| 摘要 |
<p>A control system for a refrigeration system having an air-cooled condenser exposed to normal year round ambient temperatures. Head pressure is controlled in response to sensed subcooling of the refrigerant in the liquid line near the entrance to the expansion device, so as to prevent the occurrence of flash gas at the expansion device, while still allowing minimum head pressures so as to improve energy efficiency. In alternate embodiments, additional controls are provided for assuring at least a predetermined minimum pressure differential across the thermostatic expansion valve. In one preferred embodiment a two-bulb sensing technique is used for subcooling and pressure differential sensing. Both series and parallel condenser-receiver connection systems are disclosed, as are a number of different subcooling sensing and control embodiments.</p> |
