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

In this paper is performed exergy analysis of three cylinder steam turbine from the supercritical coal-fired power plant. Exergy analysis parameters were calculated for the whole turbine and each cylinder for the ambient temperature range between 5 °C and 45 °C. The dominant mechanical power producer of all the cylinders is a low pressure cylinder (LPC) which produces 262.06 MW of mechanical power. An increase in the ambient temperature increases exergy destructions and decreases exergy efficiencies of the whole turbine and each cylinder. Exergy analysis shows that LPC is a cylinder with the highest exergy destruction (between 24.67 MW and 28.24 MW) and the lowest exergy efficiency (between 82.27% and 84.16%) in comparison to the other cylinders. Exergy destruction of the whole observed turbine is between 67.85 MW and 77.62 MW, while the whole turbine exergy efficiency ranges between 89.47% and 90.67%. Inside the observed steam turbine, LPC is the most influenced by the ambient temperature change, therefore future research and possible optimization should be specifically based on this cylinder.

In this paper is performed energy analysis of the whole low power steam turbine as well as energy analysis of all the turbine segments. Analysis of the whole turbine resulted with energy loss of 14642.48 kW and energy efficiency of 75.01%, what is in range with similar comparable low power steam turbines. Energy analysis of the turbine segments presents a different conclusion than the energy analysis of the whole turbine. The fifth turbine segment (S5) has unacceptable high energy loss and unacceptable low energy efficiency (energy loss of 6785.93 kW and energy efficiency of 26.87%), so it should be repaired as soon as possible. This comparison sh ow that proper energy analysis of turbine parts (segments) can detect the precise location of the problems during the turbine operation. Such analysis can be very helpful for the engineers because it allows detection not only the problematic components in the power plant, but also allows detection of the problematic parts of a component.

This paper presents a comparison of three methods for any pump energy analysis. Each method is used for the analysis of three different water pumps from the conventional steam thermal power plant – two feed water pumps (FWP1 and FWP2) and condensate pump (CP). For each pump three essential types of mechanical power which defines all energy analysis methods are: delivered power from power producer, real (polytropic) power and ideal (isentropic) power. Method 1 which compares delivered and real (polytropic) power show the best performances, while Method 3 which compare delivered and ideal (isentropic) power should be avoided because it results with too high energy power loss and too low energy efficiency of any pump. Method 2 which compares real (polytropic) and ideal (isentropic) pump power can be used as a good compromise for the pump energy analysis in the most of the cases – its results are similar to results of Method 1.

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.