Shijun You

The Carbonization Characteristics Studies of Corn Stalk in a Fixed Bed Reactor

Biomass energy is an important resource in resolving the energy crisis and pyrolysis is the most important method in making use of it. Pyrolysis in the absence of oxygen is called as carbonization. Biomass could be converted to charcoal, liquid and gas products using the carbonization process at different temperatures. The chemical composition and yields of charcoal, liquid and gas are determined as a function of the carbonization temperature. Corn stalk is one of the most important biomass materials in northern China. This paper studied the effect of temperature on the carbonization characteristics of corn stalk in a fixed-bed reactor. The results may provide reference in utilizing of biomass.

CFD-Based Prediction on Thermal Pollution

This paper describes the work conducted to establish a thermal discharge model, by using the commercial computational fluid dynamics code FLUENT, in order to predict temperature distribution resulting from the thermal discharge into a lake. The results show that the thermal influence area is limited, although this thermal discharge system can pollute the water environment. After this thermal discharge is finished, the water temperature can recover in one hour. Keywords-Environmental protection; water pollution control; thermal pollution; FLUENT

Effect of Window Characteristics on Indoor Air Quality in Residential Housing

With serious energy crisis and high demand for Indoor Air Quality (IAQ), natural ventilation has taken more and more attention, which is recognized to be an effective and economic method to decrease the risk of Sick Building Syndrome (SBS), as well as reducing air-conditioning opening time, and thus saving energy. In view of windows characteristics having a great effect on ventilation, the paper discussed the influence of air inlet window type and area ratio of open window to floor on indoor steady-state contamination of CO 2 and steady-state time. In addition, for tilt, hopper or grille window, the larger opening angle, the better ventilation performance, yet once over 30deg, its influence on steady-state contamination became unobvious, so, the paper only discussed the situation with opening angle 30deg, inside. And to calculate more accurately and quickly, as well as conveniently and cost effectively, CFD model was used, which was firstly validated by experiment, good agreement in between, with absolute error in simulation 9.2%. Then, combined with the measured outdoor weather data in Tianjin, the results were obtained, push-pull window was the preferred window type, lower indoor average steady-state contamination of CO 2 and shorter steady-state time, 550 ppm and 6.5 min, with area ratio of open window to floor beta 5%. Moreover, on this basis, the optimal area ratio of open window to floor beta for push-pull window was studied, which was proposed to be or larger than 10%.

Experimental Study on Sterilization Performance of Compound Air Cleaner

The split type air conditioner has less control of indoor biological particles, volatile organic compounds and other pollutants. A compound air cleaner representing and photo catalytic purifying effect is equipped to the residential conditioner. The sterilization performance of the air cleaning conditioner is tested in an office room using airborne microbe Colony Forming Unit (CFU) index. It is observed that this type of air cleaning conditioner could reduce the microbe count in the air rapidly to provide healthy indoor environment. More investigation is needed to study the sterilization performance contributed by electrostatic filter and photo catalyst respectively.

The Pollution Characteristics Analysis of Benzene Series in a Newly Decorated Office Building

In order to study the pollution characteristics of benzene series in a newly decorated office building, the method of active carbon absorption sampling combined with gas chromatographic analysis was used in monitoring the concentrations changes of benzene series in four typical zones in a newly decorated office building in Tianjin. The laws of benzene series concentrations changes and impacted factors were summarized, that is, the concentrations of three main kinds of benzene series in the decorated office building were higher than the allowed values of national standard just after decoration and then began to reduce with time. Through studies, we found that toluene could cause more serious pollution among benzene series on indoor air and natural ventilation was the most effective and economical method in reducing the benzene series concentrations in buildings.