Reciprocating compressors: Scroll Compressor: Intake phase of Scroll compressor: Compression phase of scroll compressor Scroll Compressor Helical – Rotary (Screw) Compressors: Helical Rotary Compressor Centrifugal Compressor Open Compressor Hermatic Compressor: Semi hermetic compressor Cylinder Unloaders: Cycling on and off: Cycling scroll Compressors Slide Valve Inlet vanes Variable Speed: Condenser Refrigeration Cycle Air Cooled CondensersEffect of Sub cooling Types of Air – cooled condensers Evaporator condenser Water Cooled Condensers Description of Air Cooled condensers Centrifugal fan air cooled condenser Condensers Static Evaporative Condensers Water cooled Condenser Classification based on construction Tube in tube condensers Small tube in tube condensers Straight tube in tube condensers Shell and water cooled condensers Vertical shell and coil water cooled condensers Shell and tube water cooled condensers Vertical shell and tube condensers Surface condenserCounter flow in condensers Cross flow in condensers Air cooled condensers Cooling Tower Re circulated water system Condenser control Condenser capacity Condensing temperature control Expansion valve Objectives Expansion device Superheat sensor on dry expansion circuit Thermostatic expansion valve Automatic expansion valve Thermal electric expansion valve Capillary tube High pressure float valve Low pressure float valve TXV Control Operation of thermostatic expansion valve TXV Operation Evaporator Evaporator ControlSplitting finned – tube evaporator coils Row – split coil configuration Refrigeration accessories and their locations Cyberkeneticsolution. weebly. com Filtering and drying Pressure controls and their application Window air conditioners The refrigeration system of the window air conditioner Parts of the window air conditioners The refrigeration system of the window air conditioner : The refrigeration system of the window air conditioner: Types of Split A/c . Parts of a split air – conditioning system Air filter Outdoor unitExpansion valve Refrigerant piping or tubing Working of split ac Pressure sides Air Conditioning schematic system CONSTANT – VELOCITY METHOD: The various steps involved in this method are: 1.
Select suitable velocities in the main and branch ducts. 2. Find the diameters of main and branch ducts from airflow rates and velocities for circular ducts. For rectangular ducts, find the cross – sectional area from flow rate and velocity, and then by fixing the aspect ratio, find the two sides of the rectangular duct. 3.
From the velocities and duct dimensions obtained in the previous step, find the frictional pressure drop for main and branch ducts using friction chart or equation. 4. From the duct layout, dimensions and airflow rates, find the dynamic pressure losses for all the blends and fittings. 5. Select a fan that can provide sufficient FTP for the index run. 6. Balancing dampers have to be installed in each run. The damper in the run is left completely open, while the other dampers are throttled to reduce the flow rate to the required design values.
A = q/v, where A = duct cross sectional area , m2 Q = air flow rate m3/s, v = air speed m/s Velocity reduction method: If CFM, Q, and velocity V are known area A = Q/V, Since Area of a round duct = 22*d*d/(4*7)D = Square root of(4*7*A/22). So we get diameters as 31 and 32. If for a diameter of 31”, we have a height restriction of 20”. we refer to equivalent diameeter chart to get 40*20 duct. Note D equivalent = 1. 3*ab^0. 625/(a+b)^0.
25 Area of round duct =( 22*d*d/(4*7)D = 4*7*A/22)*0. 5 This is tabulation for converting round duct areas to square feet and square meters.Equivalent rectangular Ducts: This is an extract of equivalent rectangular ducts. We wil see how we can use a Ductulator to get these easily. Grille Outlets: Ceiling Diffuser Outlets: Linear slot diffuser: Perforated ceiling air diffusers are designed to be used as lay in tiles in a “T” bar or perforated ceiling.
The outlet consists of a square or rectangular flat perforated panel through which air may discharge vertically. Also an adaptor may be installed which houses directional deflectors to create horizontal ir patterns along the ceiling. Louver Face Diffuser: