A heat‐transfer model for tube fouling in the radiant section of once‐through steam generators
Bibliographic record
Abstract
Abstract Once‐through steam generators (OTSGs) produce steam by recycling produced water in the steam‐assisted‐gravity‐drainage (SAGD) process for extracting Alberta's oil sands via in situ recovery of bitumen. The industry's specifications for water quality, steam quality, and water recycle ratio, as well as high temperature and pressure operations, lead to the fouling of OTSG tubes, which has important economic, safety, and environmental consequences. The roles and mechanisms of inorganic and organic impurities on tube fouling also complicate the study of heat transfer in OTSGs. Heat transfer in OTSGs involves radiation, convection, conduction, forced convection, and boiling. In this investigation on OTSG fouling, a steady‐state mathematical model was built in Microsoft Excel, incorporating industry design data, to demonstrate the impact of tube fouling on heat transfer and tube‐wall temperature. The model predictions indicate that tube fouling introduces a significant thermal resistance that not only decreases the rate of heat transfer but also causes an increase in the tube‐wall temperature such that it could exceed the safe operating limits of the tube material, leading to potential tube failures . Predictions are provided for the average tube‐wall temperature exceeding the recommended operating limit of 700 K over a range of foulant thermal conductivity (ie, 0.05‐2 W m −1 K −1 ) and foulant thickness (ie, 0.4‐11 mm corresponding to 0.1%‐30% of the tube radius).
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".