and corrosion, and can adapt to various difficult line operating conditions.
3. Suitable for all models: The charging range is 200-1000V, and the charging success rate can reach 99%. It can match passenger cars such as Tesla, Xpeng, and Lili, as well as commercial vehicles such as Lalamove, and can achieve: ”Walk up to the car, charge it, charge it, and go.”
Liquid-cooled supercharging technology not only provides high-quality services and experience to domestic new energy vehicle users but will also help further expand and promote the new energy vehicle market. This article will help you understand liquid cooling recharge technology and analyze its market status and future trends.
What is liquid cooling overcharge?
Liquid cooling recharge is achieved by creating a special liquid circulation channel between the cable and the charging gun. This channel is filled with coolant fluid to remove heat. The power pump promotes the circulation of liquid coolant, which can effectively dissipate the heat generated during the charging process. The power part of the system uses liquid cooling and is completely isolated from the external environment, therefore meeting the IP65 design standard. At the same time, the system also uses a powerful fan to reduce heat dissipation noise and improve environmental friendliness.
Technical characteristics and advantages of supercharged liquid cooling.
1. Higher current and faster charging speed.
The charging battery’s current output is limited by the charging gun wire, which typically uses copper cables to carry the current. However, the heat generated by a cable is proportional to the square of the current, meaning that as the charging current increases, the cable is more likely to generate excess heat. To reduce the problem of cable overheating, the cross-sectional area of the wire must be increased, but this will also make the charging gun heavier. For example, the current national standard 250A charging gun typically uses an 80mm² cable, which makes the charging gun overall heavier and not easy to bend.
If you need to achieve a higher charging current, a dual gun charger is a viable solution, but this is only suitable for special cases. The best solution for high-current charging is usually liquid-cooled charging gun technology. This technology effectively cools the inside of the charging gun, allowing it to handle higher currents without overheating.
The internal structure of the liquid-cooled charging gun includes cables and water pipes. Typically, the cross-sectional area of the 500A liquid-cooled charging gun cable is only 35mm², and the generated heat is effectively dissipated by the coolant flow in the water pipe. Because the cable is thinner, a liquid-cooled charging pistol is 30 to 40% lighter than a conventional charging pistol.
Additionally, a liquid-cooled charging gun also needs to be used with a cooling unit, which includes water tanks, water pumps, radiators, fans, and other components. The water pump is responsible for circulating the coolant inside the nozzle line, transferring the heat to the radiator, and then blowing it out with the fan, thereby providing greater current carrying capacity than conventional naturally cooled nozzles.
2. The gun cord is lighter and the charging equipment is lighter.
3. Less heat, fast heat dissipation, and high safety.
Conventional loading boilers and semi-fluid-cooled loading boilers typically use air-cooled heat rejection systems in which air enters the boiler body from one side, removes the heat generated by the electrical components and rectifier modules, and then exits the boiler body. fold the body to the other side. However, this method of heat removal has some problems because the air entering the pile may contain dust, salt spray, and water vapor, and these substances may adhere to the surface of the internal components, resulting in reduced insulation performance of the pile. systems and reduced heat dissipation efficiency, which reduces charging efficiency and shortens equipment life.
For conventional charging boilers and semi-fluid-cooled loading boilers, heat removal and protection are two contradictory concepts. If protective performance is important, thermal performance may be limited, and vice versa. This complicates the design of such piles and requires full consideration of heat dissipation while protecting the equipment.
The all-liquid-cooled boot block uses a liquid-cooled boot module. This module has no air ducts at the front or rear. The module uses coolant circulating through the internal liquid cooling plate to exchange heat with the external environment, allowing the boot unit’s power section to achieve a completely enclosed design. The radiator is placed on the outside of the pile and the coolant inside transfers heat to the radiator and then the outside air carries away the heat from the surface of the radiator.
In this design, the liquid-cooled charging module and electrical accessories inside the charging block are completely isolated from the external environment, achieving an IP65 protection level and increasing system reliability.
4. Low charging noise and higher protection.
Both traditional and liquid-cooled charging systems have built-in air-cooled charging modules. The module is equipped with several high-speed small fans that typically produce noise levels over 65 decibels during operation. In addition, the charging pile itself is equipped with a cooling fan. Currently, air-cooled chargers often exceed 70 decibels when running at full power. This may not be noticeable during the day, but at night it can cause even more disruption to the environment.
Therefore, increased noise from charging stations is the most common complaint from operators. To solve this problem, operators need to take corrective measures, but these are often costly and have limited effectiveness. Ultimately, power-limited operation may be the only way to reduce noise interference.
The all-liquid-cooled boot block adopts a double-circulation heat dissipation structure. The internal liquid cooling module circulates coolant through the water pump to dissipate heat and transfer the heat generated inside the module to the finned heatsink. A large fan or air conditioning system with low speed but high air volume is used outside the radiator to effectively dissipate heat. This type of low-speed volume fan has a relatively low noise level and is less harmful than the noise of a high-speed small fan.
In addition, a fully liquid-cooled supercharger may also have a split heat dissipation design, similar to the principle of split air conditioners. This design protects the cooling unit from people and can even exchange heat with pools, fountains, etc. for better cooling and reduced noise levels.
