A Coefficient to account for using average latent heat of vaporization A Pure water permeability constant, kg/m . s. atm 2
A B Heat transfer area of brine heater, m2 A j Heat transfer area of rejection section, m2
Am Total membrane area of membrane in RO process, m2
1
Am Total membrane area of stage 1 in RO process, m2
2
Am Total membrane area of stage 2 in RO process, m2 AR Heat transfer area of recovery section, m2 AT Total heat transfer area of MSF process, m2 B Salt permeability constant, m/s
Br- Bromine ions
Bref Reference blow down flow rate, m3/h BVPH Brine velocity in pre-heater, m/s
C 1 Electromechanical equipment cost, $ C 2 Civil work cost, $
C 3 Electro-chlorination cost, $ C 4 Brine disposal cost, $
C 5 Steam cost, $/y
C 6 Chemical treatment cost, $/y
C 7 Power cost, $/y
C 8 Spares cost, $/y
Nomenclature
C 9 Labour cost, $/y
Ca++ Calcium ions
CC eq Total equipment cost, $
CCERS Energy recovery system capital cost, $ CCHPP High pressure pump capital cost, $ CCprm Permeator capital cost, $
CCSWIP Seawater intake and pre-treatment capital cost, $ CCCW Civil work capital cost, $
Cche Chemicals, $/m prod 3
Cd Channel diameter, m
CDCC Direct capital investment, $/y CDCLIC Direct capital less intake cost, $/y
energy
C Energy (pumping), $/m prod 3
Ch Channel height, m
CH Hybrid cost, $/m3
CHD Concentration of total potable water product stream in hybrid process, ppm CHBD Concentration of total retentate product stream in hybrid process, ppm
CIC Annual plant intake-outfall cost, $ CICC Indirect capital investment, $/y CIref Reference intake outfall cost, $
Cl- Chloride ions
Nomenclature
CL Channel length, m
Clast Concentration of brine stream from last stage of heat rejection section, ppm.
Labour
C Labour cost, $/m prod 3
CMBD Concentration of reject stream leaving heat rejection section and entering ERS, ppm
CMF Feed (seawater) concentration, ppm
CMR Concentration of recycle stream (from splitter to heat recovery section), ppm CMSMF Concentration of feed stream to MSF-M process, ppm
COC Capital charge operational cost, $/y COch Chemical treatment cost, $/y COe Power/energy cost, $/y
COOMC Operating and maintenance cost, $/y COrp Permeator replacement cost, $/y
COs Spares cost, $/y
COMC Operating and maintenance cost, $/y
Cp Heat capacity, KJ/kg.K
Cpr Avg. Specific heat capacity, recovery section, KJ/kg.K Cpj Avg. Specific heat capacity, rejection section, KJ/kg.K
Recovery
C Capital recovery factor
spares
C Spares, $/m prod 3
CTAC Total annual cost, $/y
CW Channel width, m
Nomenclature
(CO3)-- Carbonates ions
RF
CRO Concentration of stream entering SWIP, ppm
1
CRF Concentration of stream entering stage 1 in RO process, ppm
2
CRF Concentration of stream entering stage 2 in RO process, ppm
RP
CRO Concentration of total potable water product stream in RO process, ppm
1
CRP Concentration of permeate stream from stage 1 in RO process, ppm
2
CRP Concentration of permeate stream from stage 2 in RO process, ppm
RR
CRO Concentration of retentate product stream in RO process, ppm
1
CRR Concentration of retentate stream from stage 1 in RO process, ppm
2
CRR Concentration of retentate stream from stage 2 in RO process, ppm
1
CRM Membrane wall concentration in stage 1 of RO process, ppm
2
CRM Membrane wall concentration in stage 2 of RO process, ppm D Diffusion coefficient of salt (NaCl) in seawater, m2/s
dp Specific surface diameter, m
effERS Efficiency of energy recovery system effHPP Efficiency of high pressure pump effSWIP Efficiency of intake pump
f C Load factor
Fref Reference feed flow rate, m3/h H3BO3-
Boric acid ions
i Number of ions for ionizable solutes ID Inside diameter of condenser tubes, m
S
JS Membrane salt flux in stage S (S=1,2) of RO process, kg.m2.h
W
JS Membrane water flux in stage S (S=1,2) of RO process, kg.m2.h
Nomenclature
k S Mass transfer coefficient in stage S, m/s
K+ Potassium ions
LT Tube length, m
M1-7 Mixer 1-7 respectively
Mg++ Magnesium ions
MS Molecular weight of solute
Na+ Sodium ions
Nj Nymber of rejection stages
NM1 Number of membranes in stage 1 of RO process NM2 Number of membranes in stage 2 of RO process NR Number of stages in heat recovery stages OD Outside diameter of condenser tubes, m PSWIP SWIP outlet pressure, bar
0
PF Pressure of stream entering HPP1 in RO process, bar
1
PF Pressure of stream entering stage 1 of RO process, bar
2
PF Pressure of stream entering stage 2 of RO process, bar
P
PH Pressure of total potable water product stream in hybrid MSF-RO process, bar
P
PRO Pressure of total potable water product stream in RO process, bar
1
