CC BY
11УДК 621.313.33; 621.45.034
Toirov O.Z.
Doctor of Technical Sciences, Professor Head of Department "Electrical Machines" Tashkent State Technical University (Uzbekistan, Tashkent)
Shatursunov Sh.Sh.
Master Student of the Department "Electrical Machines" Tashkent State Technical University (Uzbekistan, Tashkent)
Akberdiev M.A.
Master Student of the Department "Electrical Machines" Tashkent State Technical University (Uzbekistan, Tashkent)
INCREASING THE EFFICIENCY OF THE LIQUID FUEL COMBUSTION CHAMBER OF THE
WIRE ANNEALING FURNACE DUE TO THE ADJUSTABLE ELECTRIC DRIVE
Abstract: this article discusses the issue of regulating the air supply by means of an adjustable electric drive, and ensuring optimal combustion of fuel depending on the volume of gaseous fuel, thereby increasing the efficiency of the chamber. Optimal control of combustion of gaseous fuel.
Key words: electric drive, optimality, fuel, gas, combustion chamber, component.
The desire to ensure high energy efficiency of industrial plants and technological complexes, as well as the need to ensure the required parameters of technological processes, have been a catalyst for the development and widespread use of controlled electric drive systems, among which the frequency-controlled electric drive has become the most widely used [1-5]. When choosing and implementing an electric drive system, one should take into account a number of factors that affect the technical and economic indicators of the feasibility of using a particular electric drive system [6-8].
The object of control is the combustion chamber: the fuel enters the combustion chamber, which consists of a mixture of combustible gases H (hydrogen), CO (carbon monoxide), CH4 (methane), in the following proportions 2% hydrogen, 18% carbon monoxide, 80% - methane [2].
Let us assume the maximum fuel consumption Gt=0,5 kg/s. During fuel combustion, each component has its own calorific value XCH=11000 kcal/kg, Xco=2400 kcal/kg, Xn=3000 kcal/kg. Air contains 23% oxygen.
We define the static characteristic of the combustion chamber, that is, the dependence:
Q=f(Ge)
Solution of the task:
Let us determine the calorific value of 1 kg of fuel in accordance with Xt=X^0,02+Xch4^0.8+Xco-0,18=30008-0,02+11000-0,8+2400-0,18=9292 kcal/kg
i.e. Xt-9300 kcal/kg.
Next, we determine the amount of air required for the complete combustion of 1 kg of fuel, for which we write the combustion reaction:
For hydrogen 2H2 + O2 = H2O or 4kg + 32kg = 36kg, that is, 8 kg of oxygen is required to burn 1kg of hydrogen.
For carbon monoxide 2CO + O2 = 2CO2 or 56kg + 32kg = 88 kg, that is, for the combustion of 1kg of carbon monoxide, 4/7kg of oxygen is required.
For methane CH4 + 2O2 = CO2 + 2H2O or 16kg + 64kg = 44kg + 36kg, that is, 4 kg of oxygen is required to burn 1kg of methane.
The total amount of oxygen required for the oxidation of combustible gases Po=8H + 4 / 7CO + 4CH4 substituting numerical values, we determine the quantitative value:
Po=8 • 0,02+4/7 • 0,18+4 • 0,8=3,46 kg. Calculate the amount of air containing 3.46 kg of oxygen PB=P0 / 0.23 since the air contains 23% oxygen, substituting the values we get:
Pb=P0/0,23=3 ,46/0,23~15kg The calculation of the static characteristics of the combustion chamber Q=f(GB) will be carried out in accordance with equation (1)
Q=(Gr At+Gb • Cb • QB+Gr Cr Qt)/ (Gt+Gb) • C (1)
where GT is the amount of fuel, GB is the amount of air, QB, QT - temperature of air, fuel when supplied to the combustion chamber. Having made some assumptions that will not fundamentally affect the form of the static characteristic. We neglect the term GT-CrQT, that is, the amount of heat that is introduced with the fuel. At a constant fuel consumption, this term is constant and small compared to the GT^At term. Further, we assume that C does not depend on the temperature and pressure in the combustion chamber, that is, C=const, C=0.23 in the entire temperature range of the combustion chamber. Then the formula takes the form:
Q=(GrAT+ Gb-C-Qb)/( Gt+Gb)•C (2)
substituting the values of the constants Cb^Qb, the formula takes the form:
Q=(Gt • At+Gb • 0,23 • 20)/(Gt+Gb) • 0,23 Since Gr A will depend on GB until GB=7.5kg/s, then formula (2) will take the form in the range 0< Gb<7.5 will take the form as Gt=Gb/15
Q=(Gb/15-At + Gb-0,23-20)/( Gt+Gb)• 0,23=624.6 Gb/( Gt+Gb) ^0,23 And for GB>7.5 kg/s, formula 2, substituting the values, has the form
Q=(4650+4,6-Gb)/((0,5+ Gb>0,23) According to these formulas, we build a static characteristic Q=f(GB)
Calculations are summarized in tables in the range 0< Gb<7.5
Table 1.
