Investigation of thermal processes in hydrogen-oxygen steam generators of kilowatt power class

PURPOSE. Testing of a hydrogen-oxygen steam generator (HOSG) of the kilowatt power class for the study of heat and mass transfer processes. METHODS. At the first stage, the technological system of diagnostics and control was considered, with the help of which preliminary tests were carried out. According to the results of which the structural elements of the HOSG were modernized. Further, at the second stage, an automated process control system was created, which ensured the conduct of multi-mode tests of the HOSG. RESULTS. The design of the HOSG showed its efficiency. The changes in the cooling water flow rate, pressure and temperature in the evaporation chamber during multi-mode tests are presented, as well as the generalized results of experimental studies, which show the dependence of the steam temperature on the mass fraction of water at different coefficients of the excess oxidizer.CONCLUSION. During the preliminary tests, the development of upgraded components of the HOSG was carried out, ensuring an increase in the efficiency of its operation. The created automated control system made it possible to successfully conduct subsequent multi-mode tests with two different types of cameras. The indicators of unreacted hydrogen are comparable to those already achieved in existing devices. The characteristic transition times from mode to mode show compliance with the requirements for creating autonomous power plants based on renewable energy sources.

A Phase Separation Inlet for Droplets, Ice Residuals, and Interstitial Aerosol Particles

A new inlet for studying the aerosol particles and hydrometeor residuals that compose mixed-phase clouds – the phaSe seParation Inlet for Droplets icE residuals and inteRstitial aerosol particles (SPIDER) – is described here. SPIDER combines a Large-Pumped Counterflow Virtual Impactor (L-PCVI), a flow tube evaporation chamber, and a Pumped Counterflow Virtual Impactor (PCVI) to separate droplets, ice crystals, and interstitial aerosol particles for simultaneous sampling. Laboratory verification tests of each individual component and then the composite SPIDER system were conducted. SPIDER was then deployed at Storm Peak Laboratory (SPL), a mountain-top research facility at 3210 m a.s.l. in the Rocky Mountains. SPIDER performance as a field instrument is presented with data that demonstrates its capability of separating cloud elements and interstitial aerosol particle. Possible design improvements of SPIDER are also suggested.

Finite Element Analysis of An Evaporation System to Synthesize Kesterite thin Films

Currently, there is an interest within the scientific community in thin-film solar cells with a Kesterite (Cu2ZnSnS4) type absorber layer, since they report a theoretical efficiency greater than 32 %. The synthesis of Kesterites by evaporation has allowed for efficiencies at the laboratory level of 11.6 %. Although these are good results, the design of the evaporation chamber and the distribution of the electrodes is essential to control synthesis parameters and evaporate each precursor in the corresponding stage. This project seeks to design an evaporation chamber that can achieve a vacuum of 10-5 mbar, increase the deposition surface and avoid each precursor evaporation in a non-corresponding stage. This last objective was studied using Comsol multiphysics R. (licensed product) software, with the adequate disposition of metallic precursors (zinc, copper, and tin) determined by analyzing heat distribution. It was concluded that the lower the evaporation temperature of the precursor, the smaller the height of the copper electrode in the system. This is because, with a lower height the concentration of heat in the container is lower.

A Phase Separation Inlet for Droplets, Ice Residuals, and Interstitial Aerosols

A new inlet for studying the aerosols and hydrometeor residuals that compose mixed-phase clouds – the phaSe seParation Inlet for Droplets icE residuals and inteRstitial aerosols (SPIDER) – is described here. SPIDER combines an omni-directional inlet, a Large-Pumped Counterflow Virtual Impactor (L-PCVI), a flow tube evaporation chamber, and a Pumped Counterflow Virtual Impactor (PCVI) to separate droplets, ice crystals, and interstitial aerosols for simultaneous sampling. Laboratory verification tests of each individual component and the composite SPIDER system were conducted. SPIDER was deployed to Storm Peak Laboratory (SPL), a mountain-top research facility at 3210 m a.s.l. in the Rocky Mountains, for a three-week field campaign. SPIDER performance as a field instrument is presented with data that demonstrates its capability of separating distinct cloud elements and interstitial aerosol. Possible design improvements of SPIDER are also suggested.

