Book cover

Encyclopedia of Tribology pp 3292–3299 Cite as

Steam Turbine Oils

  • James B. Hannon P.E., C.L.S 3  
  • Reference work entry

188 Accesses

R & O oil ; Steam turbine lubricants ; Turbine oil

Steam turbine lube oil enables the rotation of large turbine rotors, supported by journal bearings and centered by thrust bearings, in the generation of electricity. Steam turbine oil facilitates reliable rotation of the large turbine rotors by providing two major functions, lubrication and heat removal. The turbine oil must provide suitable lubrication as the turbine rotor speed increases from stationary to low speed where boundary lubrication is the primary lubrication mode, and finally to full speed, where hydrodynamic lubrication is in effect. Maintaining clean, cool, and dry steam turbine oil supports long and reliable turbine operation and turbine oil life.

Scientific Fundamentals

Proper lubrication of steam turbines is critical to avoid costly equipment downtime and repair. The key elements of steam turbine lubrication are:

Turbine oil selection

Turbine oil system components and operation

Turbine oil maintenance

This is a preview of subscription content, log in via an institution .

Buying options

  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
  • Available as EPUB and PDF
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

ASTM International, ASTM Standards D 1401, D 892, D 445, D 664, D 2272, D 4378, D 4304, D 4927, D 5182, D 5185, D 6304, D 665, D 6439, D 6443, D 7155 and D 6971 , West Conshohocken

Google Scholar  

C. Baurer, M. Day, Pall Corporation, Water Contamination in Hydraulic and Lube Systems. Practicing Oil Analysis Magazine, Sept 2007

H.P. Bloch, Practical Lubrication for Industrial Facilities (Fairmont, Lithburn, 2000)

Book   Google Scholar  

A. Osborne, Modern Marine Engineer’s Manual , 2nd edn. (Cornell Maritime, Centerville, 1980)

D.M. Pirro, A.A. Wessol, Lubrication Fundamentals ExxonMobil Lubricants & Specialties , 2nd edn. (Marcel Dekker, New York, 2001)

Download references

Author information

Authors and affiliations.

Division of Exxon Mobil Corporation, ExxonMobil Lubricants & Petroleum Specialties Company, 1 Alexander Drive, 08501, Allentown, NJ, USA

James B. Hannon P.E., C.L.S

You can also search for this author in PubMed   Google Scholar

Corresponding author

Correspondence to James B. Hannon P.E., C.L.S .

Editor information

Editors and affiliations.

Department of Mechanical Engineering and Center for Surface Engineering and Tribology, Northwestern University, Evanston, IL, USA

Q. Jane Wang

Department of Materials Science and Engineering and Center for Surface Engineering and Tribology, Northwestern University, Evanston, IL, USA

Yip-Wah Chung

Rights and permissions

Reprints and permissions

Copyright information

© 2013 Springer Science+Business Media New York

About this entry

Cite this entry.

Hannon, J.B. (2013). Steam Turbine Oils. In: Wang, Q.J., Chung, YW. (eds) Encyclopedia of Tribology. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-92897-5_954

Download citation

DOI : https://doi.org/10.1007/978-0-387-92897-5_954

Publisher Name : Springer, Boston, MA

Print ISBN : 978-0-387-92896-8

Online ISBN : 978-0-387-92897-5

eBook Packages : Engineering Reference Module Computer Science and Engineering

Share this entry

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

  • Publish with us

Policies and ethics

  • Find a journal
  • Track your research

AIChE The Global Home of Chemical Engineers

  • Contact AIChE
  • Communities
  • Learning & Careers
  • Publications
  • Careers at AIChE
  • Equity, Diversity, Inclusion
  • Young Professionals
  • Operating councils
  • Local Sections

Other Sites & Tools

Technical groups, follow aiche, you are here.

  • August 2018

Essentials of Steam Turbine Design and Analysis

Effective design, analysis, and integration of steam turbines can help optimize steam supply reliability and overall energy efficiency across your plant.

Steam turbines are important components of process plant utility systems. They offer opportunities for optimizing steam supply reliability, as well as site-wide energy efficiency. Steam turbines are most common in the oil refining, ammonia and urea, methanol, ethylene, and pulp and paper industries, where they are generally sized to produce 10–60 MW of power. Good economics are also possible at smaller sizes as low as 2 MW, which are more common in the food and beverage industries, as well as in small to medium-sized plants in the chemical process industries (CPI).

Achieving favorable steam turbine economics depends on choosing the right type of turbine ( e.g., backpressure vs. condensing) in the right size, as well as integrating it correctly with the heat exchanger network (HEN) in accordance with the appropriate placement principle of pinch analysis.

This article reviews the thermodynamic relationships and equations that link steam flow conditions and power output, which are useful for estimating preliminary economics of new turbines and analyzing the performance of existing units.

Any device that converts the chemical energy contained in a fuel into mechanical energy ( i.e., shaftwork) via combustion is called a heat engine. Heat engines are generally classified according to the thermodynamic cycle that they follow. The most common heat engines in industrial applications are steam turbines (Rankine cycle), gas turbines (Brayton cycle), and internal combustion engines (Otto cycle).

Although gas turbines can also play an important role in the economic optimization of the combined heat and power (CHP) utilities at manufacturing plants, this article focuses exclusively on steam turbines. Steam turbines have four typical operating modes:

images

▲ Figure 1. Steam turbines come in many different configurations, including (a) backpressure turbines (BPSTs) operated in cogeneration mode and (b) condensing turbines (CSTs) for power generation. Hybrid configurations, such as (c) extraction turbines and (d) induction turbines, are less common.

Backpressure steam turbines (BPSTs) produce low-pressure (LP) exhaust steam that can be used for one or more process heating duties ( Figure 1a ). The objectives are to provide the process with steam of the quantity and pressure required by the process, while generating the maximum amount of power so as to reduce the need for purchased power. Because BPSTs cogenerate two energy products ( i.e., steam and power) simultaneously, they have an effective heat rate of 4,500–5,500 Btu/kWh, which represents an energy efficiency two to three times better than that of a condensing turbine, even after taking into account both boiler and turbine energy losses. (Heat rate is the amount of fuel that is converted by a heat engine into useful power — the lower the number, the better. The minimum possible heat rate is 3,413 Btu/kWh, representing 100% conversion of fuel energy into power.)

Pure BPSTs are used mostly in industrial facilities that operate continuously, where the goal is high thermodynamic efficiency and the energy demands are relatively stable. They are typically sized for 3–60 MW.

Condensing steam turbines (CSTs) exhaust steam to a condenser at atmospheric pressure or the lowest possible pressure at which it can be condensed with the available cooling utility ( Figure 1b ). In locations with a ready supply of water, cooling is usually accomplished via a closed loop that circulates through an evaporative cooling tower. In arid regions, such as the Middle East, North Africa, and the Southwestern U.S., air-cooled heat exchangers are usually more practical than wet cooling towers.

Utility power plants use CSTs exclusively because their objective is to maximize power generation and there is no use for exhaust heat from BPSTs in the Rankine power-generation cycle. Power plant CSTs are typically sized in excess of 100 MW and have heat rates of 11,000–16,000 Btu/kWh, depending on factors such as the pressure and temperature of the inlet steam, the temperature of the cooling medium, and the turbine isentropic efficiency.

