Optimization on temperature efficiency and switch time of thin-walled regenerator with perturbation analysis

The heat transfer characteristic of honeycomb ceramic regenerator was optimized by the perturbation analytical-numerical method. The results show that there is a temperature efficiency peak and the corresponding optimal switch time. The decrease of air oxygen concentration leads to the decrease of maximum temperature efficiency. Optimal switch time is directly proportional to the matrix thickness. The solid heat conduction along the flow direction and the regenerator heat storage capacity of the unit volume have no impact on maximum temperature efficiency and optimal switch time. The temperature efficiency tendency based on the semi-analysis is the same as dispersion combustion tests with low oxygen concentration, and optimal switch time of 2-4 s agrees well with that of 4 s in high-temperature gasification tests. The possibility of design, operate and control a thin-walled regenerator with high efficiency by means of the perturbation method is proved.

Temperature Effects on Information Capacity and Energy Efficiency of Hodgkin-Huxley Neuron

Recent experimental and theoretical studies show that energy efficiency, which measures the amount of infor- mation processed by a neuron with per unit of energy consumption, plays an important role in the evolution of neural systems. Here we calculate the information rates and energy efficieneies of the Hodgkin-Huxley （HH） neuron model at different temperatures in a noisy environment. It is found that both the information rate and energy efficiency are maximized by certain temperatures. Though the information rate and energy efficiency cannot be maximized simultaneously, the neuron holds a high information processing capacity at the tempera- ture corresponding to the maximal energy efficiency. Our results support the idea that the energy efficiency is a selective pressure that influences the evolution of nervous systems.

Calculation of the Efficiency of Regenerative Air Heat Exchanger with Intermediate Heat Carrier

The study deals with a new regenerative air heat exchanger with an inter­mediate heat carrier used in the systems of room ventilation.A physical and mathematical model of the heat transfer process is proposed.The in­fluence of design and operating parameters on the temperature efficiency of the heat exchanger is analyzed.The possibility of a significant increase in its efficiency with a decrease in the packing diameter is shown.As a re­sult of calculations,it was found that with a decrease in the filling height,the maximum temperature efficiency shifted towards a decrease in the air flow rate from its value determined from the equality of water equivalents of liquid and air.

Effect of six kinds of scale inhibitors on calcium carbonate precipitation in high salinity wastewater at high temperatures

Precipitation of calcium carbonate （CaCOs） scale on heat transfer surfaces is a serious and expensive problem widely occurring in numerous industrial processes. In this study, we compared the scale inhibition effect of six kinds of commercial scale inhibitors and screened out the best one （scale inhibitor SQ-1211） to investigate its scale inhibition performance in highly saline conditions at high temperature through static scale inhibition tests. The influences of scale inhibitor dosage, temperature, heating time and pH on the inhibition efficiency of the optimal scale inhibitor were investigated. The morphologies and crystal structures of the precipitates were characterized by Scanning Electron Microscopy and X-ray Diffraction analysis. Results showed that the scale inhibition efficiency of the optimal scale inhibitor decreased with the increase of the reaction temperature. When the concentration of Ca^2＋ was 1600 mg/L, the scale inhibition rate could reach 90.7% at 80℃ at pH 8. The optimal scale inhibitor could effectively retard scaling at high temperature. In the presence of the optimal scale inhibitor, the main crystal structure of CaCOs changed from calcite to aragonite.