Average Temperature Distribution Research Articles

Quasi-one-dimensional approach to heat transfer: General formulation and its application to transformer windings

A quasi-one-dimensional approach to conduction heat transfer with convective boundary conditions is developed for bodies of variable geometry. The novelty of the method is demonstrated on the windings in oil-filled distribution transformers with partial cooling ducts. We obtain analytical solution for the windings average temperature rise and tangential temperature distribution and find them in an excellent agreement with the FEM simulation, numerically confirming the validity of the reduction from 2D to 1D. When the quasi-one-dimensional approach is applied to calculation of temperature rise for the low and high voltage windings in industrial setting we obtain 1% and 5% discrepancy with the industrial tests respectively. Hence, the method offers reliable estimates of the temperature rise, and temperature distribution in a chosen direction, in bodies of variable geometry.

Investigation of pin and perforated heatsink cooling efficiency and temperature distribution

AbstractThe uneven temperature distribution resulting from thermal stresses in heat sinks is a significant issue in modern electronic devices. This numerical investigation utilizes fluid to analyze the cooling, flow, and heat transfer characteristics of eight different heat sink designs. These include pin–fin heat sinks with circular, triangular, square, and hexagonal cross-sections, as well as their perforated versions. The results show that the thermal resistance range for all geometries was between Rth = 0.29 and 0.51 K W−1. The circular cross-section pin structure was found to be the most efficient in terms of thermal resistance, while the triangular perforated structure was the least efficient. The narrow and low temperature distribution indicates a high cooling potential for the heat sink. It has been observed that the temperature range studied is between 308.732 and 315.273 K. The circular cross-section pin structure is most efficient in terms of homogeneous distribution between 308.73 and 311.306 K. The pin-type structure with a square cross-section attained the maximum Performance Evaluation Criteria (PEC) of 1.1872 at P = 689 Pa, while the pin-type structure with a triangular cross-section attained the lowest PEC of 0.67 at P = 2750 Pa. The investigation revealed that, in relation to PEC, perforated structures had superior performance compared to other pin designs, except for the square-section pin structure. This research found that measuring the efficiency of a heat sink based just on thermal resistance or average temperature distribution is not enough; the PEC criteria must also be taken into account.

Development and analysis of temperature rolling model during reversing mill rolling

It is shown that the process of the formation of the structure and mechanical properties of plates products is determined by the change of the temperature of the roll through the stages of the production process in the line of a reversing plate mill. An analytical temperature model is developed, that allows to estimate the distribution of surface and average mass temperature along the length and width of the roll for various stages of rolling with intermediate cooling, considering the deformation conditions for each pass. The temperature model is tested; as result, the proposed model can be used to calculate the distribution of the average mass temperature along the length and width of the roll at various stages of the production of plates on reversing mills.

Evaluation of the earth-air heat exchanger's performance in improving the indoor conditions of an industrial poultry house using computational fluid dynamics verified with field tests

This paper aims to investigate the performance of an Earth Air Heat Exchanger (EAHE) to improve the indoor conditions of an industrial poultry building after its installation, considering the optimal position and installation configuration (separate or collected inlets), which have not been addressed previously. In this regard, an industrial broiler house containing 20,000 chickens equipped with four cooling pads operated by a mechanical ventilation system located in Biskra, Algeria, was simulated with six scenarios, including the original. The model developed is verified with the field test measurements and experimental and numerical data in the literature. The results showed that optimizing the cooling pad position increases average indoor air temperature and velocity distribution by 0.1% and 8%, respectively. Moreover, the position and configuration of installing the EAHE inlets play an important role in uniforming indoor air distribution. Scenario 3, with 80 EAHE inlets versus exhaust fans, has the best indoor air uniformity, with a maximum velocity and temperature difference between its sections of 1.15 m s−1 and 1.4 K, respectively. Overall, EAHE showed a good ability to cool and maintain appropriate indoor air temperatures, achieving a difference of 15 °C between inside and outside, in addition to providing annual energy savings of 921,600 kWh/year and reducing 30,643 tons of CO2 emissions during its lifespan, in contrast, its simple payback time estimated 4 years.

