Solar Water Heating System with Absorption Heat Transformer for Annual Continuous Water Heating

Abstract

We show the performance of solar heating by coupling a Solar Water Heating System (SWHS) with an Absorption Heat Transformer (AHT) for annual continuous water heating. Solar Fraction (SF), Solar Heat Gain (SHG), and Auxiliary Heat (Qaux) were meticulously assessed for three Mexican cities located in the most characteristic climates (Saltillo, Toluca, and Tapachula). This rigorous assessment process ensures the reliability and accuracy of our findings. The potential reduction in net solar collector area (Ac) and storage tank volume (Vt) can be seen by comparing its annual performance to that of a conventional SWHS. Both configurations were designed to deliver the same hot water amount (0.019 kg/s, 1693.4 L/day, heating from 15.8 to 94.4 °C) and simulated using TRNSYS software version 16.01 concerning combinational systems. The results showed that SWHS-AHT achieved superior performance in solar water heating, achieving a higher SF (up to 99.6%) and SHG (up to 1352 kWh/m2-year) compared to the conventional SWHS. On the other hand, the SWHS-AHT achieved similar performance to a conventional SWHS with up to 60% less Ac. For instance, in Tapachula, a SWHS-AHT with an Ac of 150 m2 and a Vt of 18 m3 matched the performance of a SWHS with an Ac of 375 m2 and a Vt of 15 m3. Notably, both systems required the same Qaux. Thus, the Qaux requirement shows that SWHS-AHT is promising for industrial applications in Mexico, offering improved performance and a reduced footprint.