K-type Thermocouples Research Articles

Experimental investigation on the convection heat transfer enhancement for heated cylinder using pulsated flow

The paper presents experimental results regarding heat transfer behavior of a cylinder in cross pulsating flow and focuses on heat transfer characteristics enhancement obtained using a novel and peculiar type of pulsation technique able to generate variable pulsate signals with different frequencies. The pulsating flow tunnel features a square cross section of 200 mm × 200 mm and 1600 mm length, while the testing apparatus utilizes a station of normally closed (NC) solenoids and a vacuumed plenum chamber which can generate a time dependent flow inside the tunnel. Effects of pulsating frequency in the range 1–12 Hz and Reynolds number in the range 1.02–2.04*104 on convective heat transfer for both a horizontal and vertical heated cylinder are carried out. A cylindrical cartridge heater is embedded into the cylinder with two insulated ends to generate a constant heat flux of 33 W in all the experimental runs. The surface temperature of the cylinder was measured using an array of k-type thermocouples around the cylinder circumference and recorded in a real-time data logger. The results show that the measured velocity and convection heat transfer coefficient are very sensitive to the frequency of crossflow pulsation. In addition, the influence of pulsating frequency on the local and average of heat transfer coefficient is discussed in detail. Results also demonstrate that maximum enhancement in heat transfer for the horizontal and vertical setup occurs at a frequency of 9 Hz compared to steady forced convection, with 8.33% and 11.11% increment in heat transfer respectively.

Effect of contact temperature, normal load and dry sliding velocity on the coefficient of friction and wear behavior of nickel based super alloy

PurposeThe purpose of the present paper aims to, study the coefficient of friction and wear behavior of nickel based super alloys used in manufacturing of gas and steam turbine blades. In present paper, parametric study focuses on normal load, dry sliding velocity and contact temperature influence on coefficient of friction and wear of a nickel based super alloy material.Design/methodology/approachExperimental investigation is carried out to know the effect of varying load at constant sliding velocity and varying sliding velocity at constant load on coefficient of friction and wear behavior of nickel based super alloy material. The experiments are carried out on a nickel based super alloy material using pin on disk apparatus by load ranging from 30 N to 90 N and sliding velocity from 1.34 m/s to 2.67 m/s. The contact temperature between pin and disk is measured using K-type thermocouple for all test conditions to know effect of contact temperature on coefficient of friction and wear behavior of nickel based super alloy material. Analytical calculations are carried out to find wear rate and wear coefficient of the test specimen and are compared with experimental results for validation of experimental setup. Regression equations are generated from experimental results to estimate coefficient of friction and wear in the range of test conditions.FindingsFrom the experimental results, it is observed that by increasing the normal load or sliding velocity, the contact temperature between the pin and disk increases, the coefficient of friction decreases and wear increases. Analysis of variance (ANOVA) is used to study the influence of individual parameters like normal load, dry sliding speed and sliding distance on the coefficient of friction and wear of nickel based super alloy material.Originality/valueThis is the first time to study effect of contact temperature on the coefficient of friction and wear behavior of nickel-based super alloy used for gas and steam turbine blades. Separate regression equations have been developed to determine the coefficient of friction and wear for the entire range of speed of gas turbine blades made of nickel based super alloy. The regression equations are also validated against experimental results.

Smoke Particle, Polycyclic Aromatic Hydrocarbons and Total Benzo[a]pyrene Toxic Equivalence Emitted by Palm Oil Sewage Sludge Bio-Char Combustion

The size distribution, total particle mass concentration (TPMC), polycyclic aromatic hydrocarbons (PAHs) value, and total Benzo[a]pyrene Toxic Equivalence (BaPTE) concentration of smoke particles from palm oil sewage sludge (POSS) bio-char combustion were studied. In this experiment, temperature data of the POSS bio-char combustion were recorded in two parts: particle temperature (Tp) by using a two-color pyrometer and temperature at 300, 500 and 800 mm, respectively, above the fire base by using K-type thermocouples. The POSS bio-char moisture content, clean air speed values, and burning period affected the change of temperature above the fire base. The mass median aerodynamic diameter (MMAD) values of the POSS bio-char combustion were found to be 0.44 to 1.05 micron at various moisture contents and burning periods. The MMAD, TPMC, and PAHs values increased with increasing moisture content and decreased the POSS bio-char combustion period. For the total BaPTE values, the results showed that the decrease in moisture content of the POSS bio-char samples had a prime influence in decreasing the total BaPTE values. Meanwhile, with decreases in the clean air speed values, the total BaPTE values were increased. Comparing the total BaPTE data between the experimental results and predicted values, the first-degree model had a better fit in predicting than the zero-degree model; this result was confirmed by the higher mean of the coefficient of determination.

