Absorption heat pumps

The main factor that has been responsible for the slow adoption of absorption heat pumps for heating and air conditioning duties has been their high capital cost compared with that of vapor compression equivalents. This is due largely to the cycle complexity, as shown in Figure 14, which displays the four principal cycle elements, all of which involve vapor-liquid systems ... 

As part of a general development to use spinning discs in an intensified absorption heat pump, Aoune and Ramshaw (16) measured both the local and average heat transfer performance on smooth rotating surfaces. The disc surface... 

Figure 14 Single-effect absorption heat pump cycle.

Ramshaw C, Winnington TL. An intensified absorption heat pump. Proc Inst Refrig... 

Knoche, K. F. and Stehmeier, D., "Exergetlc Criteria for the Development of Absorption Heat Pumps," AIChE National Meeting, Detroit, MI, Aug. (1981). 

BINARY-FLUID HEAT AND MASS TRANSFER IN MICROCHANNEL GEOMETRIES FOR MINIATURIZED THERMALLY ACTIVATED ABSORPTION HEAT PUMPS... 

Gommed, K., and Grossman, G. (1990) Performance Analysis of Staged Absorption Heat Pumps Water-Lithium Bromide Systems, ASHRAE Transactions, Vol. 96(1), pp. 1590 - 1598. 

Garimella, S., Christensen, R. N., and Petty, S. E. (1992) Cycle Description and Performance Simulation of a Gas-Fired Hydronically Coupled Double-Effect Absorption Heat Pump System, Winter Annual Meeting of the American Society of Mechanical Engineers, Anaheim, CA, USA, Vol. 28, ASME, New York, NY, USA, pp. 7-14. 

McGahey, K. R., Garimella, S., Cook, F. B., and Christensen, R. N. (1994) Enhancement of the ORNL Absorption Model and Simulation of a Double-Effect Absorption Heat Pump, Proceedings of the International Absorption Heat Pump Conference, New Orleans, LA, USA, ASME, New York, NY, USA,pp. 141-148. 

Garimella, S., Lacy, D., and Stout, R. E. (1997) Space-Conditioning Using Triple-Effect Absorption Heat Pumps, App/icfi Thermal Engineering, Vol. 17(12), pp. 1183-1197. 

Michel, J. W., and Perez-Bianco, H. (1985) Influence of Surfactant Additive on Absorption Heat Pump Performance, ASHRAE Transactions, Vol. 91, Part 2B, p. 1847. 

Kang, Y. T., Chen, W., and Christensen, R. N. (1997) Generalized Component Design Model by Combined Heat and Mass Transfer Analysis in NH3/H2O Absorption Heat Pump Systems, Proceedings of the 1997ASHRAE Winter Meeting, Jan 26-29 1997, Philadelphia, PA, USA, Vol. 103, ASHRAE, Atlanta, GA, USA, pp. 444-453. 

Uddholm, H., and Setterwall, F. (1988) Model for Dimensioning a Falling Film Absorber in an Absorption Heat Pump, International Journal of Refrigeration, Vol. 11(1), pp. 41-45. 

Binary-Fluid Heat and Mass Transfer in MicroChannel Geometries for Miniaturized Thermally Activated Absorption Heat Pumps 339... 

The nature of boiling heat transfer in a channel with the gap less than the capillary is also studied and presented. The condensation flow mechanisms, pressure drop and heat transfer in microchannels, role of microscale heat transfer in augmentation of nucleate boiling and flow boiling heat transfer, binary-fluid heat and mass transfers in microchannel geometries for miniaturized thermally activated absorption heat pumps, evaporation heat... 

A. Beutler, E. Ziegler, G. Alefeld, International Absorption Heat Pump Conference, Montreal, Canada, 1996, 303-309. 

FIGURE 14.12 Solar dryer for peanuts equipped with absorption heat pump and heat storage. (From Auer, W.W., in Drying 80, A.S. Mujumdar, Ed., Hemisphere, New York, 1980, p. 292.)... 

COPjs jjp Coefficient of performance for the absorption heat pump... 

Various experimental fittings can be adapted on the C 80 calorimeter, especially a vapour absorption device (Fig. 3) which allows to simulate the cycle of an absorption heat pump. 

This operation follows the cycle of an absorption heat pump, which is composed of two vessels under vacuum, separated by a valve (Fig. 11) (5). 

Eurutera M, Origane T, Sawada T, Kunugi Y, Kashiwagi T, Takei T, Aizawa M, Mori H. Advanced absorption heat pump cycles. Proc Inti. Absorption Heat Pump Conf. Montreal, 1996, pp 109-119. 

An NGL plant was selected to analyze several distillation assisted heat pump processes when compared to conventional distillation. The depropanizer column which is the third column of the NGL plant was suitable for retrofitting by heat pump systems. This conventional process, along with top vapour recompression, bottom flashing and absorption heat pumps, were simulated using the Aspen Plus software, in order to determine economically the best alternative. Distillation with both top vapor recompression and bottom flashing heat pumps allows reduction of operation (energy) costs by 83.3% and 84%, respectively. This improves the economic potential (incorporating capital costs) by 53% and 54%, respectively. 

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