Heat Carrier Research Articles

Time-Delayed Anticancer Effect of an Extremely Low Frequency Alternating Magnetic Field and Multimodal Protein-Tannin-Mitoxantrone Carriers with Brillouin Microspectroscopy Visualization In Vitro.

The effect of an extremely low frequency alternating magnetic field (ELF AMF) at frequencies of 17, 48, and 95 Hz at 100 mT on free and internalized 4T1 breast cancer cell submicron magnetic mineral carriers with an anticancer drug, mitoxantrone, was shown. The alternating magnetic field (100 mT; 17, 48, 95 Hz; time of treatment-10.5 min with a 30 s delay) does not lead to the significant destruction of carrier shells and release of mitoxantrone or bovine serum albumin from them according to the data of spectrophotometry, or the heating of carriers in the process of exposure to magnetic fields. The most optimal set of factors that would lead to the suppression of proliferation and survival of cells with anticancer drug carriers on the third day (in comparison with the control and first day) is exposure to an alternating magnetic field of 100 mT in a pulsed mode with a frequency of 95 Hz. The presence of magnetic nanocarriers in cell lines was carried out by a direct label-free method, space-resolved Brillouin light scattering (BLS) spectrometry, which was realized for the first time. The analysis of the series of integrated BLS spectra showed an increase in the magnetic phase in cells with a growth in the number of particles per cell (from 10 to 100) after their internalization. The safety of magnetic carriers in the release of their constituent ions has been evaluated using atomic absorption spectrometry.

The effect of doping on the electrons and holes in quantum dot semiconductor optical amplifiers

Abstract The doping effect on the reservoir carrier temperature of the electron and hole in quantum dot optical amplifiers (QD SOAs) has been formalized and modeling, taking into account the most of carrier heating (CH) contributions such as; free carrier absorption, carrier heating time relaxation, interdot relaxation time, occupation probability of dot level, injected current and electron-hole interaction. The theoretical simulation shows the carrier temperature increasing straight forward with increasing the surface density of the donor and accepter which had not studied earlier as the best of our knowledge. It clears that, the surface carrier concentration of donor or acceptor atoms supplying more hot carriers for wetting layer (WL) which is leading an increasing the carrier temperature. In other word, the long life time of carriers from WL to Quantum Dot (QD) states is very high. Consequently, the collision of carriers and nonradiative relaxation are increasing the CH effect. Also, the majority of carrier is responsible on the increasing of electron or hole temperature, so the variation electron temperature in N-type is higher than hole in valence band, while the reverse is done with doping with P-type.

Self-focusing/defocusing of skew-cosh-Gaussian laser beam for collisional plasma

The inverse relationship between the linear increase in skewness parameter s and the domain’s width of the order of skewness n plays a vital role in both critical beam radius and propagation dynamics of skew-cosh-Gaussian (skew-chG) laser beams. The interplay between the skewness parameter s and the order of skewness n is explored analytically and graphically in the current study to unveil the complexity of the propagation dynamics of the skew-chG laser beam. Naturally, the intensity’s complexity considerably affects the dielectric constant of the medium. Basically, the nonlinearity in the dielectric function of collisional plasma is attributed to the non-uniform heating of energy carriers along the wavefront of the laser beam, which becomes important and is used in the current study. By following Akhmanov’s parabolic wave equation approach under Wentzel–Kramers–Brillouin and paraxial approximations, the nonlinear differential equations are set up for the beam width parameters f 1 and f 2 and solved numerically. The present work analytically investigates the domains of the order n of skew-chG laser beams for a given set of skewness parameter s to investigate their effects on the self-focusing and defocusing of skew-chG laser beams. The critical curve also gets affected significantly due to the choice of domains for n. Finally, the numerical results are presented in the form of graphs and discussed in this study.

