Coker A.K. Fortran Programs for Chemical Process Design, Analysis, and Simulation
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RETURN
END
THIS PROGRAM CALCULATES THE LOG MEAN TEMPERATURE DIFFERENCE,
LMTD (oF)
SUBROUTINE LOGMTD (THI, TH2, TCI, TC2, LMTD)
REAL LMTD
DELTI = THI - TC2
DELT2 = TH2 - TCI
LMTD = ABS((DELTI - DELT2)/ALOG (DELTI/DELT2))
RETURN
END
THIS SUBPROGRAM EVALUATES THE HEAT TRANSFER FILM COEFFICIENT
IN THE VAPOR STATE OF A DOUBLE PIPE HEAT EXCHANGER.
******************************************************************
FUNCTION HTFCV (CPI, GI, DEQI)
HTFCV = (0.OI44*CPI*(GI**O.8))/(DEQI**0.2)
RETURN
END
THIS SUBPROGRAM EVALUATES THE HEAT TRANSFER FILM COEFFICIENT
IN THE LIQUID STATE OF A DOUBLE PIPE HEAT EXCHANGER.
FUNCTION HTFCL (RE1, PRI, KI, DI)
REAL K1
HTFCL = O.023*(REI**O.8)*(PRI**0.333)*(KI/DI)*I.O
RETURN
END
THIS SUBPROGRAM EVALUATES THE HEAT TRANSFER FILM COEFFICIENT
FOR REYNOLDS NUMBER LESS THAN 2100.0 OF A DOUBLE PIPE
HEAT EXCHANGER
FUNCTION HTFCJ (RE, PR, KI, DI, TLI)
REAL K1
HTFCJ = 1.86*(RE**0.333)*(PR**0.333)*(KI/DI)*(DI/TLI)**0.333
RETURN
END
707
CALCULATE THE FRICTION FACTOR IN THE SHELL SIDE OF THE DOUBLE
PIPE HEAT EXCHANGER (Dennis Wright: Basic Programs for chemical
engineers, Van Nostrand Reinhold company, NY 1986)
SUBROUTINE FFACTOR (RE, FACTOR)
IF (RE .GT. 2100) THEN
FACTOR = 0.00033/(RE**0.25)
ELSEIF (RE .LT. 2100) THEN
FACTOR = 16.0/RE
ENDIF
RETURN
END
THIS PROGRAM CALCULATES THE PRESSURE DROP FOR THE SHELL SIDE OF
A DOUBLE PIPE HEAT EXCHANGER
SUBROUTINE PDROP (FRICT, TLEN, NP, G, DEN, EQDIA, DROP)
DROP =
(4*FRICT*TLEN*NP*(G/3600.O)**2)/(64.4*DEN*EQDIA)
RETURN
END
THIS PROGRAM PRINTS THE RESULTS OF THE DOUBLE PIPE HEAT EXCHANGERS
SUBROUTINE RESULTS
CHARACTER*30 FLUIDT, FLUIDS, FLUIDF, TUBE, FTTUBE, FTSHELL
REAL IDTF, IDSF, IDFF, ODTF, ODSF, ODFF
REAL IDT, ODT, KT
REAL IDS, ODS, KS, KST
REAL IDF, ODF, KF, KFT
REAL LMTD
COMMON TUBE
COMMON/DATA/FTTUBE, FTSHELL, TDEN, SDEN
COMMON/DATAI/FLUIDT,IDT,ODT,WT,CPT,VIST,KT,TTI,TT2,FOLT,TL,NTP
COMMON/DATA2/FLUIDS,IDS,ODS,WS,CPS,VISS,KS,TSI,TS2,FOLS,KST,NSP
COMMON/DATA3/FLUIDF,IDF,ODF,WF,CPF,VISF,KF,TFI,TF2,FOLF,
* FHT,FTHICK,NF,KFT,NFP
COMMON/DATA4/PI
