The development of a high temperature air heating unit based on the external combustion for integrated gasification combined cycle

The use of heat exchangers in which the working fluid before it enters the gas turbine is warmed up due to the combustion of fuel or other external energy source still is of interest due to the method advantages: the cleanliness of the working fluid; the ability of using cheap low-grade fuels, solar or nuclear energy; the possibility of usage of the closed gas turbine cycle with gases as a working medium, that having favorable thermodynamic properties in comparison with air (helium, CO2, etc.). However, the desired gas turbine inlet temperature - up to 1,700°C currently not possible to provide even with the use of ceramic heat exchangers. Therefore, this technology is now being considered for solid-fuel micro gas turbines operating at temperatures 900-1100°C, or for reducing the need for fuel gas of integrated gasification combined cycle (IGCC) by the means of preheating of cyclic air as well as it is considered for solar gas turbines and gas turbines on the basis of high temperature gas cooled reactors. The authors have developed a metal recuperative air heater based on external combustion of coal for 500 MW IGCC power plant, the development of IGCC is determined by the Energy strategy of Russia for the period up to 2030. In the article the thermal characteristics of the heating of pressurized air, the possible options for the configuration of the heater, heat-resistant materials suitable for its production and the results of the feasibility calculations are considered. In conclusion the design that allows to significantly reduce the specific capital and operating costs for the heater compared to the classic one is proposed. © Published under licence by IOP Publishing Ltd.This work was carried out at the Ural Federal University and financially supported by the Russian Science Foundation (project number 14-19-00524).Comsol;GazEcos;Interenergo;Russian Foundation for Basic Researc

Study of the two-stage gasification process of pulverized coal with a combined countercurrent and concurrent flow system

The paper presents a numerical study of an advanced two-stage gasifier with a combined countercurrent and concurrent flow pattern and dry fuel feed system EAGLE. The Reynolds Stress model was used for the numerical simulation of turbulent flow. We have conducted studies on the influence of upper burner's inclination angle on heat and mass transfer processes in the gasifier as well as on coal conversion. It is shown that the increase in the upper burner's inclination angle in the horizontal plane allows intensifying the process of two-stage gasification. © 2017 The Authors, published by EDP Sciences.Problem statement and results analysis were carried out at the Ural Federal University and financially supported by the Russian Science Foundation (project no. 14-19-00524). The development of methods for mathematical modeling and calculations was carried out with the financial support of the Ministry of Education and Science of the Russian Federation under the Grant Agreement No. 14.607.21.0150 (Unique identifier of the RFMEFI60716X0150

Experimental and computational study and development of the bituminous coal entrained-flow air-blown gasifier for IGCC

In the paper the development of the advanced bituminous coal entrained-flow air- blown gasifier for the high power integrated gasification combined cycle is considered. The computational fluid dynamics technique is used as the basic development tool. The experiment on the pressurized entrained-flow gasifier was performed by "NPO CKTI" JSC for the thermochemical processes submodel verification. The kinetic constants for Kuznetsk bituminous coal (flame coal), obtained by thermal gravimetric analysis method, are used in the model. The calculation results obtained by the CFD model are in satisfactory agreements with experimental data. On the basis of the verified model the advanced gasifier structure was suggested which permits to increase the hydrogen content in the synthesis gas and consequently to improve the gas turbine efficiency. In order to meet the specified requirements vapor is added on the second stage of MHI type gasifier and heat necessary for air gasification is compensated by supplemental heating of the blasting air. © Published under licence by IOP Publishing Ltd.This work was financially supported by the Russian Science Foundation (project no. 14-19-00524)

Technical and economical evaluation of a high-temperature air heater intended for integrated gasification combined cycle unit

In this paper the costs of creating a high-temperature air heater intended for the integrated gasification combined cycle unit developed by the authors are estimated and are compared with a steam boiler. The results can be used not only in the further development of the integrated gasification combined cycle plant under consideration, but also be interesting to specialists involved in the development of various high-temperature heat exchangers. © 2020 Institute of Physics Publishing. All rights reserved.The study was financially supported by the Russian Foundation for Basic Research (No. 14-08-01226)

Selecting the design of a high-temperature air heater for integrated gasification combined cycle

High temperature heat exchangers are needed in various energy technologies to increase their efficiency. The article is devoted to the optimization of the design of a high-temperature air heater used in the integrated gasification combined cycle plant, developed in Ural Federal University. In the air heater, air with a pressure of 2 MPa after the cycle compressor is heated by coal combustion to a temperature of 900°C before it is fed into the combustion chamber of a gas turbine. The air heater is developed as a pulverized coal fired boiler with air heating in tubular radiation-convection heating surfaces. The authors propose a new design of a high-temperature air heater, which allows reducing the cost of the expensive high-temperature part of the unit 1.8 times compared with the previous design. A computer simulation of the boiler section is carried out to verify the proposed design solutions. © Published under licence by IOP Publishing Ltd

Polarimetric radar observations and interpretation of co-cross-polar correlation coefficients

