Method of regulation that prevents surge in a turbocompressor by initiating blow-off when necessary

Claim 2

A regulating method for preventing surges in a turbocompressor by initiating blow-of when necessary, comprising the steps: measuring continuously flow to a turbocompressor and the compressor outlet pressure; calculating a first regulating difference from said measuring step; forwarding said first regulating difference as an input parameter to a regulator having a limited response rate; supplying an output of said regulator as a regulating parameter to a blow-off valve; opening rapidly said blow-off valve by safety controls under malfunctioning conditions that stress the limited response rate of said regulator; calculating a second regulating difference from said measuring step or from said first regulating difference for indicating need to open rapidly said blow-off valve, calculating said second regulating difference being carried out with predetermined reference values; supplying the calculated second regulating difference to a threshold stage emitting a rapid-opening parameter when said second regulating difference exceeds a predetermined threshold stored in said threshold stage; forwarding said rapid-opening parameter to said regulator; and generating by additive superposition in said regulator an accelerated change in a valve-adjustment parameter for activating said valve in opening direction to protect the turbocompressor against occurrence of pressure surges, said regulator being a proportional-integral component; supplying only said first regulating difference to said proportional component; and supplying the sum of said first regulating difference and said rapid-opening parameter to said integral component.

Claim 3

A method as defined in claim 1, including the step of passing said sum of said first regulating difference and said rapid-opening parameter through a limiter before entering said integral component of said proportional-integral regulator.

Claim 4

A regulating method for preventing surges in a turbocompressor by initiating blow-off when necessary, comprising the steps: measuring continuously flow to a turbocompressor and the compressor outlet pressure; calculating a first regulating difference from said measuring step; forwarding said first regulating difference as an input parameter to a regulator having a limited response rate; supplying an output of said regulator as a regulating parameter to a blow-off valve; opening rapidly said blow-off valve by safety controls under malfunctioning conditions that stress the limited response rate of said regulator; calculating a second regulating difference from said measuring step or from said first regulating difference for indicating need to open rapidly said blow-off valve, calculating said second regulating difference being carried out with predetermined reference values; supplying the calculated second regulating difference to a threshold stage emitting a rapid-opening parameter when said second regulating difference exceeds a predetermined threshold stored in said threshold stage; forwarding said rapid-opening parameter to said regulator; and generating by additive superposition in said regulator an accelerated change in a valve-adjustment parameter for activating said valve in opening direction to protect the turbocompressor against occurrence of pressure surges, said regulator being a proportional-integral regulator having an integrator as an integral component with two input terminals, integrating through one of said input terminals by a procedure that is independent of the other input terminal, supplying said first regulating difference to said other input terminal, and supplying said rapid-opening parameter to said first input terminal.

Claim 5

A regulating method for preventing surges in a turbocompressor by initiating blow-off when necessary, comprising the steps: measuring continuously flow to a turbocompressor and the compressor outlet pressure; calculating a first regulating difference from said measuring step; forwarding said first regulating difference as an input parameter to a regulator having a limited response rate; supplying an output of said regulator as a regulating parameter to a blow-off valve; opening rapidly said blow-off valve by safety controls under malfunctioning conditions that stress the limited response rate of said regulator; calculating a second regulating difference from said measuring step or from said first regulating difference for indicating need to open rapidly said blow-off valve, calculating said second regulating difference being carried out with predetermined reference values; supplying the calculated second regulating difference to a threshold stage emitting a rapid-opening parameter when said second regulating difference exceeds a predetermined threshold stored in said threshold stage; forwarding said rapid-opening parameter to said regulator; and generating by additive superposition in said regulator an accelerated change in a valve-adjustment parameter for activating said valve in opening direction to protect the turbocompressor against occurrence of pressure surges, said regulator being a proportional-integral regulator having an integrator as an integral component with two input terminals, integrating through one of said input terminals by a procedure that is independent of the other input terminal, supplying said first regulating difference to said other input terminal, and supplying said rapid-opening parameter to said first input terminal.

Claim 6

A method as defined in claim 3, including the step of assigning different integration time constants to said two input terminals of said integral component.

Claim 7

A regulating method for preventing surges in a turbocompressor by initiating blow-off when necessary, comprising the steps: measuring continuously flow to a turbocompressor and the compressor outlet pressure; calculating a first regulating difference from said measuring step; forwarding said first regulating difference as an input parameter to a regulator having a limited response rate; supplying an output of said regulator as a regulating parameter to a blow-off valve; opening rapidly said blow-off valve by safety controls under malfunctioning conditions that stress the limited response rate of said regulator; calculating a second regulating difference from said measuring step or from said first regulating difference for indicating need to open rapidly said blow-off valve, calculating said second regulating difference being carried out with predetermined reference values; supplying the calculated second regulating difference to a threshold stage emitting a rapid-opening parameter when said second regulating difference exceeds a predetermined threshold stored in said threshold stage; forwarding said rapid-opening parameter to said regulator; and generating by additive superposition in said regulator an accelerated change in a valve-adjustment parameter for activating said valve in opening direction to protect the turbocompressor against occurrence of pressure surges.

Claim 8

A regulating method for preventing surges in a turbocompressor by initiating blow-off when necessary, comprising the steps: measuring continuously flow to a turbocompressor and the compressor outlet pressure; calculating a first regulating difference from said measuring step; forwarding said first regulating difference as an input parameter to a regulator having a limited response rate; supplying an output of said regulator as a regulating parameter to a blow-off valve; opening rapidly said blow-off valve by safety controls under malfunctioning conditions that stress the limited response rate of said regulator; calculating a second regulating difference from said measuring step or from said first regulating difference for indicating need to open rapidly said blow-off valve, calculating said second regulating difference being carried out with predetermined reference values; supplying the calculated second regulating difference to a threshold stage emitting a rapid-opening parameter when said second regulating difference exceeds a predetermined threshold stored in said threshold stage; forwarding said rapid-opening parameter to said regulator; and generating by additive superposition in said regulator an accelerated change in a valve-adjustment parameter for activating said valve in opening direction to protect the turbocompressor against occurrence of pressure surges.

Claim 9

A method as defined in claim 5, wherein said compressor has an operating point with actual speed in its performance field; calculating said actual speed from said first regulating difference representing the position of said operating point in said field; calculating said second regulating difference from the difference between said actual speed and a reference speed associated spatially with said actual speed in accordance with a predetermined position-speed function that will just prevent surging when said operating point arrives at said function.

Claim 10

A method as defined in claim 5, wherein said rapid-opening parameter is a function that increases and decreases in accordance with time.

Claim 11

A method as defined in claim 5, including the step of forwarding said rapid-opening parameter to an output terminal of said regulator; and adding said rapid-opening parameter with its mathematical sign modified to said valve-adjustment parameter output by said regulator.

Claim 12

A method as defined in claim 5, including the step of adjusting an output of said regulator to a level corresponding to the actual state of said blow-off valve while said rapid-opening parameter is being emitted by said threshold stage.