In recent years, with the increasing capacity of energy storage cells, a large number of cells generate more and more heat during integrated work, and the cooling capacity of the air cooling system is no longer enough to meet the heat dissipation needs of the energy storage battery pack.
Just as the body needs to maintain a normal temperature, the operation of an energy storage power station also needs a stable temperature. If the temperature is too high or too low, it will affect the operating efficiency and service life of the energy storage power station. Especially in the case of high temperature, it may also cause safety accidents such as cell fire and system **.
There are many examples of related accidents. On April 18, 2021, a fire broke out at the energy storage facility at the Salt River Substation in Arizona, USA, and thick smoke billowed for five days. On April 16 of the same year, Beijing Daxing Energy Storage Power Station**, due to battery thermal runaway**, resulting in the death of 2 firefighters and the injury of 1 firefighter. According to incomplete statistics, in the past five years, there have been 45 fire accidents in energy storage power stations around the world, 5 in China, 3 in the United States, and 34 in South Korea.
Energy storage liquid cooling technology is one of the breakthrough technologies to meet the heat dissipation needs of energy storage systems.
Phases of development of thermal management of energy storage systems.
The thermal management of energy storage system has gone through two stages of development.
In the first stage, before 2021, the energy storage market is in a situation of air cooling and heat dissipation. "Air cooling" uses air as the heat exchange medium, through air conditioning and other mechanical equipment, so that the air is continuously circulated in the battery pack, and the temperature difference between the battery module and the air is used for heat transfer. The advantage is that the cost is lower and the installation is simple, and the disadvantage is that the heat dissipation effect is relatively poor, which is mainly used in small civil or commercial energy storage power stations.
In the second stage, from 2021 to the present, liquid cooling and heat dissipation technology has "sprung up", and its market share has continued to increase. "Liquid cooling", using liquid as a heat exchange mediumIt has a higher specific heat capacity than air, a higher thermal conductivity, and a fast cooling rate, which has a significant effect on reducing the local maximum temperature and improving the temperature consistency of the battery module. Therefore, liquid cooling is attracting more and more attention from the energy storage industry. According to the Advanced Industry Research Institute, the market penetration rate of liquid cooling is expected to reach about 45% in 2025.
In the stage of development, the battle between air cooling and liquid cooling continues. With the iterative upgrading of liquid cooling technology, it has brought a new breath to the development of energy storage heat dissipation.
Comparison of the advantages of air cooling and liquid cooling.
Paivo today revolves around bothSystem integration, battery pack temperature control effect, operating energy consumption and operation maintenanceand other aspects, and the air-cooled liquid cooling technology was compared and analyzed point by point.
1.System integration
The system integration of the liquid cooling solution is higher than that of the air cooling solution. For the same size energy storage container, the system capacity of the liquid-cooled solution is increased by 50% compared with that of the air-cooled solution；For energy storage containers of the same capacity, the liquid-cooled solution saves 40% of the floor space compared with the air-cooled solution.
2.Battery pack temperature control effect
The temperature uniformity of the battery pack under the liquid cooling scheme is better than that of the air-cooled scheme, and the risk of thermal runaway is much less than that of the air-cooled scheme. First of all, the heat exchange coefficient of liquid cooling is much higher than that of air cooling. Secondly, liquid cooling can precisely control the temperature difference of all cells3 (air cooling cannot accurately control the temperature).
3.Operational energy consumption
The operating energy consumption of the liquid-cooled solution is lower than that of the air-cooled solution. Under the same battery temperature under the same temperature, the energy consumption of air cooling is 2-3 times higher than that of liquid cooling; At the same power consumption, the temperature of the air-cooled battery pack is 3-5 % higher than that of the liquid-cooled battery.
4.Resistance to harsh environments
Liquid cooling systems are suitable for harsh environments such as seaside, high salt land, and deserts. Because of the low integration of the air-cooled system and the large number of components, the system components are susceptible to the erosion of high salt water vapor and sand, resulting in an increase in the system failure rateThe high integration advantage of liquid cooling system can significantly reduce the failure rate compared with air coolingTherefore, it is advisable to use a liquid cooling system.
Paiwo energy storage liquid cooling jumps out of "linear thinking".
At present, household storage is mainly air-cooled, and large storage is mainly air-cooled, and there is a trend of switching to liquid cooling, and the penetration rate of liquid cooling will continue to increase in the future. First of all, the scale of large-scale storage projects continues to increase, and the number of battery cells required will continue to increase; Secondly, the growth trend of cell capacity is obvious, and large cell products over 300Ah have been launched one after another. In the future, energy storage systems will put forward higher requirements for the heat dissipation efficiency and temperature difference control ability of temperature control, and liquid cooling will better match downstream needs.
The energy storage liquid cooling and temperature control management solution released by Paivo can greatly reduce the energy consumption of system operationCompared with traditional air conditioners, air cooling reduces energy consumption by more than 20% and increases service life by 20%. Paivo's full range of energy storage liquid cooling products have:Low cost, low energy consumption, high safetyadvantages,Through the intensive design of the liquid cooling solution, the energy density of the battery cell is greatly improved and the footprint is reduced.
In the future, the ability to customize liquid cooling solutions will become the core element of enterprise competition. Design capability is the core of competition for liquid cooling suppliers, because the different design solutions of integrators mean that liquid cooling needs to be jointly developed and integrated with the battery pack layout and pipeline design, so the customized design ability of Paiwo energy storage liquid cooling and temperature control management solutions is the core competitive element.