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

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%.

This paper investigates stress state in connection of pipes with flat ends used in pressurized pipelines and steam boiler connections. Flat ends are designed according standard EN 12952-3 and later numerically checked using linear elastic material model. These analyses showed areas with increased stress. Therefore, additional analyses were performed using linear elastic-ideally plastic material. The maximal pressure loads are obtained for series of pipes with flat ends and compared to calculated results according EN 12952-3 norm.

In a companion paper, the response of a two-degrees-of-freedom ship model with nonlinear coupled pitch and roll modes under sinusoidal harmonic excitation was studied analytically by means of the Multiple Scales method for the case where the pitch frequency is twice the roll frequency. Five resonant cases were analysed and the governing equations for the transition towards the steady-state solutions, the first-order approximations for these solutions and the frequency-amplitude relationships were derived. The present contribution aimed to verify the accuracy of the analytical results by contrasting them with the numerical results provided by direct integration of the equations of motion. The two sets of results were found to be in excellent or, at least, in decent agreement every time the system parameters were selected without a flagrant violation of the order’s magnitude.

The paper deals with a design of a regenerator of Stirling engine with unconventional mechanism of engine FIK. The final design of the regenerator is based on previous simulations of flowing of a working fluid, created in software Fluent. The paper presents basic requirements to be followed in the design of the regenerator. The contribution also contains a dimensional computation of the regenerator, which describes basic procedures and boundary conditions in the computation of the designed shape of the regenerator.

In the work a mathematical model for the non-stationary motion of liquid homogeneous viscous mixtures through pipelines is constructed. The corresponding integral equations expressing the laws of conservation of mass, momentum and energy are deriving, from which, in turn, we get the corresponding differential equations. The formulation of the initial and boundary conditions is given; the necessary additional relations that close the corresponding system of differential equations are indicated. A numerical algorithm for solving such a system is proposed. The corresponding numerical examples are given.