Efficiency Analysis of Minichannel Heat Exchangers for High-Concentration Photovoltaic Systems
Year: 2026
Type: article
Abstract: High-Concentration Photovoltaic (HCPV) systems operate under high heat fluxes, on the order of MW/m2, requiring effective thermal management. Experimental studies of minichannel cooling for HCPV seldom extend from the laboratory to complete modules operating outdoors. This study experimentally evaluates seven water-cooled minichannel heat exchangers at three scales: a laboratory setup with electrical cartridge heating, outdoor single-cell monomodules, and complete 25-cell modules. Six were micromachined in aluminum, and one was manufactured in a cobalt–chromium–tungsten (CoCrW) alloy by Direct Metal Laser Sintering (DMLS). The total thermal resistance ranged from 0.24 to 0.84 °C/W, while pressure drops remained below 2 kPa at 60 mL/min. An empirical Nusselt number correlation for the tested straight-channel heat exchangers (22 ≤ Re ≤ 107) predicted 96% of the experimental data within ±30%. Under outdoor operation, the two modules, one equipped with the aluminum heat exchangers and the other with the CoCrW heat exchangers, achieved electrical efficiencies of 23.02% and 22.01% and combined efficiencies of 43.62% and 42.33%, respectively, with cell temperatures between 40 and 50 °C. The exergy content of the recovered thermal energy was 2–3%, so the module exergy efficiency of approximately 25% was determined mainly by the electrical output. Overall, the results demonstrate the potential of minichannel heat exchangers for simultaneous thermal and electrical energy recovery in HCPV modules.
Source: Processes
DOI: 10.3390/pr14213582
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,896
OpenAlex ID: W7225330855