As carbon-neutral energy transition accelerates, hydrogen-enriched natural gas has emerged as a promising transitional fuel for industrial combustion systems, gas engines, and distributed energy applications. However, due to the significant differences in physical properties between hydrogen and natural gas, the conventional fuel supply system designed for methane-dominant operation may experience instability in pressure regulation, flow control, mixing uniformity, and safety performance under blended fuel conditions. This study analyzes the system configuration and operational characteristics of a natural gas/hydrogen blended fuel supply device with a focus on pressure regulation, mixing control, and safety design. The major subsystem functions, including gas reception, pressure reduction, flow metering, proportional mixing, leak prevention, and emergency shutdown, are reviewed based on engineering design requirements. Furthermore, the influence of hydrogen blending ratio on flow behavior, pressure fluctuation, and combustion supply stability is theoretically examined. The results indicate that hydrogen blending increases the sensitivity of pressure drop and flow control due to lower density, higher diffusivity, and wider flammability characteristics. Accordingly, a dedicated integrated fuel supply architecture consisting of multi-stage pressure regulation, real-time mixing control, leak monitoring, and interlock-based safety shutdown is required for stable operation. This study provides a practical engineering basis for the design and application of blended fuel supply devices in hydrogen transition energy systems.

Abstract
1. 서 론
2. 천연가스/수소 혼합연료 공급장치의기술적 배경
    2.1 혼합연료 공급장치의 기능 요구사항
    2.2 관련 기준 및 기술 동향
3. 천연가스/수소 혼합연료 공급장치의시스템 구성
    3.1 시스템 구성 개념
    3.2 가스 수용부 및 차단부
    3.3 압력 조정부
    3.4 유량계측 및 혼합제어부
    3.5 안전 및 차단부
    3.6 감시 및 제어부
4. 혼합연료 공급장치의 운전 특성분석
    4.1 압력손실 및 유량 특성
    4.2 혼합비 제어 안전성
    4.3 공급 안정성 및 압력 응답성
    4.4 안전성 평가
5. 시스템 설계 방향 및 고찰
6. 결 론
후 기
References

• 정진홍(President, Gaonens Co., Ltd. Doctor of Engineering in mechanical systems) | Jin-hong Jung Corresponding author