Differential Pressure Transmitter Research Articles

SISTEM KONTROL LEVEL TRANSMITTER PADA TANGKI FA-920 DI PT. SINTAS KURAMA PERDANA

Instrumentation is a very important tool in a measurement system, one of which is measuring the height of the liquid surface, this tool must be able to function properly in accordance with the instrumentation needs in the factory. Instrumentation is one of the factors that determine production results, where instrumentation tools measure, control, detect, analyze, both manually and automatically. Electric Differential Pressure Transmitter is a sensor that is used to measure the level of the liquid level as a tool to be read to the controller to the final setting.

Comparison of wind pressure coefficients between wind tunnel experiments and full-scale measurements using operational data from an urban high-rise building

Simulations during the design phase are performed to predict and evaluate the effect of natural ventilation of large buildings. Although the wind pressure coefficient has a significant impact on the prediction accuracy, comparisons between experimental and measured wind pressure coefficients are rare, especially for high-rise buildings in urban areas and under low-velocity outdoor winds commonly used for natural ventilation. This study compared wind pressure coefficients obtained from wind tunnel experiments with measured values to determine their accuracy for a high-rise building with 190 differential pressure transmitters installed on the walls for building monitoring and control. The building is located in an urban area, with several nearby buildings of comparable height. Long-term measurements were available, allowing for a sufficient number of samples even if they were limited to low-velocity outdoor winds. We processed the differential pressure data during building operation to obtain the wind pressure coefficient and compare it with that obtained from wind tunnel experiments. The results showed that the measured wind pressure coefficient can be obtained by appropriately processing the differential pressure data to exclude factors other than wind pressure, and that the measured wind pressure coefficient generally agrees well with the experimental value obtained by wind tunnel experiments.

A new, automated method for the investigation of melting point depression under carbon dioxide pressure

The aim of this work was to develop a new, automated method for the detection of solid-liquid phase transitions in the presence of high-pressure carbon dioxide. This is allowed because of the dissolution of the medium in the sample during the solid-liquid-gas equilibrium measurement. The pressure of an empty reference cell and one containing a solid sample is compared by a differential pressure transmitter. A gradual heating program is conducted after their equal pressurization. The solid-liquid transition of the sample is marked by a sharp decrease in the pressure of the sample holder (compared to the reference cell). A processing algorithm for the recorded time – temperature – pressure-difference data was implemented, to determine the melting temperature range accurately and automatically. The apparatus was validated with racemic ibuprofen and benzoic acid, and provides a new, objective, and easy-to-automate alternative to determine the melting temperature in high-pressure carbon dioxide.

Experimental study of flow field and transition characteristics in rod bundle channel

Utilizing the particle image velocimetry (PIV) technique, this study investigates the fully developed flow field and turbulence statistics in a 5×5 rod bundle across 22 cases, with Reynolds numbers ranging from 310 to 12296.Time-averaged, statistical, and spectral analyses were performed on the full field and instantaneous velocity vectors obtained through PIV measurements to examine the velocity distribution, turbulence characteristics, and spectral features in different subchannels under various Reynolds numbers. In conjunction with a differential pressure transmitter, the flow properties and fluid transitions were also explored.The experimental results reveal that the relative velocity gradient in the rod bundle channel is more significant at lower Reynolds numbers. As the Reynolds number increases, the relative velocity distribution becomes more uniform. A comparison of experimental results from different planes indicates that the fluctuation velocity in the gap subchannel is greater than that in the inner subchannel, suggesting that tightly arranged rods can generate higher turbulence intensity. Furthermore, the transition observed through the friction factor in the rod bundle channel is less distinct than those in pipes, with the transition Reynolds number being approximately 900. A low Reynolds number effect is present in the rod bundle channel, where the dimensionless fluctuation velocity decreases as the Reynolds number increases. Upon reaching the transition Reynolds number, the area-averaged dimensionless fluctuation velocity abruptly rises. By examining the turbulence intensity variations at different positions within the rod bundle, it becomes evident that the transition Reynolds numbers vary across different subchannel positions. Ultimately, the experimental data can be employed to validate the applicability of turbulence models for different Reynolds numbers.

