Effects of different adsorber bed designs on in-situ water uptake rate measurements of AQSOA FAM-Z02 for vehicle air conditioning applications

Adsorption cooling systems (ACS) utilize waste heat to produce the cooling power required for air conditioning (A/C) in vehicles. In addition to having an adsorbent with high adsorbate uptake rate and thermal conductivity, different adsorber bed designs can significantly affect the performance of an ACS. In this study, the water uptake rate of AQSOA FAM-Z02 packed in two different adsorber beds is measured in-situ under adsorption and desorption temperatures of 30 and 90 °C, and the water vapor supplied at 20 °C. The effects of some parameters, such as changes in the density of heat transfer fluid and stiffness of flexible hosing connected to the adsorber bed, show significant contribution in the adsorbate uptake mass measurements. To de-convolute these undesirable effects, a two-step mass measurement is performed to precisely measure the adsorbate uptake rate. To verify the developed method, the equilibrium water uptakes of AQSOA FAM-Z02 are measured and compared against the available data in the literature measured by a thermogravimetric analysis. Next, the water uptake of AQSOA FAM-Z02 is measured for different cycle times, followed by calculation of specific cooling power (SCP) and coefficient of performance (COP). Results show that high heat transfer surface area and small fin spacing are the main specifications of a well-designed adsorber bed for ACS applications. As a result of using AQSOA FAM-Z02 and a well-designed adsorber bed, a SCP of 112.9 W/kg and a COP of 0.34 are achieved at cycle time of 10 min.