40TH IIEE ANNUAL NATIONAL CONVENTION AND 3E XPO 2015 SMX Convention Center, Mall of Asia Complex, Pasay City

November 25 - 28, 2015

IIEE@40: A Journey of Service for Excellence

Gas Turbine Combined Cycle Power System Technical Presentation by

Engr. Enrique I. Flores, PEE IIEE State of Qatar Chapter

What is a Gas Turbine Combined Cycle? A combined-cycle power plant uses both gas turbines and a steam turbine together to produce up to 50 percent more electricity from the same fuel than a traditional simple-cycle plant. The waste heat from the gas turbine exhaust routed directly to the heat recovery steam generator to produce steam and routed to the nearby steam turbine which generates extra power.

Combined Cycle Power Plant

GTCC Power System 1.) Fuel Tanks or Natural Gas Facility 2.) Black Start System 3.) Gas Turbine Units 4.) Heat Recovery Steam Generators 5.) Steam Turbine Unit 6.) Main and Auxiliary Transformers 7.) Local and Central Control Room 8.) Feed Water System 9.) Main Condenser 10.) Main Cooling Water System 11.) High Voltage Switchyard 12.) Other Balance of Plant (BOP)

Gas Turbine Combined Cycle Efficiency GAS TURBINE = 30 – 33%

COMBINED CYCLE = 20 – 25% TOTAL NET EFFICIENCY = 50 – 60%

World Record Highest Efficiency

The 600 MW Combined Cycle Power Plant Irsching 4 by Siemens achieved a world record highest efficiency of 60.75 (net) in May 2011 in Erlargen Germany

Bataan Combined Cycle Power Plant Philippines

The 600 MW Combined Cycle Power Plant in Limay Bataan Philippines was the first of its kind in the Philippines commissioned in 1992 as a fast track project during the nation wide black-outs in our country due to lack of power plants to support the booming economy.

Efficiency of Power Plants

Gas Turbine = 26% - 33% Diesel Generator = 39% - 45% Combined Cycle (Dual Pressure) = 38% - 47%

E-Development

FUEL SUPPLY SYSTEM

Standard Fuel for GT 1.) Jet A/Kerosene 2.) Natural Gas 3.) Distillate (including No.2 Fuel oil and Diesel oil)

Natural Gas Supply

Standard Natural Gas Storage Tank

Natural Gas Supply

Gas Pressure Reducing Station: It reduces the natural gas pressure supplied by the Oil Refineries to the gas pressure required by the Gas Turbine Units . For example: From 70 Bars to 30 Bars.

Natural Gas Supply

Japan is the highest importer of LNG.

Natural Gas Supply

Global gas imports is increasing fast.

Diesel Fuel Tank Facility

Consist of the following components: 1.) Diesel Fuel Tank Farm 2.) Fuel Treatment Facility 3.) Fuel Forwarding Pumps 4.) Fuel Pipe Lines

Fuel Treatment Plant

Electrostatic Separator is a descriptive term of Baker, which means the treatment of crude oil through mixture of water and high voltage current. So far the measurement has been widely used and agreed in oil refining industry and turbine power stations worldwide. Because fractions of metallic contaminations, especially Na, K, V and Pb, exist in fuel oil, they frequently suffer to high temperature erosion and fouling. In the process of combustion, these impurities will form mixed dust subject in low melting point, which can cohere with the metallic parts in the hot gas path. With the accumulation of these melted dust subjects on thermalloy material, high temperature erosion will happen and as a result, will lead parts to failure.

Diesel Fuel Tank

Fuel Tank Protections 1.) Lightning arresters 2.) Flame Detectors 3.) Foam spray inside the tank 4.) Deluge Cooling water spray outside and around the tank 5.) Grounding System 6.) Tank overflow 7.) Containment Wall 8.) Fire Fighting Equipment

Deluge Fire Protection Skid

Deluge Fire Pumps

Tank Farm On Fire

Common cause of Fuel Tanks fire: 1.) Lightning strikes 2.) Human or operators error 3.) Fuel pipe line leaks

BLACK START SYSTEM

What is a Black Start System? It is the process of starting or restoring an electric power station to operation without relying on the external transmission network. This normally happens during total loss of power in the grid on a bad weather. In order to have a black start capability, most power plants have a dedicated diesel generator of 2MW to 5MW capacity called the Black Start Diesel Generator (BSDG), which can be used to restart back the first gas turbine generator and its auxiliaries back in service which will in turn provide enough supply of power to start the other remaining gas turbines to restore back the whole Power Plant during black out condition.