Energy and exergy analysis of latent heat storage with heat pipe encased in phase change material

Loop heat pipe (LHP) encased in phase change material (PCM) incorporated annular to catalytic converter (CC) is proposed to augment the performance of the “thermal energy storage” (TES). LHP are designed to extract surplus heat from the exhaust discharge, thereby reducing the amount of exhaust heat emitted into the atmosphere. A four-cylinder IC engine’s CC is considered with Mg70Zn24.9Al5.1, paraffin oil as PCM and working fluid for the heat pipe are evaluated. A comparative experimental investigation was performed considering two models for CC with and without heat pipe integrated in the TES for (i) distribution of average PCM temperature (ii) energy, exergy efficiency and distribution (iii) effectiveness (iv) instantaneous waste heat recovered during heat storage. Transient cycles at 2000 r/min with varying load conditions were run considering city drive conditions. Heat storage for CC with heat pipe encased in TES was found to be 35% faster, whereas discharge time for CC without heat pipe developed in TES was found to be longer. For melt fraction 1, maximum exergy efficiencies of 71% and 69% were observed for the TES unit with and without heat pipe. Heat pipes are observed to help extract a considerable amount of surplus heat from exhaust and reduce the exhaust gas outlet temperature released into the atmosphere by nearly 130 – 40°C under various load circumstances.

Neural Network and Regression Methods for Estimation of the Average Daily Temperature of Hyderabad for the Years 2018-2020

A qualitative study on temperature distribution has been executed in Hyderabad by several researchers. This study, however, is the first attempt to study temperature distribution quantitatively. Two different methods, i.e., Artificial Neural Network (ANN) and Regression Analysis (RA), have been used to determine the average daily temperature distribution for Hyderabad, a city in Pakistan. Both the methods are used to predict the average daily temperature of the years; 2018, 2019, and 2020. In Neural Network (NN) analysis, the network was trained and validated for three years with temperature recorded from 2015-2017. With the help of training and validation parameters of the hidden layer, the average d aily temperature was predicted for 2018-2020. Based on input parameters (dew point, relative humidity, and wind speed), a multiple regression model was developed, and average daily temperature for the years 2018-2020 was predicted again. For validation of the model statistical errors, Root Mean Square Error (RMSE), Mean Absolute Error (MABE), Mean Absolute Percent Error (MAPE), and coefficient of determination are calculated. The statistical errors show that multiple regression models and neural network models provide a good prediction of temperature distribution. However, the results of the neural network are better than the regression model.

Application of Combined Micro- and Macro-Scale Models to Investigate Heat and Mass Transfer through Textile Structures with Additional Ventilation

In this study, computational models of heat and mass exchange through textile structures with additional ventilation at the micro- and macro-scale were investigated. The finite element analysis of advanced textile materials provides a better understanding of their heat and mass transfer properties, which influence thermal comfort. The developed computational models can predict air permeability (AP), thermal resistance (Rct), and heat transfer (h) coefficients at the micro-scale. Moreover, the mesh size was taken into consideration and validated with experimental data presented in the literature. In addition, computational models were extended to micro- and macro-scale forced ventilation models. Macro-scale finite element models require input parameters such as an effective heat transfer coefficient that are usually obtained experimentally. In this research, the heat transfer coefficients (hmicrolayer = 25.603 W/(K·m2), htotal = 8.9646 W/(K·m2)) were obtained numerically from the micro-scale model and were applied to a macro-scale model. The proposed methodology and developed models facilitate the determination of average temperature and temperature distributions through different through-thickness positions along the axis Oz. The simulations were carried out using Comsol Multiphysics and Matlab software.