Extraction-condensing turbines (ECTs) are hybrids, in which some of the exhaust steam is extracted at pressures high enough for process heating (cogeneration mode) and the rest is condensed by a cooling utility for power generation (noncogeneration mode) ( Figure 1c ). ECTs are less common in industry, because they are more expensive to buy and maintain and are more difficult to control.

Induction turbines are hybrids that offer very high system efficiencies, because they extract power from steam that would otherwise have to be let down in pressure through a throttling valve ( Figure 1d ). They typically receive two sources of inlet steam at different pressures ( e.g., high pressure and medium pressure) and exhaust at a single lower pressure ( e.g., ambient pressure or vacuum).

Figure 1d illustrates a simple case in which an induction turbine would be appropriate. The process is exothermic and generates more LP steam than is needed for process heating duties, but it needs high-pressure (HP) steam for other higher-temperature duties. With only two steam pressure levels, the required amount of HP steam is sent straight to the processes that need it, while the surplus exhaust from the turbine is condensed by a cooling utility for additional power generation (noncogeneration mode). Induction turbines are even less common than extraction turbines, because they are more expensive to buy and maintain and more difficult to control.

Design and rating calculations

The expansion process that occurs in a properly insulated steam turbine is essentially an adiabatic process. The enthalpy difference between the inlet and exhaust steam (neglecting frictional losses) is almost fully converted into mechanical energy, which can then be used to drive a pump, a compressor, or an electric generator.

images

▲ Figure 2. The adiabatic expansion of steam in a turbine is most conveniently represented on the enthalpy-entropy (H-S) Mollier diagram. Point 1 = turbine inlet, Point 2 = low-pressure exhaust for process heating (cogeneration mode), Point 3 = exhaust to utility condenser (power-generation mode).

This process can be followed on an enthalpy-entropy (H-S) diagram, known as a Mollier chart. In the example diagram ( Figure 2 ), the path from Point 1 to Point 2 represents typical BPST operation at a chemical plant, pulp and paper mill, oil refinery, or food processing facility; superheated 600-psig steam at 700°F (Point 1) expands as it passes through the turbine and is exhausted at a pressure of 50 psig (Point 2). The path from Point 1 to Point 3 represents CST operation with the goal of maximum power generation to minimize the need for imported power under normal operation or to compensate for temporary loss of imported power from the grid. HP steam is exhausted at vacuum conditions and is condensed against a cooling utility.

Steam turbines typically rotate at 3,000–15,000 rpm. At that speed, water droplets can form and unbalance the turbine blades, causing severe mechanical damage. BPSTs can usually operate safely at up to 3% moisture ( i.e., a minimum steam quality of 97%). CSTs specially designed for utility-scale power plants can handle as much as 10–12% moisture. Process plants should avoid normal operation at this limiting condition, and should aim to stay at least 20°F above the exhaust steam dewpoint.

These operational constraints are needed to effectively analyze turbine power output, whether for design or rating calculations. To determine the adiabatic power output of the example BPST (Point 1 to 2, Figure 2 ), we first determine the total enthalpy change for isentropic expansion down to the exhaust pressure of 50 psig (Point 1 to Point 2*). Then we apply the isentropic efficiency (η T ), which is a combined indicator of the original machine design and its present mechanical condition:

images

where H 1 is the enthalpy of the HP inlet steam (Btu/lb), H 2 is the actual enthalpy of exhaust LP steam (Btu/lb), and H 2 * is the enthalpy of the exhaust LP steam assuming isentropic expansion (Btu/lb).

The adiabatic power output can then be calculated by:

images

where W is the work output (kW), M is the mass flowrate of steam (lb/hr), and 3,412 is the approximate conversion factor to convert Btu to kWh.

The isentropic efficiency cannot be determined exactly, but it can be estimated fairly accurately using empirical correlations based on historical industry experience, which are usually available from steam turbine vendors. When purchasing a steam turbine, it is good practice to require all bidders to provide values of η T for each machine over the range of expected load conditions. Monitoring an existing turbine’s efficiency loss can provide advance warning of impending turbine problems.

Reference 1 provides some data on real turbine operation, but the dataset is too small to draw general conclusions. The most reliable and useful correlations for new turbines can be found in Ref. 2. The η T for a steam turbine can be determined iteratively using:

images

where a and b are functions of W ( Table 1 ). Determining the values of a and b from Table 1 requires iteratively calculating the difference between the saturation temperature at the inlet ( T sat,i ) and outlet ( T sat,o ) in degrees Celsius (Δ T ).

Would you like to access the complete CEP Article?

No problem. You just have to complete the following steps.

You have completed 0 of 2 steps.

You must be logged in to view this content. Log in now.

AIChE Membership

You must be an AIChE member to view this article. Join now.

Copyright Permissions 

Would you like to reuse content from CEP Magazine? It’s easy to request permission to reuse content. Simply click here to connect instantly to licensing services, where you can choose from a list of options regarding how you would like to reuse the desired content and complete the transaction.

A Shortcut to Determine Optimal Steam Pipe Diameter

Use scare tactics to communicate major incidents, turnarounds: strategic opportunities to improve, departments, books: august 2018, catalyzing commercialization: high-performance adsorbent captures natural gas and reduces emissions, editorial: citizen science in the great outdoors, institute news: august 2018, aiche journal highlight: new directions in chemical engineering research appear in the inaugural futures issue, meeting preview: visions for chemical engineering’s future highlight aiche annual meeting, oct.28–nov. 2, pittsburgh, new products: august 2018, cep: news update, process safety beacon: what if your agitator fails, spotlight on safety: the three-legged stool of psm, technical entity trends: engineer your gut, career corner: build an effective collaborative team.

piping engineers blog

Steam Turbines: Basics, Types, Selection, Components, Construction, Codes, Manufacturers

A Steam Turbine is an engine that converts heat energy from pressurized steam into mechanical energy where the steam is expanded in the turbine in multiple stages to generate the required work. Steam turbine engines are used to produce electricity and drive countless machines worldwide (used as the prime mover for pumps, compressors, and other shaft-driven equipment). The capacity of steam turbines can vary from a few kilowatts to several hundred megawatts. Sir Charles A. Parsons developed the first modern steam turbine in 1884.

The Power in a steam turbine is generated by the rate of change of momentum of a high-velocity jet of steam impinging on a curved blade that is free to rotate. Fig. 1 below shows a schematic representation of a steam turbine with its associated auxiliaries.

Schematic of Steam Turbine Power Generation

Working Principle of Steam Turbines

The heat energy of steam is converted into mechanical work while expanding in the turbine. Steam is generated inside a boiler. The expansion of steam takes place through a series of fixed blades (nozzles) and moving blades. The working of a steam turbine is based on the thermodynamic cycle called the “Rankine cycle”.

