In the Ruhrstahl-Heraeus （RH） refining process, liquid steel flow pattern in a ladle is controlled by the fluid flow behavior in the vacuum chamber. Potassium chloride solution and NaOH solution saturated with CO2 w...In the Ruhrstahl-Heraeus （RH） refining process, liquid steel flow pattern in a ladle is controlled by the fluid flow behavior in the vacuum chamber. Potassium chloride solution and NaOH solution saturated with CO2 were respectively used as a tracer to investigate the liquid and gas flow behaviors in the vacuum chamber. Principal compo nent and comparative analysis were made to show the factors controlling mixing and circulation flow rate. The liquid level and bubble behavior in the vacuum chamber greatly affect fluid flow in RH process. Experiments were performed to investigate the effects of liquid steel level, gas flow rate, bubble residence time, and gas injection mode on mixing, decarburization, and void fraction. The results indicate that the mixing process can be divided into three regions： the flow rate affected zone, the concentration gradient-affected zone, and their combination. The liquid steel level in the vacuum chamber of 300 mm is a critical point in the decarburization transition. For liquid level lower than 300 mm, liquid steel circulation controls decarburization, while for liquid level higher than 300mm, bubble behavior is the main controlling factor. During the RH process, it is recommended to use the concentrated bubble injection mode for low gas flow rates and the uniform bubble injection mode for high gas flow rates.展开更多
In the production of the sucker rod well, the dynamic liquid level is important for the production efficiency and safety in the lifting process. It is influenced by multi-source data which need to be combined for the ...In the production of the sucker rod well, the dynamic liquid level is important for the production efficiency and safety in the lifting process. It is influenced by multi-source data which need to be combined for the dynamic liquid level real-time calculation. In this paper, the multi-source data are regarded as the different views including the load of the sucker rod and liquid in the wellbore, the image of the dynamometer card and production dynamics parameters. These views can be fused by the multi-branch neural network with special fusion layer. With this method, the features of different views can be extracted by considering the difference of the modality and physical meaning between them. Then, the extraction results which are selected by multinomial sampling can be the input of the fusion layer.During the fusion process, the availability under different views determines whether the views are fused in the fusion layer or not. In this way, not only the correlation between the views can be considered, but also the missing data can be processed automatically. The results have shown that the load and production features fusion(the method proposed in this paper) performs best with the lowest mean absolute error(MAE) 39.63 m, followed by the features concatenation with MAE 42.47 m. They both performed better than only a single view and the lower MAE of the features fusion indicates that its generalization ability is stronger. In contrast, the image feature as a single view contributes little to the accuracy improvement after fused with other views with the highest MAE. When there is data missing in some view, compared with the features concatenation, the multi-view features fusion will not result in the unavailability of a large number of samples. When the missing rate is 10%, 30%, 50% and 80%, the method proposed in this paper can reduce MAE by 5.8, 7, 9.3 and 20.3 m respectively. In general, the multi-view features fusion method proposed in this paper can improve the accuracy obviously and process the missing data effectively, which helps provide technical support for real-time monitoring of the dynamic liquid level in oil fields.展开更多
In this paper, a new analysis and design method for proportional-integrative-derivative （PID） tuning is proposed based on controller scaling analysis. Integral of time absolute error （ITAE） index is minimized for ...In this paper, a new analysis and design method for proportional-integrative-derivative （PID） tuning is proposed based on controller scaling analysis. Integral of time absolute error （ITAE） index is minimized for specified gain and phase margins （GPM） constraints, so that the transient performance and robustness are both satisfied. The requirements on gain and phase margins are ingeniously formulated by real part constraints （RPC） and imaginary part constraints （IPC）. This set of new constraints is simply related with three parameters and decoupling of the remaining four unknowns, including three controller parameters and the gain margin, in the nonlinear and coupled characteristic equation simultaneously. The formulas of the optimal GPM-PID are derived based on controller scaling analysis. Finally, this method is applied to liquid level control of coke fractionation tower, which demonstrate that the proposed method provides better disturbance rejection and robust tracking performance than some commonly used PID tuning methods.展开更多
