Online measurement device and online measurement method of double-pressure difference gas-liquid flow rate

The invention discloses an online measurement device and an online measurement method of double-pressure difference gas-liquid flow rate. The online measurement device comprises a Venturi flowmeter; a gas-liquid pipe is arranged at one end of the Venturi flowmeter; the gas-liquid pipe is connected with a V-cone flowmeter through a connecting flange; a first pressure gauge is arranged at the front end of the Venturi flowmeter; a second pressure gauge is arranged at the throat part of the Venturi flowmeter; a fourth pressure gauge is arranged at the rear end of the V-cone flowmeter; a third pressure gauge is arranged at a position, between the fourth pressure gauge and the connecting flange, on the V-cone flowmeter. During an actual online gas-liquid flow rate measurement process, respective pressure differences of the Venturi flowmeter and the V-cone flowmeter in a pipeline are acquired and are transmitted into a processor; a gas-liquid two-phase flow rate measurement model is established in the processor; respective flow rates of a gas phase and a liquid phase are calculated and outputted according to the measured pressure differences and by combining the physical parameters of the pipeline and a fluid inputted through a human-computer interface; the online measurement device and the online measurement method have high measurement stabilities.