Rankine Cycle:

The Rankine cycle is an idealized thermodynamic cycle of a heat engine that converts heat into mechanical work while undergoing a phase change. The concept is developed by William John Macquorn Rankine, a Scottish polymath and Glasgow University professor. It is an idealized cycle in which friction losses in each of the four components are neglected. The heat from an external source is supplied to a closed-loop, which normally uses water as the working fluid. Refer to Fig. 2

Rankine Cycle

Fig. 2 above represents the Rankine Cycle and the Temperature and Entropy are plotted in the curve. The processes can be described as follows:

  • Process 1–2 Isentropic compression – Adiabatic Pumping: The working fluid is pumped from low to high pressure. The fluid, being liquid at this stage, the pump requires little input energy.
  • Process 2–3 Constant pressure heat addition in a boiler – Isobaric Heat Supply: The high-pressure liquid enters a boiler, where it is heated at constant pressure by an external heat source to become a dry saturated vapor (steam). The required energy input can easily be calculated graphically, using an enthalpy–entropy chart (Mollier diagram or h-s chart), or numerically, using steam tables.
  • Process 3–4 Isentropic expansion – Adiabatic Expansion: The dry saturated vapor expands through a turbine, generating power. The temperature and pressure of the vapor are reduced causing some condensation.
  • Process 4–1 Constant pressure heat rejection in condenser – Isobaric Heat Rejection: The wet vapor then enters a condenser, where it is condensed at a constant pressure to become a saturated liquid.

Types of Steam Turbines

Steam Turbine Types can be classified based on various parameters as listed below:

  • Impulse Turbine and
  • Reaction Turbine
  • Single-stage Turbine and
  • Multistage Turbine
  • Rateau type(Pressure compounded stages)
  • Curtis type (Velocity compounded stage)
  • Reaction stage type
  • Axial flow turbine and
  • Radial flow turbine
  • Single-Shaft
  • Multi-shaft.
  • Transverse type
  • Vertical type
  • Bypass governing.
  • one or more intermediate-stage extraction
  • back pressure
  • Low-Pressure Steam Turbine
  • Medium Pressure Steam Turbine
  • High-Pressure Steam Turbine
  • Very High-Pressure Steam Turbine
  • Supercritical Pressure Steam turbine
  • Condensing Turbine
  • Backpressure Turbine
  • Extraction Turbine
  • Single-flow exhaust type
  • Multi-flow Exhaust type
  • Down exhaust
  • Top exhaust
  • Axial exhaust
  • Fixed speed
  • Low Speed (≤ 3000 rpm)
  • High Speed(≥ 3000 rpm)
  • Single valve type
  • Multi-valve type
  • Direct-drive type
  • Reduction type

The most basic steam turbine types are Impulse Turbine and Reaction turbine.

Impulse Steam Turbine

The basic idea of an impulse steam turbine is that a jet of steam from a fixed nozzle pushes against the rotor blades and impels them forward. So the impulse force of high-velocity steam exerts a force on the blade to turn the rotor. The kinetic energy of the steam is transferred to the rotating wheel by momentum transfer within the blades. Pelton Wheel, Banki Turbine, etc are typical examples of Impulse turbines.

Reaction Steam Turbine

In the reaction steam turbine, a jet of steam flows from a nozzle on the rotor (the moving blades) by fixed blades designed to expand the steam. The rotor gets its rotational force from the steam as it leaves the blades. Roughly 50% of the output power is generated by the impact force and the other 50% from the reaction force by the steam expansion. Francis Turbine, Kaplan Propeller turbine, Deriaz turbine, etc are examples of reaction turbines.

The main difference between impulse and reaction turbines lies in the way in which steam is expanded while it moves through them such that:

  • In the impulse-type steam turbine, the steam expands in the nozzle and its pressure doesn’t change as it moves over the blades.
  • In the reaction type, the steam expands continuously as it passes over the blades and thus there is a gradual fall in pressure during expansion.

Impulse Turbine vs Reaction Turbine

The major differences between an impulse turbine and a reaction turbine are tabulated below:

Difference Between Impulse and Reaction Turbine

Selection of Steam Turbines

The following table from JIS B0127 provides typical guidelines for the general features and selection criteria based on the type of steam turbines. Depending on the purpose, use, required output, location, arrangement, and circumstances appropriate type of steam turbine should be selected:

Components of a Steam Turbine

The major components that constitute a steam turbine are:

  • Casing: The Casing should withstand all normal and emergency service loads and allowable piping forces and moments caused by temperature change. The design of turbine casing design shall be such that thermal stresses are minimized. Adequate support must be provided to the steam turbine casing to maintain good alignment with the rotor.
  • Rotor: This is the main component in a steam turbine that carries the blades to convert thermal energy.
  • Blades: Blades absorb the energy of high steam velocity and convey it to the rotor. The shape of the blades significantly affects the turbine performance of turbine and requires high reliability.
  • Governor for speed control.
  • Servo Mechanism.
  • Oil Pump for lubrication.

Fig. 5 shows these components.

Steam turbine Components

Construction of a Steam Turbine

Often, Turbines are described by the number of stages that are grouped into different sections of the turbine. Depending on the pressure levels, the sections are known as the high pressure (HP) section, intermediate pressure (IP) section, or low pressure (LP) section. These turbine sections can be constructed in different types as mentioned below:

  • can be packaged into separate sections in a single turbine casing,
  • can be arranged into separate casings for each section, or
  • can be constructed in combination (HP/IP turbines in one casing and LP turbines in another).

Also, two turbines may be connected together in the same casing but in opposing directions to balance the thrust loads. Flow to these turbines is through the center of the casing and exits from each end of the turbine. These are referred to as turbines with double flows (i.e., opposing flow paths on the same shaft). However, the steam turbine MW rating is not indicative of section or casing numbers. Normally, less number of stages and casing will result in larger size blading and high loading for the same steam condition. The following Fig. shows a typical plot of the number of turbine casings as a function of steam turbine size

Number of Turbine Casing vs Steam Turbine Size

Losses in a Steam Turbine

  • Residual velocity loss.
  • Losses in regulating valves.
  • Loss due to steam friction in the nozzle.
  • Loss due to leakage.
  • Loss due to mechanical friction.
  • Loss due to wetness of steam.
  • Radiation loss.

Popular Problems of a Steam Turbine

  • Fatigue, Thermal / Corrosion (Pitting / Stress Corrosion Cracking – Steam quality & excessive process conditions).
  • Vibration (loose parts / excessive process conditions – Overload).
  • Misalignment (Vibration / poor maintenance workmanship).

Steam Turbine Protection Means

  • Over speed trip.
  • Master Trip.
  • Low Lubricating Oil Pressure Trip.
  • High Bearing Temp. Trip.
  • High Vibration Trip.
  • High Axial Displacement Trip.
  • Relief Valve in Exhaust

Techniques to Improve Steam Turbine Efficiency

Various techniques are employed to maximize steam turbine efficiency, each designed to attack a specific loss mechanism. For example:

  • the number of stages utilized can range from the fewest possible to develop the load reliably to the thermodynamically optimum selection.
  • Spill bands can be utilized to minimize throttling losses.
  • High-efficiency nozzle/bucket profiles are available to reduce friction losses.
  • To reduce the pressure within the exhaust casing, exhaust flow guides are available.
  • The specific features employed on a given application are usually based on the trade-off between capital investment and the cost to produce steam over the life of the turbine –SIMPLY, IT IS AN OPTIMIZATION APPROACH.

Process Surveillance – Why we should monitor closely?

