Search

With the rapid increase of solar module wattage from about 300 W to above 650 W, it is important to study the impact of high wattage on the hot spot risk. In this paper we use finite element analysis (FEA) and experiments to analyze the effects of various designs on the hot spot temperature of high wattage solar modules. Design factors include cell size (156.75 mm, 166 mm, 182 mm and 210 mm), the number of cells per bypass diode and cell shape (full cell, half cell and one-third cells). The simulation data is in good agreement with the experiment, and shows a clear trend: increasing the number of cells per bypass diode increases the hotspot temperature at most, increasing cell size leads to a moderate but considerate increase, and cutting a cell into smaller pieces lowers the hot spot temperature under certain conditions. The developed thermal balance model shows that the change in the power density and effective thermal resistance at the hotspot cells are the keys to the trend. This research proves the effectiveness of using finite element analysis (FEA) to study the hotspot risk, and points out a new direction for how to control the hotspot risk of high wattage solar modules with larger solar cells.

The baking capacity of a box-type solar oven made from disused recyclable elements was studied and based on the equations that govern the its behavior, a thermal balance of its main elements was proposed for the determination of its thermal efficiency as a function of time. A mathematical model is also presented with the purpose of estimating the temperatures reached by the studied. The device has been tested for two configurations, unloaded and loaded. Tests of stagnation, sensible heat, baking of six cakes (4.500 g) were carried out; two lasagna (1.600 g) and a load of assorted foods (3.200 g). The results showed that the absorbing surface and the air reached maximum temperatures of 144.2 °C and 124.5 °C respectively, obtained in the no-load test. The cakes were baked in 80 min; the lasagna in 34 min and the simultaneous loading of a pizza, six breads, two cakes, and ten breaded, in 65 min. The stagnation and sensible heat tests presented the following figures of merit, F1 = 0.075 °Cm2/W and F2 = 0.534 °Cm2/W, respectively. The mathematical model showed good agreement between theoretical and experimental results. It was also demonstrated the viability of the solar oven for the production of several foods simultaneously, being able to be used as a food factory, which could be commercialized by people with low purchasing power, to generate employment and income

The purpose of this work was to analyze the thermal balance of easily assembled premises of different types and sizes during the periods of low average daily temperatures. The research was conducted during the winter period of 2020–2021 in the Kyiv region. The used material was easily assembled premises of different types and sizes: easily assembled ones without insulation elements; with elements of warming and premises with deep-litter. In each of the studied premises were kept 400 dairy cows. The studies were performed during two periods: the first period had ambient temperatures from -10 to -14.9 °C and the second one from -15.0 °C and below. In our studies, the average daily temperature (during the ambient temperature from -10 to 14.9 °C) in easily assembled premises with the use of insulation elements was 6.20 and 5.31 °C higher than in premises without insulation and deep-litter. A similar trend was observed during the period of lowering the ambient temperature up to 15 °C and below. Thus, the advantage of the premises without insulation constituted 6.28 °C, and of the premises with deep-litter per 5.84 °C, respectively. It was found that keeping in easy-to-assemble premises with insulation elements, the consumption of free thermal energy from the whole herd during the experimental periods was lower compared to the keeping in a boxing cowshed and a cowshed with deep litter. This is due to the smaller range of fluctuations in the average daily temperature in a room with insulation elements. A similar trend was observed for energy consumption through enclosing structures and for moisture evaporation and, accordingly, total heat consumption. In general, heat deficiency was observed during the keeping of cows in the investigated premises of easily assembled type at negative temperatures (-10–14.9 and -15 °С and above). Accordingly, the thermal balance of the premises was negative. The highest values of heat balance among easily assembled premises in both research periods were observed for keeping in rooms that used insulation elements.

The material properties of the rubber compounds, which are highly dependent on temperature, have a vital role in the tire behavior. A comprehensive study on the effect of the rubber properties on tire performance, for different temperatures, as well as different road conditions is required to adequately predict the performance of tires on ice. In this study, a theoretical model has been developed for the tire-ice interaction. The temperature changes obtained from the model are used to calculate the height of the water film created by the heat generated due to the friction force. Next, the viscous friction coefficient at the contact patch is obtained. By using the thermal balance equation at the contact patch, the dry friction is obtained. Knowing the friction coefficients for the dry and wet regions, the equivalent friction coefficient is calculated. The model has been validated using experimental results for three similar tires with different rubber compounds properties. The model developed can be used to predict the temperature changes at the contact patch, the tire friction force, the areas of wet and dry regions, the height of the water film for different ice temperatures, different normal load, etc.

