沥青混合料拌和楼生产质量控制的研究

从沥青拌和楼的冷料控制、热料控制、搅拌控制等角度论述了不同型号沥青拌和楼生产混合料时在质量控制过程中的经验，可为同行提供参考。

Structural design and experimental research of microwave radiation heater for asphalt pavements

In order to improve the efficiency of heating and the uniformity of temperature distribution in recycling asphalt mixtures, a pyramidal radiation heater is designed. The principles of designing horn surface size and antenna length are established according to the law of energy conservation and microwave antenna radiation theory. Modeling and simulation are carried out using IE3D software. The simulation results demonstrate that, with a fixed horn surface size, the shortened electric antenna length is the main factor leading to the improved heating uniformity. On the other hand, with a fixed antenna length and diminished surface size, the standing wave ratio decreases with the improved radiation efficiency. Furthermore, the efficiency of radiation drops with increased distance between the horn surface and the asphalt pavement. Microwave heating experiments are carried out using this type of heater. The temperature distribution of asphalt samples is obtained by the grid temperature measurement method, and Matlab simulation is performed. The experimental results are in good agreement with the simulation.

Forming regularity and relation between composition and property of B_2O_3-BaO-ZnO glass

B2O3-BaO-ZnO glass was prepared by using conventional melt quenching technology. The forming regularity and the relationship between the composition and the property of B2O3BaOZnO glass were investigated. The results show that the composition range for forming B2O3BaOZnO glass is very wide, but the content of B2O3 has a limit within mole fraction of 25%75%. When the content of B2O3 is over the limit, the melt will be divided into two phases with different compositions and structures, whereas too low content of B2O3 will result in the crystallization of the melt during the cooling process. The thermal expansion coefficient, the transition temperature and the resistivity of the glass at room temperature are （510）×10 -6℃ -1, 480620℃ and （1.53.0）×10 10Ω·m, respectively.

Hydrogenation reaction characteristics and properties of its hydrides for magnetic regenerative material HoCu_2

The hydrogenation reaction characteristics and the properties of its hydrides for the magnetic regenerative material HoCu_2(CeCu_2-type) of a cryocooler were investigated. The XRD testing reveals that the hydrides of HoCu_2 were a mixture of Cu, unknown hydride Ⅰ, and unknown hydride Ⅱ. Based on the PCT(pressure-concentration-temperature) curves under different reaction temperatures, the relationships among reaction temperature, equilibrium pressure, and maximum hydrogen absorption capacity were analyzed and discussed. The enthalpy change ΔH and entropy change ΔS as a result of the whole hydrogenation process were also calculated from the PCT curves. The magnetization and volumetric specific heat capacity of the hydride were also measured by SQUID magnetometer and PPMS, respectively.

Effect of temperature on formability of glass mat reinforced thermoplastic sheets with ductile dummy sheets

Given the increasing use of glass mat-reinforced thermoplastic(GMT)composites,the formability of GMT sheets is currently a topic of research.A new sheet forming process for solidified GMT was developed.In this process,a GMT sheet was sandwiched by dummy metallic sheets during deep drawing.The dummy metallic sheets acted as protective materials and media for heating the GMT sheet.In this study,tensile tests of GMT specimens were carried out under different temperature conditions.The effect of temperature on the tensile deformation was analyzed.The effect of temperature on the deep drawing process of GMT sheets with dummy sheets was further investigated.Finite element method(FEM)was conducted to simulate the deep drawing process.In the drawing force rising stage,the law of drawing force with the depth of the drawing was analyzed using FEM and experiments.

