# UEENEEJ127A Establish the thermodynamic parameters of refrigeration and air conditioning systems

**AIBT**

**UEENEEJ127A: Establish the thermodynamic parameters of refrigeration and air conditioning systems**

**&**

**UEENEEJ165A: Evaluate thermodynamic and fluid parameters of refrigeration systems**

**Assessment**

written activity

For this activity you are required to answer each of the following questions. These answers should be 8 typed lines = 100 words, or 10 lines of handwritten text = 1⁄3of a foolscap page.

- T1 Arithmetic
- What are rational and irrational numbers and surds?
- What are SI units?
- How would you use unity brackets for conversions?
- Outline the laws of indices (base 10).
- What is scientific and engineering notation?
- What are estimations, errors and approximations and significant figures?

- T2 Algebra
- What is substitution used for in algebra?
- What do you need to do when you are adding or subtracting simple polynomials?
- Solve the following polynomial multiplication: x(x+3)
- What are indices?
- Expand the following: 2xy(3x+2)
- Factorise the following expression: 18x + 12y = 6(3x + 2y)
- What is meant by the term common factor?
- Briefly discuss the difference of two squares.
- Simply the following algebraic fraction: (5x5)/(3x3)
- Transpose the following engineering formula to find the value of R: v=iR
- Solve the following variable equation: 4b+5 = 1+5b
- Solve the following algebraic division: 8x
^{2 }/2 - T3 Geometry
- What is Pythagoras Theorem?
- What is the difference between degrees and radians?
- Briefly discuss the relationship of the angles in parallel lines that are cut by a transverse.
- How would you calculate the sum of angles on a triangle?
- What are the properties of equilateral and isosceles triangles
- What are congruent triangles?
- Briefly describe the ratios of corresponding that occurs in similar triangles.
- What is the formula used to calculate the sine (sin) of a right-angled triangle?
- What is the formula used to calculate the cosine (cos) of a right-angled triangle?
- What is the formula used to calculate the tangent (tan) of a right-angled triangle?
- What is the ratios for the angles in a right-angled triangle?
- What are the rules of sine and cosine?
- What is the circumference of a circle?
- What are the 2 methods used to measure arcs?
- In geometry, what is meant by chord?
- What is meant by tangent (in geometry)?
- What is the formula used for determining the area of a triangle?
- What is the formula used for determining the area of a circle?
- How can you calculate the perimeter of a triangle?
- How do you calculate the perimeter of a circle?
- T4 Coordinate geometry
- In relation to a 2D plane, what are x-y axes and s-t axes?
- Provide an example of a y = ax + b linear graph.
- Briefly discuss the functional notation y = f(x).
- What is the formula used to determine a straight line if you are given the slope of the line and one point?
- Explain how to determine the slope of a straight line when you have been given two points.
- Solve the following linear equations algebraically: 5x - 6 = 3x - 8
- Solve the following linear equations geometrically: y = 2x + 4, y = 3x + 2
- Solve the following 2 linear functions simultaneously, algebraically: y = 2x + 2, y = x - 1
- Solve the following 2 linear functions simultaneously, geometrically: y = -x - 2, y = x + 3
- Determine the length of a line segment from (-1, 1) to (3, 4)
- Determine the midpoint from the above line segment.
- T5 Engineering mechanics. Briefly discuss each of the following:
- 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. Briefly discuss each of the following terms in relation to molecular theory:
- Changes of state
- Sublimation
- Expansion and contraction
- Electron flow
- State of aggregation
- Internal potential energy
- Phase change diagrams
- T7 Thermodynamics. Briefly discuss each of the following terms in relation to 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. Answer the following questions briefly:
- What is pressure in relation to gas and liquids?
- Outline Boyles law.
- Describe Charles law.
- What is Volumetric relationship?
- What are psychrometrics?
- What is “latent heat of vaporisation”?
- What is relative humidity?
- What processes can be used for air conditioning?
- Define “dynamic pressure loss”.
- Define velocity and static pressure.
- What are bourdon tubes?
- Define the terms density and relative density.
- What is Archimedes principle?
- What is Bernoulli’s Equation?
- What are manometers?
- What is absorption refrigeration?
- What is centrifugal compression?
- Outline the external work of a liquid?
- What are pressure volume diagrams?
- Define isothermal and adiabatic processes?
- What are polytropic processes?
- What is Dalton’s law of partial pressure?
- T9 Vapour compression
- What is the pressure/enthalpy relationship?
- Define entropy?
- What are the characteristics of evaporation, condensation, compression and pressure drop phases?
- What is the co-efficient of performance?
- Outline the theoretical/practical cycles?
- What are the characteristics of refrigerants?
- What is theoretical power input?
- Define pressure loss.
- Define heat exchange.
- What are the effects of condensing condition changes?
- Describe the terms sub-cooling and super-heating?