Accurate measurement and tracking of parameters like temperature, pressure, and flow are important to plant safety and performance. Information collected at specific measuring points can be used to:

  • Avoid Metallurgical Failures: Temperatures need to be maintained below components’ melting points in order to avoid metallurgical failure. Too-high temperatures can also lead to creep deformation in the rotating blades.
  • Determine Efficiency and Performance: Calculate the efficiency of the turbine by knowing the inlet and exit temperatures, as well as the flow rate at the nozzle. When a turbine exhaust is used as heat input to a steam cycle, engineers can also estimate the performance of the heat recovery steam generator (HRSG) by using the temperature and flow measurement of the turbine exhaust.
  • Detect Inefficiencies : High exhaust temperatures and flow changes can be symptoms of an upset mode of turbine operation. If a flow measurement device picks up irregularities, the plant operator can perform a diagnostic to identify the underlying causes.
  • Calculate Residual Life: Tracking temperatures over time allows one To calculate how much life the component has left and to plan maintenance and replacements.

Process Surveillance – What & Where?

  • Barometric pressure.
  • The cold reheat.
  • The high-pressure throttle.
  • The hot reheat.
  • Low-pressure induction sections.
  • Exhaust pressure.

Steam Turbine Codes and Standards

Api 611 (iso 10436) 4th edition – general purpose steam turbines for refinery service (non-critical):.

  • General purpose turbines are horizontal or vertical turbines used to drive equipment that is usually spared, is relatively small in size (power), or is in non-critical service.
  • They are used where steam conditions will not exceed a pressure of 48 bar and a temperature of 400°C or where speed will not exceed 6000 rpm.

API 612 (ISO 10437) 6th Edition – Special purpose steam turbine for refinery service (critical):

  • The purchaser’s approval is required for built-up rotors when blade tip velocities exceed 250 m/s at maximum continuous speed or when stage inlet steam temperatures exceed 440 °C.
  • I. Electronic Overspeed detection system.
  • II. Electro-hydraulic solenoid valves.
  • III. Emergency trip valve(s) / combined trip and throttle valve(s).
  • If specified a turbine with an exhaust pressure less than atmospheric pressure shall be provided with an exhaust vacuum breaker actuated by the shutdown system.
  • Details of such a system shall be agreed upon by the purchaser and the turbine vendor.

Other codes and standards that are referred to for steam turbine applications are

  • ASME/NEMA SM23
  • IEC/TS 61370
  • BS EN60045-1
  • ASME PTC 6/6A
  • ASME/ANSI PTC 20.1/20.2
  • DIN EN 45510-5-1

Steam Turbine Manufacturer

Steam turbines are highly complex and sensitive pieces of machinery, and only a few manufacturers produce them worldwide. The majority of the steam turbines are manufactured by the following companies:

  • Harbin Electric
  • Shanghai Electric
  • Dongfang Electric
  • General Electric
  • Bharat Heavy Electricals Limited
  • Mitsubishi Heavy Industries
  • Elliot Group
  • and Toshiba.

Online Steam Turbine Courses

To update yourself regarding more details of steam turbines, the following online courses will help you. To enroll in any course, click on the subject, review the course and then enroll.

  • Fundamental Question on Steam Turbine Monitoring and Control
  • Steam boilers, engines, nozzles, and turbines Practice Questions

Related Posts:

What is a Vacuum Pump

Ahmed Shafik

Chemical Engineer with 18 years of Process and Operations’ hands-on experience in the hydrocarbon industry (Offshore / LNG / GTL / NGL / Utilities / Technology Provider / Engineering Consultancy) delivering leadership excellence and contribute to organizational success through handling different engineering occupations in process design, operations, project support, technical analyst, technical support and business development, Asset Engineering, and Process Engineering Technical Authority.

4 thoughts on “ Steam Turbines: Basics, Types, Selection, Components, Construction, Codes, Manufacturers ”

Dear sir Really this subject is informative for me.Please send this soft copy pdf to my mail.

Thanks Sazzad Hossain Turbine Shift Engineer HF Power Ltd. Bangladesh

Can you please elaborate on how turbine exhaust conditions can be used to assess the performance of HRSG? If possible please provide methodology as well.

Really need some more information about steam turbine about the risk of it and some advice about starting up a turbine while it’s loaded with machinery

very helpfull for me, thank a lot

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name and email in this browser for the next time I comment.

Recent Posts

Design of Sub-Sea Pipelines

Subsea pipelines play a critical role in transporting oil and gas (hydrocarbon) from remote exploration and production sites to processing facilities and ultimately, consumers. They are essential...

What are Pipeline Block Valves? Design of Pipeline Block Valve Stations

Pipeline block valves are one of the critical components in a pipeline network that ensures the proper management of liquids and gases that it transports. These valves play a crucial role in...

Turbomachinery Magazine

OR WAIT null SECS

  • Do Not Sell My Personal Information
  • Privacy Policy

MJHLS Brand Logo

© 2024 MJH Life Sciences ™ and Turbomachinery Magazine . All rights reserved.

Practical issues in steam turbines used in oil and gas applications

As discussed in earlier sections steam turbine auxiliaries need to be located relative to each other to ensure proper overall functioning. For instance, it is recommended that the oil system is located at a lower level relative to the steam turbine to ensure lube oil return to tank by gravity. If the oil system is at the same level with the steam turbine, then the return line shall respect a certain slope (4%). Run down tank shall be located at higher level than the steam turbine to ensure sufficient static oil pressure to the bearings during coast down.

This article contains excerpts from the paper, "Tutorial on large steam turbine systems in oil and gas applications," by Mounir Mossolly, Emmanuel Bustos and Guillaume Herve at the 2017 Turbomachinery Symposium.

Oil mist eliminator needs to be located at higher level than the lube oil console to ensure drainage of recovered oil back to the oil tank by gravity. Jacking oil pumps (skid) need to be located as close as possible to the shaft line to avoid safety issues of extended piping network of small bore piping at very high pressure that may have risks of rupture. On the other hand, the main condenser in oil & gas applications is located below the steam turbine for compactness purpose. And condensate pumps shall be located at a sufficient level below the condenser to maintain the necessary NPSH margin which is critical for the operation of the pumps.

It is recommended to install the gland steam condenser at a lower level relative to the steam turbine; though it is not absolutely mandatory. However, the condensate tank that collects the condensates from the steam gland condenser shall be located under the steam gland condenser to ensure condensate drainage flow by gravity.

Precautions for Offshore Applications

In offshore applications, the modular structures accommodating the steam turbine systems and other balance of plant equipment are very congested and space availability is very scarce. In such consideration, the most complex installation is for a condensing type steam turbine, which requires in addition to all the auxiliaries required for the back-pressure turbine full condensate and vacuum systems. Condensing type steam turbines are very usual for high power applications. However, for low power applications, it is recommended to have a backpressure steam turbine to avoid numerous auxiliaries that are required for the condensing type steam turbine. In addition to space constraints, site conditions such as wind load and sea motions need to be well adapted in the design. Sea motions are repetitive and returning; every 8 to 15 [seconds], inducing fatigue issues. Sea motions also cause deflections in decks causing relative displacements between fixed points. Accordingly, the design of the steam turbine and all its auxiliaries need to be comprehensive.

In contrast to onshore applications, sea motions need to be compensated in offshore applications by further increasing the slopes of interconnecting piping. One important example is the return oil line from the steam turbine to the lube oil tank, which needs to be properly sloped so that the oil can return from the steam turbine bearing house to the oil tank under the gravitational force at the maximum roll and pitch conditions. The slope shall be increased to cater for worst sea motion condition for which the package need to be in operation.

