A superheater is a vital part of the a boiler system that is used to increase the overall efficiency of a thermal power plant . More specifically, it is a device which converts wet steam (saturated steam) into dry steam as dry steam contains more thermal energy.
What is the function of super heater in the boiler?
In a steam engine, the superheater re- heats the steam generated by the boiler, increasing its thermal energy and decreasing the likelihood that it will condense inside the engine . Superheaters increase the thermal efficiency of the steam engine, and have been widely adopted.
What is the function of super heater and economizer?
Since the super heater steam has a lot of energy the super heater is used for reduce the temperature of the steam, the economizer helps in minimizing the conservation of energy and re-heater is used for increasing the thermal efficiency of the boilers.
What is the function of superheater in the boiler Mcq?
Explanation: Function of the superheater is to increase the temperature of steam above its saturation temperature .
What is economiser function?
Economizers (US and Oxford spelling), or economisers (UK), are mechanical devices intended to reduce energy consumption, or to perform useful function such as preheating a fluid . The term economizer is used for other purposes as well.
What is the difference between boiler and super heater?
It is different from a boiler in a way that, boiler utilizes both sensible heat as well as latent heat to convert water into steam while superheater utilizes only sensible heat to superheat the steam in order to increase its enthalpy.
What is the advantage of super heater steam?
| Property Disadvantage | Low heat transfer coefficient Larger heat transfer surface area needed | Variable steam temperature even at constant pressure Superheated steam needs to maintain a high velocity, otherwise the temperature will drop as heat is lost from the system |
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Which boiler is best for fluctuating demand of steam?
| A. Lancashire boiler is a fire tube boiler. | C. Babcock and Wilcox boiler is a water tube boiler. | D. all of the above |
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What is the pH value of water permissible for boiler?
Boiler pH. Natural water is usually between 6.5 and 7.5 pH. A common recommendation is to maintain boiler water at 8.5 pH .
What is the function of economizer in boiler?
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. There are 2 types of economizers: non-condensing and condensing.
What is boiler flue gas?
Flue gas refers to a chemical byproduct substance that is generated as a result of a combustion reaction that has escaped through long pipes such as those in boilers, furnaces or steam generators. Flue gas may also be referred to as exhaust gas and may act as a reactor agent for atmospheric corrosion.
What is the major disadvantage of the Benson boilers?
Explanation: The major disadvantage of the Benson boiler is that when water transforms into steam in the convective section of the evaporator, salts are deposited in the transformation zone .
What is the pH value of water permissible for boiler *?
What is the pH value of water permissible for boiler? Explanation: The pH value of water used in the boiler is slightly greater than 7 for most of the commonly used boiler.
What is a Rankine cycle process?
The Rankine cycle or Rankine Vapor Cycle is the process widely used by power plants such as coal-fired power plants or nuclear reactors. In this mechanism, a fuel is used to produce heat within a boiler , converting water into steam which then expands through a turbine producing useful work.
What is priming in boilers?
Priming is the process by which contamination in water droplets leave the boiler with the steam during heating. Priming can either be caused by mechanical factors such as: Construction of the boiler. High water level. Operating the industrial boiler steam pressure below its designed level or.
What is the function of steam drum?
Unsourced material may be challenged and removed. A steam drum is a standard feature of a water-tube boiler. It is a reservoir of water/steam at the top end of the water tubes. The drum stores the steam generated in the water tubes and acts as a phase-separator for the steam/water mixture .
At what temperature is steam superheated?
superheated steam, water vapour at a temperature higher than the boiling point of water at a particular pressure. For example, at normal atmospheric pressure, superheated steam has a temperature above 100 °C (212 °F) .
What is the difference between high and low pressure steam?
Difference between low-pressure vs.
High-pressure steam is essentially squeezed more tightly. So, to transfer the same load, the steam doesn’t have to move as quickly through the pipes. ... Low-pressure steam is limited to 15 PSI (pounds per square inch). High-pressure steam applications require more than 15 PSI.
What is dryness factor?
Dryness fraction is defined as the ratio of mass of dry steam (vapour) to combined mass of dry steam (vapour) & mass of liquid in mixture . It is denoted by x.
What is degree of superheat?
The Degree of Superheat can be defined as the amount by which the temperature of a superheated vapor/steam exceeds the temperature of the saturated vapor/steam at the same pressure .
What type of boiler is a lemon boiler?
A LaMont boiler is a type of forced circulation water-tube boiler in which the boiler water is circulated through an external pump through long closely spaced tubes of small diameter. The mechanical pump is employed in order to have an adequate and positive circulation in steam and hot water boilers.
Which boiler is most successful boiler in the gas turbine industries?
