Power station 23

 Question = A power station has to meet the following load demand: 


(1) Diversity factor (2) unit generated per day (3) Load factor . 

Solution = the given load cycle can be tabulated as under : 


From this  table it's clear that total load on power station is 20 kW for 0 to 10 hours , 50 kW for 10 to 4 pm hours , 70 kW for 4 pm to 6 pm hours , 50 kW for 6 pm to 10 pm hours and 20 kW for 10 pm to 12 pm , hours . 


Plotting the load on power station versus time , it is clear from the curve that maximum demand on the station is 70 kW and occurs from 4 pm to 6 pm . 

(1) Diversity factor = sum of individual maximum demand of groups ÷ M.D , 

» where , sum of individual maximum demand of groups = 50 + 30 + 20 = 100 kW ,

» maximum demand show in figure = 70 kW , 

» D.F. = 100 ÷ 70 = 1.42 answer ✓ 

(2) unit generated per day = kW × hours ,= [ ( 20 × 10 ) + ( 50 × 6 ) + ( 70 × 2 ) + ( 50 × 4 ) + ( 20 × 2 ) ,= 880 kWh , answer ✓ 

(3) » Load factor = average load ÷ maximum demand , 

» Average load = unit generated per day ÷ 24 h = 880 kWh ÷ 24 h = 36.666 kW , 

» So , L.F.= 36.666 kW ÷ 70 kW = 0.5238 , 

» for % ( × 100 ) = 0.5238 × 100 = 52.38 % , answer ✓ 

Comments

Post a Comment

Popular posts from this blog

Polyphase circuit part 6

Image
  Question = एक balanced load , 3 phase , star connected , resistance load में प्रति phase 1000 Ω का resistance लगा हुआ है। जो कि 230 volt/ phase 50c/s supply के साथ जुड़ा हुआ है। लाइन current , cos Ø और power factor मालूम करें ? Solution = is given.  R = 1000 Ω , V L  = 230 v/pH.. , f = 50 c/s , Formula = I L  = V L  ÷ R » 230 ÷ 1000 , » 0.23 ampere , answer ✓ » W= V×I » 230 × 0.23 » 52.9 watt, तो wattage in 3 phase = 3 × 52.9 =  158.7 watt , answer ✓  » Cos Ø = Input ÷ √3 × V L  × I L  ,  » 158.7÷ 1.732 × 230 × 0.23 , » 1.72 या 1(unity ) (क्योंकि power factor 1 से अधिक नहीं होता है)            (Circuit में resistance load हैं इसलिए PF unity होगा।) Answer ✓
Read more

Electrical bill निकालना,

  Question = किसी electrical circuit में 15 lights point प्रत्येक 60 watt, 8 light point प्रत्येक 40 watt , 6 fan प्रत्येक 40 watt और एक pump 1/2 HP का हैं।light और fan का 50% load प्रतिदिन 4 hours और pump प्रतिदिन 3 hours काम करता है। 33paisa/kWh unit की दर से एक महीने के लिए बिल बनाओ?  Solution = (1) 15 light point प्रत्येक 60w= 15×60= 900 watt,  (2) 8 light point प्रत्येक 40w = 8×40=320 watt, (3) 6 fan point प्रत्येक 40= 6×40= 240 watt,  (4) 1/2 hp का pump =746/2 = 373 watt, Lights और fan का Total watt =900+320+240= 1460 Watt,  Lights और fan का 50% load=1460×50÷100;  730 watt,       so, watthour= 730×4= 2920 wh, pump का watt hours =373×3= 1119 watt hours,   Total kWh= 2920+1119     = 4039                                                   1000                1000 =4.039 kWh;        = 30 दिन के kwh = 30×4.039,. =121.17 kWh,  खर्च = 121.17×33 = 3998.61 Paisa या 39.98 ₹, answer ✓
Read more

Specific resistance की calculation

Image
  Question = एक 9.15 meter लंबी copper की bus-bar का resistance 0.000168Ω हैं। यदि इसका कटाक्ष क्षेत्रफल 7.62×1.27 cm² हो तो copper का specific resistance मालूम करें ? Solution= Length=9.15 meter, R=0.000168Ω, Area= 7.62×1.27cm²,  = spe... Resis... (rho) ? ,  Formula, Rho= R×A/L, =0.000168×7.62×1.27/9.15 Ω cm, (9.15meter ×100=915cm), और (μ=10⁶) =168×762×127×100/915×10⁶×100×100×100;  =1016127/ 571875×10⁶;  =1.77/10⁶;  = 1.77 μΩ cm,  answer ✓ Question =एक copper की wire का specific resistance (rho)1.79 μΩ cm हैं, यदि इसका व्यास या diameter 0.091 cm हैं और length 3.66 cm हैं। इसका resistance मालूम करें? Solution = rho=1.79 μΩ cm, dia= 0.091 cm, l=3.66 cm, R=?  Formula =R= ρL/A, =A=πd²/4; (π=3.14)  =A=3.14×0.091²/4;   =314×91×91/4×100×1000×1000, =2600234/4×10⁸ ; =650058.5/10⁸ ; =0.00650085 cm²,  इसलिए, R= 1.79×3.66/10⁶ ×0.0065;   =179×366×10000÷10⁶ ×65×100×100;  =1007.9÷10⁶: =0.001 Ω, answer ✓
Read more