A Case Study of a Low Power Vapour Adsorption Refrigeration System

Dew point cooling (DPC) is a novel indirect evaporative cooling concept capable of delivering air temperatures approaching the dew point. Coupling this technology with CO2 refrigeration is well suited to minimising transcritical operation when the coefficient of performance (COP) is dramatically reduced in hot climates. A substantial experimental program was conducted to characterise this combination by testing a 20 kW CO2 refrigeration system subject to ambient temperatures above 40 °C. It was demonstrated that DPC operation not only avoided transcritical operation during such weather conditions, but also increased the COP by up to 140% compared to the conventional system. The combination of these technologies was successfully mathematically modelled, from which the optimum condenser inlet air temperature was identified for each condenser temperature. Using this optimum condition, it was possible to maximise the COP for a range of conditions applicable to the psychometric chart. An annual case study for Adelaide, Australia was conducted which demonstrated that optimally coupling DPC with CO2 refrigeration can reduce the annual energy consumption and peak demand by 16% and 47%, respectively, compared to a conventional CO2 booster system. Furthermore, the number of hours of transcritical operation was reduced from 3278 to 27.

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Review of Technology Used to Improve Heat and Mass Transfer Characteristics of Adsorption Refrigeration System

International Journal of Air-Conditioning and Refrigeration ◽

10.1142/s2010132516300032 ◽

2016 ◽

Vol 24 (02) ◽

pp. 1630003 ◽

Cited By ~ 8

Author(s):

Anirban Sur ◽

Randip K. Das

Keyword(s):

Mass Transfer ◽

Heat And Mass Transfer ◽

Waste Heat ◽

Transfer Characteristic ◽

Low Grade ◽

Transfer Performance ◽

Refrigeration System ◽

Adsorption Refrigeration ◽

System A ◽

Absorption Refrigeration System

Researchers proved that, heat powered adsorption refrigeration technology is very effective methods for reutilization of low-grade thermal energy such as industrial waste heat, solar energy, and exhaust gases from engines. But to make it commercially competitive with the well-known vapor compression and absorption refrigeration system, the processes require high rates of heat and mass transfer characteristic between adsorbate and adsorbent as well as externally supplied heat exchanging fluid. This paper reviews various techniques that have been developed and applied to enhance the heat transfer and mass transfer in adsorber beds, and also discuss their effects of the performance on adsorption system. A comprehensive literature review has been conducted and it was concluded that this technology, although attractive, has limitations regarding its heat and mass transfer performance that seem difficult to overcome. Therefore, more researches are required to improve heat and mass transfer performance and sustainability of basic adsorption cycles.

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