Incident radiation flux → Useful heat

Matrix context

D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.

D.11 × C.20 · Incident radiation flux × Photothermalfamily: Photothermal

Typed bounds on this route

Every limit the atlas holds for this route, as constraint records: reached through bounded_by claims on the route's own entities. Hard bounds (an upper bound or a formula) decide the thermodynamic-bound check above; benchmarks, constitutive relations and resource limits are listed and never decisive. No prose limit exists anywhere (pass 42).

• Landsberg limit · formula-bound · hard, applies to this route
  η ≤ 1 − (4/3)(T_c/T_s) + (1/3)(T_c/T_s)⁴ for conversion of blackbody radiation at T_s with a sink at T_c; 93.3 % at 6000 K / 300 K
• Carnot limit · formula-bound · hard, filtered out by its applicability
  η ≤ 1 − T_c/T_h for any heat engine between reservoirs at T_h and T_c

Steps

1. 01
   Incident radiation flux —drives→ Photothermal absorptionestablishedclaim record

   radiative → thermal

   • an absorber with high solar absorptance; selective surfaces suppress re-emission

   illumination required

   refs [1] [2]
2. 02
   Photothermal absorption —produces→ Temperature gradientestablishedclaim record

   thermal → thermal

   refs [1]
3. 03
   Temperature gradient —drives→ Advective heat transportestablishedclaim record

   thermal → thermal

   • a bulk fluid flow connects the hotter and colder regions
   • for forced circulation the flow may be supplied by an external pump rather than generated by buoyancy

   refs [1] [3] [4]
4. 04
   Advective heat transport —produces→ Heat flowestablishedclaim record

   thermal → thermal

   refs [1] [3]
5. 05
   Heat flow —converts into→ Useful heatestablishedclaim record

   thermal → thermal

   • heat delivered at a temperature above the point of use

   refs [1]

Evidence for the complete composition · 0

No source on record for this exact composition. The sources below support the individual steps, not the route as a whole.

Evidence for the constituent relations · 4

1. [1]
   A. Bejan. Advanced Engineering Thermodynamics (4th ed.) (2016)

   Wiley · doi:10.1002/9781119245964 · crossref ✓ 2026-09-19 · record
2. [2]
   P. T. Landsberg, G. Tonge. Thermodynamic energy conversion efficiencies (1980)

   Journal of Applied Physics 51, R1–R20 · doi:10.1063/1.328187 · crossref ✓ 2026-09-19 · record
3. [3]
   U.S. Nuclear Regulatory Commission. Pressurized Water Reactors — how a typical commercial PWR works (2025)

   nrc.gov · www.nrc.gov/reactors/power/pwrs · record
4. [4]
   U.S. Department of Energy. DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2 of 3 (DOE-HDBK-1012/2-92) (1992)

   DOE-HDBK-1012/2-92, June 1992 · www.energy.gov/sites/default/files/2026-04/DOE-HDBK-1012-92_VOL2.pdf · record