This paper describes the design and development of the timer based on liquid level measurement system in which timer 555 is used in astable mode. The capacitor charging time i. e. the ON time pulse width of the ti...This paper describes the design and development of the timer based on liquid level measurement system in which timer 555 is used in astable mode. The capacitor charging time i. e. the ON time pulse width of the timer output waveform which is measured using a digital storage oscillator （DSO）,is linearly proportional to the capacitance of a co-axial cylindrical capacitive transducer, and this capacitance once again linearly varies with the change in liquid level. Hence, we obtain a linear relationship between the liquid level and the capacitor charging time. The main advantages of this developed system are linear input-output relationship, small in size, easily portable, cost effective, and independent on the ambient temperature effect. The system can also be exploited to measure dielectric constant of liquid or solid in various process industries.展开更多
This paper introduced the components, principle and the hardware and software design of the multiplexing measuring and control instrument to the liquid level that is based on MSP430 SCM. This system is made of pressur...This paper introduced the components, principle and the hardware and software design of the multiplexing measuring and control instrument to the liquid level that is based on MSP430 SCM. This system is made of pressure sensor, signal processing circuit, electromagnetic valve, output driving circuit, Chinese character LCD, keyboard, optic alarm circuit and MSP430MCU, and realized Liquid level automatic monitor, out range alarm and online function.展开更多
The magnetostrictive liquid level transmitter of offshore platform is mainly used to measure the liquid level height in each tank in the process flow, which has very important value in specific use. Because of the com...The magnetostrictive liquid level transmitter of offshore platform is mainly used to measure the liquid level height in each tank in the process flow, which has very important value in specific use. Because of the complicated offshore environment, magnetostrictive liquid level transmitter is prone to problems. Once there is a jump, it must be resolved in time to ensure the normal operation of the equipment. This paper introduces the problems and solutions of using magnetostrictive liquid level transducer under the vibration condition of offshore oil platforms. This paper mainly introduces the working principle of magnetostrictive liquid level transducer, analyzes the causes of the "signal jump" problem, and puts forward the proposed solutions.展开更多
In this paper, a new wireless measuring method for colorless liquid level measurement was presented, based on latest CLC100 liquid level sensor and Powercast wireless sensor development kit. The wireless system is div...In this paper, a new wireless measuring method for colorless liquid level measurement was presented, based on latest CLC100 liquid level sensor and Powercast wireless sensor development kit. The wireless system is divided into two parts, level measurement and data transmission part as well as data receiving and display part. First part included the capacitive liquid level sensor CLC100 and the wireless senor board. CLC100 sensor was used for liquid level measurement. Wireless sensor kit from Powercast Corporation included one wireless sensor board, which was used for signal transmission. A built-in PIC microcontroller was embedded in the transmission module, for the purpose of processing and data transmitting. Due to CLC100 sensor’s output voltage exceeding the sensor board’s input limitation, a voltage convertor was designed to connect the sensor and the wireless sensor board. The final results were voltages corresponding to the liquid level, and were processed by an independent PIC development board, and then sent to PC’s hyper terminal via serial-port by this PIC microcontroller. Experiments showed that this wireless sensor node prototype worked well.展开更多
The work describes a surface plasmon resonance(SPR)sensor that measures the liquid level and refractive index(RI)simultaneously.The sensor is fabricated by a polymer optical fiber(POF)with a side-polished spiral struc...The work describes a surface plasmon resonance(SPR)sensor that measures the liquid level and refractive index(RI)simultaneously.The sensor is fabricated by a polymer optical fiber(POF)with a side-polished spiral structure.The POF is wound around a plastic rod with the same pitch and polished into a series of separated side-polished areas to form the sensor probe.Afterwards,the polished surfaces are coated with a gold layer to construct the SPR sensor.The proposed sensor can provide multi-point liquid-level measurement besides RI sensing.The influences of structural parameters such as the bending radius,polishing depth,and pitch on the sensing performance are experimentally studied.The experimental results indicate that the RI could be determined by employing the SPR wavelength shift,and the RI sensitivity of 1862 nm/RIU within the 1.34–1.40 range is obtained.Moreover,the SPR peak’s depth variation can be utilized to monitor the liquid level,and the sensor can provide adjustable resolution and a measurement range for liquid level sensing.With its simple fabrication,low cost,and flexible sensing ability,this sensor probe is suitable for the usage in biochemical applications.展开更多
