Experimental study of the thermal performance of an extensive green roof on sunny summer days

The current study experimentally investigates the heat transfer augmentation on the novel axial corrugated heat exchanger tube in which the spring tape is introduced. Air (Pr = 0.707) is used as a working fluid. In order to augment the thermohydraulic performance, a corrugated tube with inserts is offered. The experimental study is further extended by varying the important parameters like spring ratio (y = 1.5, 2.0, 2.5) and Reynolds number (Re = 10 000–52 000). The angular pitch between the two neighboring corrugations and the angle of the corrugation is kept constant through the experiments at β = 1200 and α = 600 respectively, while two different corrugations heights (h) are analyzed. While increasing the corrugation height and decreasing the spring ratio, the impact of the swirling effect improves the thermal performance of the system. The maximum thermal performance is obtained when the corrugation height is h = 0.2 and spring ratio y = 1.5. Eventually, correlations for predicting friction factor (f) and Nusselt number (Nu) are developed.

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THERMAL PERFORMANCE OF CLOSED LOOP PULSATING HEAT PIPE: AN EXPERIMENTAL STUDY WITH VISUALIZATION

Heat Pipe Science and Technology An International Journal ◽

10.1615/heatpipescietech.v5.i1-4.500 ◽

2014 ◽

Vol 5 (1-4) ◽

pp. 441-448

Author(s):

Pramod R. Pachghare ◽

Ashish M. Mahalle

Keyword(s):

Experimental Study ◽

Heat Pipe ◽

Thermal Performance ◽

Closed Loop ◽

Pulsating Heat Pipe

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THE GREEN ROOF THERMAL PERFORMANCE EVALUATION IN COMPARISON TO ASBESTOS CEMENT TILES APPLIED TO LIGHT STEEL FRAME BRAZILIAN BUILDINGS

International Journal of Architectural Research Archnet-IJAR ◽

10.26687/archnet-ijar.v12i3.1709 ◽

2018 ◽

Vol 12 (3) ◽

pp. 288

Author(s):

Angélica Felicidade Guião Marcato Costa ◽

João Alexandre Paschoalin Filho ◽

Tatiana Tucunduva Philipi Cortese ◽

Brenda Chaves Coelho Leite

Keyword(s):

Performance Evaluation ◽

Relative Humidity ◽

Heat Flow ◽

Thermal Performance ◽

Green Roof ◽

Steel Frame ◽

Internal Temperature ◽

Green Cover ◽

Asbestos Cement ◽

Data Representative

This research aimed at comparing the thermal performance provided in experimental modules, one of which was performed with conventional cover, made of asbestos cement tiles; an another with green cover. The structure of the studied modules was executed using Light Steel Frame technique. As an experimental research, modules were built in a wide place, without the interference of shading. Instruments were installed in the inner part of the modules to measure the following data: air temperature, relative humidity. From the collected data, representative episodes have been chosen for the studies that aimed to compare the comfort provided by both modules, built with different roofs. As result, it was verified that the module with green roof had better performance than the module covered with asbestos cement tile in all selected episodes. The module covered with green roof maintained lower internal temperature variation throughout the days, indicating that the green roof has characteristic thermal insulation, reducing the heat flow from the roof.

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