MODERNIZATION OF STEAM GENERATORS

Transcription

1 MODERNIZATION OF STEAM GENERATORS 341-G-004 & 341-G -005 in Rijeka Refinery Energy Plant by consumption of natural gas Opatija Svetlana Petrović, Mag.ing.mech; Univ.spec.oec.

2 Rijeka Refinery Utility System Energy Plant Boilers Turbogenerators Electrical Power System Large Combustion Plant directive 2001/80/EC Emission limit values laid down in part A of Annexes III to VII in respect of sulphur dioxide, nitrogen oxides and dust are respected. Some existing power plants had a derogation which provided them with 2 options to comply with the Direktive: either to operate only a limited number of hours or to be upgraded. The model selected between the two options on a case by case basis. The upgrading is reflected through higher capital costs. IPPC Directive 2008/1/EC Costs of filters and other devices necessary for compliance are reflected in the parameters of the model

3 Steam and Electrical Power Production 341-T26

4 Energy plant (Steam production)

5 Energy Plant High pressure steam (37 bar g ; 450 C) Production on four steam boilers G-001 (2005) 40/50 t/h (nom/max) G-002 (2005) 40/50 t/h G-004 (1977) 80/100 t/h G-005 (1980) 80/100 t/h G-003 (1968) Out of service! Steam production 240 t/h Steam boilers efficiency (average) 91%

6 Steam Production Middle pressure steam MPS (13 bar g ; 280 C) production on: - Steam extraction turbines 341-T- 010 (16 t/h) 341-T- 021 (100 t/h) - Steam pressure reduction station Low pressure steam LPS (5 bar g ; 200 C) - Steam extraction turbine 341-T- 010 (45 t/h) - Steam pressure reduction station

7 Technical description (G1/G2) 1.1.Steam boilers 341-G001/G002 installed: producer: Đ.Đ. TEP (Croatia) number of burners: 2 per boiler type: DYNASWIRL medium for dispersion: steam steam pressure: 6 bar g

8 Technical description (G1/G2) steam temp.: 280ºC pressure of inlet fuel oil: 12/14 bar g viscosity: 15/20 cst temp. of inlet oil: 135 ºC max temp. of combustion air: 100 ºC pressure of inlet fuel gas: 1 bar g air glut (λ): 1.05 for fuel gas 1.1 for fuel oil

9 Technical description (G1/G2) Max. capacity for lighting per burner: 2460 Nm 3 /h for fuel gas 2040 kg/h for fuel oil Capacity of fuel oil station: 15m 3 /h Heating power: 32.8 MW

10 Technical description (G4/G5) 2.1.Steam boilers 341-G004/G005 installed: and producer: Đ.Đ. (Croatia) number of burners: 4 per boiler type: LMF medium for dispersion: steam steam pressure: 13 bar g

11 Technical description (G4/G5) steam temp.: 280ºC pressure of inlet fuel oil: 14/15 barg viscosity: 15/20 cst temp. of inlet oil: 135 ºC max temp. of combustion air: 100 ºC pressure of inlet fuel gas: 1 barg air glut (λ): 1.05 for fuel gas 1.1 for fuel oil

12 Technical description (G4/G5) Max. capacity for lighting per burner: 2050 Nm 3 /h for fuel gas 1850 kg/h for fuel oil Capacity of fuel oil station: 15m 3 /h Heating power: 77 MW

13 Steam Production Problems Low quality liquid fuel (high content of sulphur and heavy metals vanadium, nickel) causes: - Hard deposits on the fire side surface of the steam boilers day cleaning intervals (out of service for 7 days) - High temperature corrosion of steam boiler superheaters - Increased SO 2, NO X and particle emission - High maintenance cost - Reduced reliability and availability of the steam boilers (steam boiler 341-G-003 out of service -inspection veto: TK /ŽB)

14 Combustion Fuel oil + Refinery gas Burners - Combined (Fuel oil + Refinery gas) - Proportion of combustion (10-100%) - Burner types G 001/G John Zink (low NOX) G 004/G LMF Austria

15 Emissions of harmful substances into the environment (boilers > 50 MW); ISO ) fuel type fuel oil fuel gas rigid (solid) particles < 50 mg/m3 < 5 mg/m3 CO < 175 mg/m3 < 100 mg/m3 NOx < 450 mg/m3 < 300 mg/m3 SO2 < 1700 mg/m3 < 800 mg/m3

16 Emissions of harmful substances into the environment; G4 and G5 G4 G5 GVE date fuel type fuel oil fuel oil oxygen 2.7% 1.7% flue gases temp. 225 ºC 215 ºC SO (5100) CO (525) solid particles (150) NOx (1350) smoke number 0 0

17 Emissions of harmful substances into the environment; G1 and G2 (< 50MW) G1 G2 GVE date fuel type fuel oil fuel oil oxygen 2.8 % 3.0 % flue gases temp ºC ºC SO (5100) CO (525) solid particles (150) NOx (1350) smoke number 0 0

18 Boiler deposits

19 Boiler deposits, analysis Ashing results: loss at 500 ºC 5% loss at 925 ºC 22%

20 Boiler deposits, analysis; elemental analysis by X-ray sodium 3 % magnesium 3 % aluminium 5 % silicon 6 % Sulphur 18 % Calcium 1 % Vanadium 42 % Iron 7 % Nical 8 % Zink < 1 % Arsenic < 1 % total oxides (to loss at 500ºC) 95 % ph of a 1% of slurry 2.8 %

