Infrared Heating System Research Articles

Application of artificial intelligence to predict energy consumption and thermal efficiency of hybrid convection-radiation dryer for garlic slices

This study aims to examine the energy-related aspects of a hybrid convection-radiation drying technique employed in the drying process of garlic slices. Several factors, including infrared radiation intensity (1500, 2000, and 3000 W/m2), air temperature (40, 50, and 60 °C), and airflow rates of the drying chamber (0.7, 1.0, and 1.5 m/s) were evaluated to optimize the responses of drying time (min), energy consumption (kJ), thermal efficiency (%), and specific energy consumption (MJ/kg). Furthermore, an Artificial Neural Network model was employed to predict the effects of the parameters above on the drying system's specific energy consumption, energy consumption, drying time, and thermal efficiency. The obtained data were analyzed using a self-organizing map and principal component analysis. Interestingly, the findings showed that increasing the air temperature and infrared radiation intensity led to shorter drying times, while higher airflow rates resulted in longer drying durations. Additionally, it was found that higher infrared intensity and air temperature, combined with lower airflow rates, improved the energy indices. Increasing the air velocity to 1.0 and 1.5 m/s at the same air temperature and radiation intensity resulted in a considerable increase in drying time by 9 and 22.7%, respectively. The lowest efficiency value of 10.1% was observed at 40 °C temperature and an air velocity of 1.5 m/s. The Artificial Neural Network model demonstrated high accuracy with a Root Mean Square Error of 0.05 and an overall accuracy of (95%) in predicting the drying parameters. Notably, the self-organizing map visualization revealed that higher air temperatures and radiation corresponded to lower drying times, energy consumption, and specific energy consumption. Conversely, higher airflow rates resulted in increased drying time and energy consumption. The present study suggested that 60 °C, 3000 W/m2 and 0.7 m/s are optimum conditions for efficiently drying garlic slices under the hybrid dryer. This investigation addresses the limitations and deficiencies of previous work on energy optimization and efficiency analysis of garlic under a hybrid dryer with infrared heating systems. Further studies on the economic feasibility of applying such a system for sample drying and the impact of drying on the thermal behaviors of the products need additional investigation.

Experimental performance analysis of an infrared heating system for continuous applications of drying

One feasible approach for enhancing material quality and expediting the dehydrating procedure is using infrared radiation to provide heat. The impact of infrared power (0.130–0.341 W/cm2), airflow (0.5–1.5 m/s), and slice thickness (2–6 mm) on mass transfer, drying kinetics, colour, shrinkage, and rehydration ratio conditions. During the process, the dried samples' initial moisture content of 86.7 % was decreased to 11 % (w.b.). Eleven statistical factors were used to compare eleven alternative mathematical models. The results of regression analysis indicated that the Midilli et al. model best describes the drying behaviour in both techniques. The outcomes exhibited that the drying period rose at airflow and thickness but decreased with intensity. While the shrinkage ratio increased and declined with air velocity, the rehydration ratio grew and dropped with increasing infrared radiation intensity and airflow. As the intensity and airflow increased, there was a noticeable increase in the overall colour difference between slices of fresh and dry apples. The outcomes of this investigation will offer a further understanding of the ideal drying settings to create apple slices for snacking or other culinary purposes.

