Екатерина Вавилова – All sciences. №1, 2023. International Scientific Journal (страница 5)

Nikola Tesla died in his New Yorker Hotel room on the night of January 7-8, 1943, at the 87th year of his life. The body was discovered on January 8 by the maid Alice Monahan, who entered the room despite the "do not disturb" sign posted by Tesla on January 5. According to the coroner's report, death occurred around 22:30 at night, presumably from coronary thrombosis. On January 12, the body was cremated, and the urn with the ashes was installed at Ferncliffe Cemetery in New York. In 1957, it was moved to the Nikola Tesla Museum in Belgrade.

PHYSICAL AND MATHEMATICAL SCIENCES

CO₂ GAS CONCENTRATION MONITORING DEVICE

UDC 620.191

Qo’ldashov Obbozjon Xakimovich

Doctor of Technical Sciences, Professor of the Scientific Research Institute "Physics of Semiconductors and Microelectronics" at the National University of Uzbekistan

Bekchanov Ulug’bek Qo’ziboy o’g’li

2nd year Master of the Department of "Physics of Semiconductors and Polymers" of the Faculty of Physics of the Mirzo Ulugbek National University of Uzbekistan

Scientific Research Institute «Physics of Semiconductors and Microelectronics» at the National University of Uzbekistan

Annotation. The article discusses the principles of constructing an optoelectronic device for monitoring the concentration of CO2 gases. Intense absorption lines of CO2 gases have been determined. The optoelectronic device uses LEDs based on GaAlAsSb/GaInAsSb/GaAlAsSb (3.12 microns) as the emitting diode at the reference wavelength, and LEDs based on GaAlAsSb/GaInAsSb/GaAlAsSb (3.39 microns) as the emitting diode at the measuring wavelength.

Keywords: gas analyzer, carbon dioxide, control, flowchart, time diagrams.

Аннотация. В статье рассматриваются принципы построения оптоэлектронного устройства для контроля концентрации CO2 газов. Определены интенсивные линии поглощения CO₂ газов. В оптоэлектронном устройстве использованы в качестве излучающего диода на опорной длине волне светодиоды на основе GaAlAsSb/GaInAsSb/ GaAlAsSb (3.12 мкм), а излучающего диода на измерительной длине волны светодиоды на основе GaAlAsSb/GaInAsSb/GaAlAsSb (3.39 мкм).

Ключевые слова: газоанализатор, углекислые газы, контроль, блок схема, временные диаграммы.

In recent years, more and more attention has been attracted to the problems of using clean unconventional renewable energy sources (NVE) for the needs of energy supply to various agricultural and industrial facilities. The relevance and prospects of this energy sector are due to two main factors: the catastrophically difficult situation of the environment and the need to search for new types of energy.

The successes achieved in the creation of wind, solar and a number of other types of unconventional power plants are widely covered in various works, recently much attention has been paid to geothermal energy. The prospects for using the Earth's heat energy are truly limitless, because under the surface of our planet, which is a giant natural energy boiler, huge reserves of heat and energy are concentrated.

Today, geothermal energy is actively developing in Uzbekistan. On the territory of Uzbekistan, forecast geothermal resources at accessible depths (up to 5-6 km) are 4-6 times higher than hydrocarbon resources. The main consumers of geothermal resources in the near and long term in Uzbekistan will undoubtedly be heat supply and, to a much lesser extent, electricity generation.

By absolute value, of all types of renewable energy, the subsoil of Uzbekistan has the greatest integral energy potential in the form of heat from dry rocks (petrothermal resources) and large basins with hydrothermal waters.

Geothermal waters are available in all regions of Uzbekistan. Long-term surveys have allowed to identify 8 large basins with hydrothermal resources on its territory. The gross potential of geothermal waters is estimated at 171 thousand tons. However, the technical potential of geothermal sources has not yet been determined. The Fergana Valley and Bukhara Viloyat have the greatest potential of geothermal waters. The average temperature of geothermal waters in the republic is 45.5 °C, the warmest waters are in Bukhara (56 °C) and Syrdarya (50 °C) viloyats. It should be noted that the practical realization of the energy of geothermal waters is associated with the development of appropriate environmental measures due to their chemical composition. Petrothermal energy resources in the form of dry rocks with temperatures from 45 to 300 °C have also been identified in the country. The realization of the potential of petrothermal energy (heat of dry rocks, granitoids) can be carried out using power plants on low-boiling working bodies with a block capacity of 40 MW on the basis of the Chust-Adrasman petrothermal anomaly in the Fergana Valley [1].

