Energetic and exergetic analysis of N partially covered photovoltaic thermal-compound parabolic concentrator (PVT-CPC) collectors connected in series

Solar Energy ◽  
2016 ◽  
Vol 137 ◽  
pp. 441-451 ◽  
Author(s):  
Rohit Tripathi ◽  
G.N. Tiwari
Keyword(s):  
Compound Parabolic Concentrator ◽  
In Series ◽  
Exergetic Analysis

scholarly journals Performance analysis of N-identical PVT-CPC collectors an active single slope solar distiller with a helically coiled heat exchanger using CuO nanoparticles

2021 ◽  
Author(s):  
Dharamveer ◽  
Samsher ◽  
Anil Kumar
Keyword(s):  
Heat Exchanger ◽  
Performance Analysis ◽  
Flat Plate ◽  
Thermal Energy ◽  
Cuo Nanoparticles ◽  
Analytical Expression ◽  
Compound Parabolic Concentrator ◽  
In Series ◽  
Performance Analyses ◽  
Flat Plate Collector

Abstract This paper presents performance analyses based on temperatures, thermal energy (overall), thermal exergy (overall), electrical exergy, and yield of the systems that have been investigated. In the present study, an analytical expression of N-identical partly covered photovoltaic compound parabolic concentrator collector connected in series (N-PVT-CPC-SS-HE) an active single slope solar distiller unit helically coiled heat exchanger has been found. The performance analyses of the proposed system have been executed for 0.25% concentration of CuO nanoparticles for collectors (N = 4), fluid flowing rate 0.02 kg/s in 280 kg mass of basin fluid. The system's performance is compared with N-identical partly covered photovoltaic flat plate collector connected in series (N-PVT-FPC-DS-HE) an active double slope solar distiller unit with helically coiled heat exchanger previous system ref (Sahota and Tiwari 2017). The thermal energy 112,109.1 kwh, thermal exergy 312.07 kwh, and yield 3,615.05 kg annually. It is found that enhancement daily in thermal energy of the proposed system with CuO nanoparticles than the previous system with various nanofluids CuO, Al2O3, TiO2, and water are found 16.75%, 51.13%, 61.82%, and 80.67% more significant correspondingly. The enhancement in yield of the proposed system is obtained for CuO nanoparticles greater than the previous system with CuO 11.19%, Al2O3 17.2%, TiO2 26.25%, and water 32.17% greater. The electrical exergy is almost the same as the previous system.

The Shikani HME: A New Tracheostomy Heat and Moisture Exchanger

2020 ◽  
Vol 63 (9) ◽  
pp. 2921-2929
Author(s):  
Alan H. Shikani ◽  
Elamin M. Elamin ◽  
Andrew C. Miller
Keyword(s):  
Ex Vivo ◽  
Moisture Loss ◽  
Speaking Valve ◽  
Time Zero ◽  
In Series ◽  
Turbulent Airflow ◽  
The Difference ◽  
Loss Efficiency ◽  
Heat And Moisture ◽  
Lung Simulation

Purpose Tracheostomy patients face many adversities including loss of phonation and essential airway functions including air filtering, warming, and humidification. Heat and moisture exchangers (HMEs) facilitate humidification and filtering of inspired air. The Shikani HME (S-HME) is a novel turbulent airflow HME that may be used in-line with the Shikani Speaking Valve (SSV), allowing for uniquely preserved phonation during humidification. The aims of this study were to (a) compare the airflow resistance ( R airflow ) and humidification efficiency of the S-HME and the Mallinckrodt Tracheolife II tracheostomy HME (M-HME) when dry (time zero) and wet (after 24 hr) and (b) determine if in-line application of the S-HME with a tracheostomy speaking valve significantly increases R airflow over a tracheostomy speaking valve alone (whether SSV or Passy Muir Valve [PMV]). Method A prospective observational ex vivo study was conducted using a pneumotachometer lung simulation unit to measure airflow ( Q ) amplitude and R airflow , as indicated by a pressure drop ( P Drop ) across the device (S-HME, M-HME, SSV + S-HME, and PMV). Additionally, P Drop was studied for the S-HME and M-HME when dry at time zero (T 0 ) and after 24 hr of moisture testing (T 24 ) at Q of 0.5, 1, and 1.5 L/s. Results R airflow was significantly less for the S-HME than M-HME (T 0 and T 24 ). R airflow of the SSV + S-HME in series did not significant increase R airflow over the SSV or PMV alone. Moisture loss efficiency trended toward greater efficiency for the S-HME; however, the difference was not statistically significant. Conclusions The turbulent flow S-HME provides heat and moisture exchange with similar or greater efficacy than the widely used laminar airflow M-HME, but with significantly lower resistance. The S-HME also allows the innovative advantage of in-line use with the SSV, hence allowing concurrent humidification and phonation during application, without having to manipulate either device.