COMMON/DATA5/IDTF,IDSF,IDFF,ODTF,ODSF,ODFF
COMMON/RESI/VELT,RET,PRT,FRICTT,DROPT,HTFT,HIFTU
COMMON/RES2/VELS,RES,PRS,FRICTS,DROPS,HTFS,HIFS
COMMON/RES3/VELF,REF,PRF,FRICTF,DROPF,HTFF,HIFF,X,FE,ESEF,HIFD,
*UO
COMMON/RES4/LMTD,AREA,Q
WRITE (i, 120)
708
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
FORMAT (/,18X,'DOUBLE PIPE HEAT EXCHANGER RATING',/,18X,
*
'USING BARE-TUBES/LONGITUDINAL FINNED TUBES'/,18X,
* 'FORCED CONVECTION WITH NO CHANGE OF PHASE')
WRITE (I, 130)
FORMAT (IH ,78(IH*))
WRITE
( 1
FORMAT (
,
14o)
45X, 'TUBE SIDE', 10X, 'SHELL SIDE' )
WRITE (i, 150)
FORMAT ( 78 ( IH- ) )
WRITE (i, 160) FTTUBE, FTSHELL
FORMAT (2X,'FLUID NAME:', T50, AI5, T65, AI5)
IF (TUBE .EQ. 'FINS' .OR. TUBE .EQ. 'fins') THEN
WRITE (I, 170) FLUIDT, FLUIDF
FORMAT (2X,'TYPE OF PHASE FLOW:', T50, AI5, T65, AI5)
WRITE (i, 180) WT, WF
FORMAT (2X,'FLUID FLOW RATE, ib/hr.:', T45, FI0.0, T60, FI0.0)
WRITE (i, 190) CPT, CPF
FORMAT (2X,'SPECIFIC HEAT CAPACITY, Btu/Ib.oF:'
T60, F8.3)
, T45, F8.3,
WRITE (i, 200) TDEN, SDEN
FORMAT (2X,'FLUID DENSITY, ib/ft^3.: ' , T45, F8.3, T60, F8.3)
WRITE (I, 210) VIST, VISF
FORMAT (2X,'FLUID VISCOSITY, cP:', T45, F8.3, T60, F8.3)
WRITE (i, 220) KT, KF
FORMAT (2X,'FLUID THERMAL COND., Btu/Ib.oF:'
T60, F8.3)
, T45, F8.3,
WRITE (I, 230) TTI, TFI
FORMAT (2X,'FLUID INLET TEMPERATURE, oF:', T45, F8.3,
T60, F8.3)
WRITE (i, 240) TT2, TF2
FORMAT (2X,'FLUID OUTLET TEMPERATURE, oF:', T45, F8.3,
T60, F8.3)
WRITE (i, 250) IDT, IDF
FORMAT (2X,'INSIDE DIAMETER, inch:', T45, F8.3, T60, F8.3)
WRITE (i, 260) ODT, ODF
FORMAT (2X,'OUTSIDE DIAMETER, inch:', T45, F8.3, T60, F8.3)
WRITE (i, 270) FOLT, FOLF
FORMAT (2X,'FOULING FACTOR:', T45, F8.3, T60, F8.3)
WRITE (i, 280) TL, NTP
FORMAT (2X,'TUBE LENGTH, ft.:', T45, F8.3,/,
2X,'NUMBER OF TUBE PASSES:', T45, I2)
709
WRITE (i, 290) NF, FHT, FTHICK
290 FORMAT (2X, 'NUMBER OF FINS:', T45, I2,/,
* 2X,'FIN HEIGHT, inch:', T45, F8.3,/,
* 2X,'FIN THICKNESS, inch:', T45, F8.3)
WRITE (I, 300) KFT
300 FORMAT (2X,'THERMAL COND. TUBE MATERIAL, Btu/hr.ft.oF:',
* T45,F8.3)
WRITE (i, 310) VELT, VELF
310 FORMAT (2X,'FLUID VELOCITY, ft/sec.:', T45, F8.3, T60, F8.3)
WRITE (i, 320) RET, REF
320 FORMAT (2X,'REYNOLDS NUMBER:' , T45, F9.0, T60, F9.0)
