OCEAN-RAD P1: Conceptual Design, Numerical Modelling and Test Protocol for Radiative Cooling of Enclosed Seawater Tanks (v1.1)

OCEAN-RAD P1 is a preliminary engineering study investigating radiative sky cooling as a potential means of removing heat from enclosed seawater tanks. The proposed laboratory configuration comprises 2 m² of radiating panels, a closed freshwater circulation loop and a titanium heat exchanger coupled to a 100-litre seawater tank. Initial testing is intended to take place on land, without organisms, primarily under nocturnal conditions. The study provides a thermal model, reproducible Python code, synthetic parameter studies, a proposed experimental protocol, measurement templates and an internal technical review. A second numerical implementation reproduces the steady-state results across 1,008 prescribed parameter combinations. This agreement demonstrates computational consistency under shared assumptions; it does not establish experimental validity. Under one prescribed favourable nocturnal scenario, the model predicts an initial heat extraction rate of approximately 78 W. Performance depends on atmospheric radiation, temperatures, heat-transfer coefficients and component properties. The reported values are conditional numerical results rather than measured or representative coastal performance. Version 1.1 distinguishes heat transported between the heat-exchanger ports from heat extracted from the seawater, accounting for changes in the exchanger’s stored thermal energy during transients. It also strengthens data validation, extends uncertainty accounting and revises the proposed startup procedure. No prototype testing or biological experiments have been conducted. Practical efficiency, durability, economic viability and ecological benefits remain unverified. The work is intended to support laboratory evaluation and possible future applications in small, controlled marine facilities; it does not demonstrate cooling of the open ocean or a net planetary cooling effect. AI tools were used for technical drafting, numerical implementation and internal review. The internal review used the same AI system and does not constitute independent external peer review.