Antisurge pretection method for centrifugal compressors

Method for individuating the pumping conditions of centrifugal blowers according to the thermodynamic conditions (pressure and temperature) and to the gas composition in inlet, comprising the steps of:

• a) acquisition of the suction pressure (pi), the suction temperature (TI), acquisition of the delivery pressure (p2), the delivery temperature (T2), the flow rate (Q), the revolution number (n) and of information about the chemical composition of the gas mixture in inlet at the blower (1);
• b) calculation of the reduced conditions of the processed gaseous mixture by means of mixing equations;
• c) solution of the state equation of the real gases for the calculation of the thermo-dynamic properties of the gas mixture in the current conditions acquired at the previous point (a).
• d) acquisition of the performance non-dimensional curves of the blower, which express the value of the blower working coefficient and of the polytropic yield of the blower, according to the Mach number in inlet and to the flow rate parameter;
• e) calculation of the blower performance curves which express the value of pressure and temperature in outlet (2, T2) and of the polytropic predominance {Hp) according to the flow rate and. the revolution number, on the basis of said performance non-dimensional curves acquired at point d), and according to the blower inlet parameters acquired at point a)
• f) determination of the pumping points, individuated as maximum points of the blower performance curves which express the value of the pressure in outlet according to the sucked flow rate, and according to the variation of the revolution number.