Dispersion Number Identification in an Imbert Gasifier Under Parameter Uncertainty

2017 ◽  
Author(s):  
Luis Santamaria-Padilla ◽  
Luis Alvarez-Icaza ◽  
Jesus Alvarez
Keyword(s):  
Tubular Reactor ◽  
Temperature Response ◽  
Heat Pulse ◽  
Related Function ◽  
Pulse Input ◽  
Response Characteristics ◽  
Dispersion Mechanism ◽  
On Line ◽  
Heat Dispersion ◽  
Dispersion Number

The problem of identifying the dispersion number associated with the convective-radiative heat dispersion mechanism in an experimental gasification tubular reactor is addressed. The dependency of temperature response characteristics on the intensity and duration of a heat pulse input are characterized on the basis of a set of off-line experiments, finding that for the range of interest: (i) the coefficient of variation of the temporal temperature response depends almost linearly on the dispersion number, and (ii) the related function is robustly invertible with respect to model and experimental uncertainty. This results establishes the feasibility of identifying the key heat dispersion (inverse Peclet) number from a reasonable on-line heat pulse injection test.

Study on characteristics of schottky temperature detector based on metal/n-ZnO/n-Si structures

2020 ◽  
Vol 12 ◽  
Author(s):  
Fang Wang ◽  
Jingkai Wei ◽  
Caixia Guo ◽  
Tao Ma ◽  
Linqing Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Measurement ◽  
Temperature Response ◽  
Large Temperature ◽  
Mems Devices ◽  
Temperature Range ◽  
Response Characteristics ◽  
High Temperature Measurement ◽  
Temperature Detector ◽  
Schottky Structure

Background: At present, the main problems of Micro-Electro-Mechanical Systems (MEMS) temperature detector focus on the narrow range of temperature detection, difficulty of the high temperature measurement. Besides, MEMS devices have different response characteristics for various surrounding temperature in the petrochemical and metallurgy application fields with high-temperature and harsh conditions. To evaluate the performance stability of the hightemperature MEMS devices, the real-time temperature measurement is necessary. Objective: A schottky temperature detector based on the metal/n-ZnO/n-Si structures is designed to measure high temperature (523~873K) for the high-temperature MEMS devices with large temperature range. Method: By using the finite element method (FEM), three different work function metals (Cu, Ni and Pt) contact with the n-ZnO are investigated to realize Schottky. At room temperature (298K) and high temperature (523~873K), the current densities with various bias voltages (J-V) are studied. Results: The simulation results show that the high temperature response power consumption of three schottky detectors of Cu, Ni and Pt decreases successively, which are 1.16 mW, 63.63 μW and 0.14 μW. The response temperature sensitivities of 6.35 μA/K, 0.78 μA/K, and 2.29 nA/K are achieved. Conclusion: The Cu/n-ZnO/n-Si schottky structure could be used as a high temperature detector (523~873K) for the hightemperature MEMS devices. It has a large temperature range (350K) and a high response sensitivity is 6.35 μA/K. Compared with traditional devices, the Cu/n-ZnO/n-Si Schottky structure based temperature detector has a low energy consumption of 1.16 mW, which has potential applications in the high-temperature measurement of the MEMS devices.

The Determination of Flash Temperature in Intermittent Magnetic Head/Disk Contacts Using Magnetoresistive Heads: Part I—Model and Laser Simulation

1993 ◽  
Vol 115 (1) ◽  
pp. 170-178 ◽  
Author(s):  
Yufeng Li ◽  
Aric R. Kumaran
Keyword(s):  
Theoretical Model ◽  
Temperature Response ◽  
Sensitivity Coefficient ◽  
Flash Temperature ◽  
Magnetic Head ◽  
Response Characteristics ◽  
Power Intensity ◽  
Magnetoresistive Sensor ◽  
Laser Simulation ◽  
Magnetoresistive Heads

The feasibility of using a magnetoresistive magnetic head to determine the flash temperature of intermittent magnetic head/disk contacts is investigated. A finite difference model is developed to study the effects of the magnetoresistive sensor height, the contact power intensity and the contact duration on the temperature response characteristics of the magnetoresistive sensor. A pulsed neody-minum:yttrium-aluminum-garnet laser is used as the heat source to simulate the contact and verify the model. The simulation results agree well with the theoretical model. Based on the theoretical model and laser simulation, a temperature sensitivity coefficient ζ is proposed to determine the surface temperature rise.

