scholarly journals Effect of Ambient Parameters on the Temperature Distribution of Photovoltaic (PV) Modules

Resources ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 107 ◽  
Author(s):  
Divine Atsu ◽  
Alok Dhaundiyal
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Transfer Coefficient ◽  
Thermal Conditions ◽  
Main Body ◽  
Pv System ◽  
Element Analysis ◽  
Pv Modules ◽  
The Heat Transfer Coefficient

This paper pivots around the influence of thermal parameters on the temperature distribution of a (PV) module. The solar irradiance, ambient temperature, and heat transfer coefficient were examined for four differently manufactured solar modules. A finite element analysis of the solar system was carried out to simulate the prevailing thermal conditions. It was determined through analysis that the heat transfer coefficient had a significant effect on the boundaries of the PV modules. The temperature gradient was relatively high at the boundary, whereas the main body had the least deviation from the mean value of experimental data. The high value of irradiance is favorable for a large PV system, while the heat transfer coefficient should be low for avoiding undulation of the thermal gradient across the plate. The temperature distribution on the surface of the PV modules largely depended on the geometry and the material used for the design purpose.

Using ProCAST to Study the Effects of SEED Process Parameters on the Radial Temperature Distribution in Semi-Solid Slugs

2020 ◽  
Vol 993 ◽  
pp. 1004-1010
Author(s):  
Min Luo ◽  
Da Quan Li ◽  
Wen Ying Qu ◽  
Stephen P. Midson ◽  
Qiang Zhu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Transfer Coefficient ◽  
Solid Fraction ◽  
Process Parameters ◽  
Radial Temperature ◽  
Fraction Distribution ◽  
Semi Solid ◽  
The Heat Transfer Coefficient

The SEED (Swirled Enthalpy Equilibrium Device) process was used to produce semi-solid slurries. One of the factors that controls whether or not a slug can be used to produce high quality castings is the solid fraction distribution within the slug, and the solid fraction distribution is strongly dependent upon the temperature distribution. In this study, a model has been developed using ProCAST to investigate the relationship between process parameters and the temperature distribution within slugs. The parameters examined included the heat transfer coefficient between the crucible and slug, the heat transfer coefficient between the crucible and air, the slug diameter, and the initial melt temperature (pouring temperature). It was found that the most important parameters controlling the temperature distribution within slugs were the crucible size and the heat transfer coefficient between crucible and air. Adjustment of other parameters had little influence on the temperature distribution. Processing parameters will be discussed in order to allow the SEED process to be used for the production of large diameter slugs (>100 mm), and for narrow freezing range (0.3<fs<0.5, fs is fraction solid) alloys such as 6063.

Research on the Inversion of Equivalent Surface Heat Transfer Coefficient of Mass Concrete by Calculating its Heat Flux

2012 ◽  
Vol 188 ◽  
pp. 264-269
Author(s):  
Li Xin Qu ◽  
Yi Hong Zhou ◽  
Yao Ying Huang ◽  
Guo Qing Tang ◽  
Shao Wu Zhou
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Optical Fiber ◽  
Transfer Coefficient ◽  
Surface Heat ◽  
Mass Concrete ◽  
Surface Heat Transfer Coefficient ◽  
The Heat Transfer Coefficient

Most of the cracks on concrete dam are external ones, while external heat preservation is an important measure to prevent cracking. In order to obtain the actual thermal parameters, according to thermal conduction theory and the temperature distribution conditions of optical fiber on concrete surface, the surface temperature distribution of concrete pouring deck was real-time monitored by setting optical fiber in different depths; then the surface heat flux of mass concrete was calculated, thereby the equivalent surface heat transfer coefficient, which varied as time goes, was inversed. It is indicated that the inversion process is relatively simple and reliable, and the heat transfer coefficient obtained can well reflect the real performance of the insulation materials. Meanwhile, it is also indicated that the heat transfer coefficient of equivalent surface varies as time goes, which can contribute to back analysis calculation and actual engineering practice.

scholarly journals Effect of Velocity and Temperature Distribution at the Hole Exit on Film Cooling of Turbine Blades

1997 ◽  
Vol 119 (2) ◽  
pp. 343-351 ◽  
Author(s):  
V. K. Garg ◽  
R. E. Gaugler
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Transfer Coefficient ◽  
Film Cooling ◽  
Turbine Blades ◽  
Suction Surface ◽  
Free Stream Turbulence ◽  
The Heat Transfer Coefficient ◽  
Coolant Velocity

