Steam Turbine Questions and Answers of Power Plant : JobExamHub

Steam Turbine Questions and Answers of Power Plant are collection of most important questions and answers. These question are important for power plant job interviews and many BOE exams. I hope these ‘Steam Turbine Questions and Answers‘ give you extra ordinary knowledge of steam turbine and power plant.


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1 Steam Turbine Questions and Answers

Steam Turbine Questions and Answers

Steam turbines are used in many different industries and applications, from providing the power for ships to generating electricity in power plants. They can operate on a variety of fuel sources, including coal, natural gas, nuclear power, and even solar energy.

Steam Turbine Questions and Answers
Steam Turbine Power Plant

Q. What is steam turbine in power plant?

Ans. A steam turbine in a power plant is a device that converts the thermal energy of steam into mechanical energy by spinning a turbine blade. It is usually used to generate electric power in a power plant.

Q. Why the U loops do is used at the Inter condenser drain line of ejector?

Ans. U loop is to seal the ejector and steam condenser pressure as there is very less pressure difference around 0.25 to 0.3 kg/cm2. So for such low pressure difference U loop seal is economic and practical.

Q. How the lower vacuum increased steam consumption of turbine?

Ans. Lower vacuum is nothing but higher exhaust temperature, so turbine exhaust high temperature steam to condenser leading to loss in heat. Therefore, in order to maintain provided load set value turbine use more steam. And also higher pressure in condenser creates reaction force on turbine rotor making it to drag more steam to maintain its speed and torque as per load.

Q. What do you mean by steam turbine supervisory system?

Ans. Turbine is known as high speed machine, its work and performance is monitored with the help of supervisory system. Supervisory system include – Speed probes, Vibration probes, Axial displacement probes, Differential expansion probes, Bearing temperature TCs or RTDs, Casing temperature TC, Casing expansion.

Q. What is back pressure steam turbine?

Ans. A back pressure steam turbine is a kind of steam turbine. It is usually used to extract energy from a steam source, like a boiler. The turbine controls the pressure and flow of steam in the system by utilizing the exhaust steam to generate power. This kind of turbine is beneficial due to its ability to extract the maximum amount of energy from the steam source while required still maintaining and a safe operating pressure.

Q. Why wheel chamber pressure dropped?

Ans. It’s possible that the wheel chamber pressure dropped because of a reduce in air pressure in the chamber. It can be happen if the turbine’s wheel chamber is not properly sealed, or if there is a leak available somewhere in the system. It’s also possible that the temperature in the wheel chamber has reduced, which can create a corresponding lose in pressure.

Q. Where the pressure relief valves are connected at ejector system?

Ans. There two pressure relief valve in SJAE (steam jet air ejector) one is fitted at ejector nozzle chamber and other is fitted at condensate water outlet line.

Q. What are the reasons for high exhaust temperature in team turbines?

Ans. High exhaust temperature is due to – lower vacuum in the condenser, turbine running on partial load, overload on steam condenser, ejector U seal loop broken

Q. Why the oil coolers are mounted before lube oil filter?

Ans. The oil DP may vary at filters due to temperature difference, so oil is initially passed through cooler, where its temperature decreases to constant operating point then it is passed through filters.

Q. What is the auxiliary equipment required for operating steam condenser?

Ans. Cooling water re circulation pump (centrifugal), air pump or steam ejector to remove air and other non condensing gases from the condenser, an extraction pump (centrifugal) to remove condensate from the condenser.

Q. Why it is required to measure the casing temperature of turbine?

Ans. The making material of casing of turbine is thick alloy. So more temperature difference varied between inner part and Outer part of the turbine casing and it may cause distortion. So in order to ensure the exact casing temperature being measured. The temperature difference should not > 50 degrees Celsius between top and bottom turbine casing thermocouples.

Q. What are the causes of foam formation in lube oil?

Ans. Reasons for formations are- air intake in lube oil, low oil level in MOT, excessive splashing of oil in bearings, insufficient size of lube oil return line

In order to rectify this anti-foam agents are added into oil sump.

Q. Where are the two methods of oil centrifuging?

Ans.

  • Purification
  • Clarification

Q. What is purification?

Ans. It is separation of two immiscible liquids having different specific gravity and is useful for the removal of the solid particles with specific gravity higher than those of the liquids. In purification method some amount of solids are removed along with moisture.

