Hydrogen compressors come in various types, including diaphragm, reciprocating piston, rotary, screw, and turbine. The appropriate type is selected based on the flow rate, intake pressure, and exhaust pressure. Reciprocating compressors have a large flow rate, with a single-stage compression ratio typically between 3:1 and 4:1. Diaphragm compressors dissipate heat quickly, and the compression process is close to isothermal, allowing for higher compression ratios, up to 20:1. However, due to their smaller flow rate, they are mainly used in applications requiring higher hydrogen pressure but lower flow rates.
Generally, compressors with pressures below 30 MPa are typically reciprocating compressors, as experience has shown their high reliability, and they can be used independently in multi-stage compressors. For pressures above 30 MPa and smaller volumetric flow rates, diaphragm compressors can be selected. The advantage of diaphragm compressors is their reliable sealing under high pressure: because the sealing structure of their gas chamber is a diaphragm sandwiched between the cylinder head and cylinder block, secured by main bolts to form a static seal, ensuring no gas leakage. Furthermore, the diaphragm chamber is closed, preventing contact with any oil droplets, oil mist, or other impurities, ensuring that the incoming gas is not contaminated by external factors during compression. This is particularly advantageous for applications requiring highly pure media. The structure of a hydrogen compressor includes basic components (such as the crankcase, crankshaft, connecting rods, etc.), cylinder block components, plunger components, cooler components, safety protection and control systems, and other auxiliary components.