Effect of helical coil orientation on flow boiling process

The flow boiling process in helical coils is investigated experimentally to analyze the effects of the orientation of the helical coil on the local heat transfer distribution, pressure drop and critical heat flux. The literature review suggests that little information is available on the influence of the orientation on the heat transfer distribution, pressure drop and critical flux during flow boiling in helical coils. Experiments are performed on horizontal and vertical helical coils with R123 as the working medium. SS-304 tubes of 5.5 mm and 7.5 mm diameter with a coil diameter of 150 mm are chosen in this study. Non-intrusive thermal imaging technique is used to measure the wall temperature. The differential pressure transmitter is used to measure the pressure drop across the test section. The two-phase pressure drop is not affected significantly by the orientation of the helical coils. The wall temperature, heat transfer distribution and the critical heat flux are affected by the orientation of the helical coil. The local and average heat transfer coefficient is higher in vertical oriented helical coils than the horizontal oriented helical coils. The value of heat flux at the burnout is higher in vertical orientation compared to horizontal orientation in both the coils.

Experimental Investigation of Rod Pitch Effect on Void Fraction in 5 × 5 Rod‐bundle under Elevated Pressure Conditions

In the present study, void fraction distributions in 5 × 5 rod-bundle test sections were investigated. Two different rod-bundle test sections with different rod pitch lengths were constructed. Experiments were carried out using unheated rod-bundle test sections equipped with 10 mm rod diameter with rod-pitch lengths of 13 and 12 mm, respectively. The HUSTLE (Hitachi Utility Steam Test Leading Facility) facility supplied steam and water with an inlet mass flux (G) ranging from 75 to 500 kg/m2/s at 5.0 to 7.5 MPa system pressure. These inlet and boundary conditions simulate the prototypic BWR at natural circulation conditions. For the measurement of void fraction, the X-ray CT system was newly developed for the three-dimensional time-averaged void fraction measurement, and 3D void fraction distributions were successfully obtained for various pressure conditions. The volume-averaged void fraction was also measured using differential pressure transmitters. Based on the newly developed void fraction database, the assessment was carried out using state-of-the-art drift-flux correlations applicable for rod-bundle. Existing correlations tend to show good void fraction prediction at high mass flux conditions for both geometries, poorer performance was shown for the narrow rod test sections with low mass flux conditions. Furthermore, the effect of the rod-pitch lengths on void fraction distribution in rod-bundle flow field was assessed. It was observed that narrower rod bundle configuration tends to have higher void fraction at given mass flux. Narrowed pitch-length enhances wall-friction against two-phase flow, which likely suppress the central phase fraction peak tendency. This promotes lower distribution parameter values, results in increased area-averaged void fraction for narrower pitch test section. However, the present study revealed that no existing correlations could clearly capture the void fraction trend for the narrow rod test section.

A new two-fluid model for flow rate measurement of annular flow in horizontal pipe

Non-separation measurement is a research difficulty and hotspot in multiphase flow. In this paper, the multimodal ultrasonic sensors and differential pressure transmitter combined with two-fluid model are used to measure the wet gas flow rates under non-separation state. Firstly, a modeling measurement system is built. The liquid film thickness and pressure drop are obtained by using ultrasonic sensor and differential pressure transmitter. Based on the steady-state one-dimensional two-fluid model and the limitations of existing models, a new prediction model is proposed. Comparing the pressure drop data obtained by new two-fluid model with the experimental data, the errors are within ±30%. Then, wet gas flow rates measurement system is constructed. The liquid film thickness and gas velocity are measured by using multimodal ultrasonic sensors. Combined this new two-fluid model, the wet gas flow rates are obtained. The measurement errors of gas and liquid flow rate are within ±10% and ±15%.

Identification and Control of Non-Linear System Using Model Predictive controller

The modeling of level and temperature process is the most common problems in the process industry. In this paper system identification is performed for a hybrid tank system. Hybrid tank is an example for highly non-linear system. This system has two inputs heater current and flow and the outputs are level and temperature. The Main aim of this paper is to maintain level and temperature at a desired value. Input flow is measured using turbine flow meter. The output temperature is measured using RTD. The level is measured using differential pressure transmitter (DPT). The simulation is performed in MATLAB environment using system identification algorithm. Model Predictive controller is implemented for this identified model.

A Differential Pressure Technique for Void Fraction Measurement in Gas-Liquid Flow

Two-phase Gas-liquid flows have many industrial uses, such as hydrocarbon transportation and energy production. The knowledge and an accurate determination of the gas phase's proportion rate in the two-phase mixture known as the gas void fraction is necessary for optimal and secure sizing of the installations where this kind of flow takes place. This paper focuses on the possibility of using a cost-effective differential pressure transmitter to measure the void fraction parameter. It is obtained using a mathematical model derived from the energy balance equation and the measured pressure drop from the vertical upward gas-liquid flow. Results on flow void fraction obtained through the use of the conductance probe method, are used to validate those derived from the pressure drop that is evaluated by employing the differential pressure transmitter. The measurement accuracy of the void fraction measured using the pressure drop technique, is found to be principally affected by the flow pattern. Moreover, the slip ratio between the phases was the primary factor influencing the void fraction measurement by the differential pressure technique.

