2 History Of Refrigeration – Development Of Refrigerants And Compressors 1 Version 1 ME, IIT Kharagpur
The objectives of the present lesson are to introduce the student to the history of refrigeration in terms of: 1. Refrigerant development (Section 2.2):
i. ii. iii. Early refrigerants (Section 2.2.1) Synthetic fluorocarbon based refrigerants (Section 2.2.2) Non-ozone depleting refrigerants (Section 2.2.3)
2. Compressor development (Section 2.3):
i. ii. iii. iv. v. vi. Low-speed steam engine driven compressors (Section 2.3.1) High-speed electric motor driven compressors (Section 2.3.1) Rotary vane and rolling piston compressors (Section 2.3.2) Screw compressors (Section 2.3.2) Scroll compressors (Section 2.3.2) Centrifugal compressors (Section 2.3.3)
At the end of the lesson the student should be able to: i. ii. iii. iv. v. vi. vii. State the importance of refrigerant selection List various refrigerants used before the invention of CFCs List various CFC refrigerants and their impact on refrigeration State the environmental issues related to the use of CFCs State the refrigerant development after Montreal protocol List important compressor types List important landmarks in the development of compressors
The development of refrigeration and air conditioning industry depended to a large extent on the development of refrigerants to suit various applications and the development of various system components. At present the industry is dominated by the vapour compression refrigeration systems, even though the vapour absorption systems have also been developed commercially. The success of vapour compression refrigeration systems owes a lot to the development of suitable refrigerants and compressors. The theoretical thermodynamic efficiency of a vapour compression system depends mainly on the operating temperatures. However, important practical issues such as the system design, size, initial and operating costs, safety, reliability, and serviceability etc. depend very much on the type of refrigerant and compressor selected for a given application. This lesson presents a brief history of refrigerants and compressors. The emphasis here is mainly on vapour compression refrigeration systems, as these are the most commonly used systems, and also refrigerants and compressors play a critical role here. The other popular type of refrigeration system, namely the vapour absorption type has seen fewer changes in terms of refrigerant development, and relatively less number of problems exist in these systems as far as the refrigerants are concerned.
Version 1 ME, IIT Kharagpur
2.2. Refrigerant development – a brief history
In general a refrigerant may be defined as “any body or substance that acts as a cooling medium by extracting heat from another body or substance”. Under this general definition, many bodies or substances may be called as refrigerants, e.g. ice, cold water, cold air etc. In closed cycle vapour compression, absorption systems, air cycle refrigeration systems the refrigerant is a working fluid that undergoes cyclic changes. In a thermoelectric system the current carrying electrons may be treated as a refrigerant. However, normally by refrigerants we mean the working fluids that undergo condensation and evaporation as in compression and absorption systems. The history that we are talking about essentially refers to these substances. Since these substances have to evaporate and condense at required temperatures (which may broadly lie in the range of –100oC to +100oC) at reasonable pressures, they have to be essentially volatile. Hence, the development of refrigerants started with the search for suitable, volatile substances. Historically the development of these refrigerants can be divided into three distinct phases, namely: i. ii. iii. Refrigerants prior to the development of CFCs The synthetic fluorocarbon (FC) based refrigerants Refrigerants in the aftermath of...