Heating Period Research Articles

Special Features of Convective Drying of Dispersed and Fibrous Materials with Periodic Heat Supply

Special Features of Convective Drying of Dispersed and Fibrous Materials with Periodic Heat Supply

Chemical and isotopic genesis of fine and ultra-fine aerosols in the coastal urban atmosphere.

Chemical and isotopic genesis of fine and ultra-fine aerosols in the coastal urban atmosphere.

Граничні можливості централізованого теплопостачання щодо використання електроенергії відновлюваних джерел

The article presents the results of a study on the use of electricity from solar and wind power plants by the centralized heat supply of Ukraine for its direct conversion into heat using electric heat generators (electric boilers and heat pumps). The marginal possibilities of the centralized heat supply of Ukraine regarding the use of this heat energy, which is the purpose of this work, have been assessed. To carry out the analysis, a calculation model was created, limitations were set, and methodical approaches were developed to determine the necessary initial data. Research was conducted for heating and non-heating periods. In the non-heating period, four different options for using electricity from solar and wind power plants for its conversion into heat were simulated. The results of the calculations showed that as of 2021, during the heating period, the demand for thermal energy significantly exceeds the possibilities of its production by electric heat generators that consume electricity from solar and wind power plants. The limit value is the total capacity of solar and wind power plants of 18.514 MW. In the non-heating period, all the electricity produced by solar and wind power plants cannot be fully consumed by electric heat generators of centralized heat supply due to the fact that there will be a surplus of heat energy of 1736.4 thousand MWh. 21.7 million m3 of water will be needed to accumulate this amount of thermal energy with seasonal thermal accumulators. With an average volume of a seasonal heat accumulator of 60,000 m3, you will need about 360 of them. In the conditions of the dense construction of urban settlements, it is unlikely to build such a number of seasonal thermal accumulators. The most likely option is the partial use of electricity from solar and wind power plants by electric heat generators of centralized heating, electrolyzers for hydrogen production and product cooling systems. At the same time, heating boilers on fossil fuel will work together with electric heat generators, which will ensure the reliability of heat supply. Keywords: solar power plants, wind power plants, centralized heat supply, electrothermal generators, electricity.

Devising a methodology for assessing seasonal thermal energy generation by a combined heat source

The object of this study is the process of calculating the distribution of heat generation and energy consumption by heat sources. The task addressed was estimating the seasonal heat generation by a combined heat source with an air heat pump. A methodology for quantifying the seasonal heat generation and energy consumption by sources as part of a combined heat source with an air heat pump has been devised. This methodology makes it possible to take into account different bivalent operation schemes, variable mode of the heating system, and different electricity tariffs. The ability to take these factors into account increases the accuracy of the results but also increases the complexity of the calculation process. In order to automate the calculation using the devised methodology, an algorithm was built, and an example of its implementation was demonstrated. The results show that the distribution of seasonal heat generation largely depends on the values of the bivalent point temperature and the heat pump shutdown temperature. In addition, they demonstrate the dependence of the calculated amount of heat consumed during the heating period and the distribution of its generation between sources on the number of the last heating periods taken into account. With a decrease in the number of past heating periods taken into account, the amount of heat consumed per season gradually decreases and the share covered by the heat pump increases. This indicates a gradual decrease in the duration of low temperatures in winter and proves the importance of relevance of the climatic data used for analysis. The methodology devised in this study makes it possible to determine the appropriate ratio of thermal power of heat sources in a combination and increases the accuracy of calculating the payback period of equipment

