| Laminar condensation particle counter(LCPC)is a detection instrument used to measure nanometer and submicron particles in gas.LCPC generates heterogeneous nucleation of particles by creating a supersaturated environment,and then uses optical detection to detect and count the grown particles.In this paper,the key component of the laminar condensate particle counter,the particle growth device,are mainly studied by numerical simulation,and the growth process of nano-carbon particles in the flow field of the particle growth device is simulated.(1)The conditions for the heterogeneous nucleation of particles as condensed nuclei in LCPC were studied,and the performance differences and characteristics of different particle growth media were compared.(2)The mass and heat diffusion process in the LCPC particle growth device was studied,combined with the characteristics of the particle growth device creating a supersaturated environment,the flow field model of the particle growth device was designed,and the model was numerically simulated.,studying the effect of boundary condition changes on the supersaturation distribution in the condensation section.(3)Selecting water as the particle growth medium,and taking carbon particles as the research object,a theoretical model for the growth of submicron and nano-scale carbon particles was established,and secondary development was carried out on the basis of the discrete phase model,so that it had the ability to The ability to simulate the heterogeneous nucleation process of nanoscale carbon particles in a water vapor supersaturated environment.(4)Using the discrete phase model after secondary development to simulate the growth process and movement trajectory of carbon particles in the particle growth device,the influence of boundary conditions on the movement trajectory of carbon particles in the flow field was studied,and the method of controlling the movement trajectory of carbon particles was obtained..(5)According to the internal flow field model of the LCPC particle growth device,the LCPC prototype was designed and processed,and the appropriate supporting devices were selected to build the experimental device,which realized the expected gas and liquid circulation functions,the prototype was used for experiments to confirm its rationality. |
