scholarly journals Performance assessment of triangular Obstacles mounted Solar Air Heater Using Taguchi Method

2021 ◽  
Author(s):  
Ashwni Ashwni ◽  
◽  
Sachin Gupta ◽  
Ramakant Rana ◽  
◽  
...  
Keyword(s):  
Heat Flux ◽  
Pressure Drop ◽  
Taguchi Method ◽  
Vertical Plane ◽  
Operating Conditions ◽  
Solar Air Heater ◽  
Performance Parameters ◽  
Taguchi Technique ◽  
Input Parameters ◽  
The Impact

In this experimental work, the investigation about the impact of the geometrical dispositions of the triangular obstacles on the performance parameters such as pressure drop and thermal efficiency. A number of input parameters affects the performance of the system. These input parameters are the heat flux, mass flow rate ( = 0.01 to 0.02 kg/s), obstacles’ height, h from 22 mm to 37.5 mm, their cross-stream wise pitch (Ly = 56 to 206 mm), their angle of inclination with the vertical plane (Θ = 300 - 900), and stream wise pitch (Lx =30 to 70 mm). Moreover, an optimum set of input parameters is determined using the statistical modeling of the operating conditions by the Taguchi technique.

scholarly journals Pipeline Design Software and the Simulation of Liquid Propane/Butane - Light Oils Pipeline Operations

1996 ◽  
Author(s):  
John Peters
Keyword(s):  
Pressure Drop ◽  
Computer Software ◽  
Simulation Software ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Fluid Temperature ◽  
Fluid Properties ◽  
Products Pipeline ◽  
The Impact ◽  
Propane Butane

A comprehensive and integrated suite of computer software routines has been developed to simulate the flow of liquids in pipelines. The fluid properties module accommodates Newtonian and non-Newtonian liquids or mixtures including corrections for changes in properties with temperature and pressure. The hydraulic model calculates pressure drop in single or looped pipelines based on the diameter, route (length) and profile data provided. For multi-product pipelines the hydraulics module estimates energy loss for any sequence of batches given the size and fluid properties of each batch, and the velocity in the pipeline. When the characteristics of existing or proposed pipeline pumps are included, location and size of pumps can be optimized. The effect of heat loss on pressure drop is predicted by invoking the module which calculates the fluid temperature profile based on operating conditions, fluid properties, pipe and insulation conductivity and soil heat transfer data. Modules, created to simulate heater or cooler operations, can be incorporated to compensate for changes in temperature. Input data and calculated results can be presented in a format customized by the user. The simulation software has been successfully applied to multi-product, fuel oil, and non-Newtonian emulsion pipelines. The simulation and operation of a refinery products pipeline for the transportation of propane, butane, gasoline, jet and diesel batches will be discussed. The impact of high vapour pressure batches (i.e., propane and butane) on the operation of the pipeline and on the upstream and downstream facilities will be examined in detail.

scholarly journals Thermal Resistance and Pressure Drop Minimization for a Micro-gap Heat Sink with Internal Micro-fins by Parametric Optimization of Operating Conditions

CFD Letters ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 100-112
Author(s):  
Shugata Ahmed ◽  
Erwin Sulaeman ◽  
Ahmad Faris Ismail ◽  
Muhammad Hasibul Hasan ◽  
Zahir Hanouf
Keyword(s):  
Heat Flux ◽  
Pressure Drop ◽  
Thermal Resistance ◽  
Void Fraction ◽  
Heat Sink ◽  
Operating Conditions ◽  
Superior Performance ◽  
Pumping Power ◽  
Two Phase ◽  
Total Thermal Resistance

In recent years, researchers are investigating several potential applications of two-phase flow in micro-gap heat sinks; electronic cooling is one of them. Further, internal micro-fins are used to enhance the heat transfer rate. However, the pressure drop penalty due to small gap height and fin surfaces is a major concern. Hence, minimization of thermal resistance and pressure drop is required. In this paper, effects of operating conditions, e.g., wall heat flux, pumping power, and inlet void fraction, on total thermal resistance and pressure drop in a micro-gap heat sink with internal micro-fins of rectangular and triangular profiles have been investigated by numerical analysis for the R-134a coolant. Furthermore, optimization of these parameters has been carried out by response surface methodology. Simulation results show that rectangular micro-fins show superior performance compared to triangular fins in reducing thermal resistance. Finally, for an optimum condition (7.1202×10-5 W pumping power, 1.2×107 Wm-2 heat flux, and 0.03 inlet void fraction), thermal resistance and pressure drop are reduced by 56.3% and 87.2%, respectively.

