ALTERNATIVE REFRIGERATION CYCLES FOR AUTOMOTIVE AIR CONDITIONING

Abstract

According to convention as mandated by Clean Air Acts, it is anticipated that by 2000 A.D the production of all chloroflurocarbon (CFC) containing/related compounds is to cease. One industry affected by this involves Automotive Air conditioning in which the refrigerant R-12 is used in the vapour compression cycle. The research detailed in this thesis shows the possibility of using an alternative refrigeration cycle instead of a modified refrigerant for the current vapour compression cycle. Two such cycles apart from those already proposed, are The Adsorption Cycle and The Air Cycle. Considering that the current mobile air conditioning unit can provide a cooling capacity of 3.0 Kw [3] whilst operating with a Coefficient of Performance (COP) of 2.09 and weigh approximately 10-15 kg [18] then the alternative cycles should also operate with equivalent levels of performance and size and weight dimensions. Using an approximate computer program to simulate the performance of each cycle, and depending on the specifications for each cycle, operation can theoretically be maintained for the same duty 3.0 Kw, with a C.O.P of between 0.3-1.1 and 2.0-6.0 for a weight in the range estimated between 8.0-25.0 kg for the adsorption cycle and the air cycle respectively. A comparative study of the alternative cycles reveals that the air cycle has the more simplistic design, is lightweight and compact and gives the best operating performance. Although this study is theoretical, this work combined with further study and experimentation shows that both cycles could be built and tested for their future application to automotive air conditioning. Failing this, their use could be extended to other applications involving refrigeration.