The solid-liquid mixing is an important operation unit in the preparation of composites by stirring casting.High quality composite materials need good homogeneity and stable liquid level.In this work,the performances ...The solid-liquid mixing is an important operation unit in the preparation of composites by stirring casting.High quality composite materials need good homogeneity and stable liquid level.In this work,the performances of the Rotor-Stator agitator for solid suspension in stirred tank were investigated through CFD modeling,including the homogeneity,power consumption and liquid level stability.The Eulerian-Eulerian(E-E)multiphase model and the RNG k-εturbulence model were adopted for modeling the multiphase flow and the turbulence effects,respectively.The effect of various important parameters such as stirring speed,particle size,solid loading and the use of baffles were examined.Adding a stator structure with array holes outside the rotor can optimize the flow pattern,thereby improving the mixing uniformity and liquid level stability.The homogeneity and liquid level stability attained by the Rotor-Stator agitator were better than those for the A200(an axial-flow agitator)and the Rushton(a radial-flow agitator).展开更多
Self-powered sensors are highly sought for wireless sensing applications in space exploration,industries,and environmental monitoring,etc.However,most current self-powered sensor technologies are based on the multiple...Self-powered sensors are highly sought for wireless sensing applications in space exploration,industries,and environmental monitoring,etc.However,most current self-powered sensor technologies are based on the multiple energy conversion routine:energy collection,rectification,energy storage,and power management before it can be used for sensor systems,leading to exceptionally low energy utilization efficiency and very short periods of wireless sensing operation with majority of information lost.Here,we propose a triboelectric nanogenerator(TENG)based fully self-powered instantaneous and real-time wireless sensor system which does not contain electronic devices and microchips,but the passive components only.An innovative cylindrical capacitive-type liquid level sensor is also proposed and is then integrated into the wireless sensor system for monitoring liquid levels or identifying substance of the liquids.This sensor system can convert pulsed voltage output of the TENG into sinusoidal signal with a resonant frequency containing the sensing information and is transmitted to the receiver in distance in real-time.The maximum transmission distance of the sensor system could reach 1.5 m for a 10 cm diameter magnetic-core coil pair.The wireless sensor system exhibited excellent stability and excellent linearity with a sensitivity of 4.63 kHz/cm,and demonstrated its great application potential for the self-powered liquid level monitoring.展开更多
In this paper,a novel liquid level sensor with ultra-high sensitivity is proposed.The proposed sensor is configured by a sliceshaped composite long period fiber grating(SSC-LPFG).The SSC-LPFG is prepared by polishing ...In this paper,a novel liquid level sensor with ultra-high sensitivity is proposed.The proposed sensor is configured by a sliceshaped composite long period fiber grating(SSC-LPFG).The SSC-LPFG is prepared by polishing two opposite sides of a composite multimode-single-mode-multimode fiber structure using a CO;laser.The method improves the sensitivity of the sensor to external environment.Based on the simulation calculation,a liquid level sensor with a length of 3 mm is designed.The experimental transmission spectrum agrees well with the simulation result.The experimental results show that the sensitivity reaches 7080 pm/mm in the liquid level range of 0-1400 μm in water.The temperature sensitivity is24.52 pm/℃ in the range of 20℃-90℃.Due to the ultra-high sensitivity,good linearity,and compact structure,the SSC-LPFG has potential application in the field of high-Drecision liquid level measurement.展开更多
The two-phase xenon detector is at the frontier of dark matter direct search. This kind of detector uses liquid xenon as the sensitive target and is operated in two-phase （liquid/gas） mode, where the liquid level ne...The two-phase xenon detector is at the frontier of dark matter direct search. This kind of detector uses liquid xenon as the sensitive target and is operated in two-phase （liquid/gas） mode, where the liquid level needs to be monitored and controlled in sub-millimeter precision. In this paper, we present a detailed design and study of two kinds of level meters for the PandaX dark matter detector. The long level meter is used to monitor the overall liquid level while short level meters are used to monitor the inclination of the detector. These level meters are cylindrical capacitors that are custom-made from two concentric metal tubes. Their capacitance values are read out by a universal transducer interface chip and are recorded by the PandaX slow control system. We present the developments that lead to level meters with long-term stability and sub-millimeter precision. Fluctuations （standard deviations） of less than 0.02 mm for the short level meters and less than 0.2 mm for the long level meter were achieved during a few days of test operation.展开更多