RESEARCH OF STRUCTURAL AND MECHANICAL PROPERTIES OF MEAT AS AN OBJECT OF PROCESSING IN MEAT COMMINUTOR

This work is dedicated to the study of the energy efficiency of using electric heating systems in the classrooms of Ivano-Frankivsk National Technical University of Oil and Gas (IFNTUOG), where the actual state of heating systems and their efficiency in educational building №9 were determined. An experimental study was conducted, which included determining the heating and cooling time of working surfaces and the distribution of temperatures across them in a classroom; determining the distribution of thermal energy at several levels of the room. Experimental data were obtained to evaluate the effectiveness of different electric heating systems in classrooms in standby mode, which allowed selecting the infrared heating system based on ceiling heaters as the most optimal technical solution for providing an acceptable level of comfort and energy efficiency. The effectiveness of using air thermostats for the electric heating system based on infrared heaters, which operates in standby mode, leading to excessive electricity consumption, was also studied. The results confirm that the heating system using infrared panels ensures even heat distribution, maintains comfortable temperature and humidity conditions, and is distinguished by high energy efficiency. In contrast, the use of electric convectors with an inefficient water heating system does not provide adequate air heating, especially in spacious and high rooms, where heat dissipates quickly due to insufficient insulation. The data obtained during the scientific research, along with previous studies, allow for the development of an automatic intelligent heating and ventilation control system that will use the most advanced research results in the field of efficient operation of engineering systems in educational institutions.

Transcriptome profiling of two rice varieties reveals their molecular responses under high night-time temperature.

High night-time temperatures (HNT) pose a threat to the sustainability of crop production, including rice. HNT can affect crop productivity and quality by influencing plant physiology, morphology, and phenology. The ethylene perception inhibitor, 1-methylcyclopropene (1-MCP), can minimize HNT-induced damage to plant membranes, thereby preventing decrease in rice yield. In this study, we employed a transcriptome approach to investigate the effects of HNT, 1-MCP, and their interaction on two Texas rice varieties, Antonio and Colorado. The plants were exposed to temperatures of 25°C (ambient night-time temperature, ANT) and 30°C (HNT) using an infrared heating system from the booting stage until harvest, while 1-MCP was applied at the booting stage of rice development. Several physiological and agronomical traits were evaluated under each condition to assess plant responses. Leaf tissues were collected from the plants grown in the ANT and HNT conditions after the heat stress and 1-MCP treatments. Based on agronomic performance, Colorado was less negatively affected than Antonio under HNT, showing a slight reduction in spikelet fertility and leaf photosynthetic rate but no significant reduction in yield. The application of 1-MCP significantly mitigated the adverse effects of HNT in Antonio. However, no significant differences were observed in yield and leaf photosynthetic rate in Colorado. Furthermore, transcriptomic data revealed distinct responsive mechanisms in Antonio and Colorado in response to both HNT and 1-MCP. Several ethylene and senescence-related transcription factors (TFs) were identified only in Antonio, suggesting that 1-MCP affected the ethylene signaling pathway in Antonio but not in Colorado. These findings contribute to our understanding of the physiological differences between varieties exhibiting susceptible and tolerant responses to high night-time temperatures, as well as their response to 1-MCP and ethylene regulation under 1-MCP.

Development of a rapid heat cycle injection molding system using infrared radiation and convection heating and influence on morphology and mechanical properties

Conventional injection molding is widely used to produce plastic parts, mainly in the automotive industry, due to the high production ratios and quality of injection parts. Low mold temperatures are usually employed to decrease cycle molding time and final process costs; however, resulting surface defects include weld lines, sink marks, and warpage. Therefore, plastic parts are often subjected to secondary processes to reduce the surface defects. A dynamic mold heating and cooling control technology, rapid heat cycle molding (RHCM), was employed to optimize the injection molding process. The present study combined convection heating (pressurized water flow) and external infrared heating systems to investigate the effect of dynamic temperature control on the injection molding process. The infrared heating system was custom built to allow studying under controlled conditions the influence of several process parameters on the resulting morphology and mechanical properties. Results show significant gains from using the RHCM technology to optimize the conventional process, namely, at 100 °C no frozen layer is formed while simultaneously increasing the Young’s modulus. Industrial companies struggling with defects resulting from the thermal changes during injection molding can thus consider RHCM as a mitigation strategy and use these results as a guide for tool design and implementation of the technique.