Black Start Diesel Generator

Consist of the following components: 1.) Diesel Engine 2.) Generator (2MW – 5 MW) 3.) Air Starting System (Small Diesel Engine Driven) 4.) Synchronizing and Monitoring Equipment

GAS TURBINE

What is a Gas Turbine? A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled to a downstream turbine, and a combustion chamber in between. The gas turbine is the heart of the power plant. A gas turbine is a combustion engine that can convert natural gas or other liquid fuels to mechanical energy which then drives a generator that produces electrical energy or power output.

Gas Turbine Unit

Consist of the following components: 1.) Air Intake System 5.) Starting Unit 2.) Compressor and Blow-off 6.) Shaft and Bearings 3.) Turbine 8.) Exhaust Stack 4.) Generator 9.) Local Control Room

Gas Turbine Main Parts

Gas Turbine Unit

Combustion Chamber and Turbine

Gas Turbine Range

ABB Gas Turbine MW Range

Gas turbine technology  Gas turbine power flow Exhaust gas

Power turbine Pt

Combustion chamber Pth

Compressor air

Pk

gearbox

generator

Pm

Liquid fuel

Pel

Pch Pt = Pk + Pm

Chemical power

Thermal power

Mechanical power

Electrical power

Global efficiency = Pel/Pch 33

Industrial Gas Turbine

Consist of the following main components: 1.) Inlet Air 2.) Compressor 3.) Combustion Chamber 4.) Turbine 5.) Exhaust

Gas Turbine compared to 4-stroke Engine

Admission

Compression

Combustion

Exhaust

Consist of the following steps: 1.) Admission – Admits mixture of air and fuel in to the cylinder. 2.) Compression – Compressed air using stages of blades. 3.) Combustion – Mixed compressed air and fuel then ignited to produce mechanical work. 4.) Exhaust – Hot gas is being released to the exhaust stack or to the steam boiler.

Gas Turbine

Gas Turbine Powered Car

Progress in blade metals

Gas Turbine Blade Damaged

Gas turbine rotor blades damaged by blade rubbing due to high vibrations. High vibrations can cause the rotor blades to rub against the turbine casing.

Gas Turbine Blade Metal Nickel base super alloys are used in the most demanding portions of the turbine engine, where a wide balance of high strength, high toughness, oxidation and corrosion resistance, temperature capability, and process ability are all needed. The blades used in the high pressure turbine rotor are subjected to a stringent set of requirements including a balance of creep resistance, temperature capability, environmental resistance, and damage tolerance. In today's engines, blade performance and durability is achieved through advanced super alloy single crystals combined with sophisticated internal cooling schemes and thermal barrier coatings.

Research is directed towards further advances in new alloys, where low density alloys with improved strength at temperatures exceeding 1100°C have been discovered.

Turbine Bearings

Axial Thrust Bearing Bearing No.1 Air Inlet Assembly

Radial Journal Bearing Bearing No.2 and 3 Combustor Assembly

Gas Turbine Starting Unit

Gas Turbine Starter is equipped with two starter motors used for turbine start-up and is used to drive the mechanical main oil pump. It has a gear box to reduce the drive speed of 14,950 rpm from the turbine to generator speed of 1500 rpm.

Gas Turbine Starting Unit The Gas Turbine Unit has the main function the following: 1.) To put the turbine in rotation to reach ignition speed (25 % of nominal speed). 2.) When combustion occurs, it supports the acceleration of the turbine.

3.) When turbine reached 66 % of nominal speed the starter motor is de-energised. The turbine will be at self sustaining speed to reach 100% or full speed.

Gas Turbine Starting Unit

Gas Turbine Static Frequency Converter (SFC) uses the synchronous generator of the gas turbine to operate it as a motor to run up to ignition speed and self sustaining speed.

Gas Turbine Generator

Consist of the following components: 1.) Rotor Winding 5.) Output Terminals 2.) Stationary Winding 6.) Bearings 3.) Exciter 7.) Shaft 4.) Diodes

GT Local Control Room

Control, Monitoring and Protections

Central Control Room

Control, Monitoring and Protections

Central Control Room

Typical Central Control Room Operator

Gas Turbine Protections 1.) Pedestal bearing vibrations >Max. 2.) Thrust bearing vibrations >Max. 3.) Turbine casing vibration >Max. 4.) Electronic over speed >110% 5.) Mechanical over speed >112% 6.) Turbine Inlet Temperature (TIT) 7.) Temperature After Turbine (TAT) 8.) Lube pressure and level Max. 3.) HP/LP Drum Level >Max. 4.) HP/LP Drum Level