Articles Posted in the " Gas Refrigeration " Category

  • * Analysis of Simple aircraft cooling system-2

    * Analysis of Simple aircraft cooling system-2

    Analysis of Simple aircraft cooling system-2 (iii) Calculation of T4 after the HEAT EXCHANGER T4 temperature after the cooler (heat exchanger) on the basis effectiveness of the heat exchanger which can be assumed as 80 % if not given. ЄHEX =( T3—T4)/( T3 — T2) = Actual temp drop/Theoretical temp drop possible (iv) Calculation of temperatures T5 […]


  • Interview Short Question Answers on Aircraft Cooling

    Interview Short Question Answers on Aircraft Cooling

     Interview Short Interview Question Answers on Aircraft Cooling  Why Is The Necessity of Aircraft cooling? In an aircraft, cooling systems are required to keep the cabin temperatures at a comfortable level. Even though the outside temperatures are very low at high altitudes, still cooling of cabin is required due to: (i)  Large internal heat generation […]


  • * Short Interview Question Answers on Air Refrigeration

    * Short Interview Question Answers on Air Refrigeration

    Short Interview Question Answers on Air Refrigeration  Q. Compare open cycle and closed cycle air Refrigeration systems. Why closed cycle is called a dense system?  OPEN CYCLE: The conditioned air comes in physical contact with the passengers, this air refrigeration cycle is an open cycle. In this, air picks up moisture from the cabin and […]


  • * BOOT STRAP -REGENERATIVE AIRCRAFT COOLING SYSTEMS

    * BOOT STRAP -REGENERATIVE AIRCRAFT COOLING SYSTEMS

    BOOT STRAP – REGENERATIVE AIRCRAFT COOLING SYSTEMS First Method Boot Strap Aircraft cooling : Two types Without evaporative cooling, With evaporative cooling FIG. BOOT STRAP SYSTEM ON TEMPERATURE ENTROPY CHART This Bootstrap system has two compressors, two heat exchangers and one turbine. Normally second compressor is run by the expansion turbine turbine. System with evaporative […]


  • *Analysis of aircraft cooling systems-1

    *Analysis of aircraft cooling systems-1

    Analysis of aircraft cooling systems-1 Refrigerant is air in all the systems of the aircraft cooling. FIG. SIMPLE AIRCRAFT COOLING SYSTEM ON TEMP -ENTROPY CHART  Mathematical analysis of Simple Aircraft Cooling System—-1 Properties of air are cP =1.005 k J/kg 0c cv =0.714 k J/kg 0c γ =  1.4 =Cp/Cv Rair=287 k J/kg K 1kWh […]


  • *Comparison of air refrigeration and vapor refrigeration

    *Comparison of air refrigeration and vapor refrigeration

    Comparison of air refrigeration and vapor refrigeration Air refrigeration is based on bell Coleman Cycle and is used in all the air crafts. It causes cooling by sensible effect.Though it has a low COP but certain amount of power is saved in carrying only (1/10)th of refrigeration equipment load as compared to that in vapor […]


  • Short Interview Question Answers on Air and Vapor Refrigeration

    Short Interview Question Answers on Air and Vapor Refrigeration

    Short Interview Question Answers on Air  and Vapor  Refrigeration Q. What is Bell Coleman Cycle or Reversed Brayton Cycle or Reversed Joule Cycle or Gas Refrigeration Cycle?  It is a cycle which consists of two isen-tropic processes and two isobaric processes. Since in this cycle the working substance is air (OR gas) work of expansion […]


  • Interview Short  Question Answers on Aircraft Refrigeration

    Interview Short Question Answers on Aircraft Refrigeration

     Interview Short Question Answers on Aircraft Refrigeration  Q.  WHY IS AIR USED AS REFRIGERANT IN AIRCRAFT?  (i) Air is cheap, safe, non-toxic, non corrosive, inert and non-flammable. Leakage of air is not a problem (ii). Cold air from the turbine can directly be sent to cabin for cooling. Thus it eliminates the low temperature heat exchanger […]


  • * Interview Short Question Answers on Air Refrigeration

    * Interview Short Question Answers on Air Refrigeration

    Interview Short  Question Answers on Air Refrigeration Before defining COP , two terms are to be understood. DEFINE REFRIGERATING EFFECT OR COOLING EFFECT, N It is heat removed by 1 kg of refrigerant from the products to be cooled. It is represented by ‘N ‘. It is expressed as k J/kg.  GIVE DEFINITION OF WORK […]


  • Open and Closed Air Refrigeration Cycles

    Open and Closed Air Refrigeration Cycles

    Open and Closed Air Refrigeration Cycles  TWO WAYS OF OPERATING OF BELL COLEMAN CYCLE (i) Open air refrigeration cycle: When cooled air from the turbine enters the cabin and comes in physical contact with the occupants. It is not much in use because of moisture added to air in the cabin. (ii) Closed air refrigeration cycle OR dense […]