scholarly journals A Brief Review on Radiant Cooling Panel with Different Chilled Water Pipe Configurations

Author(s):  
Mohammad Hakim Mohd. Radzai ◽  
Chin Wai Lim ◽  
Chong Tak Yaw ◽  
Siaw Paw Koh ◽  
Nur Amirani Ahmad ◽  
...  

Radiant cooling systems are commonly applied in commercial applications because of their energy-saving potential. This potential can be further enhanced by evaluating the cooling performance of the radiant cooling panel in terms of flow configurations. Although studies have been conducted on the flow configurations of the radiant cooling panel, the most suitable flow configurations have yet to be determined. The conventional serpentine flow configuration does not bring out the best cooling performance of the radiant cooling panel, therefore different flow configurations are still needed to be explored. This study conducted a quick literature review on the different radiant cooling systems as well as radiant cooling panel with different chilled water pipe configurations. The objective of this review is to provide a brief comparison of the performance of radiant cooling panel with different chilled water pipe configurations and to suggest further studies for the system development. The cooling characteristics and heat transfer of the panel are investigated by using numerical study. A comparison between the designs of flow configurations is presented. In all of the cases, the plate area and flow volume are fixed. Based on the findings obtained, applying a different chilled water pipe configuration on the radiant cooling panel will affect the flow uniformity and also the temperature distribution uniformity. An optimized flow configurations for the radiant cooling panel is important for enhancing the overall efficiency of the system.

2017 ◽  
Vol 80 ◽  
pp. 238-251 ◽  
Author(s):  
Ramy H. Mohammed ◽  
Osama Mesalhy ◽  
Mohamed L. Elsayed ◽  
Louis C. Chow

Author(s):  
Bingran Li ◽  
Cunliang Liu ◽  
Lin Ye ◽  
Huiren Zhu ◽  
Fan Zhang

Abstract To investigate the application of ribbed cross-flow coolant channels with film hole effusion and the effects of the internal cooling configuration on film cooling, experimental and numerical studies are conducted on the effect of the relative position of the film holes and different orientation ribs on the film cooling performance. Three cases of the relative position of the film holes and different orientation ribs (post-rib, centered, and pre-rib) in two ribbed cross-flow channels (135° and 45° orientation ribs) are investigated. The film cooling performances are measured under three blowing ratios by the transient liquid crystal measurement technique. A RANS simulation with the realizable k-ε turbulence model and enhanced wall treatment is performed. The results show that the cooling effectiveness and the downstream heat transfer coefficient for the 135° rib are basically the same in the three position cases, and the differences between the local effectiveness average values for the three are no more than 0.04. The differences between the heat transfer coefficients are no more than 0.1. The “pre-rib” and “centered” cases are studied for the 45° rib, and the position of the structures has little effect on the film cooling performance. In the different position cases, the outlet velocity distribution of the film holes, the jet pattern and the discharge coefficient are consistent with the variation in the cross flow. The related research previously published by the authors showed that the inclination of the ribs with respect to the holes affects the film cooling performance. This study reveals that the relative positions of the ribs and holes have little effect on the film cooling performance. This paper expands and improves the study of the effect of the internal cooling configuration on film cooling and makes a significant contribution to the design and industrial application of the internal cooling channel of a turbine blade.


Author(s):  
Siavash Khajehhasani ◽  
Bassam Jubran

A numerical study on the effects of sister holes locations on film cooling performance is presented. This includes the change of the location of the individual discrete sister holes in the streamwise and spanwise directions, where each one of these directions includes 9 different locations, The simulations are performed using three-dimensional Reynolds-Averaged Navier Stokes analysis with the realizable k–ε model combined with the standard wall function. The variation of the sister holes in the streamwise direction provides similar film cooling performance as the base case for both blowing ratios of 0.5 and 1. On the other hand, the spanwise variation of the sister holes’ location has a more prominent effect on the effectiveness. In some cases, as a result of the anti-vortices generated from the sister holes and the repositioning of the sister holes in the spanwise direction, the jet lift-off effect notably decreases and more volume of coolant is distributed in the spanwise direction.


1993 ◽  
Vol 115 (1) ◽  
pp. 1-8 ◽  
Author(s):  
D. G. Waugaman ◽  
A. Kini ◽  
C. F. Kettleborough

This paper describes recent published design advances that have been made in desiccant cooling systems. In desiccant cooling cycles, the desiccant reduces the humidity of the air by removing moisture from the air. Then the temperature is reduced by other components such as heat exchangers, evaporative coolers, or conventional cooling coils. The main advantage that desiccant cooling systems offer is the capability of using low-grade thermal energy. Desiccant cooling systems for residential and commercial applications are now being used to reduce energy-operating costs. However, the initial costs are comparatively high. The focus of research for the past decade has been to develop desiccant systems with a high coefficient of performance. Recent studies have emphasized computer modeling and hybrid systems that combine desiccant dehumidifiers with conventional systems.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2574 ◽  
Author(s):  
Ramadas Narayanan ◽  
Edward Halawa ◽  
Sanjeev Jain

Air conditioning accounts for up to 50% of energy use in buildings. Increased air-conditioning-system installations not only increase total energy consumption but also raise peak load demand. Desiccant evaporative cooling systems use low-grade thermal energy, such as solar energy and waste heat, instead of electricity to provide thermal comfort. This system can potentially lead to significant energy saving, reduction in carbon emissions, and it has a low dew-point operation and large capacity range. Their light weight, simplicity of design, and close-to-atmospheric operation make them easy to maintain. This paper evaluates the applicability of this technology to the climatic conditions of Brisbane, Queensland, Australia, specifically for the residential sector. Given the subtropical climate of Brisbane, where humidity levels are not excessively high during cooling periods, the numerical study shows that such a system can be a potential alternative to conventional compression-based air-conditioning systems. Nevertheless, the installation of such a system in Brisbane’s climate zone requires careful design, proper selection of components, and a cheap heat source for regeneration. The paper also discusses the economy-cycle options for this system in such a climate and compares its effectiveness to natural ventilation.


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