On Identifying Condenser Design Deficiencies

2006 ◽  
Author(s):  
Joseph W. Harpster
Keyword(s):  
Operating Conditions ◽  
Performance Parameters ◽  
Performance Loss ◽  
Noncondensable Gas ◽  
Gross Error ◽  
Comprehensive Knowledge ◽  
Research Findings ◽  
Mixture Dynamics ◽  
Design Deficiencies ◽  
The Impact

How well a condenser is performing is shown to be difficult to determine. The result obtained by using defined measurements in this determination is sometimes biased by shell side conditions that are often not well understood, leading to gross error in calculated condenser performance parameters. This paper describes some of these conditions, identified through recent research findings, and introduces methods to minimize the extent of the error. The discussion addresses how these condenser operating conditions have impact on calculated condenser performance parameters and how they may be properly understood by making use of relatively new measurements or through the application of comprehensive knowledge of the water vapor and noncondensable gas mixture dynamics. Such conditions as measured air in-leakage, and knowledge of no or very low tube fouling based on recent cleaning, are important for the purpose of quantifying the impact of design deficiencies on calculated condenser performance parameters. With proper condenser monitoring, telltale indicators of these deficiencies are clearly observed and will be presented. An investigation program that identifies the amount of performance loss, and the recoverable portion through condenser modifications, is discussed.

Novel Unsteady Temperature/Heat Transfer Instrumentation and Measurements in the Presence of Combustor Instabilities

2005 ◽  
Author(s):  
K. S. Chana ◽  
K. J. Syed ◽  
M. I. Wedlock ◽  
R. W. Copplestone ◽  
M. S. Cook ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Gas Turbine ◽  
Temperature Fluctuations ◽  
Operating Conditions ◽  
Main Reaction ◽  
Wall Heat Transfer ◽  
Unsteady Temperature ◽  
Pressure Dynamics ◽  
The Impact

Lower NOx emissions from gas turbine combustion systems can be achieved through reducing the equivalence ratio of the main reaction zone and/or increasing the burner pressure drop. This strategy however takes pressure drop and/or air away from the combustor cooling, thereby compromising the combustor life. In order to achieve an optimum design that is a good compromise between low emissions and long component life, accurate heat transfer prediction is essential. It is well known that free stream turbulence can influence wall heat transfer characteristics. However the impact of combustion induced pressure dynamics, and the associated unsteady fluid dynamics, upon combustor wall heat transfer has not been adequately investigated. This paper reports on combustion tests conducted at gas turbine operating conditions, where pressure dynamics have been controlled by altering combustor operating conditions and through the use of a siren placed in the upstream air flow. Combustor wall temperatures were measured using standard thermocouples and QinetiQ’s “True Surface Thermocouples” (TST). The latter, which were mounted on the hot gas surface of the wall, are capable of a fast response and are capable of indicating the temperature fluctuations experienced by the metal surface. Fourier analysis of the TSTs showed no particular peaks associated with the pressure dynamics. This suggests that any coherence is damped within the boundary layer or by the thermal inertia of the metal. However temperature fluctuations of up to about 100°C were detected.

scholarly journals Optimization of Production Parameters in Oriented Strand Board (OSB) Manufacturing by Using Taguchi Method

2021 ◽  
Vol 72 (4) ◽  
pp. 347-352
Author(s):  
Ahad Furugi ◽  
Fatih Yapici
Keyword(s):  
Taguchi Method ◽  
Oriented Strand Board ◽  
Orthogonal Design ◽  
Process Conditions ◽  
Taguchi Technique ◽  
Effective Parameters ◽  
Pressure Time ◽  
Verification Test ◽  
The Impact

