Interview Questions.

Question 1. What Are The Main Circuits In The Thermal Power Plant?

Answer :

Thermal Power plant includes four fundamental circuits, they're:

Feed water and steam waft circuit.
Coal and ash circuit.
Air and gas circuit.
Cooling water circuit.
Question 2. Steam Power Plant Works On Which Cycle?

Answer :

Steam strength plant works at the precept of Rankine Cycle.

Electronics and Communications Engineering Interview Questions
Question 3. What Is The Thermal Efficiency Of Steam Power Plant?

Answer :

Thermal efficiency of steam power plant is described as the ratio of warmth equivalent of mechanical power transmitted to the turbine shaft to the warmth of combustion. Generally Thermal performance of the steam strength plant could be inside the variety of 30-35%.

Question 4. What Is The Overall Efficiency Of The Thermal Power Plant Or Steam Power Plant?

Answer :

Overall efficiency of the machine is described as the ratio of warmth equivalent of electrical output to the heat of combustion. Generally Overall efficiency of the steam plant will usually be less than the thermal efficiency of the steam plant, it will be of the order of 29-33%.

Overall efficiency of steam plant is determined by way of multiplying the thermal performance of the plant with performance of the generator (electric performance).

Power Electronics Tutorial
Question five. Why The Thermal Efficiency Of The Steam Power Plant Is Quite Low?

Answer :

In Steam electricity station, greater than 50% of the entire warmth of combustion is lost as warmth rejected to the condenser and the loss is unavoidable as the heat strength cannot be converted in to mechanical power with out a drop in temperature. Steam in the condenser is at lowest temperature. This is the cause that the thermal performance of the strength plant is quite low.

Operations Management Interview Questions
Question 6. On What Factors Efficiency (thermal) Of The Steam Plant Depends?

Answer :

Efficiency of the thermal plant relies upon on three elements, they may be

strain of steam coming into the turbine
temperature of the steam entering the turbine
pressure in the condenser
Thermal efficiency will increase with boom in temperature and pressure of the steam getting into the turbine. For this cause excessive temperature and pressure are used. Thermal efficiency is successfully extended via decreasing the strain in the condenser, so stress inside the condenser is stored as little as possible.

Thermal performance also increases through reheating the steam between turbine tiers.

Question 7. Why Efficiency In Thermal Power Plant Is Low?

Answer :

Almost 50% of the warmth generated is misplaced at the condenser as warmness rejection. It is unavoidable as without heat rejection it is not viable to convert warmth electricity into mechanical strength and force the turbine without drop in temperature. Therefore majority of the loss takes place within the condenser. Thus performance of the thermal electricity plant is among 30-35%.

Renewable Energy Tutorial Electrical Engineering Interview Questions
Question eight. On What Cycle Does Thermal Power Plant Operate?

Answer :

Thermal Power plant works on the principle of Rankine cycle.

Question nine. Why Generation Voltage In Thermal Power Plant Is Between 11kv To 33kv?

Answer :

The cutting-edge carrying conductor move segment depends upon the significance of the contemporary it is carrying and insulation energy of the conductor depends at the maximum voltage it is able to withstand. Therefore whilst designing the generator an most beneficial value is selected among the quantity of the modern-day and voltage conductor can resist.

Power Electronics Interview Questions
Question 10. How Efficiency Of Thermal Plant Can Be Improved?

Answer :

Some of the techniques through which the performance of the thermal plant may be stepped forward are:

By increasing the temperature and strain of the steam coming into the turbine.
By lowering the strain within the condenser.
By reheating the steam between unique stages among the turbine.
Question eleven. Advantages And Disadvantages Of Thermal Power Plant?

Answer :

Advantages:

Thermal Power Plants can be operated near the load facilities not like hydro and nuclear plants.
Requires less space in comparison to hydro vegetation and value of construction is much less.
Running or working prices are much less in comparison to diesel or gasoline vegetation.
Can able to take care of over load for positive time frame.
Disadvantages:

Emits inexperienced house gases and reasons pollution.
Coal and Ash coping with calls for large region.
Efficiency is low.
Power Plant Project Interview Questions
Question 12. What Is Cavitation And Disadvantages Of Cavitation?

Answer :

The formation of air bubbles and water vapour on the water floor due to the discount in the strain is referred to as "Cavitation". When the pressure at the water reduces under the saturation stress similar to the temperature of the water, the rapid formation of the water vapour and air bubbles starts. The bubbles  disintegrate with the violent action and this collapsing stress may be very high. The fast formation and collapsing of bubbles reasons the pitting of the steel floor. Cavitation additionally reduces the performance of the hydraulic high mover causing the honey-combing of runner and blade contours which reduces the power output.

