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Clamped plate-style recuperator for a small-scale solar thermal brayton cycle using high-temperature sealant
Dissertation (MSc)--University of Pretoria, 2019.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2020
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| _version_ | 1867613565169434624 |
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| access_status_str | Open Access |
| author2 | Le Roux, Willem G. |
| author_browse | Le Roux, Willem G. |
| author_facet | Le Roux, Willem G. |
| collection | Thesis |
| dc_rights_str_mv | © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc)--University of Pretoria, 2019. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/73467 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:38:09.710Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2020 |
| publishDateRange | 2020 |
| publishDateSort | 2020 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/73467 Clamped plate-style recuperator for a small-scale solar thermal brayton cycle using high-temperature sealant Le Roux, Willem G. u12000826@tuks.co.za Meyer, Josua P. Dellar, Kyle Eric UCTD Small-scale solar Thermal brayton Clamped plate-style recuperator High-temperature sealant Engineering, built environment and information technology theses SDG-07 SDG-07: Affordable and clean energy Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-13 SDG-13: Climate action Dissertation (MSc)--University of Pretoria, 2019. South Africa is plagued by rolling blackouts, and many citizens do not have access to electricity or clean water. A personalised micro-turbine power generation system presents a solution to this issue and may become as commonplace as a personal computer. With South Africa’s excellent solar direct normal irradiation (DNI) levels, a small-scale recuperated solar thermal Brayton cycle (STBC) shows enormous potential. However, a recuperator comprises up to 30% of the capital cost associated with a micro-turbine package and requires complex and costly manufacturing methods within a South African context. Thus, the objective of this research is to investigate a clamped plate-style recuperator that can be cost-effectively manufactured locally. Literature was consulted and criteria were outlined that a recuperator in a Brayton cycle should adhere to. To uphold these requirements, a counterflow plate-style recuperator is mandatory, and to combat complex manufacturing methods, a gasketed stacked-plate design, which requires a gasket material, was proposed. A sodium silicate-based sealant called Soudal Calofer is available locally and can withstand the operating conditions of an STBC. Experimental testing was carried out successfully on two small-scale versions of the proposed recuperator design. Testing showed that the physical construction was simple and cost-effective and the clamped plate-style high-temperature sealant combination worked well to form the recuperator core, facilitating an easy assembly and disassembly process. The construction sustained an airtight seal (Mark I) for the entire testing period at various pressures and high temperatures. Despite the occurrence of heavy soot-based fouling deposits during Test 1 due to incomplete combustion of the LPG as a result of the very low air mass flow rates, a mathematical model was able to match the values gathered from the testing. The data showed a cold-side effectiveness of 58.6% and a total pressure loss of 17.78%. For Test 2, a cold-side effectiveness of 82.5% and a total pressure loss of 11.48% were found for the recuperator core, which also validated the mathematical model. A case study was performed for the small-scale STBC. The results showed that the combination of a cold-side effectiveness of 84% and a total pressure loss of less than 5% could be attained when implementing the recuperator within the STBC for a channel height of 1 mm and width of 50 mm. Alternatively, if pressure loss is of less concern, a cold-side effectiveness of 89% could be achieved by increasing the total pressure loss to 19 kPa, which equates to an 8.8% pressure loss. It is recommended that a large-scale recuperator be built and tested to confirm the performance characteristics of larger mass flow rates and that the insulation of the unit be varied to determine its effects. Gasket geometry and the assembly method also need to be further researched to develop a uniform and consistent assembly technique that results in an airtight seal for every unit assembled. This may be achieved by regulating the amount of water added to the Soudal Calofer for thinning purposes to achieve a consistency which facilitates uniform application and by extended drying time to allow for the assembly to be completed, while not thinning the sealant so much as to lead to a seal failure. In conjunction, the clamping force distribution is critical to sealing the inner channel division. It is also recommended that the usable lifespan of such a recuperator be determined. Most crucially, thermal and pressure cycling must be investigated, especially where seal integrity is concerned. mi2025 Mechanical and Aeronautical Engineering MSc Unrestricted SDG-07: Affordable and clean energy SDG-09: Industry, innovation and infrastructure SDG-13: Climate action 2020-02-21T07:24:11Z 2020-02-21T07:24:11Z 2020-04-14 2019 Thesis Dellar, KE 2019, Clamped plate-style recuperator for a small-scale solar thermal brayton cycle using high-temperature sealant, MSc Thesis, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/73467> A2020 http://hdl.handle.net/2263/73467 en © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Small-scale solar Thermal brayton Clamped plate-style recuperator High-temperature sealant Engineering, built environment and information technology theses SDG-07 SDG-07: Affordable and clean energy Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-13 SDG-13: Climate action Clamped plate-style recuperator for a small-scale solar thermal brayton cycle using high-temperature sealant |
| title | Clamped plate-style recuperator for a small-scale solar thermal brayton cycle using high-temperature sealant |
| title_full | Clamped plate-style recuperator for a small-scale solar thermal brayton cycle using high-temperature sealant |
| title_fullStr | Clamped plate-style recuperator for a small-scale solar thermal brayton cycle using high-temperature sealant |
| title_full_unstemmed | Clamped plate-style recuperator for a small-scale solar thermal brayton cycle using high-temperature sealant |
| title_short | Clamped plate-style recuperator for a small-scale solar thermal brayton cycle using high-temperature sealant |
| title_sort | clamped plate style recuperator for a small scale solar thermal brayton cycle using high temperature sealant |
| topic | UCTD Small-scale solar Thermal brayton Clamped plate-style recuperator High-temperature sealant Engineering, built environment and information technology theses SDG-07 SDG-07: Affordable and clean energy Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-13 SDG-13: Climate action |
| url | http://hdl.handle.net/2263/73467 |