An industrial IoT sensor system for high-temperature measurement

The world is changing, with more systems becoming automated through the Internet of Things (IoT). By the end of 2020, 38.5 billion connected devices are expected to be part of the IoT, which is an increase of 25.1 billion from 2015. With the digital revolution thoroughly underway, companies have been fully aware that statistical data can help their businesses thrive and increase efficiency. In this paper, the design and implementation of an Arduino sensor system used to record the temperature and location of ladle vessels for metallurgical purposes is presented. The Arduino microcontroller has multiple modules connected to it, including a K-Type thermocouple, Global-Positioning System (GPS) Shield, Real-time clock, and a Bluetooth module. Additionally, our system was fully tested to demonstrate that it could measure 1220 Celsius for twenty-two hours. Our work can contribute to the development of Industrial IoT and smart sensor services.

An accessible method of embedding fibre optic sensors on lithium-ion battery surface for in-situ thermal monitoring

Presented is a proof of concept to evaluate the suitability of a mounting technique for fibre optic sensors (FOSs) to measure Lithium-ion Battery (LIB) temperature. Two mounting techniques for the optical fibre, i.e. containing multiple Fibre Bragg Gratings (FBGs), placed on the LIB are considered. The FOS results are compared with K-type thermocouples, which are also mounted on the LIB. The first mounting technique attaches the FBGs on to the battery surface using a binding agent, while for the second technique, a “guide-tube” is used for alleviating longitudinal strain in the FOS induced by LIB expansion without the complexity of metal or glass tubes typically used for signal decoupling. The first mounting technique is calibrated over a 40 °C temperature variation to derive the sensitivity factor for each FBG; the other technique uses the free fibre sensitivity obtained by the manufacturer. The LIB is subject to 10 Watts constant power (CW) discharge, inducing 14 °C surface temperature increase. The guide-tube technique proposed in this study improves measurement accuracy from± 4.25 °C to + 2.06 °C when both mounting techniques are directly compared to the thermocouples. The proposed mounting technique is found to be a feasible method for cell-level temperature monitoring applications.

An experimental study of the thermal behavior of bricks integrated with PCM-capsules in building walls

Buildings are the major energy users and by 2035, they will be the fourth largest source of greenhouse gas emissions. Phase change materials (PCMs) are applied to shift the peak-load to the off-peak-load, positively effecting the efficiency of the building. In this paper, an experimental embedding of PCM (Paraffin) with bricks in conventional wall layers is carried out. The effect of this on the thermal diffusion of the inner surface of the wall is studied. Capsules are manufactured to fit the size of the holes inside the bricks and they are filled with Paraffin (147 kJ/kg latent heat, 38oC solidified and 43oC liquidised) and closed in a way that prevents leakage. Each brick contained two rows of holes (5 holes per row). Capsules are placed in the holes at a rate of 5 capsules per brick and 10 capsules per brick. Three wall samples are experimentally tested: traditional wall, wall containing 5 capsules/brick and a wall containing 10 capsules/brick. The indoor test with light intensity has been fixed on 900 W/m2 during the heating period for 4 hours and the remaining period of cooling. The temperature measured and recorded for the internal, external surfaces and the middle of the wall using K-type thermocouples and datalogger. The results indicated that, bricks wall with 10 PCM- capsules per brick reduced the heat flux by 34.17% compared with traditional wall sample, and energy stored 50% more than a wall with 5PCM-capsules per brick. The lowest temperature of the internal wall surface of sample 10 capsules per brick is recorded compared to the reference wall where the difference is more than 3°C.

