The Experts below are selected from a list of 3624 Experts worldwide ranked by ideXlab platform
R U Halwatura - One of the best experts on this subject based on the ideXlab platform.
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Developing a durable thermally insulated Roof Slab system using bamboo insulation panels
International Journal of Energy and Environmental Engineering, 2019Co-Authors: Madujith Sagara Chandra, Kasun Nandapala, Gayan Priyadarshana, R U HalwaturaAbstract:Traditional Roofs can be effectively substituted by reinforced concrete Roof Slabs while gaining multiple advantages such as cyclonic resistance, possibility of future vertical extension and possibility of utilizing as an extra working space or a Rooftop garden. Further, it adds a significant economic benefit from land regaining. However, the immediate space beneath the Roof Slab results in thermal discomfort and hence the inventions related to insulated Roof Slab systems have been increased recently. Although the expected thermal comfort could be achieved, most of the inventions use artificial thermal insulation materials such as polystyrene. This paper introduces a novel Roof Slab insulation system which uses the natural material of transversely cut bamboo layer as the thermal insulator. The proposed system minimizes the negative environmental impacts induced by the use of artificial insulation materials. The optimum insulation layer thickness is found to be 25 mm, which has acquired a 53% peak heat gain reduction with a decrement factor of 0.61 and a 3-h time lag.
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Thermal performance of insulated Roof Slabs in tropical climates
Energy and Buildings, 2008Co-Authors: R U Halwatura, Mtr JayasingheAbstract:Reinforced concrete Roof Slabs can be an ideal alternative to traditional Roofs considering the better cyclone resistance that can be offered due to the self weight. However, the concrete Slabs do not perform satisfactorily in warm humid tropical climatic conditions and tend to act as heated bodies for the occupants in free running spaces. As a solution, a robust Roof Slab insulation system is proposed and its thermal performance was determined experimentally using small and large-scale models. With comfort models developed for the people acclimatized to tropical climatic conditions, it is shown that insulated Roof Slabs could provide acceptable indoor conditions while providing many valuable benefits such as cyclone resistance, regaining of land lost for the house and the possibility of creation of Roof top gardens.
Kasun Nandapala - One of the best experts on this subject based on the ideXlab platform.
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A study on the feasibility of a new Roof Slab insulation system in tropical climatic conditions
Energy and Buildings, 2020Co-Authors: Kasun Nandapala, Madujith Sagara Chandra, Rangika HalwaturaAbstract:Abstract A Roof Slab provides an extra robustness and a cyclonic resistance to the structures due to its self-weight. However, its performance in warm humid conditions is unsatisfactory because of the thermal discomfort in the immediate space beneath. Insulation has been recognized as an effective passive approach to address this issue. Thus, numerous insulation systems have been developed throughout the world. In this study, a system proven to be fruitful in tropical conditions was chosen and its negative aspects were recognized. Then, a new insulation system (a system with discontinuous supporting strips) was developed addressing the key drawbacks, and its thermal performance was compared with the prevailing systems. Prototype testing indicated that the negative effect of the supporting strips on the thermal performance of the system is negligible. Further, it was proven that this system achieves a heat gain reduction of more than 75%. An actual scale physical model proved that the system performs even better than a Calicut-tiled Roof with a timber ceiling in thermal aspects. Computer simulations deduced that on a sunny day in tropical conditions, about 20% of the peak cooling load reduction can be achieved by the system. In addition, it was found out that about 5% reduction of life cycle cost was achieved by this technique for a lifespan of 10–50 years. And also, it was proven that the insulated Slab performs better than an insulated Calicut tiled Roof in terms of Life Cycle Costing.
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Developing a durable thermally insulated Roof Slab system using bamboo insulation panels
International Journal of Energy and Environmental Engineering, 2019Co-Authors: Madujith Sagara Chandra, Kasun Nandapala, Gayan Priyadarshana, R U HalwaturaAbstract:Traditional Roofs can be effectively substituted by reinforced concrete Roof Slabs while gaining multiple advantages such as cyclonic resistance, possibility of future vertical extension and possibility of utilizing as an extra working space or a Rooftop garden. Further, it adds a significant economic benefit from land regaining. However, the immediate space beneath the Roof Slab results in thermal discomfort and hence the inventions related to insulated Roof Slab systems have been increased recently. Although the expected thermal comfort could be achieved, most of the inventions use artificial thermal insulation materials such as polystyrene. This paper introduces a novel Roof Slab insulation system which uses the natural material of transversely cut bamboo layer as the thermal insulator. The proposed system minimizes the negative environmental impacts induced by the use of artificial insulation materials. The optimum insulation layer thickness is found to be 25 mm, which has acquired a 53% peak heat gain reduction with a decrement factor of 0.61 and a 3-h time lag.