Development and evaluation of an energy-efficient intelligent infrared heating system for industrial buildings

Energy efficiency is a global problem that has become a top priority for all developed countries in recent years. Limited energy resources and high pollution worldwide have led to an increase in research and development in terms of energy efficiency. In the present work, one of the energy-efficient methods for heating by using infrared sources is focused. The advantages of infrared heaters compared to standard heating sources are underlined. A comparative study of the energy consumed during heating by the most frequently used by the heating systems has been made, and the results of the theoretically calculated power costs are presented. An intelligent system has been developed for the management of the infrared heaters to reduce the consumption of electricity better. The intelligent control system is based on a fuzzy-logic control and an internet of things. Results of simulation experiments of the intelligent system are presented as well as of the application of the system in a real environment. During the experiments, the system successes to control the heaters and to reduce power consumption. The achieved results prove that signal processing and control can improve the performance by using modern sensor systems, thereby additional efficiency can be achieved by using the infrared heating. It is possible to develop different optimization systems and algorithms for increasing the energy efficiency of different heating systems.

РЕЖИМНЫЕ ПАРАМЕТРЫ ИНФРАКРАСНЫХ ЭЛЕКТРОНАГРЕВАТЕЛЕЙ НА ОСНОВЕ НАНОМОДИФИЦИРОВАННЫХ ЭЛАСТОМЕРОВ ДЛЯ ТЕХНОЛОГИЧЕСКИХ ПРОЦЕССОВ В АПК

Modernization of the agro-industrial complex can be based on the use of energy efficient technical approaches. One of the directions in the field of energy saving is the use of infrared (IR) heaters, for the creation of which it is most rational to use technological methods for obtaining composite materials based on dielectric matrices (elastomers) with the addition of conductive structures with nanosized geometric parameters (MСNTs - multilayer carbon nanotubes). Studies have shown that when the heater samples are turned on, a short-term current jump occurs, which is associated with heating of the elastomer with MСNT and the formation of an electric field in the composite structure. The inrush current ratio for sample No. 1 (Silagerm 8020, MCNT 3%, nickel 10%) is 3.56 A (setting time of the operating mode is 350 s), which is the highest value. The smallest inrush current ratio of 1.65 A (setting time of the operating mode 250 s) is typical for sample No. 2 (Silagerm 8030, MСNT 3%, bronze 10%). For sample No. 3 (Silagerm 8030, MCNT 3%, aluminum 10%) at alternating current, the shortest time to reach the operating mode (140 s) is typical. The operating modes of heaters on alternating and direct current are different, which is associated with the formation of morphological and structural properties in composites that affect the flow of electric current of various types. All samples are characterized by a mode in which the current decreases and after 140-360 s is set to the operating mode corresponding to the heat balance, in which this current is spent to create a heat flow to heat the plant material and compensate for heat losses to the environment. It has been established that the operating mode of heaters based on elastomers modified with MCNT is characterized by the time interval for reaching the operating mode from 140 to 350 s, which exceeds the value for ceramic heaters based on barium titanate (BaTiO3). But the operating temperature is more stable and does not change over time (under constant heat exchange conditions). The use of elastic matrices makes it possible to form effective IR heating systems for technological processes of processing plant materials.

Developing an infrared-assisted solar drying system using a vertical solar air heater with perforated baffles and nano-enhanced black paint

In the present study, it is aimed to improve the performance of a solar drying system (SDS) utilizing ZnO nano-enhanced absorber coating and infrared heating system. In the first stage of this work, different geometrical configurations of the main heating system of the SDS which is a vertical solar air heater (VSH) have been numerically analyzed. According to the numerical findings, VSH with perforated type baffles gave the best performance results. Then, the determined configuration has been manufactured and combined with a drying chamber. Moreover, two other modifications have been applied to the system including an infrared heater and nano-enhanced black paint. In other words, the experimental part of this research contains three SDS types including a conventional SDS, a SDS with infrared heater and a SDS with infrared heater and ZnO nano-enhanced absorber coating (combined usage of two modifications). The mean thermal and exergetic efficiencies of the VSH analyzed within the scope of this work were attained between 53.54–65.12% and 9.94–14.32%, respectively. Moreover, combined use of infrared heater and nano-enhanced absorber coating material in the VSH decreased the drying time period as 43.75% when compared to the unmodified SDS.