Electronics and Communications Engineering Interview Questions
Question 13. What Is The Largest Pump In The Thermal Power Plant?

Answer :

In thermal energy plant Boiler Feed Pump (BFP) is the biggest pump, it offers the water to the boiler.

Question 14. What Are Different Types Of Steam Boilers Used In Thermal Power Plants?

Answer :

Different sort of boiler utilized in thermal energy plants are:

Fire tube boiler
Water tube boiler
Natural Circulation boiler
Forced Circulation boiler
Once via boiler
Question 15. What Are Different Types Of Pulverizes?

Answer :

Different varieties of Pulverizers are:

Ball tube mill.
Ring roll mill.
Hammer mill.
Attrition kind mill.
Steam Turbine Interview Questions
Question 16. What Is The Purpose Of Pulverizes?

Answer :

Pulverizers serve  functions, to dry the coal and to grind the coal. They crush the coal to size of 74microns.

Question 17. What Are The Different Auxiliary Systems In Thermal Power Plant?

Answer :

Coal handling and storage, coal pulverizes  water remedy plant, steam boiler, Drought structures, Ash Handling systems, Steam turbine, Circulation water gadget, Electrical Systems, Control and Instrumentation, Pollution Control system, and Fire Protection System.

Nuclear Power Plant Interview Questions
Question 18. What Type Of Cooling Is Provided For Generator In Power Plant?

Answer :

Hydrogen gas cooling is employed for massive size generators due to higher warmth wearing potential of the hydrogen. Hydrogen cooling is supplied for rotors and center of the generator. Water cooling is furnished for the stator of the alternator.

Operations Management Interview Questions
Question 19. What Are Different Types Of Circuit Breakers Employed In Thermal Power Plant?

Answer :

For low voltage operation 415/220V vacuum circuit breakers or air destroy circuit breakers are hired. For voltage scores about 6.6kV and beyond SF6 circuit breakers are hired.

Question 20. How Generator Transformer Is Cooled In Thermal Power Plant?

Answer :

MVA electricity rating of the Generator Transformer might be equal to the alternator. Hence lot of heat could be generated even as generator transformer is under operation. Oil Forced Air Forced (OFAF) kind of cooling is hired for generator transformer.

Renewable Energy Interview Questions
Question 21. What Are The Different Generator Protections Employed In Thermal Power Plants?

Answer :

Faults in the windings, Over load protection, Over heating of windings or bearings, Over speed protection, Loss of Excitation protection, Motoring operation protection, Inadvertent energisation, single phase or unbalanced current protection, out of step operation protection, sub-synchronous oscillations protection and earth fault safety.

Question 22. What Are The Major Electric Systems In Thermal Power Plant?

Answer :

Major electric device in thermal power plant are

Turbine Generator.
Exciter System.
Generator Protection System.
Generator Transformer.
HT/LT transfer tools.
Electrical Switch-yard.
Question 23. What Is The Difference Between Safety Valve And Pressure Relief Valve?

Answer :

Difference between protection valve and alleviation valve

Relief Valve: The  comfort valve is used on a filled vessel. For one of these valve the opening is proportional to growth within the vessel pressure. Hence the outlet of valve isn't unexpected, however slow if the stress is improved progressively. A remedy valve is supposed to relieve pressure to save you an over pressure situation.  A relief valve can also have an operator on it to help in starting the valve in response to a manage signal. The capability of PRV are normally small.

Safety Valve: This tool is used to  alleviation on a compressible stuffed vessel. For such a valve the hole is surprising. When the set stress of the valve is reached, the valve opens nearly completely. A safety valve is meant to relieve pressure without operator help and a safety valve, or mixture of protection valves, need to be have a capability to alleviate greater than the power input to the quantity being protected.  

Electrical Power System Interview Questions
Question 24. What Is Pressure Relief Valve(prv) ?

Answer :

Image of strain comfort valve.

The remedy valve (PRV) is a kind of valve used to manipulate or limit the stress in a vessel or device for the duration of an overpressure of the system. The primary cause of a pressure Relief Valve is protection of life and property via venting fluid from an over pressurized vessel. Many electronic, pneumatic and hydraulic structures exist today to control fluid gadget variables, inclusive of pressure, temperature and flow. Each of those structures calls for a electricity source of a few type, including strength or compressed air so as to operate.

A stress Relief Valve need to be capable of working at all times, in particular during a duration of energy failure when machine controls are nonfunctional. The PRV is furnished on the on the principle steam line to govern the road stress. The PRV is typically operated via pneumatic pressure.The  PRV operated according to the set strain of rhe controller. The valve set down when the strain attain to everyday value.

Electrical Engineering Interview Questions
Question 25. What Is (nrv) Non Return Valve?

