The evaporator temperature, condenser temperature, C2H6/CO2 mixture condensation temperature, cascade temperature differences, and the CO2 mass fraction are chosen as the decision variables.
The condenser temperature, Tcond, is kept at 623 K.
Some combinations of brine temperature and condenser temperature are also shown to be infeasible.
Changing condenser temperature also changes the capacity of the cooling system.
It is observed that optimum generator temperature decreases with evaporator temperature and increases with condenser temperature.
In the sample application, the thermoeconomic optimization reveals the optimum generator temperature, condenser temperature, absorber temperature, condenser temperature of vapour compression section, effectiveness of solution heat exchanger and compressor isentropic efficiency.
Reducing condenser temperature is shown to improve specific work output up to 47% with diminishing effect as brine temperature increases.
A parametric study is performed by varying inlet air temperature, air-to-fuel ratio, throttling temperature, and condenser temperature.
The latter are defined as the condenser temperature being at the ambient wet bulb temperature or dry bulb temperature, respectively.
The tested condition is set at boiler and condenser temperature of 90°C and 34°C, respectively.
The design conditions were generator temperature 117.7 132.5 °C, condenser temperature 42 50 °C and evaporator temperature −10 5 °C.