The CHIMERA facility development programme

The CHIMERA fusion technology facility will enable testing of large in-vessel component modules under reactor-like conditions of combined in-vacuum thermal power density and magnetic field. With an integral large superconducting magnet and a PWR-like water loop, CHIMERA is also ideally placed for experiments on liquid metal breeding blanket prototypes. Facility construction is underway at the UKAEA site in South Yorkshire. The superconducting magnet is fully wound and terminated, and the bespoke pulsed magnet power supply has been delivered. Even before construction and commissioning is complete, a parallel and supporting research and development programme is in progress and is reported here. A bespoke infrared heating system has been developed, capable of applying 0.5 MW/m2 to component surfaces up to the size of the ITER test blanket module first wall. The modules of this heater are highly specialised and designed to endure the high magnetic forces from the CHIMERA static and pulsed magnets. CHIMERA will feature a range of diagnostics, including load cells to measure static and pulsed magnetic forces, and induced current sensors, all of which have been tested to confirm acceptable operation in the pulsed magnetic field. Manufacture of the test mock-up to be used for facility commissioning is underway. Testing will be enhanced with simulation ‘digital twin’ capability, and a development project is now producing first virtual test results, informing commissioning of the CHIMERA device.

Effect of elevated CO2 and temperature on maize resistance against the Asian corn borer

AbstractThe increasing atmospheric CO2 concentration and temperature has altered the plant‐insect interactions. However, little is known about the intrinsic mechanisms between plant resistance and insect survival strategies under the combined conditions of elevated CO2 and temperature. This study investigated the effects of elevated temperature alone and in combination with CO2 enrichment on the nutrition and resistance of maize (Zea mays L.) to the Asian corn borer (ACB) (Ostrinia furnacalis [Guenée]) and feeding, survival, and physiological response of ACB over 2‐year growing seasons. The maize plants were grown in free‐air CO2 enrichment connected by infrared heating system with the ambient (control), ~4.0°C increase in air temperature (ET) and ET together with ~700 ppm concentration of atmospheric CO2 (ETEC). Elevated CO2 alleviated the effect of ET on total non‐structural carbohydrates (TNC)/N in maize, and thus ETEC did not change this parameter. ETEC enhanced the defensive enzyme activities in maize. Elevated CO2 enhanced the ET effect on increased total phenolics content in maize. ET and ETEC increased the expression levels of the jasmonic acid (JA) defence‐related genes and JA content in maize. Above insect resistance‐related secondary metabolism in maize was enhanced by ACB damage. Except for amylase, ET and ETEC had no effect on the digestive enzyme activities and food intake of ACB, but enhanced its protective enzyme activities. ET and ETEC decreased the survival rate, overwintering larval body weight and fecundity, increased supercooling point of ACB fed on maize. These findings demonstrate that the combination of elevated temperature and CO2 did not influence the nutritional metabolism, but enhanced insect resistance‐related secondary metabolism of maize, which could alleviate the occurrence and damage of ACB in maize under the context of future climate change scenarios.

Design of low-energy consumption hybrid dryer: A case study of garlic (Allium sativum) drying process

As part of improving energy efficiency and quality of dried product, a hybrid infrared dryer was constructed by combining infrared (IF) and hot-air heating (HAD) systems and can be used to dry fruits and vegetables. This hybrid drying system is composed of hot-air drying and infrared heating system and was tested by drying garlic slices (3 mm) at 0.7 m/s using three temperatures of 40, 50, and 60 °C and infrared heating intensity of 1500, 2000, and 3000 W/m 2 . The Newton, Page, and Wang & Singh models were used to predict the moisture ratio (MR) and the results show that all the tested models exhibited MR prediction in garlic. The hybrid infrared dryer was efficient in energy consumption by conserving energy by 533–552% when compared with HAD drying system. Also, there was significant (p<0.05) improvement in rehydration capacity, allicin content and colour when compared with HAD and IF drying techniques. In effect, this hybrid dryer could provide a better drying alternative for industrial applications as it has the potential of saving energy and improving the quality of dried products.

