Power engineering and energy generating technologies

Thermal modeling of the nanosatelliteDeveloped at the NTUU “KPI”

The paper under scrutiny demonstrates numericalsimulation results of thermal modes of the nanosatellitedeveloped at the National Technical University of Ukraine “Kyiv Polytechnic Institute”. It is designedto conduct scientific and applied researchinto the Earth remote sensing in the low Earth orbitwith a solar pointing. In addition, we compare theobtained results with numerical simulation results ofthe “FalconSat-2” small satellite developed by theUnited States Air Force Academy.

The quantitative estimation of the perturbation influence on the fuel burning efficiency

This study considers the problems of the fuel burning efficiency increase in power generating systems and the influence of disturbing factors on fuel-air ratio regulation in the burning process. Emphasized here is the quantitative estimation of an impact of natural gas composition modification and temperature change of air blowing on the fuel combustion efficiency.

Simulation of microsatellite’s thermal modes

We reveal the results of experimental and numerical simulation of thermal modes for microsatellite and provide description of ТВК-2.5 plant for experimental simulation which was created at NTUU “Kyiv Polytechnic Institute”. We describe the calculation procedure of microsatellite’s temperature field and compare the results of experimental and theoreticaland-computational research.

The determination of the local on the heat transfer length at condensation vapor R407C in a horizontal pipe

This paper reports on the influence of mass transfer on local heat transfer on the length of a smooth horizontal pipe at inside condensation mixture R407C. Moreover, we make the calculation of mass transfer component R134А at condensation vapor R407С, taking into account certain assumptions. We illustrate that the presence of the diffusion boundary layer near the surface of condensate film causes the decrease in the intensity of heat transfer at condensation refrigerant R407C on the initial site, comparing with the similar conditions for R22.

Еnergy efficiency of the combined heat pump system of low-temperature water heating and ventilation

The paper deals with the basic scheme of the combined heat pump system of low-temperature water heating – “floor panel heating system” and ventilation. We present the results of еnergy efficiency analysis of this system both taking into account and disregarding the energy expenses for air transportation through the heat pump evaporator.

Fuzzy modeling of a technical condition of high-voltage switches

Based on the theory of fuzzy sets, we elaborate the mathematical model for an integrated estimating of the technical condition as well as for determining the failure probability of various types of highvoltage switches. We also parametrically identify the fuzzy model by utilizing real selections of the technical condition parameters of high-voltage air switches. Finally, we demonstrate that these fuzzy estimation models of switches’ technical condition can be applied in the expert estimating systems of risk decrease of consumer power supply reliability.

Using the opc technology in the automation Of thermal power station units

The paper deals with implementing the OPC technology to increase the operation efficiency of the integrated ACS thermal power station units. We analyze the power generating unit as a technological control object. Specifically, we elaborate the concept of developing the integrated information system of the power generating unit as a part of the grid. We also propose the structure of the typical OPC server which can be used within this concept.

Structure of flow and heat exchange In channels of heatsinkers at cutting Of fins and their turns

This paper highlights the research results of the flow structure (distributors of time-averaged velocities and their fluctuations) and heat exchange for the interfin half-open channels at the optimum depth of cutting (hp/h = 0,6) and the turn of cut parts of ribs on φ = 10...30° angle. Moreover, we substantiate the direct correlation of heat exchange intensification and the growth of total flow disturbances of stream.

Research of stream structure in the intercostals ducting from the surfaces with plate-cutted finning of numeral design methods

The paper under study presents the results of numeral calculations of stream structure in the half-open ducting, formed by split ribs. Through experiments performed, the numeral data is confirmed with sufficiently high accuracy. Moreover, we demonstrate that rib cutting causes the aerodynamic effects of different nature, promoting heat exchange intensifications.