Q. What is clarification?

Ans. It is the process of separation of solid particles from oil or any other liquid. In clarification process also some amount of moisture is removed along with solids.

Q. What is the soaking period in steam turbines?

Ans. During initial starting of steam turbine is permitted to expand evenly and smoothly by permitting sufficient time related to warm up, this period is known as soaking period. This is done for allow uniforms expansion of turbine casing, rotor, and other internal parts.

Q. How do you choose filter size of lube oil and control oil filters?

Ans. Filter size is taken in lube oil filter around 25 to 40 microns. Filter size is taken in control oil filter around 10 to 25 microns.

Q. How do you measure the steam turbine casing expansion?

Ans. Generally, it is measured with the equipment of LVDT (linear variable displacement transducer).

Q. What is the difference between control oil and trip oil?

Ans. Oil delivered by control oil pump (previously mop was used for both live and control oil applications) is be bifurcated into two systems. After one oil passes through some of protection relays to open ESV is called trip oil and other goes to operation of HP, MP, LP valve actuators called as control oil.

Q. What is the care should we taken while turbine is running on no load?

Ans. In no load operation, no steam must be removed from extraction or bleed; turbine should run on pure condensing mode.

Q. How steam turbine works in power plant?

Ans. A steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. In a power plant, a steam turbine is connected to a generator, which converts the mechanical energy of the turbine into electrical energy.

The process works by heating water in a boiler, creating steam in the boiler, and then allowing the steam to expand in a turbine. The expansion of the steam causes the turbine blades to rotate, which in turn rotates the output shaft. The output shaft is then connected to a generator, which converts the mechanical energy of the turbine into electrical energy.

Q. Why do the float valve are used at the after condenser of condensate line of ejector?

Ans. Float valve is used to seal the ejector and steam condenser pressure as there will be around 0.89 0.95 kg/cm2 pressure difference.

Q. What happens if vacuum dropped in ejector of steam turbine?

Ans. If a vacuum is dropped in the ejector of a steam turbine, it can put the turbine under an excessive amount of stress and cause it to malfunction. Depending on the severity of the situation, the turbine may need to be shut down and taken apart to repair any damage that may have occurred. It is important to take the necessary safety precautions and contact a professional to assess the situation before attempting any repairs.

Q. What is the coast down time in steam turbines?

Ans. It is the time taken by a steam turbine rotor to come down from its rated speed to zero speed after trip or shutdown of turbine. Turbine speed starts reducing once ESV closes. It depends on vacuum in the condenser. If vacuum is more it takes more time to come down to rest position.

Q. What is the significance of gland sealing? When to make changes in gland steam after vacuum pulling or before?

Ans. The purpose of gland selling is to prevent air enter in the vacuum system during pulling vacuum. The team is applied on both labyrinth glands and even at control valve glands. The pressure maintains is around 0.1 kg/cm2.

Gland steam can be changed according to turbine operation conditions:-

Cold start up- In this turbine is in atmospheric temperature, hence gland steam is charged after vacuum pulling at vacuum say – 0.2 to – 0.5 kg/cm2. There may be chances of creating thermal stresses, If gland sealing is done before vacuum pulling.

Hot Start up- Gland sealing is charged even before vacuum pulling. Charging the gland seal steam after vacuum pulling may cause cold air shock in the glands which may lead to rotor distortion.

Q. Why vacuum drop in ejector of steam turbine?

Ans. Vacuum drop in ejector of steam turbine is necessary to create a vacuum in the condenser. This vacuum helps to reduce the exhaust steam pressure, which in turn increases the power output of the turbine. It also helps to reduce the fuel consumption and reduce the overall cost of operation.

Q. Why condensate extraction pump starts in auto in steam turbine?

Ans. Condensate extraction pumps are used to remove condensate (water) from the steam turbine. The pump is typically started automatically when the steam turbine is activated. This ensures that the condensate can be removed from the turbine efficiently, preventing any damage from occurring due to excess water accumulation.

Q. Why there are two RTDs for turbine pinion bearing temperature measurement?

Ans. If turbine rotation is clockwise (view from turbine font) then the bottom part of the bearing is on higher load and if it is in anti clock wise direction top part is under load. So, some temperature difference varies between these two RTDs.

Q. What are the reasons for high a barring temperatures and vibrations?

Ans. Overloading of the turbine, high lube oil temperature, foreign materials in lube oil, load fluctuation, more clearance in the bearing.