Solidification performance improvement of phase change materials for latent heat thermal energy storage using novel branch-structured fins and nanoparticles

In the present study, we propose the combination of novel branch-structured fins and Al2O3 nanoparticles to enhance the performance of a phase change material (PCM) during the solidification process in a triple-tube heat exchanger. The inevitable drawback of PCMs is their lower heat conductivity, which can result in a long response time during the phase change process in latent heat thermal storage systems. Therefore, any serious improvement strategy needs an optimized phase change process. A mathematical model for a two-dimensional structure composed of a PCM with paraffin RT82 and Al2O3 nanoparticles that considers the thermal conduction in metal fins, Brownian motion of nanoparticles, and natural convection in a liquid phase PCM is proposed and verified based on experimental results. The impact of various volume fractions and fin layouts on the solidification process is discussed, involving the evolution and deformation of solid–liquid interfaces and distribution of isotherms and average temperature and liquid fraction curves. The results imply that the solidification behaviour can be significantly enhanced by the application of nanoparticles and metal fins. Compared with the inherent structure of the heat exchanger, the solidification time is decreased by 8.5%, 9.3%, and 10.3% for Al2O3 nanoparticles (at 2%, 5%, and 8%, respectively) only and by 83.0%, 80.7%, 80.8%, and 82.9%, respectively, for various fin layouts only. This is attributed to increased heat transfer by thermal conduction and natural convection. It can be concluded that the impact of the use of fins is preferable compared to that for nanoparticles, and the benefit of nanoparticles is limited.

Highly efficient photonic PCR system based on plasmonic heating of gold nanofilms

The polymerase chain reaction (PCR) is a standard molecular method that has the potential to solve the need for accurate, viable, and immediate infectious pathogen detection at point-of-care (POC) centers in different fields such as pathogen identification, and forensics. In this work, we present a photonic PCR thermocycler that achieves strong optical absorption, more efficient gene amplification, and further improves the effect of temperature distribution through the PCR sample using two gold nanofilms (AuNFs) and a high-power light-emitting diode chip (LED). The photonic device achieved higher heating and cooling rates of 13.20 null°C/s and 7.92 null°C/s, respectively on average, with uniform and reliable temperature distribution throughout the sample with negligible deviations. During amplification cycles, maximum temperatures attained had variations less than 1 °C at 90 °C, less than 0.8 °C at 55 °C, and less than 0.5 °C at 72 °C, showing uniform heating which yielded more accurate and reliable results. Using the fabricated device, PCR amplification for a bacteria genomic DNA was performed in 7.5 minutes for 30 thermal cycles with a sample volume of 20 μL. Due to the device's simple configuration and increased heat transfer rates, this photonic platform will be a highly efficient choice for rapid POC applications in developing countries.

Performance analysis of series connected cathode supported tubular SOFCs

The long current conduction path of traditional tubular solid oxide fuel cells (SOFCs) limits the output performance. A new series connection structure was proposed, and a three-dimensional model of this series tubular solid oxide fuel cell was developed on the premise of keeping the reactant channel area unchanged, the thickness of electrodes and electrolytes distributed in the original proportion. The effects of the series structure on the distribution of species, average temperature and electrical properties of the cell were studied, and the model cases of different flow modes are developed to explore their influence. The models and results of this study are compared with those of previous studies. The results of simulation show that compared with traditional tubular SOFC, the average current density of the new series SOFC and the new series SOFC with cooling is increased by 18.12% and 9.28% respectively in the co-flow, and the peak power density is increased by 431.94 W/m2 and 211.73 W/m2 respectively. The maximum temperature is reduced by nearly 160 K after the cooling channel is added, showing excellent performance at low temperature. The study concluded that the current conduction path is shortened by using new series, the conduction resistance and ohmic losses are reduced, the added multiple connectors further improve it. The output performance of SOFC is improved by using new series. The heat transfer of new series connection SOFC has been enhanced, and the heat generated by the reaction can be fully exchanged by the adding cooling channel, which reduces the average temperature of the cells during operation, it provides a reference for commercial and practical applications.