Автоматизация расчета реактора для синтеза серосодержащего сорбента, предназначенного для извлечения из сточных вод ионов тяжелых металлов

An automated algorithm for calculating the time of the full cycle of operation, the stages of thermal stabilization and cooling of the reaction mixture in a reactor designed for the synthesis of a sulfur-containing sorbent produced on the basis of waste products from metallurgy, petrochemistry (sulfur), epichlorohydrin (1, 2, 4-trichloropropane) and the pulp and paper industry (lignin) for extraction from wastewater of heavy metal ions. The use of algorithms and a program for automated calculation of the reactor helps to reduce the complexity of production costs and the cost of the finished sorbent, increases the reliability of calculations and the quality of design solutions. The developed algorithms and program include the following calculation routines: physico-chemical properties of the components of the reaction mixture and the choice of a mixing device (propeller three-bladed agitator), taking into account the viscosity of the mixture; hydrodynamic calculation of the mixing device and heat transfer when heating the mixture from 20 to 45 °C; heat transfer during thermal stabilization and cooling of the working mixture, as well as the time of the full cycle of the reactor. The proposed algorithm of heat transfer during thermal stabilization of the reaction mass is based on the determination of the temperature range of water heating, compensating for heat losses. For this purpose, the inverse problem of heat transfer with unknown temperatures over a hot heat carrier is formulated and solved, such that the average value between them is a thermostabilizable value. An algorithm for calculating the cooling process of the reaction mixture in a sulfur-containing sorbent synthesis reactor, taking into account heat losses to the environment in the amount of 5%, is presented. A program has been developed that implements the presented algorithms in C#, designed to automate the calculation of a sulfur-containing sorbent synthesis reactor designed to extract heavy metal ions from wastewater.

Heat recovery with low pressure loss for natural ventilation

Regenerative heat exchangers are widely used in life support systems, gas turbines, boilers and other high-temperature industrial installations. These heat exchangers are used for cooling and heating gases, humidification and dehumidification of gases, heat recovery from high-potential heat carriers. Today, the increase in energy consumption and the increase in energy prices require a large-scale energy-saving policy in the creation of modern engineering structures – residential, commercial and industrial facilities alike. When designing and creating life support systems to save energy, it is advisable to use secondary energy resources, such as, for example, the heat of the air removed from the room. The energy intensity of conventional ventilation systems is on average 50–80% of the total energy intensity of the engineering systems of the facility where they are operated. The use of rotating regenerative heat exchangers in ventilation and air conditioning systems makes it possible to return up to 85% of heat to the system at a relatively low capital investment. In this regard, when improving such systems, considerable attention should be paid to the calculation, optimization and increase in the efficiency of heat exchangers. Thus, this work is about increasing the efficiency of rotating regenerative heat exchangers in ventilation and air conditioning systems.

Coherent Terahertz Detection via Ultrafast Dynamics of Hot Dirac Fermions in Graphene.

Graphene has recently been shown to exhibit ultrafast conductivity modulation due to periodic carrier heating by either terahertz (THz) waves, leading to self-induced harmonic generation, or the intensity beat note of two-color optical radiation. We exploit the latter to realize an optoelectronic photomixer for coherent, continuous-wave THz detection, based on a photoconductive antenna with multilayer CVD-grown graphene in the gap. While for biased THz emitters the dark current would pose a serious detriment for performance, we show that this is not the case for bias-free THz detection and demonstrate detection up to frequencies of at least 700 GHz at room temperature, even without optimized tuning of the doping. We account for the photocurrent and photomixing response using detailed simulations of the time-dependent carrier distribution, which also indicate significant potential for enhancement of the sensitivity, to become competitive with well-established semiconductor photomixers.

