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

In this paper are presented results of a low-pressure steam turbine energy and exergy analysis during turbine extractions opening/closing. All possible combinations of extractions opening/closing are observed. The highest mechanical power which can be produced by this turbine (when all steam extractions are closed) is 28017.48 kW in real and 31988.20 kW in an ideal situation. For all observed steam extractions opening/closing combinations is obtained that energy efficiency and energy losses range is relatively small (from 87.56% to 87.94% for energy efficiency and from 3360.46 kW to 3970.72 kW for energy losses). Trends in energy and exergy losses (destructions) are identical for all observed extractions opening/closing combinations. Analyzed turbine efficiencies (both energy and exergy) will decrease for a maximum 1% during the steam extractions closing. Turbine steam extractions closing decrease turbine efficiencies and increases turbine losses (destructions), what is valid from both energy and exergy aspects.

This paper presents an analysis and comparison of three steam turbines and its cylinders: from the conventional steam power plant, from nuclear power plant and from the marine propulsion plant. The best parameters for the comparison of whole turbines and its cylinders are: energy loss per unit of produced mechanical power, exergy destruction per unit of produced mechanical power, energy efficiency and exergy efficiency. Steam turbine from marine propulsion plant shows the worst performance, regardless if observing each cylinder or the whole turbine – it has the highest losses per unit of produced mechanical power and the lowest efficiencies (both energy and exergy). Such results can be explained by a fact that marine steam turbine must be much more dynamic in operation in comparison to other two turbines. Also, marine steam turbine analyzed in this paper did not possess steam reheating between the cylinders as the other two observed steam turbines, what has a dominant impact on the obtained results.

The paper presents a thermodynamic analysis of gas turbine with real open cycle. Gas turbine operates in combined heat and power (CHP) system. Analysis is provided by using measured operating parameters of operating mediums (air and combustion gases) in all required operating points. Cumulative real turbine developed power amounts 78611.63 kW. In the whole gas turbine process, the highest losses occur in combustion chambers during the heat supply process and amounts 13689.24 kW. Turbine power losses are equal to 7976.22 kW, while the turbo-compressor power losses amounts 4774.24 kW. While taking into account all analyzed gas turbine components, the highest efficiency of 90.79% has turbine, followed by combustion chambers which efficiency is equal to 89.01%. Turbo-compressor efficiency amounts 88.59% and the whole gas turbine cycle has efficiency equal to 33.15%.

The paper presents a thermodynamic analysis of gas turbine with real open cycle. Gas turbine operates in combined heat and power (CHP) system. Analysis is provided by using measured operating parameters of operating mediums (air and combustion gases) in all required operating points. Cumulative real turbine developed power amounts 78611.63 kW. In the whole gas turbine process, the highest losses occur in combustion chambers during the heat supply process and amounts 13689.24 kW. Turbine power losses are equal to 7976.22 kW, while the turbo-compressor power losses amounts 4774.24 kW. While taking into account all analyzed gas turbine components, the highest efficiency of 90.79% has turbine, followed by combustion chambers which efficiency is equal to 89.01%. Turbo-compressor efficiency amounts 88.59% and the whole gas turbine cycle has efficiency equal to 33.15%.

Described in the scientific literature the results of experimental studies and performance test of the technological process of sugar beet harvesting conducted in recent years have shown that modern sugar-beet harvesters manufactured in Europe and America work with significant losses of sugar-bearing plant materials. These losses are due to generally poor topping quality of sugar beet on a root. Therefore, nowadays the search of technical solutions enabling to avoid these losses is of great to importance as it increases the yield of sugar-bearing plant materials per hectare of crops. The purpose of research is to reduce the losses of sugar-bearing plant materials in the course of separation process of sugar beet tops from heads of root crops on a root. While conducting research the methods of field experimental research on the measurement of physical parameters of the technological process were used, as well as methods of statistical processing of the measurement results with the use of computer. New experimental equipment was designed for the field experimental studies being equipped with modern electronic equipment with data transfer to a PC. As a result of the experimental investigation of the distribution heads heights above the ground of sugar beet roots confirmation has been received hypothesis that it does not deny the law of the normal distribution. The results of the multiple measurements enabled set limits of changes in their statistical characteristics, which are as follows: average statistical deviation σ = 20 … 30 mm, the expectation m = 40 … 60 mm. A new design of the laboratory equipment and results of the experimental studies, conducted on it, have given every reason to design and develop a new system of automatic adjustment of the height of cut tops, which can be used in designs of modern sugar-beet harvesting machines.

Described in the scientific literature the results of experimental studies and performance test of the technological process of sugar beet harvesting conducted in recent years have shown that modern sugar-beet harvesters manufactured in Europe and America work with significant losses of sugar-bearing plant materials. These losses are due to generally poor topping quality of sugar beet on a root. Therefore, nowadays the search of technical solutions enabling to avoid these losses is of great to importance as it increases the yield of sugar-bearing plant materials per hectare of crops. The purpose of research is to reduce the losses of sugar-bearing plant materials in the course of separation process of sugar beet tops from heads of root crops on a root. While conducting research the methods of field experimental research on the measurement of physical parameters of the technological process were used, as well as methods of statistical processing of the measurement results with the use of computer. New experimental equipment was designed for the field experimental studies being equipped with modern electronic equipment with data transfer to a PC. As a result of the experimental investigation of the distribution heads heights above the ground of sugar beet roots confirmation has been received hypothesis that it does not deny the law of the normal distribution. The results of the multiple measurements enabled set limits of changes in their statistical characteristics, which are as follows: average statistical deviation σ = 20 … 30 mm, the expectation m = 40 … 60 mm. A new design of the laboratory equipment and results of the experimental studies, conducted on it, have given every reason to design and develop a new system of automatic adjustment of the height of cut tops, which can be used in designs of modern sugar-beet harvesting machines.

Harvesting rain-fed chickpeas (Cicer arietinum L.) from fallow fields in developing countries is currently a manual process performed by laborers in a tedious manner at a low level of efficiency. A tractor-pulled harvester was built in which a chain conveyor transfer harvested material. A tractor-mounted harvester was then redesigned, which incorporated a modified stripper header to detach pods from the anchored plants together with a pneumatic conveyor mechanism. The resulting machine benefitted from being light-weight and having good maneuverability. Reduction of total losses from over 50% to close to 25% over a seven-year period confirms the potential of the prototype for commercialization.