A novel fiber optic liquid level sensor based on laser radar (ladar) is reported here. Using the perfect technique of ladar in which the phase of amplitude modulated light wave reflected from the liquid surface is com...A novel fiber optic liquid level sensor based on laser radar (ladar) is reported here. Using the perfect technique of ladar in which the phase of amplitude modulated light wave reflected from the liquid surface is compared with that of original modulation signal, the distance can be measured precisely. A special symmetric compensating coaxial optical system is proposed to eliminate many adverse effects. It realized the one-time electronic-free optical measurement on a simulated oil tank and achieves an accuracy of 0.3%, within a temperature range of -10 ℃～+40 ℃ over a measuring of 0～10 m.展开更多
Many kinds of high temperature superconductor （HTS） power machines such as HTS cable, HTS fault current limitcr and HTS magnet are cooled by liquid nitrogen. The level of liquid nitrogen should be monitored and cont...Many kinds of high temperature superconductor （HTS） power machines such as HTS cable, HTS fault current limitcr and HTS magnet are cooled by liquid nitrogen. The level of liquid nitrogen should be monitored and controlled to ensure the thermal stability and the dielectric strength as well. To measure the level, capacitance method and differential pressure method are usually used. However, each method has installation difficulties and measurement errors for unsteady state operation with varying system pressure. A new liquid level meter using a 2G HTS conductor is described, which has similar structure with the liquid helium level meter with NbTi filament. The level meter is fabricated with a parallel connected heater, which helps the separation of the superconducting region and normal region, considering the critical temperature, large heat capacity of conductor and cooling characteristics. The level of liquid nitrogen can be obtained from the measured voltage signal along the 2G HTS conductor. Design, fabrication and test results of the new liquid nitrogen level meter are presented.展开更多
Utilizing the technology of Ultrasonic wave,relevant test arithmetic and the PC to carry on monitoring,controlling and cen-tralized management of the liquid-level in the liquid container. It can prevent from keeping i...Utilizing the technology of Ultrasonic wave,relevant test arithmetic and the PC to carry on monitoring,controlling and cen-tralized management of the liquid-level in the liquid container. It can prevent from keeping in touch with the examined liquid,not only has increased the continuous working time of the system greatly,simplifying maintenance of the sensor conveniently,can also realize overhauling in producing and boost the productivity and management level. The working principle,hardware structure of the instrument and the design method are presented,and the selection of sensor and MCU is discussed in detail in this paper. MCU are used to control the emission and receiving. Then the liquid-level are calculated,which makes the design more intelligent.展开更多
Basic properties of a silica-based octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) extraction resin (CMPO/SiO2-P) was investigated.Adsorption behavior for some rare earth elements (RE) which are con...Basic properties of a silica-based octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) extraction resin (CMPO/SiO2-P) was investigated.Adsorption behavior for some rare earth elements (RE) which are constituents of high level liquid waste (HLLW) and the long-term stability of the extraction resin in nitric acid solution were examined.The CMPO extraction resin was significantly stable in 3 mol·L?1 HNO3 solution at 50oC.Furthermore,the RE(III) were efficiently separated from non-adsorptive fission product (FP) elements such as Sr(II) in a column experiment using a highly nitric acid solution.The separation behaviors of the elements are considered to result from the difference in their adsorption and elution selectivity based on the complex formation with CMPO.There was no strong dependency of RE(III) separation efficiency on feed solution flow rate.Only from the perspectives of the acid-resistant behavior of CMPO extraction resin and the elution kinetics for the metal ions with the extraction resin,the CMPO extraction resin can be used in the modified MAREC process for HLLW partitioning.展开更多
The radar echo signal of non-stationary and singular points usually contains false echoes,which affects the recognition and measurement of liquid level echo signal.In order to eliminate false echo interference and imp...The radar echo signal of non-stationary and singular points usually contains false echoes,which affects the recognition and measurement of liquid level echo signal.In order to eliminate false echo interference and improve the recognition and measurement accuracy of the liquid level gauge,a method of echo recognition and correction based on adaptive least mean square(LMS)is proposed.The short-time amplitude function and short-time zero crossing rate function are combined to recognize the echo signal.The weight vector iteration and updating weight coefficients are obtained by LMS method.The echo signal is recognized and the false echo interference is suppressed.The experimental results show that the level echo signal can be accurately recognized by this method,and level measurement accuracy can reach0.47%F.S.Compared with other denoising methods,adaptive LMS can keep the signal singularity characteristics while suppressing the noise.Moreover,it has better robustness.展开更多
