scholarly journals THERMOELECTRIC SYSTEM FOR EXTRACTION OF FOREIGN OBJECTS FROM HUMAN BODY

2019 ◽  
Vol 46 (1) ◽  
pp. 32-41
Author(s):  
O. V. Evdulov ◽  
S. G. Magomedova ◽  
I. Sh. Mispahov ◽  
N. A. Nabiyev ◽  
A. M. Nasrulaev
Keyword(s):  
Human Body ◽  
Power Plants ◽  
Thermal Power ◽  
Thermoelectric Module ◽  
External Source ◽  
Cooling Capacity ◽  
Layer Growth ◽  
Cold Surface ◽  
Foreign Objects ◽  
Medical Standards

Objectives. The purpose of the article is to examine the design of the thermoelectric system (TPP) for the extraction of foreign objects from the human body by the method of freezing, as well as the simulation of heat transfer processes in it.Method. A design and a physical model of the system for the extraction of foreign objects from the human body are proposed, in which the source of cold is a thermoelectric module (TEM) placed on a special mechanical device made in the form of a probe, which also provides removal of heat from the hot junctions of the module. A mathematical model of thermal power plants was developed, implemented on the basis of solving the problem of ice layer growth using the method of solving the non-stationary Fourier differential equation, presented in partial derivatives by reducing it to an equation with full derivatives based on the use of an extended version of the Lame-Clapeyron substitution, and power series, which describes the temperature distribution in the frozen ice layer and satisfies the boundary conditions of the problem.Result. Data were obtained on the change in temperature of the extracted object and the thickness of the ice layer over time at various values of the cooling capacity of TEM. It is established that the duration of the formation of an ice layer between the object to be extracted and the cold surface of the TEM, which is the executive element of the system, is within narrow limits that meet medical standards, while the speed of the ice growth process depends on its thickness (increasing the cooling capacity of the TEM from 1000 to 3000 W / m2 reduces the duration of the formation of an ice layer, 2 mm thick, by almost 40 s, while the temperature of the extracted object decreases from 269 K to 252 K). It is indicated that the selection of geometric parameters of TEM and its power supply should focus on the limitations on the operation of the device, as well as medical norms and standards in order to avoid the process of frostbite of the adjacent tissues.Conclusion. A method is proposed for increasing the efficiency of the system, according to which the preliminary cooling of the TPP by an external source of cold is used, as well as the use of forced TEM operation modes.

scholarly journals Temperature field of a thermoelectric system for extracting foreign objects when introducing into the human body

2021 ◽  
Vol 47 (4) ◽  
pp. 27-36
Author(s):  
O. V. Evdulov ◽  
A. M. Nasrulaev
Keyword(s):  
Human Body ◽  
Thermoelectric Module ◽  
Cooling Capacity ◽  
Design Model ◽  
Foreign Object ◽  
Temperature Changes ◽  
Foreign Objects ◽  
Cold Source ◽  
External Conditions ◽  
System Mode

Objective. The objective of the article is to create a design model of a thermoelectric system for extracting foreign objects from the human body by freezing when introduced into the cavity, as well as to study the internal thermophysical processes.Methods. A design model of a thermoelectric system for extracting foreign objects from the human body by freezing the thermoelectric system introduced into the cavity is developed, based on solving the problem of thermal conductivity, taking into account the thermophysical characteristics of a biological object, foreign object, and a thermoelectric module.Results. As a result of the numerical experiment, the authors obtained graphs of temperature changes at various points of the thermoelectric system when introduced into the human body to extract a foreign object, depending on the power of the thermoelectric system, the parameters of the module materials, and external conditions. It is determined that the device can use a standard thermoelectric module with a cooling capacity from 4500 W/m2 to 7000 W/m2 with a duration of 6-7 minutes for entering the system mode.Conclusion. It is established that the selection of thermoelectric module parameters must be guided by the limitations of the device operation, as well as medical norms and standards to avoid the process of cold injury of adjacent tissues, which is fully provided in the proposed design. A method for improving the efficiency of the system is proposed, according to which the thermoelectric system is pre-cooled using an external cold source, and forced modes of thermoelectric module operation are used.

scholarly journals Design of thermoelectric devices for extracting foreign objects from the human body by freezing

2021 ◽  
Vol 48 (3) ◽  
pp. 16-25
Author(s):  
O. V. Evdulov ◽  
A. M. Nasrulaev ◽  
R. Sh. Kazumov
Keyword(s):  
Human Body ◽  
Thermoelectric Module ◽  
Heat Removal ◽  
Operating Conditions ◽  
Heat Output ◽  
Thermoelectric Devices ◽  
Foreign Objects ◽  
Heat Removal System ◽  
Radiator System ◽  
Removal System

