Steam turbine in Geothermal Power Station

Steam turbine in Geothermal Power

Station

Presented by:S. Ady Candra

Post Graduate Certificate in Geothermal Energy Technology

Flow Diagram Conventional Thermal Power Plant

Main Equipments1. Boiler and auxiliary Equipment 2. Steam Turbine and Auxiliary

Equipment3. Condenser and Cooling

System 4. Feed Water Heating Plant 5. Chemical Feed System

Balance of plant1. Waste Water & De-mineralized water Plant2. Fire Protection System 3. Compressed Air System 4. Fuel & Material Handling System 5. Sampling Rack System 6. Laboratory Equipment 7. Hoist Auxiliary Utility Devices 8. Workshop and Machinery Equipment

Flow Diagram Geothermal Power Station (Pohipi )

Main System1. Bore /Steam field2. Separator/Flash Plant3. Steam treatment (scrubber)

If needed4. Steam Turbine and

Auxiliary Equipment5. Condenser and Cooling

System 6. Chemical Feed System If

needed7. NCG Removal and

treatment 8. Reinjection System

Steam Turbine and Auxiliary Equipment1.Lubricating system2.Lubricating Oil cooling

system3.Crane & hoist system

Condenser and Cooling System 1.Condenser2.Condensate & Cooling

water pumps3.Cooling tower or one

through system

The same item between thermal & Geothermal Power plant

Type of steam turbine : Exhaust conditions

◦ Non condensing (back pressure)

◦ Full condensing Flow designation

◦ Single or double flow Pressure-reheat

designation

Type of steam turbines

Extraction types (pass out)Number of inlet steam (pass in)

Shaft orientation(Tandem and cross compound)

Exhaust condensing orientation(Downward, over upward & axial )

Main consideration◦Steam properties◦Pressure & Temperature of steam

◦Material of steam turbine Casing Shaft Blade

Design and selecting of steam turbine for geothermal Power Plant

Common design construction of steam turbine-generator set Downward

condensing Steam turbine

Axial Exhaust Design Of Steam Turbine

New Design Arrangement of Steam Turbine-generator set

PerformanceTurbine buildingPeriod for site erection work

Comparison of Axial & Downward Steam Turbine

Axial exhaust turbines offer reduced exhaust loss and greater efficiency as compared to upward and downward exhaust turbines.

Performance

Downward exhaust Axial exhaust

Turbine building

Axial Exhaust turbine•Above-ground foundation concrete reduced by 30%.

•Total building floor area reduced by 75% and total volume by 67%

Axial exhaust turbines require less foundation concrete and a smaller building, thereby reducing both the cost and the lead time of construction.

Axial exhaust turbines reduce the cost of maintenance and the space required in which to perform it.

Period for site erection work

Hellisheidi Geothermal Power Station, Iceland

Geothermal power station with Axial exhaust Steam turbine

Type of plant Single flash, condensing Rated output 40 x 2 units (MW) Steam conditions• Pressure 0.75 (MPa) •Temperature 167.8 (oC) Exhaust pressure (MPa abs.) 0.01

Type of turbine SC1F-30 AX "(Single-cylinder, single flow, impulse-reaction axial exhaust condensing turbine)

Exhaust type Axial exhaust Rated speed 3 000 (rpm)Number of stages 6Last blade height 762 mmType of condenser Shell & tube (surface cooling type) Type of cooling tower Mechanical draft, counter flow

Turbine floor Hellisheidi geothermal Power Station

Black & Veatch, 1996, Power plant engineering, Springer Science+Business Media, Inc.

Condensing Multistage Axial Exhaust Steam Turbine, 2012. Retrieved from http://www.snm.co.jp/products/turbines/fukusui_02.html

Nagasaki Shipyard & Machinery Works, 2007, A New Geothermal Steam Turbine with a "Single-Cylinder Axial Exhaust Design" (Outline of the Hellisheidi Geothermal Turbine in Iceland), Technical Review Vol. 44 No. 4. Mitsubishi Heavy Industries, Ltd.

References list

Thanks