Gb 0 1 2 3 4 5 6 7,5
624,6-Gb 0 624,6 1249,2 1873,8 2498,4 3123 3747,6 4684,5
(Gt+Gb>0,23 0,115 0,345 0,575 0,805 1,035 1,265 1,495 1,84
Q 0 1810,4 2172,5 2327,7 2413,91 2468,77 2506,7 2545,9
for Gb>7.5 kg
Table 2.
Gb 8 9 10 12 13 14 15
4650+4,6-Gb 4686,8 4691,4 4696 4705,2 4709,8 4714,4 4719
(Gt+Gb>0,23 1,955 2,185 2,415 2,875 3,105 3,335 3,565
Q 2397,34 2147,094 1944,51 1636,59 1516,84 1413,613 1323,7
If now in the future to change the amount of supplied fuel, then the amount of supplied air will also change and we will determine the dependence Q=f(GB) according to formula (2).
Based on the data obtained, we construct a static characteristic dependence Q=f(GB) (Fig. 1), from which it can be seen that in order to obtain optimal fuel combustion at various amounts of fuel, it is also necessary to change the amount of air supplied.
The dependence of the fan air supply on its speed has the form Q1/Q2=n1/n2 shown in (Fig. 2), therefore, to regulate the air supply, it is necessary to adjust the fan speed, since Q=GB, then we can conclude that by changing the engine speed, you can change the amount of air supplied air while the required speed control range will be determined by the ratio:
D =Gb max /GBmin
Fig 1. DependencyQ=f(GB) Fig 2. Dependence of the supplied air quantity
on the fan speed
Conclusions: It can be seen from the analysis that in order to increase the energy performance of the fuel combustion chambers and obtain the maximum temperature, it is necessary, in addition to regulating the fuel, to supply a certain amount of air, at which the process of complete combustion of the fuel and the release of the maximum temperature will occur. An investigator with a change in the supply of fuel to the combustion chamber must also change the amount of air supplied that is called to operate at the maximum characteristic point thereby obtaining maximum efficiency.
REFERENCES:
Bystritsky, G.F. Fundamentals of Energy: textbook / G.F. Bystritsky. M.: INFRA-M, 2006. 278 p
Lebedev, V.I. Calculation and design of heat generating installations of heat supply systems: textbook. allowance for universities. M.: Stroyizdat,1992. 360 р; Handbook on automated electric drive, edited by V.A. Alekseev, A.V. Shinyansky. M. : Energoatomizdat, 1986.
Olimjon Toirov, Kamoliddin Alimkhodjaev, Akhror Pardaboev Analysis and ways of reducing electricity losses in the electric power systems of industrial enterprises, SUSE-2021, E3S Web of Conferences 288, 01085 (2021) https://doi.org/10.1051/e3sconf/202128801085
Olimjon Toirov, Utkir Mirkhonov Principles for Controlling the Excitation of Synchronous Motors of the Compressor Installation, International Journal of Advanced Research in Science Engineering and Technology, Vol. 7, Issue 5 , P. 13876-13881, 2020.
Olimjon Toirov, Utkir Mirkhonov Overview of Compressor Installations and Issues of Their Energy saving, International Journal of Advanced Research in Science Engineering and Technology, Vol. 6, Issue 10, P. 11446-11452, October 2019. Арипов Н.М., Тоиров О.З., Усмонов Ш Ю., Кучкарова Д.Т. Основные технические требования по диапазону и точности регулирования скорости перемотки шелка-сырца с применением интелектуального электропривода // Вестник Казанского государственного энергетического университета, 2021. № 1 (49). С. 218-225.
Kamalov Tolyagan, Toirov Olimjon, Ergashev Shahboz Modern condition and possibilities of program management of frequency-adjustable electric drives // European research. 2016. №6 (17). URL: https://cyberleninka.m/article/n/modern-condition-and-possibilities-of-program-management-of-frequency-adjustable-electric-drives (дата обращения: 16.05.2022).
