Pressure relief unit - compressor as a replacement of a throttle valve of a two - two-phase flow

摘要

A positive displacement machine (30) having a set of parallel meshing rotors (32,34) employed in a compression-expansion refrigeration system receives a fluid refrigerant input from a condenser (13) and expands the fluid in a first zone and forces substantially all of the liquid in the first zone to an evaporator (15). The remaining fluid from the first zone of the machine (30) is then compressed in an adjacent second zone of the machine (30) to form a high pressure vapor, which is then routed back to the condenser (13). The positive displacement machine (30) includes a first rotor (32) having a plurality of helical lobes (42) disposed about a rotor periphery. At least one second rotor (34) has a plurality of helical grooves (46) disposed about a second rotor periphery for receiving the lobes (42) of the first rotor (32) during rotation of the rotors in opposite directions. A housing (36) defines a chamber for enclosing the rotors (32,34). The plural displacement machine (30) includes an inlet port (56) at one end, an outlet port (60) at an opposing end, and an intermediate port (58) in a side wall of the chamber between the inlet and outlet ports (56,60). An effectively closed expanding working chamber (52) is formed between the inlet and intermediate ports (56,58), while an effectively closed contracting working chamber (54) is formed between the intermediate and outlet ports (58,60). IMAGE