Objectives.The  purpose  of  the  article  is  to  consider  the  designs  of thermoelectric  devices  (TEC)  for  extracting  foreign  objects  (IO)  from  the  human  body  by freezing with various options for removing heat from the hot junctions of the thermoelectric module (TEM).Method. Modifications of thermoelectric devices are described for extracting the IO from the human body by freezing it to a special probe. Their technical design differs in the way of heat removal from the TEM hot junctions, for which air heat removal, melting working substances and preliminary cooling of the radiator are used. The basic relationships for calculating the technical means intended for the removal of heat from the hot junctions of the TEM are presented.Result. The graphs of the dependence of the temperature change of the TEM hot junctions in time are obtained for different values of its heat output when using an air heat removal system and the time of complete penetration of various working substances used in the device.Conclusion. The data obtained show that for the operating conditions of the TEC, the temperature of the hot junctions of the TEM with an air heat sink does not go beyond the permissible limits. With a module power of 8 W, 12 W and 16 W, the temperature of the hot junctions of thermoelements stabilizes rather quickly and takes the value of 308 K, 313 K and 318 K. maintaining their stable temperature is most preferred is nickel nitrate, less - elaidic acid and paraffin. Calculations of the design of a device with a pre-cooled radiator system also show the efficiency of heat removal from the hot junctions of the TEM for the duration of the entire procedure for removing the IO from the human body.

A Review on Utilization of Fly- Ash and Pond-Ash as a Partial Replacement of Cement in Concrete Mix Design

2018 ◽  
pp. 413-418
Author(s):  
Harshkumar Patel ◽  
Yogesh Patel
Keyword(s):  
Fly Ash ◽  
Electricity Generation ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Thermal Power ◽  
Strength Test ◽  
Partial Replacement ◽  
Pond Ash ◽  
Research Activities ◽  
Ash Disposal

Now-a-days energy planners are aiming to increase the use of renewable energy sources and nuclear to meet the electricity generation. But till now coal-based power plants are the major source of electricity generation. Disadvantages of coal-based thermal power plants is disposal problem of fly ash and pond ash. It was earlier considered as a total waste and environmental hazard thus its use was limited, but now its useful properties have been known as raw material for various application in construction field. Fly ash from the thermal plants is available in large quantities in fine and coarse form. Fine fly ash is used in construction industry in some amount and coarse fly ash is subsequently disposed over land in slurry forms. In India around 180 MT fly is produced and only around 45% of that is being utilized in different sectors. Balance fly ash is being disposed over land. It needs one acre of land for ash disposal to produce 1MW electricity from coal. Fly ash and pond ash utilization helps to reduce the consumption of natural resources. The fly ash became available in coal based thermal power station in the year 1930 in USA. For its gainful utilization, scientist started research activities and in the year 1937, R.E. Davis and his associates at university of California published research details on use of fly ash in cement concrete. This research had laid foundation for its specification, testing & usages. This study reports the potential use of pond-ash and fly-ash as cement in concrete mixes. In this present study of concrete produced using fly ash, pond ash and OPC 53 grade will be carried. An attempt will be made to investigate characteristics of OPC concrete with combined fly ash and pond ash mixed concrete for Compressive Strength test, Split Tensile Strength test, Flexural Strength test and Durability tests. This paper deals with the review of literature for fly-ash and pond-ash as partial replacement of cement in concrete.

Improving the efficiency and reliability of electric power generation at incineration plants

2020 ◽  
Vol 12 (4) ◽  
pp. 281-285
Author(s):  
A. V. Martynov ◽  
N. E. Kutko
Keyword(s):  
Low Temperature ◽  
Power Plants ◽  
Thermal Power ◽  
Moscow Region ◽  
Capital Costs ◽  
Working Medium ◽  
The Creation ◽  
Working Media ◽  
Near Future ◽  
Efficiency And Reliability

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.

On the prospect of introduction of plasma ignition in power boilers

2019 ◽  
Vol 12 (1) ◽  
pp. 22-28
Author(s):  
V. Ye. Mikhailov ◽  
S. P. Kolpakov ◽  
L. A. Khomenok ◽  
N. S. Shestakov
Keyword(s):  
Russian Federation ◽  
Solid Fuel ◽  
Power Plants ◽  
Thermal Power ◽  
Fuel Oil ◽  
Solid Fuels ◽  
Thermal Power Plants ◽  
Plasma Ignition ◽  
The Russian Federation ◽  
Capital Construction

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.

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