Final answer:
The compression ratio and the clearance volume are two things in the design of a reciprocating compressor that control the efficiency of the compressor.
Step-by-step explanation:
In the design of a reciprocating compressor, two key factors that control the efficiency of the compressor are the compression ratio and the clearance volume.
The compression ratio is the ratio of the volume of the gas at the beginning of compression to the volume of the gas at the end of compression. A higher compression ratio increases the efficiency of the compressor because it allows for more work to be done on the gas, resulting in increased pressure and temperature.
The clearance volume is the volume of the space between the piston and the cylinder head when the piston is at top dead center. A smaller clearance volume reduces the amount of gas that is trapped in this space during compression, resulting in less energy wastage and improved compressor efficiency.