Latent Thermal Storage Unit Using Form-Stable High Density Polyethylene; Part I: Performance of the Storage Unit

1986 ◽  
Vol 108 (4) ◽  
pp. 282-289 ◽  
Author(s):  
M. Kamimoto ◽  
Y. Abe ◽  
S. Sawata ◽  
T. Tani ◽  
T. Ozawa
Keyword(s):  
Heat Transfer ◽  
High Density Polyethylene ◽  
Direct Contact ◽  
Thermal Storage ◽  
High Density ◽  
Heat Transfer Fluid ◽  
Contact Heat ◽  
Storage Unit ◽  
Contact Heat Transfer ◽  
Solar Thermal Applications

A latent thermal storage unit of 30 kWh using form-stable high density polyethylene (HDPE) rods has been developed mainly for solar thermal applications, and heat transfer experiments have been carried out. A direct contact heat transfer technique between HDPE rods and ethylene glycol (EG: a heat transfer fluid) is adopted. Charge and discharge characteristics have been obtained for various thermal input/output and different initial temperature profiles in the storage unit. The direct contact heat transfer and a formation of a clear thermocline provide a good performance for all the cases. Discussions are given of thermal efficiency, storage density, and thermal insulation.

Latent Thermal Storage Unit Using Form-Stable High Density Polyethylene; Part II: Numerical Analysis of Heat Transfer

1986 ◽  
Vol 108 (4) ◽  
pp. 290-297 ◽  
Author(s):  
M. Kamimoto ◽  
Y. Abe ◽  
K. Kanari ◽  
Y. Takahashi ◽  
T. Tani ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Computer Simulation ◽  
Numerical Analysis ◽  
High Density Polyethylene ◽  
Thermal Storage ◽  
High Density ◽  
Storage Unit ◽  
Discharge Characteristics ◽  
One Dimensional ◽  
Finite Difference Equations

Heat transfer in the latent thermal storage unit using form-stable high density polyethylene rods has been numerically analyzed. The analysis is based on simple explicit one-dimensional finite difference equations. The calculation can well simulate both the charge and discharge characteristics of the prototype storage unit developed by the present authors. The computer simulation has been used also to speculate the performance of the storage unit under various conditions. Effects of several parameters on the discharge characteristics have been quantitatively made clear.

Charge and Discharge Characteristics of a Direct Contact Latent Thermal Energy Storage Unit Using Form-Stable High-Density Polyethylene

1984 ◽  
Vol 106 (4) ◽  
pp. 465-474 ◽  
Author(s):  
Y. Abe ◽  
Y. Takahashi ◽  
R. Sakamoto ◽  
K. Kanari ◽  
M. Kamimoto ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
High Density Polyethylene ◽  
Direct Contact ◽  
High Density ◽  
Storage Unit ◽  
Discharge Characteristics ◽  
Energy Storage Unit

For solar thermal energy utilization in relatively low temperatures, a lab-scale direct contact, latent thermal energy storage unit using a form-stable high-density polyethylene (HDPE) was developed. The phase change material (PCM), the form-stable HDPE, does not fluidize nor adhere even after melting, and this particular property permits a direct contact heat transfer between the PCM and a heat transfer fluid (HTF). The storage column in the present study consists of a bundle of vertically arranged thin HDPE rods, where HTF flows in the axial direction and contacts with the HDPE surface directly. A series of experiments were performed for both charge and discharge modes under conditions of different flow rates, initial temperatures in the column, and HTF inlet temperatures. A numerical simulation was also made to study further detailed performance of the storage unit. The charge and discharge characteristics of the storage unit are discussed.

scholarly journals Effective Separation of a Water in Oil Emulsion from a Direct Contact Latent Heat Storage System

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2264 ◽  
Author(s):  
Sebastian Ammann ◽  
Andreas Ammann ◽  
Rebecca Ravotti ◽  
Ludger Fischer ◽  
Anastasia Stamatiou ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Latent Heat ◽  
Direct Contact ◽  
Heat Storage ◽  
Storage System ◽  
Heat Transfer Fluid ◽  
Storage Unit ◽  
Latent Heat Storage ◽  
Oil Emulsion ◽  
Water In Oil Emulsion

The problem of emulsification between Phase Change Material (PCM) and Heat Transfer Fluid (HTF) in direct contact latent heat storage systems has been reported in various studies. This issue causes the PCM to flow out of the storage tank and crystallize at unwanted locations and thus presents a major limitation for the proper operation of such systems. These anomalies become more pronounced when high HTF flow rates are employed with the aim to achieve fast heat transfer rates. The goal of this paper is to find a method which will enable the fast separation of the formed emulsion and thus the uninterrupted operation of the storage unit. In this study, three separation methods were examined and the use of superhydrophobic filters was chosen as the best candidate for the demulsification of the PCM and HTF mixtures. The filter was produced by processing of a melamine sponge with different superhydrophobic adhesives and was tested with emulsions closely resembling the ones formed in a real direct contact setup. The superhydrophobic filter obtained, was able to separate the emulsions effectively while presenting a very high permeability (up to 1,194,980 kg h−1 m−2 bar−1). This is the first time the use of a superhydrophobic sponge has been investigated in the context of demulsification in direct contact latent heat storage.

Increasing efficiency in direct contact heat transfer

1987 ◽  
Vol 6 (4) ◽  
pp. 208-210 ◽  
Author(s):  
Ralph F. Strigle ◽  
Tsuneo Nakano
Keyword(s):  
Heat Transfer ◽  
Direct Contact ◽  
Contact Heat ◽  
Contact Heat Transfer

An Analysis of a Direct Contact Ice Slurry Generator

2008 ◽  
Author(s):  
M. A. Wahed ◽  
M. N. A. Hawlader
Keyword(s):  
Heat Transfer ◽  
Simulation Model ◽  
Direct Contact ◽  
Coolant Flow ◽  
Temperature Profiles ◽  
Ice Slurry ◽  
Generation System ◽  
Contact Heat ◽  
Flow Rates ◽  
Contact Heat Transfer

Attempts have been made to study an ice slurry generation system where two immiscible liquids, water and a coolant, are used to produce ice slurry by direct contact heat transfer. A mathematical model has been developed to evaluate the heat transfer phenomena between the coolant drops and the water in the ice slurry generation system. In this process, all the important variables that affect the direct contact heat transfer between these two fluids were incorporated into the simulation model to evaluate thermal performance of the system. Experiments were performed on an ice slurry generator using water and an immiscible liquid coolant, Fluroinert FC-84. The coolant at about −10°C to −15°C was delivered to the top of the ice slurry generator containing water and collected from the bottom for recirculation. The measured temperature profiles of water in the ice slurry generator for different coolant flow rates (8 lit/min to 12 lit/min) showed a good agreement with those temperature profiles obtained from the simulation model. These results validated the simulation model developed for the ice slurry generator. The analysis showed that during sensible cooling, the estimated heat transfer coefficients between water and the coolant were in the range of 3.0 to 6.5 kW/m2 for coolant flow rates varying from 8 lit/min to 12 lit/min. Higher coolant flow rates also enhanced the ice formation process due to the increased heat transfer rate. In addition, it was also observed that the ice production increased significantly when the nozzle was placed at the bottom of the ice slurry generator.

Direct contact heat transfer with change of phase

1970 ◽  
Vol 13 (6) ◽  
pp. 945-956 ◽  
Author(s):  
M Bentwich ◽  
U Landau ◽  
S Sideman
Keyword(s):  
Heat Transfer ◽  
Direct Contact ◽  
Contact Heat ◽  
Contact Heat Transfer
Sign in / Sign up

Export Citation Format

Share Document