Optimization of process conditions in oriented strand board (OSB) manufacturing is a very important issue for both reducing cost and improving the quality of panels. Taguchi experimental design technique was applied to determination and optimization of the most influential controlling parameters of OSB panels such as press condition (pressure-time-temperature) and the ratio of adhesive parameters on modulus of elasticity (MOE). The value of the MOE is one of the very important mechanical properties of OSB panels. For this purpose, several experiments were conducted according to Taguchi L27 orthogonal design. The signal-to-noise (S/N) and the analysis of variance (ANOVA) were used to find the optimum levels and to indicate the impact of the controlling parameters on MOE. A verification test was also performed to prove the effectiveness of Taguchi technique. Since the predicted and the measured values were very close to each other, it was concluded that the Taguchi method was very successful in the optimization of effective parameters in OSB’s manufacturing.

scholarly journals Investigation of R134a Flow Boiling Heat Transfer and Pressure Drop in the Evaporator Test Section of Refrigeration System

2018 ◽  
Vol 25 (1) ◽  
pp. 13-31
Author(s):  
Ahmed J. Hamad ◽  
Zahraa Kareem Yasser
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Flow Boiling ◽  
Saturation Temperature ◽  
Operating Conditions ◽  
Refrigeration System ◽  
Test Conditions

This paper presents an experimental and theoretical analysis to investigate the two-phase flow boiling heat transfer coefficient and pressure drop of the refrigerant R-134a in the evaporator test section of the refrigeration system under different operating conditions. The test conditions considered are, for heat flux (13.7-36.6) kW/m2, mass flux (52-105) kg/m2.s, vapor quality (0.2-1) and saturation temperature (-15 to -3.7) ˚C. Experiments were carried out using a test rig for a 310W capacity refrigeration system, which is designed and constructed in the current work. Investigating of the experimental results has revealed that, the enhancement in local heat transfer coefficient for relatively higher heat flux 36.6 kW/m2 was about 38% compared to 13.7 kW/m2 at constant operating conditions. The enhancement in heat transfer coefficient was about 57% when the mass flux increased from 52 kg/m2.s to 105 kg/m2.s at constant test conditions. The enhancement in the heat transfer coefficient was about 64% when the saturation temperature increased from -8 to -3.7 at fixed refrigerant mass velocity and heat flux. The effect of mass velocity on pressure drop was relatively higher by about 27% than that for heat flux at specified test conditions. The comparison between the experimental and theoretical results has shown an acceptable agreement with an average deviation of 21%.  

Comparison of Photovoltaic Module Performance Measurements

Solar Energy ◽  
2005 ◽  
Author(s):  
A. Hunter Fanney ◽  
Mark W. Davis ◽  
Brian P. Dougherty ◽  
David L. King ◽  
William E. Boyson ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Simulation Model ◽  
Energy Production ◽  
Performance Parameters ◽  
Performance Measurements ◽  
Air Mass ◽  
Photovoltaic Modules ◽  
Input Parameters ◽  
Module Performance ◽  
The Impact

Computer simulation tools used to predict the energy production of photovoltaic systems are needed in order to make informed economic decisions. These tools require input parameters that characterize module performance under various operational and environmental conditions. Depending upon the complexity of the simulation model, the required input parameters can vary from the limited information found on labels affixed to photovoltaic modules to an extensive set of parameters. The required input parameters are normally obtained indoors using a solar simulator or flash tester, or measured outdoors under natural sunlight. This paper compares measured performance parameters for three photovoltaic modules tested outdoors at the National Institute of Standards and Technology (NIST) and Sandia National Laboratories (SNL). Two of the three modules were custom fabricated using monocrystalline and silicon film cells. The third, a commercially available module, utilized triple-junction amorphous silicon cells. The resulting data allow a comparison to be made between performance parameters measured at two laboratories with differing geographical locations and apparatus. This paper describes the apparatus used to collect the experimental data, test procedures utilized, and resulting performance parameters for each of the three modules. Using a computer simulation model, the impact that differences in measured parameters have on predicted energy production is quantified. Data presented for each module include power output at standard rating conditions and the influence of incident angle, air mass, and module temperature on each module’s electrical performance. Measurements from the two laboratories are in excellent agreement. The power at standard rating conditions is within 1% for all three modules. Although the magnitude of the individual temperature coefficients varied as much as 17% between the two laboratories, the impact on predicted performance at various temperature levels was minimal, less than 2%. The influence of air mass on the performance of the three modules measured at the laboratories was in excellent agreement. The largest difference in measured results between the two laboratories was noted in the response of the modules to incident angles that exceed 75°.

