scholarly journals Performance enhancement of a baffle-type solar heat collector through CFD simulation study

2021 ◽  
Vol 1195 (1) ◽  
pp. 012040
Author(s):  
A S T Tan ◽  
J Janaun ◽  
H J Tham ◽  
N J Siambun ◽  
A Abdullah
Keyword(s):  
Pressure Drop ◽  
Solar Energy ◽  
Alternative Energy ◽  
Manufacturing Industry ◽  
Cfd Simulation ◽  
Performance Enhancement ◽  
Fluid Dynamic ◽  
Prolonged Heating ◽  
Solar Heat ◽  
Heat Collector

Abstract The application of solar energy conversion has been extensively utilized as an alternative energy source to generate heat. This approach would be a step towards sustainable energy development particularly in the manufacturing industry with energy-intensive process. In this paper, thermal enhancement on the key component of a solar energy device – solar heat collector (SHC), has been evaluated by proposing a baffle-type SHC with various geometric configuration in the air passage namely longitudinal baffle and transversal baffle. The performance of SHC is evaluated in term of efficiency, temperature distribution, airflow pattern and pressure drop across the collector outlet through Computational Fluid Dynamic (CFD) investigation. It was observed that maximum collector efficiency was achieved in the Longitudinal-SHC (L-SHC), with a value of 46.2 % followed by Transversal-SHC (T-SHC) and without baffles. Maximum drying temperature at the collector outlet was 332.43 K for L-SHC, showing temperature rise of 0.35 % and 4.21 % from T-SHC and without baffles, respectively. The velocity vector indicated that turbulence flow was created in the T-SHC which consequently improved the heat transfer. Whereas in L-SHC, enhancement was achieved through the prolonged heating time in the passage. Considering the thermo-hydraulic performance factor evaluated, these enhancement features had diminished the effect of pressure drop.

scholarly journals A Solar-Energy Method for Reducing Coffee-Drying Costs

1969 ◽  
Vol 47 (4) ◽  
pp. 226-235
Author(s):  
Allan L. Phillips
Keyword(s):  
Solar Energy ◽  
Static Pressure ◽  
Electric Heating ◽  
Operating Costs ◽  
Solar Heat ◽  
Processing Facility ◽  
Heat Collector ◽  
Electricity Costs ◽  
Labor Requirements ◽  
Experimental Processing

1. Modern coffee-processing facilities that have been developed recently have provided the features of low equipment costs and reduced labor requirements, but are somewhat expensive to operate when electric power is used entirely to heat the drying air. 2. The use of solar energy as a heat source was considered, since previous research where solar heat was used to dry other crops indicates that solar heat-collectors could also be used successfully for drying coffee. 3. An experimental processing facility which employs a solar heat-collector was built and operated, and it has been demonstrated that worthwhile reductions in operating costs can be achieved through the use of solar energy. 4. It was concluded that other coffee producers could economically use solar heat-collectors to reduce electricity costs. Drying facilities should be designed using the following as guides: A. Provide 10 square feet of drying-bin area for each 100 hundred-weights of coffee produced yearly. B. Install a fan which will deliver 100 c.f.m. per square foot of bin area against a static pressure of 1-inch water gage. C. Construct the solar heat-collector according to the specifications presented in figure 1. D. Install electric heating elements which provide up to 5,000 w. for each 100 hundred-weights processed yearly.

CFD Simulation of Hydrodynamics, Heat and Mass Transfer Simultaneously in Structured Packing

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
M.R. Khosravi Nikou ◽  
M.R. Ehsani ◽  
M. Davazdah Emami
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Pressure Drop ◽  
Heat And Mass Transfer ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Theoretical Plate ◽  
Absolute Relative Error ◽  
Gas Liquid Flow ◽  
Counter Current

This paper describes the results of computational fluid dynamic modeling of hydrodynamics, heat and mass transfer simultaneously in Flexipac 1Y operated under a counter-current gas-liquid flow condition. The simulation was performed for a binary mixture of methanol-isopropanol distillation. The pressure drop, the height of equivalent to theoretical plate (HETP) and temperature distribution across the column were calculated and compared with experimental data. The mean absolute relative error (MARE) between CFD predictions and experimental data for the pressure drop, HETP and temperature profile are 20.7%, 12.9% and 2.8%, respectively.

scholarly journals Impact of Forward Osmosis Operating Pressure on Deformation, Efficiency and Concentration Polarisation with Novel Links to CFD

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 161
Author(s):  
Alexander J. Charlton ◽  
Gaetan Blandin ◽  
Greg Leslie ◽  
Pierre Le-Clech
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Shear Strain ◽  
Cfd Simulation ◽  
Performance Enhancement ◽  
Membrane Surface ◽  
Forward Osmosis ◽  
Transmembrane Pressure ◽  
Operating Pressure ◽  
Concentration Polarisation

