Keywords: medium-speed diesel engine, gas joint components, mechanical and thermal stresses, finite element method, tie rods, pull-force, pressure distribution in a gasket.

A method is offered for analysis of a gas joint a high-powered medium-speed diesel engine for leak-tightness, when a known pull-force is exerted to the tie rods. The method in question is based on FEM analysis of mechanical and thermal stresses in gas joint components. Stress magnitudes in gas joint components are evaluated. as well as local pressure distribution in a gasket vs. tie rod pull-force.

Keywords: gas engine, spark ignition, lean combustible mixture,combustion chamber geometry, outlet duct geometry, fuel charge swirl, numerical simulation of combustion process.

The authors investigated dependence of such parameters as charge turbulization & eddy formation, velocity of fuel/air mixture combustion, indicating and environmental performance of a gas engine on combustion chamber geometry and inlet duct orientation. Numerical simulation of combustion process was carried out. Then one of two inlet valves was replaced with tangential-type one, in order to induce swirls, increase flow turbulence and combustion velocity, which, in turn, results in higher fuel efficiency. Combustion process was simulated with Ansys Forte code.

Keywords: high-speed diesel engine, biofuel, methanol, ethanol, spirit-fuel emulsion, rapeseed oil ether, improvement of emission performance.

Biofuel is shown as a means to substantially improve emission performance of a small high-speed diesel engine. The authors offered optimum compositions of spirit-fuel emulsions of ethyl and methyl alcohol, as well as those consisting of methanol and rapeseed oil methyl ether. As far as diesel engines D/S = 11/12,5 and D/S = 10,5/12 are concerned, change from conventional to alternative fuels results in emission reducing as follows: NOx — by 30–47 %, СО — by 30–48 %, smoke (FSN) — several times as low. Due to lower carbon contents, using biofuel results in decrease in СО2 emissions by more than 10% (as compared with conventional fuel).

Keywords: reciprocating engine, unified information space, power units and their components, CALS technologies, predictive modelling.

A method is described of how to form unified information space for designing power units built around reciprocating engines. Optimization of W-engine connecting rod is taken as an example of CALC usage for diesel engine development, taking account of its application and manufacturing methods. CALC implementation allows to considerably reduce costs of new products, rapidly respond to market demand and customers' needs, and develop competitive power units.

Keywords: marine diesel engines, candidates for renovation, resource saving, renewal, secondary life cycle, utilization.

Basic principles and problems are set forth of renovation of marine diesel engines and their components whose usefulness is not yet outlived, as a form of their utilization so as material and energy resources involved in their production would be partially recovered. Main stages of renovation are considered as sequence of jobs targeted at recovery of consumer properties of items under renovation to an extent allowing their further operation in new life cycles. More extensive renovation is shown as a driver of energy & material saving and mitigation of environmental impact.

Keywords: automobile engine, diagnostics, cranking, sleeve assembly, leak-tightness, crankcase gas pressure, non-conformance criteria.

Rapid methods of sleeve assembly testing for leak-tightness are compared. The article is focused on the cranking method. The method is based on measurement of crankcase gas pressure during cranking, which pressure depends on gas leak rate through the clearance between sleeve and piston / piston ring. The method was tested on engines with different life cycles. Based on the test results, non-conformance criteria have been derived.

Keywords: Diesel-generator, exhaust gas, heat recovery, active waste heat boiler, combustion of solid fuel, high-temperature fluidized bed.

The experiment was carried out on stand-alone combined-cycle power plant featuring diesel-generator and active waste heat boiler operating on solid fuel. Waste heat was recovered by feeding exhaust gas to high-temperature fluidized bed of a waste heat boiler. The test allowed to derive values of increase in boiler efficiency, solid fuel saving, and upper limit of excess oxygen ratio as a function of exhaust gas flowrate to the waste heat boiler. The test results largely agreed with respective calculated values.

Keywords: marine engines, controlled emission zones, IMO Tier III, black carbon, particulates, measurement methods, regulatory outlook.

Appropriateness of expectable new controlled emission zones (ЕСА), where upper limit of NOx emissions from ships should be decreased by 80%, remains to be one of the most arguable issues discussed by engine specialists. Global coming into force of IMO Tier III requirements was not a success, because shipbuilders, ship owners and port authorities found themselves unready as yet to operate and serve ships powered by engines meeting the above requirements. Problems faced by ship owners when IMO Tier III entries into force for Baltic and Northern seas since 01.01.2021 are presented in paper prepared by Schiffahrtsgesellschaft GmbH & Co KG (Germany). A regulatory outlook for emissions of black carbon (BC), which is one of particulate matter (PM) compositions, is prepared by DNV & GL Classification Society. Subject matter of discussions in IMO Committee concerning this problem includes methods of measuring РМ/BC emissions from ships and most urgent measures for their abatement.