Road performance and thermal-insulation effect in construction of asphalt mixture containing phase-change thermal-insulation agent

Highway construction strategies impact the early damage of asphalt pavement and its sustainability. The pavement quality is directly influenced by the temperature of the asphalt mixture during paving and rolling, but delaying the cooling of the mixture at this stage has rarely been investigated. An asphalt mixture modified with a phase-change thermal-insulation agent (PCTIA) was prepared potentially improve the temperature of the asphalt mixture during construction. The high-temperature, low-temperature, and water-stability performance of asphalt mixtures with different PCTIA contents were analysed. The temperature regulation test was carried out, and the temperature field model of the asphalt pavement paving process was established. Based on the laboratory test and FEM models, the influence of different construction environmental conditions on the thermal-insulation performance of PCTIA and its thermal-insulation mechanism were analysed by using the distribution of temperature, average temperature, and equivalent temperature. The thermal-insulation effect of PCTIA was quantified by latent heat accumulated temperature value (LHATV). Results show that PCTIA improves the high and low-temperature performance of asphalt mixture, and has little effect on water stability. The best overall road performance is achieved at 2.5% PCTIA content. PCTIA can significantly reduce the cooling rate of asphalt mixture, and the distribution of temperature difference and time difference is obviously different in different positions of loose asphalt mixture layer and different external environments. Latent heat accumulated temperature value (LHATV) can characterize the phase-change insulation effect of PCTIA well. The wind speed increases and air temperature-bottom temperature decreases reduced LHATV indicating that too rapid cooling of asphalt mixture would weaken the thermal-insulation performance of PCTIA. Both average temperature and equivalent temperature can reflect the thermal-insulation effect of PCTIA, where the average temperature can be used to analyse the specific phase-change process of PCTIA in asphalt mixture and then analyse the insulation mechanism of PCTIA. Combining average temperature and equivalent temperature, PCTIA had the most application value in low temperature and low wind speed environments. This study aims to explore the effective method of delaying the cooling of high-temperature asphalt mixture from the perspective of phase-change energy storage and explain its mechanism.

State-of-the-arts Thermal Management Systems for New Energy Vehicles

With the rapid progress of automobile manufacturing industry, people's demand for energy is gradually expanding, and smog is gradually appearing in cities. New energy has gradually become a new direction of automobile development, with its dual advantages of not only reducing emissions but also saving energy. Lithium battery is the main component of new energy vehicle, and its temperature will be in the heating process of current input and loss. The average temperature distribution directly affects the service life and functional effect of the battery, and the stability of the battery determines whether it can bear much power. If the car is running, the heat of the battery can't be dispersed in time and the local temperature is too high, the life of the battery will be reduced rapidly, and even more seriously, it will lead to fire. Therefore, in order to make the battery pack of the new energy vehicle heat evenly, and the reliability and safety of the new energy vehicle work continuously and effectively, A battery heat dissipation structure is determined in order to improve the overall performance of the lithium-ion battery. The latest thermal management systems for new energy vehicles are thoroughly examined in this paper.

Mapping and Analysis of Monthly Average Maximum and Minimum Air Temperature Distribution of Muğla Province in Geographic Information Systems (GIS) Environment with IDW Method