An existing three-dimensional Navier–Stokes code (Arnone et al., 1991), modified to include film cooling considerations (Garg and Gaugler, 1994), has been used to study the effect of coolant velocity and temperature distribution at the hole exit on the heat transfer coefficient on three film-cooled turbine blades, namely, the C3X vane, the VKI rotor, and the ACE rotor. Results are also compared with the experimental data for all the blades. Moreover, Mayle’s transition criterion (1991), Forest’s model for augmentation of leading edge heat transfer due to free-stream turbulence (1977), and Crawford’s model for augmentation of eddy viscosity due to film cooling (Crawford et al., 1980) are used. Use of Mayle’s and Forest’s models is relevant only for the ACE rotor due to the absence of showerhead cooling on this rotor. It is found that, in some cases, the effect of distribution of coolant velocity and temperature at the hole exit can be as much as 60 percent on the heat transfer coefficient at the blade suction surface, and 50 percent at the pressure surface. Also, different effects are observed on the pressure and suction surface depending upon the blade as well as upon the hole shape, conical or cylindrical.

scholarly journals Study on the Thermal Properties of Hollow Shale Blocks as Self-Insulating Wall Materials

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Guo-liang Bai ◽  
Ning-jun Du ◽  
Ya-zhou Xu ◽  
Chao-gang Qin
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Thermal Properties ◽  
Transfer Coefficient ◽  
Wall Material ◽  
Element Analysis ◽  
Experimental Heat ◽  
Wall Materials ◽  
Save Energy ◽  
The Heat Transfer Coefficient

To reduce energy consumption and protect the environment, a type of hollow shale block with 29 rows of holes was designed and produced. This paper investigated the thermal properties of hollow shale blocks and walls. First, the guarding heat-box method was used to obtain the heat transfer coefficient of the hollow shale block walls. The experimental heat transfer coefficient is 0.726 W/m2·K, which would save energy compared to traditional wall materials. Then, the theoretical value of the heat transfer coefficient was calculated to be 0.546 W/m2·K. Furthermore, the one-dimensional steady heat conduction process for the block and walls was simulated using the finite element analysis software ANSYS. The predicted heat transfer coefficient for the walls was 0.671 W/m2·K, which was in good agreement with the test results. With the outstanding self-insulation properties, this type of hollow shale block could be used as a wall material without any additional insulation measures in masonry structures.

Effects of Averaging the Heat-Transfer Coefficient on the Predicted Material Temperature Distribution

2015 ◽  
Author(s):  
T. I-P. Shih ◽  
C.-S. Lee ◽  
K. M. Bryden
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Transfer Coefficient ◽  
Computational Study ◽  
Maximum Temperature ◽  
Bulk Temperature ◽  
Spanwise Direction ◽  
Gas Temperature ◽  
The Heat Transfer Coefficient

The heat-transfer coefficient (HTC) in internal-coolant passages can vary appreciably about a heat-transfer enhancement feature such as a pin fin, a rib, and a concavity because of stagnation regions and wakes about the enhancement feature. However, the computed or measured HTC is often averaged spatially in the spanwise direction or over some region when used in the design of cooling strategies. Since the variation in the HTC could be a factor of eight or more about an enhancement feature, it is of interest to understand the effects of averaging the HTC on the predicted temperature distribution in the solid subjected to the heating and cooling. In this computational study, a flat plate of thickness H (1 mm) and length L = 20H is heated on one side by either a constant heat flux (68 W/cm2) or a constant HTC (1,167.2 W/m2-K) and a constant hot-gas temperature (1,482 °C). On the cooled side, the free stream or bulk temperature is kept constant (400 °C) and the average HTC (1,442.5 W/m2-K) is kept constant as well. This average HTC on the cooled side is the average of a higher HTC (hH) and a lower HTC (hL). Two types of changes from hH to hL are considered — abrupt (or step) and gradual. When the HTC changes abruptly, hH is imposed over LH, and hL is imposed over LL=L–LH. When the HTC changes gradually from hH to hL, hH is imposed from from x = 0 to LH/2, and hL is imposed from x = 3LH/2 to L with a smooth variation in the HTC to connect hH and hL. Results obtained show that when the averaged HTC is used, the maximum temperature in the plate is 900 °C on the heated side of the plate. However, if the variation in the HTC is accounted for, then the maximum temperature in the plate could be as high as 1.363 times the maximum temperature predicted by assuming an averaged HTC. Also, for the range of parameters studied, the difference in the maximum and minimum temperature in the plate can increase by a factor of 16, which strongly affects thermal stress.

scholarly journals Enhancement of Temperature Distribution and Heat Transfer Coefficient of Ribbed Tube by Simulation

2021 ◽  
Vol 7 (1) ◽  
pp. 21-28
Author(s):  
Rahul Kunar ◽  
Dr Sukul Lomash
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Transfer Coefficient ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Flow Analysis ◽  
Total Heat ◽  
Total Heat Transfer ◽  
The Heat Transfer Coefficient

