Problem Statement Analysis of Chemical Heat Pump Analysis of Cooling Tower Analysis of Boiler.
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Transcript of Problem Statement Analysis of Chemical Heat Pump Analysis of Cooling Tower Analysis of Boiler.
Problem Statement
Analysis of Chemical Heat Pump
Analysis of Cooling Tower
Analysis of Boiler
Flash tank
Heat exchangerExothermicreactor
Distillation column
endo reactor
Flash tankH2Acetone2-Propanol
H2
condenser
MIXED
Acetone
H2
Acetone2-prop
Compressor 1
Pump 1
Compressor 2
Liquid
gas
Reduction valve
water
Hot airCool air
Pump 2
Air 79 % N2 21 % O2
Natural gas
Combustion gassesCO2, H2O, N2, O2T= 375 F
BFW
SS
CR
BOILER
reboiler
Cooling tower
Ambient air85 F80 % RH
CWR 103 F
Exit air
Pump 3
CWS 75 F
COOLING TOWER
MOCSWORKING DIAGRAMPBL-7-98
WATER
2- prop & acetone
Given: Chemical Heat Pump
Diameter of L1 = 6.35 mm
Average Velocity = 10 m/sec
Temperature L6 = 200 C
Mole composition of L1= .97 2-Propanol
Mole composition of L5= .02 2-Propanol
Given: Chemical Heat Pump (continued)
Hot Air going into Endo 23.8 C
Relative Humidity 80 %
Cool Air coming out of Endo 15.5 C
Required: Chemical Heat Pump
Energy Supplied into Endo Reactor (Qin)
Diameter of L6
Partial Pressures of L6
Amount of Water Condensed in Endo
Endo Reactor
Q in
Hot air
Nextpage
L 202
L 2
L 201
Acetone2- Prop
L 3Condenser
L 5
L 4
L 803
Water
Cool air
L 303
Pump 2
L 1L 101
H2
Re-boiler
Reduction valve
Acetone2-Prop
L 801
CWR
Flash Tank 1
DistillationColumn
Analysis: Chemical Heat Pump (Endo)
Qin = 353000 Btu/ hr (29 ton unit)
Water Condensed 168 lb/hr (21 gal/hr)
Exothermic Reactor
L 202 L 203Compressor 1
L 5Pump 1
ExoReactor
L 6L 501 Acetone
Heat ExchangerL 7
L 802
L 801
Gas
Compressor 2
L 8
L 804
H2
H2
Acetone2-Propanol
Flash Tank 2
H2
Analysis: Exothermic Reactor
Diameter of L6 = 29.0 mm
Partial Pressure: 1.96 ATM Acetone
0.04 ATM 2-Propanol
Given: Cooling Tower
Cold Water Return 39.4 C
Cold Water Supply 23.8 C
Input Ambient Air 29.4 C
Relative Humidity 80 % (Ambient Air)
Exit Air 30.5 C RH 90 %
Given: Cooling Tower (continued)
Diameter for CWS and CWR: 0.05 m
Cooling Tower
CWR103 FCooling
Tower
Ambient Air85 F80 % RH
L 301
L 302
Exit Air
Pump 3
WaterL 303CWS 75 F
Required: Cooling Tower
Velocity for Cold Water Supply
Velocity for Cold Water Return
Pounds of Dry Air from Cooling Tower
Analysis: Cooling Tower
Velocity of Cold Water Supply: 1418.0 m/hr
Velocity of Cold Water Return: 1425.0 m/hr
Pounds of Dry Air: 34,600 lb dry air/ hr
Given: Boiler
Steam Supply 220 psig (q=1)
Cold Return (q=0)
Temperature of Exit Gas 190.5 C
Combustion Gasses: CO2, H2O, N2, O2
Excess Air 40 %
Given: Boiler (continued)
Diameter for SS and CR: .05 m
Boiler
Boiler Feed WaterBoiler
CombustionGassesCO2,H20,N2,O2
L 901L 903
CR
SS
Natural GasAir79 % N221 % O2
T= 375F
L 902
Required: Boiler
Velocity of Steam Supply
Velocity of Cold Return
Flow Rate of Natural Gas
Percent Composition of Exit Gasses
Analysis: Boiler
Velocity Steam Supply: 3960.0 m/hr
Velocity Cold Return: 36.7 m/hr