PP Stage 1 permeate stream pressure in RO process, bar
2
PP Stage 2 permeate stream pressure in RO process, bar
R
PRO Pressure of total retentate stream in RO process, bar
R
PH Pressure of total retentate stream in hybrid MSF-RO process, bar
1
PR Stage 1 retentate stream pressure in RO process, bar
Nomenclature
2
PR Stage 2 retentate stream pressure in RO process, bar
3
PR Pressure of retentate stream entering ERS in RO/hybrid MSF-RO process, bar
P_ avg
PS Average pressure in the fiber bore in stage S, atm
R_ avg
PS Average pressure on the shell side of the fiber bundle in stage S, atm R Ideal gas constant, Nm/kg mole. K
ReS Reynolds number in stage S
RH Specific heat ratio (WMRCpR/WMFCpj ) Ri Inner radius of the fiber bundle, m Ro Outer radius of the fiber bundle, m
r1 Split ratio 1
r2 Split ratio 2
r3 Split ratio 3
ri Inner fiber radius, m
ro Outer fiber radius, m
sWCW Specific cooling water flow rate (ratio) ScS Schmidt number in stage S
ShS Sherwood number in stage S
T1 Temperature of reject coolant stream in MSF-BR process, °C
T2 Temperature of brine stream entering the brine heater in MSF process, oC T3 Top brine temperature, oC
T4 Temperature of brine stream leaving last stage in the heat recovery section of MSF-BR process, °C
T5 Temperature of brine stream leaving last stage in the heat rejection section of MSF-BR process, °C
T6 Temperature of recycle stream in MSF-BR process, °C
Nomenclature
TBD Temperature of reject stream in MSF-BR process, oC
TBHD Temperature of total retentate product stream in hybrid MSF-RO process,
oC
TD Temperature of distillate product stream in MSF process, oC
TDM Average temperature of distillate product stream in MSF process, oC THD Temperature of total potable water product stream in hybrid MSF-RO
process, oC
TS Steam temperature, oC
TSea Seawater temperature/ Feed temperature, oC
UB Overall heat transfer coefficient in brine heater, kW/m2.K Uj Overall heat transfer coefficient in rejection section, kW/m2.K UR Overall heat transfer coefficient in recovery section, kW/m2.K UBcal Calculated overall heat transfer coefficient in brine heater, kW/m2.K Ujcal Calculated overall heat transfer coefficient in rejection section, kW/m2.K
S
US Superficial velocity in stage S, m/s
si
US Superficial velocity at the inner radius of the fiber bundle in stage S, m/s
so
US Superficial velocity at the outer radius of the fiber bundle in stage S, m/s URcal Calculated overall heat transfer coefficient in recovery section, kW/m2.K V B Brine velocity in brine heater, m/s
Vj Brine velocity in rejection section, m/s V R Brine velocity in recovery section, m/s
W
VS Permeation velocity in stage S, m/h WFC Flow rate through the condensers, MGD
Nomenclature
WFC1 Flow rate through the condensers for K+1 stage, MGD
WHD Total potable water product stream flow rate in hybrid MSF-RO process, m3/h
WHBD Total retentate brine product stream flow rate in hybrid MSF-RO process, m3/h
Wlast Flow rate of flashing brine stream leaving the last stage of heat rejection section in MSF-M and MSF process, m /h3
WM Flow rate of makeup stream in MSF process, m /h3 WMBD Flow rate of rejected stream in MSF process, m /h3 WMCW Flow rate of reject coolant stream in MSF process, m /h3
WMD Flow rate of total potable water product stream in MSF process, m /h3 WMF Feed flow rate in MSF process, m /h3
WMSC Feed flow rate of seawater (before mixing) of MSF-M, m3/h WMSMF Feed flow rate of MSF-M, m3/h
WL Stage length, m
WMR Flow rate of recycle stream in MSF-M and MSF-BR process, m /h3
WMRWBD Flow rate of brine stream leaving mixer M1 and entering splitter S2 in MSF- BR process, m3/h
WS Flow rate of steam fed to brine heater, m /h3
WW Stage Width, m
RF
WRO Flow rate of stream entering SWIP, m /h3
1
WRF Feed flow rate to stage 1 of RO process, m /h3
2
WRF Feed flow rate to stage 2 of RO process, m /h3
RP
WRO Flow rate of total permeate product flow rate in RO process, m /h3
1
WRP Flow rate of permeate stream from stage 1 of RO process, m /h3
2
WRP Flow rate of permeate stream from stage 2 of RO process, m /h3
Nomenclature
RR
WRO Flow rate of total retentate product flow rate in RO process, m /h3
1
WRR Flow rate of retentate stream from stage 1 in RO process, m /h3
2
WRR Flow rate of retentate stream from stage 2 in RO process, m /h3
1
WRS Flow rate of stream leaving splitter 1 and entering stage 1 in RO process, m /h3
2
WRS Flow rate of stream leaving splitter 2 and entering mixer 2 in RO process, m /h3
1
WR Flow rate of stream leaving splitter 1 and entering mixer 3 of RO process, m /h3
WY Yearly capacity, m3/y