Second Law Analysis Optimal Design of a Mixer for Sanitary Water

2014 ◽  
Author(s):  
Adriano Sciacovelli ◽  
Vittorio Verda ◽  
Stefano Mauro
Keyword(s):  
Optimal Design ◽  
Entropy Generation ◽  
Cold Water ◽  
Hot Water ◽  
Pressure Losses ◽  
Thermal Mixing ◽  
Average Temperature ◽  
Design Variables ◽  
Commercial Code ◽  
Energy Equations

In this work, entropy generation analysis is used in the search for the optimal design of a mixer for sanitary water. An innovative design of the device is considered: hot water and cold water enter a manifold from five orifices, which opening is controlled by actuators, depending on the requested mass flow rate and average temperature. The design variables are the position of the various orifices, which are modified in order to minimize the mixing length and response time of the device, as well as the global pressure losses. Analysis is conducted using a thermofluid dynamic model which includes continuity, momentum and energy equations, that are solved using a commercial code. Results are then used to calculate the entropy generation distribution, in order to properly consider the various sources of irreversibilities, some of which are necessary (thermal mixing) and some undesired (pressure losses).

scholarly journals Design of a vertical annulus with MHD flow using entropy generation analysis

2013 ◽  
Vol 17 (4) ◽  
pp. 1013-1022 ◽  
Author(s):  
Omid Mahian ◽  
Hakan Oztop ◽  
Ioan Pop ◽  
Shohel Mahmud ◽  
Somchai Wongwises
Keyword(s):  
Heat Exchanger ◽  
Optimal Design ◽  
Entropy Generation ◽  
Energy Cost ◽  
Mhd Flow ◽  
Constant Heat Flux ◽  
Convection Flow ◽  
Vertical Annulus ◽  
Flow Effects ◽  
Energy Equations

Optimal design of a heat exchanger is one of the concerns of energy conversion engineers. In the present work, the mixed convection flow between two vertical concentric pipes with constant heat flux at the boundaries and MHD flow effects is considered. To determine the optimal design for such a heat exchanger, at first, the momentum and energy equations are simplified and solved analytically. Next, using entropy generation analysis and cost analysis, the operational costs due to entropy generation are estimated. It is concluded that with an increase in the Hartmann number, the energy costs increase. In addition, for two small deviations from the base radius ratio )2(=P including 9.1=P and 1.2=P , the changes in the energy cost are calculated. It is found that for 9.1=P the energy cost increases by 17.5% while for P = 2.1 the energy cost is reduced by 13.6 %.

Experimental Investigation of Heat Transfer Enhancement by Using Different Number of Fins in Circular Tube

2018 ◽  
Vol 6 (3) ◽  
pp. 1-12
Author(s):  
Kamil Abdul Hussien
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Cold Water ◽  
Finned Tube ◽  
Hot Water ◽  
Copper Tube ◽  
Smooth Tube ◽  
Tube Heat Exchanger ◽  
Mass Flow Rates ◽  
Flow Heat

Abstract-The present work investigates the enhancement of heat transfer by using different number of circular fins (8, 10, 12, 16, and 20) in double tube counter flow heat exchanger experimentally. The fins are made of copper with dimensions 66 mm OD, 22 mm ID and 1 mm thickness. Each fin has three of 14 mm diameter perforations located at 120o from each to another. The fins are fixed on a straight smooth copper tube of 1 m length, 19.9 mm ID and 22.2 mm OD. The tube is inserted inside the insulated PVC tube of 100 mm ID. The cold water is pumped around the finned copper tube, inside the PVC, at mass flow rates range (0.01019 - 0.0219) kg/s. The Reynold's number of hot water ranges (640 - 1921). The experiment results are obtained using six double tube heat exchanger (1 smooth tube and the other 5 are finned one). The results, illustrated that the heat transfer coefficient proportionally with the number of fin. The results also showed that the enhancement ratio of heat transfer for finned tube is higher than for smooth tube with (9.2, 10.2, 11.1, 12.1 13.1) times for number of fins (8, 10, 12, 16 and 20) respectively.

