Evidence shall show that knowledge has been acquired of safe working practices and determining thermodynamic parameters of refrigeration and air conditioning systems. All knowledge and skills detailed in this unit should be contextualised to current industry practices and technologies. KS01-EJ127A Thermodynamic parameters of refrigeration and air conditioning systems Evidence shall show an understanding of engineering mathematics fundamentals and refrigeration science to an extent indicated by the following aspects: T1 Arithmetic Rational and irrational numbers, surds SI units, conversion using unity brackets Laws of indices (base 10), scientific and engineering notation Estimations, errors and approximations, significant figures T2 Algebra Substitution +, -, x on simple polynomials. Simple indices Expanding brackets Factorising quadratics. Common factors, difference of two squares Simplifying algebraic fractions Transposition of engineering formulae Solving one variable equations Simple algebraic division. T3 Geometry Pythagoras Theorem Angles: degrees, radians. Parallel lines cut by a transverse Triangles: sum of angles, properties of equilateral and isosceles triangles Congruent triangles Similar triangles: ratio of corresponding sides Sin, cos, tan: ratios of a right angled triangle Sine and cosine rules Circles: circumference, arcs, chords, tangents, circle theorems Area and perimeter mensuration on above figures. T4 Coordinate geometry 2D plane; x-y axes, s-t axes Graph of linear function, y = ax + b. Functional notation, y = f(x) Straight line given slope and one point or given two points Linear equations: solving algebraically and geometrically Solving 2 linear functions simultaneously, algebraically and geometrically Line segment: length and mid point. T5 Engineering mechanics mass/density weight forces specific gravity equilibrium momentum friction loss velocity and speed energy in all forms mechanical advantage efficiency pressure/stress T6 Molecular theory changes of state sublimation expansion and contraction electron flow state of aggregation internal potential energy phase change diagrams T7 Thermodynamics temperature scales conservation of energy specific heat sensible, latent and super heat properties of steam enthalpy heat energy/temperature relationship heat balance on a body heat transfer conductivity calorimetry Peltier effect 1st and 2nd law of thermodynamics T8 Gas laws and liquids pressure Boyles law Charles law Volumetric relationship psychrometrics latent heat of vaporisation relative humidity air conditioning processes dynamic pressure loss velocity and static pressure bourdon tubes density and relative density Archimedes principle Bernoulli’s Equation manometers absorption refrigeration centrifugal compression external work of a liquid pressure volume diagrams isothermal and adiabatic processes polytropic processes Dalton’s law of partial pressure T9 Vapour compression pressure/enthalpy relationship entropy characteristics of the evaporation, condensation, compression and pressure drop phases co-efficient of performance theoretical/practical cycles characteristics of refrigerants theoretical power input pressure losses heat exchange effects of condensing condition changes sub-cooling and super-heating |