scholarly journals Comparative Study of Shallow Solar Ponds with Different Depths

2017 ◽  
Vol 13 (1) ◽  
pp. 13-28
Author(s):  
K Shanmugasundaram B Janarthanan
Keyword(s):  
Energy Balance ◽  
Comparative Study ◽  
Pond Water ◽  
Maximum Temperature ◽  
Balance Equations ◽  
Solar Ponds ◽  
Glass Cover ◽  
Solar Pond ◽  
Different Depths

In this paper, an attempt has been made to design and construct the shallow solar ponds with different depths such as 0.06 m and 0.15 m at Coimbatore (11 ͦ - latitude and 77 ͦ - longitudes), Tamilnadu, and India. The experiments have been carried out during the period from January-March 2012. The energy balance equations have been written for different elements of the two shallow solar ponds such as upper glass cover, lower glass cover and pond water and solved analytically. The performance of the two shallow solar ponds has been compared and found that the maximum temperature of the pond water in different depths (0.06 m and 0.15 m) of shallow solar pond is found to be 57  C and 42  C.

Comparative Productivity of Distillation and Reverse Osmosis Desalination Using Energy From Solar Ponds

1982 ◽  
Vol 104 (4) ◽  
pp. 299-304 ◽  
Author(s):  
B. W. Tleimat ◽  
E. D. Howe
Keyword(s):  
Reverse Osmosis ◽  
Electrical Power ◽  
Water System ◽  
Rankine Cycle ◽  
Pond Water ◽  
Generator System ◽  
Solar Ponds ◽  
Solar Pond ◽  
Salt Gradient ◽  
Hydrocarbon Vapor

This paper presents comparative analyses of two methods for producing desalted water using the heat collected by a solar pond—the first by distillation, and the second by reverse osmosis. The distillation scheme uses a multiple-effect distiller supplied with steam generated in a flash boiler using heat from a solar pond. Solar pond water passes through a heat exchanger in the water system ahead of the flash boiler. The second scheme uses a similar arrangement to generate hydrocarbon vapor which drives a Rankine cycle engine. This engine produces mechanical/electrical power for the RO plant. The analyses use two pond water temperatures—82.2°C (180°F) and 71.1°C (160°F)—which seem to cover the range expected from salt-gradient ponds. In each case, the pond water temperature drops by 5.56°C (10°F) while passing through the vapor generator system. Results of these analyses show that, based on the assumptions made, desalted water could be produced by distillation at productivity rates much greater than those estimated for the RO plant.

scholarly journals Theoretical Analysis of a New Design of a Concentration Based Solar Distiller

2021 ◽  
Vol 234 ◽  
pp. 00003
Author(s):  
Mokhtar Mohammed ◽  
Taha Janan Mourad
Keyword(s):  
Energy Balance ◽  
Theoretical Analysis ◽  
Brackish Water ◽  
Theoretical Study ◽  
Balance Equations ◽  
New Device ◽  
Numerical Resolution ◽  
Matlab Code ◽  
Glass Cover ◽  
Theoretical Performance

This paper includes a theoretical study of energy balance for all parts of new design of solar concentration distiller using a parabolic concentrator with a half-cylinder basin. Our goal is to analyze the thermal efficiency of the new device to use in the Morocco's Rabat-Sale-Kenitra region. The methodology concentrates on solving the thermal collector's energy balance equations whose components are the glass cover, the brackish water and half-cylinder absorber. Numerical resolution of the energy balance equations was performed using a MATLAB code based on the method of 4th order Runge-Kutta. The results show a good theoretical performance of the new device.

Effects of Ambipolar Diffusion on Prominence Thread Models

1994 ◽  
Vol 144 ◽  
pp. 315-321 ◽  
Author(s):  
M. G. Rovira ◽  
J. M. Fontenla ◽  
J.-C. Vial ◽  
P. Gouttebroze
Keyword(s):  
Energy Balance ◽  
Transition Region ◽  
Ambipolar Diffusion ◽  
Line Profiles ◽  
Balance Equations ◽  
Model Calculations ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Partial Frequency Redistribution ◽  
Theoretical Structure

AbstractWe have improved previous model calculations of the prominence-corona transition region including the effect of the ambipolar diffusion in the statistical equilibrium and energy balance equations. We show its influence on the different parameters that characterize the resulting prominence theoretical structure. We take into account the effect of the partial frequency redistribution (PRD) in the line profiles and total intensities calculations.

Parametric Study of Photovoltaic Thermal Solar Collector Using An Improved Parallel Flow

2020 ◽  
Vol 2 (1) ◽  
pp. 19-24
Author(s):  
Sakhr Mohammed Sultan ◽  
Chih Ping Tso ◽  
Ervina Efzan Mohd Noor ◽  
Fadhel Mustafa Ibrahim ◽  
Saqaff Ahmed Alkaff
Keyword(s):  
Thermal Conductivity ◽  
Energy Balance ◽  
Parametric Study ◽  
Solar Collector ◽  
Parallel Flow ◽  
Operating Conditions ◽  
Balance Equations ◽  
Conductivity Type ◽  
Pv Module ◽  
Sunny Weather

Photovoltaic Thermal Solar Collector (PVT) is a hybrid technology used to produce electricity and heat simultaneously. Current enhancements in PVT are to increase the electrical and thermal efficiencies. Many PVT factors such as type of absorber, thermal conductivity, type of PV module and operating conditions are important parameters that can control the PVT performance. In this paper, an analytical model, using energy balance equations, is studied for PVT with an improved parallel flow absorber. The performance is calculated for a typical sunny weather in Malaysia. It was found that the maximum electrical and thermal efficiencies are 12.9 % and 62.6 %, respectively. The maximum outlet water temperature is 59 oC.

