How to Calculate Boiler Efficiency

 

Calculation formula :

This method calculates boiler efficiency by using the basic efficiency formula-

η=(Energy output)/(Energy input) X 100

In order to calculate boiler efficiency by this method, we divide the total energy output of a boiler by total energy input given to the boiler, multiplied by hundred.

Calculation of direct efficiency-

E= [Q (Hg-hf)/q*GCV]*100

Where,

Q= Quantity of steam generated (kg/hr)

Hg= Enthalpy of steam (Kcal/kg)

hf= Enthalpy of water (kcal/kg)

q= Quantity of fuel

GCV= Gross calorific value of the fuel

Enthalpy : Heat Content of system at constant pressure

                  H : U + PV 

U : Internal Energy ( E) ,  P : External Pressure , V : Volume 

GCV : The amount of heat energy produced on complete combustion of 1 kg of fuel

Example : 1

Total Steam Generate : 30000 kg

Total fuel Consumption : 2000 ltr ( HSD ) High Speed Diesel

E= [Q (Hg-hf)/q*GCV]*100                        

Q : 30000 kg            Steam Pressure : 8 kg/cm2

q  :  2000 ltr             Feed Water Temperature : 60 degree

1> Enthalpy of steam on 8 kg/cm2 : 661 Kcal/Kg

2> Enthalpy of Water at 60 degree :  60 Kcal/ kg

3> GCV Value of fuel ( HSD )            :   10800 Kcal/kg

Step : 1  Hg : 661 , hf : 60     > 661-60 = 601

   =  (30000( 661-60)/ 2000 x  10800)X100

  =   ( 30000( 601)/21600000) x 100

  =   (18030000/ 21600000) X 100

  =    83.4 %

Example : 2

Total Steam Generate : 30000 kg

Total fuel Consumption : 3500 kg Coal

E= [Q (Hg-hf)/q*GCV]*100                        

Q : 30000 kg            Steam Pressure : 8 kg/cm2

q  :  3500 kg           Feed Water Temperature : 60 degree

1> Enthalpy of steam on 8 kg/cm2 : 661 Kcal/Kg

2> Enthalpy of Water at 60 degree :  60 Kcal/ kg

3> GCV Value of fuel ( coal )            :   5800 Kcal/kg

Step : 1  Hg : 661 , hf : 60     > 661-60 = 601

   =  (30000( 661-60)/ 3500 x  5800)X100

  =   ( 30000( 601)/20300000) x 100

  =   (18030000/ 20300000) X 100

  =    88.81 % 

                                                Steam Enthalpy Chart 

                                                                 Enthalpy of Water Chart on Temperature based

 

GCV Value of fuel  

HSD : Gross calorific value of Diesel or HSD is 10800 Kcal/kg

Coal :  Gross calorific value coal is  5800 Kcal/kg  

also watch  full video 📺

What is Steam Traps and Types

 Steam Traps : 

A steam trap is an mechanical device  that holds the steam and  allow the condenses to flow out .

Types of Steam Traps : 

1. Thermodynamic Steam Trap Valve
2. Thermostatic Steam Trap Valve
3. Float Steam Trap Valve
4. Inverted Bucket Steam Trap Valve

 Why Steam Traps Used : 

We know that Steam generate from water at a particular temperature . When steam flow in pipes its temperature decrease and start to convert in water again or when heating a vessel steam convert into condensate or water .   

Property of Steam : 

Steam is an invisible gas created by adding heat energy to water. It is liquid water changed to its gaseous state at particular pressure and temperature or easily convert again in water when temp decrease .

What is Steam Condensate : When the temperature of steam decrease than steam start to convert in water molecules .  

Design of Trap Valve  

 Parts of Steam Trap Valve : 

1. Insulation Cap 

2. Cover 

3. Disc

4. Body 

5. Strainer 

6. Strainer Plug 

7. Blow down valve (optional ) 

Working of Steam Trap Valve : 

At star-up, air will enter the steam trap and will be discharged out through the bleed hole. 2. As condensate enters the trap, it forms a water seal inside the body. The weight of the bucket keeps the valve off its seat and so condensate can flow around the bottom of the bucket and out of the trap

Watch full Video on Working of Steam Trap Valve :

What is Steam Trap and Working 📺

How to calculate Steam Load and Steam Consumption

 Steam Load Calculation 

            In general steam heating is used to

•       change a product or fluid temperature

•       maintain a product or fluid temperature

                                               

                                                 Formula for Steam Consumption in Heating Vessel 

                                                               Q = m c△ t

•       Q =  Quantity of heat or  energy ( unit : kj )

•       m =  mass of liquid ( Unit : kg or Litre )

•       c= Specific heat ( Unit : kj/kg )

•       △ t = change in temp

 Example : 

     5000 kg water heat from temp 20 to 80 degree at 3 kg steam pressure . Calculate steam consumption . 