Status of nondestructive control of transport function metal products at JSC EVRAZ NTMK

2020 ◽  
Vol 76 (6) ◽  
pp. 586-590
Author(s):  
S. P. Bersenev ◽  
E. M. Slobtsova
Keyword(s):  
Crack Detection ◽  
Middle Part ◽  
Control Line ◽  
Magnetic Powder ◽  
Nondestructive Control ◽  
Automated Control ◽  
Ultrasonic Control ◽  
Acoustic Contact ◽  
In Series

Achievements in the area of automated ultrasonic control of quality of rails, solid-rolled wheels and tyres, wheels magnetic powder crack detection, carried out at JSC EVRAZ NTMK. The 100% nondestructive control is accomplished by automated control in series at two ultrasonic facilities RWI-01 and four facilities УМКК-1 of magnetic powder control, installed into the exit control line in the wheel-tyre shop. Diagram of location, converters displacement and control operations in the process of control at the facility RWI-01 presented, as well as the structural diagram of the facility УМКК-1. The automated ultrasonic control of rough tyres is made in the tyres control line of the wheel-tyre shop at the facility УКБ-1Д. The facility enables to control internal defects of tyres in radial, axis and circular directions of radiation. Possibilities of the facility УКБ-1Д software were shown. Nondestructive control of railway rails is made at two facilities, comprising the automated control line of the rail and structural shop. The УКР-64Э facility of automated ultrasonic rails control is intended to reveal defects in the area of head, web and middle part of rail foot by pulse echo-method with a immersion acoustic contact. The diagram of rail P65 at the facility УКР-64Э control presented. To reveal defects of the macrostructure in the area of rail head and web by mirror-shadow method, an ultrasonic noncontact electromagnetic-acoustic facility is used. It was noted, that implementation of the 100% nondestructive control into the technology of rolled stuff production enabled to increase the quality of products supplied to customers and to increase their competiveness.

Dimensions of plane and solid angles and their units in the International System of Units (SI)

2020 ◽  
pp. 26-32
Author(s):  
M. I. Kalinin ◽  
L. K. Isaev ◽  
F. V. Bulygin
Keyword(s):  
Solid Angle ◽  
International System ◽  
International Committee ◽  
Plane Angle ◽  
Arc Length ◽  
Weights And Measures ◽  
International System Of Units ◽  
System Of Units ◽  
In Series ◽  
Solid Angles

The situation that has developed in the International System of Units (SI) as a result of adopting the recommendation of the International Committee of Weights and Measures (CIPM) in 1980, which proposed to consider plane and solid angles as dimensionless derived quantities, is analyzed. It is shown that the basis for such a solution was a misunderstanding of the mathematical formula relating the arc length of a circle with its radius and corresponding central angle, as well as of the expansions of trigonometric functions in series. From the analysis presented in the article, it follows that a plane angle does not depend on any of the SI quantities and should be assigned to the base quantities, and its unit, the radian, should be added to the base SI units. A solid angle, in this case, turns out to be a derived quantity of a plane angle. Its unit, the steradian, is a coherent derived unit equal to the square radian.

Exergy and sensibility analysis of each individual effect in a kraft multiple effect evaporator

TAPPI Journal ◽  
2019 ◽  
Vol 18 (10) ◽  
pp. 607-618
Author(s):  
JÉSSICA MOREIRA ◽  
BRUNO LACERDA DE OLIVEIRA CAMPOS ◽  
ESLY FERREIRA DA COSTA JUNIOR ◽  
ANDRÉA OLIVEIRA SOUZA DA COSTA
Keyword(s):  
Optimization Problem ◽  
Real Data ◽  
Kraft Pulping ◽  
Steam Temperature ◽  
Input Flow ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Multiple Effect ◽  
Sensibility Analysis ◽  
Exergetic Analysis

The multiple effect evaporator (MEE) is an energy intensive step in the kraft pulping process. The exergetic analysis can be useful for locating irreversibilities in the process and pointing out which equipment is less efficient, and it could also be the object of optimization studies. In the present work, each evaporator of a real kraft system has been individually described using mass balance and thermodynamics principles (the first and the second laws). Real data from a kraft MEE were collected from a Brazilian plant and were used for the estimation of heat transfer coefficients in a nonlinear optimization problem, as well as for the validation of the model. An exergetic analysis was made for each effect individually, which resulted in effects 1A and 1B being the least efficient, and therefore having the greatest potential for improvement. A sensibility analysis was also performed, showing that steam temperature and liquor input flow rate are sensible parameters.

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