The Efficiency of Heating Using a Flame
The Efficiency of Heating Using a Flame
Thermodynamics II
Contents
Introduction 2
Observations 2
Time/Temperature readings 2
Time/Temperature Plot 3
Calculations and Results 3
1) Enthalpy change of gas burned over the duration of the test 3
2) Heat transfer to the water in the kettle (Qw) 4
3) Heat transfer to the water which evaporates from the kettle (Qev) 4
4) Heat transfer to the kettle from initial to final state (Qk) 4
Find, as a fraction of 1, the values for 2, 3 and 4. 4
5) Air–Fuel Ratio 4
6) Enthalpy of combustion with the water formed by the combustion in the gas phase, (ΔhcoH2Ovap) 5
Using Δhco H2Ovap, find as a fraction of 1), the values for 2), 3) and 4). 6
Discussion and Conclusion 6
Introduction
The purpose of this experiment was to learn about the heat transfer process and determine the energy transferred from a gas flame to the water contained in a stainless steel kettle. The value calculated for the energy transferred is compared with the energy change associated with burning the gas (from calorific values) and the molar enthalpy of combustion of the gas mixture.
Observations
Atmospheric pressure: Pa = (767.15 – 2.49)mmHg = 764.66 mmHg 1 atm = 760 mmHg = 101.325 kPa So, 764.66 mmHg = 101.946 kPa
Ambient temperature: θa = 20 oC
Can No.: = 5
Initial mass of can: mf1 = 114.06 g
Mass of kettle: mk = 338.43 g
Mass of kettle and water: m1 = 1321.26 g
Initial temperature of water: θ1 = 20.4 oC
Final temperature of water: θ2 = 80.0 oC
Final mass of kettle and water: m2 = 1320.26 g
Final mass of can: mf2 = 105.27 g
Time/Temperature readings
Heating time (s)
30 sec. intervals Temp of water
(oC)
0 20.4
30 25.1
60 29.2
90 34.1
120 37.3
150 42
180 43.4
210 48.6
240 49.1
270 53.2
300 56.1
330 58.5
360 59.8
390 61.7
420 62.5
450 63.5
480 65.1
510 67.2
540 69
570 70.1
Heating time (s) Temp of water (oC)
600 72.6
630
Thermodynamics II
Contents
Introduction 2
Observations 2
Time/Temperature readings 2
Time/Temperature Plot 3
Calculations and Results 3
1) Enthalpy change of gas burned over the duration of the test 3
2) Heat transfer to the water in the kettle (Qw) 4
3) Heat transfer to the water which evaporates from the kettle (Qev) 4
4) Heat transfer to the kettle from initial to final state (Qk) 4
Find, as a fraction of 1, the values for 2, 3 and 4. 4
5) Air–Fuel Ratio 4
6) Enthalpy of combustion with the water formed by the combustion in the gas phase, (ΔhcoH2Ovap) 5
Using Δhco H2Ovap, find as a fraction of 1), the values for 2), 3) and 4). 6
Discussion and Conclusion 6
Introduction
The purpose of this experiment was to learn about the heat transfer process and determine the energy transferred from a gas flame to the water contained in a stainless steel kettle. The value calculated for the energy transferred is compared with the energy change associated with burning the gas (from calorific values) and the molar enthalpy of combustion of the gas mixture.
Observations
Atmospheric pressure: Pa = (767.15 – 2.49)mmHg = 764.66 mmHg 1 atm = 760 mmHg = 101.325 kPa So, 764.66 mmHg = 101.946 kPa
Ambient temperature: θa = 20 oC
Can No.: = 5
Initial mass of can: mf1 = 114.06 g
Mass of kettle: mk = 338.43 g
Mass of kettle and water: m1 = 1321.26 g
Initial temperature of water: θ1 = 20.4 oC
Final temperature of water: θ2 = 80.0 oC
Final mass of kettle and water: m2 = 1320.26 g
Final mass of can: mf2 = 105.27 g
Time/Temperature readings
Heating time (s)
30 sec. intervals Temp of water
(oC)
0 20.4
30 25.1
60 29.2
90 34.1
120 37.3
150 42
180 43.4
210 48.6
240 49.1
270 53.2
300 56.1
330 58.5
360 59.8
390 61.7
420 62.5
450 63.5
480 65.1
510 67.2
540 69
570 70.1
Heating time (s) Temp of water (oC)
600 72.6
630