This module concerns basic Fluid Mechanics, specifically an introduction to the study of liquid statics and dynamics, vapour compression refrigeration cycles and heat transfer in heat exchangers. The module will equip learners with the necessary theory and knowledge in fluid mechanics, refrigeration and heat transfer mechanisms in HVAC heat exchangers. It will also prepare them for further study in these areas.
Fluid Properties: • Bulk modulus of a liquid, pressure, compressibility. • Pascal’s Law and its’ application to pressure transmission in a liquid at rest. • Density and viscosity. Gases: • Basic gas laws, specific and universal gas constants. • Isothermal, polytropic and adiabatic changes. • Compressor construction and volumetric efficiency. • Single and two-stage compression. Dynamic fluid systems: • Continuity equation. • Pressure and head • Bernoulli’s equation for an Ideal fluid • Losses in flow systems, • Bernoulli’s equation for a real fluid • Laminar and turbulent flow • Reynolds number • Darcy’s equation for losses in pipes, Moody chart and friction factor • Major and minor pipe losses, equivalent length of pipes and fittings • Construction of common valves for isolation and throttling • Pipe sizing Vapour compression refrigeration: • Descriptive principles and theory of operation of vapour compression refrigeration systems. • Application to condenser, evaporator and expansion valves • Heat pumps Absorption refrigeration • The principles of single and multi-stage absorption refrigeration cycles • Practical application to absorption chillers in HVAC systems Heat Exchangers • Theory and practical design of water/water and air/air heat exchangers used in building engineering water and air systems.
