He, J, Miao, J, Bai, L orcid.org/0000-0001-9016-1569 et al. (3 more authors) (2017) Effect of non-condensable gas on the startup of a loop heat pipe. Applied Thermal Engineering, 111. pp. 1507-1516. ISSN 1359-4311
Abstract
It is essential to address the startup issues prior to the wide application of loop heat pipes (LHPs) in both space and terrestrial surroundings. As non-condensable gas (NCG) is an important factor affecting the startup behavior, its effects on the startup performance of an ammonia-stainless steel LHP with and without preconditioning were experimentally investigated in this work. Nitrogen with controlled amounts was used to simulate the NCG, and the temperature overshoot, liquid superheat and startup time were employed as the evaluation criteria. Four situations relating to initial liquid/vapor distribution in the evaporator were examined: (1) both evaporator core and vapor grooves are filled with liquid, (2) vapor exists in vapor grooves and the evaporator core is filled by liquid, (3) vapor grooves are filled by liquid and vapor exists in the evaporator core, and (4) vapor exists in both evaporator core and vapor grooves. Experimental results showed that with NCG presence in the LHP, the startup could only proceed in situation 1 with preconditioning, while it could proceed in situations 1, 3 or 4 without preconditioning. For the startup in situation 1, a larger NCG inventory led to much degraded startup performance, and a higher startup heat load could benefit the startup. For the startup in situation 3, the most difficult startup situation, NCG resulted in a very high temperature overshoot, which may even exceed the maximum allowable value. For the startup in situation 4, the existence of NCG in the vapor grooves could facilitate the evaporation there, leading to a very desirable startup.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016, Elsevier Ltd. This is an author produced version of a paper published in Applied Thermal Engineering. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Loop heat pipe; Startup; Experiment; Non-condensable gas; Thermal control |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 Oct 2016 14:58 |
Last Modified: | 25 Jul 2017 16:40 |
Published Version: | https://doi.org/10.1016/j.applthermaleng.2016.07.1... |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.applthermaleng.2016.07.154 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:105976 |