Design And Simulation Optimization Of Flash Evaporator Used In SAGD Thermal Recovery Of Waste Heat Process

SAGD technology has been paid attention for a long time as the new heavy oil thermal recovery process. While the disposal of produced water and recovery of waste heat are two main problems in academics. In this paper, based on site investigation in XinChun oil field, XinJiang province and combination of advanced MVC technology, one method has been put forward which use the flash evaporator as the bridge of two problems. Specifically, use the steam to provide power for T-MVC disposal system, which is obtained by flash evaporating high temperature and high pressure water from the steam separator.Flash evaporator plays an important role in running of whole system. This paper designs a new flash evaporator which has four tangential inlets with jacket by using the conventional designing method and referring to relative standards and theses. What’s more the intensity of the flash evaporator has been checked.In order to know how the flash process works, a UDF program has been written which is fit for FLUENT software. From the simulation the following conclusions can be drawn. The pressure field and velocity field are extremely imbalanced caused by huge pressure drop. A negative pressure area is emerged at the joint of inlet nozzle and inner wall. The maximum speed is about 162.7m/s. All above conditions constitute the unsecure factors. And the flash rate is about 29% lower than the theoretical value. Meanwhile, this paper have discussed the relation of simulated flash rate and flash evaporate pressure and drawn the conclusion that 2-3MPa is the ideal flash evaporate pressure.Combined all the unsecure factors and the simulation results, finite element stress analysis have been made to check the security of the flash evaporator by using ABAQUS software. The stress results as follow: the maximum main stress is about 253 MPa which is more than twice higher than allowable stress, and these areas are located at the joint of nozzle and inner wall and around the hand hole. According to the simulation results some modifications have been made so as to make sure the security of the flash evaporator.