Effects of process parameters on warpage of rapid heat cycle moulding plastic part

The effects of process parameters in rapid heat cycle moulding （RHCM） on parts warpage were investigated. A vehicle-used blue-tooth front shell （consisting of ABS material） was considered as a part example manufactured by RHCM method. The corresponding rapid heat response mould with an innovational conformal heating/cooling channel system and a dynamic mould temperature control system based on the Jll-W-160 type precise temperature controller was proposed. During heating/cooling process, the mould was able to be heated from room temperature to 160 ~C in 6 s and then cooled to 80 ~C in 22 s. The effects of processing conditions in RHCM on part warpage were investigated based on the single factor experimental method and Taguchi theory. Results reveal that the elevated mould temperature reduces unwanted freezing during the injection stage, thus improving mouldability and enhancing part quality, whereas the overheated of mould temperature will lead to defective product. The feasible mould temperature scope in RHCM should be no higher than 140 ~C, and the efficient mould temperature scope should be around the polymer heat distortion temperature. Melt temperature as well as injection pressure effects on warpage can be divided into two stages The lower stage gives a no explicit effect on warpage whereas the higher stage leads to a quasi-linear downtrend. But others affect the warpage as a V-type fluctuation, reaching to the minimum around the heat distortion temperature. Under the same mould temperature condition, the effects of process parameters on warpage decrease according to the following order, packing time, packing pressure, melt temperature, injection pressure and cooling time, respectively.

Utilization Starch of Avocado Seed （Persea Americana Mill.） as a Raw Material for Dextrin

Starch ofavocado seeds can be used as an alternative source of starch because it contains 80.1% starch. Natural starch can be made into a modified starch, for example dextrin. Dextrin can be made by using acid or enzyme hydrolysis. The purposes of this research were determine the concentration of hydrochloric acid （HCl）, the temperature and heating timein the optimum process of hydrolysis of starch into dextrin and to determine the quality of the resulting product dextrin terms of Indonesian National Standard 01-2593-1992. The methode was used in this research is hydrolisis with hydrochloric acid （HCl）. The results processing into starch avocado seed yield is 23.15%. HCl concentration, temperature and heating time significantly affect the value of dextrose equivalent （DE）, viscosity and part soluble in cold water. There is interaction between HCl concentration, temperature and heating time on the value of DE, viscosity and part soluble in cold water. Optimum conditions of process was obtained at a concentration of 0.15 N HCl, 30 minutes heating time and heating temperature of 90 ℃. Dextrose equivalent （DE） value is 19.61%. The value of solubility in cold water is 90.19%. Viscosity value is 1.61 ° E. Dextrin is not accordance with the standards of quality parameters Indonesian National Standard 01-2593-1992. Dextrin produced should be applied to non-food industry.

Research on application of different particle sizes of cordierite on castable refractory

Effect of different particle sizes of cordierite on properties of castable refractory by different heat treatment temperatures were investigated respectively with mullite and bauxite as raw materials, calcium aluminate cement as binders. After 24 h curing in mould and another 24 h curing at 110 ℃ after demoulding, the specimens were heat treated at 1 000 ℃, 1 300℃ and 1 500℃ for 3 h, respectively. The bulk density （ BD）, permanent linear change （ PLC）, modulus of rupture（MOR） and clod crushing strength（CCS）, thermal expansion coefficient and thermal shock resistance were examined. The results show that there is no obvious effect on adjusting permanent linear change and bulk density of castables by adding different particle sizes of cordierite at low temperature and intermediate temperature. Modulus of rupture of castable increase with the decreasing of the particle sizes of cordierite after heat treated by 1 000 ℃ and 1 300℃. In this experiment, thermal shock resistance of the castable with cordierite whose particle size is 0 - 1 mm is the best.

Characterization and Modification of Indonesian Natural Zeolite for Hydrocracking of Waste Lubricant Oil into Liquid Fuel Fraction

