scholarly journals Evaluation of the efficiency of cavitation-jet deaerator in condensate return systems of remote external consumers of thermal power plants

Vestnik IGEU ◽  
2019 ◽  
pp. 5-13
Author(s):  
Yu.E. Barochkin ◽  
A.Ya. Kopsov ◽  
G.V. Leduhovsky ◽  
S.I. Shuvalov

Thermal power plants (TPPs) operate technological systems for the steam condensate return from remote external consumers. In such systems, it is necessary to protect the metal from corrosion. This will allow ful-filling the regulatory requirements for the concentration of iron compounds in the condensate entering the power plant. Such systems do not use thermal deaerators operated by using heating steam. The aim of the undertaken study is to assess the efficiency of superheated water deaerator use in such conditions, in par-ticular cavitation-jet deaerators. It means determining the effect of a new element of the system – the de-aerator – on the normalized chemical parameters of the returned condensate. A mathematical model of superheated water deaerators is used. The employed model is based on the theory of similarity of heat and mass transfer processes. The methodology for calculating the corrosion rate of return condensate pipelines was used, as well as experimental data on medium pressure TPPs. The efficiency of cavitation-jet deaerators in condensate return systems of external consumers has been estimated. A mathematical description of the system has been developed, which allows determining the required performance of deaerators and the required ratio of water recirculation through them in each mode. Recommendations for effective practical applications of the proposed technical solution have been developed considering the actual conditions at thermal power plants. It is advisable to install a deaerator according to the recirculation scheme through the condensate collection tank. This scheme, compared to a sequential scheme, enables to reduce capital costs and ensure that the deaerator operates in the highest efficiency mode. The choice of the nominal capacity of deaerators should be carried out taking into account the graphs of the change in the flow rate of incoming condensate and the concentration of dissolved oxygen in it during the day. In most operating modes of the system, it is possible to ensure compliance with the regulatory requirements for the mass concentration of corrosion products in the condensate returned to the TPP. The obtained results can be used in the design of new and improving the efficiency of existing TPPs that supply steam to external consumers.

2013 ◽  
Author(s):  
Raj Sekhar Choudhury ◽  
◽  
Sutapa Das ◽  

2020 ◽  
Vol 12 (4) ◽  
pp. 281-285
Author(s):  
A. V. Martynov ◽  
N. E. Kutko

The article deals with the problem of waste disposal and, accordingly, landfills in the Moscow Region, which have now become the number 1 problem for the environment in Moscow and the Moscow Region. To solve this problem, incineration plants (IP) will be established in the near future. 4 plants will be located in the Moscow Region that will be able to eliminate 2800 thousand tons of waste per year. Burning of waste results in formation of slag making 25% of its volume, which has a very high temperature (1300.1500°C). An arrangement is considered, in which slag is sent to a water bath and heats the water to 50.90°C. This temperature is sufficient to evaporate any low-temperature substance (freons, limiting hydrocarbons, etc.), whereupon the steam of the low-temperature working medium is sent to a turbine, which produces additional electricity. The creation of a low-temperature thermal power plant (TPP) increases the reliability of electricity generation at the IP. The operation of low-temperature TPPs due to the heat of slag is very efficient, their efficiency factor being as high as 40.60%. In addition to the efficiency of TPPs, capital costs for the creation of additional devices at the IP are of great importance. Thermal power plants operating on slag are just such additional devices, so it is necessary to minimize the capital costs of their creation. In addition to equipment for the operation of TPPs, it is necessary to have a working medium in an amount determined by calculations. From the wide variety of working media, which are considered in the article, it is necessary to choose the substance with the lowest cost.


2019 ◽  
Vol 12 (1) ◽  
pp. 22-28
Author(s):  
V. Ye. Mikhailov ◽  
S. P. Kolpakov ◽  
L. A. Khomenok ◽  
N. S. Shestakov

One of the most important issues for modern domestic power industry is the creation and further widespread introduction of solid propellant energy units for super-critical steam parameters with high efficiency (43–46%) and improved environmental parameters. This will significantly reduce the use of natural gas.At the same time, one of the major drawbacks of the operation of pulverized coal power units is the need to use a significant amount of fuel oil during start-up and shutdown of boilers to stabilize the burning of the coal torch in the variable boiler operating modes.In this regard, solid fuel TPPs need to be provided with fuel oil facilities, with all the associated problems to ensure the performance (heating of fuel oil in winter), reliability and safety. All of the above problems increase both the TPP capital construction costs, and the electricity generating cost.A practical solution to the above problems at present is the use of a plasma technology for coal torch ignition based on thermochemical preparation of fuel for combustion. The materials of the developments of JSC “NPO CKTI” on application of plasmatrons in boilers of thermal power plants at metallurgical complexes of the Russian Federation are also considered.Plasma ignition systems for solid fuels in boilers were developed by Russian specialists and were introduced at a number of coal-fi red power plants in the Russian Federation, Mongolia, North Korea, and Kazakhstan. Plasma ignition of solid fuels is widely used in China for almost 30% of power boilers.The introduction of plasma-energy technologies will improve the energy efficiency of domestic solid-fuel thermal power plants and can be widely implemented in the modernization of boilers.During the construction of new TPPs, the construction of fuel oil facilities can be abandoned altogether, which will reduce the capital costs of the construction of thermal power plants, reduce the construction footprint, and increase the TPP safety.


Author(s):  
Ye. G. Polenok ◽  
S. A. Mun ◽  
L. A. Gordeeva ◽  
A. A. Glushkov ◽  
M. V. Kostyanko ◽  
...  

Introduction.Coal dust and coal fi ring products contain large amounts of carcinogenic chemicals (specifically benz[a]pyrene) that are different in influence on workers of coal mines and thermal power plants. Specific immune reactions to benz[a]pyrene therefore in these categories of workers can have specific features.Objective.To reveal features of antibodies specifi c to benz[a]pyrene formation in workers of coal mines and thermal power plants.Materials and methods.The study covered A and G class antibodies against benz[a]pyrene (IgA-Bp and IgG-Bp) in serum of 705 males: 213 donors of Kemerovo blood transfusion center (group 1, reference); 293 miners(group 2) and 199 thermal power plant workers (group 3). Benz[a]pyrene conjugate with bovine serum albumin as an adsorbed antigen was subjected to immune-enzyme assay.Results.IgA-Bp levels in the miners (Me = 2.7) did not differ from those in the reference group (Me = 2.9), but in the thermal power plant workers (Me = 3.7) were reliably higher than those in healthy men and in the miners (p<0.0001). Levels of IgG-Bp in the miners (Me = 5.0) appeared to be lower than those in the reference group (Me = 6.4; (p = 0.05). IgG-Bb level in the thermal power plantworkers (Me = 7.4) exceeded the parameters in the healthy donors and the miners (p<0.0001). Non-industrial factors (age and smoking) appeared tohave no influence on specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers.Conclusions.Specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers are characterized by peculiarities: the miners demonstrate lower levels of class A serum antibodies to benz[a]pyrene; the thermal power plant workers present increased serum levels of class G antibodies to benz[a]pyrene. These peculiarities result from only the occupational features, but do not depend on such factors as age, smoking and length of service at hazardous production. It is expedient to study specific immune reactions to benz[a]pyrene in workers of coal mines and thermal power plants, to evaluate individual oncologic risk and if malignancies occur.


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