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Search results for: MAGNETOELECTRIC VOLTAGE COEFFICIENT
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SEM image and EDS map of SrTi0.65Fe0.35O3-d powder aglomerate
Open Research DataThis dataset contains image of the SrTi0.65Fe0.35O3-d powder aglomerate with EDS map analysis results. Images were obtained using a PhenomXL (Thermo Fisher Scientific, the Netherlands) scanning electron microscope (SEM) with an accelerating voltage of 10 kV in a high vacuum mode. The chemical compositions of the investigated powder were determined...
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SEM image and EDS map of SrTi0.30Fe0.70O3-d powder aglomerate
Open Research DataThis dataset contains image of the SrTi0.30Fe0.70O3-d powder aglomerate with EDS map analysis results. Images were obtained using a PhenomXL (Thermo Fisher Scientific, the Netherlands) scanning electron microscope (SEM) with an accelerating voltage of 10 kV in a high vacuum mode. The chemical compositions of the investigated powder were determined...
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Programmable Input Mode Instrumentation Amplifier Using Multiple Output Current Conveyors
PublicationIn this paper a programmable input mode instrumentation amplifier (IA) utilising second generation, multiple output current conveyors and transmission gates is presented. Its main advantage is the ability to choose a voltage or current mode of inputs by setting the voltage of two configuration nodes. The presented IA is prepared as an integrated circuit block to be used alone or as a sub-block in a microcontroller or in a field...
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Electroelastic biaxial compression of nanoplates considering piezoelectric effects
PublicationIn the present theoretical work, it is assumed that a piezoelectric nanoplate is connected to the voltage meter which voltages have resulted from deformation of the plate due to in-plane compressive forces whether they are critical buckling loads or arbitrary forces. In order to derive governing equations, a simplified four-variable shear deformation plate theory has been employed using Hamilton’s principle and Von-Kármán...
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Induction Generator with Direct Control and a Limited Number of Measurements on the Side of the Converter Connected to the Power Grid
PublicationThe article presents an induction generator connected to the power grid using the AC/DC/AC converter and LCL coupling filter. Three-level inverters were used in the converter, both from the generator side and the power grid side. The algorithm realizing Pulse Width Modulation (PWM) in inverters has been simplified to the maximum. Control of the induction generator was based on the Direct Field-Oriented Control (DFOC) method. At...
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Electro-mechanical shear buckling of piezoelectric nanoplate using modified couple stress theory based on simplified first order shear deformation theory
PublicationThis paper studies the electro-mechanical shear buckling analysis of piezoelectric nanoplate using modified couple stress theory with various boundary conditions.In order to be taken electric effects into account, an external electric voltage is applied on the piezoelectric nanoplate. The simplified first order shear deformation theory (S-FSDT) has been employed and the governing differential equations have been obtained using...
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Properties of chitosan/CuNPs coatings electrophoretically deposited on TiO2 nanotubular oxide layer of Ti13Zr13Nb alloy
PublicationCoatings based on chitosan/CuNPs (chit/CuNPs) were obtained by a one-step electrophoretic deposition (EPD) on nanotubular oxide layer of Ti13Zr13Nb alloy. The deposition was carried out for 1 min applying voltages of 10 and 20 V with and without the addition of dispersing agent (Polysorbate 20) to the suspension. The coatings obtained for the lower voltage were more uniform than for the higher voltage. By adding a dispersing agent,...
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Sensorless predictive control of three-phase parallel active filter
PublicationThe paper presents the control system of parallel active power filter (APF) with predictive reference current calculation and model based predictive current control. The novel estimator and predictor of grid emf is proposed for AC voltage sensorless operation of APF, regardless of distortion of this voltage. Proposed control system provides control of APF current with high precision and dynamics limited only by filter circuit parameters....
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Dual drive control under SVPWM, experimental results
Open Research DataThe dataset contains the experimental results of the project: A universal algorithm of space vector pulse width modulation for three-level three and multi-phase NPC inverters with DC-link voltage balancing. The analysis includes the behaviour of the drive system, examining the dynamic system response to speed and angle changes, and encompassing data...
