22 May 2002

B4-15 Thermodynamic evaluation of different heat pump variations for water purification

As an alternative method for water purification researchers are intending the use of heat pumps. The absorption heat pumps turn in to be an attractive option to use low temperature energy and by means of a thermodynamic cycle rise it to high temperature energy. It can be possible by means of the circulation of a secondary circuit of diluted and concentrated solutions of a working pair formed by lithium bromide / water or Carrol / water solutions.
The use of a single stage absorption heat transformer (SSHT) has been proposed and optimised for water purification.
Thermodynamic evaluations of two working pairs are shown, lithium bromide / water and Carrol / water. These evaluations show that it is possible to use waste energy to carry out the water purification in residential areas far from the supply of drinkable water in Mexico.
The thermodynamic efficiency has been calculated for different operation conditions. The coefficient of performance (COP) has been optimised in function of the generation and evaporation temperatures, when the SSHT operates at temperatures near to the ambient temperature.
The results show the operation conditions for both mixtures with the main and dominant environmental conditions in the central region of Mexico with out drinkable water supply.