Research On Flow Field Character And Engineering Application Of Supersonic Separator With Inner Pyramid

There are gas liquid hydrocarbon and water in nature gas from well head.Dewatering and deliquid hydrocarbon is a necessary step in nature gas production.In recent years, the Supersonic Gas Separation (SGS) Technology for gas mixture separation has attracted great attention.It gets expansion, gas/liquid separation function together and whole the separation prosess is completed in closed and compact equipment.Compared with conventional technology,such as solvent absorption,solid adsorption, low temperature separation, and membrane separation, it has advantages including simple structure, small occupied space, low energy consumption and investment cost, and high iso-entropic efficiency etc.To enhance the application value of SGS and reduce the energy consumption, a novel SGS device with ring-section supersonic nozzle has been designed. An Eulerian two-fluid model for the spontaneous condensing flow of gas mixture has been set up and it is used to predict the feasibility and the factor influences of SGS device. Besides,a method to improve the device separation performance has been put forword,and series of simulations and experiments are carried out to study the separation performance of the designed SGS device and validate the mentioned method.Based on the study of swirl generator,supersonic nozzle and diffuser, a novel SGS device with ring-section supersonic nozzle is designed. Comparing with the traditional supersonic nozzle with circular section, the supersonic nozzle with ring section has the advantages including easy to machining, low pressure loss and short settlement distance for droplets.By adjusting the structure size of supersonic nozzle and diffuser,the SGS can work at low pressure ratio.Therefor,the industrial application of SGS is greatly enhanced.Besides, in virtue of the established Eulerian two-fluid model,two entire devices with different export structure are simulated.It is found that different export structures should be used in different situations.To improve the SGS device's separation performance, the method of adding nucleation center is adopted.The experiment platform is established to study the separation performance of SGS Device with Inner-Pyramid and validate the method used to improve the performance of SGS.The experimental medium is air-ethanol steam mixture and the are or Experimental results shows that the separation performance of the equipment is remarkably improved by using the droplet enlargement method.Under the pressure ratio of 1.75,when the external condensation nucleuses are micro water drops, the maximums of the heavy component removal rate and the dew point depression are 47.10% and 18.55K, increased by 28.08% and 9.8K respectively in comparison with no external condensation nucleuses.when using sodium bicarbonate solution drops, the removal rate and dew point depression can reach 52.05% and 20.4K, increased by 33.03% and 9.8K respectively.Based on the actual condition of Dehydration and De-hydrocarbon of Natural Gas in Tarim oilfield,the SGS device which can be used in practice is designed.Besides,in virtue of the commercial software FLUENT, the device is simulated with methane of real property.The simulated result shows that the designed SGS is possessd of industrial application value.