vapour absorption refrigeration system is an energy efficient system of achieving refrigeration effect.
Vapor absorption refrigeration system is schematically demonstrated in following diagram.
i) WBT: Wet bulb Temperature twb : It is the temperature recorded by a thermometer when its bulb is covered by a wet cloth exposed to the air. ii) DPT: Dew point temperature tdp :It is the temperature of air recorded by thermometer, when the moisture (water vapour) present in its, begins to condensed. iii) DBT: Dry Bulb Temperature tdb : It is the temperature of air recorded by ordinary thermometer with a clean, dry sensing element .
Turbo Jet Engine
The air sucked by the compressor is not clean. It contains various types of solid, liquid and gaseous contaminants such as dust, dirt, moisture etc. The presence of contaminants may have high damaging effects such as corrosion, wear and tear on the finely finished mating surfaces of pneumatic components. Air lines may get chocked or damaged. Therefore, purification of air by removing oil, moisture and dust is done to protect the pneumatic system from failure, so that the system should work efficiently.
Brake Power Engine (BP)engine = 16.2 kW Brake Power developed when 1st Cylinder cut-off ( BP )2,3,4 = 11.5 kW Brake Power developed when 2nd Cylinder cut-off ( BP )1,3,4 = 11.6 kW Brake Power developed when 3 rdCylinder cut-off ( BP )1,2,4 = 11.68 kW Brake Power developed when 4 thCylinder cut-off ( BP )1,2,3 = 11.5 kW Indicated Power of 1st cylinder IP1 = (BP)engine - ( BP )2,3,4 = 16.2 – 11.5 = 4.7 kW IP2 = (BP)engine - ( BP )1,3,4 = 16.2 – 11.6 = 4.6 kW IP3 = (BP)engine - ( BP )1,3,4 = 16.2 – 11.68 = 4.52 kW IP4 = (BP)engine - ( BP )1,2,3 = 16.2 – 11.5 = 4.7 kW Indicated Power of Engine
A rotary-screw compressor is a type of gas compressor that uses a rotary-type positivedisplacement mechanism. They are commonly used to replace piston compressors where large volumes of high-pressure air are needed, either for large industrial applications or to operate highpower air tools. Rotary-screw compressors use two meshing helical screws, known as rotors, to compress the gas. In a dry-running rotary-screw compressor, timing gears ensure that the male and female rotors maintain precise alignment.
Effect of superheating: As shown in the figure a & b the effect of superheating is to increase the refrigerating effect, but this increase in the refrigerating effect is at the cost of increase in amount of work spent to attain upper pressure limit. Since the increase in work is more as compared to increase in refrigerating effect, therefore overall effect of superheating is to give a low value of C.O.P.
