Study on Pressure Loss of Two Phase Flow and Flow Boiling Heat Transfer in Micro Channel

Recently, tight lattice core reactors had been discussed for a high conversion ratio. The minimum gap clearance between rods was ∼ 1 mm in these reactors. Thus, boiling heat transfer in the narrow space became important. In this paper, the pressure loss and the heat transfer characteristics in mini pipes were investigated experimentally. Diameter of the present mini pipes was 0.5 and 0.15mm, respectively. Length of the test pipes channel was 20mm. The test liquid temperature was room-temperature, i.e., 20°C. A range of Reynolds number was 1082<Re<7423. The present experimental results for D = 0.5mm were in good agreement with the conventional correlations of the pressure loss and the heat transfer for turbulent flow. The present experimental data for D = 0.15mm were also similar to value estimated by the conventional correlations for laminar flow. The CHF in the present experimental conditions was about 2×10⁷W/m². The value was higher than that calculated by the conventional correlation, Ivey-Morris equation.