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Antisurge control/valves

The essence of surge protection is determining when and how much to open or close the recycle valve. In the simple application of Figure 6-45, the antisurge controller (UIC) will position the recycle valve using a control algorithm based on AP, AP, and data on the location of the surge limit. [Pg.392]

The first objective of the antisurge control system is to protect the compressor. This can be accomplished for some disturbances by using the PI algorithm with a large value of bj. However, it is also necessary to maximize the region in which the compressor can operate with the recycle valve closed. This increases the efficiency of the compressor at lower throughputs. Steady-state operation with recycle is extremely inefficient. Therefore, from this perspective, small values of bj are highly desirable. [Pg.394]

Control valves form an important equipment item in process plants, and therefore, a lot of money can be saved by ensuring that the right valves are installed. Selecting the right control valve for any application starts with defining the valve s functions. For example, if an on-off interlock valve is to be used, then the primary criteria for selection are reliability and simplicity. If very fast and precise modulation is required, such as for a compressor antisurge vent, a high quality valve is chosen. [Pg.345]

In addition to antisurge control, it is common to have a surge recovery scheme. This relies on the detection of rapid changes in pressure or flow and then overrides the antismge scheme to fully open the recycle valve. It can also increase the safety margin used by the antisurge controller so that, when the antisurge scheme is permitted to take back control, the same situation should not recur. [Pg.257]

The antisurge controller will interact with other schemes on the compressor. For example, it opening the recycle valve will cause the discharge pressure to drop and hence also the flow to the downstream process. The flow (or pressure) controller will then to take corrective action. To avoid this interaction propagating this controller should be tuned to act significantly slower than the antisurge scheme. [Pg.257]

A minimum flow controller ( antisurge ) sets the valve in the compressor bypass line to prevent the flow rate through the compressor from dropping below some minimum flow rate. [Pg.290]

INVESTIGATION ON PERFORMANCE OF TURBOCHARGED SPARK-IGNITION ENGINE EQUIPPED WITH ANTISURGE VALVE AND BYPASS FLOW CONTROL MECHANISM AT VARIOUS WORKING CONDITIONS... [Pg.37]

In order to avoid surge occurrence in compressor, axial or radial one, antisurge valve is used usually. Various mechanisms have been presented for these valves which all of them are based on reduction of compressor downstream pressure and according to surge control line (to avoid surge occurrence). We use this line to compensate uncertainly in the measurements and delay in valve performance. There are some descriptions for this parameter that one of them has been shown in Eq. (3.8). [Pg.49]


See other pages where Antisurge control/valves is mentioned: [Pg.124]    [Pg.395]    [Pg.396]    [Pg.434]    [Pg.289]    [Pg.256]    [Pg.189]    [Pg.396]    [Pg.397]    [Pg.115]    [Pg.39]    [Pg.53]    [Pg.57]   
See also in sourсe #XX -- [ Pg.359 , Pg.368 ]




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Antisurge

Antisurge control

Antisurge controller

Antisurge valve

Control valve

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