IMPLEMENTATION OF LEBESGUE SAMPLING METHOD AND DIGITAL SENSORS FOR CONTROLLING THE LEVEL VARIABLE IN A CONTINUOUS SYSTEM

This study aims to show that the continuous control from a level system can be efficiently measured and controlled using capacitive digital binary sensors, which in this case, replace the measurement signal from an analog differential pressure transmitter in a level control system. The binary sensors low cost and the digital output they process allow the reproduction of a correct signal and the estimation of a variable for controlling the water level inside the process tank through a proportional pneumatic level control valve, which receives the control signal from the Lebesgue sampling estimation algorithm applied herein for processing digital measurements. In this particular case, the Lebesgue algorithm is applied to reproduce the estimation of values obtained from the continuous signal in the real level process for the measurement and control. Also, are compared both, simulated and real outputs obtained using the Lebesgue algorithm and digital sensors, which were applied to a state observer controller that relates digital signals for controlling the real level system output. The application of the Lebesgue algorithm in the real level process concludes that the analog level signal can be efficiently reproduced using this method. In addition, the controller enables the system to smoothly conduct digital output processing using digital sensors to control the system output correctly, validating that not only analog sensors should be applied for controlling the output of proportional actuators, because it is shown that digital binary signals can be used for controlling and emulating continuous signals, which were processed and applied to the pneumatic valve. Keywords: Lebesgue sampling, estimation, binary sensor, observer controller, finite state machine, continuous system, control, LTI systems, identification, state variable, estimated output, proportional actuator

Experimental Study of Pressure Loss in a 5 × 5–Rod Bundle With the Mixing Vane Spacer Grid

Axial and lateral pressure loss in a 5 × 5 rod–bundle with a split-type mixing vane spacer grid was experimentally measured using differential pressure transmitters at different sub-channel Reynolds numbers (Re) and orienting angles. The geometrical parameters of the 5 × 5–rod bundle are as follows: they have the same diameter (D = 9.5 mm) and pitch (p = 12.6 mm) as those of real fuel rods of a typical pressurized water reactor (PWR), with a sub-channel hydraulic diameter (Dh) of 11.78 mm. The characteristics and resistance models of pressure loss are discussed. The main axial pressure loss is caused by the spacer grid, and the spacer grid generates additional wall friction pressure loss downstream of the spacer grid. The lateral pressure loss shows strong correlations with orienting angles and distance from the spacer grid. The lateral pressure loss shows a sudden burst in the mixing vanes region and a slight augmentation at z = 3Dh. After 3Dh, the lateral pressure loss decays in an exponential way with distance from the spacer grid, and it becomes constant quickly at z = 20Dh.

Effect of SDS surfactant on gas-liquid flow and slug characteristics in slightly upward pipeline

A new pigging approach with SDS (Sodium dodecyl sulfate) surfactant was proposed for foam drainage in the gathering pipelines with wet gas production, especially for the pipeline section with a great pigging risk. For this purpose, the loop of gas-liquid two-phase flow with a 3 ° slightly upward pipeline was designed. The flow pattern characteristics of gas-liquid two-phase flow were collected by a high-speed camera, and the flow patterns with typical morphological structure were classified. Ultrasonic Doppler velocimeter and ultrasonic transducer were used to measure the velocity signal of the liquid phase near the pipe, and the slug frequency was calculated accurately according to the change of velocity profile data. The slug length was measured by the signal collected by pressure and differential pressure transmitter. The results show that with the addition of SDS surfactant, the flow pattern of gas-liquid two-phase flow is obviously improved, and the working condition of slug flow is suppressed. Besides, in the specific slug flow condition, the slug frequency decreases significantly and the slug length increases. It indicates that the addition of SDS surfactant is favorable to liquid discharge, and provide a reference value for the application of SDS surfactant in foam drainage in wet-gas gathering pipelines.

