Improved efficiency of energy use of a heat transformer using a water purification system

One application of a heat transformer consists in obtaining purified water through single effect evaporation. A fraction of the obtained heat in the absorber can be recycled to only one component of heat source (either in the generator or in the evaporator) to improve efficiency of energy use of the equipment itself. This paper shows the results obtained with a thermodynamic simulator, using lithium bromide-water as working solution at different operation conditions in a 700 W experimental heat transformer. The behavior of Enthalpy Coefficient of Performance is presented as a function of the absorber temperature under different performance conditions in the generator and evaporator. The coefficients of performance are compared to various increases in the temperature of heat source by applying heat recycling to only one component and both components. Under the same performance conditions, when the heat recycling is applied to the generator, the coefficient of performance results in a 110.3% increase, while applied to the evaporator, it results in a 61.5% increase and 79.3% when it is recycling in both components. (C) 2010 Elsevier B.V. All rights reserved.