Study on the start-up characteristics of double-effect absorption refrigerator driven by waste steam

Absorption refrigerators can be driven by waste heat. In particular, the double-effect type of absorption refrigerator, which is highly efficient, is drawing a great deal of attention as a waste heat recovery system. This research examines the double-effect absorption refrigerator driven by steam, assuming waste heat from the fuel cells is applied. In the start-up of the double-effect absorption refrigerator, the solution temperature is almost equal to the temperature of the air. Due to the large temperature difference between the solution and the heat sources, the solution is overheated. In the worst case, it will be crystallized. Additionally, some solution is circulated due to the existence of a pressure difference between the heat exchangers. If the solution pump is started before an adequate pressure difference is obtained, the absorption refrigerator cannot be started normally. To investigate these problems, a simulation model is constructed. An experiment is conducted to investigate the performance of this model. As a result, the validity of this model is confirmed and the detailed start-up characteristics are clarified. (C) 2000 Scripta Technica, Heat Trans Asian Res, 29(5): 427-445, 2000.