KARAKTERISASI TERMOKOPEL TIPE K PADA FASILITAS SIMULASI SISTEM FASSIP-02

In the activities of the Pratama Insinas, Ministry of Higher Education technology research in 2018, PTKRN BATAN built a testing facility that simulates a passive cooling system on the reactor core when there is a loss of outside power. The test facility is the Passive-02 System Simulation Facility (FASSIP02).In FASSIP-02 there are several parameters that need to be measured, one of which is temperature. In the measurement of temperature using a K type Thermocouple Connected to the National Instrument 9178 and 9213 modules that use computer programming with LabVIEW software. Temperature measurements need to be characterized.Characterization of type K thermocouples was carried out using thermobaths, 30 type K thermocouples, standard thermocouples,National Instrument modules 9178 and 9213 with computer programming displays using LabVIEW software. The method used for characterization oftype K thermocouples is a fixed temperature comparison method where the results of the temperature control of thermobath is 30-90 ͦC compared with the results of measurements from the type Kthermocouple and standard thermocouple. From the difference of the copper-wrapped junction tip thermocouple without the copper-wrapped and standard thermocouple produces a small error value, so the use of copper as a thermocouple junction end wrapper can be used as a temperature measurement FASSIP-02.

Experimental Study on Axial Temperature Profile of Jet Fire of Oil-Filled Equipment in Substation

With the widespread use of substations around the world, oil jet fire accidents from transformer oil-filled equipment in substations caused by faults have occurred from time to time. In this paper, a series of transformer oil jet fire experiments are carried out by changing the external heat source (30 cm and 40 cm) and the inner diameter of the container (5 cm, 8 cm and 10 cm) to study the axial centerline temperature distribution of the transformer oil jet fire plume of the transformer oil-filled equipment in the substation. The experiment uses K-type thermocouple, electronic balance and CCD to measure and assess the temperature distribution of the axial centerline of the fire plume of the transformer oil jet. The result demonstrates that the axial centerline temperature of the fire plume increases with the external heat release rate and the inner diameter of the container. In addition, a novel axial temperature distribution prediction model of the transformer oil jet fire plume is established. This model can effectively predict the oil jet fire plume temperature of transformer oil- filling equipment in substations, and provide help for substation fire control.

Heat Generation and Temperature Control during Bone Drilling for Orthodontic Mini-Implants: An In Vitro Study

Background: The purpose of our in vitro study was to evaluate the impact of different irrigation fluid temperatures in combination with different drilling speeds on intraosseous temperature changes during mini-implant site preparation. Methods: Porcine ribs were used as bone specimens. Grouping determinants were as follows: irrigation fluid temperature (10 and 20 °C) and drilling speed (200, 600, 900, and 1200 RPM). The axial load was controlled at 2.0 kg. Temperature measurements were conducted using K-type thermocouples. Results: Extreme increments were observed only in the unirrigated groups. Irrigation invariably made a significant difference within groups defined by the same drilling speed. The comparison of the different temperature irrigation fluids (10 and 20 °C) in combination with the same drilling speed (200, 600, 900, or 1200 rpm) resulted in a statistically significant difference between the two different temperatures, whereas the use of irrigation fluid at a controlled room temperature of 20 °C showed significantly higher temperature changes. Conclusions: Based on the results of the study, we conclude that irrigation while preparing a pilot hole for a self-tapping orthodontic miniscrew is of utmost importance, even at low drilling speeds. The temperature of the cooling fluid does influence local temperature elevation to a significant extent.

Effect of Three Different Cooling and Insulation Techniques on Pulp Chamber Temperature during Direct Temporization with Polymethyl methacrylate-based Resin

This in vitro study evaluates and compares the changes in pulp chamber temperature during direct fabrication of provisional restorations in maxillary central incisors after using three different cooling techniques. Total of 60 samples of maxillary central incisors along with their putty indices were divided into four groups (one control and three experimental) and were prepared using a surveyor cum milling machine. Teeth were sectioned 2 mm below cementoenamel junction and a K-type thermocouple wire was inserted in the tooth and secured at the pulpal roof using amalgam. Putty index filled with DPI tooth molding resin material [polymethyl methacrylate (PMMA)] was placed on the tooth and temperature changes per 5 seconds were recorded by temperature indicating device for the control, on-off, precooled putty, and dentin bonding agent (DBA) group. The highest mean obtained was of the control (11.04°C), followed by DBA group (9.53°C), precooled putty group (6.67°C), and on-off group (1.94°C). Precooled putty index group took maximum time to reach the baseline temperature (847.5 seconds). On-off technique is the most effective method to reduce the intrapulpal temperature during polymerization, as compared to the other techniques used in the study. Retardation in the polymerization process was seen in precooled putty group, which may make this technique clinically inadvisable. Thermal protection of pulp must always be considered during direct fabrication of provisional restoration when a PMMA-based resin is used. By using on-off technique, not only the thermal insult to the pulp can be effectively minimized but also the harmful effects of residual monomer (poor marginal fit and pulpal irritation) can be eliminated.