Q. What is difference between condensate type steam turbine and back pressure type steam turbine?

Ans. The primary difference between these two (condensate type and back pressure type steam turbines) is the method in which both extract energy from the steam. Condensate kind of turbine is designed to extract maximum energy from the steam, but back pressure kind of turbine is designed to extract a ‘specific amount of energy’ and then release the rest steam at a higher pressure. Condensate kind of turbine can generate more power than back pressure kind of turbines, but they are also more expensive to operate since they need excess energy to run. Back pressure kind of turbine is more efficient and cost-effective, but they generate less power than condensate kind of turbines.

Q. What is wheel chamber pressure in steam turbine?

Ans. In a steam turbine, wheel chamber pressure is the pressure of the steam in the provided chamber in turbine. That chamber located between the turbine’s rotors and the turbine’s nozzles. Usually, It measured in pounds per square inch (PSI) or in kg/cm2. This wheel chamber pressure is critical in the operation of the steam turbine, as it dictates the steam turbines output. Too much wheel chamber pressure can create the turbine to run inefficiently, while too low wheel chamber pressure can create the turbine to lose power or even fail. It is very important to monitor the wheel chamber pressure of steam turbine to ensure optimal turbine performance.

Q. What is the purpose of hot well re-circulation line in CEP condensate line?

Ans. Significance of hot well re-circulation line- To provide minimum flow to CEP pump, to safe guard ejector tubes due to lack of cooling during low loads on turbine due to less or no water flow through the tubes.

Q. Why the control oil temperature is more than lube oil or why control oil is not cooled in coolers?

Ans. To maintain low viscosity of the oil, control and governing system internal parts have very low operating clearance. So in order to maintain that control oil is not cooled and maintained its temperature around 60 degrees Celsius.

Q. What are effects of air leakage in condenser?

Ans. It increases back pressure on the turbine so there is less heat drop and low thermal efficiency of plant, steam will condensate at lower temperature and that will require greater amount of cooling water, it reduce the rate of condensation of steam because air having poor thermal conductivity. So impairs the heat transfer from steam-air mixture.

Q. How vacuum is measured in condenser usually?

Ans. It is measured by ‘burden pressure gauge’ in which pressure is measured in ‘mm of mercury’ below atmospheric pressure. 1 atmospheric pressure = 760 mm of Hg

Q. Where will be the highest steam velocity at full load operation of the steam turbine?

Ans. At full condensing mode velocity of steam is more at exhaust end point of the steam turbine as compared to exhaust duct. Because exhaust duct has more area as compared to inlet steam line area.

Q. Why wheel chamber pressure increased?

Ans. Wheel chamber pressure can improve for a number of causes, such as improve in the amount of air in the wheel chamber, a blockage in the exhaust, a worn or damaged bearing, or improve in friction. It is need to inspect the entire system to determine the exact reason of the improved pressure.

Q. What is the quantity required of lube oil for jacking oil pump (JOP)?

Ans. It is 8 to 10% of total lube oil flow to their bearings. Generally JOP line is given to alternator and even at both alternator and turbine to facilitate lifting of rotor during rotation of shafts to avoid friction between rotor and bearings.

Q. What is the quantity required to lube oil for gearbox?

Ans. It is 60 to 65% of total lube oil flow

Q. What is the quantity required to lube oil for turbine?

Ans. It is 22 to 25% of total lube oil flow

Q. How servo motors work in steam turbine?

Ans. In steam turbines, servo motors are used to regulate the flow of steam as it get entry to the steam turbine. The servo motor is controlled by a controller, which monitors the temperature, pressure, and flow of the steam to ensure that the steam is being used as efficiently as possible. The servo motor then adjusts the location of the valve in order to regulate the flow of the steam get enter to turbine. By doing this, the turbine is able to produce more power and operate more efficiently.

Q. On what trip interlock protection vacuum breaker valve gets open?

Ans. Vacuum breaker valve in turbine opens on activation of given below trip interlocks:

  • High bearing temperature
  • High bearing vibration
  • High rotor Axis displacement
  • Differential expansion
  • Over speed

Q. What is power factor?

Ans. Actual OR real power (KW)/ Apparent power (KVA). The power factor should be less than 1.