The work investigates the thermal balance of a low ampere arc. The dependences of the thermal flow in the cathode and anode on the amperage, the diameter of the non-consumable electrode and the length of the arc gap are shown.

R1234yf is considered as a better alternative for R134a (the conventional refrigerant) due to its low global warming potential value, while its usage is limited because of its flammability. The flammability of any flammable refrigerant can be reduced by adding dilutants that are inert. Two methods (group contribution method and thermal balance method) were used to estimate the minimum inerting concentration (which decides the flammability zone) of the binary mixtures (refrigerant + dilutant). It was observed that the group contribution method and the thermal balance method predicted minimum inerting concentration of the refrigerant mixture (refrigerant + dilutant) with an absolute error of more than 50% and 8%, respectively. Therefore, a modified thermal balance method is proposed in this study to estimate the minimum inerting concentration and found that the proposed method predicts the values with reasonable accuracy when compared with the available experimental data. Further, the minimum inerting concentration for the dilutants R125 and R245fa (that are not experimentally known) with R1234yf is estimated. The results indicated that R227ea has better inert effect with R1234yf when compared to other dilutants (R125, R134a and R245fa) considered in this study. It was also found that the critical inerting concentration for R1234yf is 36.5%.

A high temperature gradient within a solid oxide fuel cell (SOFC) stack is considered a major challenge in SOFC operations. This study investigates the effects of the key parameters on SOFC system efficiency and temperature gradient within a SOFC stack. A 40-cell SOFC stack integrated with a bio-oil sorption-enhanced steam reformer is simulated using MATLAB and DETCHEM. When the air-to-fuel ratio and steam-to-fuel ratio increase, the stack average temperature and temperature gradient decrease. However, a decrease in the stack temperature steadily reduces the system efficiency owing to the tradeoff between the stack performance and thermal balance between heat recovered and consumed by the system. With an increase in the bio-oil flow rate, the system efficiency decreases because of the lower resident time for the electrochemical reaction. This is not, however, beneficial to the maximum temperature gradient. To minimize the temperature gradient of the SOFC stack, a decrease in the bio-oil flow rate is the most effective way. The maximum temperature gradient can be reduced to 14.6 K cm−1 with the stack and system efficiency of 76.58 and 65.18%, respectively, when the SOFC system is operated at an air-to-fuel ratio of 8, steam-to-fuel ratio of 6, and bio-oil flow rate of 0.0041 mol s−1.

Three numerical models have been developed to investigate the thermal balance in a 500 kA aluminum reduction cell. The hooding efficiency, ventilation uniformity, and exhaust gas flowrate (EGF) uniformity of the cell were studied by using an upper cell thermoflow model and a dual-ductline flow model, and the effects of changing the EGF on the thermal balance were investigated using a slice thermoelectric model. The results of the models were compared with industrial measurements taken under similar conditions, revealing good agreement that demonstrates the validity of the use of numerical models to study the impacts of the EGF on the thermal balance. The cell showed a high hooding efficiency, good ventilation uniformity (deviation range − 4% to 5%), and more uniform thermal field when using the high-performance duct and dual-ductline system. The potline could exhibit good EGF uniformity (deviation range ± 5%) in running cells. Through these advantages, the problems of dust accumulation in the duct and gas leakage at the tapping end (TE) were solved effectively, and the EGF was decreased from 10,607 Nm3/h to 8308 Nm3/h without reducing the cell hooding efficiency. The results were transferred to industrial practice by upgrading the duct system of a 500 kA potline, achieving a total energy saving of 233 kWh/t-Al, of which about 80 kWh came from the gas treatment center and 153 kWh from the reduction cells.

The practice shows availability of an electro plasma method polishing. The lack of a method, namely impossibility of its application for processing extended grooves and apertures is known. Creation of a special equipment and revealing of optimum modes have allowed to receive the given roughness on the named surfaces on products from cuprum.