Modification and characterization of natural zeolite under some various methods for hydrocracking catalyst of waste lubricant to gasoline and diesel fractions have been conducted. Natural zeolite from Klaten was activated using hydrothermal treatment at temperature 500 ℃ for 6 h （produced ZAAHd）, the ZA sample was treated with hydrothermal followed by Microwave （produced ZAAHdM）, the ZA sample was treated with HCI 3 N at temperature of 90 ℃ for 30 min （produced ZAAH）, the ZAAH sample was heated in to microwave （produced ZAAHM）, the ZAAHM was treated hydrothermal （produced ZAAHMHd）, the ZAAHMHd sample was heated in to microwave （produced ZAAHMHdM）, soaking of natural zeolit activated by HCl-microwave-hydrothermal-microwave in NH4NO3 1 N which was stirred using stirer at room temperature for 24 h （produced ZAAHMHdMN） and the ZAAHMHdMN sample was heated into microwave （ZAAHMHdMNM）. The heating process by microwave was conducted at 550 watt for 15 rain. Catalyst characterization involved determination of the number of total acid sites using gravimetric method with vapour adsorption of NH3 and pyridine, catalyst crystallinity by XRD （X-ray diffraction） and TO4 （T= Si and AI） site by infra red spectrophotometer （IR）. Hydrocracking of waste lubricants oil was performed in a fixed bed reactor of stainless steel at temperature of 450 ℃, H2 flow rate of 15 mL/min., feed/catalyst ratio of 5. Liquid products of the hydrocracking were analyzed using GC （gas chromatography）. The characterization results showed that various modification of natural zeolite increased acidity and dealumination degree of the catalysts. Products of the hydrocracking were liquid, coke, and gas fractions. Liquid products consisted of gasoline fraction （C5-C12）, diesel fraction （C12-C20）, and heavy oil fraction （〉 C20）.Thc conversion of liquid products was increased with the increase of catalyst acidity. The greatest liquid product conversion was produced by the ZAAHMHdMNM catalyst, i.e., 56.80%, with selectivity towards gasoline, diesel, and heavy oil fractions was 88.37%, 8.61% and 3.02%, respectively. The increase of catalyst acidity increased the selectivity of gasoline fraction.

Bifunctional 3D n-doped porous carbon materials derived from paper towel for oxygen reduction reaction and supercapacitor

Designing and fabricating cheap and active bifunctional materials is crucial for the development of renewable energy technologies.In this article,three-dimensional nitrogen-doped porous carbon materials(NDPC-X,in which X represents the pyrolysis temperature) were fabricated by simultaneous carbonization and activation of polypyrrole-coated paper towel protected by a silica layer followed by acid etching.The material had a high specific surface area(1,123.40 m^2/g).The as-obtained NDPC-900 displayed outstanding activity as a catalyst for the oxygen reduction reaction(ORR) as well as an electrode with a high specific capacitance in a supercapacitor in an alkaline medium.The NDPC-900 catalyst for the ORR exhibited a more positive reduction peak potential of à0.068 V(vs.Hg|HgCl^2) than that of Pt/C(-0.121 V),as well as better cycling stability and stronger methanol tolerance.Moreover,the NDPC-900 had a high specific capacitance of 379.50 F/g at a current density of 1 A/g,with a retention rate of 94.5% after 10,000 cycles in 6 mol/L KOH electrolyte when used as an electrode in a supercapacitor.All these results were attributed to the effect of a large surface area,which provided electrochemically active sites.This work introduces an effective way to use biomass-derived materials for the synthesis of promising bifunctional carbon material for electrochemical energy conversion and storage devices.

Thermal Analysis of Metal Foam Matrix Composite Phase Change Material

In this paper,CPCM(Composite Phase Change Material)was manufactured with metal foam matrix used as filling material.The temperature curves were obtained by experiment.The performance of heat transfer was analyzed.The experimental results show that metal foam matrix can improve temperature uniformity in phase change thermal storage material and enhance heat conduction ability.The thermal performance of CPCM is significantly improved.The efficiency of temperature control can be obviously improved by adding metal foam in phase change material.CPCM is in solid-liquid two-phase region when temperature is close to phase change point of paraffin.An approximate plateau appears.The plateau can be considered as the temperature control zone of CPCM.Heat can be transferred fiom hot source and be uniformly spread in thermal storage material by using metal foam matrix since thermal storage material has the advantage of strong heat storage capacity and disadvantage of poor heat conduction ability.Natural convection promotes the melting of solid-liquid phase change material.Good thermal conductivity of foam metal accelerates heat conduction of solid-liquid phase change material.The interior temperature difference decreases and the whole temperature becomes more uniform.For the same porosity with a metal foam,melting time of solid-liquid phase change material decreases.Heat conduction is enhanced and natural convection is suppressed when pore size of metal foam is smaller.The thermal storage time decreases and heat absorption rate increases when the pore size of metal foam reduces.The research results can be used to guide fabricating the CPCM.

