Case study: Limited charge shell and tube ammonia spray evaporator with enhanced tubes

2006 ◽  
Vol 26 (11-12) ◽  
pp. 1334-1338 ◽  
Author(s):  
Z.H. Ayub ◽  
M.-C. Chyu ◽  
A.H. Ayub
Sugar Tech ◽  
2021 ◽  
Author(s):  
Thalyne de Almeida Ferreira Rocha ◽  
Altair Marques da Silva

2020 ◽  
Vol 20 (2020) ◽  
pp. 299-300
Author(s):  
Wagner Henrique Saldanha ◽  
Gustavo de Oliveira Wardil ◽  
Marcelo de Deus Oliveira

Author(s):  
Austin L. Nash ◽  
Neera Jain

Abstract We present a new methodology for designing a heat exchanger that explicitly considers both static and transient performance characteristics. The proposed approach leverages 1) a highly detailed, albeit static model that captures the complex nonlinear relationship between heat exchanger geometry and heat transfer coefficients, and 2) a reduced-order dynamic model of the heat exchanger that approximates the geometry detailed in the static model. In order to optimize the component design for both static and transient performance metrics, pole locations of the corresponding linearized model are penalized in the cost function of the proposed optimization algorithm in order to move dominant poles further into the left half complex plane. Through a simulated case study for a shell and tube heat exchanger, we demonstrate how the proposed algorithm exploits the trade off between static design metrics, including mass and footprint, and the rate at which heat is removed from the primary fluid.


2003 ◽  
Author(s):  
Wei Li

This paper addresses fouling in a family of seven 15.54 mm I.D. copper, helically ribbed tubes, which have different ridge heights, helix angles, and number of ridge starts. A series of semi-theoretical linear fouling correlations as a function of the product of area indexes and efficiency indexes for long term combined precipitation and particulate fouling (PPF) in cooling tower systems and a series of semi-theoretical linear fouling correlations as a function of the efficiency indexes for particulate fouling were developed. The correlations can be directly used to assess the fouling potential of enhanced tubes in actual cooling water situations.


2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Wen-Tao Ji ◽  
Chuang-Yao Zhao ◽  
Jessica Lofton ◽  
Zeng-Yao Li ◽  
Ding-Cai Zhang ◽  
...  

In this work, the condensation of refrigerants on a single, high-density, low-fin tube and full-sized shell and tube condensers were investigated experimentally. The low-fin tube had an external fin density of 56 fins per inch (fpi) and fin height 1.023 mm. Another three-dimensional (3D) finned tube was also tested for comparison. The condensing heat transfer coefficient of the refrigerant R134a was first investigated outside a single horizontal tube at saturation temperature of 40 °C. The overall heat transfer coefficients of the two tubes were similar in magnitude. The condensing heat transfer coefficient of the low-fin tube was 16.3–25.2% higher than that of 3D enhanced tube. The experiments of the two condensers mounted with low-fin and 3D enhanced tubes were then conducted in centrifugal and screw chiller test rigs. It was found that chillers with the two different condensers generally had the same refrigeration capacity under the same experiment conditions. The refrigeration capacity of the screw chiller was smaller. It had fewer tube rows and elicited fewer inundation effects owing to the falling condensate. The heat transfer coefficients of the condensers with R134a in centrifugal chillers equipped with high-density low-finned tubes were higher than those in the screw chillers. The total number of tubes for low-fin tube condensers, in the two chillers, was reduced by approximately 15% compared with the use of domestic advanced condensers equipped with the 3D enhanced tubes.


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