A new automatic measurement system for high-speed railway substructure settlement based on hydrostatic pressure difference levelling

Exact settlement measurement of substructures plays an important role in their status detection throughout all-life-cycle of high-speed railway. A Hydrostatic Pressure Difference Levelling system (HPDL) is developed based on the mechanism that pressures of any two points at different elevations in incompressible static liquid are different. The approach accounts for a hyperbolic variation in the density of the pressure transmission liquid with temperature, variation in the earth’s gravitational field and the elevation at the measurement point. High accuracy capacitive differential pressure transmitters are adopted owing to their high sensitivity, temperature-insensitive, low energy consumption, and sensing stability. The HPDL results are verified with settlement values measured by the precise level. It was demonstrated that the HPDL results correlate well with the precise level and can be considered as an effective method to measure the settlement of high-speed railway substructures.

Pressure Drop dan Pola Aliran Dua Fase (Air-Udara) Melewati Pipa Groove Vertikal

This research was conducted to observe the effect of adding grooves in the two-phase flow of water-air in the same direction through a vertical pipe to changes in pressure and fluid flow patterns. Test section in the form of pipes with grooves made of acrylic material with a length of 100 cm and an internal diameter of 2.54 cm. The geometric shape of the acrylic pipe is modified by giving a groove in the direction of the pipe along the test section. Grooves used amounted to 4 and 16 and pipes without grooves used as a comparison. Tests are carried out by flowing water and air that has been mixed through the inlet side upward. The ratio of air velocity to water velocity (VG / VL ) is 0.24-1.13. The method used in this study is experimental. Retrieval of pressure drops data is done by using a differential pressure transmitter. Visual observations are also made using a DSLR camera equipped with a flash and video observations using a smartphone with slow-motion mode. The results showed changes in flow patterns and pressure drop values. Slugs in pipes with grooves disappear faster and pressure drops are lower than pipes without grooves.

Monitoring and Control of Cooler Tank Level Measurement In Gas Cleaning Plant (GCP)

The Cooler Tank Level plays a major role in Gas Cleaning Plants (GCP) and it is a very important parameter to be measured and controlled. If the tank level is not maintained in nominal range, the dust particles will accumulate on the Cooler Tank and affect the process. The production of copper metal at Vedanta, Thoothukudi include Blending of various grades of copper concentrates, Smelting and Refining. Sulphur dioxide is generated from during the smelting of copper and is converted to Sulphuric acid as a byproduct. This process involves three steps such as cleaning of sulphur dioxide gas from Furnace, Catalytic conversion of S02 to SO3 and amalgamation of SO3 with sulphuric acid. The conversion process is exothermic, reversible and adiabatic reaction and hence if the temperature increases it destroys the formation of sulphur trioxide. Hence in order to achieve high conversion efficiency, the converter gases need to be cooled. The SO2 gas from smelter contains metallic dust, fume, acid mist, water vapour and other impurities like halides which will contaminate the product. Therefore the gases are to be cooled and cleaned in Gas Cleaning Plant (GCP). Cooler tank used to remove water vapour from the gas and dust settle at the bottom of cooler. Cooler tank level needs to be maintained in order to avoid overflow of water into scrubber which will block the inlet gas. The level of cooler tank is to be continuously monitored and controlled to achieve the optimum results. The limitations of using Differential Pressure Transmitter for level measurement are overcome by ultrasonic based level sensor and automated using Distributed Control System and Human Machine Interface (HMI).

Differential Pressure Transmitter With Unified Electronics Unit

Differential pressure is an important technological parameter. To date, the lion's share of research in this area has focused on the development and improvement of differential pressure transmitters. This article is devoted to developing a differential pressure transmitter with unified electronics unit. To achieve this objective, modern methods and technologies were used in the development of the electronics unit of the pressure transmitter. The Programmable System-on-Chip (PSoC) technology was used to develop the electronics unit. Due to the use of PSoC technology, it was possible to increase the noise immunity of the developed differential pressure transmitter, as well as provide an unparalleled combination of flexibility, integration analog and digital functionality. The operational principle of the developed differential pressure transmitter is based on the dependence of the elastic deformation of the sensitive element of the transmitter on the pressure. A strain gauge and a differential capacitive sensor were considered as sensitive elements of the proposed differential pressure transmitter.

