Wear of geothermal turbine. Sæmundur Guðlaugsson
ON
Presentation subject
1. ON Power
2. Maintenances plan
3. Main machinery parts of Turbine
4. Main wear problem and planning and development.
5. Conclusion
Reykjavík Energy
Group Reykjavík Energy is owned by three municipalities: The city of
Reykjavik, Akranes and Borgarnes.
ON Power: Production and sales of electricity and hot water.
OR Utilities: Distribution of electricity, hot water, cold water
and runs the sewage systems.
GR Fibernet: Operates a fiber optic network
Power Plants
Hellisheiði Geothermal Power plants
Nesjavellir Geothermal Power Plants
Andakílsárvirkjun Hydro power plant
Capacity of 8 MWe
Hellisheiði Power Plants 2006
Combined Heat and Power plant
303 MWe of electricity and133 MWth of thermal
Nesjavellir Power Plant 1990
Combined Heat and Power plant
Commissioned : 2005 (newest
part)
120 MWe of electricity and 300 MWth of thermal
ON Power
36 boreholes for Hellisheiði Power Plants 19 boreholes for Nesjavellir Power Plants Nesjavellir 240 kg/s Hellisheiði 480 kg/s
Maintenances plan
» After two years of running, turbines is stop in one week for inspection,
electrical inspections along with views of auxiliary equipment and cleaning
of the cooling tower
» After four years of running, turbines is stop in three weeks for overhauling
» After twelve years overhauling of the generators
Overhaul of geothermal turbine
» Replacement of defective parts
» Cleaning parts
»Repair worn parts
» NDT inspection of rotors
» Settings of diaphragm
» Measurement of seals
»Assemble
Machinery parts of Turbine
Main wear problem planning and development
Dissolution of seats for the diaphragm
The stem and woter is flow under the diaphragm an is cut the set and the diaphragm
Repair the wear of seats for the diaphragm
Milling for the 304 strip
strips fixed by welding
The seat in the casing is grinding
down of 2mm and welded with 309
Mo wire
Dissolution between blades on the diaphragm
The steam has
excavated down into material
Dissolution between blades on the diaphragm
•The steam has engraved into
the material
•Welding wire ER309Mo or D-10 Ni base 182 Nickel Base Alloys.
Welding near the blade
Special holder for diaphragm designed for welding
CMT welding for the diaphragm
» CMT stands for Cold Metal Transfer
» Reduced heat exposure to the material that is being welding
» Reduced mixing of the base material in the welding string
» The risk of deformation will be lower
Before repair Surface welded with stainless wire ER309Mo After 2mm metal processing Final metal working
After repair 2mm stainless coating on surface assembly.
Repair of dissolution in assembly surfaces
Dissolution in the casing bottom
Improvements of drain water from engine
Condensate water
drains directly from
steps and drains
increased.
Dissolution of the rotor
Dissolution of the balance hole and connection point
for the blade.
Dissolution of the last blade
Turbine axle worn.
Our method now:
Mille down 5mm
and welde with
Inconel wire..
heat treatment
Repair of turbine blades
Wear gap in blade
Material in the blade
AISI 630
Rotor workshop in Hellisheiði Power Plants
Invested in:
Balance unit
Lathe
Welding unit
PWHT equipment
NDT equipment
Rotor repair example
Repair and provides components in geothermal
turbines ON
Conclusion
» Lower spare parts prices
» Lower the cost of repair of turbine components
» High quality work on repairs based on what was known from foreign
suppliers.
» Raises the level of technology in the country
» increases operational reliability
» Creates jobs in the country
» We estimate when wee have used this repair technology for all of our units
it will be possibility extended between the overhauling from four years to
five or six years.
Conclusion
» Lower spare parts prices
» Lower the cost of repair of turbine components
» High quality work on repairs based on what was known from foreign
suppliers.
» Increase the knowledge of repair techniques in the country
» Increases operational reliability
» Creates jobs in the country
» Saves currency
» Because of this repair development it will be possible to extend between
owerholing of units from four years 5 to 6 years when we have finished a
overhaul of our machines with this techniques.
Foresight-Efficiency-Integrity
Thank you