21 Necessary Investments (steam boilers) Natural gas supply system. Natural gas is also used for firing steam boilers. Exchange and modernization of burner system for steam boilers 341-G-004 and 341-G-005 Exchange and modernization of control system (measurement, regulation and protection) for steam boilers 341-G-004 and 341-G- 005 Replacement of steam boiler 341-G-003 due to inspection veto: TK /ŽB)

22 Necessary Investments (boilers) 2 General remount /replacement of damaged parts on G4/G5 boilers Periodically burners service (once in two years) by burners producers Installation of NH4OH injection into combustion chamber Reconstruction of fuel-oil stations Installation of on-line monitoring for CO2 and NOx Additives treatment for fuel-oil

23 Operational issues Steam generators use heavy fuel oil un sustained quality and work constantly throughout the year with changing load. Fatigue problems in their work is derived solely from fuel or its poor quality (increased content of vanadium, nickel and sulfur), and can in principle be defined as: Increased content of uncompleted burned out particles in the exit flue gas, Creation of the dregs of the heating surfaces (hard to clean) in containers and fuel pipelines, Appearance of high-corrosion (on steam heaters) caused by the creation of low soluble eutectic (vanadium oxides), High content of SO3 in the flue gas output, The presence of low temperature corrosion in some parts of steam generators,

24 Fuel feeds for the steam boilers depends on RR Modernization status: Existing RR: 100% Fuel Oil; After the 1st Phase of Modernization: 60% Natural Gas & 40% Fuel Oil; After the 2nd Phase of Modernization: 100% Natural Gas.

25 Case 1 - Rijeka Refinery 1st Phase of Modernization - without TA4 Cost Calculation The HP and MP steam that is available from 1st Phase of RR Modernization process units is calculated in the model with price 0.0 HRK/t because the steam is surplus in HGU and HCU. Under normal operation 13.5 MW EP is purchased from HEP: MHRK/Mo. Under normal operation all EP purchase from HEP: MHRK/Mo. Normal operation Model optimization: MHRK/Mo. - A boundary defined to be turbogenerators in operation. Otherwise the minimum cost is when all EP was purchased from HEP. RR PP EP price is lower than HEP EP price because of free steam from HGU and HCU units: RR PP EP price: HRK/kWh RR steam prices**: HP steam = HRK/t HEP EP with PPL: HRK/kWh MP steam = HRK/t HEP EP price: HRK/kWh LP steam = HRK/t In the case of unplanned stoppage of steam boilers (-80 t/h and -40 t/h) because of PPL and week EP purchase: - Operation 80 t/h: MHRK/Mo. (No need to purchase EP from HEP!) - Operation -120t/h with RUS: MHRK/Mo. (No need to purchase EP from HEP!) - Operation -120t/h with G3: MHRK/Mo. (No need to purchase EP from HEP!)

26 First possibility (explain by now in the presentation) 1. Upgrade existing INA RR Power Plant with: i. Replacement of the G3 steam Boiler: Capacity: 80/100 t/h (nom/max) High Pressure Steam: 37bar/450 C Cost of investment: ~100.0 Mil HRK (18.5 Mil $) ii. A new substation TS-400: 2 x 63 MVA 110/35 kv Cost of investment: ~ Mil HRK (18.5 Mil $) iii. Modernistion of G4 / G5 steam Bolier : Capacity: 2 x 80/100 t/h (nom/max) High Pressure Steam: 37bar/450 C Cost of investment: ~50.0 Mil HRK (9 Mil $)

27 Other possibilities 2. Build a new Power Plant in Rijeka Refinery + New PP on a new location in RR (far from sea side and closed type building) + More reliable solution (new steam boiler and new turbogenerators) - High investment cost (but cost estimation does not exist) - Hard to justify the investment because of ongoing projects: The new turbogenerator TA-4 is under construction, Other projects in Power Plant (are going to be done during Turnaround 2010 or in 1st Phase of RR Modernization) - Long time needed to begin the project (government permissions, )

28 HEP TE Rijeka location

29 HEP TE Rijeka General data: location: type of power plant: type of fuel: total capacity: type of product: south-east of Rijeka, on the sea coast regulating/condensing, a boiler and one steam turbine oil 320 MW electricity year of construction: annual production electricity ~1000 GWh/year

30 Conclusions Existing Energy Supply Strategy for INA RR 1. Upgrade existing INA RR Power Plant: Goal: To secure enough Energy supply for Rijeka Refinery ( II Phase of Modernization ) Here are main two options that depend on required level of RR Energy Independency (To secure Energy supply)

31 Conclusion no. 1.1 Existing Energy Supply Strategy for INA RR? 1.1 INA RR complete energy independence with having full energy demand backup from outside: For steam 80/100 t/h surplus in own RR Power Plant production Modernisation of G4 and G5 boilers The new G3 steam boiler is necessary For electricity in incomers 63 MVA. The new substation TS-400 is necessary Secure feed fuels for steam boilers Alternate fuels existing in RR: oil, refinery gas, or Natural Gas (NG) inside of RR - done

32 Conclusion no. 1.2 Existing Energy Supply Strategy for INA RR? 1.2 INA RR fully dependent on outside energy supply with having part of capacity backup in own existing production in RR PP: For steam it is necessary to find other outer source (HEP TE Power Plant Rijeka) The new steam pipeline to HEP Power Plant Rijeka investigate!) (an option to be Existing steam boilers will exists as partial backup For electricity in incomers 63 MVA. The new substation TS-400 is an option, second A new incomers directly from HEP TE Power Plant Rijeka option to be investigate!) (an Secure feed fuels for steam boilers Highly dependent on Natural Gas from outside of RR