Guidance

Applied Heat Written Examination Syllabus

Published 6 May 2014

The expected learning outcome is that the student:

1. Thermodynamic Systems

1.1 Defines and applies the fundamental concepts of thermodynamic properties to a system.

1. Defines a thermodynamic system.
2. Distinguishes between open and closed thermodynamic systems giving examples.
3. Defines Heat and Work with reference to a thermodynamic system.
4. States the conservation of energy in thermodynamic terms and identifies it as the First Law of Thermodynamics.
5. Defines enthalpy in terms of internal energy and flow work.
6. Defines a non-flow system and derives the non-flow energy equation Q - W = ΔU
7. Defines a steady flow system and derives the steady flow energy equation Q - W = ΔH + ΔKE
8. Solves problems involving closed and open systems 1.1.1 to 1.1.7.

2. Thermodynamic Processes

2.1 Defines and applies the fundamental properties of thermodynamics to a process.

1. Recalls Boyle’s and Charles’ Law and the combination law.
2. Recalls the Equation of State.
3. Derives the relationship between p, V and T for polytropic and adiabatic processes T₂/T₁ = (P₂^{n - 1/n})/P₁ = (V₁^{n - 1})/V₂ and T₂/T₁ = (P₂^{δ - 1/δ})/P₁ = (V₁^{δ - 1})/V₂
4. Derives graphically and analytically the polytropic index -n’.
5. Defines a reversible process.
6. States the conditions to be satisfied for a process to be reversible.
7. Defines a reversible process carried out with an ideal gas as follows:
   1. Constant volume process;
   2. Constant pressure process;
   3. Isothermal process;
   4. Isentropic or Adiabatic or constant heat process;
   5. Polytropic process;
   6. Defines Isentropic as Reversible Adiabatic and identifies the difference between - Isentropic and non-reversible adiabatic.
8. Derives the expression for the work transfer and heat transfer for each of, or combination of processes in 2.1.7.
9. Defines the specific head of a gas and shows the difference between specific heat at constant pressure and constant volume.
10. Shows the relationships ΔU = C_v, Δh = C_p, δ = C_p/C_v, R = C_p - C_v and is able to combine these relationships by substitution.
11. Solves problems relating to 2.1.1 to 2.1.10.
12. Discusses the concept of entropy as a thermodynamic property of a perfect gas.
13. Applies change of entropy. (mC_pln)T₂/T₁, (mC_vln)T₂/T₁
14. Defines heat transfer and work transfer and represents on p - v and T - S diagrams.
15. Shows the processes in 2.1.7 on T - S diagram.
16. Solves problems 2.1.12 to 2.1.15.
17. States Avogadro’s Law.
18. Defines kg - mol and uses it in the Equation of State.
19. Defines “Molar Volume” and gives its value at S.T.P.
20. Derives the Universal Gas Constant R and its relation to with M and R.
21. Solves problems relating to 2.1.17 to 2.1.20.

3.   Heat Engine Cycles

3.1 Discusses the concept of heat engine cycles.

1. States the 2nd law of thermodynamics and relates this to the heat engine.
2. Describes the Carnot Cycle with reference to a heat engine.
3. Derives the thermal efficiency of a Carnot Cycle.
4. Application of Carnot’s principle to show that no cycle can be more efficient without contravening the 2nd law.
5. Describe the ideal ie. engine cycles, Otto, Diesel, Dual Combustion and Joule and relates to p - v and T -S diagrams
6. Derives expressions for thermal efficiency, i.m.e.p. and net-work done, for the cycles in 3.1.5.
7. Derives Air Standard Efficiency. 8.  Solves problems relating to 3.1.2 to 3.1.7.
8. Describes the practical counterparts of the cycles identified at 3.1.5.
9. Discusses simple ideal and actual open and closed cycle gas turbines, with two stage compressors and turbines, including reheat and optional heat exchanger.
10. Discusses heat exchanger “Effectiveness” and hence derives “Thermal Ratio”.
11. Expresses 3.1.10 with respect to T - S diagrams.
12. Derives cycles thermal efficiencies, work and heat transfer with respect to 3.1.10.
13. Solves problems relating to 3.1.10 to 3.1.13.

