Rapid Heating System Research Articles

Porosity evolution of Minhe oil shale under an open rapid heating system and the carbon storage potentials

The ideal non-collapse heated oil shale reservoir may lead to the maximum preservation of pores and fractures. However, the previous research on the pore evolution during heating in oil shale reservoirs has focused only on the analysis of capillary pores, ignoring the supercapillary pores (including fractures) that can provide the free flow of fluid. Through open thermal system experiments, combined with multi-scale visual statistics and quantitative testing, this paper reveals that the surface porosity of supercapillary pores increased from 0.27% to 15.95% and the porosity of capillary pores and microcapillary pores increased from 0% to 39.55%, in which the contribution rate of organic matter pores increased from 2.36% to 87.46%. From the perspective of the trap, we propose that the displacement pressure, breakdown pressure and overburden pressure of surrounding rock determine the pressure of injected CO2. Regarding the adsorption and free state, through an improved formula for carbon storage potentials, the maximum theoretical CO2 storage per unit volume for the Minhe depleted oil shale reservoir was estimated to be approximately 0.261 × 109 t/km3. Thus, a depleted oil shale reservoir is a suitable place for CO2 storage owing to the large storage potential.

Experimental and computational analysis of microbial inactivation in a solid by ohmic heating using pulsed electric fields

Pulsed electric field technology (PEF) has traditionally been used as a technique to inactivate microorganisms in liquid foods at temperatures below those used in heat treatments; however, application of high-intensity PEF (E>1 kV/cm) at high frequencies (>10 Hz) can allow rapid and volumetric solid food electrical heating in order to replace traditional convection/conduction heating that progresses from the heating medium to the inside of the product. This investigation is the first one to evaluate the inactivation of Salmonella Typhimurium 878 in a solid product (cylinder of technical agar used as reference solid) by applying PEF treatments (2.5 and 3.75 kV/cm, and up to 9000 microseconds) at 50 Hz. The evolution of temperature in different locations of the agar cylinder was measured by observing the variability of heating rates depending on location and PEF intensity. Microbial inactivation was determined and compared with isothermal heat treatments that predicted similar inactivation values, but did not detect additional inactivation. Computational analysis enabled us to predict temperature and microbial inactivation for any spatial and temporal distribution of the cylinder agar by detecting the coldest point in the transition zone between the high-voltage electrode, the agar, and the plastic container of the treatment chamber. In order to evaluate the variability of the temperature, computational predictions were done each 0.5-mm. The difference between the coldest and the hottest point (e.g. at the center of the cylinder) resulted in around 10 ∘C and 10 second variation in temperature and processing time, respectively. In any case, it was possible to obtain 5-log10-reductions after 60 s of PEF treatments when using 2.5 kV/cm and 50% reduction for 3.75 kV/cm. These results suggested the potential of PEF technology as a rapid heating system based on ohmic heating for microbial inactivation in solid food products.

超臨界水熱合成法によるSrフェライト粒子の合成

Sr ferrite nanoparticles were synthesized by supercritical hydrothermal synthesis. The precursor as a raw material was prepared by neutralizing a solution of iron nitrate (III) and strontium nitrate with KOH. First, a batch type reactor was used to explore the condition (temperature and reaction time) to synthesize Sr ferrite. As a result, formation of Sr ferrite was observed under supercritical water condition, 653 K and 10 min even though hematite was included in the product as impurities. However, all the hematite was changed to Sr ferrite when the reaction time was enlongated to 60 min. Particle size was around 1 μm. In the case of a flow system that can achieve rapid heating by mixing precursor with high temperature water, even at very shot reaction time Sr ferrite was synthesized in a single phase without any inpurity. It is because of the rapid heating system that could suppress the formation process of hematite at a lower temperature range. The particle size was as small as 200 nm, which is probably because of the extremely high supersaturation in supercritical state just after the rapid heating. Effect of synthetic parameters on microstructure for obtained Sr ferrite nano-materials was investigated. Magnetization characteristic of Sr ferrite nanoparticle synthesized by the flow-through supercritical water synthesizer was also evaluated.

Carbon Heating Tube Used for Rapid Heating System

We report a microwave heating system with a carbon heating tube (CHT) which was made by a 4-mm diameter quartz tube filled with carbon particles and Ar gas at 1400 Pa. A 60-mm-long CHT was set in a cavity in which 2.45-GHz microwave was introduced. Via nearly complete absorption of a microwave power of 200 W by carbon in the CHT during multi-reflection of the microwave in the cavity, the CHT was effectively heated to 1279 °C at 33 s after the microwave initiation, which was observed by the radiation-type thermometer. Moreover, the control of the CHT temperature was demonstrated with a home-made proportional–integral–differential feedback circuit which regulated the magnetron power source using a signal of the thermometer. The control of temperature at 1100 °C was successfully realized. Crystallization of a 58-nm-thick amorphous silicon thin film formed on the glass substrate was demonstrated by mechanically moving the silicon sample just below the heated CHT. A high crystalline volume ratio of 0.92 was achieved. Furthermore, heating of 500- $\mu \text{m}$ -thick-n-type silicon substrate implanted with $1.0\times 10^{15}$ cm−2 phosphorus and boron atoms with the CHT resulted in activation of the doped regions. Rectified diode characteristics were achieved.