Includes bibliographical references (page 354).Preliminary analysis of all components of the polarimetric radar covariance matrix for precipitation measured with the NCAR S-band dual-polarization Doppler radar (S-Pol) and the Colorado State University-University of Chicago-Illinois State Water Survey (CSU-CHILL) radars is presented. Radar reflectivity at horizontal polarization Zh, differential reflectivity ZDR, linear depolarization ratio LDR, specific differential phase KDP, crosscorrelation coefficient | ρhv | , and two co-cross-polar correlation coefficients, ρxh and ρxv, have been measured and examined for two rain events: the 14 August 1998 case in Florida and the 8 August 1998 case in Colorado. Examination of the coefficients ρxh and ρxv is the major focus of the study. It is shown that hydrometeors with different types of orientation can be better delineated if the coefficients ρxv and ρxv are used. Rough estimates of the raindrop mean canting angles and the rms width of the canting angle distribution are obtained from the co-cross-polar correlation coefficients in combination with other polarimetric variables. Analysis of the two cases indicates that the raindrop net canting angles averaged over the propagation paths near the ground in typical convective cells do not exceed 2.5°. Nonetheless, the mean canting angles in individual radar resolution volumes in rain can be noticeably higher. Although the net canting angle for individual convective cells can deviate by a few degrees from zero, the average over a long propagation path along several cells is close to zero, likely because canting angles in different cells vary in sign. The rms width of the canting angle distribution in rain is estimated to vary mainly between 5° and 15° with the median value slightly below 10°

Development of low-temperature thermochemical conversion reactors for coal power engineering

The main principles applied in developing a technology for low-temperature thermochemical conversion of brown coals to obtain fuel gas and semicoke intended for being fired in two-fuel power installations are considered on the basis of a set of experimental and calculated investigations. The obtained results are compared with the experimental data obtained using other methods and with the results of previous industrial tests. © 2013 Pleiades Publishing, Inc

Extraorganic Hepatic Artery Aneurysm: Failure of Transcatheter Embolization

Hepatic artery aneurysm (HAA) was diagnosed in a 62-year-old man who was a poor candidate for surgery because of severe liver cirrhosis and diabetes mellitus. Two attempts to occlude the HAA by transcatheter embolization failed because of recanalization of the aneurysm. Moreover, aneurysmal dilatation of the superior mesenteric artery and the left renal artery developed and progressed. Both the literature and the present case show that an individual approach to treatment of extraorganic HAA should be chosen in dependantan location and anatomy of the lesion

Improvement of the Procedure for Sanitary and Quarantine Control of Ships in the Seaports

Objective of the work is to analyze the procedure of ship sanitary and quarantine control in the Rostov Region seaports in order to identify the risks for sanitary and epidemiological welfare of the population and to improve communication process between the authorized ports. Materials and methods. Ship sanitary and quarantine control data on 8314 ships that arrived at Rostov-on-Don, Azov and Taganrog sea border checkpoints were used, considering possible risks for the sanitary and epidemiological welfare of the population. Results and conclusions. The key risks for decision-making whether to perform ship sanitary and quarantine control at the sea border checkpoints are identified. At the stage of the implementation of IHR (2005) it is necessary to consider the ship sanitary and quarantine control at the sea border checkpoints as an unscheduled inspection; availability of preliminary information on the absence of valid sanitary certificates on ships arriving from abroad to be the ground for carrying out ship sanitary and quarantine control at the sea border checkpoints. In order to improve the communication process between authorized ports it is necessary to insert the results of the inspections into ship’s sanitary certificates with issuance of the revealed risks forms

The comparative study of selective laser trabeculoplasty effectiveness in phacic and pseudophacic patients with glaucoma

Purpose: To compare the effect of selective laser trabeculoplasty (SLT) in phacic and pseudophacic patients with glaucoma.Methods: A retrospective chart review was performed on 148 eyes of 139 patients with moderate primary open angle glaucoma (POAG). In the first group (pseudophacic group) 50 patients (50 eyes) underwent SLT at the period of 6 months and more after uneventful phacoemulsification cataract surgery, in the second (phacic group: 9 patients, 98 eyes) — 2‑3 months prior it. The post-laser follow up examinations were carried out at 1 day, 1 week, 1 month, 6 months and 12 months of follow-up. Average intraocular pressure (IOP), its decrease, and MD — mean deviation perimetric index — for phakic and pseudophakic eyes were compared statistically at each time period. A t-test was used to compare the IOP reduction between the phakic and pseudophakic groups.Results: IOP reduction in the pseudophakic group was statistically significant in the 1 month of follow up (from 28.3 mm Hg to 18.6mm Hg, p = 0.02), while in the phacic group its reduction was statistically significant in all steps of observation. The statistically significantdifference of IOP decrease level between groups was obtained in 1 week and 1 year after SLT. The MD perimetric index decreased by 3.89 dB (from –7.63 to –11.52) in the pseudophakic group and increased by 0.65 dB (from –4.31 to –3.66) in the phakic group.Conclusion: SLT is a safe and effective means of IOP reduction in pseudophakic glaucoma patients. However it seems to be more effective in lowering IOP if performed prior to cataract surgery: effect of SLT in pseudophakic eyes reduced through 6 months. SLT performed on phakic eyes might play a role in visual field improvement