When transporting aerosol particles through pipes, the penetration efficiencies are directly related to the particle distribution in the cross-section and deposition to the walls. In the present study, the moment equations for nano-sized aerosol particles are solved with the Taylor-series expansion moment method by considering the combined effect of Brownian diffusion, turbulent diffusion, particle coagulation and breakage. The distributions of particle number concentration, particle diameter and polydispersity over a range of particle diameters from 50 to 450 nm in the cross-section at the outlet of the pipe are given. The results show that the particle number concentration is distributed non-uniformly along the radial direction, and the particles in the near wall region are diffused to the region near the pipe center and the wall. Particle diameter increases from an initial value at the inlet to the different values depending on the radial position at the outlet. The largest particles are found in the near wall region from which the particle diameters decrease gradually to the pipe center. Smaller particles become more polydisperse at the outlet. Then the penetration efficiencies over a range of Reynolds numbers from 4426 to 8500 and ratios of pipe length to diameter from 375 to 625 are calculated, and some corresponding experiments are carried out. The results show that 65-95% particles flow through the pipe. The penetration efficiencies increase with increasing particle size, while decrease as Reynolds number increases. The longer the residence time of particles in the pipe is, the larger the probability that particles deposit on the wall is, hence the smaller the penetration efficiency is. Finally, the relationship of penetration efficiency and related synthetic parameters is built up, and the expression for the difference in mean particle diameter between the outlet and inlet of the pipe as function of related parameters is derived, based on the numerical and experimental data. (c) 2014 Elsevier Ltd. All rights reserved.