In this paper,calculation formulas which used in three Kinds of references for criti- cal velocity of a vertical helical conveyor are analysed and compared.

Diagnosis of vertical helicity, divergence flux and their extensions in heavy-rainfall events

The results show that the centers of rainstorm are in the high value area of convective available potential energy and vertical helicity,and in the high value area of isentropic potential vorticity on 325 K.

The mechanism analysis of a flood-inducing heavy rainfall occurred in June 2005 Guangdong Province is diagnosed by analyzing the circulation situation,moisture,dynamical mechanism,vertical helicity,and so on based on the conventional observation data,radar echo,satellite image and NCEP grid data.

Using super absorption polymer mixed with the original soil as backfilled material, explores the performance of the ground-source heat pump system with spiral coil and U-shaped coil as underground heat exchanger respectively by experiment and obtains the performance curves.

In heat model,spiral coil ground heat exchanger(GHE)and U-shaped GHE were tested,respectively.

Effect of additive on thermal energy stored and discharged performance of wax phase change thermal storage with spiral pipe;