When droplet moving in the steam-water separator, the gas pressure will decrease due to flow resistance and the liquid-vapor equilibrium at the droplet surface will be broken. The droplet evaporates continuously as a result. The fast evaporation mechanism and thermal balance evaporation mechanism are presented for the droplet evaporation at cases of pressure variation. The droplet phase change model due to pressure variation is formulated. Subsequently, the effects of pressure difference on the droplet evaporation characteristics are analyzed. The ratio analysis of the two mechanisms is conducted. The droplet evaporation map over the ratio of two mechanisms is drawn. The numerical results indicate that the pressure difference significantly influences the droplet evaporation characteristics. Under most conditions, the droplet evaporation characteristics are dominated by the combined action of two mechanisms. For large pressure difference and small droplets, the fast evaporation mechanism dominates the evaporation process, and vice versa. With increasing pressure difference between the droplet and the surrounding environment, the droplet evaporates faster and the percentage of fast evaporation mechanism decreases gradually. The present work can lay the foundation for further investigation on the moving droplet evaporation.

Based on the physical thermal balance equation of the microbolometer under pulse current bias, the microbolometric theoretical infrared responsivity is given out in this paper. The operating temperature of the microbolometer during the pulse current bias period is theoretically discussed and analyzed, from which the microbolometric theoretical infrared responsivity expression is derived for high-speed microbolometric focal plane array. The microbolometric theoretical infrared responsivity expression reveals some key factors to decide the infrared sensitivity of the microbolometric focal plane array and has been successfully verified through an experimental microbolometric focal plane array. The microbolometric theoretical infrared responsivity expression is theoretically strict and can be utilized for future microbolometric focal plane arrays with some high-performance characteristics parameters such as high-speed and small-pixel.

[EN] The passive thermal control of a satellite consists of establishing the necessary thermal parameters involved in the process of heat transfer by radiation and conduction in order to delimit the range of temperatures to which the different components will be exposed. If the obtained range implies temperatures that the elements of the satellite are unable to cope with, therefore, an external control is demanded. This work deals with the programming of the equilibrium thermal problem taken into consideration a backward-implicit scheme. The algebraic mathematical approach for steady-state and transient analysis are implemented in Matlab scripts. In addition, the work analyzes the influence of different coating materials on the passive thermal control of a benchmark spacecraft reported in the literature. The problem under scope considers the characteristics of a low Earth Orbit: the solar, albedo and planetary radiation, the radiation coming from other isotherm surfaces of the same satellite, the heat conduction and, finally, the radiation of these isotherm surfaces to the outer space. The procedure implemented is based on a feasible matrix formulation and results avoid the numerical instabilities prevalent in the forward-explicit approach, moreover, it enables further parametric and sensitivity analysis. Regarding the coating materials influence on the thermal response, the most relevant results evidence that thermal surfaces can guarantee the desirable range of temperature in a spacecraft. We confirm that certain material properties like the absorptance, emittance and its relation (absorption coefficient) are essential in the thermal response of the system. Nevertheless, these thermal properties do not influence in the same way. It is shown that the effect of the emittance is lower than the absorptance., The authors acknowledge the Agencia Estatal de Investigaci6n for the financial support received through the project DPI2017-89197-C2-2-R and the Generalitat Valenciana for the Programme PROMETEO 2016/007. The authors declare that they have no conflict of interest.

Collector leakage current is an important electrical parameter in insulated gate bipolar transistor manual, which reflects its forward blocking characteristics. In this paper, based on IGBT structure and PN junction reverse current principle, by analyzing the components of collector leakage current, the variation characteristics at different temperature stages are obtained, and the thermal failure mechanism caused by positive feedback of IGBT junction temperature and collector leakage current is analyzed from the perspective of thermal balance. Finally, the collector leakage current of IGBT is tested experimentally, the failure mechanism of thermal balance is verified, and the chip failure characteristics are observed.

The paper deals with the influence of the thermal state of the machine on its function and product accuracy. The results of the experimental measurement on a particular machine are presented and consequently a virtual simulation of the thermal state of the working space depending on the time of its operation of the machine is performed. Model examples for changed boundary conditions are calculated with respect to the possibility of reducing energy consumption while maintaining a constant thermal state of the machine. Based on the simulation of the thermal state a structural analysis is performed to determine the effect of thermal conditions on the clearance of the ram guiding.

The time-dependent evolution of the energy transfer into gas heating in the afterglow of pulsed CO2 and CO2–N2 glow discharges produced in cylindrical tubes at low pressures (1–5 Torr) is theoretically investigated, by developing a self-consistent model that couples the time-dependent gas thermal balance equation with the vibrational kinetics. The modelling predictions are in good agreement with recently published experimental data on gas temperature, obtained via time-resolved in situ Fourier transform infrared spectroscopy. The cooling of the gas in the afterglow is found to be strongly dependent on the thermal conductivity and the wall temperature. It is verified that wall and volume deactivation of CO2 vibrationally excited species influences the gas heating along the afterglow, in different proportions depending on the pressure of the gas. The time-resolved contributions of each of these cooling and heating mechanisms are discussed in detail. The new results bring an additional validation of a set of mechanisms and rate coefficients for vibrationally-energy transfers previously proposed.

