CRYOGENIC COMPRESSION OF NATURAL GAS

Abstract

Decrease of intake gas temperature of the compressor reduces the compression work. For low temperature compression the cooling by refrigerating machine which consumes additional energy is necessary. Consideration of the idealized processes has shown, that total consumption of energy, as a rule, increases, but in the some cases exist the economy not exceeding 5…7 %. Versions of use of gas pressure in the main pipeline with his expansion in the turboexpander surveyed. If work of expansion is transferred directly to the compressor then at pressure in a intake 2...7 MPa can be compressed up to 25 MPa from 20 to 130 % of gas (concerning his charges through the turboexpander). The cold stream from the turboexpander chills intake gas of the compressor and reduces compression work. If to carry out liquefaction in expansion cycle, compression occurs by the pump which work makes 6-20 % of direct compression. Conditions of serviceability of a cycle are investigated at pressure of the gas equal to 3,5 MPa. Effect of temperature of turboexpander incoming flow is investigated. The restrictions superimposed by a heat exchange in heat exchangers are determined. The optimal temperature in front of the turboexpander has find and the compressed stream in relation to expansion flow has made 36 %.