초록 ▼

A turbocompressor's Surge Limit Line, displayed in coordinates of reduced flow rate (q.sub.r) and reduced head (h.sub.r), can be difficult to characterize if the slope of the line is small; that is, nearly horizontal. And it can be especially difficult to characterize if the surge line exhibits a lo

A turbocompressor's Surge Limit Line, displayed in coordinates of reduced flow rate (q.sub.r) and reduced head (h.sub.r), can be difficult to characterize if the slope of the line is small; that is, nearly horizontal. And it can be especially difficult to characterize if the surge line exhibits a local maximum or minimum, or both. This is often the case with axial compressors having adjustable inlet guide vanes, and for centrifugal compressors with variable inlet guide vanes and diffuser vanes. With their prime objective being the prevention of surge-induced compressor damage and process upsets, antisurge control algorithms should compensate for variations in suction conditions by calculating both the operating point and the Surge Limit Line, utilizing specific (invariant) coordinates derived by using the notations of similitude or dimensional analysis. The result is that the surge limit is invariant (stationary) to suction conditions. This disclosure describes a new method of antisurge control for turbocompressors, which uses combinations of invariant coordinates that differ from those revealed in the prior art. Subsequently, the key to this invention is that any combination (linear or nonlinear) of invariant coordinates is also invariant.

대표청구항 ▼

[ I claim:] [1.] A method of protecting a turbocompressor from surge, the method comprising the steps of:(a) determining a surge line associated with the turbocompressor as a function of a quantity, R.sub.c.sup.m q.sub.r.sup.n ;(b) determining an operating point of the turbocompressor as a function

[ I claim:] [1.] A method of protecting a turbocompressor from surge, the method comprising the steps of:(a) determining a surge line associated with the turbocompressor as a function of a quantity, R.sub.c.sup.m q.sub.r.sup.n ;(b) determining an operating point of the turbocompressor as a function of the quantity R.sub.c.sup.m q.sub.r.sup.n ;(c) comparing the turbocompressor's operating point to the surge line; and(d) modulating an end control element associated with the turbocompressor, based on the comparison, to protect the turbocompressor from surge.