Design of an Intelligent Intercooler Control System (IICS) for mitigating performance loss and emission impact in LPG engines at elevated ambient temperatures

Suroto  Munahar; Retno  Rusdjijati; Muhtar  Hanafi; Ari Waryono; Sidqi Mubarok; Muhammad Azhar Alkhadafi; Moehamad Aman

doi:10.61089/aot2026.rjmjxj94

Authors

Suroto Munahar Automotive Mechanical Engineering, Universitas Muhammadiyah Magelang, Magelang, Jawa Tengah, Indonesia Author https://orcid.org/0000-0002-8236-0741
Retno Rusdjijati Industrial Engineering, Universitas Muhammadiyah Magelang, Magelang, Jawa Tengah, Indonesia Author https://orcid.org/0000-0002-3771-5857
Muhtar Hanafi Informatics Engineering, Universitas Muhammadiyah Magelang, Magelang, Jawa Tengah, Indonesia Author https://orcid.org/0000-0003-0670-3359
Ari Waryono Automotive Mechanical Engineering Laboratory, Universitas Muhammadiyah Magelang, Mertoyudan, Magelang, Jawa Tengah, Indonesia Author https://orcid.org/0009-0007-9218-6752
Sidqi Mubarok Automotive Mechanical Engineering Laboratory, Universitas Muhammadiyah Magelang, Mertoyudan, Magelang, Jawa Tengah, Indonesia Author https://orcid.org/0009-0001-6502-0833
Muhammad Azhar Alkhadafi Automotive Mechanical Engineering Laboratory, Universitas Muhammadiyah Magelang, Mertoyudan, Magelang, Jawa Tengah, Indonesia Author https://orcid.org/0009-0004-4120-2028
Moehamad Aman Industrial Engineering, Universitas Muhammadiyah Magelang, Magelang, Jawa Tengah, Indonesia Author https://orcid.org/0009-0002-7033-5167

DOI:

https://doi.org/10.61089/aot2026.rjmjxj94

Keywords:

Intelligent Intercooler Control System (IICS), LPG, self-refrigeration effect, emissions, engine power

Abstract

The increasing demand for environmentally friendly vehicles with optimal engine performance has encouraged the development of cleaner and more efficient alternative fuels, such as Liquefied Petroleum Gas (LPG). LPG has a high octane rating and is suitable for engines operating at high compression ratios. Its use also produces a self-refrigeration effect during depressurization, as the phase transition from liquid to gas absorbs heat. This cooling potential is generally dissipated into the environment, although it can be utilized to reduce intake-air temperature, which is particularly important for maintaining volumetric efficiency and engine power under high ambient temperatures. Therefore, this study developed an Adaptive Intercooler Control System (AICS) that utilizes the LPG self-refrigeration effect as a cooling medium for engine intake air. The AICS was experimentally evaluated on a 135cc engine based on engine performance, heat transfer characteristics, and exhaust emissions. The results showed that AICS operation increased engine power by approximately 0.7–1.0 HP (13–18%) at 4800–5200 rpm and increased torque by 0.2–0.4 Nm at 4000–5000 rpm. At idle speed, the system reduced HC emissions from 1020 to 890 ppm and CO emissions from 5.3% to 4.8%. Thermally, AICS optimized heat transfer within the intercooler, achieving an air-side heat transfer rate of approximately 5.5–5.6 W over 25–35 s. The LPG-side heat transfer rate remained stable at approximately 20–26 W throughout the testing period. These findings demonstrate that controlled utilization of LPG self-refrigeration through AICS can improve intake-air thermal management, enhance engine performance, and reduce exhaust emissions.

Author Biographies

Retno Rusdjijati, Industrial Engineering, Universitas Muhammadiyah Magelang, Magelang, Jawa Tengah, Indonesia

Industrial Engineering, Universitas Muhammadiyah Magelang, Jl. Bambang Sugeng km.05, Mertoyudan, Magelang, 56172, Jawa Tengah, Indonesia
Muhtar Hanafi, Informatics Engineering, Universitas Muhammadiyah Magelang, Magelang, Jawa Tengah, Indonesia

Informatics Engineering, Universitas Muhammadiyah Magelang, Jl. Bambang Sugeng km.05, Mertoyudan, Magelang, 56172, Jawa Tengah, Indonesia

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