WRITE (i, 330) PRT, PRF
330 FORMAT (2X,'PRANDTL NUMBER:', T45, F8.4, T60, F8.3)
WRITE (i, 340) FRICTT, FRICTF
340 FORMAT (2X,'FRICTION FACTOR (ft^2/in^2): ' , T45, F8.6, T60, F8.6)
WRITE (i, 350) DROPT, DROPF
350 FORMAT (2X,'PRESSURE DROP, psi.:', T45, F8.4, T60, F8.4)
WRITE (i, 360) X, FE, ESEF
360 FORMAT (2X,'FIN MODULUS:', T45, F8.3,/,
* 2X,'FIN EFFICIENCY, %:', T45, F8.3,/,
* 2X,'EFFECTIVE SURFACE EFFICIENCY, %:', T45, F8.3)
WRITE (i, 370) LMTD
370 FORMAT (2X,'LOG MEAN TEMP. DIFF., oF:', T45, F8.2)
WRITE (i, 380) HIFTU, HIFF
380 FORMAT (2X,'HEAT TRANSFER FILM COEFF. CORRECTED',/,2X,
* 'FOR FOULING:, Btu/hr.ft^2.oF: ' , T45, F9.2, T60, F9.2)
WRITE (i, 390) UO
390 FORMAT (2X,'OVERALL HEAT TRANSFER COEFF., Btu/hr.ft^2.oF: ' ,
* T45, F9.2)
WRITE (I, 400) Q, AREA
400 FORMAT (2X,'HEAT LOAD ON UNIT, Btu/hr.:', T45, FI2.1,/,
* 2X,'HEAT TRANSFER SURFACE ft^2.: ' , T45, F8.3)
ELSEIF (TUBE .EQ. 'BARE-TUBE' .OR. TUBE .EQ. 'bare-tube') THEN
WRITE (i, 410) FLUIDT, FLUIDS
410 FORMAT (2X,'TYPE OF PHASE FLOW:', T45, AI5, T60, AI5)
WRITE (i, 420) WT, WS
420 FORMAT (2X,'FLUID FLOWRATE:, ib/hr.:', T45, FI0.0, T60, FI0.0)
WRITE (i, 430) CPT, CPS
430 FORMAT (2X,'SPECIFIC HEAT CAPACITY, Btu/ib.oF:', T45, FS.3,T60,
* F8.3)
WRITE (i, 440) TDEN, SDEN
440 FORMAT (2X,'FLUID DENSITY, ib/ft^3: ' , T45, F8.3, T60, F8.3)
WRITE (i, 450) VIST, VISS
710
450 FORMAT (2X,'FLUID VISCOSITY, cP:', T45, F8.3, T60, F8.3)
WRITE (i, 460) KT, KS
460 FORMAT (2X,'FLUID THERMAL COND., Btu/Ib.oF:', T45, F8.3,
* T60, F8.3)
WRITE (i, 470) TTI, TSl
470 FORMAT (2X,'FLUID INLET TEMPERATURE, OF:',T45, F8.3, T60, F8.3)
WRITE (i, 480) TT2, TS2
480 FORMAT (2X,'FLUID OUTLET TEMPERATURE, oF:',T40, F8.3,T60,F8.3)
WRITE (i, 490) IDT, IDS
490 FORMAT (2X,'INSIDE DIAMETER, inch:',T45, F8.3, T60, F8.3)
WRITE (i, 500) ODT, ODS
500 FORMAT (2X,'OUTSIDE DIAMETER, inch:', T45, F8.3, T60, F8.3)
WRITE (I, 510) FOLT, FOLS
510 FORMAT (2X,'FOULING FACTOR:', T45, F8.3, T60, F8.3)
WRITE (i, 520) EFT
520 FORMAT (2X,'THERMAL COND. TUBE MATERIAL, Btu/hr.ft.oF:',
* T45, F8.3)
WRITE (i, 530) VELT, VELS
530 FORMAT (2X,'FLUID VELOCITY, ft/sec.:', T45, F8.3, T60, F8.3)
WRITE (i, 540) RET, RES