Oxygen plays a duel role on mixture safety as a heat source and a heat sink. For the variable oxygen in a compartment (a type I problem), oxygen level in background air determines the upper limit of the fuel. For the oxygen in a fuel stream (a type II problem) in air, the oxygen will change the thermal properties of the fuel like a diluent or a fuel. Here both problems are solved with the thermal balance method. A new method, the flammable resistance method, can solve the type II problem more easily. It is equivalent with the thermal balance method, but with a perfect form like the Le Chatelier's Rule. Both methods are useful in assessing the danger of a flammable fuel stream containing oxygen.

When rated current of the transformer windings is higher than the critical current of the used HTS tape, it is necessary to use parallel tapes. As a result, the currents flow in individual parallel tapes is uneven, whose effect is flow of the equalization currents. The compensation of that current could be obtained through mechanical transposition of the tapes in proper “transpositioners.” In order to test the applicability of the “transpositioners,” a transformer model as well as the cooling system of the HTS winding, based on two cryocoolers, was designed. In order to check whether all elements of the cooling system has been properly designed, and thus the system will be able to obtain and maintain a temperature of 77 K, thermal balance of the system was performed by analytical calculations as well as by a numerical analysis. Finally, the cooling system was build and prepared for experimental investigation.

The present paper investigates the magnitude of the corrected thermal resistance of the slab on the soil in the case of a usual dwelling building in Romania. For computational purposes, the CIMPSPAT software [8] was used; it uses the very accurate numerical method of the thermal balance written in the nodes of the computational grid, according to the provisions of SR EN ISO 10211:2008 [7]. The research was performed for eight variants of thermal insulation layer, with thicknesses varying from 5 to 40cm. When buildings are designed, in general, only the one direction thermal resistances are considered, without taking into account the regulations in Standard C107/2010 [6] and Order no. 2641/2017 [3], which requires specific minimal values for corrected thermal resistances, including thermal bridges, for various construction elements (external walls, external joinery, floors over the last level, slabs on the soil, etc.) [1]. For the slab over the soil, for instance, a thermal insulation layer made of extruded polystyrene of 5, rarely 8 or 10 cm is generally used [1]. This research, performed on a common dwelling building in Romania, aims at finding out the minimal thickness of the thermal insulation layer that meets the requirements of the Norms in C107/2010 [6] and Order no. 2641/2017 [3], that specifies a minimal value for the corrected thermal resistance of the slab over the soil of 4,50 m 2 ·K/W [2].

The insulation effect of ceramic coating in a turbine blade is of great importance for the service of engine in the field of aviation industry. Fabricating microstructure in the thermal barrier coatings (TBCs) is considered to be able to enhance the thermal insulation effect. In this study, the traditional three-layer structure, containing ceramic top coat, bonding coat and substrate, is firstly simplified into a double-layer structure, where only ceramic layer and substrate are left, for analyzing the thermal insulation. Afterwards, the thermal insulation effect of the designed microstructure in the bonding coat of the three-layer structure is further studied. Column-like microstructures, filled with hollow ceramic microspheres in the interspace, are designed to improve the thermal insulation effect. The size parameters of the designed microstructure were optimized. The existence of the designed microstructure can significantly prolong the efficiency of thermal barrier coatings. The insulation temperature between the heating surface and lower surface of the substrate can exceed 300°C and the thermal balance time has a big improvement of 240 s, more than 50%, than the traditional TBCs structure. Compared with the TBCs structure without microstructure, the designed microstructure can significantly improve the insulation temperature of more than 110°C. Keywords: Thermal barrier coatings, Microstructure, Insulation effect, Turbine blade

