Coefficient of performance prediction by a polynomial of a heat transformer with two-duplex components

Polynomial models were developed to predict the coefficient of performance of a heat transformer with a new compact design consisting of a generator-condenser and an absorber-evaporator with a heat load of 2 kW. The operational coefficients of performance ranged from 0.100 to 0.369. Temperature, pressure and concentration of a water lithium bromide solution were measured at different points of the inlet and outlet streams of the main components of the heat transformer. In order to build four polynomial models we calculated a correlation matrix and selected the best independent variables. The best polynomial model included inlet temperature in the generator, absorber-generator, and evaporator; output temperature in the absorber-generator, and pressure in the generator. The developed models showed an excellent correlation between experimental and simulated values of the coefficient of performance with a coefficient of determination R2⩾0.9910.