Certification of Buildings and Measures of Energy Efficiency Class Improvement

Nowadays, the problems of energy efficiency and energy saving are found in different spheres of construction. Various energy-efficient technologies are used to reduce energy consumption. The certification process is carried out at different stages: design, construction and reconstruction, which is leading to improvement of energy efficiency of the building, etc. The article covered the European standards that determine the coefficient of seasonal use of thermal energy (E), as well as the current energy efficiency classes of the Republic of Armenia. Both the EU and the Republic of Armenia have tightened requirements for enclosing structures. In Armenia, the thermal characteristics of enclosing structures can be improved by 15% to 41% depending on the degree-day value of the heating period. The value of the specific characteristic of thermal energy depends on climatic conditions, space-planning solutions, orientation of the building, etc. The standardized value of this characteristic for heating and ventilation varies from 0.414 to 0.336 W/m<sup>3</sup>°C depending on the area of the heated building and its number of storeys. And for a residential building with an area of 1000 m<sup>2</sup> and more, the non-standardized value does not depend on the number of storeys of the building. Classes of energy efficiency of buildings are determined by the value of the deviation of the calculated value of the specific characteristic of the consumption of thermal energy for heating and ventilation of the building from the standardized one. For determining the class of energy efficiency, the article considers a one-story residential building without thermal insulation and with thermal insulation of enclosing structures. To increase the energy efficiency class of a building from D to C, it is necessary to improve the thermal characteristics of the enclosing structures, i.e. reduce heat loss of buildings by 30% or more.

Droughts in the High Continental Climate of Central Asia

Drought, one of the manifestations of emergencies, is a serious problem for Central Asia. Experts estimate that more than 70 per cent of the region's territory is considered vulnerable to natural disasters. Droughts are less frequent than floods, but affect more people. Over the past decade, 60 per cent of the population exposed to extreme weather events has been affected by drought. The most tangible impact of drought is on agriculture and food security in the region. Droughts are expected to become more frequent in Tajikistan, Turkmenistan and Uzbekistan due to projected temperature increases and longer periods of extreme heat and evaporation in areas with lower precipitation. In establishing drought monitoring and early warning systems in Central Asia and adapting drought prediction models, the monitoring of climate indicators and the availability of a rich and deep database of years is an important link. The purpose of this work is to monitor the probability of drought occurrence depending on the meteorological conditions of the Kafirnigan River basin in Tajikistan. The formation and dispersion zones of the Kafirnigan River differ significantly in their meteorological characteristics. The monitoring of droughts in the area of the river's formation and dispersion and their comparison with meteorological conditions allows establishing the existence of certain regularity between them. The results of such dependencies can form the basis for the development of drought early warning systems. A characteristic feature of the drought indices (SPI and SPEI) in the southern Tajik lowlands is their decreasing nature and the significant difference in the trends of change. Differences between SPEI-6 and SPI-6 are due to potential evapotranspiration (PET), which is determined by the difference between precipitation and evaporation. The similarity between SPEI and SPI in winter is reasonable because this is the period when PET tends to have the lowest ratio to precipitation, resulting in a functional approximation of SPEI to SPI. According to the same principles, the largest difference is observed in November, which covers the period from June to November, when PET is highest in relation to precipitation. It is found that for the period 1950-2023, monthly mean precipitation values are significantly lower and temperatures are higher than the climatic norm of the southern Tajik lowlands, leading to negative values of mean annual SPEI and SPI and favoring the occurrence of drought.

Arginine accumulation suppresses heat production during fermentation of the biocontrol fungus Beauveria bassiana.