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Design of a durable Roof Slab insulation system for tropical climatic conditions
Cogent Engineering, 2016Co-Authors: Kasun Nandapala, Rangika HalwaturaAbstract:Flat Roof Slabs become popular day-by-day due to the advantages like cyclonic resistance, the possibility of future vertical extension, and the possibility of utilizing as an additional working space. However, a serious matter of concern is its thermal discomfort, for which air conditioning is used as the most common remedy. This has led to extensive use of energy, increasing the operational cost of the buildings, and contributing to global warming. Hence, the current trend is to go for passive techniques. Insulating Roof Slabs is identified as a better passive way to make buildings thermally comfortable. In this study, several existing Roof Slab insulation systems and their performances were investigated, and the most effective system for tropical climates was identified. Since that system had an issue in durability, a new system was developed with a discontinued-stripped supporting arrangement, which withstood a 4MT-point load. Further, it was proven by comparing literature that the newly designed syste...
Rangika Halwatura - One of the best experts on this subject based on the ideXlab platform.
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A study on the feasibility of a new Roof Slab insulation system in tropical climatic conditions
Energy and Buildings, 2020Co-Authors: Kasun Nandapala, Madujith Sagara Chandra, Rangika HalwaturaAbstract:Abstract A Roof Slab provides an extra robustness and a cyclonic resistance to the structures due to its self-weight. However, its performance in warm humid conditions is unsatisfactory because of the thermal discomfort in the immediate space beneath. Insulation has been recognized as an effective passive approach to address this issue. Thus, numerous insulation systems have been developed throughout the world. In this study, a system proven to be fruitful in tropical conditions was chosen and its negative aspects were recognized. Then, a new insulation system (a system with discontinuous supporting strips) was developed addressing the key drawbacks, and its thermal performance was compared with the prevailing systems. Prototype testing indicated that the negative effect of the supporting strips on the thermal performance of the system is negligible. Further, it was proven that this system achieves a heat gain reduction of more than 75%. An actual scale physical model proved that the system performs even better than a Calicut-tiled Roof with a timber ceiling in thermal aspects. Computer simulations deduced that on a sunny day in tropical conditions, about 20% of the peak cooling load reduction can be achieved by the system. In addition, it was found out that about 5% reduction of life cycle cost was achieved by this technique for a lifespan of 10–50 years. And also, it was proven that the insulated Slab performs better than an insulated Calicut tiled Roof in terms of Life Cycle Costing.
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Design of a durable Roof Slab insulation system for tropical climatic conditions
Cogent Engineering, 2016Co-Authors: Kasun Nandapala, Rangika HalwaturaAbstract:Flat Roof Slabs become popular day-by-day due to the advantages like cyclonic resistance, the possibility of future vertical extension, and the possibility of utilizing as an additional working space. However, a serious matter of concern is its thermal discomfort, for which air conditioning is used as the most common remedy. This has led to extensive use of energy, increasing the operational cost of the buildings, and contributing to global warming. Hence, the current trend is to go for passive techniques. Insulating Roof Slabs is identified as a better passive way to make buildings thermally comfortable. In this study, several existing Roof Slab insulation systems and their performances were investigated, and the most effective system for tropical climates was identified. Since that system had an issue in durability, a new system was developed with a discontinued-stripped supporting arrangement, which withstood a 4MT-point load. Further, it was proven by comparing literature that the newly designed syste...
P Chellapandi - One of the best experts on this subject based on the ideXlab platform.