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SEM image and line EDS of SrTi0.50Fe0.50O3-d porous electrode sintered at 800 °C
Open Research DataThis dataset contains image of the SrTi0.50Fe0.50O3-d porous electrode sintered at 800 °C with line EDS analysis results. Images were obtained using a PhenomXL (Thermo Fisher Scientific, the Netherlands) scanning electron microscope (SEM) with an accelerating voltage of 20 kV in a high vacuum mode. The chemical compositions of the investigated powder...
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EFFECT OF NANOFLUID CONCENTRATION ON TWO-PHASE THERMOSYPHON HEAT EXCHANGER PERFORMANCE
PublicationAn approach – relaying on application of nanofluid as a working fluid, to improve performance of the two-phase thermosyphon heat exchanger (TPTHEx) has been proposed. The prototype heat exchanger consists of two horizontal cylindrical vessels connected by two risers and a downcomer. Tube bundles placed in the lower and upper cylinders work as an evaporator and a condenser, respectively. Distilled water and nanofluid water-Al2O3...
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Economics of credit scoring management
PublicationCredit scoring models constitute an inevitable element of modern risk and profitability management in retail financial lending institutions. Quality,or separation power of a credit scoring model is usually assessed with the Gini coefficient. Generally, the higher Gini coefficient the better, as in this way a bank can increase number of good customers and/or reject more bad applicants. In...
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Calibration of NTC 10k thermistors in temperature of 0 C
Open Research DataThe presented data set is part of the research aimed at determining the actual characteristics of each thermistor in a package of twenty NTC10k type sensors.
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Calibration of NTC 10k thermistors in temperature of 100 C
Open Research DataThe presented data set is part of the research aimed at determining the actual characteristics of each thermistor in a package of twenty NTC10k type sensors.
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Calibration of NTC 10k thermistors in temperature of 50 C
Open Research DataThe presented data set is part of the research aimed at determining the actual characteristics of each thermistor in a package of twenty NTC10k type sensors.
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A Single-Carrier-Based Pulse-Width Modulation Template for Cascaded H-Bridge Multilevel Inverters
PublicationMultiplicity of the triangular carrier signals is a criterion for the extension of sinusoidal pulsewidth modulation, SPWM, to a number of output voltage levels per phase-leg in cascaded H-bridge (CHB) multilevel inverter (MLI). Considering medium and high voltage applications where appreciable number of output voltage levels from CHB MLI is needed, commensurate high number of carrier signals in either classical level- or phase-shifted...
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Formowanie wektorów napięcia wyjściowego w pięciofazowych falownikach napięcia
PublicationW falownikach pięciofazowych, załączenie wektorów aktywnych powoduje jednoczesne formowane dwóch, zależnych od siebie wektorów napięcia wyjściowego. Sterowanie pięciofazowymi silnikami indukcyjnymi wymaga, aby wektory te miały ściśle określone długości i położenia. Niezależne formowanie dwóch wektorów napięcia o parametrach określonych w układzie sterowania silnikiem wymaga zastosowania odpowiedniej strategii Modulacji Szerokości...
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Simplified saturation modelling in three-leg power transformer for the system stability analisys
PublicationThe paper presents a simplified method for modelling non-linearity of the magnetic circuit of the power transformer. The saturation effect is implemented by describing the self and mutual inductances as a function of the magnetic flux. The most important element of this function is the saturation coefficient which is calculated based on transient state during the unloaded transformer switch on. The transformer model is described...
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Optimal Rotating Receiver Angles Estimation for Multicoil Dynamic Wireless Power Transfer
PublicationThis study proposed an approach to dynamic wireless charging that uses a rotating receiver coil. Our simulation study focused on the verification of a novel way of increasing the coupling coefficient and power transfer stability by following the flux of the transmitting coils. To obtain the highest possible coupling by means of the FEM analysis, we studied the optimization of the trajectory of the angular velocity of the rotating...
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Investigation of RTS Noise in Reverse Polarized Silicon Carbide Schottky Diodes
PublicationOne of the method of electronic device quality and reliability evaluation is observation of its inherent noise. The RTS phenomena usually indicates the presence of large defects in the structure of the material of the device, therefore it can be treated as an indicator of technology quality. In the paper authors present results of RTS investigations in reverse polarized Silicon Carbide Schottky diodes. Devices being studied are...
