Determine how much lead taken at a temperature of 0 degrees can be melted during the combustion
| June 2, 2021 | education
Determine how much lead taken at a temperature of 0 degrees can be melted during the combustion of one kilogram of oil if the efficiency of the heater is 80 degrees.
Given: t0 (lead temperature) = 0 ºС; mn (oil mass) = 1 kg; η (heater efficiency) = 80% (0.8).
Constants: q (beats heat of combustion of oil) = 4.4 * 10 ^ 7 J / kg; С (specific heat capacity of lead) = 140 J / (kg * ºС); λ (beats heat of fusion) = 0.25 * 10 ^ 5 J / kg; tmelt (temperature of the beginning of melting) = 327.4 ºС.
The mass of lead is determined from the formula: η = (C * m1 * (tpl – t0) + λ * m1) / (q * m2); m1 = η * q * m2 / (С * (tmelt – t0) + λ).
Calculation: m1 = 0.8 * 4.4 * 10 ^ 7 * 1 / (140 * (327.4 – 0) + 0.25 * 10 ^ 5) ≈ 497 kg.
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