Blade Cup Method for Cavitation Reduction in Marine Propellers

Energy efficiency has become more important in every industry and daily life. Designing and building a more efficient marine vehicle can lead to lower fuel consumption and a longer lifetime for the components of the vehicle. Erosion caused by cavitation reduces the service life of the propeller and the related components in the propulsion and maneuvering system. Reducing cavitation leads to a longer life for these components. This paper aims to explain and investigate propeller blade cup as a cavitation reduction method for marine propellers. A cavitating no-cup propeller is created and analyzed then the cupped version of this propeller is generated and analyzed to compare with the no-cup propeller. Cavitation results of these propellers are investigated. In addition, the thrust, torque, and efficiency of the propellers are compared.

Internal exhaust gas recirculation via reinduction and negative valve overlap for fuel-efficient aftertreatment thermal management at curb idle in a diesel engine

Low air-flow diesel engine strategies are advantageous during low load operation to maintain temperatures of a warmed-up aftertreatment system (ATS) while reducing fuel consumption and engine-out emissions. This paper presents results at curb idle for internal EGR (iEGR) that demonstrate low airflow and reduced engine-out emissions during fuel-efficient ATS temperature maintenance operation. Internal EGR via reinduction and trapping using negative valve overlap (NVO) are compared to each other, conventional operation and to other low airflow approaches including cylinder deactivation (CDA). At 800 RPM/1.3 bar BMEP (curb idle) iEGR via reinduction enables 200°C engine-out temperature combined with 70% lower NO X, 35% lower fuel consumption, and 40% lower exhaust flow rate than conventional thermal management operation. Internal EGR via trapping using NVO resulted in an engine-out temperature of 185°C, with 56% lower NO X and 25% lower fuel consumption than conventional thermal management operation. Both iEGR strategies have lower engine-out temperatures and higher exhaust flow rates than CDA. No external EGR is required for either iEGR strategy. “iEGR via reinduction” outperforms “iEGR via NVO” as a result of higher open cycle efficiency (via less pumping work) and higher closed-cycle efficiency (via higher specific heat ratio).

DESIGN A VERTICALLY FLARING FURNACE OF A DELAYED COKING UNIT JSC «ANHK»

In the work, the project is the replacement of a hip furnace of a delayed coking unit for vertically-torch furnace with higher technical and economic performance and lower fuel consumption.

THE DESIGN OF A VERTICAL-TORCH FURNACES FOR CARBONIZATION UNIT

In the work, the project is the replacement of a hip furnace of a delayed coking unit for vertically-torch furnace with higher technical and economic performance and lower fuel consumption.

Burner Design for biogas-fuelled Stirling engine for electric power generation

The Stirling engine is an external combustion where the fuel combustion process takes place outside the cylinder, at the combustion chamber or burner. Stirling engine offers flexibility of fuel used for the power generation hence is a potential substitute to fossil fuelled internal combustion engine and contribute toward more sustainable power generation. In this study a burner for Gamma V2-6 Stirling engine is designed and developed for a biogas-fuelled power generation system. The heat used to power the Stirling engine is obtained from combustion of biogas at the burner. The system has 5 kW capacity fuelled by 165 kg/day solid waste (biowaste) from local farm. The bio-digester needed is 20 m3. The combustion temperature of the burner is in the range of 600 to 1000°C. The required fuel input is 60,000BTU/hr or equivalent to 17 kW. The system requires constant heat from the combustion chamber hence a specific burner is designed to fulfil the purpose and accommodate biogas composition and optimum heat transfer to the engine. The burner is able to provide for simultaneous air preheater for lower fuel consumption leading to 37% lower fuel consumption.

Performance Improvements in Cooker-Top Gas Burners for Small Aspect Ratio Changes

This paper aims to identify performance improvements in cooker-top gas burners for changes in its original geometry, with aspect ratios (ARs) ranging from 0.25 to 0.56 and from 0.28 to 0.64. It operates on liquefied petroleum gas (LPG) and five thermal power (TP) levels. Considering the large number of cooker-top burners currently being used, even slight improvements in thermal performance resulting from a better design and recommended operating condition will lead to a significant reduction of energy consumption and costs. Appropriate instrumentation was used to carry out the measurements and methodology applied was based on regulations from INMETRO (CONPET program for energy conversion efficiency in cook top and kilns), ABNT (Brazilian Technical Standards Normative) and ANP—National Agency of Petroleum, Natural Gas (NG) and Biofuels. The results allow subsidizing recommendations to minimum energy performance standards (MEPS) for residential use, providing also higher energy conversion efficiency and/or lower fuel consumption. Main conclusions are: (i) Smaller aspect ratios result in the same heating capacity and higher efficiency; (ii) higher aspect ratios (original burners) are fuel consuming and inefficient; (iii) operating conditions set on intermediate are lower fuel consumption without significant differences in temperature increases; (iv) Reynolds number lower than 500 provides higher efficiencies.

Reduction of Drillship’s Moonpool Drag during Transit

Due to unrestricted ocean operations of a drillship, the importance of its transit speed is increasing in the viewpoint of reducing the downtime of offshore operations to a minimum. The open moonpool in a drillship induces additional drag when the ship is in transit. As an unfavorable moonpool design may cause the excessive drag, various ways to reduce the drag have been studied in theoretical and experimental methods. In this paper, an efficient way to reduce the drag due to moonpool and consequently increase the transit speed has been proposed. The reduction of moonpool drag has been focused as the moonpool drag is around 30% of total resistance of the drillship. A simple and efficient shape to mitigate excessive water motion inside the moonpool during drillship's transit is developed and verified through a series of model tests at SSMB (Samsung Ship Model Basin). Based on the observation during the model tests, it is found that a remarkable drag reduction can be achieved by the devised moonpool shape. Thus, it is concluded that more economical operation of a drillship such as the lower fuel consumption and increase of working time can be expected.

An overview of particle number emission from direct injection SI engine in scope of new legislation rules

The main advantages of using direct injection in an SI engine, such as lower fuel consumption and higher thermal efficiency, implicate a new problem concerning gasoline engines: the emission of particulate matter. The observed issue has been a significant direction of development of the contemporary DISI engine over the last decade. This paper contains an overview of the results of PN emission, which were obtained from experiments conducted at BOSMAL and from the literature. Current and future legal regulations regarding PN emissions were collated to the test results.