SOLAR WATER SEA DISTILLATION USING CONDENSER

Water is one of the main needs of living things, especially humans who need clean water for drinking, bathing, washing and other purposes. However, many regions have difficulties to get clean water, especially people who live on the beach, thus many experts try to process seawater into clean water which is worth drinking. One of the ways to process salt water into fresh water is by distillation. In this research, the author tries to distill water with the help of condenser. In this research, the author made an evaporation chamber of 80 cm x 100 cm x 30 cm. Through the use of solar-powered blower, vapor is inhaled from the evaporation chamber, therefore the pressure on the evaporation chamber will fall, so that the evaporation will occur much faster and the resulting vapor can be supplied to the condenser for cooling. From the test result using variation of blower rotation of 2800 rpm, 2200 rpm, and 1200 rpm, each condensate water produced from the distillation process are 215 ml/h, 410 ml/h, and 250 ml/hr. The condensate resulted from the highest rotation (2800 rpm) produces less condensate, thus based on our observation, we temporarily conclude that it occurs because there is water vapor coming out from the condensate, but more accurate research is needed to confirm it. Condensate of 410 ml/hour is still not as expected, thus this research will be continued in order to reach the expected result.

ЧИСЕЛЬНЕ МОДЕЛЮВАННЯ ПРОТОЧНОЇ ЧАСТИНИ МАЛОВИТРАТНОГО АЕРОТЕРМОПРЕСОРА ДЛЯ ПРОМІЖНОГО ОХОЛОДЖЕННЯ ЦИКЛОВОГО ПОВІТРЯ ГАЗОТУРБІННОГО ДВИГУНА

A cyclic air intercooling application in the compression process in the compressor has a positive effect on the resource of the gas turbine plant (GTP) and on increasing its capacity without reducing the service life. The most promising method of cooling the cyclic air of the GTP, namely contact cooling by using an aerothermopressor, was analyzed in the paper. This heat exchanger is a two-phase jet apparatus in which, due to the removal of heat from the airflow, the air pressure is increased and its cooling occurs. The main problem in the development of the aerothermopressor is to determine the geometric characteristics of the apparatus flow part and the fluid injection system, which allow its effective application for increasing pressure and fluid spraying fine. An analysis was made of the apparatus models operation by using CFD simulation in the ANSYS Fluent software package to determine the aerothermopressor main characteristics of the cyclic air cooling system of the GTP. The calculation method was determined, the turbulence model was selected, the calculation was carried out taking into account the convergence of the results, and the output data were processed and visualized in the CFD-Post in the form of graphs and fields. Based on this, the aerothermopressor design was developed for a WR-21 gas turbine produced by Rolls Royce. At the first stage of the study, a “dry” aerothermopressor was modeled (without water injection into the evaporation chamber). It was found that the decrease in airflow pressure due to friction losses was about 5%. At the second stage of the study, a simulation of the aerothermopressor with water injection into the flow part (at the inlet to the evaporation chamber) was carried out. As a result of thermogasdynamic compression, the increase in the total air pressure at the outlet of the aerothermopressor was 3.1%, and the temperature of the cooled air was decreased by 280 degrees. To ensure effective air compression in the gas turbine compressor, incomplete evaporation of water in the aerothermopressor was considered. It made it possible to obtain finer water spraying at the diffuser outlet, while the average diameter of the water droplet decreased to 2.5 μm.

Stages of scientific and applied activities of the department of external processing of the iron of ISI NANU

The history of the creation and development of the research unit of the Iron and Steel Institute, the department of after-furnace treatment of cast iron is presented. From 1939 to 1983, this structural unit of the ISI was headed by Doctor of Technical Sciences, Professor Natalya Aleksandrovna Voronova, then for 34 years, until 2017, the student and associate of N.A. Voronova – Doctor of Technical Sciences, Professor Shevchenko A.F., from 2017 to the present, the department is headed by Kislyakov V.G. During this period, a set of scientific research and development has provided an opportunity for the department staff to defend 3 doctoral and 16 master's theses. Two employees of the department were awarded the academic title of professor, and ten – senior research assistant. The evolution of the technological process and equipment for the processing of cast iron by granular magnesium in ladles of various capacities is shown. In particular, it was not possible to inject granular magnesium without additives with lances used to inject mixtures of magnesium with fillers into the melt due to blockage of the channel of the magnesium wire at the outlet of the lance. To solve this problem, a lance of a new design was developed, at the outlet of the channel of which an evaporation chamber was installed, the task of which was to remove the section of the lance channel from direct contact with cast iron. The design of tuyeres with evaporation chambers made it possible to virtually eliminate blockages of the tuyere channel. The studies of the interaction of magnesium with molten iron became the scientific basis for the creation of a modern highly automated process for the secondary refining of cast iron by mono-injection of magnesium without additives. This technology received the most successful application in the creation of modernized complexes at Chinese enterprises. Since 2001, 84 complexes of out-of-furnace desulphurization of pig iron and slag download using ISI technology with a total capacity of over 100 million tons/year of low-sulfur and pig iron-free slag have been built and commissioned at 39 plants in China.