| 摘要 |
<p>A self-optimizing, capacity control system for a refrigeration system including a compressor (20), a condenser (22), and an evaporator (28), all connected in a closed refrigeration circuit is provided. The compressor includes a plurality of adjustable inlet guide vanes (31), a motor (32) connected to regulate the inlet guide vanes position and an electrical speed motor (36) connected to drive the compressor. The self-optimizing capacity control system includes a microprocessor (106) responsive to continual measurements ofa PRV signal, a compressor head signal, a motor current signal and a motor speed signal for determining both the compressor speed and the position of the inlet guide vanes to define a current operating point in an initial surge surface array stored in a random-access memory (107). The microprocessor will initiate a "learning" mode in which the compressor motor speed will continually be decreased incrementally and the PRV will be moved to a more open position until an operating point is found where the compressor is surging. The microprocessor will update the initial surge surface array stored in the random-access memory with the latest surge conditions. Then, the microprocessor will initiate an "operating" mode in which the PRV are moved to a position responsive to a temperature error signal related to the difference between the chilled water temperature and the temperature set point and the compressor speed is set a safety margin away from the surge speed. In this manner, the microprocessor automatically regulates both the adjustable inlet guide vanes and the compressor speed in response to the continually updated "learned" chiller surge surface so as to realize minimum overall chiller energy consumption.</p> |
