Recent progress in the use of renewable energy sources to power water desalination plants

Single basin solar still with fin for enhancing productivity

The increasing need for thermal comfort has led to a rapid increase in the use of cooling systems and, consequently, electricity demand for air-conditioning systems in buildings. Heat-driven ejector refrigeration systems appear to be a promising alternative to the traditional compressor-based refrigeration technologies for energy consumption reduction. This paper presents a comprehensive literature review on ejector refrigeration systems and working fluids. It deeply analyzes ejector technology and behavior, refrigerant properties and their influence over ejector performance and all of the ejector refrigeration technologies, with a focus on past, present and future trends. The review is structured in four parts. In the first part, ejector technology is described. In the second part, a detailed description of the refrigerant properties and their influence over ejector performance is presented. In the third part, a review focused on the main jet refrigeration cycles is proposed, and the ejector refrigeration systems are reported and categorized. Finally, an overview over all ejector technologies, the relationship among the working fluids and the ejector performance, with a focus on past, present and future trends, is presented.

https://re.public.polimi.it/bitstream/11311/984261/1/2016_RSER_BesagniMereuInzoli.pdf

Ejector refrigeration: A comprehensive review

This paper provides a literature review on ejectors and their applications in refrigeration. A number of studies are grouped and discussed in several topics, i.e. background and theory of ejector and jet refrigeration cycle, performance characteristics, working fluid and improvement of jet refrigerator. Moreover, other applications of an ejector in other types of refrigeration system are also described.

Ejectors: applications in refrigeration technology

Exergy analysis, parametric analysis and optimization for a novel combined power and ejector refrigeration cycle

In falling film evaporation process, the heat is transferred from the condensing fluid side to the liquid flowing on evaporating side. Tube geometry and tube size have an important role on the performance of the falling film evaporators. The current article presents a two-dimensional computational fluid dynamics study of water falling film evaporation on a thermal spray metal coated vertical corrugated conduits. Two-phase flow simulation is carried out by using a finite volume method-based commercial software, using k-ω equations with shear stress transport. Sinusoidal corrugations with different porosity have been selected for this study. Heat and mass transfer during falling film evaporation are included through user defined functions. Effect of Reynolds number, wall superheat, and surface roughness on heat transfer coefficient is presented. Numerical results are compared with the results of horizontal circular tube, as well as corrugated plate conduits falling film evaporation from literature. An enhan...

/pdf/falling-film-evaporation-on-a-thermal-spray-metal-coated-20ta488fmd.pdf

Falling film evaporation on a thermal spray metal coated vertical corrugated plate conduits

Comparison of compact and tubular generators performance for R134a–DMF

High quality and transparent organic nonlinear optical single crystal - β alanine β alaninium picrate (βAβAP) of 12 × 8 × 3 mm in dimensions was grown by slow evaporation method. The crystal structure was confirmed by single and powder X-ray diffraction studies. The perfection of the grown crystal is justified by High resolution XRD measurement. The strain of the crystal in grain boundary was calculated from the powder XRD pattern values. The Photo luminescence’s (PL) study is also investigated to predict the optical perfection of the crystal. Optical constants like, absorption coefficient, extinction coefficient, reflection, refractive index and optical band gap are calculated using UV–Vis absorption spectrum. Optical limiting method is involving to find the linear optical absorption. The birefringence of the crystal was measured in the visible region and it was found that birefringence is dependent of wavelength. The crystal was subjected to Z-scan measurement to prove the third order non linear optical property of the crystal. The thermal stability of the crystal against the high intense laser power is measured using laser damage threshold study.

Crystal and optical perfection, linear and nonlinear optical qualities of β alanine β alaninium picrate (βAβAP) single crystal: a promising NLO crystal for optics and photonics applications

Interferometric analysis of flow around a horizontal tube falling film evaporator for MED systems

A model has been developed based on Colburn–Drew type formulation to analyze a vertical tube in tube stainless steel generator with forced convective boiling. Desorption of refrigerant vapor from refrigerant–absorbent solution takes place in the inner tube of the generator, when hot water through the annulus is used as heating medium. Simultaneous heat and mass transfer phenomena of desorption are described mathematically using the mass and energy balances, considering the heat and mass transfer resistances in liquid as well as vapor phases. Model equations are solved simultaneously by means of initial value problem solvers using explicit Runge–Kutta method with 4th order accuracy. A computer code has been developed in MATLAB to obtain the results. A parametric analysis has also been performed to study the effect of various parameters on the performance of the generator.

/pdf/numerical-studies-on-vertical-tubular-generator-in-vapor-1kzz1zcmrm.pdf

Annamalai Mani

Papers

Falling film evaporation on a thermal spray metal coated vertical corrugated plate conduits

Comparison of compact and tubular generators performance for R134a–DMF

Crystal and optical perfection, linear and nonlinear optical qualities of β alanine β alaninium picrate (βAβAP) single crystal: a promising NLO crystal for optics and photonics applications

Interferometric analysis of flow around a horizontal tube falling film evaporator for MED systems

Numerical studies on vertical tubular generator in vapor absorption refrigeration system