Certification Assistance for Marine Engineers
Canadian
Second Class ME
Applied Heat (Thermo)
In Canada, Transport Canada administers the Marine Engineering examination process; visit the Training Page for details on the process. The actual exam consist of nine (9) questions randomly drawn from a question bank of the various subject. Six (only) must be answered in a 3.5hrs time frame. The exam questions are similar to these, presented below, and are drawn heavily from similar question in the Reed's Marine Engineering series of books.
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Disclaimer
Transport Canada has ask us to advise users of this webpage to keep in mind that these questions are not the exact questions found in their exams. Martin's Marine Engineering Page - www.dieselduck.net is not affiliated with Transport Canada and these questions have been gathered from various sources.
01 Mass analysis of a fuel is 84.6% carbon, 11.4% hydrogen,
0.4% sulphur, 2.4%oxygen, and 1.2% impurities. Calculate the heating value
of the fuel and the theoretical mass of air required for complete combustion
of 1kg of fuel.
Take mass analysis of air as oxygen 23% and nitrogen 77%
Element/heating value(MJ/kg)/relative atomic mass
hydrogen/144/1
carbon/33.7/12
sulphur/9.3/32
oxygen/0.0/16
02 The pressure in a steam condenser is 4.0 kPa, the
temperature is 20.43*C and the internal volume is 12 m3. The dryness
fraction of the steam is 0.8. - R air = 0.287 kJ/kgK
Calculate
(a)mass of air present in the condenser
(b) mass of steam in the condenser
03 The nozzle of a turbines inclined at an angle of 22* to
the plane of the rotor wheel, the blade entrance angle being 40* and the
steam velocity leaving the nozzles is 760 m/s. Assume the blade entrance and
exit angles are equal and that no friction losses occur as the steam flows
over the blades.
Determine graphically or analytically:
(a) blade velocity assuming the steam enters the blade without shock.
(b) blade efficiency
04 Steam is admitted to an engine at a pressure of 750kPa,
exhausted at 150 kPa and the cut-off takes place at 0.375 of the stroke.
Calculate hypothetical mean pressure
05 In a refrigeration plant, the specific enthalpy of the refrigerant as it leaves the condenser is 135 kJ/kg, and as it leaves the evaporator 320 kJ/kg. If the mass flow of the refrigerant is 5 kg/min, calculate refrigerating effect per hour.
06 An ingot of dimension 0.5 x 1 x 3 m has just been removed
from the soaking pit of a steel mill and its temperature is 600*C. Assuming
black body radiation, calculate the energy radiated from the entire surface
of the ingot each second.
Note: Power, (W) = e & A T to the fourth
&=5.67 x 10 to the -8
07 A gasoline engine has a compression ratio 9.5 to 1. The temperature of the fuel/air mixture at the beginning of the compression stoke is 24*C and the charge is compressed polytropically according to PV1.36 = constant. Calculate temperature and pressure of the mixture at the end of compression stroke. Take atmosphere to be 100kPa.
- the above questions submitted by G-Man, submit yours here
01 - When developing a certain power, the specific fuel consumption of an internal
combustion engine is 0.255 kg/kwh. Mechanical efficiency = 86%. Calorific value of
the fuel is 43.5 MJ/kg.
a) Calculate indicated thermal efficiency and brake thermal efficiency.
02 - A copper sphere has a diameter of 40 mm. Calculate the increase in volume when the temperature is raised 180 C. Co-efficient of expansion = 0.0000167/C
03 - Using steam table find the specific enthalpy and volume of 1 kg steam at pressure 24 kg and dryness fraction 0.86.
Calculate additional energy required to completely dry the steam.
04 - During a certain part of a liquefaction process, air is expanded adiabatically through a turbine from a pressure of 8000 KPA and temperature 15 C to a pressure of 100 KPA. Adiabatic index = 1.4 Calculate final temperature.
05 - Single cylinder steam engine, Bore = 200mm, stroke = 300mm running at 3.5 revs/sec, develops 510 KPA mean effective pressure. Calculate indicated power.
06 - Cold Room 30m x 23m x 3m
inside temperature = -30 C
Outside temperature = 21 C
Ground temperature = 10 C
Walls and ceilings insulated with 25cm granulated cork h = 0.049 w/mk
Floor insulated with cork board 15 cm thick h = 0.043 w/mk
Calculate heat transfer per hour.
07 - Mass analysis of fuel A = 88.5% Carbon, 11.5 % hydrogen
Fuel B requires 6% more air than fuel A for combustion. Calculate mass analysis of fuel B using following values.
Atomic Weights = Carbon = 12
Hydrogen = 1 oxygen = 16
Mass content of oxygen in air = 23%
08 - The nozzle of a turbine is inclined at an angle of 20 C to the plane of the rotor wheel and the blade entrance angle is 33 C. The steam leaves the nozzle at a velocity of 450m/s and the mean diameter of the rotor blade ring is 600mm
Determine either graphically or analytically
-
The linear velocity of the blades so that the steam enters without shock.
-
Rotational speed of rotor in revs/sec.
- the above questions submitted by BP, submit yours here