Computational analysis of a pipe flow distributor for a thermocline based thermal energy storage system

Journal Article · Mon Sep 16 00:00:00 EDT 2013 · Journal of Solar Energy Engineering

DOI:https://doi.org/10.1115/1.4024927· OSTI ID:1358426

Afrin, Samia ^[1]; Kumar, Vinod ^[1]; Bharathan, Desikan ^[1]; Glatzmaier, Greg C. ^[2]; Ma, Zhiwen ^[2]

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1. Univ. of Texas at El Paso, El Paso, TX (United States)
2. National Renewable Energy Lab. (NREL), Golden, CO (United States)

In this paper, the overall efficiency of a concentrating solar power (CSP) plant depends on the effectiveness of thermal energy storage (TES) system. A single tank TES system consists of a thermocline region which produces the temperature gradient between hot and cold storage fluid by density difference. Preservation of this thermocline region in the tank during charging and discharging cycles depends on the uniformity of the velocity profile at any horizontal plane. Our objective is to maximize the uniformity of the velocity distribution using a pipe-network distributor by varying the number of holes, distance between the holes, position of the holes and number of distributor pipes. For simplicity, we consider that the diameter of the inlet, main pipe, the distributor pipes and the height and the width of the tank are constant. We use Hitec^® molten salt as the storage medium and the commercial software Gambit 2.4.6 and Fluent 6.3 for the computational analysis. We analyze the standard deviation in the velocity field and compare the deviations at different positions of the tank height for different configurations. Since the distance of the holes from the inlet and their respective arrangements affects the flow distribution throughout the tank; we investigate the impacts of rearranging the holes position on flow distribution. Impact of the number of holes and distributor pipes are also analyzed. We analyze our findings to determine a configuration for the best case scenario.

• Research Organization: Univ. of Texas at El Paso, El Paso, TX (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• Contributing Organization: NRLE
• DOE Contract Number: EE0004008
• OSTI ID: 1358426
• Journal Information: Journal of Solar Energy Engineering, Vol. 136, Issue 2; Related Information: EE0004008; ISSN 0199-6231
• Publisher: ASME
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
thermal energy storage
concentrated solar power
thermocline
molten salt
CFD
pipe flow
pipes
flow (dynamics)
fluids
storage
renewable energy
computer software
temperature gradient
cycles