Integrated moist steam flow dryness measuring device and measuring method

An integrated moist steam flow dryness measuring device comprises a double-Venturi tube. The double-Venturi tube is composed of an input Venturi tube and an output Venturi tube which are connected in series, the diameter of a port of the input Venturi tube is equal to the diameter of a port of the output Venturi tube but the diameter ratio of the throat part of the input Venturi tube is not equal to the diameter ratio of the throat part of the output Venturi tube. The input Venturi tube and the output Venturi tube are connected with differential pressure measuring devices for measuring the differential pressure of the throat parts of the input Venturi tube and the output Venturi tube. The input Venturi tube is further connected with a pressure measuring device used for measuring the pressure of a pipeline of the input Venturi tube. Preferably, each differential pressure measuring device comprises a condenser and a pressure difference transmitter, wherein the condenser is connected with a throat pipeline of the corresponding Venturi tube, and the pressure difference transmitter is connected with a pipeline of the condenser. By means of the integrated moist steam flow dryness measuring device, the total flow and dryness of the moist can be calculated on line in real time due to the fact that the two Venturi tubes with different structures are connected in series.