Cost Savings through Energy Audit Quantifying the Potential for Improvement

Transcription

1 Cost Savings through Energy Audit Quantifying the Potential for Improvement 22 May

2 Potential Plant Improvements

3 Fresh BFW Operational Adjust - Waste Heat Boiler Optimization Set point = 160 C Steam drum Recirculation 120 C 230 C

4 Operational Adjust - Waste Heat Boiler Optimization Acid Dew Point degc Acid Dew Point vs H2S in Fuel Gas Source : Gatecycle Verhoff-Banchero correlation (based on Fuel Gas with 76 mol% H2) ppm H2S in fuel gas

5 Operational Adjust - Waste Heat Boiler Optimization Thermodynamic model of the waste heat boiler was used to predict the improvement of heat recovery as inlet BFW temp is lowered Oleflex Heater Stack Temp & HPS Flow vs Flue Gas Flow For Varying Econ inlet BFW Temp (TIC2018) T stack (Deg C) T Stack (Deg C) HPS Flow (T/H) HPS (T/H) T Stack (177) T Stack (160) T Stack (140) T Stack (121) HPS (177) HPS (160) HPS (140) HPS (121) Flue Gas Flow (T/HR) 10.0

6 Operational Adjust - Waste Heat Boiler Optimization Adjustment of the Operating setpoint for Inlet BFW Temperature TC2081 achieved a drop in Stack Temperature and a 1 T/H increase in HP steam production EB220 Performance Testrun TI2094 TC TI2094 DegC TC2081 DegC /27/2008 2/3/2008 2/10/2008 2/17/2008 2/24/2008 3/2/2008 3/9/2008 3/16/2008

7 Ethylene Plant Cracked Gas Compressor Poor performance of compressor Cracking furnaces fired with high excess O2 to enable more Super High Pressure Steam generation to drive Steam Turbine Limiting Plant Intake Poor energy efficiency

8 CGC limiting intake < 90% maximum Excessive Steam Consumption of Steam Turbine > 20% Main culprit suspected Balance Line Recycle flow F F F F Balance Line HP Steam Charge Gas Stage 1 Stage 2 Stage 3 Stage 4 Steam Turbine Condenser 1 st Intercooler 2 nd Intercooler 3 rd Intercooler

9 Simulation model of Compressor and Steam Turbine used to calculate current performance based on testrun data

10 Expected performance of the compressor is calculated using compressor simulation model tuned to compressor design performance curve Performance Curve Compressor Map Design performance curve parameter is valid for the rated suction condition. The same is corrected to get the compressor map. Inlet Flow, Inlet Pressure, Inlet Temperature, Outlet Pressure, Compressor Speed Inputs New & Clean GateCycle Compressor Outputs New & Clean Compressor Power, Outlet Temperature

11 24 CGC Power Break-Down (MW) CGC New & Clean 16 Compressor Power MW

12 24 CGC Power Break-Down (MW) CGC Extra Power Consumption due 1.6 MW to 4 th / 3 rd Stage Balance-Line Leakage CGC New & Clean 16 Compressor Power MW

13 24 CGC Power Break-Down (MW) CGC 1 st Stage Inefficiency CGC Extra Power Consumption due 1.6 MW to 4 th / 3 rd Stage Balance-Line Leakage CGC New & Clean 16 Compressor Power MW

14 24 CGC Power Break-Down (MW) CGC 2 nd Stage Inefficiency CGC 1 st Stage Inefficiency CGC Extra Power Consumption due 1.6 MW to 4 th / 3 rd Stage Balance-Line Leakage CGC New & Clean 16 Compressor Power MW

15 24 CGC Power Break-Down (MW) CGC 3 rd Stage Inefficiency CGC 2 nd Stage Inefficiency CGC 1 st Stage Inefficiency CGC Extra Power Consumption due 1.6 MW to 4 th / 3 rd Stage Balance-Line Leakage CGC New & Clean 16 Compressor Power MW

16 24 CGC Power Break-Down (MW) CGC 4 th Stage Inefficiency CGC 3 rd Stage Inefficiency CGC 2 nd Stage Inefficiency CGC 1 st Stage Inefficiency CGC Extra Power Consumption due 1.6 MW to 4 th / 3 rd Stage Balance-Line Leakage CGC New & Clean 16 Compressor Power MW

17 24 CGC Power Break-Down (MW) CGC 4 th Stage Inefficiency CGC 3 rd Stage Inefficiency CGC 2 nd Stage Inefficiency CGC 1 st Stage Inefficiency CGC Extra Power Consumption due 1.6 MW to 4 th / 3 rd Stage Balance-Line Leakage Steam Turbine Actual Power CGC New & Clean 16 Compressor Power MW Steam Turbine Power MW

18 24 CGC Power Break-Down (MW) CGC 4 th Stage Inefficiency MW Steam Turbine Loss due to Condenser Vacuum CGC 3 rd Stage Inefficiency CGC 2 nd Stage Inefficiency CGC 1 st Stage Inefficiency CGC Extra Power Consumption due 1.6 MW to 4 th / 3 rd Stage Balance-Line Leakage Steam Turbine Actual Power CGC New & Clean 16 Compressor Power MW Steam Turbine Power MW

