Working pairs for resorption refrigerator

The performances of three chemisorption working pairs operating under the resorption cycle were studied gravimetrically by comparing the desorbed and adsorbed mass of refrigerant in different operation conditions. All pairs used NH 3 as refrigerant and MnCl 2 in the main reactor, but each one used a different salt for the cooling effect production in the secondary reactor. These salts were NH 4Cl or NaBr or BaCl 2. The experimental results indicated that the degree of conversion in reaction between the NH 3 and BaCl 2 was inferior to 25% during cooling production at 0 °C or below, whereas the reactions with the other salts had conversions of at least 80%. When the systems operated with heat source temperature for the main reactor at 155 °C, heat sink temperature for both reactors at 30 °C, and cooling effect production temperature at 0 °C the coefficient of performance (COP) of the system using NH 4Cl and the system using NaBr were similar and around 0.30; however, the former system had a specific cooling power (SCP) 5% higher than that of the latter system. Because the reaction in the system with NH 4Cl was practically halted in a period much shorter than that used in the experiments, it is possible to expect that if the period of the cooling period was shortened, the difference between the SCP of those systems would be much higher. ► The comparison of three different working pairs operating under resorption cycle was conducted. ► The three working pairs were NH 4Cl/MnCl 2, NaBr/MnCl 2, BaCl 2/MnCl 2, respectively. ► The mass of refrigerant reacted in different situations were measured and compared. ► Among the LTS studied, NH 4Cl is the most suitable to be used in a resorption machine at 0 or below 0 °C.