未利用熱エネルギーを活用する低温駆動・低温発生型吸収冷凍機の研究開発

<p>To improve the low-temperature waste heat recovery and its utilization, we proceeded with the development of a low-temperature-driven absorption chiller adopting a double-lift absorption cooling cycle. In the previous reports, we developed a proof-of-concept prototype, and it delivered chilled water at approximately 7 °C when driven by a 60 °C heat source hot water inlet and 30 °C cooling water. We confirmed the reliability of this result from the heat balance of the experimental data, according to the AHRI standard. Cooling capacity in the above conditions was 7.1 kW, which was approx. 1.0 kW smaller than expected. We found approximately 1.31 kW of internal heat loss across the separating plate between the low-temperature evaporator and the low-temperature absorber. The capacity degradation was explained by this internal heat loss clearly. This report examined this cycle’s cooling water temperature characteristics as the next step. We computed the behavior of the prototype when the cooling water varied from 24 °C to 36 °C using a cycle simulator. These results were validated by comparing the calculated results with the experimental data of the prototype. The simulation result agreed with the experiment by ± 5% for the cooling capacity and ±0.01 for the COP. Finally, we predicted the performance of this cycle without the internal heat loss. As a result, we found that cooling capacity increased by 7.9%, and COP improved from 0.32 to 0.36 in approximately 9 °C chilled water output conditions in the case that prevents the internal heat loss.</p>