scholarly journals Visualization for Temperature Change on Phase Change of Water using Thermal Image Camera

2014 ◽  
Vol 8 (3) ◽  
pp. 216-221
Author(s):  
Joonseok Ok ◽  
Seong-Joo Kang
Keyword(s):  
Phase Change ◽  
Temperature Change ◽  
Thermal Image ◽  
Thermal Image Camera ◽  
Image Camera

Electrical Performance of Zinc Oxide Surge Arresters in 22 kV Distribution System Using Thermal Image Camera

2014 ◽  
Vol 931-932 ◽  
pp. 857-861
Author(s):  
Wichet Thipprasert
Keyword(s):  
Zinc Oxide ◽  
Leakage Current ◽  
Distribution System ◽  
Reducing Power ◽  
Thermal Image ◽  
Electrical Performance ◽  
Surge Arresters ◽  
Thermal Image Camera ◽  
Long Time ◽  
Image Camera

Zinc Oxide (ZnO) surge arresters (SAs) experience thermal runaway when the temperature exceeds the acceptable limit. This phenomenon is associated with the increase in resistive leakage current due to degradation. This paper presents the electrical performance of ZnO SAs in 22 kV distribution system using thermal image camera under the power frequency AC operating voltages. When ZnO surge arresters are installation takes a long time in distribution system over than 5 years. For the experimental study, as ZnO installation takes a long time over than 6 years the leakage current is 63.9 mA, temperature difference were measured over a period of time over than 14 degree Celsius. This data will be useful as a guideline for solving problems and reducing power loss from leakage current. Moreover, it will be useful in predicting lifetime of ZnO SAs.

Comparison of Stratification in a Water Tank and a PCM-Water Tank

2007 ◽  
Author(s):  
A. Castell ◽  
C. Sole´ ◽  
M. Medrano ◽  
M. Nogue´s ◽  
L. F. Cabeza
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Temperature Change ◽  
High Energy ◽  
Hot Water ◽  
The Other ◽  
High Energy Density ◽  
Water Tank ◽  
Charging And Discharging Processes ◽  
Change Material

Most of the storage systems available on the market use water as storage medium. Enhancing the storage performance is necessary to increase the performance of most systems. The stratification phenomenon is employed to improve the efficiency of storage tanks. Heat at an intermediate temperature, not high enough to heat up the top layer, can still be used to heat the lower, colder layers. There are a lot of parameters to study the stratification in a water tank such as the Mix Number and the Richardson Number among others. The idea studied here was to use these stratification parameters to compare two tanks with the same dimensions during charging and discharging processes. One of them is a traditional water tank and the other is a PCM-water (a water tank with a Phase Change Material). A PCM is good because it has high energy density if there is a small temperature change, since then the latent heat is much larger than the sensible heat. On the other hand, the temperature change in the top layer of a hot water store with stratification is usually small as it is held as close as possible at or above the temperature for usage. In the system studied the Phase Change Material is placed at the top of the tank, therefore the advantages of the stratification still remain. The aim of this work is to demonstrate that the use of PCM in the upper part of a water tank holds or improves the benefit of the stratification phenomenon.

Numerical Prediction of Local Temperature and Current Density in a PEM Fuel Cell

2000 ◽  
Author(s):  
S. Shimpalee ◽  
S. Dutta ◽  
J. W. Van Zee
Keyword(s):  
Fuel Cell ◽  
Phase Change ◽  
Temperature Change ◽  
Heat Generation ◽  
Current Density ◽  
Pem Fuel Cells ◽  
Water Evaporation ◽  
Fuel Cell Performance ◽  
Local Current Density ◽  
Local Current

Abstract The heat generation inside polymer electrolyte membrane (PEM) fuel cells affects fuel cell performance significantly. A numerical model for three-dimensional single fuel cell is developed by including the energy equation and the phase change aspects. A control volume approach is used and source terms for species transport equations, heat generation, and phase change model are introduced to incorporate the coupled flow physics in commercial flow solvers. Details of local current density distribution and temperature profiles are obtained and predictions from this model are compared with previous conclusions. The results reveal that the water evaporation and condensation generated by temperature change in fuel cell control humidity of the membrane and vary the local current density value. Further, the temperature distributions are dependent on the amount of heat generation created by electrical losses and water phase change. The predictions also present that the performance of the fuel cell relies not only on the inlet humidity condition but also on the temperature change inside the fuel cell.

scholarly journals Phase change materials of fatty amine-modified silicate clays of nano layered structures

RSC Advances ◽  
2017 ◽  
Vol 7 (38) ◽  
pp. 23530-23534 ◽  
Author(s):  
Chien-Yi Liao ◽  
Jau-Yu Chiou ◽  
Jiang-Jen Lin
Keyword(s):  
Phase Change ◽  
Temperature Change ◽  
Phase Change Materials ◽  
Environmental Temperature ◽  
Layered Structures ◽  
Fatty Amine ◽  
Environmental Temperature Change

The ODA/MMT/paraffin was considered as PCM for absorbing and releasing heat according to the environmental temperature change.

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