Experimental, analytical and numerical, investigation of peak temperature and cooling rate in butt joint weld of mild steel

PurposeThis paper aims to measure peak temperatures and cooling rates for distinct locations of thermocouples in the butt weld joint of mild steel plates. For experimental measurement of peak temperatures, K-type thermocouples coupled with a data acquisition system were used at predetermined locations. Thereafter, Rosenthal’s analytical models for thin two-dimensional (2D) and thick three-dimensional (3D) plates were adopted to predict peak temperatures for different thermocouple positions. A finite element model (FEM) based on an advanced prescribed temperature approach was adopted to predict time-temperature history for predetermined locations of thermocouples.Design/methodology/approachComparing experimental and Rosenthal analytical models (2D and 3D) findings show that predicted and measured peak temperatures are in close agreement, while cooling rates predicted by analytical models (2D, 3D) show significant variation from measured values. On the other hand, 3D FEM simulation predicted peak temperatures and cooling rates for different thermocouple positions are close to experimental findings.FindingsThe inclusion of filler metal during simulation of welding rightly replicates the real welding situation and improves outcomes of the analysis.Originality/valueThe present study is an original contribution to the field of welding technology.

Concise characterization of cold atmospheric pressure helium plasma jet

This article provides a concise methodology for the development of a cold atmospheric pressure plasma jet and its characterization. To optimize the plasma jet parameters for biological and industrial applications, it is highly necessary to thoroughly understand its characteristics. The major emphasis of this work is to utilize simple and advanced diagnostics systematically with low complexity in the post-data analysis and to obtain in situ information of plasma jet parameters. The detailed optimization methods and the effect of the applied voltage and gas flow rate to achieve the stable plasma jet of the desired dimensions are discussed. In addition, the effects of the gas flow rate on the discharge current profiles and filament behavior are provided. Moreover, optical techniques, such as optical emission spectroscopy and time-resolved fast imaging, are used for the characterization of plasma parameters, i.e., Texc and ne, in a simple way. The gas temperature along the length of the plasma jet is estimated using a K-type thermocouple. The discussed simple characterization techniques and range of parameters of our designed plasma source will be useful for the development and optimization of plasma jet sources for various biological and industrial applications. Furthermore, we have also discussed various applications where we can use the discoursed diagnostics for the system development as well as for characterization. As the characterization of cold atmospheric pressure plasma jets is a multiphysics study, this concise characterization report on the cold atmospheric pressure plasma aims to provide necessary information for early researchers.

A hybrid thermal management system for high power lithium-ion capacitors combining heat pipe with phase change materials

Lithium-ion capacitor (LiC) technology is an energy storage system (ESS) that combines the working mechanism of electric double-layer capacitors (EDLC) and lithium-ion batteries (LiB). When LiC is supposed to work under high power applications, the inevitable heat loss threatens the cell's performance and lifetime. Therefore, a proper thermal management system (TMS) can remove the generated heat of the LiC during high cycling conditions. In this paper, a hybrid TMS (HTMS) using phase change materials (PCM) and six flat heat pipes is proposed to maintain the temperature profile below 40 °C under a high current rate of 150 A for 1400 s profile without any pause. Two K-type thermocouples (T1 & T2) are responsible for monitoring the experiments' temperature evolution in the experiments. Numerical analysis is also performed and verified with experimental results to analyze the temperature profile numerically. The experimental and numerical simulation comprises three case studies, including the cell's temperature under natural convection, temperature distribution when using the heat pipe TMS, and temperature distribution when using HTMS. The results reveal that the HTMS is an exceptionally robust cooling system since it reduces the T1 temperature by 35% compared to the natural convection case study, while the heat pipe TMS can reduce the T1 temperature by 15% compared to the same case study.

