Transient simulation of a lithium bromide-water vapour absorption refrigeration system

Jeggels, Dawood (2015-12)

Thesis (MSc)--Stellenbosch University, 2015.

Thesis

ENGLISH ABSTRACT: Vapour absorption is a thermally activated heat pump process that can be used to produce refrigeration. The attraction of this technology is that it can harness low temperature sources of thermal energy to produce a useful output. This is of relevance when considering the possible implementation of this technology as a source of renewable energy as well as a mechanism for waste heat recovery and utilization. In order to work towards a better understanding of this technology this project set the goal to theoretically simulate a vapour absorption system. After evaluation of the possible implementations of this technology the decision was made to investigate a water/lithium-bromide variant of vapour absorption cycles. Through the application of the fundamental principles of conservation a transient simulation was developed for a single effect water/lithium-bromide vapour absorption system. The resulting simulation was used to describe the start up and refrigeration effect of a theoretical vapour absorption system. In particular no transient absorption system simulation work was found in the available published literature. For verification of the developed simulation model, hence, an experimental apparatus was constructed to obtain experimental results for comparison and validation of the developed simulation. When comparing the results obtained from the simulation and the experimental work the difference in temperature values was at most 23%.

AFRIKAANSE OPSOMMING: Dampabsorpsie is 'n termies geaktiveerde hittepompproses wat gebruik kan word om verkoeling te produseer. Die aantreklikheid van hierdie tegnologie is dat dit 'n lae temperatuur bron van hitteenergie kan benut om 'n nuttige uitset te produseer. Veral, kan dit gebruik word as 'n manier vir die herwinning van hernubare energie asook as afvalhitte. Ten einde om 'n beter begrip van hierdie tegnologie te bewerkstellig is die doel van hierdie tesis projek om 'n teoretise simulasie model saam te stel. Na evaluering van die moontlike implementering van hierdie tegnologie is die besluit geneem om 'n water-litiumbromied variant van dampabsorpsie te ondersoek. Deur die toepassing van die fundamentele beginsels van die behoud van massa en energie is 'n oorgangssimulasie model vir 'n enkeleffek waterlitiumbromied dampabsorpsie stelsel ontwikkel. Die resulteerende simulasie is gebruik om die aktivering en verkoelingseffek van 'n teoretiese damp absorpsie stelsel te beskryf. Soortgelyke werk kon nie in die gepubliseerde literatuur gevind word nie. Dus is 'n eksperimentele apparaat gebou om resultate te verkry vir 'n vergelyking met die teoretise simulasie. 'n Vergelyking tussen die temperatuur waardes van die simulasie en die eksperimentele werk wys dat die verskil in temperatuur op die meeste 23% was.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/97949
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