Analysis of the performance of an integrated multistage helical coil heat transfer device and passive cooling windcatcher for buildings in hot climates

2021 ◽  
pp. 103899
Author(s):  
Kate Pelletier ◽  
John Calautit
2016 ◽  
Vol 37 (4) ◽  
pp. 137-159 ◽  
Author(s):  
Rafał Andrzejczyk ◽  
Tomasz Muszyński

Abstract The shell and coil heat exchangers are commonly used in heating, ventilation, nuclear industry, process plant, heat recovery and air conditioning systems. This type of recuperators benefits from simple construction, the low value of pressure drops and high heat transfer. In helical coil, centrifugal force is acting on the moving fluid due to the curvature of the tube results in the development. It has been long recognized that the heat transfer in the helical tube is much better than in the straight ones because of the occurrence of secondary flow in planes normal to the main flow inside the helical structure. Helical tubes show good performance in heat transfer enhancement, while the uniform curvature of spiral structure is inconvenient in pipe installation in heat exchangers. Authors have presented their own construction of shell and tube heat exchanger with intensified heat transfer. The purpose of this article is to assess the influence of the surface modification over the performance coefficient and effectiveness. The experiments have been performed for the steady-state heat transfer. Experimental data points were gathered for both laminar and turbulent flow, both for co current- and countercurrent flow arrangement. To find optimal heat transfer intensification on the shell-side authors applied the number of transfer units analysis.


Author(s):  
Anthony Edward Morris ◽  
C. S. Wei ◽  
Runar Unnthorsson ◽  
Robert Dell

Since 2006, The Center for Innovation and Applied Technology (CIAT) at Cooper Union for the Advancement of Science and Art has been developing a system to use thermal pollution to heat the growth medium of green roofs. CIAT is researching various apparatus and techniques, including shell-and-tube and shell-and-coil heat exchangers, to improve its heated ground agricultural projects. There are limited recorded observations on shell-and-coil heat exchangers; therefore a laboratory work station was created of interchangeable components to test the efficiency of a variety of coil designs. This paper discusses the data collected on temperature, pressure, and flow rates for a straight tube and two different helical coils. The analysis of this data indicates the superiority of a helical coil design when compared to a straight tube design with respect to both rating and heat transfer rate. The same data analysis has lead to preliminary observations on how the contour properties of a helical coil influence the heat transfer rate through a coil. The authors intend to further this helical coil research to develop a useful mathematical model for determining efficient designs for shell-and-coil heat exchangers.


Author(s):  
A.A. Aleksandrov ◽  
I.V. Barmin ◽  
S.K. Pavlov ◽  
V.V. Chugunkov

The paper focuses on hydrocarbon fuel cooling in launch vehicles, specifically considering experimental technique and results obtained during investigation of one of the primary heat exchanger parameters, that is, heat transfer coefficient of the heat exchanger surface. We present a model of efficient hydrocarbon fuel cooling by means of intensifying heat transfer on the external heat exchanger surface due to nitrogen sparging causing active motion in the liquid heat carrier. We obtained quantitative data regarding heat transfer on the external surface of a helical-coil heat exchanger located in a two-phase medium consisting of antifreeze and nitrogen, in the temperature range of 243--293 K. We derived a similarity equation for calculating heat transfer coefficient on the external heat exchanger surface, which is required to determine the heat exchanger surface area and to compute heat transfer from hydrocarbon fuel to the two-phase medium consisting of antifreeze and nitroge.


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