FCorrectionFactor¶

class pychemengg.heattransfer.heatexchangers.FCorrectionFactor[source]¶

Bases: object

Contains functions to compute ‘F’ correction factor for LMTD for heat exchangers.

Parameters

`None_required`‘None’: This class takes no parameters for instance creation.

Examples

First import the module heatexchangers.

>>> from pychemengg.heattransfer import heatexchangers as hx 
>>> hx1 = hx.FCorrectionFactor
# This will assign the class 'FCorrectionFactor' to the
# variable 'hx1'.
# Methods of the class 'FCorrectionFactor' can then be called like so :-
# hx1.methodname(kwarg1=x, ... etc)

Attributes

`None_required`‘None’: This class does not expose any instance attributes.

__init__(*args, **kwargs)¶

Methods

`__init__`(args, *kwargs)
`calc_R_P`([T_tubein, T_tubeout, T_shellin, …])	To find ‘R’ and ‘P’ parameters needed to compute ‘F’ correction factors.
`oneshell2ntubepasses`([T_tubein, T_tubeout, …])	To find ‘F’ correction factor for LMTD.
`singlepass_crossflow_bothmixed`([T_tubein, …])	To find ‘F’ correction factor for LMTD.
`singlepass_crossflow_bothunmixed`([T_tubein, …])	To find ‘F’ correction factor for LMTD.
`singlepass_crossflow_oneunmixed`([T_tubein, …])	To find ‘F’ correction factor for LMTD.
`twoshell4ntubepasses`([T_tubein, T_tubeout, …])	To find ‘F’ correction factor for LMTD.

calc_R_P(T_tubein=None, T_tubeout=None, T_shellin=None, T_shellout=None)[source]¶

To find ‘R’ and ‘P’ parameters needed to compute ‘F’ correction factors. Could be useful to manually look up tables of F correction factors in textbooks.

Parameters

T_tubeinint or float: Temperature of tube side (or cold) fluid at inlet.
T_tubeoutint or float: Temperature of tube side (or cold) fluid at outlet.
T_shellinint or float: Temperature of shell side (or hot) fluid at inlet.
T_shelloutint or float: Temperature of shell side (or hot) fluid at outlet.

Returns

tuple containg R-parameter and P-parameter :: (R-parameter : int or float, P-parameter : int or float)

Notes

The following formulas defined in reference [1] are used:

\[R = \frac {T_{shellin} - T_{shellout}} {T_{tubeout} - T_{tubein}} P = \frac {T_{tubeout} - T_{tubein}} {T_{shellin} - T_{tubein}}\]

References

[1] R. A. Bowman, A. C. Mueller, and W. M. Nagle, “Mean Temperature Difference in Design”, Transactions of the ASME 62, 1940, pp:283-294. .

Examples

First import the module heatexchangers.

>>> from pychemengg.heattransfer import heatexchangers as hx 
>>> hx1 = hx.FCorrectionFactor()
>>> hx1.calc_R_P(T_shellin=300, T_shellout=200,
                             T_tubein=100, T_tubeout=200)
(1.0, 0.5)

oneshell2ntubepasses(T_tubein=None, T_tubeout=None, T_shellin=None, T_shellout=None)[source]¶

To find ‘F’ correction factor for LMTD. Use when shell passes = 1 and tube passes = 2, 4, 6, 8, etc

Parameters

T_tubeinint or float: Temperature of tube side (or cold) fluid at inlet.
T_tubeoutint or float: Temperature of tube side (or cold) fluid at outlet.
T_shellinint or float: Temperature of shell side (or hot) fluid at inlet.
T_shelloutint or float: Temperature of shell side (or hot) fluid at outlet.

Returns

Fint or float: ‘F’ correction factor for LMTD.

Raises

ValueError with message ‘math domain error’: If negative number is being passed to the ‘log’ function

Notes

Equation number (6) of reference [1] is used.

This is the same equation that is used to generate plots presented in most textbooks.

References

[1] R. A. Bowman, A. C. Mueller, and W. M. Nagle, “Mean Temperature Difference in Design”, Transactions of the ASME 62, 1940, pp:283-294. .

Examples

First import the module heatexchangers.

>>> from pychemengg.heattransfer import heatexchangers as hx 
>>> hx1 = hx.FCorrectionFactor()
>>> hx1.oneshell2ntubepasses(T_shellin=300, T_shellout=200,
                             T_tubein=100, T_tubeout=200)
0.8022781617244771

singlepass_crossflow_bothmixed(T_tubein=None, T_tubeout=None, T_shellin=None, T_shellout=None)[source]¶

To find ‘F’ correction factor for LMTD. Use for single pass cross flow with both fluids mixed.

