Page 7 - Design and Operation of Heat Exchangers and their Networks

Nomenclature

a absorptivity;
wave amplitude (m)
2
A heat transfer area (m )
2
A c free-flow area (m );
2
cross-sectional area (m )
2
A sb shell-to-baffle leakage area (m )
2
A sc shell-side crossflow area (m )
2
A bp shell-to-tube-bundle bypass area (m )
2
A bt baffle-hole-to-tube leakage area (m )
b plate spacing (m)
b t thickness of flat tube (m)
B ratio of thermal capacity of fluid to that of solid material, B¼C/C w
width of plate (m)
B p
c control vector
c splitting factor;
3
concentration (mol/m );
specific thermal capacity (J/kgK)
specific isobaric thermal capacity (J/kgK)
c p
C thermal capacity, C¼Mc p (J/K)
_ C thermal capacity rate, _ C ¼ _mc p (W/K)
annuity factor for capital appreciation
C a
0 annuity factor for fixed annual repayment of loan
C a
2
annual cost per unit area ($/m yr)
C A
2
cost per unit area ($/m )
C A,tot
C E annual investment cost ($/yr)
C el price of electrical energy ($/MWh)
CN criterion number of a spiral heat exchanger
Co convection number
C RF area reserve factor
C U annual utility cost ($/yr)
d design vector
d b baffle diameter (m)
d bt baffle-hole diameter (m)
d ctl tube-bundle outer tube center diameter (m)
d h hydraulic diameter (m)
d h,s shell-side hydraulic diameter (m)
tube outside diameter (m)
d o
tube-bundle outer tube limit diameter (m)
d otl
shell inside diameter (m)
d s
D axial dispersion coefficient (W/mK);
flexibility index
Dn Dean number, Dn¼Re(r/r c ) 1/2
xi