1P2-N03 環境温度駆動型の座屈アクチュエータによる微小重力落下試験用ローバーの跳躍特性評価(宇宙ロボット)

Asteroid probe Hayabusa 2 is developed by JAXA. Asteroid exploration rovers will be carried by Hayabusa 2. In our research project, we have developed an environmental-temperature-driven buckling actuator with a bimetal thin plate for a hopping mechanism of the rover. In this study, to characterize the hopping capability of the actuator, we conducted microgravity examination in ZARM drop tower. We fabricate a test rover for the microgravity examination with a rapid heating system for actuation in short free-fall time. Although reaction force from baseplate was incomplete in take-off, the rover hopped with a vertical velocity of 3.12 mm/s with 0.035 rad/s rotating rate.

Single Neuron PID Control of Aircraft Deicing Fluids Rapid Heating System

Aircraft deicing fluids rapid heating system is widely used in aircraft ground deicing to ensure that the operation of flights can be safe and efficient. Aiming at the temperature turbulence problem of aircraft deicing system, this paper presents the single neuron PID control strategy which combine the advantage of conventional PID control with artificial neuron control. The aircraft deicing fluids rapid heating system and the scheme and working principle of the system is introduced. Simulation is executed on the basis of the mathematical model of aircraft deicing fluids rapid heating system, which is built in this paper, according to a number of data collected by experiments which are operated on the experimental platform of deicing fluids rapid heating system. The simulation results show that the single neuron PID control strategy perform effectively on the temperature turbulence problem of aircraft deicing fluids rapid heating system. Experiments are conducted to vertify the single neuron PID control strategy, the results of which show that the single neuron PID control strategy can achieve the request in practical application of the aircraft deicing fluids rapid heating system.

Intelligent Control Method for Aircraft Deicing Fluidtemperature Based on a New Adaptive Smith Predictor

During the course of industry control, pure hysteresis, time-varying，non- linear complex systems often occur. It is ineffective to solve the issues above with the traditional fuzzy control and PID control methods. Against the pure hysteresis, time-varying, non- linear characteristics of Aircraft Deicing Fluid rapid heating system, on the basis of Smith Predictor and traditional PID, a Fuzzy-PID control method is proposed based on an adaptive Smith predictor. In this way, pure hysteresis of the system will be compensated, to reduce the overshoot and enhance the stability of the system. By establishing the mathematical model of Aircraft Deicing Fluid rapid heating system and simulating for the model obtain the simulation results, which have shown that the method is effective, can improve the qualities of control and enhance the stability of temperature control system significantly

Treatment of arsenic-contaminated groundwater by a low cost activated alumina adsorbent prepared by partial thermal dehydration

Experimental investigations were carried out to remove arsenic from contaminated groundwater by low cost activated alumina based adsorbent prepared by partial thermal dehydration. Activated alumina based adsorbent with high surface area was prepared following partial thermal dehydration of gibbsite precursor and an attempt was made to study the effects of dehydration temperature, residence time, rate of increase of temperature and particle size on development of active surface area of the adsorbent. The operating parameters were found to have significant effect on active surface area development. BET Surface area (by nitrogen adsorption) and ignition losses were determined for all the samples. It was found that an adsorbent of surface area of around 335–340 m2/g could be developed when dehydrated at 500°C for a residence time of 30 min in a rapid heating system (rate of increase of temperature 200°C/min) with particle size of 200 mesh (85%). The arsenic adsorption capacity of this adsorbent was determined both in batch and column studies. The adsorbent was found to be very effective in removing arsenic. The adsorbent placed in column could successfully remove arsenic from water up to a level below 10 µg/L for more than 6000 bed volume water.

Micro-injection molding with the infrared assisted mold heating system

Mold temperature and packing pressure are the major factors that affect the process of micro-molding. The mold temperature was found to be the crucial factor that controls the success of the complete filling. In micro-injection molding, the mold temperature has to be close to the glass temperature to ensure a good replication of the micro-features. This study is to investigate the effect of infrared mold surface rapid heating system on the micro-injection molding. The micro-feature was defined by the UV lithography technology and transfer to the nickel mold insert by micro-electroforming. An infrared heating system is designed and built to heat the mold surface dynamically. The infrared heating system raises the mold cavity temperature locally to facilitate the replication of the micro-structure. The results show that mold cavity surface must be heated to above a critical temperature before molding. The critical temperature is close to the glass transition temperature and it decreases with the increase of the packing pressure. For mold temperature in 80 °C, heating more than 10 s can result in a complete filling of the micro-feature used in this study.

Simulation of infrared rapid surface heating for injection molding

In this study, a three-dimension ray tracing and transient thermal simulation is developed to evaluate the thermal condition of injection mold surface with infrared surface rapid heating system. Several types of reflectors were applied to study the heating ability of the rapid surface heating system. A commercial available optical analysis program, TracePro, was used to simulate the infrared absorption of the mold surface. The surface temperature of the mold insert was evaluated by 2D and 3D transient thermal analysis with a commercial software, ANSYS. The results from simulation and thermal video measurement system agree well. Besides, the temperature distribution of the mold surface can be better observed via the 3D thermal analysis developed in this article.