International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

In this paper is performed energy analysis of the dual-flow dissymmetrical low pressure steam turbine, which operates in a coalfired power plant. Based on the measured operating parameters during exploitation it is calculated and presented an ideal and real power, energy losses and energy efficiencies of a whole turbine and both of its cylinders. Right cylinder of the analyzed turbine develops higher real (polytropic) and ideal (isentropic) power in comparison to left turbine cylinder. The first steam extraction of each cylinder dictates cylinder power (both ideal and real). Right cylinder has a higher energy loss and energy efficiency in comparison to left cylinder – the difference in energy loss is notable (5735.74 kW in comparison to 5447.23 kW), while the difference in energy efficiency is low, almost negligible (92.371% in comparison to 92.357%). Percentage differences between observed turbine cylinders show that left cylinder has approximately 5% lower real (polytropic) as well as ideal (isentropic) power and simultaneously approximately 5% lower energy loss.

This paper present analysis of energy flow streams through the main steam turbine (the turbine is used for commercial LNG carrier propulsion) at three different loads. An increase in the propulsion plant (and proportionally increase in the main turbine) load resulted with an increase in energy flow streams and with an increase in the amount of water droplets inside steam at the main turbine outlet. Analyzed turbine has three steam extractions which opening as well as the amount of energy flow stream delivered through each extraction, significantly differs at various loads. The analysis shows that the highest energy flow stream consumers from the main turbine are deaerator and high pressure feed water heating system.

The paper presents numerical analysis of in-cylinder pressure and temperature change for naturally aspirated gasoline engine and two of its upgrades – upgrade with turbocharger only and upgrade with turbocharger along with air cooler. Numerical analysis was performed with 0D (zero-dimensional) numerical model. In-cylinder temperatures, for each engine rotational speed, are the highest for engine upgraded only with the turbocharger. The highest observed in-cylinder temperature of turbocharged engine was obtained at 5000 rpm and amounts 2542.4 °C. In-cylinder pressures are the highest for engine upgraded with turbocharger and air cooler for all rotational speeds except the highest one. The highest observed in-cylinder pressure of a turbocharged engine with air cooler was obtained at 5000 rpm and amounts 129.7 bars. Presented analysis showed that the selected air cooler can be improved at highest engine rotational speed.