Page 342 - Mechanical Engineers' Handbook (Volume 4)

Nomenclature 331

8
Gravitational constant 4.17 10 lb f ft/lb hr 2 1.0
g c
2
2
Heat transfer coeff., hot fluid Btu/hr ft F W/m K
h hot
2
2
Heat transfer coeff., cold fluid Btu/hr ft F W/m K
h cold
2
2
Heat transfer coeff., boiling Btu/hr ft F W/m K
h b
2
Heat transfer coeff., condensing Btu/hr ft F W/m K
2
h c
2
2
Heat transfer coeff., conv. boiling Btu/hr ft F W/m K
h cb
2
Heat transfer coeff., cond. film Btu/hr ft F W/m K
2
h cƒ
Heat transfer coeff., inside Btu/hr ft F W/m K
2
2
h i
2
Heat transfer coeff., liq. film Btu/hr ft F W/m K
2
h l
Heat transfer coeff., Nusselt Btu/hr ft F W/m K
2
2
h N
2
Heat transfer coeff., nucleate boiling Btu/hr ft F W/m K
2
h nb
2
2
Heat transfer coeff., outside Btu/hr ft F W/m K
h o
2
2
Heat transfer coeff., sens. vapor Btu/hr ft F W/m K
h sv
2
2
Heat transfer coeff., vapor phase Btu/hr ft F W/m K
h v
Wallis dimensionless gas velocity — —
J g
Thermal conductivity, fluid Btu/hr ft F W/m K
k ƒ
Thermal conductivity, liquid Btu/hr ft F W/m K
k l
Thermal conductivity, wall Btu/hr ft F W/m K
k w
L Tube length ft m
Baffle spacing ft m
L bc
Maximum unsupported length in. use U.S. only
L su
MTD Mean temperature difference F K
NP Number of tube passes — —
NT Number of tubes — —
NTU Number of transfer units — —
P Pressure psia use U.S. only
Critical pressure psia use U.S. only
P c
Fan power use S.I. only W
P ƒ
Pr Prandtl number — —
Tube pitch ft m
P t
Maximum allowable heat flux Btu/hr ft 2 use U.S. only
q max
q Heat flux Btu/hr ft 2 use U.S. only
Q Heat duty Btu/hr W
Sensible vapor heat flux Btu/hr ft 2 W/m 2
q sv
Total heat flux Btu/hr ft 2 W/m 2
q t
Re Reynolds number — —
Reynolds number, condensate — —
Re c
2
Fouling resistance, inside Fft hr/Btu K m /W
2
R ƒ i
2
Fouling resistance, outside Fft hr/Btu K m /W
2
R ƒ o
2
2
Heat transfer resistance, inside Fft hr/Btu K m /W
R h i
2
2
Heat transfer resistance, outside Fft hr/Btu K m /W
R h o
2
2
Heat transfer resistance, wall Fft hr/Btu K m /W
R w
Crossflow area, shellside ft 2 m 2
S s
Crossflow area, tubeside ft 2 m 2
S t
Temperature, cold fluid inlet F C
t 1
Temperature, hot fluid inlet F C
T 1
Temperature, cold fluid outlet F C
t 2
Temperature, hot fluid outlet F C
T 2
Hot inlet—cold outlet temperature F C
T A
Hot outlet—cold inlet temperature F C
T B
Temperature, hot fluid F C
T hot
Temperature, cold fluid F C
T cold
Saturation temperature F C
T s
Wall temperature F C
T w
Wall temperature, hot fluid side F C
T w, hot