Forward osmosis (FO) modules currently suffer from performance efficiency limitations due to concentration polarisation (CP), as well as pressure drops during operation. There are incentives to further reduce CP effects, as well as optimise spacer design for pressure drop improvements and mechanical support. In this study, the effects of applying transmembrane pressure (TMP) on FO membrane deformation and the subsequent impact on module performance was investigated by comparing experimental data to 3D computational fluid dynamics (CFD) simulations for three commercial FO modules. At a TMP of 1.5 bar the occlusion of the draw-channel induced by longitudinal pressure hydraulic drop was comparable for the Toray (16%) and HTI modules (12%); however, the hydraulic perimeter of the Profiera module was reduced by 46%. CFD simulation of the occluded channels indicated that a change in hydraulic perimeter due to a 62% increase in shear strain resulted in a 31% increase in the Reynolds number. This reduction in channel dimensions enhanced osmotic efficiency by reducing CP via improved draw-channel hydrodynamics, which significantly disrupted the external concentration polarization (ECP) layer. Furthermore, simulations indicated that the Reynolds number experienced only modest increases with applied TMP and that shear strain at the membrane surface was found to be the most important factor when predicting flux performance enhancement, which varied between the different modules. This work suggests that a numerical approach to assess the effects of draw-spacers on pressure drop and CP can optimize and reduce investment in the design and validation of FO module designs.

CFD Simulation of Gas-Solid Flow in Dense Phase Bypass Pneumatic Conveying Using the Euler-Euler Model

2010 ◽  
Vol 26-28 ◽  
pp. 1190-1194 ◽  
Author(s):  
Y. Wang ◽  
K.C. Williams ◽  
M.G. Jones ◽  
B. Chen
Keyword(s):  
Pressure Drop ◽  
Simulation Model ◽  
Computational Fluid Dynamic ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Pneumatic Conveying ◽  
Dense Phase ◽  
Pipe Length ◽  
Initial Design ◽  
Euler Model

The pressure drop predictions across a bypass pipeline in dense phase pneumatic conveying were investigated numerically. The simulation was conducted using the commercial Computational Fluid Dynamic (CFD) software Fluent with the Euler- Euler model accounting for four-way coupling. Experiments and calculations were conducted using flyash powder conveyed in a horizontal pipeline. The influence of the pipe length on pressure drop prediction was also investigated. The results indicate that pressure prediction of the CFD simulation model for a bypass pipe is promising. The conclusion is that this investigation can offer improved insight and initial design modelling capability for bypass pneumatic conveying systems.

A Closed-Loop Temperature Control System for the Solar Energy Heat Collector

2012 ◽  
Vol 608-609 ◽  
pp. 22-26 ◽  
Author(s):  
Ming Yun Li ◽  
Yu Ning Zhong ◽  
Jia Bao Cheng
Keyword(s):  
Control System ◽  
Solar Energy ◽  
Temperature Control ◽  
Closed Loop ◽  
Temperature Stability ◽  
Fine Tuning ◽  
Temperature Control System ◽  
Inlet Temperature ◽  
Solar Heat ◽  
Heat Collector

According to GB /T 4271-2007 in regard to the temperature control requirements, we have designed a set of closed loop temperature control system, it uses two levels of temperature control, and it uses LabVIEW PID kit and an external controllable silicon module for secondary heating fine-tuning, the whole system ensures that the solar heat collector inlet temperature stability at the setting value ± 0.1 °C.

The Effect of Turbulence Promoters on Vacuum Membrane Distillation Module Performance

2020 ◽  
Author(s):  
Robert Krysko ◽  
Abdulaziz M. Alasiri ◽  
Umar Alqsair ◽  
Sertac Cosman ◽  
Alparslan Oztekin
Keyword(s):  
Pressure Drop ◽  
Concentration Polarization ◽  
Performance Enhancement ◽  
Fluid Dynamic ◽  
Membrane Distillation ◽  
Membrane Properties ◽  
Significant Finding ◽  
Dynamic Simulations ◽  
Baseline Design ◽  
Polarization Coefficient

Abstract Computational fluid dynamic simulations are conducted to compare the performance of three proposed VMD module designs. Key parameters, including concentration polarization coefficient (CPC), temperature polarization coefficient (TPC), mass flux, and module pressure drop, are evaluated to analyze flux performance and membrane wetting implications. The CFD simulations are conducted on a three-dimensional domain for each design with representative membrane properties. The Reynolds numbers evaluated are 500 and 1500. Contour plots are provided to gain insight into the flow-field characteristics. Stream-wise profiles and average values are provided as a means to compare the design performance. The results indicate that adding either net-type spacers or membrane corrugation to the feed channel provides performance enhancement over an empty channel design. It is found that both the net-type spacer concept and the corrugated membrane offer better flux performance over the baseline design (49%–60% for the net-type spacers and 62%–67% flux enhancement for the corrugated membrane), reduced concentration polarization coefficient (51% for the Re = 500 case and 45% for the Re = 1500 case for spacers and 58% for the Re = 500 case and 49% for the Re = 1500 case for corrugation), increased TPC (2%–3% higher), and increased wall shear stress over the baseline design. The most significant finding is that the corrugated membrane design accomplishes the listed performance improvement while yielding five times less pressure drop increase than the net-type spacer design.