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Virtual Space Vector Pulse Width Modulation Algorithm for Three-Level NPC Converters Based on the Final Element Shape Functions
PublicationThe paper puts forth a novel idea for the computation of Nearest Three Virtual Space Vector Pulse Width Modulation for the three level NPC converters. The computations are based on the concept of final element shape function widely used in the domain of finite element analysis. The proposed approach significantly frees the computations from the use of trigonometric functions, which simplifies the computations and permits easier...
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Dielectric Barrier Discharge Systems with HV Generators and Discharge Chambers for Surface Treatment and Decontamination of Organic Products
PublicationThe article presents applications of systems with power electronic converters, high voltage transformers, and discharge chambers used for nonthermal, dielectric barrier discharge plasma treatment of a plastic surface and decontamination of organic loose products. In these installations, the inductance of the high voltage transformers and the capacitances of the electrode sets form resonant circuits that are excited by inverters....
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An Extended Control of the Input Angle for Matrix Converters Connected with the Non-Unity Power Factor Loads.
PublicationThis paper proposes a novel PWM modulation algorithm for Multiphase Conventional Matrix Converters (MCMC), with 3 inputs and k outputs, using the transfer function of the load angle. The proposed approach extends the range of power angle control at the input during the operation with a maximum voltage transfer ratio. The proposed concept is based on the Direct Analytic Voltage PWM (DAV--PWM) modulation with an elliptical trajectory...
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Low Current Transformer Utilizing Co-Based Amorphous Alloys
PublicationMetal oxide surge arresters have been widely used for protection of power system networks against overvoltages due to atmospheric discharges or malfunction of devices connected to the network. During its operation a surge arrester structure is degradated, what can be observed as an increase of a surge arrester leakage current. Paper presents an implementation of a new, high-permeability, Co64Fe4Ni1Si15B14 amorphous alloy as a current...
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Low current transformer utilizing Co-based amorphous alloys
PublicationMetal oxide surge arresters have been widely used for protection of power system networks against overvoltages due to atmospheric discharges or malfunction of devices connected to the network. During its operation a surge arrester structure is degradated, what can be observed as an increase of a surge arrester leakage current. Paper presents an implementation of a new, high-permeability, Co64Fe4Ni1Si15B14 amorphous alloy as a current...
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Przekształtnik prądu jako sterownik w układach napędowych z silnikami indukcyjnymi
PublicationThe circuits used for power conversion applied in drives with electric machines are classified into two groups: voltage source inverters (VSI) and current source inverters (CSI). Application of the current source inverter results in better properties of drive than application of voltage source inverter because there is no output filter. The development of power electronics and especially the IGBTs, in which on/off-times are very...
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Incomplete Cross-Bonding in the MV Line. Experience from the Operation of MV Single Cable Lines
PublicationCable lines are one of the basic components of power systems. Medium and high voltage cables mainly comprise a metallic sheath, which is concentric to the main core conductor. There are several operating schemes of such cable lines, which differ in the place of earthing of sheaths and the possible use of the sheaths and/or conductors crossing. The sheaths cross-bonding is typically done in two places of one cable line section,...
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Study of Metrological Properties of Voltammetric Electrodes in the Time Domain
PublicationMetrological properties of voltammetric electrodes, in the situation where on their surface an electrochemical reaction of oxidizing/reduction takes place, were analyzed in this chapter. The properties of electrodes on which a reaction controlled by ion transport process takes place were taken into consideration. Also, it was analyzed how the electrode’s shape and the voltage polarizing the electrode influence this electrode’s...
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Formowanie napięć wyjściowych trójfazowego przekształtnika sieciowego
PublicationW artykule przedstawiono kompensację dwu zasadniczych zjawisk powodujących zniekształcenia prądów fazowych przekształtnika sieciowego. Pierwszym z nich są zniekształcenia napięcia sieci. W celu ich eliminacji zaproponowano uśrednianie za okres podstawowej harmonicznej uchybu regulatora napięcia obwodu pośredniczącego oraz predykcję napięcia sieci. Drugim natomiast są zniekształcenia napięć wyjściowych przekształtnika sieciowego....