Adaptive Generalized Predictive Control on Electro Hydraulic Servo Feeding System of Band Saw

2013 ◽  
Vol 433-435 ◽  
pp. 1947-1952 ◽  
Author(s):  
Jing Ni ◽  
Zhao Ning Xia
Keyword(s):  
Control Variable ◽  
System Control ◽  
Control Input ◽  
Feeding System ◽  
Response Characteristics ◽  
Hydraulic Servo ◽  
Simulation And Experiment ◽  
Predictive Controller ◽  
On Line ◽  
Band Saw

In view of the shortcomings of band saw feeding system on position and micro-feeding speed tracking response characteristics, an electro-hydraulic servo feeding system of band saw is designed and its difference mathematical model is presented. Then, a new adaptive generalized predictive controller (AGPC) for the electro-hydraulic servo feeding system is provided. The controller identifies the parameters of the system model by system control input and output on line. Through minimizing performance evaluation function J which is based on j-step ahead predictive output of CARIMA model, system control variable can be got. The simulation and experiment application show that the proposed controller has better position precision and feeding tracking performances than the traditional PID controller and can well address feeding process of band saw.

New Planar Disc Transient Method for the Measurement of Thermal Properties of Materials

2015 ◽  
Vol 1126 ◽  
pp. 16-21 ◽  
Author(s):  
Vlastimil Boháč ◽  
Peter Dieška ◽  
Viliam Vretenár ◽  
Danica Opatt-Fidríková ◽  
Vladimír Štofanik ◽  
...  
Keyword(s):  
Temperature Field ◽  
Signal To Noise Ratio ◽  
Temperature Response ◽  
Heat Pulse ◽  
Cylindrical Sample ◽  
Outer Radius ◽  
Infinite Length ◽  
Additional Parameter ◽  
Temperature Function ◽  
Single Transition

Recently the physical model for the temperature field generated by thermophysical single-probe sensor in a shape of planar disc has been derived. The model accounts cylindrical sample having final radius and infinite length. The prototype of measuring electronics RTA was build that operates with auto balancing bridge. For the measurements the single-transition method is used. While the measurement error of the temperature response measured by thermocouple was 1% at the height of temperature response 1°C, the sensitivity of the measurement with the automatically balanced bridge is better and the signal to noise ratio is improved about 10 times. The measuring electronics was tested for measuring the temperature response using a single-sensor. This sensor generates the heat pulse and sense the temperature response in the same time. The next advantage is that the temperature response to the generated step-wise pulse is much smaller and it can be reduced to the level of 1-8° C compared to stationary method like guarded hot plate method. The effect of the temperature field generated by the probe is much smaller, which in the case of measurement of porous materials at the presence of moisture is beneficial, as the resulting redistribution of moisture under the created temperature gradient is negligible. There were derived basic models for the evaluation of this type of experiment. The probe should be in form of full cylinder or an annulus. The derived temperature function counts the outer and inner diameter of annulus. Putting the inner radius to zero we get the solution for full circle probe, so the model is universal. The model counts also the heat losses from the outer surface of the sample, when the time of measurement exceed the time when the penetration depth of generated heat pulse rich the outer radius of sample. The estimated output parameters from single measurement are the thermal conductivity, thermal diffusivity and specific heat. The heat transfer coefficient is additional parameter fitted as free parameter of the model.

scholarly journals Active heat pulse sensing of 3-D-flow fields in streambeds

2018 ◽  
Vol 22 (3) ◽  
pp. 1917-1929 ◽  
Author(s):  
Eddie W. Banks ◽  
Margaret A. Shanafield ◽  
Saskia Noorduijn ◽  
James McCallum ◽  
Jörg Lewandowski ◽  
...  
Keyword(s):  
Hyporheic Zone ◽  
Flow Direction ◽  
Temperature Response ◽  
Past Research ◽  
Flow Patterns ◽  
Heat Pulse ◽  
Breakthrough Curves ◽  
Hyporheic Flow ◽  
Heat Pulses ◽  
Streambed Sediments

