Mixed Fuel Calculation used for Boiler Performance Calculation

We are presenting the checks for Mixed Fuel ratio Calculation & Lab analysis correction to obtain correct Boiler Performance results.

Fuel Mixing Ratio (Weight Ratio OR Heat Ratio) Should be Same in Boiler Performance Test w.r.t. Design Mixing Ratio

EXAMPLE:

  1. In Design Fuel Calculation, Mix Fuel Analysis (Bagasse + Slop) done at Weight Ratio 32.5% & 67.5%
  2. In Performance Test, Mix Fuel Analysis (Bagasse + Slop) done at Weight Ratio 30.5% & 69.5% In-Place of 32.5% & 67.5%
  3. The Difference of Improper Weight Ratio is 2%

FUEL WEIGHT RATIO in BOILER =

Fuel A- Bagasse Quantity -2250 Kg, Fuel B- Slop Quantity -9000 Kg,

Total Fuel Qty = Fuel A + Fuel B = 2250 + 9000 = 11250 Kg

Weight Ratio % in Mixed Fuel for FUEL A- Bagasse = (2250 / 11250) x 100 = 20%

Weight Ratio % in Mixed Fuel for FUEL B- Slop = (9000 / 11250) x 100 = 80%

HOW TO CHECK CORRECTNESS OF MIXED FUEL CALCULATION

1. WEIGHT RATIO CALCULATION for GCV:

Fuel -No. A GCV -100 kcal/kg Ratio in Mix fuel by Weight - 20%

Fuel -No. B GCV -200 kcal/kg Ratio in Mix fuel by Weight - 30%

Fuel -No. C GCV -300 kcal/kg Ratio in Mix fuel by Weight - 50%

Average GCV of above Mixed Fuel for Total 100% = {No.A Ratio (20%) x No.A GCV (100)} + {No.B Ratio (30%) x No.B GCV (200)} + {No.C Ratio (50%) x No.C GCV (300)} = (20/100 x100) + (30/100 x200) + (50/100 x300) = 230 Kcal/kg for Mixed Fuel

2. WEIGHT RATIO CALCULATION for FUEL ANALYSIS:

Average Fuel Analysis of above Mixed Fuel =

Composition% Fuel No.A x 20% Fuel No. B x 30% Fuel No.C x 50% Mixed Fuel %

Carbon 23.5 x 20/100 28.5 x 30/100 33.5 x 50/100 = 4.7 = 8.55 = 16.75 30

Hydrozen 3.25 x 20/100 2.03 x 30/100 2.10 x 50/100 = 0.65 = 0.609 = 1.05 2.309

3. LAB CORRECTION CALCULATION for FUEL ANALYSIS:

Fuel -No. A Lab report Moisture - 45% Design Fuel Moisture - 50%

1. Lab report moisture conversion to Design fuel moisture = (100 - Design fuel moisture) / (100 - Lab report Moisture) = (100-50) / (100-45) = 0.909 i.e. Multiply all Fuel composition by factor 0.909

2. Design fuel moisture conversion to Lab report moisture = (100 - Lab report Moisture) / (100 - Design fuel moisture) = (100-45) / (100-50) = 1.1 i.e. Multiply all Fuel composition by factor 1.1

REPORT CORRECTION @ 45% Moisture Composition% Lab Report - Corrected to Design Design Report - Corrected to Lab

Carbon 26.4 26.4 x 0.909 = 24.00 23.5 23.5 x 1.1 = 25.85

Hydrozen 4.56 4.56 x 0.909 = 4.15 3.15 3.15 x 1.1 = 3.47

Moisture 45 50 50 45

Ash 0.58 0.58x 0.909 = 0.53 1.3 1.3 x 1.1 = 1.43

GCV 2722 2722 x 0.909 = 2474.5 2272 2272 x 1.1 = 2499.2

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