Experimental Investigation of Pressure Drop of Flow Boiling at Vertical Narrow Rectangular Channel

2008 ◽  
Author(s):  
Liang-Ming Pan ◽  
De-Qi Chen ◽  
De-Wen Yuan
Keyword(s):  
Heat Flux ◽  
Pressure Drop ◽  
Flow Boiling ◽  
Rectangular Channel ◽  
Vertical Channel ◽  
Narrow Channel ◽  
Operating Conditions ◽  
Experimental Results ◽  
Two Phase ◽  
Modified Model

Narrow channel heat transfer element has been extensive adopted in engineering applications, especially at electronics technology, this kind of elements often be used to construct compact heat exchanger. Pressure drop of flow boiling at vertical channel with gaps of 1.7, 2.2 and 3.6 mm was experimentally investigated in this paper. The variation of the two-phase frictional multiplier vs. heat flux at various operating conditions was gotten experimentally, possible mechanism of the two-phase frictional multiplier trends of narrow channel were analyzed. Experimental results revealed that the two-phase frictional multiplier increased at lower flow rate and heat flux, as well as higher vapor quality, and dropped at wider flow gap. The multiplier can not be estimated by commonly used method for ordinary gap, thus a modified model of pressure drop for narrow channel was proposed considering the size effects of channel. The error of the predicted two-phase frictional multiplier is within ±15.4% compared with experimental results.

On Experimental and Computational Investigation of Heat Transfer Deterioration and Hydraulic Resistance in Annular Channel and SCWR 3-Rod Bundle

2018 ◽  
Author(s):  
Vladislav V. Filonov ◽  
Yuliia S. Filonova ◽  
Victor G. Razumovskiy ◽  
Evgeniy N. Pis'mennyi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Pressure Drop ◽  
Thermal State ◽  
Annular Channel ◽  
Operating Conditions ◽  
Mass Rate ◽  
Heat Transfer Deterioration ◽  
Annular Channels ◽  
Vertical Annuli

The experiments on upward flow of supercritical water in a vertical annuli and 3-rod tight bundle simulator made of 485-mm heated-length tubes of 5.2-mm OD and 4.5-mm ID with four helical ribs of 0.6-mm height, 1-mm width, and axial 400-mm pitch are presented. Heat transfer and pressure drop under various operating conditions (inlet pressure and temperature, flow mass rate and heat flux) were investigated. Longitudinal wall temperature profiles made it possible to determine the place and flow thermal state of heat transfer deterioration (HTD) onset. Analysis of the obtained data (about 200 regimes) proved their good enough agreement with the correlations previously derived by the authors both for the heat flux rate (q/G)b of HTD beginning and for pressure drop in round tubes and annular channels. These correlations were updated to correct the results of their prediction. Computational fluid dynamics and its counterpart computational heat transfer were used for modeling the above-mentioned thermohydraulic processes studied in the first part of the work by finding the most adequate flow turbulence model and optimized domain meshing. The accepted model was benchmarked by some data on heat transfer and pressure drop in tubes and annular channels cooled by SCW.

Novel Arrangement of Rough Tubes for Heat Flux Improvement

2012 ◽  
Vol 326-328 ◽  
pp. 81-86
Author(s):  
Farshad Farahbod ◽  
Sara Farahmand ◽  
Farzaneh Farahbod
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Crude Oil ◽  
Transfer Coefficient ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Set Up ◽  
The Heat Transfer Coefficient

The objective of the research is to represent a novel arrangement of conical three dimensional rough tubes (FS3D) for heat transfer coefficient enhancement. Experiments were performed with 316 stainless steel tubes of FS3D roughness and hot crude oil was circulated in constant heat flux condition in the related set up. The pressure drop is measured in this set up and compared with the pressure drop in a smooth tube with the same operating conditions. The heat transfer coefficient is one of essential parameters for design of heat transfer equipments and in this experimental work this is investigated for an Iranian crude oil in the FS3D rough tube. The heat transfer coefficient in FS3D rough tubes is higher than in other commercial enhanced tubes. FS3D rough tubes improve the performance of heat transfer equipments and also optimize the size of the mentioned devices. Consequently this type, the FS3D rough tube, is advantageous in energy and cost saving.

Sign in / Sign up

Export Citation Format

Share Document