Q. What is duplex filter in steam turbine?

Ans. In a steam turbine, a duplex filter is a type of filtration system designed to protect the steam turbine components from damage due to the availability of contaminants in the steam. It contains of two sets of filters, usually of different pore sizes, that are linked in series. The larger-pore filter traps the bulk of the contaminants, while the smaller-pore filter avoids the remaining smaller particles. Duplex filters are effective at decreasing the risk of erosion and corrosion of steam turbine components, which can decrease their efficiency and lifespan.

Q. Why it is necessary of oil centrifuging in turbine lube oil system?

Ans. Due to atmosphere moisture entering, turbine oil gradually gets bad effects through steam turbine bearing sealing system and also partial oxidation of oil occurred. So, oil requires to purify for maintaining its property. Also oil content some dissolved solids particles created during its service, so that must be removed timely to ensure good life of steam turbine bearings and actuator system.

Q. Why do the steam turbine front side bearing oil lines have expansion bellows?

Ans. Because steam turbine casing got expansion towards front side only. In some steam turbines expansion bellows are fitted for both front and rear bearing. In case of generator and gearbox oil line, expansion bellows not provided.

Q. What is the purpose of casing drains in steam turbine?

Ans. Casing drains in steam turbines are designed to collect and remove condensate or other liquid build-up that can accumulate in the turbine housing. This build-up can cause corrosion, vibration, and inefficient operation of the turbine. By removing the liquid, the casing drains help to improve the performance and longevity of the turbine.

Q. Why do you control the outlet valve of oil cooler water line for controlling the lube oil temperature instead of water line inlet?

Ans. It is for avoiding starvation of tubes due to no loss or less flow of water into the tubes.

Q. What is governor in steam turbine?

Ans. A governor in a steam turbine is a device that regulates the speed of the turbine by controlling the steam pressure entering it. By controlling the steam pressure, the governor can adjust the speed of the turbine to match the load requirements of the system. The governor also monitors the turbine speed to make sure it is not running too fast or too slow, which can cause damage to the turbine.

Q. Why do the tubes and control oil supply lines are making with stainless steel (SS) material and material of drain /return oil line is Carbon Steel (CS)?

Ans. Supply lines are fitted to bearings and actuators and they require of supply contaminant/ bur free oil. Normally, SS pipeline material do not create rust and also burrs, while carbon steel pipe lines formed rust and burs. Created rust or burs in CS Steel collect in MOT (main oil tank) and then removed by centrifuging.

Q. What is the purpose of twin oil coolers in steam turbine?

Ans. In steam turbines, twin oil coolers are used to help regulate the temperature of the oil used by the steam turbine. By having two coolers, the steam turbine is able to maintain a consistent temperature, permitting the steam turbine to run more efficiently and last longer. Additionally, the twin coolers can be used to increase the overall safety of the steam turbine by triggering safety shutdowns in the event of an oil temperature spike.

Q. What clearance should be between rotor and casing diaphragm?

Ans. It is 0.6 to 1.5 mm

Q. What are the functions of oil vapor extraction fan (OVEF)?

Ans.

Remove the oil mist formed in main oil tank (MOT), maintain slight vacuum 22 – 30 mmwc in MOT for easy drain of lube oil from turbine bearings.

Q. What is the purpose of accumulator in lube oil system?

Ans. The accumulator in a lube oil system has two main purposes. First, it works as a reservoir to collect excess lube oil and maintain constant pressure in the whole system. It aids to ensure the oil supply is consistent, even under changing load and operational conditions. Secondly, the accumulator aids to filter out any contaminants or debris in the oil, which can create damage to the system’s components.

Q. What is condenser?

Ans. It is heat exchanger where steam is condensed either in direct contact with cooling water or indirect contact with cooling water. Jet condenser is direct contact heat exchanger and surface condenser is indirect contact heat exchanger.

Q. What are prime functions of condenser?

Ans. It reduce the back pressure upon the turbine to a considerable degree. therefore, the work done per kg of team during expansion is increased. the exhaust steam condensate can be recycled as boiler feed water.

Q. Why vacuum is maintained in the steam condenser?

Ans. By maintaining the vacuum in steam condenser, the efficiency of the steam power plant can be increased. As greater the vacuum in the system then greater will be the enthalpy drop of steam. Therefore, more will be available per kg of steam condensing and secondly non condensing gases can be removed from the ‘condensate steam circuit’ by pulling and maintaining a vacuum in the steam side. Therefore, the condensate used as boiler feed.