Effects of the Microbubble Generation Mode on Hydrodynamic Parameters in Gas–Liquid Bubble Columns

The hydrodynamics parameters of microbubbles in a bubble column were studied in an air–water system with a range of superficial gas velocity from 0.013 to 0.100 m/s using a differential pressure transmitter, double probe optical fiber probe, and electrical resistance tomography (ERT) technique. Two kinds of microbubble generators (foam gun, sintered plate) were used to generate microbubbles in the bubble column with a diameter of 90 mm, and to compare the effects of different foaming methods on the hydrodynamics parameters in the bubble column. The hydrodynamic behavior of the homogeneous regime and the transition regime was also studied. The results show that, by changing the microbubble-generating device, the hydrodynamic parameters in the column are changed, and both microbubble-generating devices can obtain a higher gas holdup and a narrower chord length distribution. When the foam gun is used as the gas distributor, a higher gas holdup and a narrower average bubble chord length can be obtained than when the sintered plate is used as the gas distributor. In addition, under different operating conditions, the relative frequency distribution of the chord length at different radial positions is mainly concentrated in the interval of 0–5 mm, and it is the highest in the center of the column.

A Comparative Study of Pressure Losses and Hole Cleaning Efficiency of Water and Polymer solutions in Horizontal Wells

The main objective of this study is to experimentally investigate the effect of the CMC polymeric drag reducer on the pressure drop occurred along the annulus of the wellbore in drilling operation and investigate the optimum polymer concentration that give the minimum pressure drop. A flow loop was designed for this purpose consist from 14 m long with transparent test section and differential pressure transmitter that allows to sense and measure the pressure losses along the test section. The results from the experimental work show that increasing in polymer concentration help to reduce the pressure drop in annulus and the optimum polymer concentration with the maximum drag reducing is 0.8 kg/m3. Also increasing in flow rate and corresponding fluid velocity in the gap of the annulus helped to reduce the pressure losses due to fluid flow.

Experimental study of cross flow and lateral pressure drop in a 5 × 5 rod bundle with mixing vane spacer grid

Cross flow and lateral pressure drop downstream a split-type mixing vane spacer grid in a 5 × 5 rod bundle were experimentally measured by particle image velocimetry (PIV) and differential pressure transmitter at the sub-channel Reynolds number (Re) of 13200. The geometrical parameters of the 5 × 5 rod bundle is as the same diameter (D = 9.5 mm) and pitch (P = 12.6 mm) as the real fuel rods of a typical pressurized water reactor (PWR), with sub-channel hydraulic diameter (Dh) 11.78 mm. With the aid of matched index of refraction (MIR) technique of transparent fluorinated ethylene propylene (FEP) tubes and water, the PIV measurements of cross flow covering all sixteen inner-sub-channels were conducted for cross sections at 1Dh, 4Dh, 8Dh and 16Dh downstream the spacer grid. With detailed error and uncertainty analysis, the uncertainty of the turbulent statistics is mainly determined by the out of plane error and sampling number error. The maximum standard uncertainty of statistical quantities normalized by the bulk velocity is less than 1%. The characteristics of cross flow were mainly determined by the mixing vanes of spacer grid in rod bundle. The mixing vanes generate strong cross flow and drastic turbulence flow downstream the spacer grid, enhancing the cross flow mixing and turbulent mixing between sub-channels. The lateral pressure drop was measured at 1Dh, 2Dh, 3Dh, 4Dh, 5Dh, 6Dh, 8Dh, 10Dh, 12Dh, 14Dh, 16Dh, 18Dh and 20Dh. The relative uncertainty level of lateral pressure drop is between 0.7% and 7.0%. Downstream the spacer grid, the lateral pressure drop increases from 1Dh to 2Dh. After 3Dh, the lateral pressure drop decays in exponential way with distance from spacer grid. After 16Dh, the lateral pressure drop almost keeps constant.

METHOD FOR DETECTING AGING RELATED FAILURES OF PROCESS SENSORS VIA NOISE SIGNAL MEASUREMENT

In this article we examine the methods for detecting and predicting aging related process sensor failures by analyzing the noise of the sensor output signal. The study uses data from non-differential and differential pressure transmitters used in the pressure and water level measurements of the reactor pressure vessels of units 1 and 2 of the Olkiluoto nuclear power plant in Finland. The article contains a review of the current methods for detection of sensor failures. Additionally, we present a new method for detecting changes in the sensor output signal. The method creates fingerprints of the power spectra of the sensors by using Principal Component Analysis (PCA). The changes in these fingerprints together with the measurements of the redundant sensors can be used to detect indications of some of the impending sensor failures. In the experimental study we are able to produce stable fingerprints for both the non-differential and differential pressure transmitters. Also, a potential failure in one of the differential pressure transmitters in Olkiluoto unit 2 is detected by inspecting the fingerprints and analyzing the spectral changes of the transmitter output signal.