Performance study of a novel two-bed thermochemical cooling system forlow temperature application: Modelling and Validation .

Conventional vapor compression systems require significant electrical energy to achieve low evaporator temperatures,
which limits their application in low-resource or off-grid scenarios. Sorption-based cooling systems
offer a promising alternative by utilizing low-grade thermal energy, reducing dependency on electricity. This
study investigates a two-bed thermochemical sorption system to overcome the inherent trade-off in single-bed
systems, where achieving low evaporator temperatures typically demands high regeneration temperatures.
Four high temperature salt (HTS) and medium temperature salt (MTS) pairs, MnCl2-SrCl2, MnCl2–CaCl2, MgCl2-
SrCl2, and MgCl2–CaCl2 were selected using thermodynamic and kinetic data. Performance of these pairs with
optimised two tube-bundle reactor configuration is evaluated using a transient numerical model. The two-bed
system achieved evaporator temperatures down to -30 ◦C with regeneration temperatures as low as 130 ◦C.
MnCl2-SrCl2 showed the highest overall performance of specific cooling power of 57 W/kg, cooling capacity of
854 W and coefficient of performance of 0.14, while MgCl2 pairs performance is low due to its slow kinetics.
Overall, analysis revealed that limiting system operation to 70 % of the maximum sorption capacity improves
energy efficiency by maintaining faster reaction rates.