Abstract. Profiles of temperature time series are commonly used to determine hyporheic flow patterns and hydraulic dynamics in the streambed sediments. Although hyporheic flows are 3-D, past research has focused on determining the magnitude of the vertical flow component and how this varies spatially. This study used a portable 56-sensor, 3-D temperature array with three heat pulse sources to measure the flow direction and magnitude up to 200 mm below the water–sediment interface. Short, 1 min heat pulses were injected at one of the three heat sources and the temperature response was monitored over a period of 30 min. Breakthrough curves from each of the sensors were analysed using a heat transport equation. Parameter estimation and uncertainty analysis was undertaken using the differential evolution adaptive metropolis (DREAM) algorithm, an adaption of the Markov chain Monte Carlo method, to estimate the flux and its orientation. Measurements were conducted in the field and in a sand tank under an extensive range of controlled hydraulic conditions to validate the method. The use of short-duration heat pulses provided a rapid, accurate assessment technique for determining dynamic and multi-directional flow patterns in the hyporheic zone and is a basis for improved understanding of biogeochemical processes at the water–streambed interface.

scholarly journals Active heat pulse sensing of 3D-flow fields in streambeds

2017 ◽  
Author(s):  
Eddie W. Banks ◽  
Margaret A. Shanafield ◽  
Saskia Noorduijn ◽  
James McCallum ◽  
Jörg Lewandowski ◽  
...  
Keyword(s):  
Hyporheic Zone ◽  
Flow Direction ◽  
Temperature Response ◽  
Past Research ◽  
Flow Patterns ◽  
Heat Pulse ◽  
Breakthrough Curves ◽  
Hyporheic Flow ◽  
Heat Pulses ◽  
Streambed Sediments

Abstract. Profiles of temperature time series are commonly used to determine hyporheic flow patterns and hydraulic dynamics in the streambed sediments. Although hyporheic flows are 3D, past research has focused on determining the magnitude of the vertical flow component and how this varies spatially. This study used a portable 56 sensor, 3D temperature array with 3 heat pulse sources to measure the flow direction and magnitude up to 200 mm below the water-sediment interface. Short, one-minute heat pulses were injected at one of the three heat sources and the temperature response was monitored over a period of 30 minutes. Breakthrough curves from each of the sensors were analyzed using a heat transport equation. Parameter estimation and uncertainty analysis was undertaken using the DREAM algorithm, an adaption of the Markov chain Monte Carlo method, to estimate the flux and its orientation. Measurements were conducted in the field and in a sand tank under an extensive range of controlled hydraulic conditions to validate the method. The use of short duration heat pulses provided a rapid, accurate assessment technique for determining dynamic and multi-directional flow patterns in the hyporheic zone and is a basis for improved understanding of biogeochemical processes at the water-streambed interface.

scholarly journals Experimental Study on Temperature Response Characteristics of Water-bearing Rock Mass during Mining

2013 ◽  
Vol 129 (7) ◽  
pp. 506-512
Author(s):  
Yang GAO ◽  
Yujing JIANG ◽  
Qingsong ZHANG ◽  
Bo LI ◽  
Lei YANG
Keyword(s):  
Experimental Study ◽  
Rock Mass ◽  
Temperature Response ◽  
Response Characteristics

scholarly journals Temperature response characteristics of enzyme thermistor using precisely thermostated bath.

1988 ◽  
Vol 14 (5) ◽  
pp. 695-698
Author(s):  
Noriaki Kaneki ◽  
Hiromitsu Sakai ◽  
Kennosuke Yokota ◽  
Takao Takeuchi ◽  
Koji Shimada ◽  
...  
Keyword(s):  
Temperature Response ◽  
Response Characteristics ◽  
Enzyme Thermistor
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