Q. What is vacuum?

Ans. Vacuum means any pressure below atmospheric pressure.

Q. What are the sources of air in condenser?

Ans.

  • Boiler feed water as dissolved gases which carried off by steam of turbine and finally condenser
  • Flanges leakage
  • Cooling water in which air is in dissolve form.

Q. What is a surface condenser?

Ans. It is shell and tube heat exchanger in which steam is condensed on the shell side, while cooling water flows through the tubes. The condensate and cooling water leaves the system separately.

Q. What is down flow type surface condenser?

Ans. In down flow type surface condenser, exhaust steam is admitted to the top of the condenser. It is a tube and shell type cross flow heat exchanger. Cooling water flows through the tubes and extracts heat from the steam. After having condensed on the surface of water tubes, steam is converted into condensate which is discharge from the condenser bottom.

Q. Why condenser tubes failure?

Ans. Due to anaerobic decomposition, organic compounds deteriorated. Therefore, hydrogen sulfide and Ammonia attacks on the surface of condenser tubes.

Q. What are the causes of condenser tube blocks and leakage?

Ans. Increased concentration of organic compounds in the cooling water that promotes microbial activities, low flow velocity of cooling water at condenser inlet, restricted use of chlorine.

Q. How does increased concentration of organic compounds in cooling water lead to condenser tube failure?

Ans. The principal cause of condenser tube failure is internal corrosion. The organic compounds (seaweeds, muscles, algae’s etc) deteriorate through aerobic decomposition releasing hydrogen sulfide and Ammonia which attacks to the tube surface quickly resulting in pitting and inter granular corrosion.

Q. How do the low cooling water velocities contribute to condenser tube failure?

Ans. It increase biological growth and allow muscles, clans and aquatic plants to accumulate on the tube surfaces.

Q. Why chlorine is restricted?

Ans. For environment reason

Q. What is Bio fouling problem and how it can be overcome?

Ans. For this we used a non toxic coating to reduce condenser fouling. For this we use Silicon based resistance coating which proved to the best candidate reducing the frequency of water box and condenser tube cleanings.

Q. What we do if vacuum is too low?

Ans. We increase gland header pressure or to take second ejector in line.

Q. What is vacuum breaker in turbine?

Ans. The purpose of vacuum breaker is to quickly allow air into the vacuum space of the condenser or steam turbine. Vacuum breaker valve usually located at steam turbine or at the condenser shell. Generally vacuum breaker valve reduce the acceleration of the turbine upon loss of load by the generator.

Q. What are the benefits of vacuum breaker valve?

Ans. Benefits of vacuum breaker valve – reduce the vacuum, reduce turbine speed as quickly possible, reduce the possibility of turbine rotor vibration in over speed conditions, and reduce the loss of turbine lubrication oil pressure.

Q. What is generator?

Ans. Generator convert mechanical energy to electric energy. Electric generator works on the principle of Faraday’s electromagnetic induction. The essential part of this principle is the magnetic field. The source of magnetic field is exciter.

Q. What is rotor in steam turbine?

Ans. The rotor is rotating on Electromagnet that requires DC electric power source to excite the magnetic field. This DC power comes from the exciter.

In a steam turbine, rotor is the rotating part that is linked to the blades. It works by transforming the kinetic energy from the high temperature and high pressure steam into mechanical energy, which is then used to the turbine shaft and finally to the power output shaft.

Q. What is the working principle of exciter?

Ans. Exciter is a part of generator system. The electricity generate by generator at output constant voltage and this constant voltage controlled by magnetic field. This magnetic field produced by a DC power source. This DC power source is exciter.

Q. Why barring should be taken 72 hours after shutdown of steam turbine?

Ans. It is for uniformly cooling of rotor, otherwise rotor can be bending.

Q. What happened if hot well level high and what we done?

Ans. Check CEP (condensate extraction pump) suction – discharge. If suction and discharge is okay and section discharge line is not choked then see DM water or makeup water leakage valve. If both CEP started but level not dropped then decrease turbine load.

Q. What happens if lube oil temperature high?

Ans. Bearing temperature increased.

Ans. Then check lube oil temperature and lube oil inlet – outlet oil pressure. Maintain lube oil temperature by inlet outlet isolation valve of lube oil. If isolation valve not fully open then control by isolation valve, if isolation valve fully open then for temperature control change lube oil cooler.