4. I.C. Engine Performance

4.1 Discusses internal combustion engines and engine performance.

1. Recalls the following engine powers and formulae:
   1. Indicated power;
   2. Brake power;
   3. Friction power.
2. Recalls indicated and brake mean effective pressure and how to derive them.
3. Shows that brake mean effective pressure is directly-proportional to engine torque and independent of the engine speed.
4. Determines the distribution of energy in an engine and produces a heat balance account.
5. Describes the Morse Test and calculates power from given data.
6. Recalls mechanical efficiency, indicated thermal efficiency, brake thermal efficiency.
7. Defines specific fuel consumption.
8. Sketches typical performance curves for I.C. engines. 9.Solves problems relating to 4.1.1 to 4.1.8.

5. Reciprocating Air Compressors

5.1 Discusses and describes the use of reciprocating air compressors.

1. Sketches and describes the basic cycle for a single stage compressor running without clearance.
2. Derives the expression for indicated work transfer.
3. Sketches and describes the basic cycle for a single stage compressor running with clearance.
4. Derives the expression for net indicated work transfer given the area under the curve.
5. Derives expressions for volumetric efficiency.
6. States the effect of compressive index on net indicated work transfer.
7. Relates ideal (isothermal) and actual (polytropic) compression cycles and derives isothermal efficiency.
8. Discusses multi-stage compression and understands the advantages of same.
9. Defines conditions of minimum work with multi-stage compression.
10. Recognises multi-stage compression when 5.1.9 does not apply.
11. Distinguishes between indicated and input power requirements.
12. Discusses heat transfer during compression and interstage cooling.
13. States the significance of Clearance Ratio.
14. Solves problems relating to 5.1.1 to 5.1.13.

6. Combustion

6.1 Discusses combustion of solid, liquid and gaseous fuels by mass and by volume in terms of air requirements, excess air and products of combustion.

1. Recalls the chemistry definitions: Atom, Molecule, Compound, Atomic Mass, Molecular Mass.
2. Derives the equations of combustion by mass.
3. Derives the equations of combustion by volume for gaseous fuels.
4. Recalls stoichiometric and actual air requirements.
5. Understands and applies Avogadro’s Hypothesis to exhaust and flue gas analysis.
6. Determines total flue gas and dry flue gas analysis by mass and by volume.
7. Determines air supply from flue gas analysis.
8. Derives the proportional gravimetric constituents of a fuel from flue gas analysis.
9. Determines the exhaust products resulting from insufficient air supply and determines C burned to CO and C burned to CO.
10. Determines the approximate HCV and LCV of a fuel from the heat energy released by the various constituents.
11. Applies Dalton’s laws to stoichiometric and other mixtures of gaseous fuels and air.
12. Determines the mean molecular mass of a mixture of gases and the specific gas constant for the mixture.
13. Determines the “dew point” of water vapour from flue gas analysis.
14. Determines heat carried away in flue gases and determines heat transfer to gas to air and gas to water heat exchanges.
15. Solves problems relating to 6.1.1 to 6.1.14.

7. Heat Transfer

7.1 Discusses modes of heat transfer by conduction, radiation convection.

1. States Fourier’s Law for conductive heat transfer.
2. Applies 7.1.1 to single flat plate and composite flat plate and derives an expression for conductive heat transfer through composite flat plates.
3. Applies given formulae for heat transfer through thick cylinders.
4. Relates 7.1.3 to single and double lagged pipes, spheres and hemispherical ends of cylinders.
5. Discusses heat transfer through boundary layers and applies thermal conductance coefficients.
6. Determines the overall heat transfer coefficient “U” for composite flat plates and composite lagged pipes etc, using thermal conductivity and surface heat transfer coeff.
7. States the Stefan Boltzmann constant for heat transfer by radiation. Defines “black body” radiation and “emissivity factor” and applies this to a simple system.
8. Solves problems relating to 7.1.1 to 7.1.7.
9. Solves problems involving heat exchangers using “log mean temp difference”.

