M.A.R. Eisa

Thermodynamic design data for absorption heat transformers—Part II. Operating on water-calcium chloride

Abstract The Gibbs phase rule and the thermodynamic properties of the working pair limit the choice of operating temperatures. For any combination of the temperatures, the concentrations in the absorber and the generator and hence the flow ratio are fixed. For any particular working pair, the coefficient of performance is related to the flow ratio. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for absorption heat transformers operating on water-lithium bromide. The interaction of operating temperatures has been illustrated graphically.

Thermodynamic design data for absorption heat pump systems operating on water-lithium bromide part II: Heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy-based coefficients of performance, have been presented for water-lithium bromide absorption systems for heating. The interactions of operating temperatures have been illustrated graphically.

Thermodynamic design data for absorption heat pump systems operating on water-lithium chloride—Part one. Cooling

Abstract The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. For a given combination of temperatures, the concentrations in the absorber and the generator are fixed automatically. This determines the flow ratio. Therefore for any particular working pair, the coefficient of performance is related to the flow ratio. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalphy based coefficients of performance have been presented for a water-lithium chloride absorption system for cooling. The interaction of operating temperatures has been illustrated graphically. The data obtained are also compared with published data for the water-lithium bromide absorption system under identical conditions.

Thermodynamic design data for absorption heat transformers—III. Operating on ammonia-water

Abstract The Gibbs phase rule and the thermodynamic properties of the working pair limit the choice of operating temperatures. For any combination of temperatures, the concentrations in the absorber and the generator and hence the flow ratios are fixed. For any particular working pair, the coefficient of performance is related to the flow ratio. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for absorption heat transformers operating on ammonia-water. The interaction of operating temperatures has been illustrated graphically.

Thermodynamic design data for absorption heat pump systems operating on ammonia—water—Part II. Heating

Abstract The free choice of operating temperature in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia—water absorption systems for cooling. The interaction of operating temperatures have been illustrated graphically.

Experimental studies to determine the effect of differences in absorber and condenser temperatures on the performance of a water-lithium bromide absorption cooler

Abstract Experiments have been carried out on a water-lithium bromide absorption cooler to determine the effect on performance of operating the absorber and condenser at different temperatures. The absorber temperature TAB was varied between 33.0 and 43.1°C and the condenser temperature TCO between 33.0 and 50.0°C. The experiments show that, as the temperature difference (TAB−TCO) is increased, the coefficient of performance and the cooling capacity are decreased.

A study of the operating characteristics of a water-lithium bromide absroption heat pump

Abstract Performance data have been obtained on an experimental water-lithium bromade absorption heat pump constructed largely from standard glass components for three concentrations of lithium bromide. The experiments which were carried out for a delivery temperature of 70°C, show that the coefficient of performance decreases and the temperature lift increases with an increase in flow ratio and an increase in the concentration of lithium bromide. Coefficients of performance of between 80 and 90 per cent of the theoretical maximum possible values were obtained.

Working fluids for high temperature heat pumps

Abstract The suitability of working fluids for use in high temperature heat pump systems has been considered on the basis of their volumetric and other thremodynamic properties. The change of thermodynamic properties with temperature has been graphically illustrated. It is shwon that water becomes increasingly attractive as a working fluid as the delivery temperature approaches 200°C. A heat pump using water as the fluid is capable of an actual coefficient of performance of five and a gross temperature lift of 70°C for a condensation temperature of 200°C.

Experimental evaluation of aqueous lithium halides as single- and double-salt systems in absorption heat-pumps

Performance data have been obtained on a small glass absorption heat-pump operating with water as a working fluid in combination with both single- and double-salt solutions as the absorbent. The salts were lithium chloride, lithium bromide, lithium iodide and mixtures of lithium chloride and lithium bromide, and lithium chloride and lithium iodide. The experiments were carried out with a delivery temperature of 70°C and an initial generator temperature of about 100°C. The performance data have been discussed for single- and double-salt systems in the light of the physical and thermodynamic properties of these systems.

Classified references for absorption heat pump systems from 1975 to May 1985

Abstract More than four hundred references for absorption heat pump systems have been listed and classified on the basis of heating cooling and heat storage. They been further classified on the basis of water-lithium bromide, ammonia-water and other systems.