HEAT GENERATION DURING IMPLANT PLACEMENT IN HIGH-DENSITY BONE: EFFECT OF DIFFERENT DRILLING TECHNIQUES

ABSTRACT Introduction: A precise drilling-sequence-protocol is essential for long-term dental implant success in high bone density (mandibular cortical bone of D1-quality). Cone beam computed tomography (CBCT) radiographic imaging and CBCT-based construction of surgical guides have been substantial for diagnosis and treatment planning. Objectives: The study aimed to measure the effect of different guided drilling techniques on the amount of heat generated during implant placement in high density. Materials and Methods: Twenty-four osteotomies for implant placement, divided equally into three groups, to test the effect of the three drilling techniques Undersized Drilling (UD), Undersized Drilling + Ridge Spreader size 4 (UD+RS4) and Undersized Drilling + counter sink size 4 (UD+CS4) techniques. Heat generation was assessed using K-type thermocouple. Drilling and thermocouple canals were guided by the surgical template. Bone assessment, virtual planning of the implants and surgical guide construction were based on radiographic CBCT-imaging and software-based processing. Insertion torque values (ITVs) were recorded from readings of a geared motor. Results: The thermocouple results showed the least significant difference at 10 mm depth. At 5mm depth, a significant decrease in the temperature difference of the UD+RS4 group and UD+CS4 group compared to UD group was observed. At 1mm depth, there was a significant difference between the UD group and the two other groups. The UD group showed the maximum peak ITV. Conclusion: the results suggest possible advantages when self-tapping implants are inserted into high density cortical bone of D1-quality by a countersink drill since it provides lesser temperature increase at insertion.

UNCERTAINTY QUANTIFICATION USING THERMOCOUPLE AND ARDUINO® COMPATIBLE HARDWARE

Temperature is a critical aspect in the control of processes in engineering. The measurement, however, must take into account not only the accuracy of the sensor but also the implementation costs and uncertainty. Thermocouples are one of the most widely used temperature measurement methods combining low costs, high measurement ranges, and relatively good accuracy. The acquisition system, however, is usually expensive. This paper evaluated the uncertainty in the temperature measurements of a K-type thermocouple using low cost Arduino® compatible hardware as a data acquisition system. This set was calibrated using a thermostatic distilled water bath at both freezing and boiling phase change points. The equations for uncertainty calculation were fully developed, and the procedures described serve as a reference for uncertainty assessment for thermocouples with other data acquisition systems. Although the calibration was the most significant contributor, the low variability of measurements shows the system has good stability and is a fine choice for industrial applications. The calculations are easy to implement as a routine for several measurements and guarantee results up to the international reference standard.

TempSense: A Four-Channel Temperature Logger Based on a USB Bridge and CircuitPython

Accurate temperature measurements are needed to monitor and reduce energy use and greenhouse gas emissions in building, industrial, and other processes. This paper describes a temperature sensor instrument, named TempSense, developed for classroom demonstrations of thermal phenomena. The instrument can monitor, record, and visualize data from multiple temperature sensors using a K-type amplifier and thermocouples. It has an accuracy of ±2 deg C from -200 to +700 deg C and an accuracy of ±6 deg C from –270 to +1372 deg C. The instrument uses a USB bridge and the Python language to interface with open-source thermocouple amplifiers without the need for byte-level programming. Its design allows novice experimenters to inspect the build and operation and even customize it to their needs. TempSense can be extended via Python libraries to provide internet communication, visualization, and analysis.

Prediction of Size Distribution and Mass Concentration of Smoke Particles on Moisture Content and Combustion Period from Para Rubber Wood Burning

The size distribution and total particle mass concentration (TPMC) of smoke particles from para rubber wood (Hevea brasiliensis) combustion in the ribbed smoked sheet (RSS) process were studied. In this experiment, temperature data values of para rubber wood combustion were recorded at 500 mm above the base of the fire by K-type thermocouples. The wood moisture content and wood combustion period were used to find and improve an equation of smoke particle size distribution (SPSD) and TPMC by the response surface method (RSM). An eight-stage Andersen air sampler and a high-volume sampler were used to measure and calculate SPSD and TPMC, respectively. Resulting data in this experiment showed that TPMC ranged from 3.12 to 77.42 mg/m3. SPSD was single mode in which MMAD, mass median aerodynamic diameter, ranged from 0.64 to 1.27 microns for para wood with moisture content ranging from 31.5 to 89.7% dry weight basis. The combustion period and moisture content of para wood have a direct effect on the change of temperature data above the base of the fire and the TPMC and MMAD values. For predicting TPMC and MMAD values by the para wood moisture contents in each combustion period, the results found that the second-degree model was a better plot than the first-degree model, confirmed by higher values of the coefficient of determination (R2).