540 FORMAT (2X,'REYNOLDS NUMBER:', T45, F9.0, T60, F9.0)
WRITE (i, 550) PRT, PRS
550 FORMAT (2X,'PRANDTL NUMBER:', T45, F8.3, T60, F8.3)
WRITE (i, 560) FRICTT, FRICTS
560 FORMAT (2X,' FRICTION FACTOR (ft~2/in^2): ' , T45, F8.5,T60,F8.5)
WRITE (i, 570) DROPT, DROPS
570 FORMAT (2X,'PRESSURE DROP, psi:', T45, F8.4, T60, F8.4)
WRITE (i, 580) LMTD
580 FORMAT (2X,'LOG MEAN TEMP. DIFF., oF:', T45, F8.2)
WRITE (i, 590) HIFTU, HIFS
590 FORMAT (2X,'HEAT TRANSFER FILM COEFF. CORRECTED',/,2X,
* 'FOR FOULING:, Btu/hr.ft^2.oF: ' , T45, F9.2, T60, F9.2)
WRITE (i, 600) UO
600 FORMAT (2X,'OVERALL HEAT TRANSFER FILM COEFF., Btu/hr.ft^2.oF: ' ,
* T45, F9.2)
WRITE (i, 610) Q, AREA
610 FORMAT (2X,'HEAT LOAD ON UNIT , Btu/hr.:', T45, FI2.1,/,
* 2X,'HEAT TRANSFER SURFACE, ft^2.: ' , T45, F8.3)
ENDIF
WRITE (i, 620)
620 FORMAT (IH ,78(IH-))
C FORM FEED THE PRINTING PAPER TO TOP OF THE NEXT PAGE.
WRITE (i, *) CHAR(12)
RETURN
END
711
PROGRAM PROG84
THE SIZING OF AIR-COOLED HEAT EXCHANGERS.
THE PROGRAM PERFORMS PRELIMINARY AIR-COOLER DESIGN CALCULATIONS
WITH A RANGE OF INPUT DATA.
THE PROGRAM CALCULATES:
i.
2.
3.
4.
5.
6.
7.
8.
9.
i0.
THE NUMBER OF TUBE ROWS (TUBE BUNDLE DEPTH).
OUTLET AIR TEMPERATURE.
LOG MEAN TEMPERATURE DIFFERENCE.
TOTAL BARE-TUBE SURFACE AREA (BASED ON 1 inch OD TUBING
ON 2 3/8 inch TRIANGULAR SPACING.).
COOLER FACE AREA (plan area).
AIR VELOCITY ACROSS TUBES.
TOTAL AIR FLOW.
FAN HORSEPOWER (bhp = brake horsepower).
TOTAL BUNDLE WEIGHT.
TUBE BUNDLE WIDTH FOR A GIVEN TUBE LENGTH.
THIS PROGRAM IS BASED ON CORRELATIONS PRESENTED IN ARTICLES BY
E.C. Smith AND R. Brown. THE CORRELATIONS PRESENTED BY GRAPHS
AND TABLES IN THE ORIGINAL ARTICLES AND FITTED TO A SERIES OF
EQUATION BY W.W. Blackwell ARE USED IN THIS PROGRAM.
* TPO =
* LMTD =
* Q =
* TAO =
* F =
* BHP =
* WT =
* W =
R = NUMBER OF TUBE ROWS.
TPI = INLET PROCESS FLUID TEMPERATURE, oF.
TAI = INLET AIR TEMPERATURE, oF.
BTSA = BARE-TUBE SURFACE AREA BASED ON TUBE OD, ft^2.
FA = FACE AREA OF BUNDLE, ft^2.
FV = FACE VELOCITY OF AIR,ft^2.
TAOI = ESTIMATED AIR OUTLET TEMPERATURE, oF.
U = OVERALL HEAT-TRANSFER COEFFICIENT
(BASED ON BARE-TUBE OD) Btu/hr.ft^2oF.
OUTLET PROCESS FLUID TEMPERATURE, oF.