基金Item Sponsored by National Natural Science Foundation of China(51404022)Doctoral Fund of Ministry of Education of China(20130006110023)Ph.D Early Development Program of Taiyuan University of Science and Technology of China(20152008,20142001)
文摘In the Ruhrstahl-Heraeus （RH） refining process, liquid steel flow pattern in a ladle is controlled by the fluid flow behavior in the vacuum chamber. Potassium chloride solution and NaOH solution saturated with CO2 were respectively used as a tracer to investigate the liquid and gas flow behaviors in the vacuum chamber. Principal compo nent and comparative analysis were made to show the factors controlling mixing and circulation flow rate. The liquid level and bubble behavior in the vacuum chamber greatly affect fluid flow in RH process. Experiments were performed to investigate the effects of liquid steel level, gas flow rate, bubble residence time, and gas injection mode on mixing, decarburization, and void fraction. The results indicate that the mixing process can be divided into three regions： the flow rate affected zone, the concentration gradient-affected zone, and their combination. The liquid steel level in the vacuum chamber of 300 mm is a critical point in the decarburization transition. For liquid level lower than 300 mm, liquid steel circulation controls decarburization, while for liquid level higher than 300mm, bubble behavior is the main controlling factor. During the RH process, it is recommended to use the concentrated bubble injection mode for low gas flow rates and the uniform bubble injection mode for high gas flow rates.
基金supported by the National Natural Science Foundation of China under Grant 52325402, 52274057, 52074340 and 51874335the National Key R&D Program of China under Grant 2023YFB4104200+1 种基金the Major Scientific and Technological Projects of CNOOC under Grant CCL2022RCPS0397RSN111 Project under Grant B08028。
文摘In the production of the sucker rod well, the dynamic liquid level is important for the production efficiency and safety in the lifting process. It is influenced by multi-source data which need to be combined for the dynamic liquid level real-time calculation. In this paper, the multi-source data are regarded as the different views including the load of the sucker rod and liquid in the wellbore, the image of the dynamometer card and production dynamics parameters. These views can be fused by the multi-branch neural network with special fusion layer. With this method, the features of different views can be extracted by considering the difference of the modality and physical meaning between them. Then, the extraction results which are selected by multinomial sampling can be the input of the fusion layer.During the fusion process, the availability under different views determines whether the views are fused in the fusion layer or not. In this way, not only the correlation between the views can be considered, but also the missing data can be processed automatically. The results have shown that the load and production features fusion(the method proposed in this paper) performs best with the lowest mean absolute error(MAE) 39.63 m, followed by the features concatenation with MAE 42.47 m. They both performed better than only a single view and the lower MAE of the features fusion indicates that its generalization ability is stronger. In contrast, the image feature as a single view contributes little to the accuracy improvement after fused with other views with the highest MAE. When there is data missing in some view, compared with the features concatenation, the multi-view features fusion will not result in the unavailability of a large number of samples. When the missing rate is 10%, 30%, 50% and 80%, the method proposed in this paper can reduce MAE by 5.8, 7, 9.3 and 20.3 m respectively. In general, the multi-view features fusion method proposed in this paper can improve the accuracy obviously and process the missing data effectively, which helps provide technical support for real-time monitoring of the dynamic liquid level in oil fields.
基金supported by National Natural Science Foundation of China(Nos.61403149 and 61273069)Natural Science Foundation of Fujian Province(No.2015J01261)the Scientific Research Foundation of National Huaqiao University
文摘In this paper, a new analysis and design method for proportional-integrative-derivative （PID） tuning is proposed based on controller scaling analysis. Integral of time absolute error （ITAE） index is minimized for specified gain and phase margins （GPM） constraints, so that the transient performance and robustness are both satisfied. The requirements on gain and phase margins are ingeniously formulated by real part constraints （RPC） and imaginary part constraints （IPC）. This set of new constraints is simply related with three parameters and decoupling of the remaining four unknowns, including three controller parameters and the gain margin, in the nonlinear and coupled characteristic equation simultaneously. The formulas of the optimal GPM-PID are derived based on controller scaling analysis. Finally, this method is applied to liquid level control of coke fractionation tower, which demonstrate that the proposed method provides better disturbance rejection and robust tracking performance than some commonly used PID tuning methods.