Investigating the microwave properties of carbon materials from microwave-driven methane pyrolysis

Rising carbon dioxide emissions due to fossil fuel combustion has led to the urgent need to investigate and adopt different energy solutions that can mitigate this problem. Hydrogen has surfaced as a promising alternative in the pursuit for CO2-neutral energy systems. Microwave pyrolysis of methane has recently emerged as an innovative method to accomplish this goal. To enhance our understanding of this technique and its scalability, it is essential to explore the microwave characteristics of the carbon used and generated during this process. This work investigates the microwave properties of two carbon samples (seed carbon; SC and product carbon; PC) from microwave-driven pyrolysis of methane. The cavity perturbation technique was employed from room temperature to 1250 °C for frequencies of 397, 912, 1429, 1948 and 2467 MHz. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis were also performed to elucidate the permittivity results. It was found that SC initially showed a decline in permittivity values up to 200 °C which is attributed to the release of moisture from the sample. These results were correlated to TGA/DSC which showed 5 % mass loss from 100 to 155 °C. The permittivity gradually reached a peak after which it started to fall due to high conductivity. In the case of the PC, the permittivities exhibited undulations but the values remained consistent. Since this form of carbon is formed at elevated temperature, no loss in moisture was seen in TGA/DSC. These findings indicate that the microwaves can penetrate and heat both the samples uniformly across their entire volume, resulting in efficient heating. SC demonstrated higher permittivity magnitudes compared to PC, suggesting its better responsiveness to microwave fields. Nonetheless, the possibility of thermal runaway in SC renders it less favorable for applications involving microwave-driven pyrolysis. XRD analysis showed that the samples SC and PC demonstrated amorphous carbon structures, with PC showing indications of graphitization to some extent. Both SC and PC have the potential to serve as microwave heat carriers in the methane pyrolysis process. This suggests that utilizing the carbon produced can enable a self-sufficient process, eliminating the necessity for costly catalysts.

Toward the ultimate efficiency of methane to syngas conversion by partial oxidation: A moving bed reactor with parallel preheating of reactants

The conversion of methane to syngas by partial oxidation combined with steam reforming in a counterflow moving bed reactor is theoretically considered. The conversion proceeds in filtration combustion mode with the non-premixed flows of steam–methane and oxidant gas. The flow of solid granular heat carrier is divided in two subflows used to preheat, respectively, steam–methane flow and oxidant gas flow prior to the reaction. The calculations are performed under assumption of thermodynamic equilibrium established in the reaction products. For the main control parameters – the flow rates of oxidant gas, steam, and solid heat carrier, related to the flow rate of methane – the parametric domain has been determined that provides a highly efficient conversion in the absence of soot in the products. Efficient heat recuperation with the solid heat carrier makes attainable conversion with the oxygen-to-methane molar ratio as low as 0.43. The flow arrangement with separate preheating of the reactants prior to reaction promises a highly efficient method of converting hydrocarbons to syngas or hydrogen.

Characteristics of β-Ga2O3 MOSFETs on polycrystalline diamond via electrothermal modeling

The integration of polycrystalline diamond (PCD) has been considered as a promising approach for overcoming the thermal management challenges in β-Gallium oxide (β-Ga2O3) metal-oxide-semiconductor field effect transistors (MOSFETs). This study investigates the coupled electrical and thermal characteristics of β-Ga2O3-on-diamond MOSFETs via electrothermal modeling. Results reveal that thicker diamond improves heat transfer efficiency with an optimal value of ∼100 μm by utilizing regions with higher thermal conductivity. The ambient temperature (Tamb) correlates negatively with the device temperature rise (ΔT) due to reduced electrical mobility and current density at elevated temperatures. Excellent electrical performance has been demonstrated for β-Ga2O3 MOSFETs, with a high saturation current density (Id,sat = 42.7 mA/mm) and a low specific on-resistance (RON,sp = 264.8 mΩ·mm2) at 300 K with Vg = −2 V and Vd = 20 V, along with a high on/off ratio (Ion/Ioff ∼ 1011) and a low subthreshold swing (SS = 83.3 mV/dec), making it highly suitable as a power switch. Comparative analysis with devices on other substrates (Si, SiC, and sapphire) highlights the exceptional carrier mobility and heat spreading capability benefited from the diamond substrate, especially at high power levels. Our TCAD-based fully-coupled electrothermal simulations provide comprehensive and accurate insights into the electrical and thermal performance of Ga2O3-based devices, offering guidance for the design and optimization of high-power devices.

