Evaluation of Exhaust characteristics and Fuel Efficiency Based on Demonstration Tests of a Hydrogen Internal Combustion Engine Hydraulic Excavator

Haru Nabata (Kanazawa Institute of Technology)･Tadashi Enomoto･Takuya Yamaura (Flat Field Co., Ltd.)･Yuki Ninomiya (Oriental Consultants Co., LTD.)･Akemi Ito (Tokyo City University)･Kaname Naganuma (Kanazawa Institute of Technology)

For the purpose of technological development of a Hydrogen Internal Combustion Engine Hydraulic Excavator, an actual machine was built and operational data was obtained through demonstration tests. As a result, characteristic NOx emission characteristics caused by the hydraulic excavator's unique operating point transition were revealed. However, the NOx values were low and showed the possibility of being below the regulation values for diesel engine hydraulic excavators of the same class without requiring after-treatment equipment during HOT operation.

Study on Argon Circulated 2- Stroke Hydrogen Engine

ZHE WANG･TAKAHARU ABE･ZHILI CHEN (Tokai University)

Argon circulated hydrogen engines have higher thermal efficiency but tend to knock. 2-stroke engines can reduce knocking because the fuel required per cycle is about half that of a 4-stroke engine. On the other hand, since the exhaust gas is circulated, the fuel loss due to scavenging and the emission of lubricating oil problems in 2-stroke engines no longer exist. In this study, an argon circulated 2-stroke hydrogen engine was proposed, and the engine performance was investigated through tests on a commercial engine.

Study on the Effect of Circulation system Pressure in an Argon Circulated Hydrogen Engine

Uta Kondo･Ryouta Kiyokawa･Zhili Chen (Tokai University)

In argon circulated hydrogen engines, the effect of supercharging can be achieved without the use of a turbocharger if the circulation system is pressurized, however, the effects on combustion and pumping losses have not been studied. In this research, the circulation system was pressurized to 100 kPa to prevent knocking and increase power output. The engine operating ranges, power output, thermal efficiency, combustion, and pumping loss were investigated.

Considerations for Maximizing the Thermal Efficiency of a Highly Boosted Port-Injected Hydrogen Engine

Shojun Rachi･Tsukasa Yamazaki･Yuhei Sakane (Kanazawa Institute of Technology)･Tadashi Enomoto･Takuya Yamaura (Flat Field Co., Ltd.)･Akemi Ito (Tokyo City University)･Ryuiti Sasaki (Riken Corporation)･Masaya Yoshioka (HOROBA, Ltd.)･Kodai Ichikawa (NGK INSULATORS)･Kaname Naganuma (Kanazawa Institute of Technology)

The hydrogen engine has a distinctive feature compared to gasoline and diesel engines, as its control settings for boost pressure, air-fuel ratio, and ignition timing cover a much wider range. In this study, aiming to maximize thermal efficiency, the effects of various control settings and their combinations on thermal efficiency were examined based on bench test results. This study reports the effects of various specifications and settings, including the compression ratio, on heat balance.

Clarification of the Mechanism of Abnormal Combustion in Hydrogen Engines (Part I: Investigation of Abnormal Combustion Location by Numerical Analysis)

Pravin Ananta Kadu･Takao Nakayama･Kei Yoshimura･Keiji Muramatsu･Takuya Kosugi･Kenjiro Nakama (Suzuki Motor)

Hydrogen fueled internal combustion engines are susceptible to autoignition which may damage engine. To investigate its cause, root cause analysis was conducted at lean premixed condition. Ignition delay time for hydrogen at different conditions was obtained from chemical kinetics simulations. 1D CFD was then used to investigate the pressure and temperature conditions of exhaust gas and engine components. Based on these conditions and shorter ignition delay, most probable causes of autoignition were judged. 3D CFD and experimental results were used to confirm this finding.

Clarification of the Mechanism of Abnormal Combustion in Hydrogen Engines (Part II: Investigation of Abnormal Combustion Location by Visualization Measurement)

Keiji Muramatsu･Satoshi Tokuhara･Pravin Ananta Kadu･Kei Yoshimura･Kenjiro Nakama (Suzuki Motor)

In the development of hydrogen engines, torque constraints and the degradation of component reliability due to abnormal combustion are problems. To clarify the mechanism of abnormal combustion, a multi-cylinder visualization engine equipped with visualization windows was constructed, and in-cylinder visualization measurements were conducted. Using the measurement results and the analysis results reported in the first report, an analysis was conducted on the locations and causes of abnormal combustion.