Parameters

T_tubeinint or float: Temperature of tube side (or cold) fluid at inlet.
T_tubeoutint or float: Temperature of tube side (or cold) fluid at outlet.
T_shellinint or float: Temperature of shell side (or hot) fluid at inlet.
T_shelloutint or float: Temperature of shell side (or hot) fluid at outlet.

Returns

Fint or float: ‘F’ correction factor for LMTD.

Notes

Equation number (12) of reference [1] is used.

This is the same equation that is used to generate plots presented in most textbooks.

References

[1] R. A. Bowman, A. C. Mueller, and W. M. Nagle, “Mean Temperature Difference in Design”, Transactions of the ASME 62, 1940, pp:283-294. .

Examples

First import the module heatexchangers.

>>> from pychemengg.heattransfer import heatexchangers as hx 
>>> hx1 = hx.FCorrectionFactor()
>>> hx1.singlepass_crossflow_bothmixed(T_shellin=300, T_shellout=200,
                                         T_tubein=100, T_tubeout=200)
0.7959050946318332

singlepass_crossflow_bothunmixed(T_tubein=None, T_tubeout=None, T_shellin=None, T_shellout=None)[source]¶

To find ‘F’ correction factor for LMTD. Use for single pass cross flow with both fluids unmixed.

Parameters

T_tubeinint or float: Temperature of tube side (or cold) fluid at inlet.
T_tubeoutint or float: Temperature of tube side (or cold) fluid at outlet.
T_shellinint or float: Temperature of shell side (or hot) fluid at inlet.
T_shelloutint or float: Temperature of shell side (or hot) fluid at outlet.

Returns

Fint or float: ‘F’ correction factor for LMTD.

Notes

Equation number (10) of reference [1] is used.

This is the same equation that is used to generate plots presented in most textbooks.

References

[1] R. A. Bowman, A. C. Mueller, and W. M. Nagle, “Mean Temperature Difference in Design”, Transactions of the ASME 62, 1940, pp:283-294. .

Examples

First import the module heatexchangers.

>>> from pychemengg.heattransfer import heatexchangers as hx 
>>> hx1 = hx.FCorrectionFactor()
>>> hx1.singlepass_crossflow_bothunmixed(T_shellin=300, T_shellout=200,
                                         T_tubein=100, T_tubeout=200)
0.8945911509910063

singlepass_crossflow_oneunmixed(T_tubein=None, T_tubeout=None, T_shellin=None, T_shellout=None)[source]¶

To find ‘F’ correction factor for LMTD. Use for single pass cross flow with one fluid unmixed.

Parameters

T_tubeinint or float: Temperature of tube side (or cold) fluid at inlet.
T_tubeoutint or float: Temperature of tube side (or cold) fluid at outlet.
T_shellinint or float: Temperature of shell side (or hot) fluid at inlet.
T_shelloutint or float: Temperature of shell side (or hot) fluid at outlet.

Returns

Fint or float: ‘F’ correction factor for LMTD.

Notes

Equation number (11) of reference [1] is used.

This is the same equation that is used to generate plots presented in most textbooks.

References

[1] R. A. Bowman, A. C. Mueller, and W. M. Nagle, “Mean Temperature Difference in Design”, Transactions of the ASME 62, 1940, pp:283-294. .

Examples

First import the module heatexchangers.

>>> from pychemengg.heattransfer import heatexchangers as hx 
>>> hx1 = hx.FCorrectionFactor()
>>> hx1.singlepass_crossflow_oneunmixed(T_shellin=300, T_shellout=200,
                                         T_tubein=100, T_tubeout=200)
0.8464626304853572

twoshell4ntubepasses(T_tubein=None, T_tubeout=None, T_shellin=None, T_shellout=None)[source]¶

To find ‘F’ correction factor for LMTD. Use when shell passes = 2 and tube passes = 4, 8, 12, etc

Parameters

T_tubeinint or float: Temperature of tube side (or cold) fluid at inlet.
T_tubeoutint or float: Temperature of tube side (or cold) fluid at outlet.
T_shellinint or float: Temperature of shell side (or hot) fluid at inlet.
T_shelloutint or float: Temperature of shell side (or hot) fluid at outlet.

Returns

Fint or float: ‘F’ correction factor for LMTD.

Raises

ValueError with message ‘math domain error’: If negative number is being passed to the ‘log’ function

Notes

Equation number (8) of reference [1] is used.

This is the same equation used to generate plots presented in most textbooks.

References

[1] R. A. Bowman, A. C. Mueller, and W. M. Nagle, “Mean Temperature Difference in Design”, Transactions of the ASME 62, 1940, pp:283-294. .

Examples

First import the module heatexchangers.

>>> from pychemengg.heattransfer import heatexchangers as hx 
>>> hx1 = hx.FCorrectionFactor()
>>> hx1.twoshell4ntubepasses(T_shellin=300, T_shellout=200,
                             T_tubein=100, T_tubeout=200)
0.9568453972970873