Advanced Materials Research Vols. 960-961

Abstract: An isothermal flow in a Twin Swirl Combustor (TSC) was simulated with the Renormalized Group (RNG) k-ε turbulence model. The swirling and recirculation intensity was studied under different structures and inlet conditions. The results confirmed that there was a significant negative correlation between the trend lines of the swirl number (S) and reversed flow rate (X_r). The gradient of reversed flow rate was larger in the front and middle parts of the combustor than that of swirl number. The end-surface-inlet structure had a better swirl and recirculation enhancement effect. With the end-surface-inlet structure, the internal swirl and reverse intensity could be flexibly adjusted by switching the swirl intensity of the primary air. Under the structure of staggered-inlet, there was a critical distance between primary and secondary air inlets. When exceeded, it would be more difficult to enhance the swirl and reverse flow effect by increasing the swirl intensity of the secondary air.

Abstract: In order to study the influence of various factors on the heat pipe heat transfer performance, the heat transport limit was taken as test index, nine groups of heat pipe factors matching experiments were carried out based on the orthogonal test method. Four heat pipe internal factors including wick, work media, mass concentration and filling ratio were studied. The results show that the wick has the greatest influence, filling ratio ranks the second, while the work media and mass concentration are not so obviously; the wick and work filling ratio both have significant influences on test index, while work media and mass concentration have little significance.

Abstract: This experiment wastewater treatment plant set up a device of researching different periods of dirt on the different heat exchanger tubes. The moisture test of dirt were derived from tubes of different materials (copper alloy tube, stainless steel pipe, polyethylene-aluminum composite pipe) is between 92.50% and 96.70%, This shows that the quality of per unit area of dry dirt to describe variation is feasible. The induction period of dirt on the copper alloy is between the 0d and 35d, the growth cycle is longer. In the mature period, the quality of per unit area of dry dirt is 2.031 mg/cm². The induction period of dirt on the stainless steel is between the 0d and 20d, the growth cycle is shorter. In the mature period, the quality of per unit area of dry dirt is 2.627 mg / cm²_. The induction period of dirt on the polyethylene-aluminum composite pipe is between the 0d and 35d, the growth cycle is shorter. In the mature period, the quality of per unit area of dry dirt is 2.863 mg/cm².

Abstract: The initial features of large scale oil fires were studied through combustion experiments in oil basins. Four basins were prepared, the diameters of two of them were 2.5m, and another two were 2m. Oil in the basins was ignited simultaneously, and the experiments were conducted twice. The thermal radiation, temperature distribution and components of pollutants were detected and analyzed. Then, some initial features and instructive rules of large scale oil fire disasters were concluded. Known from the experiments, the temperature is high in center areas and low around, in the vertical direction the temperature is high both in upper part and bottom and low in the middle. In addition, the density values of gas pollutants sampled during the experiments can reach to several hundred times of the standard values.

Abstract: The ground coefficient of thermal conductivity is one of the most important parameters of simulating the ground temperature field. The ground coefficient of thermal conductivity of the severe cold region is investigated in this article. Firstly, calculating the ground thermal conductivity with considering the moisture content and porosity; then measuring the thermal conductivity of the 1.5 Meter depth; finally, simulating the unsteady heat transfer model of the shallow buried pipe and the ground with the Matlab software; it founded that the calculation data and the actual data differ only 0.31,but the corresponding ground temperature field vary widely. Thus, it can be concluded that the more precise temperature field of the ground can be simulated with the actual data of ground coefficient of thermal conductivity.

Abstract: The empirical investigation of the dependence of the statistical characteristics of annual run-off of Primorsky region rivers - modulus of flow, variation coefficient, asymmetry ratio, polymodality degree – on the weighted average values of the soil thermal conductivity coefficients within their watershed areas was carried out. The physico-statistical interpretation of the general form of correlation dependences obtained is provided.

Abstract: In order to assess the operational efficiency of cogeneration heating system and measure the systems social, economic, energy-saving and environmental protection benefits in North China, an evaluation index system is built up after analyzing the influence factors which may impact the heating system operation. The association degree function of classical matter element method is improved. And then, an improved matter-element evaluation model is established, which not only can figure out the evaluation grade that heating system belongs to, but also can point out the direction of the further improvement work. Besides, the model has other merits, such as uncomplicated operation, good scalability and so on. Example indicates that this evaluation model has excellent applicability and operability.

Abstract: In high temperature superconducting (HTS) magnet design, it well known that the critical current (I_c) is sensitive to the direction of the local magnetic field. The perpendicular magnetic field component to the face of tape have a larger effect on the I_c of a HTS tape than the parallel component. Thus in HTS magnet design, the magnetic field distribution is the first considering factor. This work presents a HTS magnet design using genetic algorithm to obtain the object. When the length of the tape is certain, the results show that the process gives the optimal number of the double pancake and the inner radius of the magnet.

Abstract: A trend towards increasingly dense and compact architectures has led to unmanageably high heat fluxes in electronic components. A novel heat pipe will be developed. Heat pipe designed is based on the flat plate heat pipe and pulsation heat pipe effective combination. Channel quantity is greatly increased ,as well as compact and homogeneous red copper pulsation plank is severed as the wick，dense and connected channels are served as the passage of the working fluid.

Abstract: A new non-pressure waste heat recycling system was designed and arranged on KHSS0.5-0.7-AⅡ industrial coal-fired boiler to decrease the exhausted gas temperature about 35°C, improve the boiler efficiency about 3.2%. Results showed that this system can avoid low-temperature sulfur corrosion and operate in normal and intermittent water supply condition safely and economically.