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Numerical study on pounding between two adjacent buildings under earthquake excitation
PublicationSeismic excitation, which results in large horizontal relative displacements, may cause collisions between two adjacent structures due to insufficient separation distance between them. Such collisions, known as earthquake-induced structural pounding, may induce severe damages. In this paper, the case of pounding between two adjacent buildings is studied by the application of single degree-of-freedom structural models. Impact is...
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Applicability of arrays of microjets heat transfer correlations to design compact heat exchangers
PublicationThe article presents experimental studies on a compact heat exchanger with heat transfer intensification by means of impinging microjets. The pursuit to provide high performance of heat exchangers is a response to the demand both in economics and in the universal tendency to miniaturization of industrial equipment. This paper presents the design and tests of a prototype, microjet heat exchanger. The modular design of the heat exchanger...
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A simplified energy dissipation based model of heat transfer for subcooled flow boiling
PublicationIn the paper a model is presented based on energetic considerations for subcooled flow boiling heat transfer. The model is the extension of authors own model developed earlier for saturated flow boiling and condensation. In the former version of the model we used the heat transfer coefficient for the liquid single-phase as a reference level, due to the lack of the appropriate model for heat transfer coefficient for the subcooled...
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Instantaneous power signal measurements for bearing diagnostics
Open Research DataBearing diagnostics can be carried out based on the method, which relies on the measurement and analysis of the variability of the signal instantaneous power, defined as the product of instantaneous current and voltage power supplied to the engines. Bearing damage causes the appearance of deformations, which are in the form of additional harmonic components...
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Fe3–xInSnxO6 (x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering
PublicationThree new double corundum derivative compounds, Fe3−xInSnxO6 (x = 0. 0.25, or 0.5), were synthesized at high pressure and temperature (6 GPa and 1400− 1450 °C). All of the compounds order antiferromagnetically well above room temperature (TN = 608, 532, and 432 K for x = 0, 0.25, and 0.5, respectively). The x = 0 phase crystallizes as centrosymmetric R3̅c, but the inclusion of closed-shell d10 Sn4+ induces x = 0.25 and 0.5 to crystallize...
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Uncertainty estimation of loop impedance measurement determined by the vector method
PublicationThis article presents a detailed analysis of uncertainty estimation of loop impedance measurement determined by the vector method. The analysis includes the following estimates: resistance variance, voltage variance and time measurement variance. This paper presents a methodology for estimating the combined standard uncertainty of loop impedance by the vector method. The vector method allows to determine loop impedance based on...
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Measurement methods for assessing insulation condition of underground pipelines
PublicationThe paper discusses the most frequently applied measurement methods for assessing the quality of external insulation along pipelines and detecting defect locations in the protective coating. The quality of coating along a given pipeline section under investigation is assessed by determining unitary resistance of the coating, which is calculated on the basis of measurement results obtained along a pipeline subjected to cathodic...
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A robust 18-pulse diode rectifier with coupled reactors
PublicationThe article presents the principle of operation and selected results of simulation and laboratory tests of the 18-pulse rectifier system with coupled reactors and small series active power filter. The presented system makes it possible to reduce, especially in distribution supply networks, undesired higher current harmonics. The 18-pulse nature of operation of the rectifier is reached using a set of coupled three-phase network...
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A method of earth fault loop impedance measurement without unwanted tripping of RCDs
PublicationIn low-voltage networks, earth fault loop impedance (EFLI) measurement is the basis for assessing the effectiveness of automatic disconnection of supply. Such a measurement is performed during initial and periodical verification, especially in a TN low-voltage network. Nowadays, due to widespread application of residual current devices (RCDs), such test is difficult in many circuits because RCDs operate during the test. In this...
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Ancillary services to grids provided with distributed generation
PublicationThe paper introduces system for utilization of the customer-side generated energy. Additionally system can secure some ancillary services to grids. Those services include: current active filtering, load voltage stabilization and in case of grid voltage faults - uninterruptible load supplying (possible with energy storage device). Presented experimental results confirm flexibility of this arrangement in processes of power delivery...