•       Use formula Q = m c △ t

 •       m        = 5000 kg

•       C    = 4.19 kj/kg  ( Standard )

•       △ t    = ( 80-20) = 60 degree

 •       C ( Specific heat) : quantity of heat required to raise the temperature of one gram of a substance by one Celsius degree

 •       m        = 5000 kg

•       C   = 4.19 kj/kg  ( Standard )

•       △ t    = ( 80-20) = 60 degree

•       Q = 5000 X 4.19x 60

•           = 1257000 kj

 •       Convert kj to kg

•       Divide by Latent heat of steam

 •       Amount of  heat required to convert 1 kg of liquid to vapour or steam  

 •       Latent heat of steam at 3 kg is 2163.22

        Q = 5000 X 4.19x 60

           = 1257000 kj

       Latent Heat of Steam = 2163.22  kj/kg

      = 1257000/2163.22

       =  581.07 kg 

                     

 Thanks 

Watch full video on Steam consumption calculation

 

What is Formation of steam

 Formation of steam : Changing of state ( liquid to gaseous ) 

How to generate Steam : 

steam that occurs when the liquid and gaseous phases of water exist simultaneously at a given temperature and pressure. In simpler terms, the steam is in equilibrium with the heated water. During the saturated condition, the rate at which water is vaporized is equal to the rate at which it is condensed.

When heat is applied to water, its temperature continues to rise until it reaches its boiling point at that pressure. As further heat is added, the water vaporizes and converts to steam. The steam that exists at the same temperature as the water from which it is formed is known as saturated steam. In other words, saturated steam exists at approximately 100°C (212°F) at atmospheric pressure.

Formation Process Chart :  

                   

Formation Start from point 

  1> A to B 

Point A consider Ice temp approximate -15 degree, when heat added to ice and it temp increase -15 degree to 0 degree at a particular of time  but still Ice not melt because of its freezing point of ICE . Heat apply during this process is  A-B is called sensible heat of ice .

Sensible Heat : when heat apply only temp increasing and decreasing but no changing in face is called sensible of heat .

     2 > B to C

After point B if more  heat apply to ice it start melting  at constant temp. till whole ice melted and convert into water .  This heat is called  latent heat of fusion of ice  .

Latent  Heat : During  heat apply temp remain constant at a particular of time and there is change of face is called Latent Heat .

Heat Apply A to B & B to C  is called total heat of Water .

3> C to D

  Further addition of heat at point C , it increase the temp of water 0  to 100 º C know as the boiling temp of water .  This process C – D is know as sensible  heat of water .

   3> D to E’ and E’ to E  & E to F

                                           

Further heat apply beyond point D , heat utilized for water of vaporization and state changing liquid to vapour without change in temp or constant temp. The amount of heat added during this process is called latent heat of vaporization .  The wet steam contain some water particles in suspended foam , it represented E’ in TH diagram or heat apply beyond the point E’ carries sufficient amount of heat energy to convert all the water in gaseous state  is know as dry saturated steam , it represented point E in TH diagram . Now superheated steam obtained by heating dry saturated steam at constant pressure , it represented by E-F and amount of heat apply during is process is called heat of superheat. 

This is the total process of formation of steam ( Ice to Superheated steam ) 

 Also watch on you tube 

https://youtu.be/bmwCRC9V3co

Also Watch full video on you tube :   Formulation of Steam 📺

What is Steam and its types and properties ( https://youtu.be/DQPGfG_kJuM )

 Steam : When we provide continuous heat to water then at 100 temperature and 1 atm pressure, it boils and changes its phase from liquid to vapors. This vapors is known as steam .

Types of Steam : https://youtu.be/DQPGfG_kJuM

1. Wet Steam 

2.  Saturated Steam

3. Superheated Steam .

1. Wet Steam : When steam contains water particles is know as wet steam .

2. Saturated Steam  :  When wet steam further heated then all water particle get converted into vapour and resulted steam is called Saturated Steam .

3. Superheated Steam : When   Saturated Steam is heated to higher temperature then steam obtained is in superheated state . This type of steam mostly use in power generation 

When dry saturated steam is heated to higher temperatures then steam obtained is in superheated state. This steam is mostly used in Power generation.

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