Performance of a Novel Steam Generation System Using a Water-zeolite Pair for Effective Use of Waste Heat From the Iron and Steel Making Process

• Published in: ISIJ International 2015/02/15, Vol.55(2), pp.448-456
• Main Authors: Nakaso, Koichi, Tanaka, Yuuki, Eshima, Shotaro, Kobayashi, Shunsuke, Fukai, Jun
• Format: Article
• Language: English
• Subjects: adsorption heat pump; effective use of waste heat; numerical; steam generation
• ISSN: 0915-1559; 1347-5460
• DOI: 10.2355/isijinternational.55.448

To reduce CO2 emission from the iron and steel making process, a novel steam generation system using waste hot water is proposed to use waste heat effectively from the process. This system adopts a direct heat exchange method for the adsorption heat pump to increase the heat transfer rate between the adsorbent and heat transfer fluid. In this study, the performance of the system is evaluated according to the mass of steam generated during the cyclic operation. The regeneration process is first studied taking the transport phenomena in the generator into account. The mass of steam generated is then estimated based on the distributions of water content and temperature in the generator. The results from the model exhibit good agreement with the experimental results. The effect of the operating conditions on the performance of the steam generation process is studied. It was found that there was an appropriate regeneration time to maximize the mass of steam generated during the cycle. For the effective use of adsorption heat, reuse of the water drained from the steam generation process (Drainage Recycling) is proposed. As a result, recycling the drainage water is a practical and helpful method to improve the performance of the system.