The heat transfer from surface may in general be enhanced by increasing the heat transfer coefficient between a surface and its surrounding or by increasing heat transfer area of the surface or by both. The main objective of the study and calculate the total heat transfer coefficient. Improve the heat transfer rate by using ANSYS CFD. During the CFD calculations of the flow in internally ribbed tubes. And calculated the temperature distribution and pressure inside the tube by using ansys. The model was created using CatiaV5 and meshed with Ansys, and the flow analysis is done with Ansys 19.2. The results showing that the heat transfer is increased. The enthalpy and temperature increase with flow is advancing when compare with normal boiler tube. In this study the total heat transfer rate of the pipe increase with the increase the rib height. Total heat transfer rate increase up to 7.7kw. The study show that the improvement in furnace heat transfer can be achieved by changing the internal rib design.

scholarly journals CFD simulations of heat transfer in internally helically ribbed tubes

2016 ◽  
Vol 37 (2) ◽  
pp. 251-260 ◽  
Author(s):  
Karol Majewski ◽  
Sławomir Grądziel
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Thermal Conditions ◽  
Water Layer ◽  
High Heat ◽  
High Heat Flux ◽  
Cfd Simulations ◽  
Power Boiler ◽  
The Heat Transfer Coefficient

Abstract Heating surfaces in power boilers are exposed to very high heat flux. For evaporator protection against overheating, internally helically ribbed tubes are used. The intensification of the heat transfer and the maintenance of the thin water layer in the intercostal space, using ribbed tubes, enables better protection of the power boiler evaporator than smooth pipes. Extended inner surface changes flow and thermal conditions by influencing the linear pressure drop and heat transfer coefficient. This paper presents equations that are used to determine the heat transfer coefficient. The results of total heat transfer, obtained from CFD simulations, for two types of internally ribbed and plain tubes are also presented.

scholarly journals Effect of Velocity and Temperature Distribution at the Hole Exit on Film Cooling of Turbine Blades

1995 ◽  
Author(s):  
Vijay K. Garg ◽  
Raymond E. Gaugler
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Transfer Coefficient ◽  
Film Cooling ◽  
Turbine Blades ◽  
Suction Surface ◽  
Free Stream Turbulence ◽  
The Heat Transfer Coefficient ◽  
Coolant Velocity

An existing three-dimensional Navier-Stokes code (Arnone et al., 1991), modified to include film cooling considerations (Garg and Gaugler, 1994), has been used to study the effect of coolant velocity and temperature distribution at the hole exit on the heat transfer coefficient on three film-cooled turbine blades, namely, the C3X vane, the VKI rotor, and the ACE rotor. Results are also compared with the experimental data for all the blades. Moreover, Mayle’s transition criterion (Mayle, 1991), Forest’s model for augmentation of leading edge heat transfer due to free-stream turbulence (Forest, 1977), and Crawford’s model for augmentation of eddy viscosity due to film cooling (Crawford et al., 1980) are used. Use of Mayle’s and Forest’s models is relevant only for the ACE rotor due to the absence of shower-head cooling on this rotor. It is found that, in some cases, the effect of distribution of coolant velocity and temperature at the hole exit can be as much as 60% on the heat transfer coefficient at the blade suction surface, and 50% at the pressure surface. Also, different effects are observed on the pressure and suction surface depending upon the blade as well as upon the hole shape, conical or cylindrical.

Simulation and Experimental Study of the Preheating Mould Temperature Distribution in Semi-Solid Diecasting

2021 ◽  
Vol 1035 ◽  
pp. 833-839
Author(s):  
Chao Gao ◽  
Min Luo ◽  
Da Quan Li ◽  
Song Chen ◽  
Jian Feng ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Transfer Coefficient ◽  
Temperature Difference ◽  
Great Influence ◽  
Experimental Result ◽  
Mould Temperature ◽  
Semi Solid ◽  
The Heat Transfer Coefficient

The mould temperature distribution has a great influence on the semi-solid diecasting. In the present study the temperature distribution of a plane-shaped mould was investigated by using the method of numerical simulation and experiment. The results showed that the preheating mould temperature field was affected by three important simulation parameters, the heat transfer coefficient hoil between the heat transfer oil and the mould, the heat transfer coefficient hair between the mould and the air, and the heat transfer coefficient hcontact between the mould core and the mould frame. The simulation results showed that (1) with the increase of hoil, the overall mould temperature imcreased; (2) with the increase of hair, the overall mould temperature decreased, while the surface temperature gradient of mould frame grad T-f and the temperature difference between the mould core and the mould frame ∆T increased; (3) With the increase of hcontact, ∆T decreased and the temperature of mould frame increased. When the heat oil temperature Toil=290°C, the heat transfer coefficients were optimized as hoil=500Wm-2K-1, hair=7Wm-2K-1, and hcontact=1000Wm-2K-1 according to the experimental results. The average temperature difference between the simulation result and the experimental result was 3.45°C, and the average relative error was 1.73%.

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