Infrared Heating for Rapid and Localized Shape Transformations of Additively Manufactured Polymer Parts

Four-dimensional (4D) printing is an advanced application of additive manufacturing which enables additional shape transformations over time in response to external stimuli. For appropriate shape transformation, dedicated materials such as shape memory polymers or 3D printers supporting multi-material printing have been used. Recently, a facile 4D printing method was developed which used a fused filament fabrication type 3D printer and a plain thermoplastic filament. This method used the anisotropic thermal deformation of the FFF-printed part to intentionally impose anisotropy by programming orthogonal printing paths, which resulted in thermoresponsive shape transformation upon a thermal stimulation. While the previous studies used convective heating as the thermal stimulus and thus required a long heating time of more than 10 min, this study uses an infrared (IR) heating to enable rapid thermoresponsive shape transformation. An infrared heating system was developed which included an optical focusing unit, a masking unit and a movable heating stage. To investigate the speed of shape transformation, IR heating was performed on a rectangular strip (60 × 6 × 1.6 mm) and the relevant shape transformation time was compared with the previous convective heating result. The shape transformation proceeded rapidly, and after 70 s formed a fully-closed circular shape, corresponding to the 1/10 reduction compared with the convection type heating (more than 13 min). The IR heating was further applied to 2D-to-3D shape transformations of 2D star-shape and flower-shape specimens. For each specimen, a profiled mask was used to selectively irradiate IR on predefined regions and thus to localize the relevant thermoresponsive shape transformation. The global and local IR irradiations were then compared in terms of heating capability and the variability in shape transformations.

A greener approach to impart multiple functionalities on polyester fabric using Schiff base of vanillin and benzyl amine

Schiff base (SB) of vanillin with benzyl amine has been prepared by a simple route by reducing the organic solvents and making the process greener resulting in significant amount of yield. The vanillin itself and its synthesized SB have been integrated into polyester (PET) fabric using high temperature high pressure (HT-HP) dyeing machine at 120 °C using infra-red (IR) heating system to impart multiple functionalities on to the fabric. PET fabric treated with SB has shown antimicrobial activity of more than 90% against E coli (Gram-negative) bacteria; registered good ultra-violet protection factor (UPF) as well as imparted attractive color with increased antioxidant activity. Thus, the study has successfully demonstrated SB as a novel green finishing agent to PET textiles to impart antimicrobial and UPF activity along with certain coloring effect with good fastness. Although vanillin itself integrated on PET textiles has shown antimicrobial effect but after single wash its properties diminishes very quickly which makes it not much useful and the material needs further tweaking to make it a fit for durable finishing agent on PET. The study exactly demonstrated the same wherein it has been proven that SB can potentially replace other hazardous chemicals used in the industry to create functionalities on textiles. Cytotoxicity analysis of the treated fabric also reveals that the compound is biocompatible and completely safe for use.

CFD MODELING OF MODULAR POULTRY BREEDING

Intensive poultry farming in industrial conditions is carried out mainly in rooms equipped with mechanical ventilation systems. The frequency of body heat stress is constantly increasing due to poor regulation of microclimate parameters, which affects the productivity of birds. Infrared heating systems can be an alternative to traditional heating systems for poultry houses. The purpose of the study is to modernize the method of keeping poultry based on the principle of its sectional breeding. For high-quality and simultaneous breeding of different ages of poultry a modular keeping is offered. The heating system of module is a panel infrared heater. It is intended for local heating of technological area. Design dimensions of the module were determined for reasons of qualitative course of technological process, namely the stocking density of poultry. For a better representation of temperature regime in the module CFD modeling was performed. Fields of velocities, pressures and temperatures were obtained. The air temperature near poultry in the module reached 18.6 ºC, and the average velocity did not exceed 0.75 m/s.

