What's the difference between air-cooled PCS and liquid-cooled PCS?

The difference between air-cooled PCS and liquid-cooled PCS is mainly reflected in the cooling method, heat dissipation efficiency, system structure, cost and application scenarios. The following is a detailed comparison of these aspects:

Difference 1. Cooling method

1. Air-cooled PCS: Use air as the cooling medium, blow air through the PCS components through fans and other equipment, and use the convection heat transfer principle to take away the heat. The main equipment of the air-cooling system includes air conditioning, air ducts and module fans. The fan is installed in front of the module to take the heat dissipated by the battery cells in the module to the prefabricated cabin air duct, and then the air conditioning system in the prefabricated cabin dissipates the heat.

2. Liquid-cooled PCS: Use liquids such as water and ethylene glycol as cooling media, circulate the coolant to the PCS components through the liquid cooling plate or liquid cooling pipeline, and use the convection and conduction heat exchange principles of the liquid to take away the heat. The liquid cooling system mainly includes a refrigerant system and an antifreeze system. The antifreeze system drives the antifreeze to circulate in the liquid cooling plate through a water pump to take away the heat generated during the battery operation.

Difference 2. Heat dissipation efficiency

1. Air-cooled PCS: Due to the relatively low specific heat capacity and thermal conductivity of air, the heat dissipation efficiency of the air-cooled system is relatively limited. Although it can meet the temperature control requirements of most current energy storage power stations, with the continuous improvement of the single unit scale and energy density of energy storage projects, the shortcomings of the air-cooled system in heat dissipation efficiency are gradually emerging.

2. Liquid-cooled PCS: The liquid-cooled system uses a coolant with a high thermal conductivity as a medium and can contact the PCS components more directly, so the heat dissipation efficiency is higher. The liquid-cooled system can better cope with the heat dissipation needs of high-energy-density, large-scale energy storage projects.

Difference 3. System structure

1. Air-cooled PCS: The system structure is relatively simple, mainly composed of fans, air conditioners, air ducts and other equipment. The overall structure of the air-cooled system is relatively loose, and a large area of ​​heat dissipation channels needs to be deployed, which has a certain impact on the space utilization of the energy storage power station.

2. Liquid-cooled PCS: The system structure is more compact and complex, including liquid cooling plates, water pumps, refrigerant systems, etc. The liquid cooling system can use space more efficiently and improve the energy density and overall efficiency of the energy storage power station.

Difference 4. Cost

1. Air-cooled PCS: The initial investment cost is relatively low, but the long-term operation and maintenance costs may be high. Due to the limited heat dissipation efficiency of the air-cooled system, it may be necessary to increase the number and power of fans to maintain the appropriate temperature range, thereby increasing energy consumption and operating costs.

2. Liquid-cooled PCS: The initial investment cost is relatively high, but the long-term operation and maintenance costs may be lower. The liquid cooling system has higher heat dissipation efficiency and lower energy consumption, which can reduce the overall cost over the entire life cycle.

Difference 5. Application scenarios

1. Air-cooled PCS: It is suitable for scenarios where the energy storage project has a small scale, low energy density, and low heat dissipation requirements. In the initial development stage of the energy storage system or when the budget is limited, air-cooled PCS is a feasible option.

2. Liquid-cooled PCS: It is more suitable for scenarios where the energy storage project has a large scale, high energy density, and strict heat dissipation requirements. With the continuous development of energy storage technology and the improvement of application requirements, liquid-cooled PCS will become the mainstream choice.

Conclusion

To sum up, there are significant differences between air-cooled PCS and liquid-cooled PCS in terms of cooling methods, heat dissipation efficiency, system structure, cost, and applicable scenarios. When selecting PCS, comprehensive considerations need to be made based on specific application requirements and scenarios.