RESPONSE THE COEFFICIENT OF PERFORMANCE MODELS FOR EVALUATION OF DIFFUSION ABSORPTION REFRIGERATION SYSTEM

Abstract

Three mathematical models were used to determine the coefficient of performance COP of the diffusion absorption refrigeration system DAR. These models give different results of COP because it depends upon various scientific bases. Therefore, in this study used the three models to compare between the values of COP. The first model from viewpoint of temperature thermodynamic ideal cycle, the second model using mass flow rate thermodynamic and the last model employing the cooling capacity of refrigerator. The highest value of COP by (model 1) was 1.26 while the lowest value was 0.77. Model 2 gave 0.671 as highest value and the lowest value was 0.475, respectively. The highest value of COP by (model 3) was 0.155 while the lowest value was 0106. The exponential function behavior showed the relation between the generator temperature (Tg) and the circulation ratio(f) which can be described by the equation f = 629.52e-0.0193Tg, R2 =1.The statistical indicators to select the actual COP indicated to the majority of values for three models by harmonic mean (HM) were 1.118, 0.567 and 0.124, respectively. The study concluded that using second model is the best way to use for judgment of cycle performance because it depend upon the temperatures of refrigeration cycle parts and mass flow rate of working fluids in each part of this cycle.