文摘This paper describes the design and development of the timer based on liquid level measurement system in which timer 555 is used in astable mode. The capacitor charging time i. e. the ON time pulse width of the timer output waveform which is measured using a digital storage oscillator （DSO）,is linearly proportional to the capacitance of a co-axial cylindrical capacitive transducer, and this capacitance once again linearly varies with the change in liquid level. Hence, we obtain a linear relationship between the liquid level and the capacitor charging time. The main advantages of this developed system are linear input-output relationship, small in size, easily portable, cost effective, and independent on the ambient temperature effect. The system can also be exploited to measure dielectric constant of liquid or solid in various process industries.
文摘This paper introduced the components, principle and the hardware and software design of the multiplexing measuring and control instrument to the liquid level that is based on MSP430 SCM. This system is made of pressure sensor, signal processing circuit, electromagnetic valve, output driving circuit, Chinese character LCD, keyboard, optic alarm circuit and MSP430MCU, and realized Liquid level automatic monitor, out range alarm and online function.
文摘The magnetostrictive liquid level transmitter of offshore platform is mainly used to measure the liquid level height in each tank in the process flow, which has very important value in specific use. Because of the complicated offshore environment, magnetostrictive liquid level transmitter is prone to problems. Once there is a jump, it must be resolved in time to ensure the normal operation of the equipment. This paper introduces the problems and solutions of using magnetostrictive liquid level transducer under the vibration condition of offshore oil platforms. This paper mainly introduces the working principle of magnetostrictive liquid level transducer, analyzes the causes of the "signal jump" problem, and puts forward the proposed solutions.
文摘In this paper, a new wireless measuring method for colorless liquid level measurement was presented, based on latest CLC100 liquid level sensor and Powercast wireless sensor development kit. The wireless system is divided into two parts, level measurement and data transmission part as well as data receiving and display part. First part included the capacitive liquid level sensor CLC100 and the wireless senor board. CLC100 sensor was used for liquid level measurement. Wireless sensor kit from Powercast Corporation included one wireless sensor board, which was used for signal transmission. A built-in PIC microcontroller was embedded in the transmission module, for the purpose of processing and data transmitting. Due to CLC100 sensor’s output voltage exceeding the sensor board’s input limitation, a voltage convertor was designed to connect the sensor and the wireless sensor board. The final results were voltages corresponding to the liquid level, and were processed by an independent PIC development board, and then sent to PC’s hyper terminal via serial-port by this PIC microcontroller. Experiments showed that this wireless sensor node prototype worked well.
基金supported by the Guangxi Natural Science Foundation,China(Grant Nos.2023GXNSFDA026040 and ZY23055018)National Natural Science Foundation of China(Grant Nos.62365003,62364006,and U23A20282)+2 种基金the Fonds de la Recherche Scientifique under the Postdoctoral Researcher Grant(Chargéde Recherches)Belgium to Xuehao HUthe Innovation Project of Guilin University of Electronic Technology Graduate Education,China(Grant No.2024YCXS202).
文摘The work describes a surface plasmon resonance(SPR)sensor that measures the liquid level and refractive index(RI)simultaneously.The sensor is fabricated by a polymer optical fiber(POF)with a side-polished spiral structure.The POF is wound around a plastic rod with the same pitch and polished into a series of separated side-polished areas to form the sensor probe.Afterwards,the polished surfaces are coated with a gold layer to construct the SPR sensor.The proposed sensor can provide multi-point liquid-level measurement besides RI sensing.The influences of structural parameters such as the bending radius,polishing depth,and pitch on the sensing performance are experimentally studied.The experimental results indicate that the RI could be determined by employing the SPR wavelength shift,and the RI sensitivity of 1862 nm/RIU within the 1.34–1.40 range is obtained.Moreover,the SPR peak’s depth variation can be utilized to monitor the liquid level,and the sensor can provide adjustable resolution and a measurement range for liquid level sensing.With its simple fabrication,low cost,and flexible sensing ability,this sensor probe is suitable for the usage in biochemical applications.
