초록 ▼

A process and a computer implemented system for controlling an axial compressor through measurement of pressure fluctuations of the turbulent fluid layer in the region of the compressor housing in at least one stage of the compressor by means of at least one pressure sensing device sensitive to diff

A process and a computer implemented system for controlling an axial compressor through measurement of pressure fluctuations of the turbulent fluid layer in the region of the compressor housing in at least one stage of the compressor by means of at least one pressure sensing device sensitive to differential pressure fluctuations affecting the blades at the characteristic frequency of the stage. The process and computer implemented system use a characteristic peak which emerges under load in a smoothed frequency signal derived from a transform of the pressure measurement to achieve optimal efficiency while, at the same time, avoiding destructive surge and stall conditions in the compressor.

대표청구항 ▼

Process for controlling an axial compressor, said axial compressor comprising: a rotor, a housing, an inlet where, in operation, gas enters at a first pressure, and an outlet where, in operation, gas exits at a second pressure higher than said first pressure, said rotor being rotatably mounted withi

Process for controlling an axial compressor, said axial compressor comprising: a rotor, a housing, an inlet where, in operation, gas enters at a first pressure, and an outlet where, in operation, gas exits at a second pressure higher than said first pressure, said rotor being rotatably mounted within said housing for rotation about a rotational axis, said axial compressor further comprising at least one axial compressor stage, each said axial compressor stage comprising: a row of rotor blades mounted on said rotor and being arranged one following the other in a circumferential direction with respect to said rotational axis, and a row of stator blades mounted on said housing and being arranged one following the other in a circumferential direction with respect to said rotational axis, each said axial compressor stage having, in operation, a turbulent fluid layer surrounding each said rotor in the region of said housing, each said axial compressor stage further having, in operation, a characteristic frequency defined as the product of the number of rotor blades mounted in said row of rotor blades and the rotational speed of said rotor, each said characteristic frequency having an associated frequency interval contiguous above and below said characteristic frequency, said process comprising the following steps: controlling said axial compressor to a first load level and known rotational speed such that the first load level is sufficiently low in value to avoid the risk of surge and stall conditions in said axial compressor; measuring the pressure fluctuations of at least one said turbulent fluid layer with a pressure sensing means responsive at the characteristic frequency for the known rotational speed and generating thereby at least one sensor signal; deriving a plurality of frequency components within the frequency interval from each sensor signal, wherein one of the plurality of frequency components is derived at a frequency essentially equivalent to said characteristic frequency; smoothing said plurality of frequency components into a frequency signal; respective to the above steps, incrementally increasing the load on said axial compressor at said known rotational speed and performing the steps of measuring each resultant sensor signal, deriving respective resultant frequency components, and smoothing said respective resultant frequency components into a respective resultant frequency signal at each resulting load increment until at least one first characteristic peak is defined in a respective resultant frequency signal, said first characteristic peak having a frequency range proximate to said frequency interval and a mean frequency essentially equal to said characteristic frequency, and each said first characteristic peak further having at least one first peak parameter respective to those portions of the respective resultant frequency signal which are not a part of any said first characteristic peak; retaining the value of said first peak parameter; respective to the above steps, further incrementally increasing the load on said axial compressor at said known rotational speed and performing the steps of measuring at least one resultant sensor signal, deriving respective resultant frequency components, and smoothing said respective resultant frequency components into a respective resultant frequency signal at the resulting load increment to define at least one second characteristic peak, said second characteristic peak having a frequency range proximate to said frequency interval and a mean frequency essentially equal to said characteristic frequency, and each said second characteristic peak further having at least one second peak parameter respective to that portion of the frequency signal which is not a part of any said second characteristic peak; comparing the value of said second peak parameter with the value of said first peak parameter; incrementally modifying the load on said axial compressor at said known rotational speed to a higher level if the value of said second peak parameter is greater than or equal to the value of said first peak parameter, and to a lower level if the value of said second peak parameter is less than the value of said first peak parameter, and respective to the above steps, perpetually repeating the steps of measuring a subsequent sensor signal, deriving respective subsequent frequency components, smoothing said respective subsequent frequency components into a subsequent frequency signal, comparing a subsequent peak parameter value with its respective prior peak parameter value, retaining each peak parameter value as the prior peak parameter value for the subsequent comparing step, and incrementally modifying the load on said axial compressor on a periodic basis to, in each case, increase the load on said axial compressor at said known rotational speed to a higher level if the value of a peak parameter is greater than or equal to the value of its respective prior peak parameter, and decrease the load on said axial compressor to a lower level if the value of a peak parameter is less than the value of its respective prior peak parameter.