초록 ▼

A method is disclosed for efficiently protecting dynamic compressors from surge under changing inlet conditions and in response to flow disturbances of varying size and speed. An antisurge control system based on this disclosed method will compute the relative proximity of the compressor operating p

A method is disclosed for efficiently protecting dynamic compressors from surge under changing inlet conditions and in response to flow disturbances of varying size and speed. An antisurge control system based on this disclosed method will compute the relative proximity of the compressor operating point to its surge limit as a multi-variable parameter which is self-compensated for changes in gas composition, inlet temperature and pressure, compressor efficiency, guide-vane position, and rotational speed. A combination of adaptive closed- and open-loop control responses is used to maintain a margin of safety between the operating point and the surge limit. Both the safety margin and the magnitude of the open-loop response are proportional to the rate at which the operating point approaches the surge limit, thus maximizing process efficiency.

대표청구항 ▼

A method of anti-surge protection for a dynamic compressor having a corresponding compressor performance map and inlet and discharge networks, an anti-surge valve connecting said discharge and inlet networks and an anti-surge control system operating said anti-surge control valve to maintain the rel

A method of anti-surge protection for a dynamic compressor having a corresponding compressor performance map and inlet and discharge networks, an anti-surge valve connecting said discharge and inlet networks and an anti-surge control system operating said anti-surge control valve to maintain the relative distance between the compressor operating point and the surge limit below which said compressor would surge, said relative distance being a difference between the relative operating slope of the compressor and the relative slope of the surge limit, both of said relative slopes being ratios of the actual slopes to the slope of the surge limit line, both actual slopes being tangents of the angles between the operating point and the horizontal axis of the compressor performance map and the surge limit and the horizontal axis of the compressor performance map, said method comprising: continuously calculating said relative distance between the compressor operating point and the surge limit as a function of one or more measured process variables and adjusting the position of said anti-surge valve by a closed loop response of the control system to prevent said relative distance between the compressor operating point and the surge limit from decreasing below a minimum margin of safety, said margin of safety including both constant and variable parts; and maintaining said variable part at zero under steady-state conditions, increasing said variable part when said operating point approaches said surge limit at an increasing rate, and slowly decreasing said variable part toward zero when the rate of approaching surge decreases.