Refrigeration compression system using two compressors

Abstract

Apparatus for compressing gaseous refrigerant for use in a refrigeration circuit of a liquefaction plant comprises a refrigeration circuit ( 1 ) and two compressors ( 10, 20 ) that are functionally connected to the refrigeration circuit. One of the compressors is provided with a double suction configuration, and the outlets and the inlets of the first and second compressors are connected at least partly in a mutually parallel flow configuration such that the refrigerant flow that leaves the refrigeration circuit from a plurality of outlets thereof is distributed between the two compressors before joining at the inlet of the refrigeration circuit.

1 . Apparatus for compressing gaseous refrigerant for use in a refrigeration circuit of a liquefaction plant, the apparatus comprising:
 a refrigeration circuit including an inlet for refrigerant at a refrigeration pressure, a low pressure outlet for gaseous refrigerant at a low pressure, a high pressure outlet for gaseous refrigerant at a high pressure and at least one intermediate pressure outlet for gaseous refrigerant at an intermediate pressure;   a first compressor received in a first casing and provided with a double suction configuration including at least two main inlets and one outlet;   a second compressor received in a second casing separate from the first casing and having an at least one inlet and an outlet, the outlet of the second compressor being connected to the inlet of the refrigeration circuit; and   a common power source including an output shaft for driving the first and second compressors;   wherein the first and second compressors are provided with inlets and outlets that are functionally connected to the inlet and the outlets of the refrigeration circuit, and the outlets and the inlets of the first and second compressors are connected at least partly in a mutually parallel flow configuration.   
     
     
         2 . The apparatus according to  claim 1 , wherein the two main inlets of the first compressor are commonly connected in a symmetric configuration. 
     
     
         3 . The apparatus according to  claim 2 , wherein the two main inlets of the first compressor are connected to the low pressure outlet of the refrigeration circuit. 
     
     
         4 . The apparatus according to  claim 3 , wherein the first compressor is further provided with a pair of side inlets in a symmetric configuration that are connected to the intermediate pressure outlet of the refrigeration circuit. 
     
     
         5 . The apparatus according to  claim 2 , wherein the two main inlets of the first compressor are connected to the intermediate pressure outlet of the refrigeration circuit. 
     
     
         6 . The apparatus according to  claim 1 , wherein the two main inlets of the first compressor are connected to different outlets of the refrigeration circuit. 
     
     
         7 . The apparatus according to  claim 1 , wherein the second compressor is provided with a straight suction configuration. 
     
     
         8 . The apparatus according to  claim 7 , wherein the outlet of the second compressor is connected to the inlet of the refrigeration circuit via an economizer. 
     
     
         9 . The apparatus according to  claim 1 , wherein the second compressor is provided with a double suction configuration. 
     
     
         10 . The apparatus according to  claim 1 , wherein the outlet of the first compressor is connected to the inlet of the refrigeration circuit. 
     
     
         11 . The apparatus according to  claim 1 , wherein the outlet of the first compressor is connected to a side inlet of the second compressor. 
     
     
         12 . The apparatus according to  claim 1 , wherein the refrigeration circuit comprises two intermediate pressure outlets for gaseous refrigerant at intermediate pressures.