Способ модификации конструкции хлебопекарной печи на основе принципов принудительной конвекции

The problem of producing environmentally friendly and harmless food products requires not only high-quality raw materials, but also the modification of technological equipment for baking. The main direction of the modification is to reduce the loss of nutritional value of the feedstock in the production of bread, resource saving and environmental friendliness. The implementation of these directions when modifying the design of bread machines is possible based on the application of the principles of desegregation and forced convection. In order to ensure the required parameters of the technological process for the production of bread from whipped yeast-free dough in a modified design of the apparatus, onstructive solutions for improving the baking chamber are proposed. The obtained density indicators of specific isobaric heat capacity, thermal conductivity and dynamic viscosity with an infrared heating system for a dough piece made from whipped yeast-free dough make it possible to determine and correct the characteristics of technical devicesincluding the design of the apparatus. The results of experimental studies of the proposed designs of devices for the production of whipped yeast-free dough and bread baking allow us to conclude that the proposed technical solution provides a reduction in baking time by 27–32 %, heat loss by 23–25 %, energy resources by 17–19 %, material consumption by 20–25 %. The proposed design changes ensure the production of environmentally friendly bakery products through the use of physical principles that do not destroy the molecular structure of the feedstock.

Preliminary Cryogenic Layering by the Infrared Heating Method Modified with Cone Temperature Control for the Polystyrene Shell FIREX Target

The infrared (IR) heating method for a central ignition target with spherical symmetry is modified for the axisymmetric Fast Ignition Realization EXperiment (FIREX) target. The challenge is that the FIREX target pretends to be a thermally spherical shell. Our previous simulation studies (A. Iwamoto et al., Fusion Sci. Technol. 56, 427 (2009), A. Iwamoto et al., J. Phys.: Conf. Ser. 244, 032039 (2010)) have shown that the combination of volumetric heating in a fuel and cone temperature control has the potential to finish a uniform fuel layer. We have developed the IR heating system, dedicated to the FIREX target, with exclusive cone temperature control. The ability of solid fuel layering was examined by using an 826 µm polystyrene (PS) shell with a gold cone of 1.2 mm in length instead of the 500 µm FIREX target for easy observation. The system could control the profile of a solid fuel layer in the PS shell target. Eventually, the solid layer with the best sphericity of 92% was formed, and the RMS roughness of the inner surface was 44 - 49 µm in modes 1 to 100 and 14 - 26 µm in modes 5 to 100.

Microstructural Evolution of 9CrMoW Weld Metal in a Multiple-Pass Weld

9CrMoW steel tubes were welded in multiple passes by gas-tungsten arc welding. The reheated microstructures in the Gr. 92 weld metal (WM) of a multiple-pass weld were simulated with an infrared heating system. Simulated specimens after tempering at 760 °C/2 h were subjected to constant load creep tests either at 630 °C/120 MPa or 660 °C/80 MPa. The simulated specimens were designated as the over-tempered (OT, below AC1, i.e., WT-820T) and partially transformed (PT, below AC3, i.e., WT-890T) samples. The transmission electron microscope (TEM) micrographs demonstrated that the tempered WM (WT) displayed coarse martensite packets with carbides along the lath and grain boundaries. Cellular subgrains and coarse carbides were observed in the WT-820T sample. A degraded lath morphology and numerous carbides in various dimensions were found in the WT-890T sample. The grain boundary map showed that the WT-820T sample had the same coarse-grained structure as the WT sample, but the WT-890T sample consisted of refined grains. The WT-890T samples with a fine-grained structure were more prone to creep fracture than the WT and WT-820T samples were. Intergranular cracking was more likely to occur at the corners of the crept samples, which suffered from high strain and stress concentration. As compared to the Gr. 91 steel or Gr. 91 WM, the Gr. 92 WM was more stable in maintaining its original microstructures under the same creep condition. Undegraded microstructures of the Gr. 92 WM strained at elevated temperatures were responsible for its higher resistance to creep failure during the practical service.