Muğla province, which is located in Southwest Anatolia and has a surface area of 13,338 km2, generally has a mountainous and rough terrain. In this study, it is aimed to map and analyze the distribution of monthly and annual maximum and minimum average temperature values of Muğla province by using the Inverse Distance Weighted (IDW) interpolation method. For this purpose, meteorological data of 13 stations of the General Directorate of Meteorology in Muğla and the stations of Gölhisar, Bozdoğan, Kaş, Elmalı, which are close to the borders of the province, were used. The average values of the annual and monthly maximum and minimum temperatures of these stations were transferred to the ArcGIS environment with the help of Geographic Information Systems (GIS) and their distribution was mapped with the IDW method. According to these maps, the highest average annual temperature in Muğla is in Milas and its surroundings, while the lowest is the provincial borders in the northeast of Muğla center and Seydikemer district. These two places are followed by Datça district, which is located on a long peninsula. The places with the highest annual minimum average temperatures are around Datça and Marmaris districts, while the lowest is the Burdur provincial border in the northeast of Kavaklıdere and Seydikemer. The maximum average temperature in the province is July (between 41.6-41.1°C in Milas and Köyceğiz), and the lowest is January (between 14-17°C in Muğla center and Kavaklıdere). The minimum average temperatures in the province are highest in June (between 37.7-34.6°C in Marmaris), and the lowest in January (between -7.9 and -6.6°C in Kavaklıdere). Elevation conditions, maritime influence and aspect conditions, and the intrusion of thermal pressure areas, especially in summer, have been effective in the distribution of maximum and minimum average temperature values in the province. These values may also vary depending on time during the year

Открытые источники данных для моделирования ареалов: информационные системы о биоразнообразии и наборы пространственных данных условий среды

Открытые источники данных для моделирования ареалов: информационные системы о биоразнообразии и наборы пространственных данных условий среды

Numerical study the effect of air barriers height inside the air conditioning ducting to satisfy the regulation of Indonesia Minister of Transportation number 69 of 2019

The Indonesian smart hybrid light train is a train under development by the government and will operate in Makassar-Parepare, Indonesia track. The authors conducted a numerical study on CFD to investigate the air flow distribution inside the air conditioning ducting and the air velocity and air temperature distribution on Motor Engine and Compartment (MEC) car to achieve the passenger comfort criteria based on the regulation standard of Indonesia Minister of Transportation Number 69 of 2019. This study was conducted by simulating 5 variations of air barriers height inside the supply ducts. The input of air into the ducting has the parameters of mass flow rate, static temperature, static pressure, and density with the values of 1 kg/s, 20 °C, 1 atm, and 1.2 kg/m 3 , respectively. The simulation results show that variation E is the best design which generated the average air velocity and air temperature distribution in the executive passenger cabin with the values of 0.25 m/s and 21.91 °C, respectively. Meanwhile, the other 4 variations did not satisfy the standard. The results also show that the ducting geometry can accommodate the air temperature difference on the MEC car that does not exceed 1.5 °C and the air supply is sufficient from the air conditioner unit to the driver room.

Changing climatic indicators and mapping of soil temperature using Landsat data in the Yangan-Tau UNESCO global geopark

Changes in key climate index affect ecosystems and biodiversity. In this regard, the assessment of the climatic conditions is of particular relevance. This study presents the results of an analysis of climate change and digital mapping of soil temperature in the Yangan-Tau UNESCO Global Geopark (Russia). The steady increase in air temperature was revealed, which causes an increase in the sum of active temperatures and the duration of the warm period of the year. Annual total precipitation during 1966-2020 changed the sign of the trend: positive trend (increase in precipitation) in 1966-1990, while in 1991-2020 is negative. The hydrothermal indicators determined the increase in aridity during the warm period. Based on the analysis of changes in the climatic conditions of the geopark, a comparison was made of the temperature regimes of air and soil, and the relationship between these indicators in the snow-free period was revealed (R2 = 0.62). An approach is presented for digital mapping of the temperature regime of the surface layer of soils based on ground-based research data and the results of interpretation of the Landsat thermal bands. A significant relationship between soil temperature and Earth surface temperature for the snow-free period was revealed (R2 = 0.83). Based on the obtained regression model and Landsat 8-9 data for the snow-free period of 2013-2022 the map of the distribution of average temperatures of the surface layer of soil from May to October was produced, which clearly demonstrated the relationship between soil temperature and biomes. Keywords: soil temperature; surface land temperature; remote methods; climate change; Yangan-Tau UNESCO global geopark; Bashkortostan.

