Search this site
Embedded Files
SMART_HSE
  • Home
  • HSE BULLETINS
  • HSE NEWS
  • OIL&GAS OPERATIONS
    • Production Operations
      • MULTISTAGE CENTRIFUGAL COMPRESSORS
      • Cavitation Process
      • P&IDs
      • Steam Turbine
      • Boiler
      • Pumps
      • Heat Exchanger
      • Flare System
      • HVAC System
      • PLC Programming Tutorial
      • SCADA System
      • Types of Valve used in Piping
      • Breathing Valve
      • Subsea Welding
      • Deaerator
      • Ductwork sizing
      • Time-of-Flight measuring principle
      • Vortex Flow Meter
      • The Electromagnetic Flow Measuring Principle
      • The Differential Pressure Flow Measuring Principle (Orifice-Nozzle-Venturi)
      • Differential pressure level transmitter - Endress + Hauser Continuous le
      • Ultrasonic Level Transmitter
      • The Coriolis Flow Measuring Principle
      • Turbidity measurement
      • Dissolved oxygen measurement
      • Potentiometric pH measurement
      • Gas Turbines - Combined Cycle
      • Steam Trap
      • Pneumatic Cylinder
    • Well Operations
      • Well Operations Safety Videos
      • IWCF Training Course
      • Deep Water Drilling
    • Reservoir Management
      • Reservoir Engineering
      • Natural Gas
  • SAFETY VIDEO (Safety Moments)
    • 1. Near Miss, Unsafe Act, Unsafe Conditions
    • 2. Line Of Fire
    • 3. Work at Height
    • 4. Confined Space
    • 5. Lifting Operations
    • 6. Electrical Safety
    • 7. Permit To Work System PTW
    • 8. Fire Safety
    • 9. Excavation Safety
    • 10. Road Traffic Safety
    • 11. Toxic Gas
    • 12. Process Safety
    • 13. Welding Operations
    • 14. Videos of Accidents
    • 15. Ramadan
    • 16. Other Safety Videos
    • -> YouTube HSE Channels
  • ENVIRONMENTAL VIDEO (Moments)
    • 1. Water Management
    • 2. Waste Management
    • 3. Gas Flaring
  • HSE MANAGEMENT SYSTEM
    • ISO 9001
    • ISO 14001
    • ISO 39001
    • ISO 45001 (OHSAS 18001)
    • 1. Risk Management
    • 2. HSE Management in Oil & Gas Industry
    • 3. Health Management
    • 4. Contractor Management
  • EAST WIND
    • Life Saving Rules Program
    • Contract Management
    • Environmental Management
    • Safety Competence Assessment
    • My Personal Commitment
    • Dropped Object Prevention
    • Process Safety
    • Defensive Driving Training
    • Well Operation Inspection Program
    • KPI for Well Ops
    • Five Stars Campaign
    • Booklets for CoW and LSR
    • Hand Working Safety Campaign
    • Inside Lesson Learnt
    • The 7 Hazardous Energies
    • No Crushing, Line of Fire
    • Hazard Identification Program
    • Reporting
    • HSE Walkthrough Site Visit Report
    • HSE IMS Alignment
    • SIMOPS
    • Digitalization
    • Safety Communication
    • Awareness 3.0
  • SMART_HSE DRIVE
    • 00. COVID_19
    • 0. IOGP STATISTICS & REPORT
    • 1. TRAINING & AWARENESS
    • 2. HSE ALERT
    • 3. SAFETY MOMENTS
    • 4. LESSON LEARNT
    • 5. LIFTING OPERATIONS
    • 6. DROPPED OBJECT
    • 7. BOOKLETS
  • HSE WEBINAR & MAIN EVENTS
  • SAFETY VIDEO INDUCTION
  • LESSON LEARNT
  • HSE ALERT & OTHERS WEBSITE
  • WEATHER FORECAST
  • Oil & Gas Companies
SMART_HSE

Steam Turbine

steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Its modern manifestation was invented by Charles Parsons in 1884.[1][2]

The steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple stages in the expansion of the steam, which results in a closer approach to the ideal reversible expansion process. Because the turbine generates rotary motion, it is particularly suited to be used to drive an electrical generator—about 85% of all electricity generation in the United States in the year 2014 was by use of steam turbines.[3]

Types

Steam turbines are made in a variety of sizes ranging from small <0.75 kW (<1 hp) units (rare) used as mechanical drives for pumps, compressors and other shaft driven equipment, to 1,500 MW (2,000,000 hp) turbines used to generate electricity. There are several classifications for modern steam turbines.

Blade and stage design

Turbine blades are of two basic types, blades and nozzles. Blades move entirely due to the impact of steam on them and their profiles do not converge. This results in a steam velocity drop and essentially no pressure drop as steam moves through the blades. A turbine composed of blades alternating with fixed nozzles is called an impulse turbine, Curtis turbine, Rateau turbine, or Brown-Curtis turbine. Nozzles appear similar to blades, but their profiles converge near the exit. This results in a steam pressure drop and velocity increase as steam moves through the nozzles. Nozzles move due to both the impact of steam on them and the reaction due to the high-velocity steam at the exit. A turbine composed of moving nozzles alternating with fixed nozzles is called a reaction turbine or Parsons turbine.

Except for low-power applications, turbine blades are arranged in multiple stages in series, called compounding, which greatly improves efficiency at low speeds.[18] A reaction stage is a row of fixed nozzles followed by a row of moving nozzles. Multiple reaction stages divide the pressure drop between the steam inlet and exhaust into numerous small drops, resulting in a pressure-compounded turbine. Impulse stages may be either pressure-compounded, velocity-compounded, or pressure-velocity compounded. A pressure-compounded impulse stage is a row of fixed nozzles followed by a row of moving blades, with multiple stages for compounding. This is also known as a Rateau turbine, after its inventor. A velocity-compounded impulse stage (invented by Curtis and also called a "Curtis wheel") is a row of fixed nozzles followed by two or more rows of moving blades alternating with rows of fixed blades. This divides the velocity drop across the stage into several smaller drops.[19] A series of velocity-compounded impulse stages is called a pressure-velocity compounded turbine.

By 1905, when steam turbines were coming into use on fast ships (such as HMS Dreadnought) and in land-based power applications, it had been determined that it was desirable to use one or more Curtis wheels at the beginning of a multi-stage turbine (where the steam pressure is highest), followed by reaction stages. This was more efficient with high-pressure steam due to reduced leakage between the turbine rotor and the casing.[20] This is illustrated in the drawing of the German 1905 AEG marine steam turbine. The steam from the boilers enters from the right at high pressure through a throttle, controlled manually by an operator (in this case a sailor known as the throttleman). It passes through five Curtis wheels and numerous reaction stages (the small blades at the edges of the two large rotors in the middle) before exiting at low pressure, almost certainly to a condenser. The condenser provides a vacuum that maximizes the energy extracted from the steam, and condenses the steam into feedwater to be returned to the boilers. On the left are several additional reaction stages (on two large rotors) that rotate the turbine in reverse for astern operation, with steam admitted by a separate throttle. Since ships are rarely operated in reverse, efficiency is not a priority in astern turbines, so only a few stages are used to save cost.

https://en.wikipedia.org/wiki/Steam_turbine

Google Sites
Report abuse
Page details
Page updated
Google Sites
Report abuse