Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 5th Sem 3150509 Fuels And Combustion Previous Question Paper
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?V (NEW) EXAMINATION ? WINTER 2020
Subject Code:3150509 Date:22/01/2021
Subject Name:Fuels and Combustion
Time:10:30 AM TO 12:30 PM Total Marks: 56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) State the different characteristics of a good fuel required for combustion.
03
(b) Discuss in short about the scenario of coal reservoirs in India.
04
(c) Write in brief about the theories suggested by geologists regarding the 07
mechanism of formation of coal.
Q.2 (a) Briefly explain various important properties of coal.
03
(b) State the different objectives and industrial applications of coal washing.
04
(c) Write a short note on origin of petroleum and natural gas.
07
Q.3 (a) Name the types of crude distillation methods used in petroleum industries.
03
(b) Enlist the refining products of petroleum.
04
(c) What are bio-fuels? Discuss in detail about the production process and 07
technologies required for bio-fuels.
Q.4 (a) Name the various methods to produce the hydrogen gas.
03
(b) Briefly explain the storage and handling of acetylene gas.
04
(c) What is producer gas? Discuss the different reactions involved in the 07
production of producer gas.
Q.5 (a) Explain the consequence of presence of nitrogen during combustion process.
03
(b) Define air to fuel ratio. Determine the air to fuel ratio when octane (C8H18) is 04
burned with 200% theoretical air.
(c) The following is the ultimate analysis of a sample of petrol by weight: Carbon 07
= 85%, Hydrogen = 15%. Calculate the ratio of air to petrol consumption by
weight if the volumetric analysis of the dry exhaust gas is: CO2 = 11.5%, CO
= 1.2%, O2 = 0.9%, N2 = 86%. Also find percentage excess air.
Q.6 (a) Define calorific value, gross calorific value and net calorific value of fuel.
03
(b) Calculate the heating value of Methane. It may be assumed the methane is 04
burnt in pure oxygen and does not contain any water vapour. The reaction
stoichiometry is
CH4 (g) + 2O2 (g) CO2 (g) + 2H2O (g)
The heat of formation data are as follows: H?f of CO2 (g) = ?393.5 kJ/mol,
H?f of H2O (g) = ?242.8 kJ/mol and H?f of CH4 (g) = ?74.8 kJ/mol
(c) Derive the expression for the first law analysis of reacting system for the 07
steady flow processes.
Q.7 (a) Briefly discuss the combustion of oil.
03
(b) State the two advantages and disadvantages of pulverized fuel firing.
04
(c) With neat sketch explain the concept of flame structure, propagation and 07
1
flammability limit.
Q.8 (a) List out the various characteristics of an efficient furnace.
03
(b) What do you mean by turn down ratio of burner? State the various types of 04
gas burner with their applications.
(c) With neat diagram discuss the working and industrial applications of fluidized 07
bed combustion process.
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This post was last modified on 04 March 2021