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MODERNIZATION OF

STEAM GENERATORS

341-G-004 & 341-G -005

in Rijeka Refinery Energy Plant

by consumption of natural gas

Opatija 2012.

Svetlana Petrović, Mag.ing.mech; Univ.spec.oec.

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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

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Steam and Electrical Power Production

341-T26

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Energy plant (Steam production)

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Energy Plant

High pressure steam (37 barg; 450 C)

Production on four steam boilers

- 341-G-001 (2005) 40/50 t/h (nom/max)

- 341-G-002 (2005) 40/50 t/h

- 341-G-004 (1977) 80/100 t/h

- 341-G-005 (1980) 80/100 t/h

- 341-G-003 (1968) Out of service !

Steam production 240 t/h

Steam boilers efficiency (average) 91%

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Steam Production

Middle pressure steam MPS (13 barg; 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 barg; 200 C)

- Steam extraction turbine

341-T- 010 (45 t/h)

- Steam pressure reduction station

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Technical description (G1/G2)

1.1.Steam boilers 341-G001/G002

installed: 2005.

producer: Đ.Đ. TEP (Croatia)

number of burners: 2 per boiler

type: DYNASWIRL

medium for dispersion: steam

steam pressure: 6 barg

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Technical description (G1/G2)

steam temp.: 280ºC

pressure of inlet fuel oil: 12/14 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

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Max. capacity for lighting per burner:

2460 Nm3/h for fuel gas

2040 kg/h for fuel oil

Capacity of fuel oil station: 15m3/h

Heating power: 32.8 MW

Technical description (G1/G2)

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Technical description (G4/G5)

2.1.Steam boilers 341-G004/G005

installed: 1977. and 1980.

producer: Đ.Đ. (Croatia)

number of burners: 4 per boiler

type: LMF

medium for dispersion: steam

steam pressure: 13 barg

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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

Technical description (G4/G5)

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Technical description (G4/G5)

Max. capacity for lighting per burner:

2050 Nm3/h for fuel gas

1850 kg/h for fuel oil

Capacity of fuel oil station: 15m3/h

Heating power: 77 MW

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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

- 100 day cleaning intervals (out of service for 7 days)

- High temperature corrosion of steam boiler superheaters

- Increased SO2, NOX 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 073-2007/ŽB)

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Combustion

Fuel oil + Refinery gas

Burners

- Combined (Fuel oil + Refinery gas)

- Proportion of combustion (10-100%)

- Burner types

- 341-G 001/G 002 - John Zink (low NOX)

- 341-G 004/G 005 - LMF Austria

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Emissions of harmful substances into the environment

(boilers > 50 MW); ISO 10396-1997)

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

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G4 G5 GVE

date 19.11.2008. 19.11.2008.

fuel type fuel oil fuel oil

oxygen 2.7% 1.7%

flue gases temp. 225 ºC 215 ºC

SO2 3377 4051 1700(5100)

CO 7 9 175(525)

solid particles 81.77 72.28 50(150)

NOx 775 699 450(1350)

smoke number 0 0

Emissions of harmful substances into the environment; G4 and G5

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Emissions of harmful substances into the environment; G1 and

G2 (< 50MW)

G1 G2 GVE

date 05.11.2008. 05.11.2008.

fuel type fuel oil fuel oil

oxygen 2.8 % 3.0 %

flue gases temp. 211.5 ºC 207.3 ºC

SO2 3223 3287 1700(5100)

CO 1 0 175(525)

solid particles 66.80 66.11 50(150)

NOx 615 681 450(1350)

smoke number 0 0

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Boiler deposits

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Boiler deposits, analysis

Ashing results:

loss at 500 ºC 5%

loss at 925 ºC 22%

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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 %

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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

073-2007/ŽB)

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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

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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,

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- || -

9. 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.

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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: 21.024 MHRK/Mo.

Under normal operation all EP purchase from HEP: 16.878 MHRK/Mo.

Normal operation Model optimization: 19.988 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: 0.4141 HRK/kWh RR steam prices**: HP steam = 133.97 HRK/t

HEP EP with PPL: 0.6326 HRK/kWh MP steam = 120.51 HRK/t

HEP EP price: 0.4730 HRK/kWh LP steam = 117.05 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: + 0.0 MHRK/Mo. (No need to purchase EP from HEP!)

- Operation -120t/h with RUS: + 0.0 MHRK/Mo. (No need to purchase EP from HEP!)

- Operation -120t/h with G3: + 0.0 MHRK/Mo. (No need to purchase EP from HEP!)

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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: ~ 100.0 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 $)

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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,…)

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HEP TE Rijeka location

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HEP TE Rijeka

General data: location: south-east of Rijeka, on the sea coast

type of power plant: regulating/condensing, a boiler and one

steam turbine

type of fuel: oil

total capacity: 320 MW

type of product: electricity

year of construction: 1974 -1978

annual production electricity ~1000 GWh/year

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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)

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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

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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 (an option to be investigate!)

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 (an option to be investigate!)

Secure feed fuels for steam boilers

Highly dependent on Natural Gas from outside of RR