STUDY OF THE TEMPERATURE DISTRIBUTION IN A PARABOLIC CYLINDRICAL CONCENTRATORUSING A NANOFLUID AS HEAT TRANSFER FLUID

We have numerically studied the heat transfers in a Cylindrical-parabolic concentrator using a nanofluid as heat transfer fluid for its use in Solar Thermodynamics. After an analysis of the work relating to solar concentrators and nanofluids, we have, after having described our physical system and posed working hypotheses, written the equations which govern the transfers in our collector. The latter as well as the associated boundary conditions were then dimensionless in order to generalize the problem and reveal the parameters that control the operation of the absorber. To solve our equations, we used the method of finite differences and the algebraic system obtained is solved thanks to the Thomas method combined with an iterative process of line-by-line relaxation type. The computer code that we developed made it possible to find the temperature distributions according to the spatial coordinates and at different times. The effects and influences of wind effect, axial and transverse thermal dispersion, absorber length, geometric shape factor on the average temperature distributions of the coolant is analyzed. At the end of the study, we were able to identify the most important physical and geometric parameters which give our system optimum operation for its use in Solar Thermodynamics.

Climate of the Pokuttia and Bukovyna Carpathians and foreland in the second half of the 19th – at the beginning of 20th centuries

Climate reconstruction of the Pokuttia and Bukovyna Carpathians, its foreland and adjacent mountain and foothill areas in the 19th century is performed due to a dense network of meteorological observations, starting from the 60s of the 19th century in the Bukovyna and Galychyna provinces within the Austrian Monarchy and several paleoclimatic reconstructions, mainly dendroclimatic, carried out on the basis of data collected in the Eastern Carpathians. Spatial interpolations using universal kriging has been performed based on in-situ homogenized data of weather stations of the second half of the 19th century – the first half of the 20th century. The longest series of observations in the city of Chernivtsi since 1852 has enabled to track multidecadal changes in average annual and monthly air temperatures and atmospheric precipitation. The centennial course of these climatic indicators corresponds to the general patterns characteristic of all the Eastern Carpathians with the most pronounced continentality among the rest of the Carpathian regions. Cold decades in the second half of the 19th century in Chernivtsi are considered the continuation of the coldest period of 1720–1850 in the Eastern Carpathians in the last 600 years. The spatial distribution peculiarities of average monthly temperatures in the second half of the 19th – at the beginning of 20th centuries in the region are manifested in a pronounced orographic steplike isotherm pattern. In the second half of the 19th century – the first half of the 20th century, the average long-term temperatures ranged from +3.5 to +4 °C in the southwest to +8 °C in the north and northeast in accordance to the orientation of the mountains. Inversion features of the valleys and internal lowlands are revealed in the spatial distribution of average temperatures, especially in the summer months. These features are also distinguished by a lower amount of atmospheric precipitation in the dry months of spring and autumn. Spatial distribution of temperature and precipitation in the second half of the 19th century – at the beginning of 20th century is also distinctive in the the inner mountain ridges of the adjacent Hryniava and Chornyi Dil mountains. These mountains are founded to be the coldest, often with a lack of meteorological summer and a maximum of precipitation in the spring and autumn months. A comparative analysis of the spatio-temporal distribution of average multi-year air temperatures and precipitation at the turn of the 19th and 20th centuries was performed. In general, similar distribution of air temperatures and precipitation is revealed. The differences are more noticeable in the monthly context, especially in summer and in the mountainous parts of the region. Comparing the turns of 19th and 20th centuries, the average July monthly temperature in the southernmost mountain massifs of the region has increased by 1 °C, while in the foothills the increase does not exceed 0.5 °C. In the annual context, changes are less noticeable. The range of air temperature changes from north to south is the same at the turn of both the 19th and 20th centuries. The city of Chernivtsi is founded to become a bit warmer (by 0.5 °C), but interannual fluctuations of annual air temperatures within 2 °C are typical throughout all the centuries. Alongside, high annual temperatures (+9 °C and higher) have been observed more often. While in the last century such temperatures were recorded once per 5–10 years, in the first decade of this century, annual temperature above +9 °C is recorded every second year. Short-term fluctuations (5–10 years) of annual precipitation amounts have been characteristic of the whole period since the 19th century. The interpretation of local climatic differences involves further devolopment of accurate interpolation techniques and downscaling, especially for the construction of precipitation field given lack of high-mountain weather stations in the earlier centuries. The latter corresponds to the future studies of the author.