scholarly journals Numerical Study of Viscous Fluid Flows in a Kenics Static Mixer

Mechanika ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 206-211
Author(s):  
Cherif BELHOUT ◽  
Mohamed BOUZIT ◽  
Brahim MENACER ◽  
Youcef KAMLA ◽  
Houari AMEUR
Keyword(s):  
Pressure Drop ◽  
Cfd Simulation ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Fluid Flows ◽  
Static Mixer ◽  
Static Mixers ◽  
Cosmetic Industry ◽  
Dynamic Software ◽  
Computational Fluid Dynamic Software

Since many years static mixers find usage in chemical, food, cosmetic and pharmaceutical industry. One of the most commonly used is the Kenics type static mixer. In a framework of the current work the CFD simulation for Kenics static mixer were performed. In food or cosmetic industry one must deal very often with non-Newtonian fluids. Therefore this work concerns the numerical study of non-Newtonian fluid flux in a kenics km static mixer with laminar flow using the Navier-Stocks equation governing the phenomenon and the pressure loss equation. This simulation was made using the computational fluid dynamic software (CFX 12.0). In this paper we studied the influence of the Reynolds number, the viscosity of the fluid, aspect ratio and the number of helical elements fixed on the pressure drop. It was found that the CFD results of pressure drop for non-Newtonian power law was similar to literature data (the correlation of C.D.GRACE 1971 and the numerical simulation of E.SAATDJIAN 2012).

Thermodynamic Analysis of Solar Heat Pump Assisted Heating Systems

2014 ◽  
Author(s):  
Zozan Siyahhan Türkgenç ◽  
Alican Çebi ◽  
Ali Celen ◽  
Ahmet Selim Dalkılıç ◽  
Somchai Wongwises
Keyword(s):  
Solar Energy ◽  
Heat Pump ◽  
Alternative Energy ◽  
Heating System ◽  
Heat Pumps ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Systems ◽  
Solar Heat ◽  
The City

In this study, a system has been developed which can be used for heating buildings by utilizing solar energy, which is free and abundant in our country, with the aim of minimizing fossil based fuel consumption especially at wintertime and this system’s efficiency has been analyzed mathematically with numerical methods. First of all, in this study the performance of a solar heat pump system is examined. The city of Antalya is chosen for this study which is in the southern region of Turkey with an abundant source of solar energy. The usability of solar energy throughout the year is examined and its application areas in building heating with the utilization of heat pumps are determined. In addition an auxiliary system with an alternative energy source is considered in case solar energy is insufficient by itself. In order to determine all of the above, energy analysis of the system is performed. The advantages of the solar heat pump heating system are studied considering the amount of energy saved and the efficiency of the system. Thermodynamic and thermoeconomic analysis has been carried out in order to determine how effectively the solar energy is utilized by the system and the advantages of solar heat pump.

Glass solar heat collector development

1975 ◽  
Author(s):  
R. GILLETTE ◽  
C. DEMINET ◽  
W. BEVERLY
Keyword(s):  
Solar Heat ◽  
Heat Collector

scholarly journals Impeller Optimization in Crossflow Hydraulic Turbines

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 313
Author(s):  
Marco Sinagra ◽  
Calogero Picone ◽  
Costanza Aricò ◽  
Antonio Pantano ◽  
Tullio Tucciarelli ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Structural Safety ◽  
3D Fem ◽  
Good Efficiency ◽  
Standard Material ◽  
Variable Head ◽  
Hydraulic Turbines ◽  
Constructive Simplicity ◽  
Mechanical Optimization

Crossflow turbines represent a valuable choice for energy recovery in aqueducts, due to their constructive simplicity and good efficiency under variable head jump conditions. Several experimental and numerical studies concerning the optimal design of crossflow hydraulic turbines have already been proposed, but all of them assume that structural safety is fully compatible with the sought after geometry. We show first, with reference to a specific study case, that the geometry of the most efficient impeller would lead shortly, using blades with a traditional circular profile made with standard material, to their mechanical failure. A methodology for fully coupled fluid dynamic and mechanical optimization of the blade cross-section is then proposed. The methodology assumes a linear variation of the curvature of the blade external surface, along with an iterative use of two-dimensional (2D) computational fluid dynamic (CFD) and 3D structural finite element method (FEM) simulations. The proposed methodology was applied to the design of a power recovery system (PRS) turbine already installed in an operating water transport network and was finally validated with a fully 3D CFD simulation coupled with a 3D FEM structural analysis of the entire impeller.

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