The article describes a power efficient technology, allowing to preserve and maintain the heat content in a continuously cast bar at the production line “Continuous Casting Machine – Rolling Mill”. It considers a possibility of obtaining the maximum heat content in the continuously cast bar by means of rational cooling schedules in the secondary cooling zone. In order to maintain the achieved heat content in the bar, it is proposed to utilize heat insulation of the bar in the air cooling zone prior to its cutting-to-length. The article describes the design of the heat insulating shell in the CCM process scheme and the materials to be used for it. To analyze the interaction of heat flows between the bar and the shell in the heat insulation zone, the author has made a thermal balance of this zone. A mathematical model of the concast bar cooling with due consideration of the heat insulation zone and its implementation by means of numerical methods is described here. The application of numerical simulation has allowed to predict rational cooling schedules for the continuously cast bar and to determine the heat content of the bar at the exit from the continuous casting machine with respect to the heat insulation. According to the results of the simulation, there have been plotted the charts of temperature distribution along the CCM length, comparing the air cooling of the bar and its thermal conditioning in the heat insulation zone. These results confirm the effectiveness of utilizing heat insulation for maintaining the maximum heat content of the bar, which makes it possible to reduce the power costs for its heating prior to the rolling.

A new approach to the analysis of the heat work of glassmaking furnaces is proposed. A generalized equation of the thermal balance of a furnace at the boundaries between the smoke stack and the glass melt channel is obtained. Boundary conditions on the temperature for media whose heat content defines the cost items of the thermal balance are formulated. It is shown that the heat rate (specific consumption of heat) in melting of 1 kg glass influences the percentage content of the cost items of the generalized thermal balance. A calculation of the thermal balance of the melting area of a 320 t/day container glass furnace with specific consumption of heat 1000 kcal/kg is carried out.

Waveguide heating due to transmission of microwave signals is studied. Mathematical models are developed to evaluate heat liberation, and differential equations of thermal balance are derived with allowance for different working conditions of waveguides. The results prove the necessity of the further study of the effect of heat liberation in waveguides on strength and functional characteristics.

To study the temperature rise characteristics of the valve-controlled shock absorber, the heat generation and heat dissipation model of the shock absorber is established based on the theory of hydrodynamics and thermodynamics, and the corresponding thermal balance equation is analyzed from the perspective of heat generation and heat dissipation. The impact of vibration velocity, outer diameter, thickness and length of reservoir cylinder, and wind velocity on its temperature rise characteristics have been investigated. Finally, it is found that temperature after thermal balance will decline with the increase of outer diameter, length of reservoir cylinder and wind velocity and grow with the increase of vibration velocity and thickness of reservoir cylinder.

In order to study the damping characteristics of valve-controlled shock absorber. According to the heat generation and dissipation process, the thermal balance model of the shock absorber was established from the perspective of energy conservation. The damping curves of the shock absorber at four impact velocities were obtained on the basis of experiments. By comparison, it is found that the difference value of the thermal decay rate hits its peak which is the result of mechanical friction at low speed. Meanwhile, the experimental results demonstrate that the indicator diagram is relatively full without obvious distortion. Finally, the study indicates that the shock absorber still has great vibration damping characteristics after thermal decay.

For mechanical properties temperature dependence test in high temperature rising rate, a method of heating specimen using two-sided laser irradiation is proposed. Simulation about different materials in laser heating about different laser power density and different laser duration were conducted. The result shows that two-sided laser irradiation can obviously improve the temperature field of the specimen in normal laser irradiating. The simulation shows that this method is better for metal than composite materials because of the heating pyrolisys may have a bad influence on the thermal balance. Based on this method, the tensile strength temperature dependence of the T700 carbon fiber laminate was obtained. The result is close to the parameter obtained in electrical mechanical machine by furnace heating. The research can make a reference for the mechanical properties test of composite materials or metal in high temperature with high heating rate.

Cell lining design must ensure the presence of solidus isotherm in the upper refractory layer to maintain the pot thermal balance. The depth of melt penetration in lining depends on the endurance of refractory layer. The melt penetration causes the mineralogical transformation of refractory layer, which acts as a barrier for further penetration. However, the barrier resistance is dependent on the chemistry of transformed phases of refractory material. This study outlines an on-field investigation of cell lining materials. A detailed autopsy of a high amperage cell has been performed to identify the probable causes of reduced cell life. The autopsy results exhibit substantial deterioration of powdered dry-barrier refractory layer at an early age of cell life, leading to premature cell failure. The greater percolation of vitreous phases through the dry-barrier could be attributed to its pulverulent nature resulting in higher permeability than the refractory bricks of similar composition.

Measurement and analysis of the basic physical properties for a thermoelectric module (TEM) is important to design a high-performance TEC (thermoelectric cooler) system. A thermal balance equation based method is proposed to determine the figure of merit, electrical resistance, and maximum temperature difference of a TEM. A STM32 based measuring device is designed and operated at the room-temperature. It is found that the maximum measuring relative error is about 3%. The design provides potential to manufacture a high repeatability and stability measuring device for TEM.