Noise Emissions and Mitigations

Large steam turbines are noisy machines with sound pressure levels exceeding long term exposure limits. Accordingly, noise attenuation technologies need to be applied and the area around the steam turbine need to be acoustically restricted without hearing protection. Noise emissions from large steam turbines can be attenuated by adding an acoustic enclosure, however this option adds execution complexity for the package. In addition, a noise enclosure will have an adverse effect on the availability of the steam turbine because of spurious or factual trips generated by high temperature and/or gas detection inside the enclosure.

Noise enclosure will also restrict mechanical handling flexibility, so the noise enclosure need to be designed in a way to be partially dismantled (and remain rigidly supported) during heavy mechanical handling such as rotor replacement. It shall be noted that ventilation fans that need to be installed for the enclosure of the steam turbine to dissipate heat by continuous air change-over are also noisy, and the overall noise levels need to be studies before deciding to have the noise enclosure. An alternative to the noise enclosure is to add noise barriers/ walls around the steam turbine (no roof), but this solution is less attractive in offshore projects which use modular design, because the upper deck will be affected by the noise from the steam turbine.

Another alternative is to have an acoustically restricted area around the steam turbine; operators/ technicians are not allowed to access this area without hearing/ ear protection. Acoustic blankets on the steam turbine are also another solution, however corrosion issues under the blankets need to be well investigated according to site conditions. Human factors and Safety Design Steam turbine systems are characterized by extended area of hot surfaces of various equipment which requires personnel protection.

Any surface which is above 60[°C] need to be isolated either by insulation or by a mechanical barrier such as a metallic mesh to avoid operators being in direct contact with the hot surface. Another important aspect in the design is to avoid threaded connections on high pressure and high temperature steam lines and pressure retaining parts by using flanged connections instead; which would provide better sealing. Threaded connection also need to be avoided for the oil (lube and control) piping which can easily lead to oil fires in case of leakage and contact with the hot turbine surface. In some applications the control oil used is different than the lube oil and can be even more inflammable.

Related Content:

Turbo Tips: How to Manage Bolt Connections & Bolt Joints in Turbomachines

Turbomachinery Magazine

  • Gas Turbines
  • Steam Turbines
  • Compressors
  • Auxiliaries
  • Company News
  • Energy & Conference News
  • Environment
  • All Magazine Posts
  • Myths & Tips
  • Handbook Home
  • Handbook Digital Advertising
  • 2021 Handbook Digital Download
  • White Papers
  • Free Webcasts
  • User Groups
  • Useful Links
  • TPS 2019 Videos
  • 2021 Media Planner
  • Terms & Conditions

trip oil pressure in steam turbine

Protection of steam turbines using reliable solenoid trip valves

trip oil pressure in steam turbine

One solenoid valve installed in the control oil system exposes the turbine to a spurious trip if the solenoid should open; and to catastrophic damage if the valve fails to open on command.

Installing two solenoid valves in parallel with another valve in series in each loop (total four solenoid valves) will result in the highest trip system reliability, since this will provide optimum assurance that one valve will open on command in addition to preventing an incidental solenoid valve opening.

In addition, having an online solenoid test for each valve every three months will provide optimum assurance that the solenoid trip system will function as necessary.

The function of the steam turbine protection system is often confused with the control system, but the two systems are entirely separate. The protection system only operates when any of the control system set point parameters are exceeded and the steam turbine will be damaged if it continues to operate.

The protection system monitors steam turbine total train parameters and ensures safety and reliability by the following action:

  • Start-up (optional) provides a safe, reliable fully automatic start-up and will shut down the turbine on any abnormality
  • Manual shutdown
  • Trip valve exerciser allows trip valve stem movement to be confirmed during operation without shutdown
  • Rotor over speed monitors turbine rotor speed and will shut down turbine when maximum allowable speed (trip speed) is attained
  • Excessive process variable signal monitors all train process variables and will shut down turbine when maximum value is exceeded

A multi-valve, multi-stage turbine protection system incorporates a mechanical over speed device (trip pin) to shut down the turbine on over speed (10 percent above maximum continuous speed). Centrifugal force resulting from high shaft speed will force the trip lever which will allow the spring loaded handle to move inward. When this occurs, the port in the handle stem will allow the control oil pressure to drain and drop to zero.

The high energy spring in the trip and throttle valve, normally opposed by the control oil pressure will close suddenly (less than 1 second). In this system there are two other means of tripping the turbine (reducing control oil pressure to 0 psi):

  • Manually pushing spring loaded handle
  • Solenoid valve opening

The solenoid valve will open on command when any trip parameter set point is exceeded. Solenoid valves are designed to be normally energized to close.

In recent years, the industry has required a parallel and series arrangements of solenoid valves to ensure increased steam turbine train reliability.

Most speed trip systems now incorporate magnetic speed input signals and two-out-of-three voting for increased reliability. The devices that trip the turbine internally are:

  • Loss of control oil pressure

Spring force automatically overcomes oil force holding valve open (approximate set point 50-65 percent of normal control oil pressure)

  • Manual trip (panic button)

Manually dumps control oil on command

Turbine excessive axial movement

That is, they directly reduce the control oil pressure causing a trip valve closure without the need of a solenoid valve (external trip method).

Two popular types of steam turbine shutoff valves use a high spring force, opposed by control oil pressure during normal operation, to close the valve rapidly on loss of control oil pressure.

It is very important to note that the trip valve will only close if the spring has sufficient force to overcome valve stem function. Steam system solid build-up, which increases with system pressure (when steam systems are not properly maintained), can prevent the trip valve from closing.

To ensure the trip valve stem is free to move, all trip valves should be manually exercised online. The recommended frequency is once per month.

All turbine trip valves should be provided with manual exercisers to allow this feature. Facts concerning manually exercising a turbine while online:

  • Trip valve is only as reliable as valve to move
  • Should periodically (minimum one per month) exercise valve to ensure movement
  • Exercisers will not trip turbine
  • If valve does not move, must be remedied immediately

Protection system philosophies have tended to vary geographically with steam turbine vendors:

  • Most domestic vendors rely only on trip valve to shut off steam supply. (Throttle valves remain open.)
  • European vendors close both trip and automatic throttle valve on trip signal.

Malfunctioning solenoid valve trip control systems have been responsible for catastrophic turbine failures and spurious trips on low control oil pressure due to solenoid valve failures.

The majority of older control oil trip systems used neither parallel trip valves nor online test facilities.

This best practice has been used since 1997, when research into the causes of turbine trips showed that the highest cause of turbine trips were improper functioning of the solenoid trip valves in single and parallel trip systems.

trip oil pressure in steam turbine

William Forsthoffer

You might also like, doosan škoda supplies 15 mw steam turbine to chemical plant in turkey, two casings of steam turbine leave factory, one by land and another by river, doosan škoda’s steam turbine completes uruguay’s first combined cycle.

Forgot Password?