8. Properties of Steam and Steam Cycles

8.1 Understands constant pressure steam formation, and the use of thermodynamic property tables and charts.

1. Understands steam formation, steam terms and demonstrates the use of thermodynamic property tables including interpolation of tables.
2. Recalls the formulae for boiler efficiencies.
3. Recalls formulae for “equivalent evaporation” and explains its use.
4. Determines the heat energy distribution in a boiler plant and compiles a heat balance account.
5. Applies thermodynamic properties of water and steam to solve problems on mixtures, evaporators and steam generators.
6. Discusses the concepts of throttling.
7. Discusses the concepts of entropy of liquid, vapour and super heated steam and their evaluation from steam tables and from given formulae.
8. Understand the construction and demonstrates the use of H-S and T-S charts.
9. Discusses the isentropic expansion of steam and demonstrates this process on H-S and T-S diagrams.
10. Discusses the Carnot Vapour Cycles and modifications resulting in the basic Rankine Cycle.
11. Discusses the improvements to the basic cycle from super-heating, reheating and feed heating.
12. Relates these cycles to P.V. and T.S. diagrams.
13. Derives an expression for thermal efficiency when operating on the above cycles.
14. Determines feed pump work and relates this to thermal efficiency of the plant.
15. Describes bled steam feed heating and determines heat transfer by steam and feed water through multi-stage contact and surface feed heating.
16. States Dalton’s Law of partial pressures, its application to partial volumes and its application to steam/air mixtures in condensers and associated plant.
17. Solves problems relating to 8.1.1 to 8.1.16 by calculation, thermodynamic tables and H- S charts.

9. Nozzles and Steam Turbines

9.1 Understand the use of steam as a working fluid and discusses its behaviour during flow through nozzles under equilibrium conditions.

1. Applies steady flow energy equation to flow through steam nozzles and derives throat and exit velocities =
2. Distinguishes between isentropic and actual enthalpy drop in nozzles and defines nozzle efficiency.
3. States reasons for change of nozzle form and use of convergent and convergent/ divergent sections.
4. Recognises critical pressure ratios for nozzle flow and applies the same, from given formulae.
5. Solves problems on 9.1.1 to 9.1.4 with equal regard to mass flow rates and flow areas.
6. Discusses compounding arrangements for simple turbines.
7. Recalls blade velocity diagrams for simple impulse turbine.
8. Defines kinetic or friction losses, leaving losses and derives expressions for same.
9. Constructs blade velocity diagrams for a Curtis stage.
10. Derives expressions for stage power, stage/diagram efficiency and stage axial thrust for a velocity overall and pressure compounded turbines.
11. Derives an expression for degree of reaction.
12. Constructs blade velocity diagram for a reaction turbine pair.
13. Defines mean blade height and calculates blade height.
14. Calculates number of stages from given steam conditions for reaction blading only
15. Shows the effect of blade friction, (blade velocity coefficient) and blade speed ratio.
16. Solves problem relating to 9.1.7 to 9.1.15.

10. Refrigeration

10.1 Understands the concept of a reversed heat engine cycle and its application to refrigerating plant and heat pump, and recognises the properties of common refrigerants.

1. Recalls the basic vapour compression refrigeration cycle.
2. Recalls the use of thermodynamic tables including the interpolation of values.
3. Applies the concepts of entropy and its evaluation from tables and from given formulae.
4. Relates vapour compression cycles of p-H and T-S axes.
5. Relates reversed Carnot cycle on p-H and T-S axes.
6. Shows effects of superheating at evaporator outlet and undercooling at condensor outlet and relates to p-H and T-S.
7. States relationship between mass flow rate of refrigerant, refrigerating effect, cooling load.
8. Defines COP for heat pump and refrigerator.
9. Derives expressions for COP of actual plant and compares to COP of plant working on reversed Carnot cycle. 10.   Defines volumetric efficiency of compressor and its effect on cylinder dimensions.
10. Solves problems relating to 10.1.1 to 10.1.9.
11. Understands the application of intermediate liquid cooling and solves simple problems involving flash chambers.