A Study On Steam Injection Boiler's Super Heater By Using Multi-field Coupling Numerical Simulation Method

Currently,the steam injection boiler in oil field has become one of the core equipments for heat production,but it works in high temperature and high pressure conditions,so the safe and efficient operation is the key to heavy oil exploitation.Superheater is in the high temperature zone inside the steam injection boiler,there is high temperature steam internal the pipeline and high temperature flue gas external the pipeline,and the internal and external outflow are both complex turbulent flow.As it's very hard to measure the temperature distribution of each part with the current technology,the method of numerical simulation is adopted to make prediction to the superheater performance.Based on the working principals of steam boiler,I demonstrate the characteristics of its working condition and environment.This paper aims to choose a reasonable mathematical model for calculations including:fundamental equations of flow&heat transfer,and finally to select optimal turbulence model and radiation model.Make comprehensive 3D numerical simulation to the superheater by CFD software,and get the distribution regularity of flow field and temperature field of the superheater.It is shown from the simulation result that,because of the influence of structure in the side wall,the flue gas flows away near the tube plate,and the speed achieves maximum value here.Under different conditions,with the increase of load,the maximum value of flue gas velocity presents incremental trend.The flue gas in the mainstream area is tending to stability in thfourth row.The wall temperature inside and outside the pipe both increases along the flow direction,and the outer wall temperature is slightly higher than that in the inner wall.Through the ANSYS CFX-POST,both temperature and pressure field simulated in FLUENT were accurately mapped to ANSYS structure model to analyze the heat exchanger's bundle with multi-field coupling method,both equivalent stress and displacement distribution of heat exchanger's bundle was determined,and to evaluate heat exchanger's strength.