Pressure Losses in the Three-Fluids Absorption Cycle Components, Piping, and its Impacts on Cycle Performance

The global energy crisis has spurred researchers to seek effective alternatives across various fields. There is a high demand for refrigeration and air conditioning for domestic and commercial use, yet these systems consume considerable energy. In hot and humid countries and arid regions, the need for refrigeration is particularly acute, compounded by the availability of electrical energy. Systems based on low-temperature media, waste heat, or solar energy are thus highly sought after. The aqua-ammonia-hydrogen absorption cycle could be a viable alternative to the conventional vapor compression refrigeration cycle in off-grid areas due to its lower capital investment and ease of maintenance. This article concentrates on the thermal modeling of the ammonia-water-hydrogen diffusion absorption refrigeration cycle. The overall efficiency of this three-fluid absorption cycle has been parametrically studied through computer simulations. The study also considers the associated pressure losses in the cycle components, piping, and hydrodynamic pressure to evaluate its actual performance. Detailed analysis reveals a 37.36% decrease in overall cycle performance at generator temperatures below 120°C. However, this performance loss diminishes as the generator temperature increases, with a 23.52% loss noted at 140°C. Additionally, it is pointed out that an optimum ammonia mass fraction between 0.25 and 0.45% is critical for achieving optimal cycle performance.