Thermal Analysis of a Phase Change Material Based Heat Sink for Cooling Protruding Electronic Chips

This work aims to numerically study the melting natural convection in a rectangular enclosure heated by three discreet protruding electronic chips. The beat sources generate heat at a constant and uniform volumetric rate. A part of the power generated in the heat sources is dissipated to a phase change material （PCM, n-eicosane with melting temperature, Tm = 36℃）. Numerical investigations were carded out in order to examine the effects of the plate thickness on the maximum temperature of electronic components, the percentage contribution of plate heat conduction on the total removed heat and temperature profiles in the plate. Con＇elations for the dimensionless secured working time （time to reach the threshold temperature, Tcr = 75℃） and the corresponding liquid fraction were derived.

Study of Cycle Output Improvement by Work-Fluid Including Phase Change Material

This paper deals with the output improvement of heating and cooling cycle by using the work-fluid including phase change material.The experimental study is carried out by heat exchange between work-fluid and heat transfer surface.The work-fluid is flown to a high temperature or a low temperature heat transfer surface from the narrow path.In order to increase the amount of the heat transmission,a trace of Diethylether(boiling point 34.8 ℃),as a phase change material(PCM),is added to the work-fluid.The parameters of the experiment are additive amount of PCM,the rotational speed of the displacer piston and the temperature of heat transfer surface.It is clarified that the increasing of engine cycle output is brought by the PCM addition.The effect of PCM addition is evaluated by output ratio which is defined from the experimental cycle output data.The requirements for acquiring the increasing effect of output by adding PCM are clarified.

Deterioration in Heat Transfer of Endothermal Hydrocarbon Fuel

Numerical studies under supercritical pressure are carried out to study the heat transfer characteristics in a single-root coolant channel of the active regenerative cooling system of the scramjet engine, using actual physical properties of pentane. The relationships between wall temperature and inlet temperature, mass flow rate, wall heat flux, inlet pressure, as well as center stream temperature are obtained. The results suggest that the heat transfer deterioration occurs when the fuel temperature approaches the pseudo-critical temperature, and the wall temperature increases rapidly and heat transfer coefficient decreases sharply. The decrease of wall heat flux, as well as the increase of mass flow rate and inlet pressure makes the starting point of the heat transfer deterioration and the peak point of the wall temperature move backward. The wall temperature increment induced by heat transfer deterioration decreases, which could reduce the severity of the heat transfer deterioration. The relational expression of the heat transfer deterioration critical heat flux derives from the relationship of the mass flow rate and the inlet pressure.

The Study on the Heat Transfer Characteristics of Oxygen Fuel Combustion Boiler

According to 350 MW and 600 MW boilers,under oxygen fuel condition,through the reasonable control of the primary and secondary flow and the correct option and revision of mathematical model,the temperature distribution,heat flux distribution and absorption heat distribution,etc.was obtained which compared with those under air condition.Through calculation,it is obtained that the primary and secondary flow mixed well,good tangentially fired combustion in furnace was formed,the temperature under air condition obviously higher than the temperature under O26 condition.The adiabatic flame temperature of wet cycle was slightly higher than that of dry cycle.The maximum heat load appeared on the waterwall around the burner area.The heat load gradually decreased along the furnace height up and down in burner area.The heat absorption capacity of the furnace under O26 was lower than that under the air condition.The heat absorption capacity of the platen heating surface under 026 was equal to that under air condition.And the heat absorbing capacity of waterwall under O26 was about 7%~12% less than that under air condition.

One-Dimensional Analysis of Supersonic Two-Stage HVOF Process

The one-dimensional calculation of the gas/particle flows of a supersonic two-stage high-velocity oxy-fuel(HVOF) thermal spray process was performed. The internal gas flow was solved by numerically integrating theequations of the quasi-one-dimensional flow including the effects of pipe friction and heat transfer. As for the supersonicjet flow, semi-empirical equations were used to obtain the gas velocity and temperature along the centerline. The velocity and temperature of the particle were obtained by an one-way coupling method. The material ofthe spray particle selected in this study is ultra high molecular weight polyethylene (UHMWPE). The temperaturedistributions in the spherical UHMWPE particles of 50 and 150 m accelerated and heated by the supersonic gasflow was clarified.