Sizing and selection of heat exchanger at defined saving–investment ratio

2011 ◽  
Vol 31 (5) ◽  
pp. 727-734 ◽  
Author(s):  
Özden Ağra
Keyword(s):  
Heat Exchanger ◽  
Investment Ratio ◽  
Selection Of

Multipass Plate Heat Exchangers—Effectiveness-NTU Results and Guidelines for Selecting Pass Arrangements

1989 ◽  
Vol 111 (2) ◽  
pp. 300-313 ◽  
Author(s):  
S. G. Kandlikar ◽  
R. K. Shah
Keyword(s):  
Heat Capacity ◽  
Heat Exchanger ◽  
Finite Difference Method ◽  
Heat Exchangers ◽  
Rate Ratio ◽  
Plate Heat Exchanger ◽  
Tabular Form ◽  
Plate Heat ◽  
Number Of Passes ◽  
Selection Of

Plate heat exchangers are classified on the basis of number of passes on each side and the flow arrangement in each channel, taking into account the end plate effects. This results in four configurations each for the 1–1 (1 Pass–1 Pass), 2–1, 2–2, 3–3, 4–1, 4–2, and 4–4 arrangements, and six configurations for the 3–1 arrangement. These arrangements are analyzed using the Gauss–Seidel iterative finite difference method; the plate arrangement that yields the highest effectiveness in each pass configuration is identified. Comprehensive results are presented in tabular form for the temperature effectiveness P1 and log-mean temperature difference correction factor F as functions of the number of transfer units NTU1, the heat capacity rate ratio R1, and the total number of thermal plates. On the basis of these results, specific guidelines are outlined for the selection of appropriate plate heat exchanger configurations.

scholarly journals Basic design of a cooling system for nylon 6, 6 process

2018 ◽  
Vol 7 (3) ◽  
pp. 977
Author(s):  
Karthik Silaipillayarputhur Ph. D ◽  
Nasser Al Mulhim ◽  
Abdullah Al Mulhim ◽  
Mohammed Arfaj ◽  
Ahmed Al Naim
Keyword(s):  
Heat Exchanger ◽  
Rate Ratio ◽  
Cooling System ◽  
Ambient Air ◽  
Nylon 6 ◽  
Polymer Fibers ◽  
Basic Design ◽  
Quenching Process ◽  
Pre Treatment ◽  
Selection Of

The project concentrates on the basic design of a cooling system for rapidly cooling nylon 6, 6 polymer fibers using cold air. The ambient air after pre-treatment in the air-washer is available at 72°F all year round. Based on the company’s throughput, it is required to supply (quench) air at 58°F. Nylon 6, 6 polymer after thorough polymerization is distributed through 16 quench cabinets and each quench cabinet requires approximately 530 ft3/min (cubic feet per minute, CFM) of air. The project concentrates on the basic design of a cooling system wherein air at the required mass flow rate is supplied at 58°F for the quenching process. A basic design of the refrigeration cycle and heat exchangers were considered in this work. In the development of the basic design for heat exchanger, performance charts were developed. Performance charts describe the performance of the heat exchanger in terms of fundamental dimensionless parameters. Using performance charts it was clearly seen that increasing the number of transfer units (NTU) doesn’t necessarily increase the rate of heat transfer. Increasing the NTU beyond an optimum value is pointless and increases the capital cost of the heat exchanger. The preliminary design involves selection of appropriate NTU and capacity rate ratio for the heat exchanger. From the capacity rate ratio and NTU, it is fairly straight forward to extrapolate the detailed design for the heat exchanger. A cooling system model was developed for the design process and for the simulation of the cooling system.  

Exergy Study of Fouling Factors in Heat Exchanger Networks

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Zunlong Jin ◽  
Qiwu Dong ◽  
Minshan Liu
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Objective Function ◽  
Capital Cost ◽  
Numerical Results ◽  
Heat Transfer Area ◽  
Heat Exchanger Networks ◽  
Exergy Consumption ◽  
Exergoeconomic Analysis ◽  
Selection Of

Selection of fouling factors is somewhat arbitrary in heat exchanger networks (HENs) synthesis. Fouling factors were reconsidered in this article for heat exchanger networks design. An objective function based on exergoeconomic analysis was introduced to assess optimal less conservative fouling factors. The objective took account of exergy consumption expense and heat exchanger capital cost at the same time. The exergy consumption of heat transfer in HENs was calculated using subsection integral on balanced composite curves. The proposed method was applied to an industrial case. Numerical results indicated that the optimal less conservative fouling factors were 80% of the original values and the heat transfer area of the system saved 350 m2 compared with root design. So it is necessary to reconsider the values of fouling factors for HENs design and that exergoeconomic analysis is useful in determining the optimal less conservative fouling factors.

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