This boiler can increase the heat transfer or can say steam generation rate without increasing boiler size. This is why; Velox boiler is most successful boiler in the gas turbine industries.
Which of the following boiler steam is critical boiler?
A supercritical steam generator is a type of boiler that operates at supercritical pressure, frequently used in the production of electric power. In contrast to a subcritical boiler in which bubbles can form, a supercritical steam generator operates at pressures above the critical pressure – 22 megapascals (3,200 psi).
What is TDS in boiler water?
Total Dissolved Solids (TDS) are the impurities in boiler feed water that reduces the heat transfer rates, increase scale deposits, increase heat losses thereby reducing the boiler efficiency. ... Substances that are dissolved in water and cannot be seen by naked eye are called dissolved solids.
What chemicals are used in boilers?
The most common alkaline solutions for boiler water include sodium hydroxide and potassium hydroxide . You can typically purchase these products with a 25 percent concentration or a 50 percent concentration.
Which type of water is used in boiler?
The boiler receives the feed water, which consists of varying proportion of recovered condensed water (return water) and fresh water , which has been purified in varying degrees (make up water). The make-up water is usually natural water either in its raw state, or treated by some process before use.
What is the efficiency of chimney?
Efficiency of chimney draught is of the order of. 8-10%
What is the pH of steam?
It comes into play with steam boilers because a pH between 7 and 9 (slightly alkaline) is just right. If the pH is lower than that, the water will start eating the pipes. If it’s higher than that, the water won’t corrode metal, but it may begin to foam, and that’s not good. Hold that thought for a moment.
Which boiler tubes is surrounded by hot gases?
Explanation: A water tube boiler is a boiler in which the cool water containing water tubes are surrounded by hot gases.
What is evaporator in boiler?
Evaporator is a boiler component that functions to convert water into saturated steam . It is able to change the whole or part of a solvent from a solution in the form of liquid to steam. So that it only leaves a denser or thick solution. The process that occurs in the evaporator is called evaporation.
In what form is the coal used in boiler?
Explanation: The coal used for boiler is in powder form, in order to increase thermal efficiency. The different types of coal used in boiler are generally bituminous coal , brown coal and peat. Commonly bituminous coal is most preferred boiler fuel since it has volatile matter from 8 to 33% and ash content of 5 to 16 %.
What is purpose of boiler?
The function of a boiler is to either produce hot water or steam . Hot water boilers heat water for the purpose of domestic or commercial heating and hot water supply. Steam boilers generate steam in order to power turbines for power generation and various other industrial heating applications.
Do boilers produce carbon dioxide?
Boilers can produce carbon monoxide naturally , but the gas is usually carried out of your house via a flue. If your flue is blocked, the carbon monoxide has nowhere to go and will escape into your home. Carbon monoxide can also be present as a result of a leak in your appliance.
Is boiler flue gas harmful?
Boiler flues are a crucial part of your heating system. ... If your boiler isn’t burning the gas correctly, carbon monoxide could be produced too. Boilers are made to be safe, and these gases shouldn’t harm you . However, a blocked flue can mean the gases become trapped in your home, causing you to breathe them in.
What is the temperature of flue gas?
The typical furnace outlet temperature of flue gases is usually around 1200 °C which will decreases gradually along the pathway of heat transfer, while the temperature of the flue gases going to stack is around 150 °C.
What is the capacity of Benson boiler?
Capacity: The capacity of the Benson boiler is about 150 tonnes/hr at a pressure of 210 (kg force per square centimeter). and at a temperature of 650oC.
What is the major advantage of the Benson boiler?
Advantages of Benson Boiler
The cost of the boiler is low because there is no water and steam drum . There is no pressure limit, therefore supercritical pressure may be used. The high pressure avoids the bubble formation in the tubes which increases the heat transfer rate. It is a lightweight boiler.
What type of boiler is a Benson boiler?
Benson Boiler is a water tube boiler . This is a drum-less and high-pressure boiler.
What is Rankine used for?
The Rankine scale (essentially an absolute version of the Fahrenheit scale) and the Kelvin scale (an absolute version of the Celsius scale) are rarely used by anyone for measuring temperature. They are used for calculations in physics, chemistry and engineering related to them .
What is Rankine cycle used for?
Rankine cycle, in heat engines, ideal cyclical sequence of changes of pressure and temperature of a fluid, such as water, used in an engine, such as a steam engine. It is used as a thermodynamic standard for rating the performance of steam power plants .
What is the difference between Carnot and Rankine cycle?
Carnot cycle is a theoretical cycle whereas the Rankine cycle is a practical one. Carnot cycle ensures the maximum efficiency under ideal conditions, but the Rankine cycle ensures the operation in real conditions. The efficiency obtained by the Rankine cycle is always lower than that of the Carnot cycle .
