No abstract

An analytical model is developed to study the sealing performance of the mechanical seals with a laser-textured micro-pore face. The pressure distribution between the seal faces at various operation conditions and micro-pore geometry parameters can be obtained from a solution of the Reynolds equation by finite difference method, and then opening force and liquid film stiffness can be calculated. Seal face geometry parameters can be optimized by analyzing regulation of their effect on opening force and liquid film stiffness. Results of parametric study demonstrate that substantial hydrodynamic effect can be produced on the seal face with micro-pores.

A theoretical model has been developed for the mechanical seals with a laser-textured porous seal face. By means of variable dimensionless steps, parametric analysis has been performed to obtain dimensionless liquid film pressure by the finite difference method. Liquid film pressure profiles over the pore column have be achieved by the computer program MATLAB. It is found from calculating results that average liquid film pressure increases with increase of the rotational speed, liquid viscosity and reduction of liquid film thickness. Hydrodynamic effect produced by micro-pores decreases with increase of fluid pressure. In addition, the effect of the pore area density and depth over diameter ratio on the liquid film pressure is very significant. Optimum values of these parameters can maximize the average liquid film pressure.

A small indoor cooling system through cold water circulation is introduced in this paper. The system mainly includes cooling pool, cold water circulation equipment, indoor heat exchanger, temperature measurement equipment and induction controlling equipment. The indoor cooling is achieved by heat transfer between the natural underground water of lower temperature and indoor air of higher temperature, and it is different from the traditional compression refrigeration system in which a great amount of electric energy is consumed while the refrigerant is compressed. Compared with the ordinary air conditioning system, this system has obvious advantages on economy, application potential and energy conservation in rural developing areas.

By using finite element software ANSYS, stress analysis was conducted to the annular sector semicircular cross section vessel which was made up of an annular sector plate, two semicircular plates and a semi-cylindrical with thicknesses of 20mm. The analysis results show that the maximum equivalent stress of the annular sector plate appears in the middle of the plate, and the maximum equivalent stress of the semicircular plate and the semi-cylindrical appear in the inner surface of the connections. The equivalent stress distribution trend of the annular sector plate, semicircular plates and the semi-cylindrical was obtained. Through these researches, the distribution trend of equivalent stress provided a reference for the design of the annular sector semicircular cross section vessel.