Studying Flotation of Gold Microdispersions with Carrier Minerals and Pulp Aeration with a Steam–Air Mixture

This work is aimed at obtaining new knowledge in the field of interactions of polydisperse hydrophobic surfaces in order to increase the extraction of mineral microdispersions via flotation. The effect of high velocity and the probability of aggregating fine particles with large ones are used to increase the extraction of finely dispersed gold in this work. Large particles act as carrier minerals, which are intentionally introduced into a pulp. The novelty of this work lies in the fact that a rougher concentrate is used as the carrier mineral. For this purpose, it is isolated from three parallel pulp streams by mixing the rougher concentrate, isolated from the first stream of raw materials, with an initial feed of the second stream; accordingly, the rougher concentrate of the second stream is mixed with the initial feed of the third stream, and the finished rougher concentrate is obtained. In this mode of extracting the rougher concentrate, the content of the extracted metal increases from stream to stream, which contributes to the growth in its content in the end product. Moreover, in order to supplement forces involved in the separation of minerals with surface forces of structural origin in the third flotation stream, the pulp is aerated for a short time (about 15%–25% of the total) with air bubbles filled with a heat carrier, i.e., hot water vapor. Within this accepted flotation method, the influence that the surface currents occurring in the wetting film have on its thinning and breakthrough kinetics is proposed to be in the form of a correction to a length of a liquid slip in the hydrophobic gap. The value of the correction is expressed as a fraction of the limiting thickness of the wetting film, determined by the condition of its thickness invariability when the streams are equal in an interphase gap: outflowing (due to an action of the downforce) and inflowing (Marangoni flows and a thermo-osmotic stream). Gold flotation experiments are performed on samples of gold-bearing ore obtained from two deposits with conditions that simulate a continuous process. Technological advantages of this developed scheme and a flotation mode of gold microdispersions are shown in comparison with the basic technology. The purpose of this work is to conduct comparative tests on the basic and developed technologies using samples of gold-bearing ore obtained from the Natalka and Olimpiada deposits. Through the use of the developed technology, an increase in gold extraction of 7.99% and in concentrate quality (from 5.09 to 100.3 g/t) is achieved when the yield of the concentrate decreases from 1.86 to 1.30%, which reduces the costs associated with its expensive metallurgical processing.

Incorporation of CaZrO3 into calcium-based heat carriers for efficient solar thermochemical energy storage

Calcium-based materials (CaCO3/CaO) have shown significant potential for use in thermochemical energy storage systems for concentrated solar power generation due to their low-cost, high-energy storage efficiency, and operational temperature range. However, the energy storage performance of calcium-based heat carriers degrades rapidly over cycles due to high-temperature sintering, limiting practical applications. In this study, we incorporated Zr into CaO using both heat-drying and freeze-drying methods, forming CaZrO3 as a physical barrier to prevent agglomeration and sintering of calcium particles at elevated temperatures. Experimental results demonstrated that Zr incorporation markedly improved cyclic energy storage stability, particularly for heat carriers derived from freeze-drying. Cao incorporated with 10 % CaZrO3 (FD-Zr10) showed a high energy storage density of 2161.75 kJ/kg over ten storage/release cycles, which was 25.89 % higher than that of pure CaO sample. Even over an extended operation of 30 cycles, FD-Zr10 still possessed the high energy storage density of 1939.76 kJ/kg. CO2-containing harsh storage conditions caused more sintering for the heat carriers, thus resulting in the performance reduction, but FD-Zr10 performed much better than other samples in resisting sintering. Various characterization analyses were conducted to investigate the reasons for the samples' cyclic stability. It was discovered that freeze-drying incorporation generated a dendritic surface with a more abundant pore structure, and the incorporated CaZrO3 functioned as a metal skeleton to mitigate high-temperature sintering.