EFFECTIVE LOG MEAN TEMPERATURE DIFFERENCE, oF.
HEAT LOAD, Btu/hr.
CALCULATED OUTLET AIR TEMPERATURE, oF.
AIR FLOW OVER TUBES, std ft^3/min.
FAN HORSEPOWER, brake horsepower.
AIR-COOLER WEIGHT, lb.
TUBE BUNDLE, WIDTH, ft.
TL = TUBE LENGTH, ft.
CI,C2,C3,C4,C5,C6,C7,C8,C9,CI0 = CONSTANTS
REAL LMTD
OPEN (UNIT=3, FILE='DATA84.DAT', STATUS='OLD', ERR=I8)
OPEN (UNIT =i, FILE='PRN')
CONSTANTS USED IN THE PROGRAM
Cl = 3.1679
C2 = 3.7948
712
18
i00
19
ii0
C3 = 1.2557
C4 = 1.0031
C5 = 720.8542
C6 = 0.9530
C7 = 7.4212
C8 = 12.5342
C9 = 36.4
CI0 = 9.35
READ THE INLET PROCESS FLUID TEMPERATURE, oF: TPI
READ THE OUTLET PROCESS FLUID TEMPERATURE, oF: TPO
READ THE INLET AIR TEMPERATURE, oF: TAI
READ THE OVERALL HEAT-TRANSFER COEFFICIENT, Btu/hr.ft^2.oF: U
READ THE HEAT LOAD, Btu/hr.: Q
READ THE TUBE LENGTH, ft.: TL
READ (3, *
READ (3, *
GO TO 20
, ERR=I9) TPI, TPO, TAI
, ERR=I9) U, Q, TL
WRITE (*, i00)
FORMAT (6X, 'DATA FILE DOES NOT EXIST')
GO TO 999
WRITE (*, ii0)
FORMAT (6X, 'ERROR MESSAGE IN THE DATA VALUE')
GO TO 999
20
120
130
140
WRITE (I, 120)
FORMAT (///,20X,'AN AIR-COOLED HEAT EXCHANGER DESIGN',/,78(IH*))
WRITE (i, 130) TPI, TPO, TAI
FORMAT (6X,'INLET PROCESS FLUID TEMPERATURE, oF:',T60, F8.1,
/,6X,'OUTLET PROCESS FLUID TEMPERATURE, oF:',T60,F8.1,
/,6X,'INLET AIR TEMPERATURE, oF:',T60,F8.1)
WRITE (i, 140) U, Q, TL
FORMAT (6X,'OVERALL HEAT-TRANSFER COEFFICEINT, Btu/hr.ft^2.oF: '
T60, F8.1,/,6X,'HEAT LOAD, Btu/hr.:',T60, FI2.0,/,6X,
'TUBE LENGTH, ft.:', T60, F8.1)
CALCULATE THE NUMBER OF TUBE ROWS
R = C1 + C2*(ALOG((TPI-TAI)/U))
CALCULATE THE RATIO OF BARE-TUBE SURFACE AREA BASED ON THE
TUBE OD TO THE FACE AREA OF BUNDLE , RATIOI=BTSA/FA
RATIO1 = C3"(R**C4)
CALCULATE THE FACE VELOCITY OF AIR, ft/min.
FV = C5"(C6,*R)
713
150
160
C
25
170
180
190
w
WRITE (i, 150) R, RATIO1, FV
FORMAT (6X,'NUMBER OF TUBE ROWS:',T60,F6.1,/,6X,
'RATIO OF BARE-TUBE SURFACE TO FACE AREA OF BUNDLE:', T60, F6.1,
/, 6X, 'FACE VELOCITY OF AIR, ft./min.:', T60, F8.3)
CALCULATE THE ESTIMATED AIR OUTLET TEMPERATURE, oF: TAOI
TAOI = (0.005*U*((TPO+TPI)/2.0-TAI)) + TAI
WRITE (I, 160) TAOI
FORMAT (6X, 'ESTIMATED AIR OUTLET TEMPERATURE, oF:',T60, F8.3)
CALCULATE THE LOG MEAN TEMPERATURE DIFFERENCE, oF: LMTD.