The paper investigates the influences of misalignment on the lubrication performances and lubrication regimes transition of water lubricated bearing. A modified lubrication model considering the influences of journal misalignment is proposed in the paper. Surface topography and thermal balance effects are incorporated in the theoretical model. Influences of misalignment with different surface roughness and radial clearances on lubrication performances are explored systematically. Experimental results verified the correctness of the lubrication model. Results indicate that the maximum pressure and shear stress increase, the minimum film thickness decreases and the eight dynamic coefficients increase with the misaligned angle. The region of boundary lubrication arises, the region of mixed lubrication and hydrodynamic lubrication decreases. Misaligned angle deteriorates the lubrication performances on the interface. Research results have guiding significance for further study of influences of surface topography on the structure design and optimization for such bearings.

Thermal balance of an aluminium reduction cell is indicated by a stable freeze profile with acceptable thickness. One of the main factors which contributes to a stable freeze profile, where the freeze is not extending beyond the anode shadow is the cell lining design. In this study, a 3D quarter cell thermo-electric model of an 86 kA cell was developed using ANSYS. The model was validated with the plant measurements and subsequently utilized to evaluate the influence of carbon seam on the freeze profile in the aluminium reduction cell. The simulations were conducted both at design amperage and at increased amperage. It was observed that the impact of the seam shape was significant on the freeze profile and seam shape modifications could be investigated for achieving a stable freeze profile and for amperage increase programs. A nearly vertical seam provided a stable freeze profile both at design and higher amperages compared to conventional bevel shaped seam.

The consumption of hot metal in slag preparation and slag-coating application in the converter may be reduced by scrap heating. The thermal equivalents of the coke additions and coke consumption in smelting to ensure the required metal temperature at tipping are determined. The basic principles for converter technology with preliminary scrap heating are developed, and experimental data are obtained regarding the efficiency with which the carbon-bearing fuel (coke) is used, so as to improve the thermal balance of the converter process and the final characteristics of steel production.

The paper presents methodology of measuring the values which characterize the thermal balance in a horticultural facility. Thermal transmittance through a plastic tunnel cover and the ratio of solar radiation energy conversion into heat were analysed in detail. The research was carried out in real time with closed ventilators, where no plants were cultivated during the tests. The utility surface area was 144 m2, the cover was 289 m2 and its volume was 508 m3. Basing on the standard relations, first of all, thermal transmittance through a cover was measured. The ratio was measured with the use of standard criteria equations. Then, a correlation equation, which makes its course dependent on the climate parameters (the wind speed and temperature difference between the interior of the facility and its surroundings), was found. Knowing the course of the ratio in the function of the climate parameters, the value of the ratio of solar radiation conversion into heat stored in the facility was measured. Both parameters (thermal transmittance and solar radiation conversion ratios) were calculated from the thermal balance equaition where the change of the energy stored inside the facility was compared to the heat losses through a cover (for thenual transmittance) and the profit (in case of solar radiation conversion). For the obtained values, using the non-linear estimation procedure (with quasi-Newtom method with maintenance of the correlation coefficient of 0.001) the change of both ratios in the function of easily measured parameters of climate inside and outside the facility was found out. In the investigated conditions, the average value of thermal transmittance through a cover was 5.32 W·m−2·K−1, and the solar radiation conversion into heat was 0.36. The values and their course from the climate parameters inside and outside the facility may be used for controlling the amount of supplied heat and location of ventilators.

Every new car should be equipped with the catalyst, which limits the amount of harmful chemical compounds such as NOx, CH and CO emitted to the air. Auto catalyst consists of the ceramic or metallic carrier, on which is the layer with Platinum Group Metals playing catalytic role. There are many methods using for recovery those valuable metals from spent auto catalyst, however evry of those methods have some limitations. Proces described in the article is the modified method of metal collector, which used magnetohydrodynamic pump. Rotary electromagnetic field generates in the liquid metal rotary current, which as a consequence washing out the PGM metals from the ceramic carriers. Considering the possibilities of commercialization of the described method, the energy balance was made. From that balance the energetic efficiency of the unit was determined and the analysis of the temperature distribution was shown thermographycally.