基金financially supported by the National Natural Science Foundation of China(No.52006041)the Guangdong Academy of Sciences(Nos.2021GDASYL-20210103101,2020GDASYL-20200101001,2022GDASZH-2022010109)the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030006)。
文摘The solid-liquid mixing is an important operation unit in the preparation of composites by stirring casting.High quality composite materials need good homogeneity and stable liquid level.In this work,the performances of the Rotor-Stator agitator for solid suspension in stirred tank were investigated through CFD modeling,including the homogeneity,power consumption and liquid level stability.The Eulerian-Eulerian(E-E)multiphase model and the RNG k-εturbulence model were adopted for modeling the multiphase flow and the turbulence effects,respectively.The effect of various important parameters such as stirring speed,particle size,solid loading and the use of baffles were examined.Adding a stator structure with array holes outside the rotor can optimize the flow pattern,thereby improving the mixing uniformity and liquid level stability.The homogeneity and liquid level stability attained by the Rotor-Stator agitator were better than those for the A200(an axial-flow agitator)and the Rushton(a radial-flow agitator).
基金funded by National Key R&D Program of China(No.2018YFB2002500)Zhejiang Province Key R&D programs(Nos.2021C05004 and 2020C03039)+2 种基金NSFC(Nos.61974037,61904042,and 61801158)Natural Science Foundation of Zhejiang(No.LY21F040006)Zhejiang University Education Foundation Global Partnership.
文摘Self-powered sensors are highly sought for wireless sensing applications in space exploration,industries,and environmental monitoring,etc.However,most current self-powered sensor technologies are based on the multiple energy conversion routine:energy collection,rectification,energy storage,and power management before it can be used for sensor systems,leading to exceptionally low energy utilization efficiency and very short periods of wireless sensing operation with majority of information lost.Here,we propose a triboelectric nanogenerator(TENG)based fully self-powered instantaneous and real-time wireless sensor system which does not contain electronic devices and microchips,but the passive components only.An innovative cylindrical capacitive-type liquid level sensor is also proposed and is then integrated into the wireless sensor system for monitoring liquid levels or identifying substance of the liquids.This sensor system can convert pulsed voltage output of the TENG into sinusoidal signal with a resonant frequency containing the sensing information and is transmitted to the receiver in distance in real-time.The maximum transmission distance of the sensor system could reach 1.5 m for a 10 cm diameter magnetic-core coil pair.The wireless sensor system exhibited excellent stability and excellent linearity with a sensitivity of 4.63 kHz/cm,and demonstrated its great application potential for the self-powered liquid level monitoring.
基金supported by the Joint Research Fund in Astronomy under cooperative agreement between the National Natural Science Foundation of China (NSFC) and Chinese Academy of Sciences (CAS) (Nos. U1831115, U2031132, U1931206, and U2031130)Natural Science Foundation of Heilongjiang Province (No. ZD2019H003)Fundamental Research Funds for the Central Universities to the Harbin Engineering University
文摘In this paper,a novel liquid level sensor with ultra-high sensitivity is proposed.The proposed sensor is configured by a sliceshaped composite long period fiber grating(SSC-LPFG).The SSC-LPFG is prepared by polishing two opposite sides of a composite multimode-single-mode-multimode fiber structure using a CO;laser.The method improves the sensitivity of the sensor to external environment.Based on the simulation calculation,a liquid level sensor with a length of 3 mm is designed.The experimental transmission spectrum agrees well with the simulation result.The experimental results show that the sensitivity reaches 7080 pm/mm in the liquid level range of 0-1400 μm in water.The temperature sensitivity is24.52 pm/℃ in the range of 20℃-90℃.Due to the ultra-high sensitivity,good linearity,and compact structure,the SSC-LPFG has potential application in the field of high-Drecision liquid level measurement.
