| 摘要 |
<p>A plant of refrigeration type and a rotary, positive displacement machine for said plant. The plant comprises said machine having at least one rotor provided with spiral lobes and intervening grooves, a condenser communicating with an outlet port (60) of the compressor through a high pressure channel (14), and an evaporator communicating with an inlet port (58) of the compressor through a low pressure channel (18), a vessel for an intermediate pressure communicating with intermediate port means (40) of the compressor through an intermediate pressure channel (36), said intermediate port means being spaced from as well said inlet port (58) as said outlet port (60), and pressure reduction means for decreasing the high pressure in the condenser to the intermediate pressure in the vessel and to the low pressure in the evaporator, respectively. The plant and machine according to the invention is characterized in selectively adjustable valve means (40) for forming a communication between said intermediate channel (36) and said low pressure channel (18).</p> |
