Journal of Hydrogen and New Energy (한국수소및신에너지학회논문집)

The Korean Hydrogen and New Energy Society (한국수소및신에너지학회)
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Comparative Study between Single-stage and Two-stage Expansion Using LNG Cold Heat

액화천연가스 냉열을 이용한 단일팽창과 이단팽창 사이의 비교 연구

  • NOH, SANGGYUN (Department of Chemical & Biomolecular Engineering, Dongyang University)
  • 노상균 (동양대학교 화공생명공학과)
  • Received : 2019.03.20
  • Accepted : 2019.04.30
  • Published : 2019.04.30
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Abstract

Comparative studies between single- and two-stage expansion process using LNG cold heat have been performed for a closed Rankine power generation cycle. PRO/II with PROVISION release 10.0 from Schneider Electric Company was used, and the Peng-Robinson equation of state model with Twu's alpha function was selected for the modeling and optimization of the power generation cycle using LNG cold heat. In two-stage power generation cycle, 6.7% more power was obtained compared to that of single-stage power generation cycle through the optimization works.

Keywords

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Fig. 2. PRO/II flow sheet diagram for a closed single-stage Rankine power generation cycle using LNG cold heat

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Fig. 3. PRO/II flow sheet diagram for a closed two-stage Rankine power generation cycle using LNG cold heat

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Fig. 4. Total power obtained from two expanders vs. expander outlet pressure

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Fig. 1. Flow sheet diagram for a closed Rankine power generation cycle

Table 1. Power generation cycle simulation results summary

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Table 2. LNG compositions

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Table 3. Critical temperature, critical presssure and acentric factor

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Table 4. Coefficients in alpha function

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Table 5. Melting point and critical pressure of propane

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Table 6. Single-stage Rankine cycle results summary

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Table 7. Double-stage Rankine cycle results summary

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References

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