A thermodynamic analysis of a single-stage vapour absorption refrigeration system operating with a transfer tank is presented with R22-DMF as working fluid. The effects of generator, condenser and evaporator temperatures on performance parameters such as circulation ratio, percentage of generated vapour consumed by transfer tank and coefficient of performance are presented. Also, its performance is compared with the conventional continuous absorption refrigeration system. The transfer-tank-operated system may be preferred when the difference between condenser and evaporator temperatures is less than about 25°C. © 1994.

A Mani

Department of Mechanical Engineering

G. Karthikeyan

Condensers (liquefiers)

Evaporators

performance

Systems analysis

Tanks (containers)

Thermal effects

Thermodynamics

SOLAR OPERATED VAPOR ABSORPTION REFRIGERATION SYSTEM (VARS)

TRANSFER TANKS

Solar refrigeration

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

Analysis of an absorption refrigeration system with transfer tank

Renewable Energy

Experimental investigations have been carried out to study heat and mass transfer characteristics of Tetrafluoro ethane (R134a) in Dimethyl formamide (DMF) solution in a compact bubble absorber of vapour absorption refrigeration system of 1 TR capacity. Plate heat exchangers have been used as system components. Bubble absorption principle is employed in the absorber and hot water supplies heat to the generator. Effect of operating parameters such as circulation ratio, absorber and generator temperatures on heat and mass transfer effectiveness, overall heat transfer coefficient and volumetric mass transfer coefficient are investigated. It is found that heat and mass transfer effectiveness of absorber are better at lower circulation ratios and higher generator temperatures. Experimental results are compared with those obtained from numerical model developed earlier by the authors and the agreement is generally fair. From the experimental data, a correlation has been obtained for volumetric mass transfer coefficient, using multi-linear regression analysis. © 2012 Elsevier Ltd and IIR. All rights reserved.

International Journal of Refrigeration

Heat and mass transfer studies on a compact bubble absorber in R134a-DMF solution based vapour absorption refrigeration system

A vapour absorption refrigeration system (VARS) in which a transfer tank replaces the conventional solution pump is analysed. Six fluid pairs with R22 as the refrigerant and different absorbents: DMA; DMF; DMETEG; DMETrEG; DMEDEG; and NMP are considered. Variations in COP, circulation ratio, percent mass of generated vapour utilised for transfer-tank operation, and minimum generator temperature are compared over a wide range of operating conditions. In general, R22-DMA, R22-DMF, and R22-DMETrEG are preferable for a transfer-tank operated VARS. At high generator temperatures or low condenser temperatures, R22-DMA gives the best overall performance. When the temperatures of the evaporator, absorber, and condenser are high, one may prefer R22-DMF as the working fluid. © 1995.

Performance of different working fluids in transfer-tank operated vapour absorption refrigeration systems

P-T-X data for nine combinations of R22-absorbent solutions are presented as correlations. A comparative study of these working fluids in absorption refrigeration systems is made. Based on cut-off temperature and circulation ratio considerations DMEDEG, DMETEG, DMETrEG, DMF and DMA are preferable solvents for R22. Among these R22-DMF and R22-DMA stand out when the criterion of coefficient of performance is also included. The generator cut-off temperatures are correlated in terms of temperatures of absorber, condenser and evaporator. © 1993.

Comparison of R22-absorbent pairs for absorption cooling based on P-T-X data

Journal	Renewable Energy
ISSN	09601481
Open Access	No