PREDICTION OF DISCHARGE CAPACITY ACCORDING TO EOS MODELS FOR POSRV IN HYDROGEN REFUELING STATIONS

E.J. Jo; S.H. Han; G.B. Min

doi:10.6112/kscfe.2026.31.3.100

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Original Article

PREDICTION OF DISCHARGE CAPACITY ACCORDING TO EOS MODELS FOR POSRV IN HYDROGEN REFUELING STATIONS 수소충전소용 파일럿형 안전릴리프 밸브의 상태방정식 모델에 따른 분출용량 추정 관련 연구

30 September 2026. pp. 100-113

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Abstract

In high-pressure gaseous hydrogen refueling stations, the discharge capacity of a pilot- operated safety relief valve(POSRV) is a key design parameter for overpressure protection. At an inlet pressure of 87.5 MPa, however, hydrogen exhibits pronounced real gas behavior, and the API 520 methodology, which assumes ideal gas isentropic nozzle flow, may not accurately predict the discharge capacity. As no domestic facility is available for certified discharge capacity testing, a model-based approach is required. In this study, the POSRV discharge capacity was evaluated using six approaches: the API 520 analytical equation, a modified API formulation incorporating the real gas compressibility factor and isentropic exponent, and CFD simulations employing the ideal gas, NIST REFPROP, Peng-Robinson(PR), and Aungier-Redlich-Kwong(Aungier-RK) equations of state. Analyses were performed at -40°C, 20°C, and 170°C under 87.5 MPa, with the REFPROP result used as the reference. All approximate methods overpredicted the discharge capacity, with the largest deviations for the API 520 and ideal gas models; the discrepancies decreased with increasing temperature, while the Aungier-RK model showed the closest agreement with the reference. These findings demonstrate that the ideal-gas assumption and simplified API formulations can significantly overestimate discharge capacity at lower temperatures, and that accurate prediction requires rigorous representation of real gas properties, particularly density and speed of sound.

Keywords

고압 기체수소 (High-pressure gaseous hydrogen)

파일럿형 안전릴리프 밸브(POSRV)

전산유체역학(CFD)

분출용량(Discharge capacity)

상태방정식(Equation of State, EoS)

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Information

Publisher :Korean Society for Computational Fluids Engineering
Publisher(Ko) :한국전산유체공학회
Journal Title :Journal of Computational Fluids Engineering
Journal Title(Ko) :한국전산유체공학회지
Volume : 31
No :3
Pages :100-113
Received Date : 2026-06-23
Revised Date : 2026-07-08
Accepted Date : 2026-07-24
DOI :https://doi.org/10.6112/kscfe.2026.31.3.100

Journal of Computational Fluids Engineering ISSN:1598-6071(Print) 3022-6252(Online) 한국전산유체공학회지

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