OBSERVATION/Demonstration

The following activities will need to be demonstrated while completing a representative body of work in appropriate workplace or simulated environment, and will need to be completed within the timeframes typically expected of the discipline, work function and industrial environment.

You will need to demonstrate your skills and knowledge on at least two occasions.

- To begin you need to prepare to determine thermodynamic parameters of refrigeration and air conditioning systems. In order to prepare adequately for the task you will need to:
- Identify and understand the WHS/OHS procedures for your given work area.
- Follow all established WHS/OHS risk control measures and procedures during work activities.
- Establish the scope of work by sourcing and obtaining the expected operating conditions from documentation or from your work supervisor.
- Seek advice from the work supervisor to ensure the coordination of work.
- Obtain and check all tools, equipment and testing devices needed to determine the basic operating conditions for correct operation and safety.
- Obtain the expected operating conditions from documentation or from work supervisor to establish the scope of work to be undertaken.

- Then you are to determine the thermodynamic parameters of refrigeration and air conditioning systems. In order to do this safely and effectively you are required to:
- Follow all established WHS/OHS risk control measures and procedures relating to the work activities.
- Conduct the measurement of thermodynamic system operating parameters in strict accordance with WHS/OHS requirements and established safety procedures for your organisation.
- Check the system and isolate where necessary, in line with WHS/OHS requirements and procedures.
- Using established procedures, determine the actual and specified range of thermodynamic parameters from measured and calculated values as they apply to particular refrigeration or air conditioning systems.
- Discuss methods for dealing with unexpected situations with the appropriate person or persons
- Document methods for dealing with unexpected situations in line with organisational procedures.
- Deal with unexpected situations safely, in line with established procedures and with the approval of an authorised person.
- Determine the thermodynamic parameters without damage to apparatus, circuits, the surrounding environment or services at all times using sustainable energy practices.

- Finally you will need to document the determined thermodynamic parameters. To do this effectively you will need to demonstrate your skills by:
- Following all WHS/OHS work completion risk control measures and procedures.
- Clean the worksite and equipment in line with organisational procedures and expectations.
- Make the worksite and equipment safe after cleaning.
- Document the thermodynamic parameters including the identification of any parameter that is not within the specified range for the system.
- Notify the work supervisor of the completion of the work in line with established procedures.

Once you have completed this activity you will need to provide your trainer/assessor with all documentation created.

Questions

The following questions may be answered verbally with your assessor or you may write down your answers. Please discuss this with your assessor before you commence. Short Answers are required which is approximately 4 typed lines = 50 words, or 5 lines of handwritten text.

Your assessor will take down dot points as a minimum if you choose to answer them verbally.

Answer the following questions either verbally with your assessor or in writing.

- Why do you need to identify and understand the WHS/OHS processes and procedures for a given work area when establish the thermodynamic parameters of refrigeration and air conditioning systems?
- Where would you obtain the expected operating conditions from?
- Why do you need to obtain the expected operating conditions?
- What tools, equipment and testing devices are needed in order to establish the thermodynamic parameters of refrigeration and air conditioning systems?
- Why do you need to follow the established WHS/OHS risk control measures and procedures?
- What is the procedure for measuring the thermodynamic system operating parameters?
- How would you check the system?
- Why might you need to isolate the system?
- How would you determine the actual and specified range of thermodynamic parameters from measured and calculated values?
- Who would you discuss the methods for dealing with unexpected situations with?
- How should unexpected situations be dealt with?
- What damage should be avoided when determining the thermodynamic parameters?
- What procedures MUST be followed at all times?
- When all tasks have been completed what do you need to do?
- Why do you need to document all thermodynamic parameters including those that are not within the specified range?
- Who would you notify when work was completed?