Hydrogen compressors can be classified into two types based on their operating principle: positive displacement and dynamic, with positive displacement being the most common. Positive displacement compressors are further divided into reciprocating piston compressors and rotary compressors. 1. Reciprocating piston compressors change the working volume of gas by the reciprocating motion of a piston within a cylinder; piston compressors have a long history and mature production technology. 2. Rotary compressors include vane (sliding vane) rotary compressors and screw compressors. Most domestically produced air conditioners use rotary compressors; screw compressors are mainly used in large refrigeration equipment, and are also widely used in large shopping malls and office buildings.
Like other gases, hydrogen can be pressurized using reciprocating or centrifugal compressors to meet process requirements. In each typical application, the type of compressor should be determined based on the hydrogen flow rate and the required pressure. For large and medium-sized hydrocracking units, reciprocating compressors are used for new hydrogen, while centrifugal compressors are used for circulating hydrogen.