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UID:pretalx-amfc2026-Y7ZQLD@modelica.simtek.cc
DTSTART;TZID=CST:20260922T141500
DTEND;TZID=CST:20260922T144000
DESCRIPTION:Fluctuations in offshore low-temperature heat sources and cold 
 seawater alter the heat input\, heat rejection\, and condensing pressure o
 f organic Rankine cycle (ORC) systems\, making reliable off-design assessm
 ent important for marine power conversion. This study investigates a close
 d R134a ORC subjected to hot- and cold-source temperature and flow variati
 ons. A variable-condensingpressure model is developed in Modelica. The eva
 porator and condenser are discretized using the finite-volume method\, and
  receiver pressure is determined from coupled mass and energy balances\; t
 he working-fluid mass flow is maintained at 0.50 kg/s. Steady-state matric
 es are used to quantify pressure\, phase state\, net power\, and thermal e
 fficiency. At 363.15 K and 2.50 kg/s on the hot side and 288.15 K and 1.53
  kg/s on the cold side\, the model gives high/low pressures of 2.496/0.793
  MPa\, net power of 4.557 kW\, thermal efficiency of 4.66%\, and receiver 
 level of 0.501. Across the normal cold-source-temperature cases\, condensi
 ng pressure and net power vary by 29.7 kPa and 0.185 kW\, respectively\; t
 he corresponding ranges over the cold-source-flow matrix are 35.5 kPa and 
 0.224 kW. The 359.15 and 360.15 K hot-source cases lead to wet expansion\,
  whereas the 278.15 and 283.15 K cold-source cases cross the pump-inlet ph
 ase boundary. Refined calculations over the 89-90 °C hot-source interval 
 show increases of 0.128 kW in net power and 1.532 kW in evaporator heat in
 put\, with thermal efficiency increasing from 4.606% to 4.664%. These resu
 lts quantify the distinct effects of heat-input and heat-rejection variati
 ons under variable condensing pressure and identify the associated phase b
 oundaries.
DTSTAMP:20261004T070610Z
LOCATION:Energy (R2002)
SUMMARY:Modelica-Based Performance Analysis of an Organic Rankine Cycle und
 er Marine Hot- and Cold-Source Variations - Hongfei Zhu\, Xiao Yan\, Ming 
 Ding
URL:https://modelica.simtek.cc/amfc2026/talk/Y7ZQLD/
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