Q. What is dump control valve?

Ans. If gland steam pressure increased then dump valve should be open (if bypass fully open).

A dump valve in a steam turbine is a safety valve that is used to prevent over pressure when the turbine is in operation. It is designed to open when the pressure in the turbine exceeds the set limit, releasing the excess steam to a safe location. This helps to protect the turbine from damage and ensures that the turbine runs safely and efficiently.

Q. If lube oil filter temperature is high?

Ans. If temperature is high then check DP (differential pressure) of inlet – outlet pressure of filter. If DP is high then change lube oil filter.

Q. What is OVEF (oil vapor extraction fan)?

Ans. It extracts vapor from Oil tank. If vapor is not extracted than oil temperature should be increased because the vapor condensate mixed with oil. Increased the temperature can be reason of leakage of bearing oil line.

Q. What is turbine critical speed?

Ans. Speed that between idle speed and rated speed. At this critical speed rotor rotated on oil layer and not load on bearing (front/rear). So rotor cannot be stopped at critical speed. If it is stopped at critical speed then vibration and temperature can be increased. Increased vibration and temperature can damage bearings. Abnormal sounds come at critical speed.

Q. What is electrical trip speed?

Ans. In electrical trip Speed, the RPM of turbine more than rated or normal speed of 10% approx.

Q. What is mechanical trip speed?

Ans. It is more than rated speed of 12 to 15% and also more than electrical speed.

Q. What is gland is steam pressure?

Ans. It is pressure of leakage steam turbine and this is not condensate steam.

Q. What is EOP (emergency oil pump)?

Ans. If MOP stopped and AOP also not work in auto mode then turbine tripped and for lubrication EOP starts in auto.

Q. What is overhead lube oil tank?

Ans. If MOP stopped and AOP also not work in auto mode then turbine tripped and not oil flow for lubrication for rotor then EOP will starts in auto. If EOP pressure less than NRV of OVEH tank line by gravity pressure difference. It is returning oil.

Q. What is JOP?

Ans. (Jacking Oil Pump) starts in beginning and stopped after barring of steam turbine. The pressure of JOP should be minimum 80 kg/cm2. This pressure dropped before bearing by many nozzles and finally it is 2 – 6 kg/cm2.

Q. What is turning gear?

Ans. It used in barring purpose of steam turbine. Turbines (Back pressure and Condensate type) have turning gear. In condensate type turbine, it is MOV based. But in back pressure type turbine, it is motor based.

Q. What is gear box?

Ans. Back pressure type turbine have gear box but condensate type turbine not have gear box. This is due to different design of both steam turbines. In back pressure type turbine, generator and turbine operates with different RPM. But in condensate type turbine generator and turbine work on same RPM.

Q. What happened if GSC cooler choked?

Ans. The gland pressure dropped gradually.

Q. For what, trip oil used in steam turbine?

Ans. Trip oil: used for ESV (emergency stop valve)

Q. For what, auxiliary trip oil used in steam turbine?

Ans. Auxiliary trip oil: used for device protection

Q. For what, secondary oil used in steam turbine?

Ans. Secondary oil: used for operating control valve

Q. For what, auxiliary secondary oil used in steam turbine?

Ans. Auxiliary secondary oil is used for hydraulic governing.

Q. For what, startup oil used in steam turbine?

Ans. Startup oil: used for reset HP, LP, ESV stop valve and releasing the control valve.

Q. Is startup oil and control oil is same?

Ans. Yes, both are same.

Q. Where trip oil and startup oil are used?

Ans. Both are used in ESV (emergency stop valve).

Startup oil reset the ESV. First trip oil opened, then for resetting the ESV startup oil is opened. Startup oil is used in ESV for avoiding stuck or jerk.

Q. What is Condensate Steam Turbine?

Ans. A condensate steam turbine is a kind of steam turbine that utilizes steam as its source of power to drive a generator and make electricity. This turbine works by using the steam produced from boiling water and then using the pressure of the steam to move a turbine and produce rotational energy. The rotational energy is then transformed into electricity, which can be used in a many ways. The condensate steam turbine is a cost effective way and efficient to produce power.