Beauveria bassiana (Bb) is one of the most widely used biocontrol agents, and its products constitute more than one-third of the global market share of fungal insecticides. Solid-state fermentation (SSF) is widely used in the production of Beauveria bassiana (Bb) because of its economic practicality and high production efficiency. However, the heat generated during fermentation can sharply reduce both the yield and quality of Bb, and current industrial methods to mitigate high temperatures during fermentation are inadequate, leading to increased production costs. Thus, exploring the underlying mechanism of how heat is produced by Bb is crucial for improving the SSF procedure and yield. This study employed multiomics data analysis of Bb during SSF to explore the relationships between fungal fermentation and environmental factors. We found that the heat production period for SSF was 12 hours to 48 hours post-inoculation. To further explore the underlying mechanism during this heating period, we identified 454 temperature-correlated metabolites (TCMs) and 1,994 temperature-correlated genes (TCGs). Annotations of the above TCMs and TCGs revealed significant enrichment in the arginine biosynthesis pathway; specifically, the expression level of glutamine synthetase, a TCG, decreased with fermentation time, whereas the expression levels of the TCGs L-arginine and L-glutamine increased with fermentation time, and glutamine synthetase and L-glutamine in the arginine biosynthesis pathway cycle produced the end product L-arginine. Furthermore, when the substrates of the SSF were treated with exogenous arginine, the temperature peak of the SSF significantly decreased with increasing concentration of exogenously added arginine.IMPORTANCEA large amount of experimental evidence from the field has shown that Bb is an irreplaceable mature product that protects the health of our agriculture and ecosystem. In addition to high efficiency and host extensiveness, low cost is a critical merit that makes Bb products frequently used in the field. However, the growing cost of power and labor in the Bb industry, especially the SSF procedure, has significantly increased the price of its products, thus restricting the use of Bb in the field. This study not only fills the theoretical knowledge gaps concerning the molecular basis of the interrelationship between Bb and the fermentation environment during SSF but also provides an economical and applicable strategy (the addition of arginine to the fermentation media) to further lower the cost and increase the yield of Bb during SSF at the industrial level.

Thermal environment modelling - assessment of Fanger model’s usability in the smart building supplied from renewable energy sources

Abstract The proper design of smart buildings, usually powered with renewable energy sources, should ensure that the indoor conditions are comfortable and users experience thermal comfort throughout the year. The existing model of thermal comfort comes from the 60’s/70’s and was the basis for the ISO 7730 Standard. It utilizes the concept of the PMV (Predicted Mean Vote) and PPD (Predicted Percentage Dissatisfied) indicators. The current paper compares the actual expressions of people (as indicated by them in the anonymous questionnaires) with the PMV/PPD values calculated according to the Standard. Therefore, 76 people aged 20 to 40 were examined during the heating period. The temperature in the rooms ranged from 21.6°C to 24.1°C, and the insulation of the clothes of the examined people ranged from 0.40 to 1.39 clo. Differences between these values have been discussed and conclusions have been drawn as to the usability of this thermal comfort model in smart buildings, which still seem to be a novelty in Central European countries and data on their thermal comfort performance is still quite modest.

Influence of multi-stage infrared heating on the efficiency and uniformity of asphalt pavement hot in-place recycling

To enhance heating uniformity and efficiency in the hot in-place recycling process of asphalt pavements, a multi-stage infrared intermittent heating method is developed through the creation of a physical and mathematical model for collaborative heating, analyzed using the finite element simulation software. This method is compared with a traditional single-step heating approach, with a focus on evaluating heating effects under various parameter configurations. Findings indicate that continuous and single-step intermittent infrared heating can cause asphalt pavement ignition and coking, resulting in severe asphalt aging. In contrast, multi-stage intermittent heating reduces maximum pavement surface temperatures as quenching intervals increase, though at the cost of prolonged total construction time and reduced heating efficiency. For two-step intermittent heating, a consistent cyclic heating period lowers the peak pavement temperature and reduces the heating time but significantly lengthens the total construction duration, thus impacting the overall efficiency. When assessing the construction quality, heating rate, efficiency, and energy consumption, the multi-stage intermittent heating method 1 demonstrates superiority over alternative approaches.

