How do you maintain a steam turbine?
Steam turbine bearings and seals should be physically inspected every two to three years. This entails opening the bearing housings; removing and inspecting the bearings and seals; and replacing any components as needed. The work is generally done during a planned shutdown.
How long does a steam turbine last?
Maintenance requirements of modern steam turbines are simple and incur low costs (typically around $0.005 per kWh); their operational life often exceeds 50 years.
What material is used for steam turbine blades?
Blades under high and medium pressure are usually made of stainless steel from 12Cr, but are made of stainless steel at temperatures above 450 degrees, because stainless steel has better properties at high temperatures.
What is the best material for turbine blades?
FIBERS
| Fiber | Diameter, µm | CTE, 10-6/°C |
|---|---|---|
| High strain | 1.8 | 1.6-2.0 |
| Intermediate modulus | 1.8 | 1.8 |
| Carbon, pitch based | ||
| P25 | 10 | -0.9 |
What is turbine maintenance?
Turbine repair and maintenance services provide maintenance, overhauls, and repairs to wind, gas, steam, and water turbines. Turbine repair and maintenance services may include troubleshooting, testing, inspection, disassembly and reassembly, maintenance, field or shop repair, and complete machine overhauls.
What is considered good steam quality?
A steam quality of 0 indicates 100 % liquid, (condensate) while a steam quality of 100 indicates 100 % steam. Saturated steam (meaning steam that is saturated with energy) is completely gaseous and contains no liquid. The boiler operation uses chemical energy from a fuel source to deliver energy to the boiler water.
What is the reheating of steam in a turbine?
In a reheat cycle, the expansion takes place in two turbines. The steam expands in the high-pressure turbine to some intermediate pressure, then passes back to the boiler, where it is reheated at constant pressure to a temperature that is usually equal to the original superheat temperature.
Why do steam turbine blades get bigger?
Often the impulse stages come first and extract energy from the steam when it’s at high pressure; the reaction stages come later and remove extra energy from the steam when it’s expanded to a bigger volume and lower pressure using longer, bigger blades.
What limits the life of jet engine turbine blades?
High temperature corrosion and oxidation of the gas turbine material is a significant life limiting factor. The combustion gases, particularly from heavy fuels, contain several aggressive corrosion elements such as sodium, potassium, lead and vanadium which cause corrosion of the hot gas path components.
What are the three types of turbine blades?
Turbine blades are classified into three types: Impulse, reaction, and impulse-reaction. ducts as turbine blades.
What is swing check of turbine?
Swing check is a measurement which shows the mating accuracy of the coupling faces of the two rotors coupled together. Readings are taken at many positions, The max throw is the Swing of the rotor. Readings are to be recorded after elongation of all coupling bolts of HP-IP and IP-LP coupling.
What is poor steam quality?
Steam quality is very important but many times unrecognized as a detriment in a steam system. Wet, dry, clean, and pure steam concepts are defined. Poor steam quality can result in four consequences: product contamination, poor heat transfer, damage system equipment, and overtaxation of boiler feed equipment.
What are the different types of steam turbine repair?
Three major steam turbine repair types have become clear as a result of this shift in maintenance focus. Failure Based – Component failure with collateral component damage, forced outage & repair Failure Avoidance Based – Repair need identified & repair planned at next opportunity
What are failure avoidance based steam turbine repairs?
Failure Avoidance Based repairs are a step in the right direction, this type of repair is classified as those that have been identified via inspection practices and planned for at the next outage. Planned Reliability Centered Maintenance repairs have simply not had the focus required to ensure long term reliability of the steam turbine.
Why are steam turbine blades manufactured in days?
This transition has reduced cycle by eliminating costly set up time, product scrap and rework costs narrowing in on one blade at a time. It has now become common (if the appropriate bar stock is on site) for steam turbine blade rows to be manufactured in days vs weeks.
Is there a maintenance interval for steam turbines?
With regards to maintenance practices in North America and Europe, there are no regulatory maintenance practices or intervals specified for non-nuclear steam turbines regardless of the industry or application.