Thermal Performance Analysis of a Rectangular Longitudinal Finned Solar Air Heater With Semicircular Absorber Plate

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Satyender Singh ◽  
Prashant Dhiman
Keyword(s):  
Thermal Performance ◽  
Numerical Solutions ◽  
Solar Air Heater ◽  
Duct Flow ◽  
Balance Equations ◽  
Absorber Plate ◽  
Ansys Fluent ◽  
Air Heater ◽  
Glass Cover ◽  
Good Agreement

Thermal performance of a single-pass single-glass cover solar air heater consisting of semicircular absorber plate finned with rectangular longitudinal fins is investigated. The analysis is carried out for different hydraulic diameters, which were obtained by varying the diameter of the duct from 0.3–0.5 m. One to five numbers of fins are considered. Reynolds number ranges from 1600–4300. Analytical solutions for energy balance equations of different elements and duct flow of the solar air heater are presented; results are compared with finite-volume methodology based numerical solutions obtained from ansys fluent commercial software, and a fairly good agreement is achieved. Moreover, analysis is extended to check the effect of double-glass cover and the recycle of the exiting air. Results revealed that the use of double-glass cover and recycle operation improves the thermal performance of solar air heater.

The Efficiency of Tidal Fences: A Brief Review and Further Discussion on the Effect of Wake Mixing

2013 ◽  
Author(s):  
Takafumi Nishino ◽  
Richard H. J. Willden
Keyword(s):  
Energy Balance ◽  
Theoretical Investigation ◽  
Three Dimensional ◽  
Physical Factors ◽  
Balance Equations ◽  
Order Model ◽  
Near Wake ◽  
New Model ◽  
Actuator Disk ◽  
Limiting Efficiency

Recent discoveries on the limiting efficiency of tidal fences are reviewed, followed by a new theoretical investigation into the effect of wake mixing on the efficiency of ‘full’ tidal fences (i.e. turbines arrayed regularly across an entire channel span). The new model is based on the momentum and energy balance equations but includes several unclosed terms, which depend on the actual (three-dimensional) characteristics of turbine near-wake mixing and therefore need to be modelled empirically. The new model agrees well with three-dimensional actuator disk simulations when those unclosed terms are assessed based on the simulations themselves, suggesting that this low-order model could serve as a basis to analyse how various physical factors (such as the design of turbines) affect the limiting efficiency of tidal fences via changes in those terms describing the characteristics of turbine near-wake mixing. Also discussed is the effect of wake mixing on the efficiency of ‘partial’ tidal fences.

scholarly journals Evaluation of Solar Ponds and Aplication Area

2018 ◽  
Vol 64 ◽  
pp. 02002
Author(s):  
Sogukpinar Haci ◽  
Bozkurt Ismail ◽  
Cag Serkan
Keyword(s):  
Solar Energy ◽  
Electricity Generation ◽  
Storage Capacity ◽  
Heat Storage ◽  
Storage Systems ◽  
Hot Water ◽  
Temperature Variations ◽  
Solar Ponds ◽  
Salty Water ◽  
Solar Pond

Solar ponds are heat storage systems where solar energy is collected and stored thermally. Solar ponds were discovered during the temperature variations in the lower regions of existing saltwater pond in the area is found to be higher than their surface. Later, it was constructed artificially and started to be used. These systems have heat storage capacity at moderate temperatures. Solar pons are used in many areas such as electricity generation, heating the environment, meeting the need of hot water, drying food and obtaining fresh water from salty water. In this study, the studies about solar ponds were summarized, the construction of solar pond was explained, and the application areas were examined.

scholarly journals Electromagnetic Energy Balance Equations and Poynting Theorem

2020 ◽  
Author(s):  
gaobiao xiao
Keyword(s):  
Energy Balance ◽  
Flux Density ◽  
Poynting Vector ◽  
Power Balance ◽  
Time Varying ◽  
Balance Equations ◽  
Power Flux ◽  
Modified Method ◽  
Electromagnetic Power ◽  
Poynting Theorem

<p>Poynting theorem plays a very important role in analyzing electromagnetic phenomena. The electromagnetic power flux density is usually expressed with the Poynting vector. However, since Poynting theorem basically focuses on the power balance in a system, it is not so convenient in some situations to use it for evaluating the electromagnetic energies. The energy balance issue for time varying fields is revisited in this paper, and a set of energy balance equations are introduced, and a modified method for evaluating power flux is proposed.</p>

Sign in / Sign up

Export Citation Format

Share Document