Pore-scale direct numerical simulation of fluid dynamics, conduction and convection heat transfer in open-cell Voronoi porous foams

The pore-scale analysis includes the pore network simulation and direct numerical simulation, which the latter is more accurate and provides more details about the problem. This study presents a pore-scale direct numerical simulation of flow and convection-conduction heat transfer in open-cell metal foams with a complex structure. First, using the Laguerre–Voronoi tessellations (LVT) algorithm, three foam samples with various porosities (76.6%, 84.4%, and 93.8%) and a constant pore density of 20 pores per inch (PPI) are generated. Next, the open-source library of OpenFOAM is employed to perform heat transfer and flow analysis in Darcy and non-Darcy regimes. Results were verified through comparison with available experimental and numerical data. The effects of foams' porosity, solid material, and Reynolds number on flow characteristics and heat transfer are investigated. Results are presented in terms of the permeability, Forchheimer coefficient, the volumetric and average heat transfer coefficient, and temperature and velocity distribution. By decreasing porosity, the flow complexity increases with subsequent increments in heat transfer and pressure drop. Also, the conductive heat transfer through the foam plays a vital role in the total heat transfer rate. These pore-scale outcomes could be used in macro-scale thermo-fluid models to perform more accurate simulations with less computational costs.

Online in-situ monitoring of melt pool characteristic based on a single high-speed camera in laser powder bed fusion process

• A coaxial melt pool temperature measurement system with a single high-speed camera in the LPBF process is developed. • A dual-waveband image-matching method with sub-pixel accuracy, and an overall parameter calibration and optimization method are proposed. • The melt pool characteristics including the temperature distribution, profile, temperature gradient, and cooling rate are measured by the developed system, and the distribution of average temperature and peak temperature under different linear energy densities during single-line printing is compared and analyzed. In metal additive manufacturing (AM), the in-situ measurement of the melt pool characteristic plays a significant role in monitoring the quality of the printed components. In this work, based on dual-wavelength thermometry, a coaxial melt pool temperature measurement system with a single high-speed camera in the laser powder bed fusion (LPBF) process is developed, including the design of the relay and optical path amplification system, and the beam splitting and chromatic aberration correction system. Moreover, a dual-waveband image-matching method with sub-pixel accuracy, and an overall parameter calibration and optimization method are proposed to improve the accuracy of the coaxial temperature measurement system. Besides, the validation experiment measured by a high-temperature blackbody furnace and a standard photoelectric pyrometer indicates that the temperature measuring error of the developed system is less than 1%. The melt pool characteristics including the temperature distribution, profile, temperature gradient, and cooling rate were measured by the developed coaxial temperature measurement system, and the distribution of average temperature and peak temperature under different linear energy densities during single-line printing was also compared and analyzed. The single-line printing results of different parameters show that the higher the linear energy density, the higher the average temperature and peak temperature of the melt pool, and the optimized parameters minimize the fluctuation of melt pool temperature and are more favorable to the formation of high-quality parts. In multi-layer printing mode, the heat accumulation is strong, resulting in the slow cooling rate of the melt pool.