Research On The Performance Of The Steam Generator Separation Device

As is known to all, cyclone separator is the primary separator in the steam generator,with the advantages of small volume, simple structure, high pressure resistance, high separation efficiency, etc. People have studied a lot of research work on the performance and the structure optimization of cyclone separator in recent years,however the research on the gravity settling of the space,which is upon the cyclone separator, in the steam generator is rarely known by people. At the same time, many people begin to research new structure of the separator to meet the requirement of steam-water separator in the steam generator. This paper has established the geometric model of a new type of steam separator- the two stage cyclone separating device, and has carried out the numerical simulation research on it.Firstly, this paper has set up the geometric model of the gravity settling space of the steam generator, which is based on the construction of the gravity settling space, carried out the numerical calculation, and analyzed the factors that influence efficiency of gravity separation space. There are a certain number of primary cyclone separators at the entrance of the gravity settling space, whose purpose is more accurate to simulate the velocity and the direction of the velocity at the entrance of the gravity space. The results of the numerical simulation on the gravity space show that the separation efficiency of the gravity space increases gradually firstly and then remains the same with the increase of the height of the gravity space.Secondly, the numerical simulation has been carried out about the single-phase and the two-phase flow fields in the two stage cyclone separating device after establishing the model and meshing. In order to compare with the experimental results, air and water under the atmospheric pressure was used to be the fluid medium in the separator during the process of calculation. The model of RNG k-? was used in the simulation of the single-phase. And the pressure field and the velocity field in the two stage cyclone separating device was analyzed. In addition, the study on the separation characteristics of the two stage cyclone separating device by combining the method of the RNG k-? model, the DPM model and the EWF model. At the same time, the motion of the liquid film on the wall of the two stage cyclone separating device was analyzed. The results of the numerical simulation show that: 1)The pressure drop of the two stage cyclone separating device has a linear relation with the square of the inlet velocity; 2) The separation efficiency increases with the increase of inlet velocity; 3) The motion of the wall film does not effect the pressure drop and separation efficiency of the two stage cyclone separating device obviously.Finally, the pressure loss and the separation efficiency of the two stage cyclone separating device was studied at high-pressure situations with numerical method. The influence of the droplet diameter and the different structure on the pressure loss and the separation efficiency was analyzed. Then the simple optimization of the two stage cyclone separating device was accomplished by summarizing the above results.