Advanced Materials Research Vols. 960-961

Abstract: Since the 21^st century, China's power industry has been developing very quickly, and the generated electrical energy has been growing rapidly. Although nuclear power, wind power, solar power generations have been increased, thermal power generation still accounts for more than 80% of the total generating capacity. Thermal power provides an important material basis for the development of the national economy. Therefore, the prediction research on China's thermal power generation trend is becoming a topic of great interest. The fuel of thermal power generation-coal, is an exhaustible resource. Due to the exhaustible constraints the fuel, thermal power generation trend is bound to show a similar trend bell curve as the coal production trend, similar to a bell-shaped curve—a gradual increase to maximum output and then a short peak and a gradual decline. To get more accurate results of future thermal power generation, this paper applies the generalized Weng model to forecast China's thermal power generation peak and trend. The result indicted that the peak of China's thermal power generation appears in 2022 with generating capacity of 51,702 TWh. The generating capacity of thermal power will decrease gradually after 2022. Based on the results, the paper proposes some policy recommendations for the sustainable development of China's electrical energy. China should decrease the percentage of the capacity which comes from thermal generation and reduce the dependence on thermal power generation. Moreover, nuclear, hydraulic, wind and solar power should be developed before the thermal power generation peak.

Abstract: At present, there are many methods of the dredger fill foundation treatment, in which the most widely used application of vacuum preloading method. The dredger fill for test was taken from the Tianjin Binhai new area center fishing port area, separately carried on the self-weight consolidation and vacuum preloading consolidation. Through the indoor test of soil test physical and chemical parameters, comparing the moisture content, soluble salt amount and component, caption exchange capacity, PH value and physical and chemical index. The results show that: the clay content of soil sample in the central fishing port area is higher, degree of aggregation is high, liquid limit is less than 60%, Ip is more than 10, belongs to the low liquid limit clay. Relative self-weight consolidation, soluble salt content of soil samples after vacuum preloading drainage treatment are low, but the particle size composition change less. It is said that parts of salt in the soil samples discharge with water discharge in vacuum preloading process, vacuum preloading effect is better. Introduction All manuscripts must be in English, also the table and figure texts; otherwise we cannot publish your paper.

Abstract: With the numerous applications of high-pressure pipeline, it is very important to simulate the in-service welding of the pipeline.The flow state of the medium in the pipeline can be analyzed, the temperature field and the stress field also can be simulated by applying sysweld software. The medium flow can reduce the welding residual stress and reduce welding stress range during in-service welding. Meanwhile, with the increase of flow rate of the medium, the maximum temperature of inner wall drops and the maximum weld residual stress increases by a slow growth. At the same time, the highest temperature of pipe wall increases rapidly with the increase of heat input, whereas the maximum residual stress of welded joint decreases by a slow trend.

Abstract: In the present paper we investigated the mixing effect of uncompressible jet and cross-flow in Tee pipe based CFD, the model of Realizable was employed as the tool to simulate the flow field, and the model was validated by experimental result of relative research. The mixing effect of jet and cross-flow in various configuration of Tee pipe at different inlet velocity of jet was discussed. The result shows jet and cross-flow mix quickly in near field of injection point, but in the downstream, the mixing effect keeps comparatively steady when z>7d, and there is power relation between the mixing parameter M and r₁×r₂. And r₁ is the ratio of jet pipe diameter to cross-flow pipe diameter, r₂ is the ratio of jet velocity to cross-flow velocity.

Abstract: The objective of this study is to investigate the air entrainment and oxygen transfer characteristics of central-driven ejector with various ejector design parameters. The ejector design parameters are primary nozzle diameter, mixing tube length and diffuser angle. The entrainment ratio decreased with the primary nozzle diameter and diffuser angle, while the ratio increased with the mixing tube length. The trend of dissolved oxygen concentration with the diffuser angle and mixing tube length is equal to the result of entrainment ratio, however, the trend with the primary nozzle diameter is different to the result of entrainment ratio.

Abstract: For a long-distance convey tunnel hydropower station, the changes of its convey tunnel diameter will impact on the pressure at the turbine volute, due to the influence of upper room of surge chamber, surge pressure is difficult to be the controlling value of the pressure at volute, the results also indicate that the influence of pressure pipe diameter on the pressure is more significant than the diversion tunnel diameter. This paper focuses on the pressure pipe diameter by the calculation of a numerical example, the increasing of the pressure at volute caused by the reduction of pressure pipe diameter can be adjusted for security requirements by optimizing the orifice size of surge chamber. Combined with the calculation of the combinational conditions, optimization results are satisfactory. That will reduce the investment of pressure pipe, so it has a certain reference value to the project.

Abstract: The effect of structure size on the flow field in the ejector was investigated by simulating structural parameters of ejector. Simulation results show that the shock occurred in the flow field of the ejector. The entrainment coefficient shows different trends as different structure parameters change. The effects of nozzle position, inlet diameter and nozzle exit ratio were studied respectively. The simulation result revealed that the structural parameters impact the performance of the gas ejector, having certain engineering application value.

Abstract: The use of steam steam ejector is formed in a Laval nozzle entrained flow speed airflow to the power unit of the body, has a simple structure, easy maintenance, stable and reliable, pumping capacity, etc.which is widely used in metallurgy, chemical, pharmaceutical , food and other industries. Based on the comprehensive domestic steam jet pump theory and design based on the results of its variety of design methods reviewed, and in accordance with design features and compare their design processes, raise steam jet pump design trends.

Abstract: In this paper, the computational fluid dynamics (CFD) methodology as well as the shear-stress transport (SST) k-omega turbulence model was adopted to model the air pressure reducer (APR). Changing the gas needle’s displacement of APR continuously, the writer obtains the displacement-pressure characteristics of APR. In order to demonstrate the validity of these characteristics, a physical experiment was conducted, which generates another displacement-pressure characteristic. Comparing the two characteristics with a good agreement, it is indicated that the CFD methodology is suitable to study the displacement-pressure characteristics of APR.

Abstract: In this paper, Couette flow is mainly discussed by studying the general flow behaviour mechanism and importing the velocity slip and temperature jump boundary condition. By analyzing velocity, temperature and pressure profiles at different Knudsen numbers, we concluded that Couette flow is driven by shear stress. The shear stress lies in stream direction. Viscous heat causes the increasing of the fluid’s temperature. With the increasing of Knudsen numbers, the increasing speed increases. It’s in the beginning of transition region that the heat flux has the maximum.