Experimental studies of infrared burners of a micronizer functioning with biomethane

To increase the shelf life of grain crops, heat treatment with a micronizer is used. For testing, a block heating burner with radiant nozzles was developed and improved to determine the permissible content of carbon dioxide in the purified biogas when fed to a gas infrared heating system with burners. The operability of the infrared burner ГИК-8 on purified biogas with a CO 2 content of 0.234.0% has been established. The temperature of the heating surface of the ГИК-8 burner on gas mixtures with a CO 2 content of 18-34% is 900-950˚С, which does not differ from the nominal temperature when operating on natural gas. The possibility of ignition of a cold burner ГИК-8 at 33% CO 2 content in the purified biogas has been determined.

New infrared heat treatment approaches to dry and combat fungal contamination of shelled corn

AbstractCommercial application of infrared (IR) heat has been hampered by a lack of readily available data adaptable to high‐throughput (HT) drying requirements in the grain processing industry. This study evaluated the effectiveness of a continuous flow IR heating system to simultaneously dry and decontaminate corn over various drying bed thicknesses (1.5, 2.7, and 4.5 cm). Additionally, impacts of intermediate tempering treatment and variation of IR emitter angle (zero [E‐0] and 30 [E‐30] degrees) on drying and decontamination of the corn were determined. Although IR heating was able to dry and decontaminate corn at the initial moisture content (MC) of ≈21% wet basis (w.b.), moisture removal was most effective at the least bed thickness (1.5 cm). At 1.5 cm bed thickness, a safe storage MC (&lt;14%) was achieved after 15 min of IR heating. At all the bed thicknesses, IR heating with intermediate tempering resulted in higher fungal inactivation than IR heating without tempering. Infrared heating of corn at 1.5 cm bed thickness plus tempering resulted in a total fungal count (TFC) reduction of 3.1 and 4.6 log CFU/g using IR emitters at E‐30 and E‐0° angles, respectively. However, increasing the bed thickness to 2.7 cm resulted in a TFC reduction of 4.8 and 4.6 log CFU/g using E‐30 and E‐0, respectively. Infrared heating using E‐0, compared to using E‐30, accelerated TFC reduction when corn samples were dried at 1.5 cm bed thickness. These results could help guide the design of HT corn drying and decontamination systems.

Enhancing energetic and economic efficiency of heating coal mines by infrared heaters

Purpose. To increase the energy and economic efficiency of heating coal mines with infrared heaters through energy saving measures, taking into account the dynamics of the discount rate. To achieve this goal, the task was to conduct an energy audit of the heating system of the mine during its reconstruction according to an improved method, taking into account the dynamics of the discount rate and measures that are not feasible at the same time. Methodology. When using infrared heating systems, local heating of the working area is provided. As a result, the necessary temperature conditions in the mines are maintained and there is a possibility of creating a local microclimate. A multifactorial experiment was performed and the research results were graphically and analytically described. Furthermore, the method of energy audit, taking into account the effect of complex interaction of factors and the dynamics of the degree of discount, is applied. Findings. According to the results of the experiment, a nomogram of the temperature regime of the irradiation area with an infrared heater was constructed, which was approximated by the analytical dependence. The optimal profit from the introduction of energy-saving technologies during operation is EUR 379.2 under the following conditions: replacement of the heating system from stationary to variable with automation; installation of a different number of infrared heaters NL-12R with power Q 1200 W each; application of the effect of complex interaction of factors. Originality. The conducted energy audit of the radiant heating system with the use of infrared heaters during the underground reconstruction showed that non-stationary heating is efficient because it saves energy and has the lowest payback period. Practical value. The expediency of using infrared heaters in variable mode in both energy and technical and economic aspects has been proved. These measures will provide comfortable conditions in the mine and have a significant economic effect.