A Test Platform Of Steam-water Pipe Network And Fittings For Hydraulic-thermal Characteristics Research

Steam-water pipe network including many pipes and accessories is an important part ofthe steam power system, which is connected to the boiler, steam turbine, heat exchangers andother thermal equipments. All thermal equipment of the steam power system must beconnected with the Steam-water pipe network, so its hydraulic characteristics and thermalcharacteristics directly affect the performances of the whole system. Steam can producepressure drop and heat loss in the process of transmission, which can cause thermal andhydraulic loss and even make the terminal equipments of pressure, temperature, flow andother parameters can not meet the requirements. Duing to the thermal and hydraulic loss, itreduces the efficiency, wastes of energy and even can’t be used normally, the effectiveanalysis of hydraulic and thermal performances of steam-water pipe network has an extremelyimportant significance.In this paper, standard k turbulence model was used to simulate the straight pipehydraulic-thermal characteristics with the software of Fluent, and RNG turbulence model wasused to simulate the hydraulic-thermal characteristics of the local resistance elements(including sudden expansion pipe, sudden contraction pipe,90°elbow, orifice plates, gatevalve, cut-off valve and ball valve). In order to accurately reflect the change of superheatedsteam state parameters, the NIST Real Gas Model was used. At the same time, a steampipeline experiment table was built, then the hydraulic-thermal characteristics of thesuperheated steam pipe network were studied, and the corresponding experimental conditionsof steam pipe network were simulated. Compared the numerical results with experimentaldata, it obtained the steam pipe network hydraulic-thermal characteristics.The numerical results show that, error between straight pipe hydraulic loss, thermal lossand the theoretical calculation value of is within5%; for resistance element, the main reasonof affecting its resistance loss is the geometric dimension, but when the geometry dimensionis determined, its drag coefficient varies with the change of flow rate and diameter, which haslarger deviation with experience and empirical formula. Therefore, the local resistancecoefficient is also related to the velocity and pipe diameter. Experimental study and numericalsimulation of steam pipe network show that experimental data have a good agreement withthe simulation results, the steam pipe network hydraulic and thermal characteristics are related to the velocity, which verifies the accuracy of numerical simulation results and provides atheoretical basis for the hydraulic and thermal steam-water pipe network.