Experimental Analysis and Numerical Modeling of a Shell and Tube Heat Storage Unit with Phase Change Materials

In the present study, the performance of a heat storage unit consisting of number of vertical cylindrical capsules filled with phase change materials, with air flowing across them for heat exchange has been analyzed. Earlier theoretical models did not consider temperature distribution in the radial direction within the capsules, an assumption that limits their applications for small diameter capsules. The mathematical model developed in this work is based on solving the heat conduction equation in both melt and solid phases in cylindrical coordinates, taking into account the radial temperature distribution in both phases. Heat flux was then evaluated at the surface of the first row of the capsules to determine the temperature of the air leaving that row by a simple heat balance. It was found that such computation may be carried out for every few rows rather than for a single row to minimize computer time. The simulation study showed a significant improvement in the rate of heat transfer during heat charge and discharge when phase change materials with different melting temperatures were used. Air must flow in the direction of decreasing melting temperature during heat charge, while it must be reversed during heat discharge.

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An Improvement in the Solar Water Heating Systems by Thermal Storage Using Phase Change Materials

Solar Energy ◽

10.1115/isec2006-99090 ◽

2006 ◽

Cited By ~ 6

Author(s):

D. Vikram ◽

S. Kaushik ◽

V. Prashanth ◽

N. Nallusamy

Keyword(s):

Phase Change ◽

Solar Collector ◽

Storage Tank ◽

Phase Change Materials ◽

Heat Storage ◽

Control Device ◽

Hot Water ◽

Water Heater ◽

Storage Unit ◽

Solar Water

The present work has been undertaken to study the feasibility of storing solar energy using phase change materials (like paraffin) and utilizing this energy to heat water for domestic purposes during nighttime. This ensures that hot water is available through out the day. The system consists of two simultaneously functioning heat-absorbing units. One of them is a solar water heater and the other a heat storage unit consisting of Phase Change Material (PCM). The water heater functions normally and supplies hot water during the day. The storage unit stores the heat in PCMs during the day and supplies hot water during the night. The storage unit utilizes small cylinders made of aluminium, filled with paraffin wax as the heat storage medium and integrated with a Solar Collector to absorb solar heat. At the start of the day the storage unit is filled with water completely. This water is made to circulate between the solar collector and the PCM cylinders. The water in the storage tank receives heat form the solar collector and transfers it to the PCM. The PCM undergoes a phase change by absorbing latent heat, excess heat being stored as sensible heat. The water supply in the night is routed to the storage unit using a suitable control device. The heat is recovered from the unit by passing water at room temp through it. As water is drawn from the overhead tank, fresh water enters the unit disturbing the thermal equilibrium, causing flow of heat from PCM to the water. The temperature of the heated water (outlet) is varied by changing the flow rate, which is measured by a flow meter. The storage tank is completely insulated to prevent loss of heat. The performance of the present setup is compared with that of a system using same PCM encapsulated in High Density PolyEthylene (HDPE) spherical shells.

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MELTING OF NANOPARTICLE-ENHANCED PHASE CHANGE MATERIAL IN A SHELL-AND-TUBE LATENT HEAT STORAGE UNIT HEATED BY LAMINAR PULSATING FLUID FLOW

Computational Thermal Sciences An International Journal ◽

10.1615/computthermalscien.2017019067 ◽

2017 ◽

Vol 9 (4) ◽

pp. 311-334 ◽

Cited By ~ 2

Author(s):

Radouane Elbahjaoui ◽

Hamid El Qarnia

Keyword(s):

Fluid Flow ◽

Phase Change ◽

Phase Change Material ◽

Latent Heat ◽

Heat Storage ◽

Storage Unit ◽

Latent Heat Storage ◽

Shell And Tube ◽

Change Material ◽

Pulsating Fluid

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Numerical and Experimental Investigation of Shell-and-Tube Phase-Change Material Thermal Energy Storage Unit

Journal of Electronic Packaging ◽

10.1115/1.4034101 ◽

2016 ◽

Vol 138 (3) ◽

Cited By ~ 1

Author(s):

Thomas H. Sherer ◽

Yogendra Joshi

Keyword(s):

Energy Storage ◽

Phase Change ◽

Thermal Energy ◽

Thermal Energy Storage ◽

Phase Change Materials ◽

Control Volume ◽

Heat Transfer Fluid ◽

Transient Temperature ◽

Storage Unit ◽

Shell And Tube

Solid liquid phase-change materials (PCMs) present a promising approach for reducing data center cooling costs. We review prior research in this area. A shell-and-tube PCM thermal energy storage (TES) unit is then analyzed numerically and experimentally. The tube bank is filled with commercial paraffin RUBITHERM RT 28 HC PCM, which melts as the heat transfer fluid (HTF) flows across the tubes. A fully implicit one-dimensional control volume formulation that utilizes the enthalpy method for phase change has been developed to determine the transient temperature distributions in both the PCM and the tubes themselves. The energy gained by a column of tubes is used to determine the exit bulk HTF temperature from that column, ultimately leading to an exit HTF temperature from the TES unit. This paper presents a comparison of the numerical and experimental results for the transient temperature profiles of the PCM-filled tubes and HTF.

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