Our Latest Issues

march-april-2021

  • Subscribe (both print and online options available)
  • Sign up for our free newsletter
  • Register for webcasts (live and on-demand)
  • Download free white papers

trip oil pressure in steam turbine

  • E-Newsletter
  • Privacy Policy

© 2019 MultiMedia Pharma Sciences LLC | All Rights Reserved

Click to Hide Advanced Floating Content

View Cart Checkout

What are the Interlocks for Steam Turbine?

In this article, you will learn the interlocks for steam turbine like drum level high trip, steam pressure, and temperature trip.

For the safe operation of the steam turbine and its Auxiliaries, some protection techniques are needed to be followed these are called interlocks .

Let us see what Steam Turbine is and what Interlocks is

Table of Contents

What is a Steam Turbine?

A Steam Turbine is a device that is used to generate Electricity by using super-heated steam along with the generator and alternator .

The steam turbine is also known as the prime mover.

 What is an Interlock?

An Interlock is a function that makes two or more machines or devices mutually dependent on each other to prevent the damage of machines or devices from undesired conditions. The machines or devices may be electrical, electronic, or mechanical devices.

Interlocks can be considered as start permissive of any equipment, or trip.

What is Protection?

The Possibility to Prevent the Damaging of any Equipment or a system or a machine.

Protection is a necessity to safeguard the machine against undesired damages of machines or equipment and abnormal deviation of process parameters to unacceptable values

 Types of interlocks

In general, we consider mainly two types of interlocks

  • Process Interlock
  • Safety Interlock

Why Interlocks?

The main purpose of interlock is to protect or safeguard the equipment against abnormal deviation of process parameters to unacceptable values.

Interlocks are usually made and controlled by suitable sensors and probes provided to avoid unusual damages and problems.

Also Read: Turbine Supervisory Instrumentation

 Turbine Protection System

The main purpose of the turbine protection system is to trip the turbine immediately by stopping and controlling the valves of the HP & LP turbine thereby cutting off the Steam Supply using Main Trip Valves and Solenoid valves.

Steam Turbine Interlocks

So let us see what are the interlocks required for the safe operation of steam turbine .

The below SCADA graphics shows the list of steam turbine interlocks.

Steam Turbine Interlocks

Drum level must be maintained and it should not go high, if it reaches a higher level, there are chances to trip the turbine due to carry-over of water droplets mainly called moisture in the main steam. (shown in below figure)

Drum Level High High Trip

If the Main Steam Pressure PT 5101 B goes high of 124 kg/cm 2 the turbine gets tripped to protect the turbine’s internal casing from high-pressure damage.

If the Main Steam Pressure PT 5101 A goes low of 51.5 kg/cm 2 the turbine gets tripped to protect the turbine internal casing from saturated steam. (shown in below figure)

Turbine Main Steam Pressure High Trip

If the Main Steam temperature TT-5401 B goes high of about 570 o C the turbine gets tripped to protect turbine internals from creep failure.

If the Main Steam temperature TT-5401 A goes low of about 372 o C the turbine gets tripped to protect the turbine from uneven expansion and moisture content present in steam. (shown in below figure)

Steam Temperature Trip

If the Bearing temperature goes high (>110 o C) the turbine gets tripped to protect against bearing failure.

If the Turbine Shaft Vibration goes high of 99 microns the turbine gets tripped to protect against Bearing failure and other Secondary system operation interruptions for a long time. (shown in below figure)

Bearing Vibration Probes are provided on almost every bearing for measuring bearing vibration (sensor types – displacement/velocity/or Acceleration).

Turbine Shaft Vibration High Trip

Turbine trips on high axial displacement to protect turbine internals from rubbing and damage.

If the Lube Oil Pressure PI-506 goes low 1.8 kg/cm 2 the turbine gets tripped to avoid damage on bearings indicating Low Lube Oil Pressure.

Turbine trips on low vacuum or high exhaust pressure to avoid damages on rotor blades.

If the Vacuum breaker valve opens the turbine gets tripped to reduce the speed of the rotor within min time to prevent loss to turbine bearings and their internal parts

If the Hot well level goes high the turbine gets tripped to prevent the turbine from entering water into the turbine. (shown in below figure)

Hot well Boiler Trip

If the bearing temp goes high the turbine gets tripped because high back pressure on the rotor creates reaction force on rotor movement.

If Lube Oil temperature goes low the turbine gets tripped to prevent Bearing Damage and an unusual rise in bearing vibration.

If the Lube oil Temperature goes high the turbine gets tripped to prevent Failure of the C.W. system.

Over speed – Trip (controlled by Voting logic – 2 out of 3 and  4 out of 6 in case of  3 sensors or 6 sensors used ).

The turbine gets tripped If the Condensate Extraction pump (CEP) and Vacuum pumps  are unavailable or damaged

The turbine gets tripped if the Control oil or Hydraulic oil pressure goes low

Software Details

The following are the details of distributed control system ( DCS )

  • Model: AC900F

Turbine Details

  • Make                                       :   Siemens
  • Steam Turbine Type                :   SST-300 (CE2L/V36D3)
  • Turbine Number                     :   3, 21, 15, 465
  • Year of Construction               :   2015
  • Rated Turbine Speed              :   8300 rpm
  • Rated Generator Speed          :   1500 rpm
  • Output Power  in MW            :   15 MW
  • Inlet Steam Temp                   :   535 o C
  • Inlet Steam Pressure              :   105 Kg/cm 2
  • Exhaust Steam Temp              :   47 o C
  • Exhaust Steam Pressure         :   0.1 Kg/cm 2

Interlock Codes  

There are some interlock codes for certain conditions. Listed below.

  • 86G0VX:  Governor Heavy Fault
  • 5ET:  Remote Trip
  • 5ETH:  Hand Trip
  • 12T:  Over Speed Trip
  • 63QLLX:  Lube oil Pressure Low
  • 33QLL: Oil reservoir level low         
  • 63CES3: 3 rd extraction steam Pressure High Trip
  • 63XSHH: Exhaust steam pressure high trip
  • 39VGFHH: Generator front shaft vibration high Trip.
  • 39VWRHH: R/G wheel rear vibration high trip
  • 39VWFHH: R/G wheel front vibration high trip
  • 39VPRHH: R/G Pinion rear vibration high trip
  • 39VPFHH: R/G Pinion front vibration high trip
  • 39VTRHH: Turbine rear shaft Vibration high temp
  • 39VTFHH: Turbine rear shaft Vibration high temp
  • 39DHH: Turbine Axial Displacement High High
  • 39VGRHH: Generator rear shaft vibration High High  
  • 38TTIAHH: Turbine Thrust Bearing Active side temp High High
  • 38TTAHH: Turbine Thrust Bearing Active side temp High Trip
  • 38TFHH: Turbine Front Side Bearing Temperature High trip.
  • 38TRHH: Turbine Rear Side Bearing Temperature High trip.
  • 38PFHH: R/G Pinion front bearing temperature High trip
  • 38PRHH: R/G Pinion Rear bearing temperature High trip
  • 38WFHH: R/G Wheel front bearing temperature High trip
  • 38WRHH: R/G Wheel Rear bearing temperature High trip
  • 33HWHH: Hot Well Level high trip
  • 63SLL: Inlet Steam pressure Low Trip
  • 26SLL: Inlet Steam Temperature Low Trip

If you liked this article, then please subscribe to our YouTube Channel for Instrumentation, Electrical, PLC, and SCADA video tutorials.