The set Up of an Experimental Testing Rig to Measure Time and Space Temperature Profiles in Laser Sintering of Polymeric Powders

Selective Laser Sintering (SLS) is the most common type of Additive Manufacturing (AM) process using granular materials which has the potential to revolutionize the manufacturing industry. However, in the layer-wise build-up of the three-dimensional specimen, the complex laser-material interactions and the poor selection of associated process parameters can give rise to an increase to a number of defects of the artifacts. In fact, the temperature distribution along the surface and in depth at the laser spot, which are strongly affected by the thermal conductivity of the powder bed, do affect the hatch distance and the thickness of the powder layer, as well as on the quality of the final artifact. In this study, a laser sintering experimental set-up, equipped with an Infra-red thermographic camera and a K-type thermocouple, is built to measure the temperature distribution at the surface and 1mm below the surface in a special Polyamide 12 (PA12) powder bed. A one-watt stationary diode laser is used as heat source on samples characterized by various particle size distributions (PSD). Using the set-up, an accurate in-situ thermal characterization of the powder bed along with heat distribution study can be performed. Preliminary tests were conducted and the pixelwise temperature profile along the surface and temperature at the depth of 1mm below the surface of the powder bed has been reported. On the basis of the results, it is possible to provide good estimates of the global energy balances on the system, which are essential in evaluating the energy required to optimize the sintering and melting process of the polymeric powders.

A comprehensive numerical investigation of unsteady-state two-phase flow in gravity assisted heat pipe enclosure

In this study, thermal performance analysis of glass and copper two-phase closed thermosyphons (TPCTs) were investigated as 3D using comprehensive experimental methods and a new combined numerical model containing two stages. For this purpose, Volume of Fluid model has been used for the first 60 s, and Eulerian model has been employed after 60 s until 180 s for the first time in the literature. For the verification of this numerical analysis, the surface temperatures of TPCTs were measured at twenty different points by K-type thermocouples. The pressure change inside the pipes was measured by a vacuum manometer. A video camera was utilized to observe the change of steam and water volumes in the glass TPCT. The experimental and numerical results were also compared with each other in real-time for the first time in the literature. According to results, the numerical temperature distributions and steam volumes in TPCTs have shown a similar trend with the studies in the literature. It was observed that the maximum absolute temperature difference values in the evaporation, middle and condenser regions for TPCTs ranged from 6.81 K to 18.63 K. These values are similar to the values in the other studies. The maximum absolute temperature difference values were calculated between 12.09 K and 26.07 K for different turbulence models.

Experimental study on heat transfer characteristics of closed thermosyphon at different volumes and inclination angles for variable vacuum pressures

In this study, the thermal performance of vacuumed copper pipe has been experimentally investigated by using different volume values of 5 ml, 10 ml, 15 ml, and 20 ml with inclination angles of 45°, 60°, and 90° for variable vacuum pressures. For this purpose, the inner, outer diameter, and length of the vacuumed pipes filled with the distilled water were 26 mm, 28 mm, and 1500 mm, respectively. This copper pipe was vacuumed until the absolute pressure of 6.32 kPa and immersed in a heat source at a constant temperature of 82°C at the beginning of the experiments. The surface temperatures of the vacuumed pipes were measured at twenty different points by using K-type thermocouples in two different data loggers. All calculations were performed as variable saturation temperatures at variable vacuum pressures with changing the time. According to the results, the experimental boiling heat transfer coefficients showed a good agreement with the correlations in the literature. Also, the best thermal resistance was obtained in the vacuumed copper pipe with a water volume of 10 ml at the inclination angle of 90° until the end of the experiment.