Structural Analysis and Optimal Design of Lightweight Skate for Loading and Unloading

2013 ◽  
Vol 785-786 ◽  
pp. 1258-1261
Author(s):  
In Pyo Cha ◽  
Hee Jae Shin ◽  
Neung Gu Lee ◽  
Lee Ku Kwac ◽  
Hong Gun Kim
Keyword(s):  
Topology Optimization ◽  
Structural Analysis ◽  
Optimal Design ◽  
Optimization Techniques ◽  
Normal Operation ◽  
Stress And Strain ◽  
Initial Model ◽  
Design Variables ◽  
Model Set ◽  
Main Frame

Topology optimization and shape optimization of structural optimization techniques are applied to transport skate the lightweight. Skate properties by varying the design variables and minimize the maximum stress and strain in the normal operation, while reducing the volume of the objective function of optimal design and Skate the static strength of the constraints that should not degrade compared to the performance of the initial model. The skates were used in this study consists of the main frame, sub frame, roll, pin main frame only structural analysis and optimal design was performed using the finite element method. Simplified initial model set design area and it compared to SM45C, AA7075, CFRP, GFRP was using the topology optimization. Strength does not degrade compared to the initial model, decreased volume while minimizing the stress and strain results, the optimum design was achieved efficient lightweight.

scholarly journals Modeling, Simulation and Uncertain Optimization of the Gun Engraving System

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 398
Author(s):  
Tong Xin ◽  
Guolai Yang ◽  
Fengjie Xu ◽  
Quanzhao Sun ◽  
Alexandi Minak
Keyword(s):  
Performance Evaluation ◽  
Optimal Design ◽  
Resistance Force ◽  
Gas Temperature ◽  
Evaluation Indexes ◽  
Uncertain Optimization ◽  
Design Variables ◽  
Set Up ◽  
Rotating Band ◽  
Percent Decrease

The system designed to accomplish the engraving process of a rotating band projectile is called the gun engraving system. To obtain higher performance, the optimal design of the size parameters of the gun engraving system was carried out. First, a fluid–solid coupling computational model of the gun engraving system was built and validated by the gun launch experiment. Subsequently, three mathematic variable values, like performance evaluation indexes, were obtained. Second, a sensitivity analysis was performed, and four high-influence size parameters were selected as design variables. Finally, an optimization model based on the affine arithmetic was set up and solved, and then the optimized intervals of performance evaluation indexes were obtained. After the optimal design, the percent decrease of the maximum engraving resistance force ranged from 6.34% to 18.24%; the percent decrease of the maximum propellant gas temperature ranged from 1.91% to 7.45%; the percent increase of minimum pressure wave of the propellant gas ranged from 0.12% to 0.36%.

scholarly journals The Effect of Thermo-Mechanical Processing on Physical Properties of Processed Amaranth and Oat Bran Composites

2017 ◽  
Vol 6 (2) ◽  
pp. 82
Author(s):  
Sean X. Liu ◽  
Diejun Chen ◽  
George E. Inglett ◽  
Jingyuan Xu
Keyword(s):  
Physical Properties ◽  
High Speed ◽  
Functional Foods ◽  
Cold Water ◽  
Essential Amino Acids ◽  
Hot Water ◽  
Blood Cholesterol ◽  
Gluten Free ◽  
Oat Bran ◽  
Amaranth Flour

Amaranth-oat composites were developed using gluten free amaranth flour containing essential amino acids and minerals with oat products containing β-glucan, known for lowering blood cholesterol. Amaranth flour and oat bran concentrate (OBC) composites (1:4) were processed using different technologies, including dry mixing, baking, steaming, cold wet blending, and high speed homogenizing (Polytron PT6000) with cold water or hot water. The results showed that water holding capacities, pasting, and rheological properties were dramatically increased by wet blending, Polytron with cold water, and Polytron with hot water followed by drum drying. The processing procedures created dissimilar physical properties that will enhance the application of ancient grains and oat for functional foods that are suitable for people who are gluten-intolerant. In addition, the dietary fiber contents of composites were increased by the incorporation of OBC. The composites can be inexpensively prepared and processed. The new healthful products will be affordable for people who suffer from celiac disease or gluten-intolerant. These innovative gluten-free functional food products will help millions of gluten sensitive consumers enjoy heart-healthy functional foods.