A precise method for calculating segmented legs for thermoelectric generators in a one-dimensional approximation by the method of thermal balance with effective values of the thermoelectric parameters is proposed. This method allows one to accurately take into consideration the temperature dependences of the electrical conductivity, the Seebeck coefficient, and thermal conductivity. The effect of contact resistance on the resulting power-conversion efficiency is also taken into account. The procedure of segmented leg calculation is demonstrated, and a method of transitioning from leg calculation to thermoelement calculation is proposed.

The performance of a power battery is greatly affected by temperature. This paper optimized the power battery liquid-cooled system and put forward the way of adding fins to the liquid-cooled plate to improve the cooling efficiency of the thermal management system. In this paper, a liquid-cooled battery system model was established, and the thermal balance performance of the parallel liquid-cooled system was studied through numerical analysis. The results show that the parallel liquid-cooled system with an optimized shunt could maintain the maximum temperature of the battery system below 44.31 °C, and the temperature difference of the battery system could maintain at 3 °C, which could meet the temperature requirements of the power battery system.

Bath temperature stability is a very important parameter with which to evaluate pot thermal balance. In this paper, a transient thermo-electric finite element model of reduction cell is established to simulate the fluctuation curve of bath temperature under different alumina feeding rates and different energy inputs. The model results show that short-term fluctuation of the temperature curve is influenced by different alumina feeding rate under underfeeding and overfeeding, but the long-term fluctuation depends on whether energy input matches average feeding rate. If the difference between energy input and heat consumed by alumina reaches the latter&rsquo, s 10%, the temperature changes about 1.8 &deg, C after four cycles. Based on model results, the paper analyzes the relationship among alumina feeding rate, bath temperature fluctuation and heat balance. The matching of heat input and heat consumed by alumina is of crucial importance to maintaining bath temperature stability.

This paper describes a detailed thermal design scheme to ensure the low-temperature detection requirements of the solar X-ray and extreme ultraviolet imager (XEUVI) under complex external heat flux conditions. First, the structure, working mode and internal heat sources of the imager are introduced. Second, the thermal design scheme is proposed with a combination of active and passive thermal controls. Finally, a thermal balance test of XEUVI was performed in a vacuum environment. The test results showed that the CCD temperature ranged from -65.6°C to -56.3°C, the optical system temperature ranged from 12.9°C to 22.0°C, the frame temperature ranged from -4.6°C to 20.3°C, the motor temperature ranged from 1.0°C to 19.8°C, and the electrical box temperature ranged from -2°C to 38.8°C. The results of testing meet the requirements of the thermal control indices, and the thermal balance test verifies the correctness of the thermal design.

The structure arrangement and the spacing of cells are key factors related to the thermal safety of the Li-ion battery pack. To explore their effects on thermal performance of the cell module, a series of discharge tests on cell packs were carried out, and the temperature distribution were monitored along cells with various structure arrangements and cell-to-cell distances. Thereafter, the heat generation and heat dissipation of the cells were calculated based on the monitored temperature to quantitatively analyze the thermal balance. Results showed that the temperature of cells with ring structure rose faster than the other two cases with line and square respectively, and its maximum temperature was highest. Its temperature difference was up to 8.5 °C, and its discharge time was nearly 200 s less than the other two structures, which indicated its worst thermal performance. Increasing of cell-to-cell distance improved the thermal performance, while the improvement was rather slight once the distance is more than 7 mm. In addition, the heat transfer under different discharge rates were also discussed, which showed that the temperature rise was controlled by heat dissipation and generation for 1C and 3C, respectively, while controlled by their coupling effects at 2C.

Based upon the temperature data from the thermal balance test in vacuum environment, thermal optical analyses on a space optical remote sensor (space camera), aiming at investigating the thermal influences on the optical performance, were carried out. In this paper, the measured discrete temperature data were applied to obtain the integrated temperature profile of the camera, and the thermal distortions and optical performances with that temperature distributions were calculated, which was different from the general analyses procedure published in the open literatures. By the researches of inversion temperature field analyzing, thermal distortion analyzing, optical performance analyzing, and data comparing between simulation and test, it was indicated that temperature is one of the effect factors to the optical performance of this space camera. The results also indicated that the thermal distortion influences on the optical performance could be farthest restrained by controlling the temperature of the main structural and optical components under the design value.