Amount of Natural Gas: 3.51 tons/month
Analysis: Boiler (continued)
Composition of Flue Gasses:
CO2 = 7.0 %
H20 = 13.9 %
O2 = 5.6 %
N2 = 73.5 %
Differential (Batch) Distillation
Bryan Gipson
John Usher
November 12, 1997
121110987
654321
Feed Pump
Cooler
Distillate
CoolingWater
CoolingWater
Reboiler
Reboiler Pump
Bottoms
CalrodHeater
Condenser
Heater
Feed
ElectromagneticReflux Control
Cooler
Progress
• Familiarization with System
• 2 Runs Conducted– First Run Inconsistent– Second Run Okay
• Data Taken– Initial Volume: 14 liters– Time vs. Temperature– Rate of Distillation
Differential Distillation
71
71.5
72
72.5
73
73.5
74
74.5
75
0 5 10 15 20 25 30 35t, min
T, d
eg
C
Observed
Theoretical
Observations
• Temperature Change– Less than Predicted
• Rate of Distillation– Observed: Sporadic, ~94 ml/min– Theoretical: Decreasing, 215-200 ml/min
Next Steps
• Resolve Inconsistencies
• Conduct More Data Runs
• Estimate Heat Losses
• Compare Column Performance to Predictions
Differential (Batch) Distillation
Bryan Gipson
John Usher
November 12, 1997
121110987
654321
Feed Pump
Cooler
Distillate
CoolingWater
CoolingWater
Reboiler
Reboiler Pump
Bottoms
CalrodHeater
Condenser
Heater
Feed
ElectromagneticReflux Control
Cooler
Progress
• Familiarization with System
• 2 Runs Conducted– First Run Inconsistent– Second Run Okay
• Data Taken– Initial Volume: 14 liters– Time vs. Temperature– Rate of Distillation
Differential Distillation
71
71.5
72
72.5
73
73.5
74
74.5
75
0 5 10 15 20 25 30 35t, min
T, d
eg
C
Observed
Theoretical
Observations
• Temperature Change– Less than Predicted
• Rate of Distillation– Observed: Sporadic, ~94 ml/min– Theoretical: Decreasing, 215-200 ml/min
Next Steps
• Resolve Inconsistencies
• Conduct More Data Runs
• Estimate Heat Losses
• Compare Column Performance to Predictions
Distillation ColumnDesign Project
M. O. C. Project Engineering Department
Team Members
Michael Hobbs
Michael McGann
Marc Moss
Brad Parr
Brian Vandagriff
Topics of Discussion
• Problem Statement
• Recommended Design
• McCabe-Thiele Diagram
• Design Specifications
• Combined Flow Diagram
Topics, cont.
• Method of Design
• Raoult Method
• van Laars Method
• Sieve Tray Efficiency
• Optimum Reflux Ratio
• Conclusions
Problem Statement
To design a new ethylene purification column to work with the advanced catalytic cracking operation that produces ethylene for manufacture of specialty products
PROCESS
AREA B
PROCESS
AREA C
PROCESS
AREA C
EAST AVENUE
WEST AVENUE
BROADWAY
EMPLOYEE PARKING
VISITOR PARKING
OFFICE
T1
T2
T3 T4 FS1
B2
B1
CT1
CT2
T5 T6
CO
LU
MN
ST
RE
ET
ST
RE
ET
3RD
ST
RE
ET
2ND
1ST
DISTILLATE
CWS
SS
Recommended Design
Design analysis included:
• number of trays
• tray diameter
• pipe diameter for each stream
• pump selection (if necessary)
McCabe-Thiele Diagram
Fortran program “Distil.exe” was used to generate data that was plotted in Excel to give McCabe-Thiele Diagram. Diagram shows equilibrium line, operating line, feed line, separation line, and the stepped off stages.