Experimental and Numerical Study of Mixing in a Hot-Water Storage Tank

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
A. Aviv ◽  
Y. Blyakhman ◽  
O. Beeri ◽  
G. Ziskind ◽  
R. Letan
Keyword(s):  
Numerical Model ◽  
Storage Tank ◽  
Numerical Study ◽  
Tap Water ◽  
Three Dimensional ◽  
Hot Water ◽  
Software Validation ◽  
Water Storage Tank ◽  
Thermal Mixing ◽  
Numerical Investigations

Thermal mixing and stratification are explored numerically and experimentally in a cylindrical tank, which simulates a storage of water heated by a solar collector. The tank is 70cm in height and 24cm in diameter. The inlet and outlet are vertical and located off the centerline of the tank. The study is conducted in a transient mode, namely, the tank is filled with hot water, and as the hot water is being withdrawn, the tap water replaces it in a stratified way or by mixing. The flowrates of 2l∕min, 3l∕min, 5l∕min and 7l∕min, which correspond to superficial velocities of 4.35cm∕min, 6.52cm∕min, 10.87cm∕min, and 15.2cm∕min, are explored. Temperature of hot water ranges within 40–50°C, while the tap water is about 25–27°C. Installation of one and two horizontal baffles above the inlet is examined. Simultaneous experimental and numerical investigations are performed. In the experiment, both flow visualization and temperature measurements are used. Three-dimensional transient numerical simulations are done using the FLUENT 6 software. Validation of the numerical model is achieved by comparison with the experimental results. Then, the numerical model is applied to a study of various possible changes in the system. The results show that at low flowrates, up to a superficial velocity of about 11cm∕min through the tank, the baffles have no effect on tap water mixing with the stored hot water. At higher flowrates, a single horizontal baffle prevents the mixing and preserves the desired stratified temperature distribution in the storage tank.

scholarly journals Thermal Characteristics Analysis on Multi- Heat Pipe Induced Heat Exchanger

2019 ◽  
Vol 9 (2S2) ◽  
pp. 143-147 ◽  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Pipe ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Cold Water ◽  
Hot Water ◽  
Working Fluid ◽  
Physical Parameters

In this investigation of multi heat pipe induced in heat exchanger shows the developments in heat transfer is to improve the efficiency of heat exchangers. Water is used as a heat transfer fluid and acetone is used as a working fluid. Rotameter is set to measure the flow rate of cold water and hot water. To maintain the parameter as experimental setup. Then set the mass flow rate of hot water as 40 LPH, 60LPH, 80 LPH, 100LPH, 120 LPH and mass flow rate of cold water as 20 LPH, 30 LPH, 40 LPH, 50 LPH, and 60 LPH. Then 40 C, 45 ºC, 50 ºC, 55 C, 60 ºC are the temperatures of hot water at inlet are maintained. To find some various physical parameters of Qc , hc , Re ,, Pr , Rth. The maximum effectiveness of the investigation obtained from condition of Thi 60 C, Tci 32 C and 100 LPH mhi, 60 LPH mci the maximum effectiveness attained as 57.25. Then the mhi as 100 LPH, mci as 60 LPH and Thi at 40 C as 37.6%. It shows the effectiveness get increased about 34.3 to the maximum conditions.

scholarly journals Simulation of the effectiveness of longitudinal rectangular fins on the efficiency of the double pipe heat exchanger

2019 ◽  
Vol 21 (4) ◽  
pp. 48-57
Author(s):  
N. F. Timerbaev ◽  
A. K. Ali ◽  
Omar Abdulhadi Mustafa Almohamed ◽  
A. R. Koryakin
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cold Water ◽  
Tube Diameter ◽  
Hot Water ◽  
Outer Tube ◽  
Design Parameters ◽  
Double Pipe ◽  
Central Pipe ◽  
Pipe Heat

In this article, a mathematical simulation of a double pipe heat exchanger is carried out, having the longitudinal rectangular fins with the dimension of (2*3*1000) mm, mounted on the outer surface of the inner tube of the heat exchanger. In this paper, the advantage of using of that type of fins and its effect on the effectiveness of the heat exchanger are studied with the help of the computer program. The carried out research allowsmaking the calculation to find the optimum design parameters of heat exchangers. The outer tube diameter is (34.1mm) while the inner tube diameter is (16.05mm). The tubes wall thickness is (1.5mm) and the model length was (1 m). The hot water is flowing through the inner tube in parallel with the cold water that passing the outer tube. The hot and cold water temperature at the inlet is (75°C & 30°C) respectively. The mass flow rate inside the central pipe is (0.1 kg/s) while the annular pipe carrying (0.3 kg/s). In the present work, the program ANSYS Workbench 15.0 was used to find out the results of heat transfer as well as the behavior of liquids inside the heat exchangers.

