Convection to jacketed vessels (ht.conv_jacket)¶
- ht.conv_jacket.Lehrer(m, Dtank, Djacket, H, Dinlet, rho, Cp, k, mu, muw=None, isobaric_expansion=None, dT=None, inlettype='tangential', inletlocation='auto')[source]¶
Calculates average heat transfer coefficient for a jacket around a vessel according to [1] as described in [2].
For Radial inlets:
For Tangential inlets:
- Parameters
- m
float
Mass flow rate of fluid, [kg/s]
- Dtank
float
Outer diameter of tank or vessel surrounded by jacket, [m]
- Djacket
float
Inner diameter of jacket surrounding a vessel or tank, [m]
- H
float
Height of the vessel or tank, [m]
- Dinlet
float
Inner diameter of inlet into the jacket, [m]
- rho
float
Density of the fluid at Tm [kg/m^3]
- Cp
float
Heat capacity of fluid at Tm [J/kg/K]
- k
float
Thermal conductivity of fluid at Tm [W/m/K]
- mu
float
Viscosity of fluid at Tm [Pa*s]
- muw
float
,optional
Viscosity of fluid at Tw [Pa*s]
- isobaric_expansion
float
,optional
Constant pressure expansivity of a fluid, [m^3/mol/K]
- dT
float
,optional
Temperature difference of fluid in jacket, [K]
- inlettype
str
,optional
Either ‘tangential’ or ‘radial’
- inletlocation
str
,optional
Either ‘top’ or ‘bottom’ or ‘auto’
- m
- Returns
- h
float
Average heat transfer coefficient inside the jacket [W/m^2/K]
- h
Notes
If the fluid is heated and enters from the bottom, natural convection assists the heat transfer and the Grashof term is added; if it were to enter from the top, it would be subtracted. The situation is reversed if entry is from the top.
References
- 1
Lehrer, Isaac H. “Jacket-Side Nusselt Number.” Industrial & Engineering Chemistry Process Design and Development 9, no. 4 (October 1, 1970): 553-58. doi:10.1021/i260036a010.
- 2(1,2,3)
Gesellschaft, V. D. I., ed. VDI Heat Atlas. 2nd edition. Berlin; New York:: Springer, 2010.
Examples
Example as in [2], matches completely.
>>> Lehrer(m=2.5, Dtank=0.6, Djacket=0.65, H=0.6, Dinlet=0.025, dT=20., ... rho=995.7, Cp=4178.1, k=0.615, mu=798E-6, muw=355E-6) 2922.128124761829
Examples similar to in [2] but covering the other case:
>>> Lehrer(m=2.5, Dtank=0.6, Djacket=0.65, H=0.6, Dinlet=0.025, dT=20., ... rho=995.7, Cp=4178.1, k=0.615, mu=798E-6, muw=355E-6, ... inlettype='radial', isobaric_expansion=0.000303) 3269.4389632666557
- ht.conv_jacket.Stein_Schmidt(m, Dtank, Djacket, H, Dinlet, rho, Cp, k, mu, muw=None, rhow=None, inlettype='tangential', inletlocation='auto', roughness=0.0)[source]¶
Calculates average heat transfer coefficient for a jacket around a vessel according to [1] as described in [2].
For Radial inlets:
For Tangential inlets:
- Parameters
- m
float
Mass flow rate of fluid, [kg/m^3]
- Dtank
float
Outer diameter of tank or vessel surrounded by jacket, [m]
- Djacket
float
Inner diameter of jacket surrounding a vessel or tank, [m]
- H
float
Height of the vessel or tank, [m]
- Dinlet
float
Inner diameter of inlet into the jacket, [m]
- rho
float
Density of the fluid at Tm [kg/m^3]
- Cp
float
Heat capacity of fluid at Tm [J/kg/K]
- k
float
Thermal conductivity of fluid at Tm [W/m/K]
- mu
float
Viscosity of fluid at Tm [Pa*s]
- muw
float
,optional
Viscosity of fluid at Tw [Pa*s]
- rhow
float
,optional
Density of the fluid at Tw [kg/m^3]
- inlettype
str
,optional
Either ‘tangential’ or ‘radial’
- inletlocation
str
,optional
Either ‘top’ or ‘bottom’ or ‘auto’
- roughness
float
,optional
Roughness of the tank walls [m]
- m
- Returns
- h
float
Average transfer coefficient inside the jacket [W/m^2/K]
- h
Notes
[1] is in German and has not been reviewed. Multiple other formulations are considered in [1].
If the fluid is heated and enters from the bottom, natural convection assists the heat transfer and the Grashof term is added; if it were to enter from the top, it would be subtracted. The situation is reversed if entry is from the top.
References
- 1(1,2,3)
Stein, Prof Dr-Ing Werner Alexander, and Dipl-Ing (FH) Wolfgang Schmidt. “Wärmeübergang auf der Wärmeträgerseite eines Rührbehälters mit einem einfachen Mantel.” Forschung im Ingenieurwesen 59, no. 5 (May 1993): 73-90. doi:10.1007/BF02561203.
- 2(1,2)
Gesellschaft, V. D. I., ed. VDI Heat Atlas. 2nd edition. Berlin; New York:: Springer, 2010.
Examples
Example as in [2], matches in all but friction factor:
>>> Stein_Schmidt(m=2.5, Dtank=0.6, Djacket=0.65, H=0.6, Dinlet=0.025, ... rho=995.7, Cp=4178.1, k=0.615, mu=798E-6, muw=355E-6, rhow=971.8) 5695.2041698088615