基金Supported by National Science Foundation of China(11055003,11175117)Science and Technology Commission of Shanghai Municipality(11PJ1405300)Ministry of Science and Technology of China(2010CB833005)
文摘The two-phase xenon detector is at the frontier of dark matter direct search. This kind of detector uses liquid xenon as the sensitive target and is operated in two-phase （liquid/gas） mode, where the liquid level needs to be monitored and controlled in sub-millimeter precision. In this paper, we present a detailed design and study of two kinds of level meters for the PandaX dark matter detector. The long level meter is used to monitor the overall liquid level while short level meters are used to monitor the inclination of the detector. These level meters are cylindrical capacitors that are custom-made from two concentric metal tubes. Their capacitance values are read out by a universal transducer interface chip and are recorded by the PandaX slow control system. We present the developments that lead to level meters with long-term stability and sub-millimeter precision. Fluctuations （standard deviations） of less than 0.02 mm for the short level meters and less than 0.2 mm for the long level meter were achieved during a few days of test operation.
文摘A novel fiber optic liquid level sensor based on laser radar (ladar) is reported here. Using the perfect technique of ladar in which the phase of amplitude modulated light wave reflected from the liquid surface is compared with that of original modulation signal, the distance can be measured precisely. A special symmetric compensating coaxial optical system is proposed to eliminate many adverse effects. It realized the one-time electronic-free optical measurement on a simulated oil tank and achieves an accuracy of 0.3%, within a temperature range of -10 ℃～+40 ℃ over a measuring of 0～10 m.
基金Project supported by the Second Stage of Brain Korea 21 Projects
文摘Many kinds of high temperature superconductor （HTS） power machines such as HTS cable, HTS fault current limitcr and HTS magnet are cooled by liquid nitrogen. The level of liquid nitrogen should be monitored and controlled to ensure the thermal stability and the dielectric strength as well. To measure the level, capacitance method and differential pressure method are usually used. However, each method has installation difficulties and measurement errors for unsteady state operation with varying system pressure. A new liquid level meter using a 2G HTS conductor is described, which has similar structure with the liquid helium level meter with NbTi filament. The level meter is fabricated with a parallel connected heater, which helps the separation of the superconducting region and normal region, considering the critical temperature, large heat capacity of conductor and cooling characteristics. The level of liquid nitrogen can be obtained from the measured voltage signal along the 2G HTS conductor. Design, fabrication and test results of the new liquid nitrogen level meter are presented.
文摘Utilizing the technology of Ultrasonic wave,relevant test arithmetic and the PC to carry on monitoring,controlling and cen-tralized management of the liquid-level in the liquid container. It can prevent from keeping in touch with the examined liquid,not only has increased the continuous working time of the system greatly,simplifying maintenance of the sensor conveniently,can also realize overhauling in producing and boost the productivity and management level. The working principle,hardware structure of the instrument and the design method are presented,and the selection of sensor and MCU is discussed in detail in this paper. MCU are used to control the emission and receiving. Then the liquid-level are calculated,which makes the design more intelligent.
文摘Basic properties of a silica-based octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) extraction resin (CMPO/SiO2-P) was investigated.Adsorption behavior for some rare earth elements (RE) which are constituents of high level liquid waste (HLLW) and the long-term stability of the extraction resin in nitric acid solution were examined.The CMPO extraction resin was significantly stable in 3 mol·L?1 HNO3 solution at 50oC.Furthermore,the RE(III) were efficiently separated from non-adsorptive fission product (FP) elements such as Sr(II) in a column experiment using a highly nitric acid solution.The separation behaviors of the elements are considered to result from the difference in their adsorption and elution selectivity based on the complex formation with CMPO.There was no strong dependency of RE(III) separation efficiency on feed solution flow rate.Only from the perspectives of the acid-resistant behavior of CMPO extraction resin and the elution kinetics for the metal ions with the extraction resin,the CMPO extraction resin can be used in the modified MAREC process for HLLW partitioning.
基金National Natural Science Foundation of China(No.61261029)
文摘The radar echo signal of non-stationary and singular points usually contains false echoes,which affects the recognition and measurement of liquid level echo signal.In order to eliminate false echo interference and improve the recognition and measurement accuracy of the liquid level gauge,a method of echo recognition and correction based on adaptive least mean square(LMS)is proposed.The short-time amplitude function and short-time zero crossing rate function are combined to recognize the echo signal.The weight vector iteration and updating weight coefficients are obtained by LMS method.The echo signal is recognized and the false echo interference is suppressed.The experimental results show that the level echo signal can be accurately recognized by this method,and level measurement accuracy can reach0.47%F.S.Compared with other denoising methods,adaptive LMS can keep the signal singularity characteristics while suppressing the noise.Moreover,it has better robustness.
