Wei Xinli

Performance Enhancement of a PCM Cold Storage under Condition of Heat Flux

The objective of this work presents the numerical investigations of the enhancement performance of an phase change cold storage unit which is used for an air conditioning system during the solidification (discharge) process under the boundary condition of heat flux. The shell-and-tube cold storage unit is a typical tube-foil arrangement composed of an energy storage. The aluminum foils are arranged orthogonal to the axis of the tubes, and phase change material (PCM) fills the space between foils and tubes while the heat transfer fluid flows inside the tubes. The buildings use nighttime cold accumulation in PCM and cool hot air during the daytime in summer. When the cooling load is lower than the nominal cooling capacity of the system, the cold storage unit can store extra cold energy of the system to cool the interior of the building. The development of the model for the cold storage enables a detailed analysis of heat transfer process. The effects of foils and parameters on the behaviour of the performance are examined. Results show that by reducing the foil pitch or increasing heat flux has a significant enhancement effect on the heat transfer process.

Energy Optimization of Biomass Pyrolysis and Liquefaction System in CFB

Biomass pyrolysis and liquefaction technology needs inert carrier gas and high energy consumption. On the basis of analyzing its energy consumption and the using way of char and off-gas, energy in the pyrolysis and liquefaction system in CFB is optimized by using a part of pyrolysis gas for carrier gas and off-gas to burn to heat biomass raw material. Inert carrier gas and its heating and cooling energy consumption are saved and off-gas is used to heat biomass instead of to exhaust to air after this optimization.

Numerical study of light reflection absorption affected by sinusoidal-corrugated solar air collector

The influences on the absorption rate with different slope of incident light and aspect ratio are presented. The results show that the effect of aspect ratio on the absorption rate is larger, while the slope of incident light is relatively smaller. The results of the present work imply that the rational aspect ratio is 1. According to this conclusion, the optical path of sinusoidal-corrugated solar air collector with aspect ratio 0.5, 1 and 1.5 is simulated respectively by TRACEPRO software using. The conclusion is also verified by the simulations.