19 24 CGC Power Break-Down (MW) CGC 4 th Stage Inefficiency MW Steam Turbine Internal Losses Steam Turbine Loss due to Condenser Vacuum CGC 3 rd Stage Inefficiency CGC 2 nd Stage Inefficiency CGC 1 st Stage Inefficiency CGC Extra Power Consumption due 1.6 MW to 4 th / 3 rd Stage Balance-Line Leakage Steam Turbine Actual Power CGC New & Clean 16 Compressor Power MW Steam Turbine Power MW

20 CGC Power Break-Down (MW) MW Total Steam Turbine Losses MW Total Compressor Losses MW Compressor Power MW Steam Turbine Power MW

21 24 CGC Power Break-Down (MW) Potential Available Shaft Power for Plant Intake Increase MW MW Compressor Power MW Steam Turbine Power MW

22 Heavy sticky polymerisation Overall increase in fouling in each stage from LP to HP LP 2 nd stage discharge volute seized

23 Balance piston seal upper side lead lining peel off More than half portion of lead lining gone & lost Suspected main culprit of CGC internal circulation

24 Full recovery of the Compressor Performance after total Overhaul of Compressor and ST Condenser 5 MW shaft power or 15 MW fuel energy savings Initial troubleshooting focused only on Balance Line recycling Complete Heat Balance analysis showed degradation of compressor stages and ST / Condenser Analysis technique provides a more thorough diagnosis of all losses in order to avoid in-complete repairs Loss of Energy Efficiency due to Equipment Degradation cannot be underestimated!!

25 Retrofit Improvement - CDU Heat Integration Petronas Refinery Crude Distillation Unit Crude Preheat Train Replacement of Shell & Tube HX by Alfa Laval Welded Parallel Plate Compablocs Process Simulations and Hydraulic Calculations Furnace fuel savings by increasing Furnace Inlet Temp

26 Retrofit Improvement - CDU Heat Integration Advantage of Welded Parallel Plate HX over Shell and Tube Compact and light weight 4000 m 2 S&T = 850 m 2 PPHX fits in 2,9 m 2 plot space 5-10 x less flooded weight High energy efficiency Temperature approach of 3-5 C 3-5 x higher heat transfer efficiency Low fouling tendency & easy to clean 3 times longer operating period inbetween maintenance 1-3 days of down-time for cleaning Corrosion-free material, no inter-plate gaskets

27 Pre-flasher Retrofit Improvement - CDU Heat Integration 50 kbbl/d Desalter HS Legend: Preflash OVHD Kero Prod Kero PA Diesel Diesel PA LSWR 233 deg C PROPRIETARY INFORMATION 27

28 Pre-flasher C-116 Retrofit Improvement - CDU Heat Integration 50 kbbl/d 39 deg C 67 deg C 93 deg C 98.5 deg C 131 deg C Desalter E137B E105C E139B E142C HS Legend: Preflash OVHD Kero Prod Kero PA Diesel Diesel PA LSWR 251 deg C 225 deg C 201 deg C 112 A/B 150 deg C 108 A/B E140B 229 deg C E141B E136B 208 deg C PROPRIETARY INFORMATION 28

29 Retrofit Improvement - CDU Heat Integration Furnace Inlet Temp 260 degc 255 Start-up Last cycle before project commissioning /10/ /11/ /12/ /1/ /2/ /3/ /4/ /5/2013 Alfa Laval Slide 29

30 Retrofit Improvement - CDU Heat Integration Project pay-pack calculation Compabloc cost (6 items), kusd Total project cost, kusd Max production, kusd* Avoiding throughput decline of 15% at EOR Uptime savings, kusd*: Avoiding shut-down every 10 months for 10 days Energy savings, kusd*: Raising CIT from 233 -> 251 degc Total savings, kusd Project pay-back time 21 months * Assuming furnace fuel cost of 40 USD/bbl and refinery margin of 50 cents/bbl

31 Thank You COMPRESSOR WORK (.% of GT Shaft Power) INLET AIR (1.45%) CHEMICAL ENERGY (97.32%) FUEL SENSIBLE HEAT 1.00% ROTOR COOLING LOSS (2.09%) COMBUSTOR LOSS (0.49%) AUXILIARY POWER (0.22%) GT SHAFT POWER (34.23%) DUCT LOSS (0.35%) RADIATION LOSS (0.34%) HP STEAM (34.39%) HP TURB POWER (2.18%) IP STEAM (8.6%) PIPE LOSS (0.08%) SHAFT POWER IP TURB POWER (6.68%) LP TURB POWER (10.87%) CONDENSER LOSS 33.53% RADIATION LOSS (0.06%) RADIATION LOSS (0.09%) RADIATION LOSS (0.04%) LP STEAM (4.03%) STACK LOSS (8.97%)