Performance Deterioration in High Effectiveness Heat Exchangers Due to Axial Heat Conduction Effects

Kroeger, P.G.

doi:10.1007/978-1-4757-0489-1_38

Cited by 62 publications

(15 citation statements)

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“…The exchanger ineffectiveness (1 À e) of Equation (15) is shown in [3,6]. For 0.8 C * 1, the following correlation for e is obtained [10]:…”

Section: Longitudinal Wall Heat Conductionmentioning

confidence: 99%

“…The influence of longitudinal conduction is reported in the heat exchanger literature in terms of the e-NTU method for single-pass counterflow and single-pass crossflow exchangers with both fluids unmixed. For the single-pass counterflow exchanger, the exchanger effectiveness, including the effect of longitudinal conduction, for C * ¼ 1 and 0.1 h o hA 10 is [10]:…”

Section: Longitudinal Wall Heat Conductionmentioning

confidence: 99%

“…The specific heat of each fluid is constant throughout the exchanger so that the heat capacity rate on each side is treated as constant. Note that the other fluid properties are not involved directly in the energy balance and rate equations, but are treated as constant 10. For an extended surface exchanger, the overall extended surface efficiency is considered uniform and constant 11.…”

mentioning

confidence: 99%

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Heat Exchangers, 2. Heat Transfer for Heat Exchanger Design

Shah

Mueller²,

Sekulić

2015

Ullmann's Encyclopedia of Industrial Chemistry

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The article contains sections titled: 1. Basic Heat‐Transfer and Pressure‐Drop Analysis 1.1. Basic Equations and Definitions of Heat‐Transfer Analysis 1.1.1. Fundamental Concepts 1.1.2. Temperature Distributions and Heat Exchanger Effectiveness 1.2. Dimensionless Methods for Exchanger Heat‐Transfer Analysis 1.3. Extensions of the Basic Heat‐Transfer Theory 1.3.1. Longitudinal Wall Heat Conduction 1.3.2. Variable Overall Heat‐Transfer Coefficients 1.4. Exchanger Pressure‐Drop Analysis 1.4.1. Plate – Fin Exchangers 1.4.2. Tube – Fin Exchangers 1.4.3. Regenerators 1.4.4. Plate Heat Exchangers 2. Single‐Phase Heat‐Transfer and Pressure‐Drop Correlations 2.1. Basic Concepts and Dimensionless Groups 2.2. Theoretical Solutions and Correlations for Simple Geometries 2.2.1. Fully Developed Flows 2.2.2. Hydrodynamically Developing Flows 2.2.3. Thermally Developing Flows 2.2.4. Simultaneously Developing Flows 2.3. Empirical Correlations for Complex Geometries 2.3.1. Tubular Exchangers 2.3.2. Plate Exchangers 2.3.3. Extended Surface Exchangers 3. Two‐Phase Heat‐Transfer and Pressure‐Drop Correlations 3.1. Flow Patterns 3.2. Two‐Phase Pressure‐Drop Correlations 3.2.1. Intube Pressure Drop 3.2.2. Shellside (Tube Bundle) Pressure Drop 3.2.3. Other Geometries 3.3. Heat‐Transfer Correlations for Condensation 3.3.1. Condensation Inside a Horizontal Tube 3.3.2. Condensation Inside a Vertical Tube 3.3.3. Condensation Outside Horizontal Tube Bundles 3.3.4. Condensation over Finned Tubes 3.3.5. Condensation Outside Vertical Tube Bundles 3.3.6. Condensation of Mixtures 3.4. Heat‐Transfer Correlations for Boiling and Evaporation 3.4.1. Intube Forced Convective Boiling 3.4.2. Intube Critical Heat Flux 3.4.3. Shellside Forced Convective Boiling 3.4.4. Shellside Critical Heat Flux 4. Thermal Design for Single‐Phase Heat Exchangers 4.1. Introduction 4.2. Shell‐and‐Tube Exchangers 4.2.1. Segmental Baffles 4.2.1.1. Shellside Heat Transfer 4.2.1.2. Shellside Pressure Drop 4.2.2. Disk‐and‐Doughnut Baffles 4.2.3. Rod Baffles 4.2.4. Design Procedure 4.3. Compact Heat Exchangers 4.3.1. The Rating Problem 4.3.2. The Sizing Problem 4.3.3. Micro‐Channel Heat Exchangers

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“…The exchanger ineffectiveness (1 À e) of Equation (15) is shown in [3,6]. For 0.8 C * 1, the following correlation for e is obtained [10]:…”

Section: Longitudinal Wall Heat Conductionmentioning

confidence: 99%

Section: Longitudinal Wall Heat Conductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Heat Exchangers, 2. Heat Transfer for Heat Exchanger Design

Shah

Mueller²,

Sekulić

2015

Ullmann's Encyclopedia of Industrial Chemistry

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“…From the energy balance between fluid streams and heat exchanger wall, equations that govern the temperature distributions and effectiveness can be solved analytically or numerically [16,17]. In the present study, we adopted the solutions by Kroeger [16] in which the effectiveness for a counterflow heat exchanger is given as Balanced flow (C R = 1):…”

Section: Size Effects Of Miniature Refrigeration and Liquefaction Systemmentioning

confidence: 99%

Size Effects of Miniature Refrigeration and Liquefaction System

Yang¹,

Chung²

2006

Nanoscale and Microscale Thermophysical Engineering

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This article examines the size effects on the performance of miniature refrigerators and liquefiers operated by the Linde cycle. The system sizes are cased into a function of the compressor characteristic length and the heat exchanger length while several cycle operation parameters are held constant. Simplified models of a Hampson-type counterflow heat exchanger and a reciprocating-type compressor were considered in the present analysis.For both the refrigerator and the liquefier, it was found that only for certain ranges of the compressor size is the system able to produce a heat exchanger effectiveness greater than the required minimum value. It was also found that there exists an optimal compressor size for obtaining maximum heat exchanger effectiveness, cooling effect, mass fraction of liquefied product, and coefficient of performance. For the refrigerator, the optimal compressor size for obtaining the maximum heat exchanger effectiveness is different from that for obtaining the maximum cooling effects because of the mass flow rate effect. For the liquefier, the optimal compressor sizes for obtaining the maximum heat exchanger effectiveness, mass fraction of liquefied gas product, and FOM are approximately the same.When the Claude cycle is employed, it is found that it theoretically offers a more satisfactory performance than the Linde cycle in the small size range. The FOM of a mesoscale system with the Claude cycle can reach the range of 20 to 23% with the liquid product temperature ranging from 65 to 90 K.

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“…Analytical formulae are given in all text and reference books on heat exchangers [1][2][3][4][5][6][7][8][9] for design of two-stream units. Non-uniform heat transfer coefficient, property variations and the presence of secondary effects like longitudinal conduction and axial dispersion makes the analysis somewhat complex; but can be easily tackled using numerical approach [10,11]. On the other hand the design and simulation of multistream plate fin heat exchangers are markedly different from those of two-fluid exchangers.…”

Section: Introductionmentioning

confidence: 99%