| 摘要 |
<p>The invention relates to a refrigeration system of the air cycle cooling system type, also called reversed Brayton cycle in which the air flows through compressor means (12, 16), heat exchanger means (24) for withdrawal of heat from the compressed air and finally expander means (22) from where it is delivered to perform cooling. According to the invention the system includes heat load means (41) having a large flow resistance, creating a considerable over-pressure at the expander outlet (23). A rotary screw machine is included in the expander means (22) and also in the compressor means (12, 16), which latter screw rotor machine (12) is driven solely by the screw rotor machine (22) of said expander means. A screw rotor machine (16) connected in parallel with the screw rotor machine (12) of said compressor means is driven separately, preferably by a drive engine (19), the rotational speed of which is controlled by pressure sensing means (36) in a conduit between the expander outlet (23) and an inlet to the heat load means (41), and thereby - via said expander means - also drives the velocity of the screw rotor machine (12) of said compressor means. The sytem is particularly intended for cooling the electronic equipment in aircraft when being on the ground.</p> |