Initial stage of formation of vortex flow in an inductor with counter-rotating magnetic fields

In this article, unsteady flows of electrically conductive fluid in a cylindrical cavity under the action of differently directed rotating magnetic fields are investigated. The relevance of the study is due to the presence of such a flow in the flow meter for liquid-metal heat carrier which is currently under development. The subject of study is the process of formation of the spin-up flow stage in a combined inductor of a rotating magnetic field. The acceleration or the spin-up stage is characterized by a significant change in the angular velocity of the liquid and begins with the formation of low pressure areas due to centrifugal forces. The alternation and movement of low and high pressure areas lead to velocity pulsations. For small values of the control parameter, which is the Taylor number, the flow energy gradually increases. In this case, the steady flow consists of two azimuthal and several poloidal vortices with clearly defined structures. When the Taylor number exceeds a critical value, strong pulsations occur in the flow, resulting in the decay of large-scale vortices. The intensity of the current is characterized by the Reynolds number. A power-law relationship with an exponent of 1.57 has been established between the Reynolds and Taylor numbers. It has been found that the time of formation of a steady flow varies from several seconds to tens of seconds, depending on the value of the Taylor number. The estimates of the control parameters have been obtained for a flowmeter operating in a typical mode. It has been shown that for the correct measurement of flow velocity in the flowmeter, it is necessary that that the Taylor numbers be higher than 108. The study is carried out using mathematical modeling and the obtained results are verified by experiment. The average calculated profiles are located within the confidence intervals of the experimental profiles.

Determination of Pipe Diameter Using Optimization Method

During the design phase of engineering networks, a critical issue remains the selection of pipe diameters that minimize capital investments for transporting the heat carrier from the heat source to the consumers. Object of study: a pressurized pipeline of circular cross-section with a moving heat carrier. Subject of study: total monetary costs for transporting the heat carrier as a function of the chosen pipeline diameter. Objective of study: to determine the pipe diameter that achieves maximum cost savings for transporting the heat carrier under given design conditions. Research methods: theory of hydraulic calculation for circular cross-section pipelines and theory of heat transfer through a single-layer cylindrical wall under steady-state conditions. Research results: using an example from a centralized heating system pipeline section, it was established that for a mass flow rate of the heat carrier equal to 32.9 t/h, the optimal pipe size would be 76×3 mm (nominal diameter 70 mm). Under current tariffs for thermal energy (24.82 USD/Gcal) and electrical energy (6.65 USD/(MW⋅h)), the total monetary costs for transporting the heat carrier over a heating season would be 56.28 USD per 1 running meter of pipeline. In comparison, with a nominal diameter of 50 mm, the total costs amounted to 90.37 USD; with a diameter of 80 mm, the costs were 63.29 USD. The developed method for hydraulic design calculations is universal and can be applied in the design of engineering networks where the working medium is a moving heat carrier (steam or hot water).

Development of complex methods for exergetic losses calculating in heat transfer through wall in air-heater heat utilizers

Ensuring high economic indicators of power plants of various purposes, which include waste gas heat utilization systems, is possible with the use of effective heat utilization equipment. One of the criteria for evaluating the thermodynamic perfection of power plants is the amount of exergy losses in the structural elements of the plant. A decrease in exergy losses corresponds to an increase in exergy efficiency. Determination of the structural elements in the heat utilization system, in which the maximum exergy losses are localized, will allow to influence them in a targeted manner in order to increase the exergy efficiency of the installation. The paper presents the results of the development of complex methods for calculating local exergy losses in the processes of heat transfer through flat and cylindrical walls of air-heated heat exchangers, which are included in the heat utilization systems of power plants of various purposes. Complex methods are based on integral equations for calculating exergy losses, as well as differential equations of heat transfer theory when applied to heat utilization systems. The classification of exergy losses for heat utilization systems of power plants has been carried out, and the location and type of local exergy losses have been determined. Three types of local exergy losses are considered: losses during heat transfer from the heat carrier to the wall, heat transfer from the wall to the heat carrier, and exergy losses in heat conduction processes. A system of integrodifferential equations was developed and analytical expressions were obtained for the calculation of local exergy losses in heat transfer processes through the flat and cylindrical walls of air-heating heat exchangers. The introduction of new complex research methods expands the possibilities of using exergy analysis methods to increase the exergy efficiency of heat utilization systems. Research using the specified methods will allow to develop heat utilization systems with high indicators of energy and exergetic efficiency.

