{"title":"过热条件下喷嘴出口温度对过热蒸汽射流冷凝特性的影响","authors":"Thanh Dat Phan, Weon Gyu Shin","doi":"10.1016/j.icheatmasstransfer.2024.107640","DOIUrl":null,"url":null,"abstract":"<div><p>During a severe power plant accident, steam condensation mitigates containment pressurization in a postulated nuclear accident. Understanding the condensation process of the steam jet is essential to prevent structural damage and accidents. This study investigated the effect of temperature at the nozzle exit under superheated conditions on the steam jet velocity and temperature distribution, and the condensation characteristics of the steam jet released from the orifice nozzle. The steam jet discharged from the orifice nozzle exhibited the vena-contracta effect, resulting in an increase in velocity along the centerline and a decrease from the exit to the near field. In experiments, the temperature of the exit nozzle was adjusted to 100.4 °C, 106.3 °C, and 112 °C, sequentially. It was found that as the steam jet moves downstream, it undergoes condensation as it mixes with the surrounding air. As the temperature at the exit becomes lower, the condensation becomes more significant, resulting in smaller temperature and velocity spread rates, and larger Liquid Water Content (<em>LWC</em>) and Total Number Concentration (<em>TNC</em>) values, due to the condensation process.</p></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":6.4000,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The effect of temperature at the nozzle exit under superheated condition on the condensation characteristics of a superheated steam jet\",\"authors\":\"Thanh Dat Phan, Weon Gyu Shin\",\"doi\":\"10.1016/j.icheatmasstransfer.2024.107640\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>During a severe power plant accident, steam condensation mitigates containment pressurization in a postulated nuclear accident. Understanding the condensation process of the steam jet is essential to prevent structural damage and accidents. This study investigated the effect of temperature at the nozzle exit under superheated conditions on the steam jet velocity and temperature distribution, and the condensation characteristics of the steam jet released from the orifice nozzle. The steam jet discharged from the orifice nozzle exhibited the vena-contracta effect, resulting in an increase in velocity along the centerline and a decrease from the exit to the near field. In experiments, the temperature of the exit nozzle was adjusted to 100.4 °C, 106.3 °C, and 112 °C, sequentially. It was found that as the steam jet moves downstream, it undergoes condensation as it mixes with the surrounding air. As the temperature at the exit becomes lower, the condensation becomes more significant, resulting in smaller temperature and velocity spread rates, and larger Liquid Water Content (<em>LWC</em>) and Total Number Concentration (<em>TNC</em>) values, due to the condensation process.</p></div>\",\"PeriodicalId\":332,\"journal\":{\"name\":\"International Communications in Heat and Mass Transfer\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":6.4000,\"publicationDate\":\"2024-06-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Communications in Heat and Mass Transfer\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0735193324004020\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MECHANICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Communications in Heat and Mass Transfer","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0735193324004020","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0
摘要
在严重的发电厂事故中,蒸汽冷凝会减轻假定核事故中安全壳的压力。了解蒸汽射流的冷凝过程对于防止结构损坏和事故至关重要。本研究探讨了过热条件下喷嘴出口温度对蒸汽射流速度和温度分布的影响,以及孔板喷嘴释放的蒸汽射流的冷凝特性。从孔板喷嘴排出的蒸汽射流表现出静脉收缩效应,导致沿中心线的速度增加,而从出口到近场的速度降低。在实验中,出口喷嘴的温度依次调整为 100.4 °C、106.3 °C 和 112 °C。实验发现,当蒸汽射流向下游移动时,与周围空气混合会产生冷凝现象。随着出口处温度的降低,冷凝现象会变得更加明显,从而导致温度和速度扩散率降低,液态水含量(LWC)和总数量浓度(TNC)值增大。
The effect of temperature at the nozzle exit under superheated condition on the condensation characteristics of a superheated steam jet
During a severe power plant accident, steam condensation mitigates containment pressurization in a postulated nuclear accident. Understanding the condensation process of the steam jet is essential to prevent structural damage and accidents. This study investigated the effect of temperature at the nozzle exit under superheated conditions on the steam jet velocity and temperature distribution, and the condensation characteristics of the steam jet released from the orifice nozzle. The steam jet discharged from the orifice nozzle exhibited the vena-contracta effect, resulting in an increase in velocity along the centerline and a decrease from the exit to the near field. In experiments, the temperature of the exit nozzle was adjusted to 100.4 °C, 106.3 °C, and 112 °C, sequentially. It was found that as the steam jet moves downstream, it undergoes condensation as it mixes with the surrounding air. As the temperature at the exit becomes lower, the condensation becomes more significant, resulting in smaller temperature and velocity spread rates, and larger Liquid Water Content (LWC) and Total Number Concentration (TNC) values, due to the condensation process.
期刊介绍:
International Communications in Heat and Mass Transfer serves as a world forum for the rapid dissemination of new ideas, new measurement techniques, preliminary findings of ongoing investigations, discussions, and criticisms in the field of heat and mass transfer. Two types of manuscript will be considered for publication: communications (short reports of new work or discussions of work which has already been published) and summaries (abstracts of reports, theses or manuscripts which are too long for publication in full). Together with its companion publication, International Journal of Heat and Mass Transfer, with which it shares the same Board of Editors, this journal is read by research workers and engineers throughout the world.