Advanced Materials Research Vols. 516-517

Abstract: This paper experimentally study on CH₄ / air co-flow diffusion combustion on the upper surface of porous media packed beds. The flame height and flame shape were reconstructed from the upper and the side of the combustor. The influence of the height of the packed bed on the flame height and flame shape is reported. It is shown that the flame height decreases rapidly and the circular diameter increases rapidly with increase the height of the packed beds.

Abstract: This article discussed the temperature field and heat transfer inside catalytic combustion furnace with Pd-based honeycomb monoliths of lean natural gas-air mixtures. The monoliths need to be ignited by gas phase combustion with the excessive air coefficient at 1.63 during the period of start-up process. After local catalytic ignition, a steady state has reached. The temperature field was measured by thermocouple K of diameter 1.0. It was shown that the temperature gradient changed according to the different position inside catalytic combustion furnace. When the furnace was used for heating equipment, heat transfer included mainly heat radiation and convection. For high radiation heat, local surface temperature of monoliths plays a decisive role.

Abstract: The simulation results shows that pilot injection, intake preheating, main injection advance angle have a big impact on ignition performance of diesel engine. After using pilot injection, the average cylinder pressure and temperature, and the accumulated heat release increased, ultimately the fuel efficiency had been improved. By using the intake preheating, combustion efficiency had been improved for combustible mixture gas formed easily and combustion conditions significantly improved in cylinder. Besides, an appropriate main injection advance angle could improve the combustion of ignition delay period and increased the engine power and fuel efficiency.

Abstract: This paper develops a thermodynamic input-output analysis of industrial economy for Hubei Province, which accounts for the flow of cumulative exergy consumption of primary energy. Firstly, the basic situation of energy utilization in 2007 Hubei Province is analyzed. Then two different methods are adopted for thermodynamic input-output analysis in this paper, which are named as industrial cumulative exergy consumption and ecological cumulative exergy consumption. Results show that primary energy extraction sectors and raw material processing sectors have prominent peaks on both industrial cumulative exergy consumption and ecological cumulative exergy consumption for the case of Hubei Province. In terms of primary energy extraction sectors, traditional energy which has high exergy content should be substituted for new energy which has low exergy content. In terms of raw material processing sectors, high energy efficient and clean energy utilization technology should be promoted.

Abstract: Abstract. temperature and species distributions of an atmosphere coflow laminar CH₄/air diffusion flame was studied by numerical simulation. We solve the steady equations for the species mass fraction, energy, momentum with detailed gas-phase reaction mechanism and complex thermal and transport properties to predict the velocity, temperature, species distributions for different dilute level. Results indicated that the predicted temperature and species are in excellent with available experiment date at different dilute level. In addition, it is indicated that adding N₂ in the fuel has a significant influence on the flame temperature and species distribution.

Abstract: This paper has built a mathematical model for the evaporating characteristics of the grooved micro heat pipe’s thin film region and computed them in a specific working condition. The evaporating model of Wayner was employed in this mathematical model. The results from computation showed, for the H2O and NH3 as working fluid, at the beginning of the thin film region, the heat flux raised rapidly to a peak value and then declined to almost 0 also rapidly in a very short distance. Differently, for the Na and K as working fluid, the heat flux raised quickly but declined slower. Therefore, the alkali metals working fluids had larger area of high heat flux covered. The results indicated that the alkali metals working fluid has better evaporating characteristics for the high-temperature heat pipe than normal working fluids.

Abstract: Ozone combustion-supporting is an effective means of internal combustion engine energy-saving. The theory of plasma method to produce ozone is mature, and how to improve the efficiency of ozone reaction becomes the key point. The chemical reaction process under the conditions of plasma involves the physical parameters and problems of gas discharge. Withal, research on the DBD (dielectric barrier discharge) experiments is carried on. And the key factors of improving the efficiency of the reaction, such as the physical parameters of discharge uniformity and the discharge power, are examined.

Abstract: A numerical simulation study on the horizontal thick and thin firing burner with distorted clapboards was conducted based on the realizable k–ε turbulence and Lagrange random particle orbital models. The flow field and pulverized coal concentration distribution were also determined. Moreover, this study achieved the following results. The velocity distributions in the burners with clapboards at 40°, 90°, and 140° distortion angles were close to the experimental values. The separation degree of pulverized coal concentrations in this kind of burner was higher, and the airflow rotated forward in a clockwise direction. Lastly, the thick and thin side air distributions were right- and left-skewed at the exit, respectively.

Abstract: Abstract. Aiming at analyzing boiling mechanism and confirming rapid phase Abstract. Aiming at analyzing boiling mechanism and confirming rapid phase transfer (RPT) taking place conditions of LNG discharging on water. The models of pool spreading, heat and mass transfer rate and LNG’s property are coupled in this paper. The conditions of RPT has been confirmed, which included LNG directly contacting with water and the water temperature should higher than LNG’s superheat limit temperature, but the RPT would not take place if the LNG boils on ice. The model of LNG discharging on water has been established in this paper, which is used to simulate Boe and Burro-9 experiments. The results showed that the models can simulate evaporation and boiling rate well, and can be used in predicting the initial time of RPT happening when the discharging process is calm and the location of discharging is near the water surface.

Abstract: By the use of the map of the thermal resistance among volume cells, we establish a coupled heat transfer model of the hot gas, chamber wall and coolant. A reduced one-dimensional model was employed for the coolant flow and heat transfer, and three dimensional heat transfer model was used to calculate the coupling heat transfer through the wall, considering heat transfer at circumferential direction, axial direction and radial direction. Based on the study the mechanism of the cooling structure heat transfer, the computing model was employed and achieved the rule of heat flux and temperature of gas wall. Simultaneously, influence of different cooling structure was performed. The results indicated that the cooling structure with raised structure could better reduce the temperature of the chamber wall.