scholarly journals In situ measurement and closed-loop control for powder supply processes

2021 ◽  
Author(s):  
Philipp Peter Breese ◽  
Tobias Hauser ◽  
Daniel Regulin ◽  
Stefan Seebauer ◽  
Christian Rupprecht
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Closed Loop ◽  
In Situ Measurement ◽  
Closed Loop Control ◽  
Loop Control ◽  
Powder Feeder ◽  
Powder Mass

AbstractThe powder mass flow rate is one of the main parameters regarding the geometrical precision of built components in the additive manufacturing process of laser metal deposition. However, its accuracy, constancy, and repeatability over the course of the running process is not given. Reasons among others are the performance of the powder conveyors, the complex nature of the powder behavior, and the resulting issues with existing closed-loop control approaches. Additionally, a direct in situ measurement of the powder mass flow rate is only possible with intrusive methods. This publication introduces a novel approach to measure the current powder mass flow rate at a frequency of 125 Hz. The volumetric powder flow evaluation given by a simple optical sensor concept was transferred to a mass flow rate through mathematical dependencies. They were found experimentally for a nickel-based powder (Inconel 625) and are valid for a wide range of mass flow rates. With this, the dynamic behavior of a vibration powder feeder was investigated and a memory effect dependent on previous powder feeder speeds was discovered. Next, a closed-loop control with the received sensor signal was implemented. The concept as a whole gives a repeatable and accurate powder mass flow rate while being universally retrofittable and applicable. In a final step, the improved dynamic and steady performance of the powder mass flow rate with closed-loop control was validated. It showed a reduction of mean relative errors for step responses of up to 81% compared to the uncontrolled cases.

scholarly journals Modelling an unconventional closed-loop deep borehole heat exchanger (DBHE): sensitivity analysis on the Newberry volcanic setting

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Hannah R. Doran ◽  
Theo Renaud ◽  
Gioia Falcone ◽  
Lehua Pan ◽  
Patrick G. Verdin
Keyword(s):  
Sensitivity Analysis ◽  
Heat Exchanger ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Energy Flow ◽  
Closed Loop ◽  
Working Fluid ◽  
Valuable Insight ◽  
Deep Borehole

AbstractAlternative (unconventional) deep geothermal designs are needed to provide a secure and efficient geothermal energy supply. An in-depth sensitivity analysis was investigated considering a deep borehole closed-loop heat exchanger (DBHE) to overcome the current limitations of deep EGS. A T2Well/EOS1 model previously calibrated on an experimental DBHE in Hawaii was adapted to the current NWG 55-29 well at the Newberry volcano site in Central Oregon. A sensitivity analysis was carried out, including parameters such as the working fluid mass flow rate, the casing and cement thermal properties, and the wellbore radii dimensions. The results conclude the highest energy flow rate to be 1.5 MW, after an annulus radii increase and an imposed mass flow rate of 5 kg/s. At 3 kg/s, the DBHE yielded an energy flow rate a factor of 3.5 lower than the NWG 55-29 conventional design. Despite this loss, the sensitivity analysis allows an assessment of the key thermodynamics within the wellbore and provides a valuable insight into how heat is lost/gained throughout the system. This analysis was performed under the assumption of subcritical conditions, and could aid the development of unconventional designs within future EGS work like the Newberry Deep Drilling Project (NDDP). Requirements for further software development are briefly discussed, which would facilitate the modelling of unconventional geothermal wells in supercritical systems to support EGS projects that could extend to deeper depths.

Research on Powder Stream of Coaxial Powder Feeding in Laser Manufacturing Technology

2013 ◽  
Vol 423-426 ◽  
pp. 807-810
Author(s):  
Heng Quan ◽  
Yun Shan Wang ◽  
Li Feng Liu ◽  
Shao Jun Liu ◽  
Qing Ruo Meng
Keyword(s):  
Physical Model ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Concentration Field ◽  
Ccd Camera ◽  
Factors Affecting ◽  
Coaxial Nozzle ◽  
Powder Mass ◽  
Powder Feeding

