Experimental measurements of thermal conductivity of wood were performed using the heat flow meter and transient plane source technique. The specimens were prepared from five species of both softwoods and hardwoods widely available and used in China, with a wide range of density and moisture content. The transverse thermal conductivity of ovendry specimens is presented as a function of density and temperature up to 90°C and is compared with that along the grain direction for two select species. The influence of moisture content up to 23 percent, which is below the typical fiber saturation point of wood, on the transverse thermal conductivity is presented as well. It is shown that the transverse thermal conductivity of wood increases with density, temperature, and moisture content. Linear correlating equations are proposed in terms of these factors.

A numerical study has been carried out for a laminar steady mixed convection flow in a 2D triangular enclosure with an inner rotating coaxial cylinder, with the enclosure filled with ethylene glycol-silicon carbide (SiC-EG). The thermal conductivity and viscosity of the SiC-EG nanofluids were experimentally determined by using a Decagon Devices KD2 Pro thermal property meter and a rotational Brookfield viscometer, respectively. Various pertinent parameters, such as the dimensionless rotation velocity, solid volume fraction, dimensionless radius of the inner cylinder, and Rayleigh numbers, were analyzed to determine their influences on heat transfer and fluid flow. Results clearly show how the direction of rotation of the cylinder affects the thermal performance in a triangular enclosure. It is found that the average Nusselt number increases with rise in the Rayleigh number or as more nanoparticles are added to the base liquid. It was also observed that at constant Rayleigh number, different rotational conditions have remarkable effects on the flow and heat transfer characteristics. 明确在封闭腔内放置旋转柱体时, 柱体尺寸及转速对不同浓度下纳米流体的流动传热的影响。 1. 数值模拟中采用的碳化硅-乙二醇(SiC-EG)纳米流体的重要热物性参数均为实验测量值; 2. 考虑封闭腔内柱体的动态旋转对腔内纳米流体流动传热的影响。 基于对SiC-EG纳米流体导热系数与粘度的实验测量, 采用数值模拟方法探究封闭腔内旋转柱体、 纳米流体浓度以及瑞利数对SiC-EG纳米流体流动传热性能的影响。 1. 在柱体的旋转方向与由自然对流引起的纳米流体流动方向相同的情况下, 置于腔内的旋转柱体可以起到强化传热的效果。 2. 二者旋转方向相反时情况较为复杂, 当柱体尺寸较小且柱体转速较低时削弱传热效果; 当柱体尺寸较大且转速较高而引发的强制对流占主导地位时, 将对腔内传热起到一定的强化效果。

The calorific value of household refuse (HR) is greatly improved after classification, which includes the implementation of sufficient pyrolysis conditions. Therefore, a better pyrolysis effect can be achieved by co-pyrolysis with industrial solid waste (ISW) with high calorific value. In this work, HR and ISW were used as raw materials for co-pyrolysis experiments. The influence on the distribution of three-phase products after co-pyrolysis, the concentration of heavy metals and dioxins in the flue gas, and the distribution of PCDD/Fs isomers were studied. The results showed that, at a temperature of 600 °C and H/C = 1.3, of the formed material, the quantity of pyrolysis gas was approximately 27 wt.%, and the quantity of pyrolysis oil was approximately 40.75 wt.%, which mainly contained alkanes, olefins, and aromatic hydrocarbons. When S/C = 0.008, pyrolysis gas accounted for 25.95 wt.% of the formed material, and pyrolysis oil for 41.95 wt.% of the formed material. The ignition loss rate of pyrolysis coke was approximately 20%, and the maximal calorific value was 14,217 KJ/kg. According to the thermogravimetric experiment, the co-pyrolysis of HR and ISW can promote the positive reaction of pyrolysis, and the weight loss reached 62% at 550 °C. The emission of gaseous heavy metals was relatively stable, and the concentration of heavy metals slightly decreased. The main heavy metals in the ash were Cu, Fe, and Zn. The emission of dioxins could be effectively reduced by the pyrolysis of HR with ISW, and the produced dioxins were mainly synthesized from de novo synthesis. After pyrolysis, the toxic equivalent of dioxins in the flue gas was reduced from 0.69 to 0.29 ng I-TEQ/Nm³, and the distribution of dioxin isomers in the flue gas had little influence. The experimental results provide a theoretical basis for the application of co-pyrolysis technology with HR and ISW.