scholarly journals Antibacterial activity of ginger extracts and its essential oil on some of pathogenic bacteria

2010 ◽  
Vol 7 (3) ◽  
pp. 1159-1165
Author(s):  
Baghdad Science Journal
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Pathogenic Bacteria ◽  
Cold Water ◽  
Water Extract ◽  
Ethanolic Extract ◽  
Hot Water ◽  
Diffusion Method ◽  
Resistant Bacteria

The antimicrobial activity of ginger extracts ( cold-water, hot-water, ethanolic and essential oil ) against some of pathogenic bacteria ( Escherichia coli , Salmonella sp , Klebsiella sp , Serratia marcescens, Vibrio cholerae , Staphylococcus aureus , Streptococcus sp) was investigated using Disc diffusion method , and the results were compared with the antimicrobial activity of 12 antibiotics on the same bacteria . The results showed that the ginger extracts were more effective on gram-positive bacteria than gram-negative . V. cholerae and S. marcescens,were the most resistant bacteria to the extracts used , while highest inhibition was noticed against Streptococcus sp (28 mm) . The ethanolic extract showed the broadest antibacterial activity ( 11 to 28 mm ) , in comparison with moderate activity of essential oil , it was observed that the cold-water extract was more effective on the bacteria than hot-water extract . Ginger ethanolic extract presented higher diameter of inhibition zone for Streptococcus sp than in Ciprofloxacin , Cefotaxime , Cefalotin , Cephalexin and Cephaloridine , also it was found a similarity between the higher inhibition zones of ethanolic extract of ginger and some antibiotics for S. aureus , E. coli , Salmonella sp and Klebsiella sp . V. cholerae and S. marcescens,also highly resistant to antibiotics . Phytochemical analysis of ethanolic extract of ginger revealed the present of glycosides, terpenoids, flavonids and phenolic compounds

scholarly journals Potassium Recovery Potential of Selected Agroforestry and Organic Wastes in Ibadan, Nigeria

2017 ◽  
Vol 13 (6) ◽  
pp. 492
Author(s):  
Akindejoye F. ◽  
Hammed T.B. ◽  
Sridhar M.K.C.
Keyword(s):  
Cold Water ◽  
Organic Wastes ◽  
Hot Water ◽  
Water Extraction ◽  
Recovery Potential ◽  
Sodium Magnesium ◽  
Cheap Alternative ◽  
K Concentration ◽  
Coconut Fibre ◽  
Mineral Concentrations

This study explored potassium recovery from agroforestry wastes that may be a cheap alternative to imported ones. The wastes: Plantain Peel (PP), Coconut Fibre (CF), Coconut Shell (CS), Cocoa Pod (CP), Sugarcane Bagasse (SB), Sawdust (SD) and four common wood-fuel species - Antiaris toxicaria (Wd1), Cordia millenii (Wd2), Khayas senegalensis (Wd3) and Milicia excelsa (Wd4) were assessed for their ash content (AC) and moisture content (MC), using standard procedures of AOAC. Atomic Absorption spectrophotometer was used to determine mineral concentrations: potassium, sodium, magnesium, calcium, zinc, lead and iron of the wastes. In addition, efficacy of three methods of extracting potassium from ashes: cold water extraction at 35 OC, hot water extraction at 90 OC and steam extraction was assessed. Data were analysed using descriptive statistics and correlation test at p˂0.05. Wastes with highest values in terms of AC and MC were: CP (AC- 11.62 ± 0.3 %) and SB (MC- 82 ± 2.64 %). The highest concentration of K (mg·kg -1 ) was found in CP (8,387.50 ± 2.00 mg·kg-1 ). Cold water extraction gave the most potassium yield (88.44 %) and the highest solid potash content was found in PP (68 500 mg·kg -1 ) while CP had the highest K concentration (12.51±0.20 g·dm-3 ). Cocoa pod, plantain peel and Cordia millenii are very good sources of agroforestry/organic wastes for local production of potassium both in terms of solid potash yield and potassium recovery potential. Development of a suitable technology which can be used to extract potassium locally is recommended.

Sign in / Sign up

Export Citation Format

Share Document