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Experimental validation of thermal design of top shield for a pool type SFR
Nuclear Engineering and Design, 2016Co-Authors: Sriramachandra Aithal, V. Rajan Babu, V. Balasubramaniyan, K. Velusamy, P ChellapandiAbstract:Abstract An Integrated Top Shield Test Facility towards validation of thermal design of top shield for a pool type SFR has been conceived, constructed & commissioned. Detailed experiments were performed in this experimental facility having full-scale features. Steady state temperature distribution within the facility is measured for various heater plate temperatures in addition to simulating different operating states of the reactor. Following are the important observations (i) jet cooling system is effective in regulating the Roof Slab bottom plate temperature and thermal gradient across Roof Slab simulating normal operation of reactor, (ii) wire mesh insulation provided in Roof Slab-main vessel annulus is effective in obtaining gradual thermal gradient along main vessel top portion and inhibiting the setting up of cellular convection within annulus and (iii) cellular convection with four distinct convective cells sets in the annular gap between Roof Slab and small rotatable plug measuring ∼ϕ4 m in diameter & gap width varying from 16 mm to 30 mm. Repeatability of results is also ensured during all the above tests. The results presented in this paper is expected to provide reference data for validation of thermal hydraulic models in addition to serving as design validation of jet cooling system for pool type SFR.
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Structural design optimization of Roof Slab of a pool type sodium cooled fast reactor
Advances in Engineering Software, 2016Co-Authors: V. Prabhu Raja, V. Rajan Babu, M. Ramu, P. R. Thyla, Sriramachandra Aithal, P ChellapandiAbstract:Abstract The Roof Slab of the nuclear reactor supports all the components of the reactor. Roof Slab is essentially a box structure with top and bottom plates interconnected by vertical shells and radial stiffeners welded to them. The gap between the top and bottom plates is filled with concrete that provides biological and thermal shielding in the top axial direction of the reactor. The 500 MWe Prototype Fast Breeder Reactor (PFBR) is designed based on the Operating Basis Earthquake (OBE) and Safe Shutdown Earthquake (SSE) which are categorized under level A and level D loadings respectively. The primary objective of this work is to optimize the design of the Roof Slab and to predict and ascertain the structural integrity of the optimized Roof Slab under static, harmonic and seismic loading conditions. Regression models for critical design parameters are developed and are used in the optimization algorithm.
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Design and development of thick plate concept for rotatable plugs and technology development for future Indian FBR
Nuclear Engineering and Design, 2012Co-Authors: Abhishek Mitra, V. Rajan Babu, P. Puthiyavinayagam, N. Vijayan Varier, Manas Ghosh, Hemal Desai, P Chellapandi, S.c. ChetalAbstract:Abstract Prototype fast breeder reactor (PFBR) is at an advanced stage of construction in Kalpakkam, India. Top shield (consisting of Roof Slab and rotatable plugs) of PFBR is of box type construction. It is a Class-1 component being a part of the primary leak-tight boundary of the reactor assembly. In the future commercial fast breeder reactor (CFBR), it is planned to adopt thick plate concept for rotatable plugs. The thickness of the plates required for the rotatable plugs of CFBR was arrived at based on finite element analysis considering mechanical and thermal loads. The main advantage of using thick plate for the rotatable plugs is that it eliminates the possibility of lamellar tearing which exists in the box type construction. The successful realisation of this concept necessitates the indigenous development of thick plate narrow gap welding technology. Hence a technology development programme for realising 800 mm thick narrow gap welds using submerged arc welding process was undertaken. Three numbers of welded joints were made to demonstrate the successful development of thick plate narrow gap welding technology. Repair procedure for the weld was also established. Non-destructive examination and destructive testing were carried out and the results were analysed critically. The attenuation of ultrasonic wave in narrow gap weld as compared to that in the base metal was examined. This paper discusses the need and conceptual design of thick plate concept for rotatable plugs in CFBR, the approach adopted for technology development of thick plate narrow gap welding and the salient experiences gained during the developmental project. Recommendations are made regarding the RCC-MR code rules for the non-destructive volumetric examination of welds of thick carbon steel plates.
Mtr Jayasinghe - One of the best experts on this subject based on the ideXlab platform.
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Thermal performance of insulated Roof Slabs in tropical climates
Energy and Buildings, 2008Co-Authors: R U Halwatura, Mtr JayasingheAbstract:Reinforced concrete Roof Slabs can be an ideal alternative to traditional Roofs considering the better cyclone resistance that can be offered due to the self weight. However, the concrete Slabs do not perform satisfactorily in warm humid tropical climatic conditions and tend to act as heated bodies for the occupants in free running spaces. As a solution, a robust Roof Slab insulation system is proposed and its thermal performance was determined experimentally using small and large-scale models. With comfort models developed for the people acclimatized to tropical climatic conditions, it is shown that insulated Roof Slabs could provide acceptable indoor conditions while providing many valuable benefits such as cyclone resistance, regaining of land lost for the house and the possibility of creation of Roof top gardens.
