Investigations of heat and mass transfer of new working fluid systems in absorption heat pumps
Part I of this report investigates selected working fluid pairs with reference to their thermophysical properties, while Part II gives the results of COP-tests of a heat pump, using the ternary working mixture NH(3)-LiNO(3)/H(2)O. The working fluid pairs considered are mixtures of hexafluoroisopropanole (HFIP) as refrigerant with DMPU, NMF, DTG, Sul and 3MSul as solvents, as well as trifluoroethanole (TFE) as refrigerant with NMC and DMPU as solvents. The disadvantages of TFE are its toxicity and the small difference in boiling points between it and its solvents, making rectification necessary. HFIP exhibits boiling point differences well in excess of 200 K to most of its solvents, thus avoiding the need for rectification. Furthermore, HFIP is of only minor toxicity and cannot be classified as ozone-depleting. Its relatively high temperature of solidification of -4 C limits its application in refrigeration and heat pump cycles, but it seems well suited for use in heat transformation. Part II gives the results of investigations on the high pressure working fluid system NH(3)-LiNO(3)/H(2)O, working in an experimental heat pump cycle under realistic conditions. The influence of NH(3)-LiNO(3)/H(2)O) on the parameters of the heat pump cycle, and especially on the coefficient of performance (COP) of the heat pump, was investigated. Marked improvements of the COP were observed, especially in the range of low heat source temperatures.
Bibliographic Reference: EUR 12836 DE (1990) 250 pp., MF, ECU 12, blow-up copy ECU 31.25
Record Number: 199110065 / Last updated on: 1994-12-02
Original language: de
Available languages: de