A. improving thermal efficiency
B. cooling
C. collect ash partials
D. all of the above
B. cooling
C. collect ash partials
D. all of the above
Answer: A. improving thermal efficiency
Explanation:
Economizers are heat exchangers that transfer the heat in the flue gas to another medium‚ generally the boiler feed-water‚ although other streams are sometimes used such as make-up water.
An economizer is a mechanical device used to reduce energy consumption.
Economizers recycle energy produced within a system or leverage environmental temperature differences to achieve efficiency improvements.
There are 2 types of economizers: non-condensing and condensing.
Basically, economizer is located in between exit of boiler and entry of air pre heater. When the flue gases are coming out from boiler they take away a lot of heat.
Economizer utilize this heat from flue gases and these heat is used to heat the feed water which is going to feed the boiler.
Economizer is used to absorbing heat from the flue gas for increasing the temperature of the water so that improving the thermal efficiency.
Power System MCQs With Explanation
- The advantages of high transmission voltage are
- The charging current drawn by the cable is
- The fact that current density is higher at the surface when compared to the center is known as
- In which of the following transmission lines capacitance effect is negligible?
- The distribution constant of the transmission line is
- Proximity effect is more in case of
- If the frequency is increased, then the skin effect will
- Bundled conductors in EHV transmission lines help in
- Which of the following produces radio interference in communication lines?
- Telecommunication lines are transposed to reduce the
- What is the function of economizer in Thermal Power Plant
- Which of the following effects are associated with transmission line
- The insulator thickness on the conductor, in cables, depends upon
- By using a guard ring in a transmission line, its string efficiency
- If sag in an overhead line increase, the tension in the line
- Corona is accompanied by
- The conductor carries more current on the surface as compared to the core. This is called as
- Critical disruptive voltage is a voltage at which
- Bundled conductors are used for EHV transmission lines primarily for reducing the
- Low power factor is usually not due to
- Bonding is done at both ends of the cable to reduce the
- For Improving power factor
- Stock bridge dampers are used to
- Which of the following insulator is practically used for railway crossings?
- Which of the following decides the insulation level of 400 kV, EHV line?
- When earth fault occurs
- The minimum length of pipe electrode used for earthing should not be less than
- A ground wire is used to
- Earth resistance in typical domestic wiring is
- By which of the following systems electric power may be transmitted?
- Which of the following equipment will be most economical for regulating the voltage in the distribution feeder?
Transformer MCQs With Explanation
- In a transformer the primary flux is
- The noise of the transformer is mainly due to
- Buchholz relay is used for the protection
- Iron loss in a transformer can be determined by
- Oil is provided in an oil-filled transformer for
- In a star-delta transformer, the delta side phase voltage leads the star sides phase voltage by an angle
- Minimum voltage regulation occurs in transformer when the power factor of the load is
- The chemical used in the breather of a transformer should have the property of
- The power transformer can be termed as a constant
- In a transformer, which of the following losses are zero?
- Which of the following Transformer can have a tap changer?
- If the supply frequency (f) of a transformer decreases, the effect of frequency on the transformer's secondary output voltage?
- The primary winding of a transformer has a 120 V ac supply. What is the value of secondary voltage if the turn ratio is 10?
- The efficiency of a power transformer is _____ at full load.
- In a transformer the relation between the input frequency and the output voltage on secondary winding is _____.
- In a current transformer, _____ winding is closed.
- A transformer is a _____ device.
- A step-down transformer has _____ number of turns on primary winding and _____ number of turns on the secondary winding.
- A step-up transformer has _____ number of turns on primary winding and _____ number of turns on the secondary winding.
- Transformer works on ______ principle.
- Shell Type Transformer is mainly used for
- A Magnetic Oil level Guage (MOG) is used in the Transformer to
- The Function Of Power Transformer is/are
- The Radiators are used in transformers for
Synchronous Motor MCQs With Explanation
- In 3 -Φ synchronous motor if one of the phases is short-circuited the motor will
- The speed regulation of a synchronous motor is
- The negative phase sequence in a three-phase synchronous motor exists when the motor is
- What happens if the field winding of the synchronous motor is short-circuited?
- For power factor correction, synchronous motors operate at