Q. How Condensate Steam Turbine works?

Ans. A condensate steam turbine is a kind of steam turbine that utilizes condensate steam to produce mechanical power. Condensate steam is generated when water got heated and its pressure got increases, pushing this through the system. The turbine has a rotating shaft and linked to the condensate steam. When steam passes through the turbine, then shaft rotate, which in turn powers the machine or generate electricity? The condensate steam turbine is then able to transform thermal energy into kinetic energy, which is used for doing work. This process is called as the Rankin Cycle.

The process get starts with input of high-pressure steam, then passes through the blades of turbine and is fastly exhausted after giving off its energy. The exhausted steam then condensed back into liquid phase by passing it through a cooling system like a condenser. This condensate recycled back into the system to be heated again, thus generating a continuous cycle of energy generation.

The condensate steam turbine has many benefits including cost-effective, being easy to maintain and efficient. Due to conversion of thermal energy into kinetic energy, it can be utilized in much different kind of applications like power production and propulsion.

Q. What are benefits of using a condensate steam turbine?

Ans. Using a condensate steam turbine provides many benefits when compared to others. Condensate steam turbines are known for their low cost and efficiency. In a short period of time, they can generate large amounts of electricity. Additionally, they require less maintenance than other energy generation forms. This makes them cost effective and highly reliable in the long run.

The emissions generated by condensate steam turbines are also significantly minimum compare to other forms of energy production. This means condensate steam turbine is an environmentally friendly option. Additionally, these kinds of turbines can be used with different forms of fuels, from natural gas to biomass, allowing them to fit into various energy generation models.

Therefore, condensate steam turbines are too easy to install and easy to use. They are easy to install and require minimal supervision when in operation.

Q. What are drawbacks of using a condensate steam turbine?

Ans. The main drawback of condensate steam turbine is its limited power generation capacity. As compared to other kinds of steam turbines, like ‘back pressure’ and ‘extraction turbines’, the condensate steam turbine generate significantly less power. Cause of this is its design; it does not permit for efficient use of the steam’s energy potential.

In addition, condensate steam turbines need frequent maintenance also servicing, making them more expensive to operate and maintain than other kinds of steam turbines. Finally, condensate steam turbines type has a relatively short lifespan as compared to other kind of turbines, meaning they will require be replacing or upgrading more frequently.

Q. What is surface condenser?

Ans. A surface condenser is a kind of heat exchanger used for condensing vapors, like steam, into liquid form. This process is work by passing the vapor through tubes that are surrounded by a coolant, like water or air. These tubes are typically made of stainless steel (SS) or copper and the coolant can be pumped through the tubes to help decrease the temperature of the vapor. The liquid that is produced from the condensation process is then collected and stored for further use.

Q. What is vacuum in steam turbine?

Ans. Vacuum in a steam turbine is a state of low pressure where the atmospheric pressure is lower than the pressure of the steam. It is important for the steam turbine to maintain a vacuum in order to maximize the efficiency of the turbine and to increase the amount of power that can be generated. Vacuum is typically produced by a condenser and a vacuum pump, which both work together to cool and condense the steam, creating a negative pressure that pulls the steam through the turbine blades.

Q. How vacuum created in steam turbine ejector?

Ans. Vacuum is created in a steam turbine ejector by using the kinetic energy of the steam to draw in outside air and exhaust it away from the turbine at a much lower pressure. The steam jet is directed towards the exhaust opening, which creates a low-pressure area at the inlet. This causes the lower-pressure air to be drawn in and mixed with the steam, lowering the pressure further and creating a vacuum. This vacuum is then used to power the turbine, allowing it to function more efficiently.

Q. How vacuum break in steam turbine ejector?

Ans. Vacuum break in a steam turbine ejector is achieved by introducing a controlled amount of additional steam into the suction side of the ejector. This additional steam helps to reduce the negative pressure, or vacuum, which can cause the ejector to become unstable. The amount of additional steam needed is determined by the size of the ejector, the load being operated, and the type of turbine being used. To ensure safe and efficient operation, it is important to adjust the steam flow rate to meet the demands of the system.

Q. What is gear box in steam turbine?

Ans. A gear box in a steam turbine is a set of gears that are used to increase the speed of the turbine’s rotation. These gears are used to rotate the turbine more quickly, allowing it to generate more power. The gear box is typically made up of several different gear sets, each of which has a unique set of teeth that can be used to precisely control the speed of the rotation.