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
x
y
Feed tray = 73
Quantity Description Each Cost System81 23.70 ft. diameter Sieve-trays $4,800.00 $388,800.00
107 ft 8-inch diameter pipe (SS) $175.00 $18,593.75 distillate10 ft 3-inch diameter pipe (SS) $58.00 $580.00 bottoms10 ft 16-inch diameter pipe (SS) $310.00 $3,100.00 feed44 ft 18-inch diameter pipe (SS) $390.00 $17,062.50 CWS63 ft 36-inch diameter pipe (SS) $660.00 $41,250.00 SS100 ft 12-inch diameter pipe (SS) $290.00 $29,000.00 reflux
1 Chemical inline ductile iron casing, vertical motor $1,500.00 $1,500.00 bottoms1 Chemical inline ductile iron casing, horiz. motor $1,800.00 $1,800.00 distillate1 AVS Chemical horizontal ductile iron casing $2,100.00 $2,100.00 reflux
Design Specifications
Combined Flow Diagram
Shows system diagram with both qualitative and quantitative information.
DistillateD = 182 Mlb/hxD = 0.999
Bottoms ProductB = 38 Mlb/hxB = 0.089
Condenser
Splitter
Reboiler
Cold Water Supply = 378.1 Mlb/hT = 80 oF
Steam Supply = 119.7 Mlb/hP = 20 psig
Cold Water ReturnT = 120 oF
Water Return
L = 546 Mlb/h
V’ = 546.5 Mlb/h
L’ = 585.2 Mlb/h
V = 719.5 Mlb/h
FeedF = 220 Mlb/hxF = 0.85f = 1
EM = 80%
81
stages
Design Requirements
• feed : 220 M lb/hr of vapor, 85% ethylene
• product: 182 M lb/hr, 99.9% ethylene
Raoult Model
• Assumes ideal behavior
• System deviated slightly from ideality at low compositions
0.0
0.2
0.4
0.6
0.8
1.0
0.0 0.2 0.4 0.6 0.8 1.0x
y
Actual Data
Operating Line Equilibrium Line
van Laars Model
• Assumes all non-ideal behavior in the liquid
• Shows an improved correlation between model and actual data
0.0
0.2
0.4
0.6
0.8
1.0
0.0 0.2 0.4 0.6 0.8 1.0x
y
Operating Line
Equilibrium Line
Actual Data
Sieve Tray Efficiency
Sieve trays were chosen because they are cheaper, more efficient, and have a larger operating range than other types of tray designs
Fg = Ut g
1/2
Optimum Reflux Ratio
The optimum reflux ratio was determined by calculating the annual operating costs for columns with varying reflux ratios. A plot of annual cost vs. reflux ratio was made; the optimum value is the one that corresponds to the minimum point on the curve.
2.E+06
3.E+06
3.E+06
4.E+06
4.E+06
5.E+06
2.5 3.0 3.5 4.0 4.5 5.0
Reflux Ratio
Annu
al C
ost,
$
Minimizing Annual CostThree options each were given for heating the reboiler and cooling the condenser.
Heating: steam at 20 psig ($1/1000lb)
steam at 100 psig ($3/1000lb)
electrical heating ($0.12/kWh)
Cooling: cooling water ($0.50/1000gal)
domestic water ($1.80/1000gal)
refrigerant ($5/ton-day)
Minimizing Annual Cost
Total annual costs (based on 7200 hr/yr) were calculated for each of the options. The lowest priced option for each was selected.
• heating: steam at 20 psig
• cooling: CWS
Conclusions
The column designed contains 81 trays, with a diameter of 23.7 ft and 12 inch spacing between the trays. It will require an initial start-up cost of $3.01 million, and a present worth of $17.14 million over a projected 11 year operational life.
