Speaker
Description
This study is performed to investigate the effect of the freezing phenomena in cryogenic liquid hydrogen vaporizer experimentally and theoretically. Whenever cryogenic fluid is used as the working fluid for heat exchanger, heat exchanger is exposed to the risk of freezing due to low temperature profile inside heat exchanger. To avoid the freezing phenomena inside heat exchanger, the flow and thermal characteristics of heat exchanger should be figured out. Generally it is well known that a printed heat exchanger (PCHE) is one of the most popular solution for cryogenic liquid hydrogen vaporizer. Hence, the purpose of this study is to experimentally investigate the flow and thermal characteristics of a printed circuit heat exchanger (PCHE) for cryogenic liquid hydrogen vaporizers. Also, this study is conducted to identify the conditions under when freezing occurs and to present guidelines to avoid freezing when using PCHE. To conduct laboratory-scale PCHE experiments prior to using liquid hydrogen, liquid nitrogen is used as the working fluid in cold channel. Laboratory-scale PCHES are designed and fabricated using diffusion bonding. Glycol water is used as the working fluid in hot channels for exchanging heat between the cold and hot channels. To determine the freezing conditions in PCHE, the heat transfer performance of laboratory-scale PCHE and the pressure drop in the hot channel is investigated. Furthermore, relatively large deviations in thermo-physical properties are taken into account to evaluate heat transfer coefficient and freezing conditions inside PCHEs. The results of this study may shine light to suggest a guideline about avoiding freezing problems in PCHE.
| Submitters Country | Republic of Korea |
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