Learning Outcome 1
Apply dimensional analysis to energy and mass transfer relationships
1. The surface heat transfer coefficient 'a' in forced convection in a pipe is considered to depend on the diameter of the pipe D, velocity of the fluid V and the fluid properties - density r, viscosity m, specific heat capacity Cp and thermal conductivity k.
Obtain an equation relating these quantities.
Learning Outcome 2
Evaluate heat transfer mechanisms
2. The three mechanisms of transferring heat between surfaces and fluids are applied in different situations.
Evaluate their effectiveness when being applied to industrial steam raising plant.
Learning Outcome 3
Determine heat transfer coefficients using experimental and tabulated data
3. Using a water tube counter flow heat exchanger, determine the heat transfer coefficients.
Produce a report of no more than 850 words on your experience during the experiment, highlighting any differences between the theory and practical outcomes.
Learning Outcome 4
Evaluate various types and layout of recuperators
4. There are many types of recuperators, you are required to select 4 different types and then evaluate their performance, layout and applications.
Learning Outcome 5
Estimate heat transfer performance
5. An exhaust pipe is 85 mm diameter and it is cooled by surrounding it with a water jacket. The exhaust gas enters at 450oC and the water enters at 10oC. The surface heat transfer coefficients for the gas and water are 300 and 1500 W/m2 K respectively. The wall is thin so the temperature drop due to conduction is negligible. The gasses have a mean specific heat capacity Cp of 1130 J/kg K and they must be cooled to 100oC. The specific heat capacity of the water is 4190 J/kg K. The flow rate of the gas and water is 250 and 1450 kg/h respectively.
Calculate:
a. the required length of pipe for Parallel flow
b. the required length of pipe for Contra flow
c. estimate the performance of the heat transfer in both cases
Learning Outcome 6
Specify recuperator type, size and fluids for given applications
6. A gas turbine requires air supplied to its combustion chamber at 350oC.The turbines exhaust gas temperature is 750oC
Identify the type, size, effectiveness and transfer fluid to achieve this
Cp for exhaust gas = 1.15kJ/kg K
Cp for air = 1.005kJ/kg K
Assume mass flow of exhaust gas is constant
Learning Outcome 7
Derive combustion equations
Analyse products of combustion
7. A sample of dry anthracite coal has the following composition by mass.
C = 90%; H = 3%; O = 2.%; N = 1%; S = 0.5%; ash = 3%.
Calculate:
a. The stoichiometric air to fuel ratio
b. The actual air to fuel ratio, when 20% excess air is supplied
c. The dry and wet gas analysis of the products of combustion by mass and volume, when 20% excess air is supplied
Learning Outcome 8
Determine calorific value
8. 1kg of kerosene was found to contain 86% carbon and 14% hydrogen giving a temperature change of 8.8902 K. The specific heat Cp of water is 4.186kj/kg. Standard temperature is 25 Deg C.
Calculate:
a. The higher calorific value of the gas
b. The net calorific value
c. The lower calorific value