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Advanced Exergy-Based Optimization of a Polygeneration System with CO2 as Working Fluid
Jing Luo1, Qianxin Zhu1, Tatiana Morosuk1
1Institute for Energy Engineering, Technische Universität Berlin, Marchstr. 18, 10587 Berlin, Germany.
Entropy (Basel, Switzerland)
|October 25, 2024
Summary
This study optimized a polygeneration system using waste heat and CO2. The enhanced system achieved significant improvements in energy efficiency and cost reduction.
Area of Science:
- Thermodynamics and Energy Systems Engineering
- Sustainable Energy Technologies
- Waste Heat Recovery
Background:
- Polygeneration systems offer cost-effective energy efficiency improvements for sustainable development.
- Low- to medium-grade waste heat utilization is crucial for reducing environmental impacts.
- Carbon dioxide (CO2) is investigated as a working fluid for simultaneous power, refrigeration, and heating.
Purpose of the Study:
- To investigate and optimize a polygeneration system powered by waste heat using CO2 as the working fluid.
- To evaluate system performance using advanced exergy-based methods and exergoeconomic analysis.
- To identify improvement potential and propose engineering solutions for enhanced system efficiency and cost reduction.
Main Methods:
- System simulation using Aspen HYSYS®.
- Advanced exergy-based methods for exergy destruction and cost analysis.
- Exergoeconomic graphical optimization at the component level.
Main Results:
- The optimized system demonstrated a 15.4% improvement in exergetic efficiency and a 7.1% reduction in average product cost compared to the base case.
- An engineering solution further increased system exergetic efficiency by 11.3% and decreased average product cost by 8.5%.
- Avoidable exergy destruction and investment costs were identified as key areas for improvement.
Conclusions:
- Polygeneration systems utilizing waste heat and CO2 are effective for energy efficiency and cost reduction.
- Advanced exergy and exergoeconomic analyses provide valuable insights for system optimization.
- The proposed engineering solutions offer practical pathways for enhancing the performance of waste heat-powered polygeneration systems.
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