Manufacturability and Performance Study of Triply Periodic Minimal Surface Air-to-Air Heat Exchanger

Abstract The study tests 3D printability, heat transfer characteristics and pressure drop of two types of triply periodic minimal surface heat exchanger in order to develop new flow principles for compact heat exchanger design. Various generic plate heat exchanger designs are also tested to compare to the printed alternatives. Geometry variations for heat exchangers and laboratory testing air recuperators are modelled in SolidWorks software and manufactured mostly by UV LCD and FDM additive manufacturing methods. Digital light processing printing method has been found to be most successful in printing the TPMS structures, while using photopolymer materials. Literature studies conclude that the most promising structures are Schoen’s gyroid and Schwarz-diamond surfaces, which have been modelled and tested in several variations. Using these results, full size gyroid and Schwarz-D structure heat exchangers have been modelled, manufactured and tested. The results are compared and analysed to study the effect of advanced surface designs in heat transfer efficiency. The obtained results can be used in compact air-to-air thermal recuperator development as well as other low pressure heat exchanger applications, as the printed TPME heat exchangers outperform the plate heat exchangers in similar dimensions.

Effect of Green Roofs on the Thermal Environment of Prototype Broiler Houses

The management of thermal environments in animal production facilities presents significant challenges, requiring continuous adjustments to meet animals’ physiological needs. This study evaluated the effects of green roofs on the thermal environment and comfort indices in small-scale poultry house prototypes, comparing facilities with and without green roof installations. The research tested various roof types (ceramic, fiber cement, and metal) combined with emerald grass (Zoysia japonica) green roof systems. Parameters measured included air temperature, relative humidity, internal roof surface temperature, Temperature and Humidity Index (THI), Black Globe Humidity Index (BGHI), Human Comfort Index (HCI), and Thermal Radiation Load (TRL) under both open and closed conditions. Results showed that green roofs reduced indoor air temperature by up to 2.4 °C in open prototypes and 10.6 °C in closed prototypes during peak heat periods. In combinations using green roofs with fiber cement tiles, internal roof surface temperature decreased by 24.0 °C in open prototypes and 27.0 °C in closed configurations. The implementation of green roofs resulted in THI reductions of 2.3 and 8.1 units in open and closed prototypes, respectively, BGHI decreases of 2.8 and 11.3 units, and TRL reductions of 21.0 W/m2 and 74.0 W/m2. HCI measurements confirmed improved thermal comfort conditions with green roof installations in both settings. This study concludes that green roofs effectively enhance the thermal environment by reducing bioclimatic indices during hot periods while maintaining stable conditions during cooler weather, thereby improving overall thermal comfort in animal facilities.

Utilization of low-potential thermal power plant energy sources

THE PURPOSE. Development of technical solutions for the utilization of secondary boiling steam to reduce losses of thermal energy, steam and condensate of CHP plants. METHODS. Comparative studies of disposal options were conducted, and several schemes for condensation of low-potential energy sources were proposed. The economic effect of the proposed technical solutions for the utilization of steam emissions from CHP plants is calculated. RESULTS. To determine the technical characteristics of the auxiliary equipment, calculations were carried out on the amount of coolant. During the winter period of operation of the installation - a source of steam emissions, with a minimum evaporation rate of 2.5 t/h - about 10.99 t/h of cooling water (mains water) is needed for cooling and subsequent condensation of steam; with a maximum evaporation rate of 5 t/h - 21.99 t/h of cooling water (mains water), respectively. According to the calculation results, the OVA-16 shell-and-tube heat exchanger was selected, the heat exchange surface area of which is 16 m2. When implementing the proposed technical solutions for the disposal of evaporation, the economic effect was calculated, which amounted to: - with a minimum evaporation consumption of 2.5 t/h for heating mains water, during the heating period (on average 245 days) 82320-98020 rubles; with a maximum evaporation consumption of 5 t/h) 164640-184044 rubles, respectively.

