制冷系统是中央空调系统至关重要的部分，其采用种类、运行方式、结构形式等直接影响了中央空调系统在运行中的经济性、高效性、合理性。

Refrigeration system is a crucial part of central air conditioning system. The type, operation mode and structure directly affect the economy, efficiency and rationality of central air conditioning system in operation.