You can also follow us on Facebook and Twitter to receive daily updates.

  • What are Oil Burners?
  • Ash Handling System
  • Steam Ejector Principle
  • Boiler Coal Feeding System
  • Turbine Troubleshooting Tips

Recommended Articles

What is Indicator ?

Why Use a Current Loop?

Process Switches and Alarms

DCS versus PLC Architecture

How to Import PlantPAx Library?

What is Instrument Hook Up Diagram ?

Distributed Control System Interview Questions

What is PV Tracking ?

Alarm and Trip Systems

Relay Operation, Types, Symbols & Characteristics

Leave a Comment Cancel reply

More articles.

System Cabinet Health Checks – PLC and DCS Industrial Automation

Stroke Checking Procedure for GCV, SRV, IGV, and LFBV

De-energize to Safe Loop philosophy

Control Modes of Air Handling Unit (AHU) – HVAC Basics

Readings Mismatch between Field & Control Room ? Why

Questions on Ratio Control System

Introduction to PlantPAx Distributed Control System

How to Wire a Field instrument to Control Room with Example

How to Configure a Smart Transmitter Using a HART Communicator?

Jump to content

  • Other Content:
  • Most Active Topics
  • New Releases
  • Popular Articles
  • Process Engineering
  • Process Design
  • Process Safety
  • Legacy Newsletters
  •      Sign In    
  • Create Account
  • Search section:
  • New Content
  • Industrial Forum
  • Process Heat Transfer
  • Student Forum
  • Refining Forum
  • Simulation Forum
  • Relief Devices Forum
  • Tank Venting Forum
  • Status Updates
  • ChE Express
  • Community Blog
  • Ankur's Blog
  • Separation Technology
  • Calcs and Tips
  • Heat Transfer
  • Maint/Repair
  • Bulk Solids
  • Other Topics
  • For Students
  • Physical Properties
  • Excel Spreadsheets
  • Article Supplements
  • Hall of Fame
  • Technical FAQ

trip oil pressure in steam turbine

  • Cheresources.com Community
  • → General Chemical Engineering Forum
  • → Industrial Professionals

Featured Articles

Check out the latest featured articles.

trip oil pressure in steam turbine

File Library

Check out the latest downloads available in the File Library.

trip oil pressure in steam turbine

New Article

Product Viscosity vs. Shear

trip oil pressure in steam turbine

Featured File

Vertical Tank Selection

trip oil pressure in steam turbine

New Blog Entry

Low Flow in Pipes - posted in Ankur's blog

trip oil pressure in steam turbine

Steam Turbine Trip Due To Ll Steam Inlet Pressure

  • You cannot start a new topic
  • Please log in to reply

Gold Member

Posted 27 October 2017 - 02:40 AM

We have a compressor drive by Steam Turbine with High pressure superheated steam (P:40 barg & T:400 DegC). The exhaust steam pressure is 5 Barg and 200 DegC. There is trip in case of exhaust steam pressure reach to 2 barg, while there is no trip signal given in cacse of Inlet steam pressure Low Low. Is there any reason or simly depend on exhaust steam pressure. The steam turbine is a back pressure turbine and there is no steam drwan from interstage.

  • Back to top

trip oil pressure in steam turbine

  • ChE Plus Subscriber
  • 4,930 posts

Posted 27 October 2017 - 03:29 AM

  We have a compressor drive by Steam Turbine with High pressure superheated steam (P:40 barg & T:400 DegC). The exhaust steam pressure is 5 Barg and 200 DegC. There is trip in case of exhaust steam pressure reach to 2 barg, while there is no trip signal given in cacse of Inlet steam pressure Low Low. Is there any reason or simly depend on exhaust steam pressure. The steam turbine is a back pressure turbine and there is no steam drwan from interstage.  

I think with a fixed turbine speed, low pressure trip on exhaust steam which is to be considered avoiding condensate generation inside the turbine will also cover the low pressure concern of incoming steam at the inlet. Hence no need to a separate low pressure trip at the inlet.

Posted 27 October 2017 - 03:38 AM

It is a variable speed turbine.

Posted 27 October 2017 - 04:01 AM

Hence 2 barg as the trip set point for exhaust steam pressure is the lowest tolerable pressure corresponding to the lowest inlet steam pressure at maximum turbine speed...!

#5 Bobby Strain

trip oil pressure in steam turbine

  • 3,526 posts

Posted 27 October 2017 - 09:14 AM

There is no problem if the inlet pressure is low. However, as Naser indicated, low exhaust pressure can result in condensation. This may damage the blades. And high velocity at the low pressure may also damage the blades.

Similar Topics

  • Guidelines / Rules for Posting

trip oil pressure in steam turbine

  • Mark all as read

Community Forum Software by IP.Board

' style=

  • Need an account? Register now!
  • Username or email:
  • Forum Password I've forgotten my password
  • Remember me This is not recommended for shared computers
  • Privacy Policy

TW366387B - A trip oil system for a fuel supply coupled to a gas turbine - Google Patents

  • Global Dossier

Classifications

  • F — MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01 — MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D — NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D21/00 — Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for
  • F01D21/16 — Trip gear
  • F01D21/18 — Trip gear involving hydraulic means
  • F02 — COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C — GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C7/00 — Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
  • F02C7/22 — Fuel supply systems
  • F02C7/232 — Fuel valves; Draining valves or systems
  • F02C9/00 — Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants
  • F02C9/26 — Control of fuel supply
  • F02C9/46 — Emergency fuel control

Applications Claiming Priority (1)

Publications (1), id=23255682, family applications (1), country status (4), families citing this family (17), family cites families (8).

  • 1994-10-13 US US08/322,623 patent/US5561976A/en not_active Expired - Fee Related
  • 1995-08-11 TW TW084108402A patent/TW366387B/en not_active IP Right Cessation
  • 1995-10-09 JP JP26059795A patent/JP3797688B2/en not_active Expired - Lifetime
  • 1995-10-12 KR KR1019950035041A patent/KR100391743B1/en not_active IP Right Cessation

Also Published As

Similar documents, legal events.

IMAGES

  1. Steam Turbine Siemens SST-5000 Explained

    trip oil pressure in steam turbine

  2. Steam Turbine Parts and Components

    trip oil pressure in steam turbine

  3. Trip Valve Principle

    trip oil pressure in steam turbine

  4. Steam Turbine Siemens SST-5000 Explained

    trip oil pressure in steam turbine

  5. Overview of Steam Turbines: Operation, Types, Components, and Maintenance

    trip oil pressure in steam turbine

  6. Steam Turbine Governing System

    trip oil pressure in steam turbine

COMMENTS

  1. How steam turbine protection system works

    The devices that trip the turbine internally directly reduce the control oil pressure, causing a trip valve closure without the need of a solenoid valve (external trip method). Two popular types of steam turbine shut off valves are available and both use a high spring force, opposed by control oil pressure during normal operation, to close the ...

  2. Protection of steam turbines using reliable solenoid trip valves

    That is, they directly reduce the control oil pressure causing a trip valve closure without the need of a solenoid valve (external trip method). Two popular types of steam turbine shutoff valves use a high spring force, opposed by control oil pressure during normal operation, to close the valve rapidly on loss of control oil pressure.

