| 摘要 |
<p>A method and apparatus for protecting a dynamic compressor from surge. The method used is for antisurge control of a controlled object including a dynamic compressor having a discharge port and a suction port, a driver of the compressor, a pipeline connecting the discharge port of the compressor to a user of compressed gas, a quick-acting on-off fluid relief means connected to the pipeline, and a control means for controlling a main controlled parameter, the parameter being one of (a) the mass flow rate of a gas to the user, (b) the discharge pressure of the compressor, (c) the suction pressure of the compressor and (d) the rate of rotation of the compressor. The method includes a combined pair of steps which provides for the protection from surge and at the same time insures the invariability of the main control parameters of pressure, mass flow rate to the user, or the speed of rotation. The second step provides for controlling a larger relief means and provides for antisurge protection in those cases when the first step is not sufficient to protect the compressor from surge. Improved apparatus is also provided for automatically implementing the method. The improvement comprises particularly interconnected parts, namely (i) a three way valve having an actuator; (ii) a pressure differential means having two inputs; (iii) a monitor switch means for receiving the input signals from the pressure differential means; (iv) the three-way valve; (v) an intermediate volume, having two parts; (vi) an on-off cocking throttle means; and (vii) a monitor switch. The simultaneous closing of the onoff fluid relief means and the actuating of the means for changing the flow rate through the compressor being the inte</p> |