Mathematical-physical model of powder stream in coaxial powder feeding was established. The concentration fields of powder stream of coaxial nozzle of different size and powder mass flow rate were analyzed. The concentration field and morphology of the powder stream were detected by CCD camera. The results show that the size of coaxial nozzle and powder mass flow rate are major factors affecting the powder stream. The mathematical-physical model and experimental data provide theoretical basis for laser cladding manufacturing.

scholarly journals An Intelligent Multi-Sensor Variable Spray System with Chaotic Optimization and Adaptive Fuzzy Control

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2954 ◽  
Author(s):  
Lepeng Song ◽  
Jinpen Huang ◽  
Xianwen Liang ◽  
Simon X. Yang ◽  
Wenjin Hu ◽  
...  
Keyword(s):  
Control System ◽  
Flow Rate ◽  
Rise Time ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Loop Control ◽  
Adaptive Fuzzy ◽  
Spray System ◽  
Adjustment Time ◽  
Spray Droplets

During the variable spray process, the micro-flow control is often held back by such problems as low initial sensitivity, large inertia, large hysteresis, nonlinearity as well as the inevitable difficulties in controlling the size of the variable spray droplets. In this paper, a novel intelligent double closed-loop control with chaotic optimization and adaptive fuzzy logic is developed for a multi-sensor based variable spray system, where a Bang-Bang relay controller is used to speed up the system operation, and adaptive fuzzy nonlinear PID is employed to improve the accuracy and stability of the system. With the chaotic optimization of controller parameters, the system is globally optimized in the whole solution space. By applying the proposed double closed-loop control, the variable pressure control system includes the pressure system as the inner closed-loop and the spray volume system as the outer closed-loop. Thus, the maximum amount of spray droplets deposited on the plant surface may be achieved with the minimum medicine usage for plants. Multiple sensors (for example: three pressure sensors and two flow rate sensors) are employed to measure the system states. Simulation results show that the chaotic optimized controller has a rise time of 0.9 s, along with an adjustment time of 1.5 s and a maximum overshoot of 2.67% (in comparison using PID, the rise time is 2.2 s, the adjustment time is 5 s, and the maximum overshoot is 6.0%). The optimized controller parameters are programmed into the hardware to control the established variable spray system. The experimental results show that the optimal spray pressure of the spray system is approximately 0.3 MPa, and the flow rate is approximately 0.08 m3/h. The effective droplet rate is 89.4%, in comparison to 81.3% using the conventional PID control. The proposed chaotically optimized composite controller significantly improved the dynamic performance of the control system, and satisfactory control results are achieved.

scholarly journals Influence of rubber powder mass flow rate on process of plasma pyrolysis

2019 ◽  
Author(s):  
Jarosław Szuszkiewicz
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Chemical Compounds ◽  
Plasma Generator ◽  
Arc Plasma ◽  
Rubber Powder ◽  
Gaseous Products ◽  
Powder Mass ◽  
Plasma Pyrolysis

The paper describes the experimental examination of thermal utilization of used rubber. The research was carried out to examine the influence of rubber powder mass flow rate on the process of plasma pyrolysis of rubber. An arc plasma generator has been applied. Ar and mixture of Ar and H2 were used as plasma gas. The analysis of composition of the gaseous products was done by the infrared absorption spectroscopy. All the rubber introduced to the plasma jet was decomposed. The outgoing gas did not contain any of toxic chemical compounds, like NOx or HCN.

The Application of PLC in the Stepper Motor Closed-Loop Control System Design

2012 ◽  
Vol 605-607 ◽  
pp. 1537-1540 ◽  
Author(s):  
Xiao Yu Wang
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Low Cost ◽  
Stepper Motor ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
System Flow ◽  
Loop Control System

The application of PLC 、Stepper motor driver and Encoder are introduced in stepper motor closed-loop control system. The Principle diagram is analyzed, the Control System flow chart and Software program are designed. Through in-situ operation, the system has been proved well reliability、 stability and simplicity , achieved high accuracy and low cost requirements。

scholarly journals Digital Measurement of Powder Mass Flow Rate

1974 ◽  
Vol 11 (7) ◽  
pp. 413-417
Author(s):  
Yukio Nishimi ◽  
Tadaharu Onishi ◽  
Takeshi Katsura ◽  
Ikuo Enokiya
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Digital Measurement ◽  
Powder Mass
Sign in / Sign up

Export Citation Format

Share Document