Keywords: gas engine, liquefied natural gas, locomotive gas engine, techno-economic and environmental performance.

JSC Kolomzavod in cooperation with ТМХ Holding Engineering Center developed and tested locomotive LNG engine type 9GMG to power shunting locomotive. Its construction is based on serial diesel engine type D49 (8CHN26/26), the both engines having over 80 % parts and components in common. This gas engine features internal carburation. The project included a dedicated test bed equipped with all needed controls and instrumentation. According to the test results, fuel gas consumption (in terms of heat input) is practically equal to that of the basis diesel engine, which results in reduction of fuel costs against similar diesel engines by 30–40 %. Also, noxious emissions are drastically reduced, and СО2 emissions are lowered by 50 % compared with similar diesel engines.

Keywords: two-stroke opposed-piston engine, uniflow scavenging, modeling of combustion process, pumping loss evaluation.

Two-stroke opposed-piston engine is shown as one of the most effective motors based on reciprocating engine thermodynamic cycle. The authors presented the comparative analysis of indicated processes in four-stroke and two-stroke opposed-piston engines. Indicated cycle parameters have been calculated with zero-dimensional cylinder model for a close-loop part of the cycle. Pumping losses have been calculated through computational modeling of gas exchange systems with G-POWER program package. Calculation results demonstrate two-stroke opposed-piston engine as the most advantageous solution in terms of indicated fuel consumption and combustion «softness». In the authors' opinion, opposed-piston engines are much promising for use in vehicles and stand-alone power units.

Keywords: W-engine, valve gear, slave connecting rods.

These authors examine factors that may influence design of electro-hydraulic valve control system for W-engine featuring slave connecting rods, with special emphasis on loads exerted to engine parts and components. Specifications for electro-hydraulic valve control system are formulated. The results of this work may be of particular interest for applications where power unit compactness or engine specific weight are top priorities.

Keywords: hot gas reciprocating engine, control algorithm and mechanism.

The existing systems of hot gas reciprocating engines have been examined for better air-fuel ratio. A device is offered (concept and construction) that controls engine air-fuel ratio as a function of free oxygen content in exhaust gas. Feasibility of such control during the early combustion phase is substantiated, and the description of Russian and worldwide analogs is provided.

Keywords: heat exchange loop, recuperator, number of heat transportation units, R. Meyer rhombic driving gear, heat exchanger dead volume.

History of Stirling engines is closely tied with the development of power industry, focusing on transformation of thermal energy into mechanical work. Modern power industry problems are closely interrelated and cannot be solved separately. From this viewpoint attractiveness of Stirling engines is doubtless, including the growing interest in so-called «green energy». Level of modern technologies immeasurably surpasses that in Robert Stirling epoch, so, numerous chances are there for large-scale implementation of his idea in engineering practice. The core challenge here is development of optimal heat exchange loop that would provide needed effective power of engine, without compromising its fuel efficiency and environmental performance.

Keywords: gas engines, liquefied natural gas (LNG), pilot fuel injection system, heat recuperation system, engine control system ME ECS, gas valve train, operation experience.

Mitsui Engineering & Co., Ltd. (MES) has developed a large size lean-burn gas engine MD36G jointly with DAIHATSU DIESEL MFG. CO., Ltd. (DAIHATSU), rated at 3 to 7 MW. The base engine of MD36G is the medium-speed diesel engine DAIHATSU DK-36, featuring the method of direct-injection micro pilot. To achieve higher generating efficiency MD36G is added with a heat recovery system. As a heat recovery technology, THS (Turbo Hydraulic System) and VPC (Variable Phase Cycle) system have been added to the gas engine system. THS can take the power from excess energy of Turbo Charger and transmits it to the crankshaft. THS is reversible system, which is used to assist Turbo Charger rotation, so that the gas engine could respond more quickly against load fluctuation than before. As a result, generating efficiency of the MD36G itself reaches 48,8 % in V-type and 47,8 % in L-type.

The ME-GI engine from MAN Diesel & Turbo (MDT) is a low-speed, two-stroke, dual-fuel engine that when acting as main propulsion in LNG carriers, can consume natural gas, boil off gas or fuel-oil at any ratio, depending on the energy source available on board. In close cooperation with HHI-EMD and other MDT's partners, multiple test campaigns on various research platforms have been conducted, and from challenges and lessons learned proved that the ME-GI concept is safe, matured and cost efficient. In the CIMAC paper reviewed, the verification of the optimised ME-GI engine design, functionality, performance and reliability, including gas supply systems. Equally, essential knowledge obtained from extensive testing in close cooperation between MDT and partners, has improved the ready-to-apply solutions for gas supply systems and auxiliary equipment, e. g. reliability and efficiency for cryogenic pumps, compressors and Gas Valve Train (GVT). The experience of development and use of the unique ME Engine Control System (ME ECS) allows us to hope that in future all the LNG carriers will feature this safety system.
The CIMAC papers are translated into Russian by G.Melnik, PhD.