METHOD TO DETERMINE INTERFACE LEVEL IN CHANNELS Russian patent published in 2014 - IPC G01F23/24 

FIELD: measurement equipment.

SUBSTANCE: invention relates to measurement equipment and may be used to determine interface in steam generating plants. The method consists in the fact that a sensor is installed, made, for instance, in the form of an electroconductive wire, in a channel along with gravity, the sensor is heated by sending current via the sensor, electric resistance of the sensor R is measured, differing by the fact that the current I, passing through the sensor, is measured, the sensor temperature increment is determined in sections of the sensor that contact with steam and liquid phases Δt_s=I²R/πdLα_s, Δt_l=I²R/πdLα_l, they determine specific electric resistance of the sensor that contacts with the steam and liquid phases ρ_s=ρ₀(1+βΔt_s), ρ_l=ρ₀(1+βΔt_l), they determine thickness of steam h_s and liquid layer h_l:h_s=(RS-ρ_lL)/(ρ_s-ρ_l)₎ h_l=L-h_s, where ρ_l and ρ_s - specific electric resistance of the sensor, which is in the liquid ρ_l and the steam phase, accordingly; R - electric resistance of the sensor; I - current through the sensor; L - length of the sensor; S - cross section of the sensor, β - thermal coefficient of resistance, d - diameter of the sensor, ρ₀ - specific electric resistance of sensor material at t=20°C, α_s, α_l - heat emission coefficients on the surface of the sensor when interacting with steam and liquid phases. If there is a double-phase layer is present in the channel, additionally an additional sensor is installed in the form of an electroconductive wire in the channel cross section, where the double-phase layer is not present.

EFFECT: higher accuracy of determination of interface levels of steam, liquid phases and double-phase layer.

2 cl, 2 dwg