EFFECT OF AGNIKARMA IN AMSAMARMA ABHIGHATA - TRAUMATIC PERI-ARTHRITIS OF THE SHOULDER JOINT- A CASE REPORT

Periarthritis of the shoulder joint is a condition characterised by disabling pain, inflammation, stiffness, and restriction of both active and passive movements of the shoulder joint. Among the factors suggested for the cause of the disease, trauma is found to be one of them. Traumatic periarthritis of the shoulder joint may be correlated with Amsamarma Abhighata due to similarity in clinical features such as Bahukriyaharam and Stabdabahutha. Acharya Susrutha mentioned that Agnikarma is effective in Ruja pertaining to Sira, Snayu, Sandhi and Asthigata Vikara. Amsamarma is a Snayu Marma and Acharya Susrutha has mentioned Dahanopakarana like Kshoudra, Guda, Sneha for Agnikarma in Sira, Snayu, Sandhi, Asthi gata Vikara. In this study, a female patient 60 years was treated with Agnikarma to assess the effect of Agnikarma with Tila Taila in Amsamarma Abhighata - Traumatic periarthritis of shoulder joint. Agnikarma has properties like Vatakaphahara, Ushna, Sookshma, and Ashukari Guna, which help relieve pain and stiffness instantly. Snigdha dravyas have deep heat penetration capacity with a greater latent heat period. It is helpful in musculoskeletal disorders and can be done on an OPD basis. The assessment was done on subjective parameter, pain and objective parameter like range of movements(Abduction). The patient was assessed before and after treatment. Follow-up was done on the 7th, 15th and 30th day for 1 month.

Energy Performance Assessment on Vertical Greening Systems with Green Roof in Hot Summer and Cold Winter Regions Based on Long-term Experimental Data

Energy Performance Assessment on Vertical Greening Systems with Green Roof in Hot Summer and Cold Winter Regions Based on Long-term Experimental Data

Increased angiopoietin-1 improves nailfold capillary morphology in patients with systemic sclerosis

Increased angiopoietin-1 improves nailfold capillary morphology in patients with systemic sclerosis

Numerical Study of heat transfer performance of geothermal pile-foundation heat exchanger in ground source heat pump system

Abstract To evaluate the thermal conductivity performance of geothermal pile-based heat transfer units utilized within ground source heat pump (GCHP) frameworks, we developed physical models encompassing both solitary pile-based heat transfer devices and assemblies of such units. A thorough examination was conducted into the heat exchange mechanics and efficacy of these devices, covering both refrigerating and warming operational modes. For the purpose of simulating the heat transfer processes within a 3×3 array of energy piles, a real-world scenario involving an office building situated in Nanjing was adopted. Utilizing DeST software, we calculated the annual dynamic building load, which spans the cooling period, the heating period, and the two intervening transition periods. Following a simulated ten-year operational lifespan, it was noted that the average soil temperature exhibited an increase under conditions of non-equilibrium. The outcomes of this study closely mirror real-world conditions and can be harnessed as a theoretical foundation for the design and deployment of pile-foundation heat exchangers within GSHP systems.

Research on Remedial Measures Based on the Differences in Atmospheric Particulate Matter Pollution Status between Heating and Non-Heating Periods in Harbin City

Research on Remedial Measures Based on the Differences in Atmospheric Particulate Matter Pollution Status between Heating and Non-Heating Periods in Harbin City

Range and accuracy of in-plane anisotropic thermal conductivity measurement using the laser-based Ångstrom method.