Answer :

This is also called one way valve which allow the fluid drift in a single route best. As its call implies non return way there may be only one route flow.All the meeting are supplied with a valve bonnet.This valves are usually utilized in pump discharges and steam water pipe strains.This device guarantees there's no back glide of fluid from the source. It has  lines one is inlet line and different is outlet line.There is a direction image provided on the valve which display the direction of flow fluid.

Types of NRV:-

Tilting disc test valve-This is a disc type test valve.The disc supplied  fixed with a hinge which swing up and down. As the fluid flow within the line it lift by way of the fluid pressure and allow the fluid to drift inside the pipe. When there is no fluid float in the circuit it closes due to gravitational force.
Ball test valve- Here a round ball is used to fervent the fluid flow. The ball is spring loaded which close the valve while there may be no fluid drift within the line. The pressure of fluid raise the ball and allow the fluid to flow.
Diaphragm type NRV – This is includes a rubber diaphragm clapper ,Which works on the differential  stress When the pressure within the upstream is extra it open the diaphragm and allow the fluid to glide and whilst the stress is equalize is closes diaphragm and prevent to fluid.
Stop check valve- It’s production is identical as the swing take a look at valve except that here's a outside manage mechanism of manage or lever provided.
Lift check valve- Here a boost or disc is supplied which operates at the operating pressure of the fluid.
Question 26. What Is Steam Trap And It's Function?

Answer :

feature of steam trap- It is a tool is used in steam pipe line to discharge condensate and gasses, prevent to break out of steam through the road. It ensures that steam isn't wasted. This is a self contained valve which robotically drains the condensate from a steam containing device. This is commonly supplied in steam drains or earlier than steam drain valve.

Types of steam lure:-

Mechanical entice – Works in the precept of difference in density between steam and condensate. This kind of lure function in accordance the condensate level within the port if the condensate degree growth the glide operates and allow to condensate bypass through the pipe ,when condensate level lower is near the valve and doesn’t permit the condensate. Types of mechanical entice i) Float type, ii)Float with lever type, iii)Inverted bucket kind, iv)Open bucket type.
Thermodynamic type steam lure - Works inside the precept of distinction in between thermodynamic property of steam and condensate.This varieties of traps operate due to pace change in waft of compressible and non compressible fluids.As the steam starts offevolved condensate there may be a temperature distinction which allow the lure to operate. Types of Thermodynamic kind steam lure   i) Disc type ii) orifice type.
Thermostatic kind steam entice-  This trap works in the principle of difference of temperature in between  steam and condensate. Types of Thermostatic kind steam entice i) Bimetallic type, ii) Metallic expansion kind.
Powerbuilder Interview Questions
Question 27. What Are The Methods Are Used For Steam Temperature Control In Boiler?

Answer :

We can control steam temperature by means of :

Using gas recirculation method-Hot flue gasoline is circulated for hold steam temperature.
By imparting extra air- By providing excess air it reduce the furnace temperature for a few timing therefore control temperature.
Burner tilting approach- Here the tilting of burner are supplied by way of a pneumatic cylinder. The burner can be tilted 30° up and down for control temperature.
Attemporation manipulate-This is the nice approach for temperature control in boiler. Here the attemporator  are supplied to spray water in steam in steam pipe line. Ceramic thermal sleeves are  furnished to keep away from thermal shock  due to temperature difference of steam and spray water.
Elevation of gasoline firing – The temperature is managed with the aid of deciding on top or decrease elevation of fuel burner.
Power Electronics Interview Questions
Question 28. What Is The Effect Of Soot Deposits In A Boiler?

Answer :

The deposited soot act as a bad conductor of warmth which reduce the warmth switch charge and increase flue gas temperature.
The deposits block the flue gasoline direction which boom the drought loss.
The deposit might also result in corrosion.
Due to falling of big size of soot it harm the tube in dry ash conveying gadget.
Question 29. What Is Priming Of Boiler ?

Answer :

It Is the sporting amount of droplet water in the steam, witch ends in carryover of Salt crystals on the fantastic heater and mills. Priming can be brought about because of sudden alternate of load and preserving of high level of water.

Prevention of priming and foaming: 

The great remedy for foaming and priming carryover is the right blow down of TDS. The non-stop blow down must   be regulated to hold  the TDS at 3,000 to four,000 ppm. More blow down way much less TDS but extra blow down is the extra lack of the boiler so the blow down should be within manage level.

Wind Turbine Interview Questions
Question 30. What Is Foaming Of Boiler?

Answer :

It is the era of foam In boiler because of high awareness of solids, natural be counted, bubbles are building up at the floor of boiler water and passed out with the steam. This is usually prompted due to excessive attention of solids in boiler.