VALI = (TPO-TAI)-(TPI-TAOI)
VAn2 = ALOG((TPO-TAI)/(TPI-TAOI))
LMTD = VALI/VAL2
CALCULATE BARE-TUBE SURFACE AREA BASED ON TUBE, OD: ft^2: BTSA
BTSA = Q/(U*LMTD)
CALCULATE THE FACE AREA OF BUNDLE, ft^2: FA
FA = BTSA/RATIOI
WRITE (i, 170) LMTD, BTSA, FA
FORMAT (6X,'EFFECTIVE LOG MEAN TEMPERATURE DIFFERENCE, oF:',T60,
F8.3, /, 6X,'BARE-TUBE SURFACE AREA BASED ON TUBE OD, ft^2: ' ,
T60, F8.1, /, 6X,'FACE AREA OF BUNDLE, ft^2:',T60,F8.1)
CALCULATED OUTLET AIR TEMPERATURE, oF: TAO
TAO = (Q/(FA*FV*I.08)) + TAI
WRITE (i, 180) TAO
FORMAT (6X,'CALCULATED OUTLET AIR TEMPERATURE, oF:', T60, F8.3)
A
NECESSARY CONDITION FOR SIZING AN AIR-COOLED EXCHANGER.
CHECK WHETHER THE DIFFERENCE BETWEEN THE CALCULATED AIR OUTLET
TEMPERATURE AND THE ESTIMATED AIR OUTLET TEMPERATURE IS GREATER
THAN/OR EQUAL TO 0.5 (i.e. (TAO-TAOI) .GE. 0.5))
IF THE DIFFERENCE IS GREATER THAN OR EQUAL TO 0.5, THEN SET THE
ESTIMATED AIR OUTLET TEMPERATURE EQUAL TO THE CALCULATED AIR
OUTLET TEMPERATURE AND REPEAT THE CALCULATION FROM THE LOG MEAN
TEMPERATURE DIFFERENCE.
IF ((TAO-TAOI) .GE. 0.5) THEN
WRITE (i, 190)
FORMAT (6X,'THE DIFFERENCE BETWEEN THE CALCULATED AIR', /, 6X,
'OUTLET TEMPERATURE AND THE ESTIMATED AIR OUTLET', /, 6X,
'TEMPERATURE IS GREATER THAN 0.5',T60,'TAO-TAOI >0.5')
TAOI = TAO
GO TO 25
ELSE
ENDIF
714
200
C
210
220
230
C
999
WRITE (i, 200) BTSA,FA
FORMAT (6X,'CALCULATED BARE-TUBE SURFACE AREA', /, 6X,
'BASED ON TUBE OUTSIDE DIAMETER, ft^2: ' , T60, F8.1,
/,6X,'FACE AREA OF BUNDLE, ft^2: ' , T60, F8.1)
CALCULATE AIR FLOW OVER TUBES, std ft^3/min.: F
F = FA*FV
CALCULATE FAN HORSEPOWER: BHP
BHP = BTSA/(C7+(C8*R))
CALCULATE AIR-COOLER WEIGHT, ib: WT.
WT = FA*(C9+(CI0*R))
CALCULATE TUBE BUNDLE WIDTH, ft: W
W = FA/TL
WRITE (i, 210) F, BHP
FORMAT (6X,'AIR FLOW OVER TUBES, std.ft^3/min.: ' , T60, F9.0,
/, 6X, 'FAN HORSEPOWER, bhp:', T60, F8.1)
WRITE (i, 220) WT, W
FORMAT (6X,'AIR-COOLER WEIGHT, Ib:', T60, F9.1, /, 6X,
'TUBE BUNDLE WIDTH, ft.:',T60,F8.1)
WRITE (i, 230)
FORMAT (IH ,78(IH-))
FORM FEED THE PRINTING PAPER TO TOP OF THE NEXT PAGE.
