Heat Exchanger Performance in Latent Heat Thermal Energy Storage

1980 ◽  
Vol 102 (2) ◽  
pp. 112-118 ◽  
Author(s):  
R. N. Smith ◽  
T. E. Ebersole ◽  
F. P. Griffin
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solid Phase ◽  
Storage System ◽  
Temperature Drop ◽  
Heat Of Fusion ◽  
Analytical Prediction

An experimental study was made of the heat transfer in a component of a low temperature thermal energy storage system using latent heat of fusion of a phase change material (PCM). Measurements were made of the temperature rise of water flowing in a channel adjacent to a container filled with a freezing PCM, Gulfwax 33. In addition, temperature measurements within the PCM provided the location of the liquid/solid interface as a function of time. A simple analytical prediction is compared with the data to provide a verification of the qualitative observations. Certain multidimensional effects which occur during the freezing (discharge) mode of operation are identified especially the enhancement of freezing rates when the PCM container sidewalls (those not in contact with the heat exhange fluid) are conducting and are closely spaced. One limitation to storage systems of this type is the resistance to heat transfer of the solid phase, requiring a significant temperature drop for acceptable discharge rates. The additional “heat path” provided by the conducting container walls is shown to significantly reduce this resistance. Some observations concerning the implications for design of actual storage components are also provided.

Experimental Investigation of a Finned Mono Tube — Latent Heat Thermal Energy Storage (LHTES)

2014 ◽  
Author(s):  
Georg Urschitz ◽  
Heimo Walter ◽  
Michael Hameter
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Energy Storage ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Melting Behavior ◽  
Storage Unit ◽  
Heat Transfer Medium

The present experimental investigation covers the construction of a latent heat thermal energy storage system (LHTES), which uses sodium nitrate (NaNO3) as phase change material (PCM). The storage unit is filled with 300 kg of the PCM. For the heat transfer a vertically arranged bimetallic mono tube with longitudinal fins is used. The fins increase the heat flux into/from the PCM. Thermal oil is used as a heat transfer medium, as it allows working temperatures up to 400°C. This thermal energy storage is able to store 60 kWh of thermal energy and can be loaded with a power up to 200 kW. One part of the investigation results presented in this paper was the determination of the storable energy and the comparison with data from literature and calculations. Additionally, the melting behavior of the PCM was measured with temperature sensors located at different positions over the height of the storage unit. Finally, the entrance of the heat transfer medium was changed from the top to the bottom of the thermal energy storage unit and a different melting behavior could be detected.

Design of a Modular Latent Heat Storage System for Solar Thermal Power Plants

2011 ◽  
Author(s):  
Mark R. Campbell ◽  
Marc Newmarker ◽  
Nathaniel Lewis ◽  
Christopher T. George ◽  
Gilbert Cohen
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Heat Transfer Surface ◽  
Change Material

Thermal energy storage systems designed to use phase change material can benefit from accounting for the reduction in heat transfer that results from fouling on the heat transfer surface or employing a system to minimize the amount of build-up on the heat transfer surface. This paper describes the modeling and design of a modular latent heat thermal energy storage system that can use an internal heat exchanger and a mechanical system to increase heat transfer to and from the phase change material. Theoretical heat transfer modeling of a 100 kWht storage system was performed, candidate phase change materials were tested, and mechanical material removal experiments were conducted. The results of this work led to a design that is in construction and will be operated in the future. The system is predicted to be capable of reaching 93% round trip efficiency while providing 2 hours of discharge at a nearly constant temperature.

scholarly journals Latent Heat Phase Change Heat Transfer of a Nanoliquid with Nano–Encapsulated Phase Change Materials in a Wavy-Wall Enclosure with an Active Rotating Cylinder

2021 ◽  
Vol 13 (5) ◽  
pp. 2590
Author(s):  
S. A. M. Mehryan ◽  
Kaamran Raahemifar ◽  
Leila Sasani Gargari ◽  
Ahmad Hajjar ◽  
Mohamad El Kadri ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Wavy Wall ◽  
Governing Equations ◽  
Stefan Number ◽  
Change Material

A Nano-Encapsulated Phase-Change Material (NEPCM) suspension is made of nanoparticles containing a Phase Change Material in their core and dispersed in a fluid. These particles can contribute to thermal energy storage and heat transfer by their latent heat of phase change as moving with the host fluid. Thus, such novel nanoliquids are promising for applications in waste heat recovery and thermal energy storage systems. In the present research, the mixed convection of NEPCM suspensions was addressed in a wavy wall cavity containing a rotating solid cylinder. As the nanoparticles move with the liquid, they undergo a phase change and transfer the latent heat. The phase change of nanoparticles was considered as temperature-dependent heat capacity. The governing equations of mass, momentum, and energy conservation were presented as partial differential equations. Then, the governing equations were converted to a non-dimensional form to generalize the solution, and solved by the finite element method. The influence of control parameters such as volume concentration of nanoparticles, fusion temperature of nanoparticles, Stefan number, wall undulations number, and as well as the cylinder size, angular rotation, and thermal conductivities was addressed on the heat transfer in the enclosure. The wall undulation number induces a remarkable change in the Nusselt number. There are optimum fusion temperatures for nanoparticles, which could maximize the heat transfer rate. The increase of the latent heat of nanoparticles (a decline of Stefan number) boosts the heat transfer advantage of employing the phase change particles.

Sign in / Sign up

Export Citation Format

Share Document