An accurate lumped convective plus radiative heat exchanger model for performance-based modelling
There are several thermo-fluid process modelling tools available on the market which can be used to analyze the off-design performance of thermal plants. These tools all offer the user with a simple convective heat exchanger component that requires the design-base process conditions as inputs. The t...
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| Format: | Article |
| Language: | English |
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EDP Sciences
2021-01-01
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| Series: | MATEC Web of Conferences |
| Online Access: | https://www.matec-conferences.org/articles/matecconf/pdf/2021/16/matecconf_sacam21_00007.pdf |
| _version_ | 1818403339712331776 |
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| author | Fuls Wim |
| author_facet | Fuls Wim |
| author_sort | Fuls Wim |
| collection | DOAJ |
| description | There are several thermo-fluid process modelling tools available on the market which can be used to analyze the off-design performance of thermal plants. These tools all offer the user with a simple convective heat exchanger component that requires the design-base process conditions as inputs. The tools would then calculate an effective overall heat transfer factor (UA) and make use of gas flow mass ratios to scale the UA value for off-design conditions. The models employed in these tools assume that the contribution of gas radiation is insignificant, hence only applies convection scaling laws. This paper presents an improved model which considers the contribution of the gas and particle radiation, as is often encountered in the first few heaters in coal fired boilers and heat recovery steam generators. A more fundamental scaling law is applied for the convection scaling and incorporates a cleanliness factor which allows for the consideration of fouling of the heater surfaces. The model’s performance was validated against a discretized tube-level heater model that solves the fundamental convection and radiation terms. The model is accurate within 1% for the cases considered, as compared to more than 20% error if radiation contribution is not considered. |
| first_indexed | 2024-12-14T08:22:41Z |
| format | Article |
| id | doaj.art-89457e418ad3426aad0455ea60433046 |
| institution | Directory Open Access Journal |
| issn | 2261-236X |
| language | English |
| last_indexed | 2024-12-14T08:22:41Z |
| publishDate | 2021-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | MATEC Web of Conferences |
| spelling | doaj.art-89457e418ad3426aad0455ea604330462022-12-21T23:09:45ZengEDP SciencesMATEC Web of Conferences2261-236X2021-01-013470000710.1051/matecconf/202134700007matecconf_sacam21_00007An accurate lumped convective plus radiative heat exchanger model for performance-based modellingFuls Wim0ATProM Research Unit, University of Cape TownThere are several thermo-fluid process modelling tools available on the market which can be used to analyze the off-design performance of thermal plants. These tools all offer the user with a simple convective heat exchanger component that requires the design-base process conditions as inputs. The tools would then calculate an effective overall heat transfer factor (UA) and make use of gas flow mass ratios to scale the UA value for off-design conditions. The models employed in these tools assume that the contribution of gas radiation is insignificant, hence only applies convection scaling laws. This paper presents an improved model which considers the contribution of the gas and particle radiation, as is often encountered in the first few heaters in coal fired boilers and heat recovery steam generators. A more fundamental scaling law is applied for the convection scaling and incorporates a cleanliness factor which allows for the consideration of fouling of the heater surfaces. The model’s performance was validated against a discretized tube-level heater model that solves the fundamental convection and radiation terms. The model is accurate within 1% for the cases considered, as compared to more than 20% error if radiation contribution is not considered.https://www.matec-conferences.org/articles/matecconf/pdf/2021/16/matecconf_sacam21_00007.pdf |
| spellingShingle | Fuls Wim An accurate lumped convective plus radiative heat exchanger model for performance-based modelling MATEC Web of Conferences |
| title | An accurate lumped convective plus radiative heat exchanger model for performance-based modelling |
| title_full | An accurate lumped convective plus radiative heat exchanger model for performance-based modelling |
| title_fullStr | An accurate lumped convective plus radiative heat exchanger model for performance-based modelling |
| title_full_unstemmed | An accurate lumped convective plus radiative heat exchanger model for performance-based modelling |
| title_short | An accurate lumped convective plus radiative heat exchanger model for performance-based modelling |
| title_sort | accurate lumped convective plus radiative heat exchanger model for performance based modelling |
| url | https://www.matec-conferences.org/articles/matecconf/pdf/2021/16/matecconf_sacam21_00007.pdf |
| work_keys_str_mv | AT fulswim anaccuratelumpedconvectiveplusradiativeheatexchangermodelforperformancebasedmodelling AT fulswim accuratelumpedconvectiveplusradiativeheatexchangermodelforperformancebasedmodelling |