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High Performance Control of AC Drives with Matlab/ Simulink
PublicationExplore this indispensable update to a popular graduate text on electric drive techniques and the latest converters used in industry. The Second Edition of High Performance Control of AC Drives with Matlab®/Simulink delivers an updated and thorough overview of topics central to the understanding of AC motor drive systems. The book includes new material on medium voltage drives, covering state-of-the-art technologies and challenges...
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Application of infrared thermoography to non-contact testing of varistors
PublicationTesting of varistors using thermography was carried out in order to assess their protective properties against possible overvoltage phenomena in the form of high-level voltage surges. An advantage of the thermography technique is non-contact temperature measurement. It was proposed to assess the properties of varistors workingin electronic devices as protective elements, on the basis of estimating temperature increments on varist...
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Sensorless Fault Detection of Induction Motor with Inverter Output Filter
PublicationThe paper presents the problem of monitoring and fault detection of a sensorless voltage inverter fed squirrel cage induction motor with LC filter. The detection is based on load torque estimation of the investigated torque transmission system. The load torque is calculated besides the computation of other variables that are mandatory for sensorless drive operation such as rotor flux and speed. The implemented LC filter smooths...
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Current Source Inverter Fed Drive
PublicationThis book covers three-phase and multiphase (more than three-phase) motor drives including their control and practical problems faced in the field (e.g., adding LC filters in the output of a feeding converter), are considered. The new edition contains links to Matlab®/Simulink models and PowerPoint slides ideal for teaching and understanding the material contained within the book. Readers will also benefit from the inclusion of: A...
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Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator
PublicationDue to ongoing research work, a prototype test rig for testing high-speed motors/generators has been developed. Its design is quite unique as the two high- speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate...
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SEM image and EDS map of SrTi0.50Fe0.50O3-d porous electrode sintered at 800 °C
Open Research DataThis dataset contains image of the SrTi0.50Fe0.50O3-d porous electrode sintered at 800 °C with EDS map analysis results. This study were performed for better understanding the chemical composition of flat like structures that occurs in electrode. Images were obtained using a PhenomXL (Thermo Fisher Scientific, the Netherlands) scanning electron microscope...
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Subcritical bifurcation of free elastic shell of biological cluster
PublicationIn this paper we will investigate symmetry-breaking bifurcation of equilibrium forms of biological cluster. A biological cluster is a two-dimensional analogue of a gas balloon. The cluster boundary is connected with its kernel by elastic links. The inside part is filled with compressed gas or fluid. Equilibrium forms of biological cluster can be found as solutions of a certain second order ordinary functional-differential equation...
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Electromagnetic-based derivation of fractional-order circuit theory
PublicationIn this paper, foundations of the fractional-order circuit theory are revisited. Although many papers have been devoted to fractional-order modelling of electrical circuits, there are relatively few foundations for such an approach. Therefore, we derive fractional-order lumped-element equations for capacitors, inductors and resistors, as well as Kirchhoff’s voltage and current laws using quasi-static approximations of fractional-order...
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Regulacja napięcia w sieci nN z rozproszonymi źródłami energii
PublicationPodłączanie rozproszonych źródeł energii do sieci energetycznych niskiego napięcia powoduje powstawanie problemów zmienności i niesymetrii napięcia, zwłaszcza w przypadku dużych odległości od transformatora zasilającego. W skrajnych przypadkach zachodzi konieczność redukcji mocy generowanej przez źródło podczas oddawaniu energii do sieci. Rozwiązaniem tego problemu jest zastosowanie energoelektronicznego regulatora napięcia składającego...
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Heat transfer in plate heat exchanger channels: experimental validation of selected correlation equations
PublicationThis study is focused on experimental investigation of selected type of brazed plate heat exchanger. The Wilson approach was applied in order to estimate heat transfer coefficients for the PHEx passages. The main aim of the paper was to experimentally check ability of several correlations published in the literature to predict heat transfer coefficients by comparison experimentally obtained data with appropriate predictions. The...
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Heat transfer in plate heat exchanger channels: experimental validation of selected correlation equations
PublicationThis study is focused on experimental investigation of selected type of brazed plate heat exchanger. The Wilson approach was applied in order to estimate heat transfer coefficients for the PHEx passages. The main aim of the paper was to experimentally check ability of several correlations published in the literature to predict heat transfer coefficients by comparison experimentally obtained data with appropriate predictions. The...