5. Low total cost of ownership.
When considering the cost of charging equipment at charging stations, the total life cycle cost (TCO) of the charger must be considered. Traditional charging systems using air-cooled charging modules typically have a service life of fewer than 5 years, while current charging station operating lease terms are typically 8-10 years. This means that the charging equipment must be replaced at least once during the life of the facility. In contrast, a fully liquid-cooled charging boiler can have a service life of at least 10 years, covering the entire life cycle of the power plant. Additionally, unlike an air-cooled module’s boot block, which requires frequent opening of the cabinet for dust removal and maintenance, an all-liquid-cooled boot block only needs to be flushed after the dust has accumulated on the external heatsink, making maintenance difficult. comfortable.
Therefore, the total cost of ownership of a full liquid-cooled charging system is lower than that of a traditional charging system using air-cooled charging modules, and with the widespread adoption of full liquid-cooled systems, its cost-effectiveness advantages will become more evident more obvious.
Defects in liquid cooling supercharging technology.
1. Poor thermal balance
Liquid cooling is still based on the principle of heat exchange due to temperature differences. Therefore, the problem of temperature difference inside the battery module cannot be avoided. Temperature differences may result in overcharging, overcharging, or undercharging. Discharge of individual module components during charging and discharging. Overcharging and over-discharging batteries can cause battery safety problems and shorten battery life. Undercharging and discharging reduce the battery’s energy density and shorten its operating range.
2. Heat transfer power is limited.
The charging rate of the battery is limited by the rate of heat dissipation, otherwise, there is a risk of overheating. The heat transfer power of cold plate liquid cooling is limited by temperature difference and flow rate, and the controlled temperature difference is closely related to the ambient temperature.
3. There is a high risk of temperature runaway.
Battery thermal runaway occurs when the battery generates a large amount of heat in a short period. Due to the limited rate of sensible heat dissipation due to temperature differences, large heat accumulation results in sudden growth. temperature, which results in a positive cycle between the battery heating up and the temperature rising, causing explosions and fires, as well as leading to thermal runaway in neighboring cells.
4. Large parasitic power consumption.
The resistance of the liquid cooling cycle is high, especially given the limitations of the battery module volume. The cold plate flow channel is usually small. When the heat transfer is large, the flow rate will be large, and the pressure loss in the cycle will be large. , and the power consumption will be large, which will reduce the battery performance when overcharging.
Market status and development trends for liquid cooling refills.
Market status
According to the latest data from the China Charging Alliance, there were 31,000 more public charging stations in February 2023 than in January 2023, up 54.1% from February. As of February 2023, alliance member units reported a total of 1.869 million public charging stations, including 796,000 DC charging stations and 1.072 million AC charging stations.
As the penetration rate of new energy vehicles continues to rise and support facilities such as loading piles rapidly develop, new liquid-cooled supercharging technology has become the subject of competition in the industry. Many new energy vehicle companies and piling companies have also begun to conduct technological research and development and plan to inflate prices.
Tesla is the first car company in the industry to begin mass adoption of supercharged liquid-cooled units. It has currently deployed more than 1,500 supercharging stations in China, with a total of 10,000 supercharging units. The Tesla V3 supercharger features an all-liquid-cooled design, a liquid-cooled charging module, and a liquid-cooled charging gun. One pistol can charge up to 250 kW/600 A, increasing the range by 250 kilometers in 15 minutes. The V4 model will be produced in batches. The charging installation also increases the charging power to 350 kW per gun.
Subsequently, the Porsche Taycan introduced the world’s first 800 V high-voltage electrical architecture and supports powerful 350 kW fast charging; The global limited edition Great Wall Salon Mecha Dragon 2022 has a current of up to 600 A, a voltage of up to 800 V and a peak charging power of 480 kW; peak voltage up to 1000 V, current up to 600 A and peak charging power 480 kW; Xiaopeng G9 is a production car with an 800V silicon battery; carbide voltage platform and is suitable for 480 kW ultra-fast charging.
At present, the major charger manufacturing companies entering the domestic liquid-cooled supercharger market mainly include Inkerui, Infineon Technology, ABB, Ruisu Intelligent Technology, Power Source, Star Charging, Te Laidian, etc.
The Future Trend of Recharging Liquid Cooling
The field of supercharged liquid cooling is in its infancy and has great potential and broad development prospects. Liquid cooling is a great solution for high-power charging. There are no technical problems in the design and production of high-power charging battery power supplies at home and abroad. It is necessary to resolve the issue of cable connection from the power supply of the high-power charging battery to the charging gun.
However, the adoption rate of high-power liquid-cooled supercharged piles in my country is still low. This is because liquid-cooled charging pistols have a relatively high cost, and fast-charging systems will open up a market worth hundreds of billions of dollars in 2025. According to publicly available information, the average price of charging units is about 0.4 RMB/W.
The price of 240kW fast charging units is estimated to be around 96,000 yuan, according to the prices of liquid cooling charging cables at Rifeng Co., Ltd. At the press conference, which costs 20,000 yuan per set, it is assumed that the charger is liquid-cooled. The cost of the gun is approximately 21% of the cost of the charging pile, making it the most expensive component after the charging module. As the number of new fast-energy charging models increases, the market area for high-power fast-charging batteries in my country is expected to be approximately 133.4 billion yuan by 2025.
In the future, liquid cooling recharge technology will further accelerate penetration. The development and implementation of powerful liquid-cooled supercharging technology still has a long way to go. This requires collaboration between car companies, battery companies, piling companies, and other parties.
Only in this way can we better support the development of China’s electric vehicle industry, further promote streamlined charging and V2G, and promote energy saving and emission reduction in, a low-carbon approach. and green development, and accelerate the implementation of the “double carbon” strategic goal.
Post time: May-06-2024