Ultimate Tennessee Corn whiskey
Skip Pond, EI
Michael McGann
Topics of Discussion
• Past Accomplishments (Section 200)• Current Work (Section 300)• Next Steps
Revised Problem Statement
• Basis: 500,000 gallons finished product
• Areas of focus– Section 200 (Cooking/Fermenting)– Section 300 (Distillation)– Section 900 (Boiler/Cooling Tower)
Revised Problem Statement
• Customer requirements– Operational Schedule Comparison– Automated Control Investigation– Onsite Boiler/Cooling Tower– Pre-Distillation Settling Tank
• Liquid Feed Column with Flash Tank
Section 200: Cooking/Fermenting
Equipment Specifications
No. Item and Description Size Mat'l Const. 1990 unit cost M&S Purchase Price1 S-211Yeast Dry Storage 5000 gal SS 40,000.00$ 0.122 44,880.00$ 2 T-211-212 Mash Tub w/ Bottom Filter(Cooking) 8500 gal. SS 53,528.00$ 0.122 120,116.83$ 7 T-221-227 Fermentation Tank 20000 gal. SS 45,900.00$ 0.122 360,498.60$
1MP-21 Mash Tub Pump and Motor (3/16 SS Centrifugal) 1000 gpm SS 9,216.00$ 0.122 10,340.35$
Total = 535,835.78$
Equipment Specifications for Section 200 (Cooking and Fermentation)
Mash Tank Material Balance
Inputs
• corn: 259 bushels
• rye: 44.3 bushels
• malt: 37.5 bushels
• H2O: 10000 gal.
*1 bushel = 55 pounds
Outputs
• spent grain: 340.8 bushels
• H2Ovap: 2500 gal.
• wort: 7500 gal.
Mash Cooking Energy Balance
qconvectionT, 132oFqx qx
qx + qconvection=1500000Btu/hr
qwater=11293497 Btu/hr
250psia SteamT=401oFh=1202.1 Btu/hr =25,823 lbs/hr
250psia Condensed SteamT=401oFh = 376.02Btu/hr
Heat Exchanger Coils
m
Operational Schedule
DayTank Mon. Tues. Wed. Thurs. Fri. Sat. Sun.T-211 Cook Mash Cook Mash Cook Mash Cook Mash Cook Mash Cook Mash Cook MashT-212 Cook Mash Cook Mash Cook Mash Cook Mash Cook Mash Cook Mash Cook MashT-221 Fill/Ferm Ferment2 Ferment3 Ferment4 Distill Clean IdleT-222 idle Fill/Ferm Ferment2 Ferment3 Ferment4 Distill CleanT-223 Clean Idle Fill/Ferm Ferment2 Ferment3 Ferment4 DistillT-224 Distill Clean Idle Fill/Ferment Ferment2 Ferment3 Ferment4T-225 Ferment4 Distill Clean Idle Fill/Ferm Ferment2 Ferment3T-226 Ferment3 Ferment4 Distill Clean Idle Fill/Ferm Ferment2T-227 Ferment2 Ferment3 Ferment4 Distill Clean Idle Fill/Ferm
Distillation Column
DistillateD = 16 klbxD = 0.55
Bottoms ProductB = 13 klbxB = 0.01
Condenser
Splitter
Reboiler
Cold Water Supply =T =
Steam Supply =P =
Cold Water ReturnT =
Water Return
L =
V’=
L’=
V =
FeedF = 147 klbxF = 0.07f = 1
Tray Spacing = 12 in
EM =11
stages
Feed Tray Material Balance
• L’=RD*D + (1-f)*F
• V’=D*(RD+1) - f*F
Condenser Material Balance
• L=RD*D
• V=D*(RD+1)
Next Steps
• Post Distillation Flash Tank
• Boiler/Cooling Tower Section
• Final cost analysis and reporting