High heat fluxes in electronic devices must be effectively dissipated to prevent local hotspots, which are critical for long-term device reliability. In particular, advanced semiconductor packaging trends toward thin form factor products increase the need for understanding and improving in-plane conduction heat spreading in anisotropic materials. The 2D laser-based Ångstrom method, an extension of traditional Ångstrom and lock-in thermography techniques, measures in-plane thermal properties of anisotropic sheet-like materials. This method uses non-contact infrared temperature mapping to measure the thermal response to periodic laser heating at the center of a suspended sample. The spatiotemporal temperature data are analyzed via an inverse fitting algorithm to extract thermal conductivities in the in-plane orthotropic directions that best adhere to the governing heat conduction equation. Using this algorithm, we present an approach to simultaneously fit data across multiple heating frequencies, which improves measurement sensitivity because the thermal penetration depth varies with frequency. The accuracy of this technique is assessed by tuning experimental parameters such as sample dimensions and heating frequency. A standardized workflow is proposed for measuring unknown materials and for processing the data, including filtering out regions influenced by laser absorption and heat sink boundary effects. Numerical simulations validate the method across a wide range of thermal conductivities (0.1-1000W m-1 K-1) and material thicknesses (0.1-10mm), with accuracy demonstrated for anisotropy ratios up to 1000:1. Experimental measurements on isotropic and anisotropic materials agree well with the benchmark values. Ultimately, standardization of this technique supports the development of engineered anisotropic heat-spreading materials for thermal management and packaging applications.

Phthalate plasticizer affects blood electrolytes, hormones, and reproductive parameters of black Bengal goats.

The present study looked at how electrolytes, hormones, and postpartum reproductive physiology were affected in black Bengal goats (BBGs) when they were fed a phthalate mixture (PHA). Twenty clinically healthy BBGs, 1-2 months pregnant, aged 6-8 months with a body weight of 10-12 kg, were chosen and randomly allocated to two experimental groups (n = 10 each). The BBGs of the treatment group (n = 10) were administered a standard ration containing a mixture of Diethyl Phthalate, Dibutyl Phthalate, Di-isobutyl Phthalate, and Dipropyl Phthalate phthalate. The non-treated control group (n = 10) received the goat ration without any phthalates up to parturition. Blood samples were taken from experimental pregnant goats just before parturition to analyze serum hormone and electrolyte levels. The levels of sodium, chloride, and calcium were reduced (p < 0.05) in PHA-exposed goats than in the non-exposed control group. No significant difference was observed in potassium and phosphorus levels between the two groups. PHA-exposed goats showed significantly decreased levels of estrogen, progesterone, luteinizing hormone, and thyroxin compared to control goats (p < 0.05). Postpartum reproductive traits, such as gestation length, postpartum heat period, abortion rate, and retained placenta, were significantly (p < 0.05) prolonged in BBG that had been exposed to PHA. PHA plasticizer exposure during pregnancy affects the electrolytes, hormones, and postpartum reproductive physiology of BBGs.

ОПРЕДЕЛЕНИЕ ОПТИМАЛЬНОГО ДИАМЕТРА ТЕПЛОПРОВОДА ПУТЕМ РЕШЕНИЯ ОПТИМИЗАЦИОННОЙ ЗАДАЧИ

At the design stage of engineering networks, an important issue remains the choice of diameters of the pipeline system with minimal capital investments for transporting the working medium from the source to consumers. The purpose of the study is to determine the diameter of the pipeline, which achieves maximum savings in money for the transportation of heat carrier for specified conditions. Based on the classical laws of hydraulics and heat transfer, a computational equation has been obtained using software calculations, which allows determining the diameter of a heat pipeline with an optimal ratio of monetary costs for electrical and thermal energy. The final formula takes into account such important operational parameters as heat carrier flow, pipeline roughness and local hydraulic resistances, tariffs for thermal and electrical energy, etc. Using the example of the main pipeline section of the district heating system located in the city of Vologda (Russian Federation), a software solution of the equation proposed in the article is obtained. It was found that with a mass flow rate of 32.9 t/h, the optimal diameter of the steel electric-welded pipeline is 76×3 mm. Taking into account the current tariffs for thermal and electric energy, the monetary costs of transporting the heat carrier for the heating period of the year amounted to 4912 rubles per 1 cubic meter of pipeline. For comparison, with a pipeline diameter of 57×3 mm, the unit cash costs turned out to be 7887 rubles, and with 89×3.5 mm – 5524 rubles. For the case considered in the article, the dependence between the optimal diameter of the pipeline and the mass flow rate of the heat carrier is obtained.