Experimental investigation of transient heat transfer in the once-through boiler water separator

Abstract

The transient heat transfer between working fluid and inner wall of 600 MW supercritical pressure boiler’s water separator model during start-up was experimentally explored. The test conditions for water steam two-phase were as follows: pressure P=3–11 MPa, mass flow M=0.2–0.35 kg/s, and mass quality x=0.2–0.8; for subcooled water P=3–11 MPa, M=0.2–0.35 kg/s, and subcooled degree Δθ=10°C. By using an accurate and tractable inverse heat conduction solution, the correlations of single-phase and two-phase transient heat transfer coefficients were obtained. The experimental results demonstrated the heat transfer enhanced for subcooled water and water steam mixture compared with fully developed turbulent flow in tube. The increasing heat transfer effect may be attributed to the deformation or destruction of the boundary layer.