More Non-Dimensional Models for Simple Heat Exchangers

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More Non-Dimensional Models for Simple Heat
Exchangers

• P M V Subbarao
• Professor
• Mechanical Engineering Department
• I I T Delhi

Different Shape Functions for Compact Sobolev
Devices ..
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e-NTU Models for Simple Counter Flow HXs
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e-NTU Models for Simple Parallel Flow Heat Ex
Thi
The
Tce
Tci
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e- NTU Curves Counter Vs parallel flow
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Limiting Cases
Two limiting cases of interest R 1 and R 0
For R 1 above equation is indeterminate. Apply
L Hospitals Rule .
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L Hospitals Rule
Consider a function
If there exist a real value c such that
has a finite value, then
If
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Two limiting cases of interest R 1
Counter flow Heat exchanger
Parallel flow Heat exchanger
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HX with Equal Capacity Fluids
e
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Condensing/Evaporative HXs
The limiting case of interest R 0.
Counter flow Heat exchanger
Parallel flow Heat exchanger
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Condensing/Evaporative HXs
e
NTU
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General Models for Simple Heat Exchangers
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System of Equations
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Non-dimensional Model - II
Counter Flow
Parallel Flow
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Generalized Performance Charts for HX.
R
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More Mathematics for Industrial Design
A single pass counter flow heat exchanger, with
CcltCh.
Thermal Capacity Ratio
Temperature Effectiveness
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A single pass counter flow heat exchanger, with
CcltCh.
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Design for Safety of A HX