超临界压力下600 MW直流锅炉水冷壁管阻力特性的试验研究

Experimental Study on Frictional Flow Resistance in Water Wall Tubes of A 600 MW Supercritical Once-Through Boiler

研究国产600MW直流锅炉水冷壁管在超临界压力下的摩擦阻力特性.试验段为φ25×3mm的1Cr18Ni9Ti不锈钢管,试验参数为:压力p=23～25 MPa,质量流量G=400～1200kg/(m2·s),工质比焓h=600～2600kJ/kg,雷诺数Re=1.2×104～1.0×106.试验研究了工质压力、质量流速、工质比焓(工质温度)和雷诺数对摩擦阻力系数的影响.试验发现:在相变点附近,摩擦阻力系数有一阶跃增加,而且随着压力的增加,摩擦阻力系数在相变点的阶跃增加现象变弱.由试验数据得到超临界压力下水冷壁管摩擦阻力系数的经验关联式,计算值与试验值的相对误差在10%以内.

Characteristics of frictional flow resistance of water wall tubes of a domestic manufactured 600 MW supereritical once-through boiler have been studied. Tests were performed with a φ = 25 × 3 mm tube section, made of stainless steel 1 Cr18 Ni9Ti, in the following parameter ranges ： pressure p = 23-25 MPa, mass flow G = 400-1200 kg/（ m^2 · s）, specific enthalpy of working medium h = 600-2600 kj/kg and Reynolds number Re = 1.2 × 10^4-1.0 × 10^6. Influences of the above parameters （including the medium＇ s temperature） on the friction coefficient were investigated. Test results show that the friction coefficient incurres a step jump on passing the phase change point, abating with rising pressure. Based on the test data, an empirical formulas is obtained for calculating friction coefficients of water wall tubes, under supereritical pressure conditions, with a possible error below 10% compared with experimental measurements. Figs 7 and refs 4.