Miniaturisation of the vapour absorption refrigerator requires replacement of the solution pump by a heat operated bubble pump and air cooled condenser and absorber. The replacement necessitates the selection of working media restricted to vacuum operation, and the air cooling poses the problem of high pressure drops in the refrigerator. Thermodynamic analysis of the absorption refrigerator with such a suitable working medium is performed considering the pressure drops in the system as parameters. The analysis shows that the effect of the evaporator to absorber pressure drop on the system performance is more significant than that of the generator to condenser pressure drop, and it becomes more predominant at the low generator temperature normally encountered in solar operated systems. © 1997 Elsevier Science Ltd.

M. Prakash Maiya

Department of Mechanical Engineering

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Effect of component pressure drops in two-fluid pumpless continuous vapour absorption refrigerator

Energy Conversion and Management

Experimental analysis of a H2O-LiBr vapour absorption cooler based on bubble pump technique and hydrostatic principle are presented. Heat input to the bubble pump and boiler, pump lift/driving head and weak solution concentration are varied to analyze the system performance. The cooler is tested at different load conditions, i.e., at no load, pull down load and steady load conditions. Results indicate that coefficient of performance of about 0.50 could be attained for the boiler temperature of 85 °C and condenser and absorber temperatures in excess of 40 °C. © 2003 Elsevier Ltd. All rights reserved.

Applied Thermal Engineering

Experimental analysis of a bubble pump operated H2O-LiBr vapour absorption cooler

The hydrostatic principle and bubble pump technique are used in the two-fluid pumpless continuous vapour absorption refrigerator to create the circulations of the solution and refrigerant. In this paper, the bubble pump, which is the 'heart' of this natural circulation type of refrigerator, has been investigated both analytically and experimentally. The bubble pump is modelled for intermittent slug flow of solution and vapour mixture. A test rig is built in glass to evaluate the performance of the bubble pump, to visualize the flow behavior and to validate the analytical model. Bubble pump tube diameter, pump lift, driving head and heat input are varied to analyze the pump performance. Results indicate that pumping ratio is nearly independent of the heat input, but increases with decrease in pump tube diameter, decrease in pump lift and increase in driving head. © 1998 Elsevier Science Ltd and IIR. All rights reserved.

Journal	Data powered by TypesetEnergy Conversion and Management
Publisher	Data powered by TypesetElsevier Ltd
ISSN	01968904
Open Access	No