On Thermoeconomics of a Sensible Heat, Thermal Energy Storage System

1995 ◽  
Vol 117 (3) ◽  
pp. 255-259 ◽  
Author(s):  
M. A. Badar ◽  
S. M. Zubair
Keyword(s):  
Heat Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Optimum Number ◽  
Sensible Heat ◽  
Hot Gas ◽  
Gas Source ◽  
Charging Time ◽  
Thermal Energy Storage System ◽  
Form Model

A closed-form model for the second-law-based thermoeconomic optimization of a sensible heat storage system, in which the energy is stored in a large liquid bath from a hot-gas source, is discussed with an example problem. The results are compared with those obtained from Bejan’s analysis to illustrate usefulness of the present approach. The influence of important parameters on the optimum number of heat transfer units Ntu,opt, and dimensionless charging time θopt, are presented in a graphic form.

Performance of Latent Heat Solar Thermal Energy Storage System Using Various Heat Transfer Fluids

2015 ◽  
Vol 787 ◽  
pp. 27-31
Author(s):  
M. Gajendiran ◽  
P.M. Sivaram ◽  
N. Nallusamy
Keyword(s):  
Energy Storage ◽  
Ethylene Glycol ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Solar Thermal Energy ◽  
Heat Transfer Fluids ◽  
Charging Time ◽  
Thermal Energy Storage System

In the present work the thermal performance of Phase Change Material (PCM) based solar thermal energy storage system under the influence of different heat transfer fluids (HTF) have been investigated. Water, Ethylene Glycol–water and Copper nanofluid are selected as HTF. Paraffin is used as PCM and encapsulated in cylindrical capsules. The thermal energy storage (TES) tank acts as a storage unit consisting PCM capsules packed in three beds surrounded by water, which acts as sensible heat storage (SHS) material. HTF circulated by a pump transfers heat from solar flat plate collector (FPC) to the TES tank. 25% ethylene glycol -75% water HTF is prepared by mixing ethylene glycol (EG) with water. Copper-distilled water nanofluids (0.3% by weight) are prepared using prolonged sonication with sodium dodecyl benzene sulphonate (SDBS) as the surfactant. Various performance parameters such as charging time, instantaneous heat stored, cumulative heat stored and system efficiency are studied for various HTFs. It is found that the charging time is reduced by 33.3% for copper nanofluid and 22.2% for ethylene glycol- water mixture HTFs. It is also observed that there is an increase in system efficiency and cumulative heat stored with reference to charging time for these HTFs when compared with conventional HTF 1 i.e. water.

Experimental Investigation of Latent Heat Thermal Energy Storage System Enhanced by Annular and Radial Fins

2021 ◽  
Author(s):  
Saeed Tiari ◽  
Addison Hockins ◽  
Samantha Moretti
Keyword(s):  
Energy Storage ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Energy System ◽  
Energy Storage System ◽  
Heat Transfer Fluid ◽  
Charging Time ◽  
Thermal Energy Storage System

Abstract In the current study, the thermal characteristics of a latent heat thermal energy storage system enhanced with annular and radial fins are investigated experimentally. Rubitherm RT-55 is used as the phase change material (PCM) and is enclosed within a vertical cylindrical container. Water is used as the heat transfer fluid (HTF) which is circulated in a copper pipe that passes through the center of the container. The hot HTF is circulated through the system until the entire mass of solid PCM inside the container is melted. Twelve k-type thermocouples are inserted into the container at different levels to monitor the PCM temperature during the charging processes. A thermal imaging camera is used to take thermal images of the latent heat thermal energy system as it operates. The effects of different number of annular and radial fins attached to the central pipe on the thermal performance of the latent heat thermal energy storage system during the charging processes have been studied. It was found that the inclusion of 10 and 20 annular fins decreased the charging time by 79.5% and 82.8%, respectively. The two radial fin designs of 4 fins and 8 fins were assessed and found to decrease charging time by 81.9% and 86.6%, respectively.

Thermoeconomic Optimization of a Sensible-Heat Thermal-Energy-Storage System: A Complete Storage Cycle

1999 ◽  
Vol 121 (4) ◽  
pp. 286-294 ◽  
Author(s):  
S. M. Zubair ◽  
M. A. Al-Naglah
Keyword(s):  
Heat Transfer ◽  
Temperature Difference ◽  
Storage System ◽  
Unit Cost ◽  
Energy Storage System ◽  
Dimensionless Temperature ◽  
Optimum Number ◽  
Sensible Heat ◽  
Storage Element ◽  
Cost Rate

An analytical model for the second-law-based thermoeconomic analysis and optimization of a sensible-heat-storage system is derived and discussed, in which the storage element is both heated and cooled by flowing streams of gases. In this analysis, monetary values are attached to the irreversible losses caused by the finite temperature difference heat transfer and pressure drop in the storage system. Important dimensionless parameters are identified and the results are presented in terms of the optimum dimensionless charging time θS,opt as a function of a dimensionless temperature difference τ, as well as the optimum number of heat transfer units NTUS,opt, as a function of the dimensionless unit cost per unit heat conductance γUA and τ of the storage systems. The systems analyzed are optimized by introducing a new performance criterion described as the cost rate number, Γ*. Several example problems are also presented and the results are compared with that obtained from Krane’s analysis to illustrate the usefulness of the present approach. The influence of important unit cost parameters on NTUS,opt and θS,opt, are also studied in somewhat more detail.

Second Law Optimization of a Sensible Heat Thermal Energy Storage System With a Distributed Storage Element—Part 1: Development of the Analytical Model

1991 ◽  
Vol 113 (1) ◽  
pp. 20-26 ◽  
Author(s):  
M. J. Taylor ◽  
R. J. Krane ◽  
J. R. Parsons
Keyword(s):  
Energy Storage ◽  
Analytical Model ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Distributed Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Sensible Heat ◽  
Storage Element ◽  
Thermal Energy Storage System

This study explores the behavior of a flat-slab, sensible heat thermal energy storage system, the physical design and operation of which have been optimized to minimize the production of entropy by thermodynamic irreversibilities. Unlike many previous studies, the present work includes the entropy production by transient heat conduction within the storage element; that is, the analytical model is based on a distributed, as opposed to a lumped, storage element. The work is presented in two parts. The development of the analytical model required to compute the figure of merit, which is called the entropy generation number, in terms of the design and operational parameters of the system is presented in Part I. In Part II, the numerical solution of the analytical model is discussed and the results of an optimization study are presented and interpreted.

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