Energy recovery system in a gas compression plant

摘要

A system is described, for recovering energy in a gas compression plant comprising: at least one centrifugal compressor (10) capable of sucking the gas, at a certain inlet pressure, from a suction conduit (14) and of delivering the gas, at a certain outlet pressure that is greater than such an inlet pressure, through a delivery conduit (16); at least one gas recirculation system (A; B) capable of redirecting the gas from the delivery conduit (16) to the suction conduit (14) when the gas flow rate entering into the compressor (10) is below a certain limit value. In the portion of the plant arranged downstream of the compressor (10) at least one turbo-expander (36; 46) and at least one valve (24; 33) are installed in parallel that cooperate with each other and that are controlled by electronic devices (35) so as to protect the compressor (10) and at the same time to produce useful energy during recirculation mode.