  3. Operator's Guide to General Purpose Steam Turbines

    Back Pressure Steam Turbines 31 2.2.1 Radial and Th rust Bearings 31 ... 13.4.3 Oil Analysis as it Applies to Steam Turbines 247 13.4.4 Formation of Sludge and Varnish 248 13.4.5 Steam Piping and Supports 249 13.4.6 Steam Turbine Supports 250 13.4.7 Overspeed Trip Systems 251 13.5 Other Inspections 252

  4. Turbine lubrication: Practical guidelines

    Steam turbine lube oil system is usually required to provide oil for trip-and-throttle valve, governor system, power cylinder or similar accessories (combined pressure lubrication and control oil unit). Steam turbine lubricants must readily shed the water. Water in the steam turbine train oil reservoir is from one of three following sources.

  5. PDF Resolving Turbomachinery Trains Low-Low Lube & Seal Oil System Pressure

    Main Oil Pump: Steam Turbine or Motor Drivers Initiate Lube-Seal Oil Pump Trips 1. Sudden Trips Overspeed Latch: Root cause of sudden trips of steam turbine driven main lube oil pumps: The most common factor found is that the main steam turbine driven pump undergoes a shutdown caused by turbine overspeed trip linkage suddenly dropping which

  6. PDF TURBINE OVERSPEED SYSTEMS AND REQUIRED RESPONSE TIMES

    The loss of trip oil header pressure may directly move a trip mechanism or may operate through a hydraulic circuit to cause stop valves to close. In general, the trip oil system follows a common design regardless of the sensing mechanism although the trip mechanism designs on the steam valve can vary. The trip

  7. PDF STEAM TURBINE TRIP SYSTEM UPGRADES

    oil pressure diaphragm and the hand trip knob. In addition, the action of the oil dump valve causes the governor valve to close. By Sydney Gross and Scott MacFarlane Figure 1 Once the system changes have been decided; we can look at the physical changes to be made to the turbine. Aside from removing the old obsolete parts

  8. PDF STEAM TURBINE TRIP & THROTTLE VALVE

    STEAM TURBINE STEAM TURBINE TRIP & THROTTLE VALVE By Sydney Gross The T&T valve, as it is often referred to on industrial turbines, is located upstream of the steam chest ... responds to loss of oil pressure by releasing the latch and allowing the valve to shut. Closing time is on the order of less than ½ second. Loss of oil pressure to the

  9. Steam Turbine Oils

    Steam turbine oil facilitates reliable rotation of the large turbine rotors by providing two major functions, lubrication and heat removal. ... Large high steam pressure turbines typically rotate at 1,800 or 3,600 rpm for 60 Hz generators and 1,500 or 3,000 rpm for 50 Hz generators. ... The emergency trip valve, sometimes called the overspeed ...

  10. PDF Steam turbine lube oil system monitoring and control

    Steam turbine Monitoring, Lube oil temperature, Lube oil Pressure, Steam turbine Control, Lube oil Pumps, PI Controller. 1,2Department of Electrical and Electronics Engineering, Bharath Institute of Higher Education and Research, Chennai-600073, Tamil Nadu, India. c 2020 MJM.

  11. Essentials of Steam Turbine Design and Analysis

    This process can be followed on an enthalpy-entropy (H-S) diagram, known as a Mollier chart. In the example diagram (), the path from Point 1 to Point 2 represents typical BPST operation at a chemical plant, pulp and paper mill, oil refinery, or food processing facility; superheated 600-psig steam at 700°F (Point 1) expands as it passes through the turbine and is exhausted at a pressure of 50 ...

  12. Steam Turbines: Basics, Types, Selection, Components, Construction

    Master Trip. LP Trip. Low Lubricating Oil Pressure Trip. High Bearing Temp. Trip. High Vibration Trip. High Axial Displacement Trip. Relief Valve in Exhaust; Techniques to Improve Steam Turbine Efficiency. Various techniques are employed to maximize steam turbine efficiency, each designed to attack a specific loss mechanism. For example:

  13. PDF Turbine Overspeed Trip Protection

    • "A" or "B" trip signal is seen, then the turbine trips. • "A" or "B" loss of signal or power, an alarm is given but the turbine remains running. • "A" and "B" loss of signal or power, the turbine trips. Figure 1 is the simplest system that can be used for a "special purpose steam turbine."

  14. Control Oil Pressure

    Best Practice 7.31. Check the control oil accumulator every three months to ensure desired transient response, in order to prevent a steam turbine trip on low control oil pressure.. In order to ensure proper transient response, an accumulator must maintain the proper nitrogen pre-charge pressure and have the bladder intact (rupture free).

  15. Practical issues in steam turbines used in oil and gas applications

    Run down tank shall be located at higher level than the steam turbine to ensure sufficient static oil pressure to the bearings during coast down. This article contains excerpts from the paper, "Tutorial on large steam turbine systems in oil and gas applications," by Mounir Mossolly, Emmanuel Bustos and Guillaume Herve at the 2017 Turbomachinery ...

  16. To remove the steam turbine tripping from Trip Oil

    Apr 27, 2013. #1. Due to the malfunction of trip oil pressure switch the steam turbine got tripped. The trip oil is used to overcome the spring action of emergency stop valve (ESV) by which the steam goes inside the turbine. Process people are saying to remove the tripping of turbine from trip pressure low. They are saying that due to the less ...

  17. PDF SAFE LOGIC, TRIP PERMISSIVES AND STEAM TURBINE PROTECTIONS

    turbine needs to be avoided in any case. The turbine Protection System can be actuated by any of the following trip system:- 1. Hydraulic Trip System 2. Electrical Trip System Both the trip system when initiated act on the hydraulic control system and cause trip oil to drain which in turn closes the emergency stop valves & control valves. Fig 3.

  18. Protection of steam turbines using reliable solenoid trip valves

    That is, they directly reduce the control oil pressure causing a trip valve closure without the need of a solenoid valve (external trip method). Two popular types of steam turbine shutoff valves use a high spring force, opposed by control oil pressure during normal operation, to close the valve rapidly on loss of control oil pressure.

  19. What are the Interlocks for Steam Turbine?

    Drum Level 2oo3 Logic. If the Main Steam Pressure PT 5101 B goes high of 124 kg/cm 2 the turbine gets tripped to protect the turbine's internal casing from high-pressure damage.. If the Main Steam Pressure PT 5101 A goes low of 51.5 kg/cm 2 the turbine gets tripped to protect the turbine internal casing from saturated steam. (shown in below figure) Turbine Main Steam Pressure High Trip

  20. Steam Turbine Trip Due To Ll Steam Inlet Pressure

    The exhaust steam pressure is 5 Barg and 200 DegC. There is trip in case of exhaust steam pressure reach to 2 barg, while there is no trip signal given in cacse of Inlet steam pressure Low Low. Is there any reason or simly depend on exhaust steam pressure. The steam turbine is a back pressure turbine and there is no steam drwan from interstage.

  21. A trip oil system for a fuel supply coupled to a gas turbine

    A trip oil system automatically controls the fuel shut-off valves in an industrial gas turbine. The trip oil system applies hydraulic pressure to actuate and hold open a fuel shut-off valve to that fuel flows to the combustor of the gas turbine. When the trip oil system relieves the hydraulic pressure, the fuel shut-off valve closes and stops ...