Proceedings of the
5th International Seminar on
ORC Power Systems
9 - 11 September 2019, Athens Greece
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Experimental Study on the Influence of Heat Exchanger on the Organic Rankine Cycle Performance


Go-down orc2019 Tracking Number 64

Presentation:
Session: Session 7C: Heat Exchangers (2)
Room: Templar's
Session start: 11:10 Wed 11 Sep 2019

Yingzong Liang   yliangam@connect.ust.hk
Affifliation:

Xianglong Luo   lxl-dte@gdut.edu.cn
Affifliation:

Xiaosheng Zheng   1107968626@qq.com
Affifliation:

Jianyong Chen   jianyong@gdut.edu.cn
Affifliation:

Zhi Yang   yangzhi0610@163.com
Affifliation:

Ying Chen   chenying@gdut.edu.cn
Affifliation:


Topics: - Experimental activities and techniques (Topics)

Abstract:

Organic Rankine cycle (ORC) is a common accepted low-grade heat-to-power technology. Although the ORC has been extensively investigated in the past decades, experimentally validated works occupy only a small fraction of published literature. The experimental test rig in most of the previous studies are mostly focus on the expander, cycle configuration, working fluid, and system performance. The experimental investigation on the heat exchanger is quite limited though the heat exchanger occupies important role in investments cost and irreversible loss. In the present study, a novel ORC experimental test rig with switchable heat exchangers and scroll expander is introduced. The steady test is first conducted. Then, the influence of working fluid flowrate from 0.1kg/s to 0.16kg/s on the cycle performance is conducted for ORC1 with 6.56m2 evaporator and 13.59m2 under design conditions. Next, the component and cycle performances are investigated under different heat source temperature range from 120oC to 140oC and heat sink temperature range from 15 oC to 25 oC. Finally, the system performance test and comparison are conducted for six ORCs with different heat exchanger area, namely ORC1, ORC2 with 6.56m2 evaporator and 10 m2, ORC3 with 6.56m2 evaporator and 5.42m2, ORC4 with 3.71m2 evaporator and 13.59m2, ORC5 with 3.71m2 evaporator and 10 m2, ORC6 with 5.42m2 evaporator and 13.59 m2. Results show that the thermal efficiency of ORC first increases then decreases with working fluid mass flowrate for ORC1 under design heat source/sink conditions. The thermal efficiency of ORC increases with the inlet temperature difference of heat source and heat sink. ORC2 features the maximum thermal efficiency at working fluid flow rate 0.12kg/s, heat source temperature 150oC, and heat sink temperature 15oC. The comparison between different ORCs show that the condenser area is large than assumed and the pinch point temperature difference is very small in most of the studied operating conditions. The results show that the ORC performance is remarkably affected by the heat exchanger size and the present experimental study provide a valuable guidance for the reasonable heat exchanger design and to improve the ORC performance.