THREE-DIMENSIONAL MATHEMATICAL MODEL OF THE INDUCTION-TYPE HEAT GENERATOR. VOLTAGE MODE

Induction type heat generators are widely used in technologies for drying materials of natural and artificial origin. This allows using non-contact action on the heat carrier, unlike traditional heat generators, where air heated by the products of combustion of mineral fuel acts as a drying agent, to exclude the impact of carcinogens on the final product, to ensure fire safety in the absence of an open flame, does not pollute the environment with combustion products in due to their absence. Despite the fairly wide industrial implementation of these technologies, the issue of creating new and improving known induction heating systems for drying technologies of natural and artificial origin remains relevant, and their design methods require further development and generalization. The purpose of this work is to develop, using the method of secondary sources, a mathematical model for the analysis of the three-dimensional magnetic field in a three-phase heat generator of the induction type, taking into account the symmetry of its geometry, powered by a three-phase voltage source. On the basis of the method of secondary sources, a three-dimensional mathematical model of an induction-type heat generator was developed when it is powered by a three-phase voltage source with a load in the form of unbonded ferromagnetic conductive tubes/rods, taking into account the symmetry of the density distribution of secondary sources of the electromagnetic field, which allows rational use of computing resources, conducting analysis influence of the geometrical, electrophysical, mode parameters of the induction type heat generator on heat losses in the loaded, which are heat sources for heating the coolant.

Non-destructive Thermal Monitoring of Temperature and Flow Rate of the Heat Carrier in a Heating Device

Conducting various calculations for the heating system of a building under operational conditions is impossible without knowledge of the temperature and flow rate of the heat carrier at specific points. Contact measurement means are not always applicable, especially for small-diameter pipelines. Measurement techniques based on the theory of non-destructive thermal inspection allow for remote and timely acquisition of all necessary information. The object of the study is the floor node of the building's heating system. The subject of the study is the temperature and flow rate of the heat carrier passing through the heating device. The research aim is to determine the temperature and flow rate of the heat carrier passing through the heating device under operational conditions. The research method involves the theory of non-destructive thermal inspection, as well as heat balance and heat transfer equations for a vertical flat wall. Research findings reveal that during thermovisual inspection, the temperature of the heat carrier in the supply and return pipelines of the floor node respectively amounted to 51.6 ℃ and 49.6 ℃. The flow rate of the heat carrier through the heating device model MS-140M2-500, with a heat transfer coefficient of 8.5 W/(m²⋅K), was determined to be 195.0 kg/h. Recommendations include utilizing a thermal imager with an absolute measurement error not exceeding ±0.15 ℃ for determining the flow rate of the heat carrier through the heating device. The influence of measurement error of indoor air temperature on the accuracy of determining the heat carrier flow rate is insignificant (not exceeding ±2%). The relative error in determining the heat transfer coefficient of the heating device does not exceed ±1%.

Heat pump technology for utilizing the heat of secondary energy resources in the catalytic method of obtaining biodiesel

Heat pump technology for utilisation of heat of secondary energy resources in catalytic method of production of biodiesel fuel is implemented. Algorithm for control of technological parameters at all stages of production of biodiesel fuel is proposed and analysis of parameters of its quality is performed. Heat pump system is represented in the form of two recirculation circuits of low-potential and high-potential heat carriers, preparation of which was carried out in stages of low and high pressure of heat pump. Exergetic analysis was performed, functional dependencies of exergy flows coming out of the considered types of process equipment were obtained. The obtained hybesel fuel complied with the requirements of GOST 23513-79. The proposed heat pump technology reduced specific energy consumption by 13-14%; improve environmental safety at all stages of the process; maximum reduction of spent heat carriers emission into the ambient atmosphere.

