Dynamic simulation of an aqua-ammonia absorption cooling system with refrigerant storage

Dynamics and control of solar thermochemical reactors

“…At steady state, Á ss = j (n * out y j,out − n * in y j,in )| 0 h j (T R ) Q * solar (10) The relative difference between the overall and steady-state efficiency at the end of the day is: Fig. 7 shows the variation of the solar-to-chemical energy conversion efficiency during 3 simulated solar runs: (a) idealized sunny day, (b) real sunny day, and (c) partly cloudy day, for both solar reac- tors (left: reactor 1 for the carbothermic reduction of ZnO; right: reactor 2 for the steam-gasification of petcoke).…”

“…Thus, their dynamic behavior is critical for efficient and safe operation. Previous studies on dynamics and control of solar thermal systems include flat plate solar collectors [2][3][4][5][6][7], solar heating [8], solar air conditioning and refrigeration [9][10][11], solar heating in space applications [12], solar steam generation [13][14][15][16][17], solar furnace operation [18], and solar thermal power plants [19,20]. Widely used is the software package TRN-SYS, which allows for dynamic simulation of conventional solar components and systems, but cannot handle solar thermochemical processes that involved coupled mass/heat transport of reactive flows.…”

Comparison the start-up time of the key parameters of aqua-ammonia and water–lithium bromide absorption chiller (AC) under different heat exchanger configurations

“…Investigation the behavior of the absorption cycle in dynamic mode by applying the step change in the cycle [5,6,8,12,13] and during start-up [7,14,15] have been already carried out. Dynamic simulation of ammonia-water heat pump [8,[16][17][18][19] was accomplished to predict the transient performance and design characteristics as well.…”

State of the Art of Solar Absorption Cooling Technologies

“…lumped and distributed parameter models, and pointed out that most of the works were based on lumped parameter models with two exceptions (Butz and Stephan, [42]; Sano et al, [43]). Some other works not mentioned in Zhuo [37] included modeling of a periodically operating ammonia-water heat pump by Jeong, [44], a solar ammonia-water absorption cooling system with refrigerant storage by Kaushik et al, [45] and more recent works on hot water-driven LiBr-water absorption heat pump and chillers by Jeong et al, [46]; Bina et al, [47]; Kohlenbach and Ziegler, [48]; Fu et al, [49]. Distributed parameter model such as Butz and Stephan [50] required excessive computing time for the time scale to be simulated in the present study.…”