WRITE (i, *) CHAR(12)
CLOSE (3, STATUS='KEEP')
CLOSE (i)
STOP
END
715
PROGRAM PROG85
HEAT-TRACER REQUIREMENTS FOR PIPELINES.
THE PROGRAM CALCULATES THE HEAT LOSS AND TRACING REQUIREMENTS
FOR ANY GIVEN PIPELINE USING HOT OIL OR SOME OTHER HOT FLUID
MEDIUM AS THE HEAT SOURCE. IT ALSO CALCULATES THE HEAT LOSS
FROM AN INSULATED PIPELINE WITHOUT A HEAT TRACER.
THIS PROGRAM WILL CALCULATE:
I. SURFACE TEMPERATURE OF INSULATED TRACED PIPE.
2. TOTAL HEAT TRANSFERRED PER i00 ft. OF PIPE.
3. TOTAL HEAT TRANSFERRED FOR ENTIRE PIPELINE.
4. FLOW RATE FOR HOT MEDIA.
5. TOTAL NUMBER OF HEAT TRACERS REQUIRED WITH AND WITHOUT
TRANSFER CEMENT.
HEAT TRANSFERRED THROUGH AN INSULATED PIPE ENCOUNTERS FOUR
RESISTANCES:
i. FILM RESISTANCE ON THE INSIDE WALL OF THE PIPE.
2. HEAT RESISTANCE THROUGH THE PIPE WALL.
3. HEAT RESISTANCE THROUGH THE INSULATION.
4. AIR-FILM RESISTANCE ON THE OUTSIDE OF THE INSULATION.
HOWEVER, THE FIRST TWO RESISTANCES, i. AND 2. ARE NORMALLY
VERY SMALL AND ARE THEREFORE NEGLIGIBLE IN THIS PROGRAM.
TMEDAV = AVERAGE TEMPERATURE OF HOT MEDIUM, oF.
TMI = HOT-MEDIUM INLET TEMPERATURE, oF.
TMO = HOT-MEDIUM OUTLET TEMPERATURE, oF.
TAVG = AVERAGE TEMPERATURE OF PIPE AND TRACER, oF.
DI = INSIDE DIAMETER OF INSULATION, in.
OD = OUTSIDE DIAMETER OF PIPE, in.
TAL = ALLOWANCE FOR TRACER DIAMETER, in.
DOS = OUTSIDE DIAMETER OF INSULATION, in.
TK = INSULATION THICKNESS, in.
Q = HEAT LOSS PER FOOT OF PIPE, Btu/hr.ft.
KINS = THERMAL CONDUCTIVITY OF INSULATION, Btu/hr.ft^2.(oF/ft).
TS = OUTSIDE SURFACE TEMPERATURE OF INSULATION, oF.
HA = FILM HEAT-TRANSFER COEFFICIENT TO AIR CORRECTED
FOR THE WIND, Btu/hr.ftA2.oF.
TAIR = AIR TEMPERATURE, oF.
HCOMB = HC+HR: COMBINED CONVECTIVE AND RADIATIVE HEAT TRANSFER
CO-EFFICIENT, Btu/hr.ft^2.oF.
WF = WIND FACTOR.
QT = TOTAL HEAT LOSS FROM PIPELINE, Btu/hr.
W = FLOW RATE OF HOT MEDIUM, ib/hr.
TOTL = TOTAL PIPELINE LENGTH, ft.
CP = SPECIFIC HEAT OF HOT MEDIUM, Btu/ib.oF.
TWOC = NUMBER OF TRACERS REQUIRED WITHOUT HEAT-TRANSFER CEMENT.
TCA = THERMAL CONDUCTANCE, TRACER TO PIPE
WITHOUT CEMENT, Btu/hr.oF(ft of pipe).
TWC = NUMBER OF TRACERS REQUIRED WITH HEAT TRANSFER CEMENT.
TCB = THERMAL CONDUCTANCE, TRACER TO PIPE
WITH CEMENT, Btu/hr.oF(ft of pipe).
TP = TEMPERATURE IN THE PIPE, oF.
***************************************************************
716