The main advantage of geothermal energy is its practical inexhaustibility and complete independence from environmental conditions, time of day and year [2-3]. Geothermal energy owes its "design" to the red-hot central core of the Earth, with a huge supply of thermal energy. Only in the upper three-kilometer layer of the Earth is stored the amount of thermal energy equivalent to the energy of about 300 billion tons of coal [4].

Figure 1 shows a diagram of the use of geothermal resources.

Fig.1. Diagram of the use of geothermal resources

Geothermal energy is widely and successfully used in various sectors of the national economy. There are very broad prospects for expanding the scope of its application:

– heat supply (heating and hot water supply) of civil and industrial buildings and structures;

– heat supply of agricultural facilities (greenhouses and greenhouses of both year—round and seasonal duration, fish-breeding ponds, poultry farms, etc.);

– satisfaction of technological processes of industrial enterprises in heat (drying of wood for furniture production, fermentation of tea leaves, etc.);

– satisfaction of the communal needs of the population (baths, swimming pools, laundries, etc.);

– balneological purposes; electricity generation.

Geothermal resources have several components: they can be considered simultaneously as a source of electrical and thermal energy and as a source of valuable chemical compounds: amorphous silica, B, Li, Zn, Mn, HS, NaCl, geothermal gases H2S, CO2.

Data on the chemical composition of geothermal resources show the presence of geothermal gases (H2S, CO2) in them [4], the control of the concentration of which greatly facilitates their development and the search for new sources of mineral raw materials.

As is known, there are intense absorption lines of geothermal CO2 gases in the range of 1.7—4.8 microns. The development of optoelectronics and its element base, the creation of new highly efficient semiconductor radiation sources create prerequisites for the development of highly sensitive and accurate, reliable devices for monitoring the concentration of geothermal gases (H2S, CO2).

In this paper, a device for monitoring the concentration of geothermal gases is proposed.

The block diagram of an optoelectronic device for monitoring the concentration of geothermal gases is shown in Fig.1, and its time diagrams are shown in Fig.2.

The device for monitoring geothermal gases contains a power source 1, a rectangular pulse generator with two antiphase outputs 2, to one output of which a frequency divider 3 (serial counter) is connected, the output of which is connected via a single-vibrator 4 to the control input of the exponent modulator 5, an emitter repeater 6, two electronic keys 7 and 8, emitting diodes working 9 and the reference 10, emitting at the reference and working wavelengths, respectively, a gas chamber 11, a photodetector 12 connected to the first differentiating device 13, the output of which is through the threshold input of the coincidence circuit 15, the first input of which is connected to the output of the second differentiating device 16, the input of which is connected to the emitting diode 10, the counter 17, the counting input of which is connected to the output of the coincidence circuit 15, and its input "zero setting" is connected to the output of the single-vibrator 4.

The gas chamber 11 is irradiated with two radiation streams F0l1 and F0l2 at the reference l1 and working l2 wavelengths, respectively. The radiation fluxes that have passed through the gas chamber will be equal, respectively:

(1)

where: F0l1 and F0l1 are radiation fluxes feeding to the gas chamber at wavelengths l1 and l1, respectively, Fl1, Fl2 are radiation fluxes after passing through after passing through the gas chamber at wavelengths l1 and l2, respectively,

N1 – concentration of a mixture of gaseous substances,

L is the length of the optical path, i.e. the length of the gas chamber,

N2 is the concentration of the gaseous substance to be determined,

K1 is the scattering coefficient of a mixture of gaseous substances,

K2 is the absorption coefficient of the determined gaseous substances.

The flow of F0l1 changes in time (t) according to the exponential law

(2)