Heat transfer and irrigating liquid hydrodynamics on one-row vertical bundle of inclined tubes in falling film heat exchanger

Spiral-wound heat exchangers widely used currently in various industries provide efficient heat transfer between media through spiral tube winds at evaporation and boiling of falling liquid film. The investigated bundle in the form of one-row vertical bundle of inclined tubes (5 degrees to the horizon) simulates a part of a spiral-wound heat exchanger. Heat transfer and hydrodynamics processes are studied at falling film irrigation by liquid R21 refrigerant at 3 bar of absolute pressure with water as heat carrier. The bundle is placed inside of rectangular heat exchanger with optical windows. Heat transfer measurements are performed for tubes at different positions on the bundle height. Irrigation densities corresponded to falling film Reynolds numbers 300 – 1100, heat flux values within the range of 5000 – 10000 W/m2.

Preventing scale formation on heat transfer surfaces

The article considers the problem of scaling in power equipment on the example of Thermal Power Plants in the Republic of Kazakhstan. The most optimal solution is proposed – replacement of the traditional preparation of the feed water in the heat network by an ion exchange method for a more effective method using complex-forming reagents. The influence of inhibitor of mineral salts concentration (IMSC), trisodium phosphate, and Zinc Complex 1-hydroxyethylendiphosphonic acid (Zn-OEDF), as well as the heat carrier temperature on scaling intensity, has been studied to prevent the equipment from scale formation and corrosion. The technological parameters of feed water in the presence and absence of complex formers have been determined. The corrosion resistance of steel No. 3 samples in the presence of said reagents has been studied. The most optimal complexone has been chosen to prepare feed water for the TPP heating network.

К РЕШЕНИЮ ЗАДАЧИ КОЛИЧЕСТВЕННОГО РЕГУЛИРОВАНИЯ В СИСТЕМАХ ТЕПЛОСНАБЖЕНИЯ

The quantitative regulation of the heat supply process has a number of significant advantages and is widely used abroad. This method of regulation is also used in the Russian Federation. At the same time, the algorithmization of quantitative regulation is currently still quite problematic and requires further development. For example, the literature data on the algorithm proposed by E.Ya. Sokolov are characterized by the “omission” of the procedures of inference and justification, which is particularly undesirable for educational applications. In addition, the algorithm does not work across the entire range of thermal loads (outside temperatures). Purpose of the study. To develop an algorithm for quantitative regulation in terms of its subsequent use as part of the algorithmic support of an automated control system (ACS) for heat supply. Materials and methods. Literature data on the issue under consideration was analyzed. Using models of heating systems and heat losses of buildings, we compiled a balance equation that makes it possible to find the necessary coolant flow for heating. Results. A detailed substantiation and derivation of the algorithm for quantitative regulation of heat supply according to the heating load is proposed, and its characteristics were analyzed. The conditions for the physical feasibility of heating are taken into account. The algorithm as a whole is represented by a two-interval formula; in the second range of outdoor temperatures, the heat carrier flow rate is calculated based on the condition that the return water temperature should be noticeably higher than the indoor air temperature of the heated premises. However, when regulating the heat carrier flow in the second interval, an overestimated power of the heating system will be observed, i. e. some overshoot is possible. It is shown that with an increase in the minimum allowable value of the return water temperature, the range of outdoor temperatures in which regulation is possible in the first interval (ideal regulation without overflow) noticeably narrows, and when the water temperature in the supply line decreases, conversely, it expands. Conclusion. The results of the work can be used to develop algorithmic support for automated control systems for heat supply.