Q. How condensate steam turbine started?

Ans. A steam turbine is started by introducing steam into the turbine at a controlled rate. The steam flow is gradually increased to the desired level. As the steam flow increases, the turbine wheel begins to spin and accelerates as the steam flow increases. The speed of the turbine is controlled by regulating the steam flow into the turbine.

Q. How barring started in condensate steam turbine?

Ans. Barring in condensate steam turbines typically occurs when the turbine rotor is forced to rotate by an external mechanical device. This is done to ensure that the rotor is properly balanced and that the turbine runs smoothly and efficiently. The rotor is then forced to rotate at a predetermined speed, which is typically very slow. This process is known as barring and is used to check the turbine for any mechanical or electrical faults. Barring can also be used to check for any cavitations or other irregularities in the turbine blades.

Q. What is lube oil system in condensate steam turbine?

Ans. The lube oil system in a condensate steam turbine is a system that provides the lubrication necessary for the turbine components to run smoothly and efficiently. The system consists of an oil pump, an oil filter, a reservoir, and a piping system. The oil pump is responsible for supplying the lube oil to the turbine components, while the filter removes any impurities from the oil. The reservoir stores the lube oil, and the piping system ensures that the oil is delivered to all the necessary components. The lube oil system is essential for the proper functioning of the condensate steam turbine.

Q. How to calculate steam turbine efficiency?

Ans. Calculating steam turbine efficiency is a relatively straightforward process. First, you need to determine the turbine’s inlet steam conditions, including its pressure, temperature, and mass flow rate. Then, you need to determine the turbine’s exhaust steam conditions. From these two sets of data, you can calculate the turbine’s isentropic efficiency, which is an indication of the turbine’s overall efficiency.

You can use the following equation to calculate the isentropic efficiency:

Isentropic Efficiency = (Actual Output/Isentropic Output)*100%.

Once you have the isentropic efficiency, you can calculate the turbine’s overall efficiency by factoring in other losses such as mechanical, thermal, and radiation losses.

With all this data, you should be able to calculate the steam turbines efficiency.

Q. How condensate extraction pump works?

Ans. A condensate extraction pump is a device that is used to remove condensate from a boiler, air conditioner, or other system. It works by using a centrifugal force to separate the condensate from the system’s vapor. The condensate is then collected in a separate container, usually a reservoir or tank. The pump then circulates the condensate through a pipe to a drain or other outlet. The extraction pump is typically powered by a motor, and its speed can be adjusted to match the flow rate of condensate being extracted. The pump should be regularly maintained to ensure it is working properly and safely.

Q. How vacuum increase in ejector of steam turbine?

Ans. Vacuum increase in the ejector of a steam turbine is achieved by increasing the temperature difference between the steam and the condensate. This is done by increasing the steam temperature, decreasing the condensate temperature, or both. The increased temperature difference causes the steam to be more energetic, creating a stronger vacuum in the ejector. Additionally, increasing the speed of the steam flow can also increase the vacuum created in the ejector.

Q. What will happen with hot well label when vacuum drops suddenly?

Ans. Hot well label increased suddenly.

Q. Why the vacuum in a steam condenser which is located at higher elevation is lower than that of located at lower elevation?

Ans. Because at a high elevation, atmospheric pressure goes on decreasing. So maximum main tenable vacuum will be less.

Q. What is the quantity required of lube oil for generator?

Ans. It is 8 to 10% of total lube oil flow

Q. What is the temperature difference should be between turbine exhaust temperature and condensate steam in hot well?

Ans. Actually if there is no leakage is in the system, both the temperature should be same. However 2 to 3 degrees centigrade difference is allowed.


Frequently Asked Questions

Q. What is meant by no load operation of steam turbine?

Ans. A turbine called as no load if enough steam is flowing into steam turbine for covering mechanical losses and maintain rated speed.

Q. How do you measure the steam turbine casing expansion?

Ans. Generally, it is measured with the equipment of LVDT (linear variable displacement transducer).

Q. What is vacuum?

Ans. vacuum means any pressure below atmospheric pressure.

Q. What is the full meaning of MOP?

Ans. Main Oil Pump

Q. What is the full meaning of AOP?

Ans. Auxiliary Oil Pump

Q. What is the full meaning of EOP?

Ans. Emergency Oil Pump

Q. What clearance should be between rotor and casing diaphragm?

Ans. It is 0.6 to 1.5 mm

Hey, provided ‘Steam Turbine Questions and Answers‘ play important role if you prepare for any kind of power plant job.

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