Underground coal gasification (UCG) is recognized as an efficient mining technique capable of chemically converting the coal from deep coal seams into synthesis gas. Depending on the main constituents of the synthesis gas, chemicals, electricity, or heat can be produced at the surface. This paper provides a high-level graphical method to assist practitioners in developing preliminary gasification processes and experimental programmes prior to detailed designs or field trials. The graphical method identifies theoretical limits of operation for sensible gasification within a thermally balanced region, based primarily on the basic coal chemistry. The analyses of the theoretical outputs are compared to actual field trials from sites in the USA and Australia, with very favourable results. A South African coal is studied to determine the possible synthesis gas outputs achievable using various UCG techniques: controlled retractable injection point (CRIP) and linked vertical wells (LVW). For CRIP techniques, an important result suggests that pyrolysis, and subsequent char production, are important intermediate phenomena allowing for increased thermal efficiencies of UCG. The conclusion is that South African coals need to be studied for pyrolysis-char behaviour as part of any future UCG programme. The results also suggest that UCG with CRIP would be a preferred technology choice for Bosjesspruit coal where pyrolysis dynamics are important. Lastly, the use of CO2 as oxidant in the gasification process is shown to produce syngas with significant higher heating value.

The horizontal current in the metal pad is one of the important factors influencing the hydromagnetic stability in an aluminum electrolysis cell. The cathode structure with current flowing out of the cell from the bottom can almost eliminate the horizontal current and improve the cell stability. The anode to cathode distance can be reduced and the energy consumption is hence reduced. The present paper describes the computer simulation result of the cathode structure with current out from the bottom, the thermal balance and the hydromagnetic stability. The trial result of two 220 kA cells with current out from the bottom is also introduced.

‘Wet’ thermal insulation, defined as the thermal insulation when clothing gets partially or fully wet, is an important physical parameter to quantify clothing thermal comfort. As the water/sweat gradually occupies the intra-yarn and inter-yarn air voids of the clothing material, the clothing intrinsic thermal insulation will be diminished and, hence, contribute to the loss of total insulation. In cold conditions, a loss in total thermal insulation caused by sweating may result in an inadequate thermal insulation to keep thermal balance and eventually leads to the development of hypothermia and cold injuries. Therefore, it is imperative to investigate the effect of clothing fit and moisture content on clothing ‘wet’ insulation. In this study, the ‘wet’ thermal insulation of three two-layer clothing ensembles was determined using a Newton thermal manikin. Four levels of moisture content were added to the underwear: 100, 200, 500 and 700 g. The clothing apparent ‘wet’ thermal insulation under different testing scenarios was calculated and compared. A third-degree polynomial relationship between the reduction in ‘wet’ thermal insulation and the moisture content added to underwear was obtained. Further, it was evident that the clothing fit has a minimal effect on the apparent ‘wet’ thermal insulation. The findings may have important applications in designing and engineering functional cold weather clothing and immersion suits.

In order to utilize the low-calorific value gases, oxy-combustion technology is generally used to burn the diluted fuel mixture more efficiently, cleanly and safely. Here the thermal balance method is tailored to check the fuel mixture flammability with the help of theoretical flammability diagrams and non-dimensional HQR diagrams. Specifically, the contributions of diluent/oxidant/temperature are checked. Even with limited experimental data, they are found to be a powerful tool to understand the mixture flammability, since they are based on simple principles of energy conservation. This approach provides the foundation for fine-tuning safe operation parameters related to oxy-combustion technologies.

Solar liquid collector/regenerator (C/R), combining the functions of solar collector and regenerator of absorbent solution together, can be effectively utilized in solar energy-driven liquid desiccant cooling systems. Based on thermal balance of the glazing of solar C/R, a group of modified heat and mass transfer models, validated by experimental results to reflect solution regeneration process more truly, were put forward in this paper. Numerical simulation showed only preheating air stream, keeping an equal humidity ratio, did raise the performance of solar C/R, but preheating solution increased the regeneration efficiencies to reach twice that of preheating air stream. There occurred optimum mass flow rates for both air stream and solution film reaching 36–48 kg m−1 h−1 and 4∼6 kg m−1 h−1 respectively for solar C/Rs of 3∼6 m long. As for effect of the length of solar C/Rs, the regeneration efficiency ηr reached a maximum value at about 4 m and shorter or longer solar C/Rs failed to increase solution regeneration efficiencies.

The thermal deformation of reflecting optical system in the ambient temperature affects the system performance greatly. Based on the results of thermal balance test, the paper has made a full analysis to the deformation of reflecting optical system on the high-low temperature using the finite elemernt method,so as to validate whether the optical system meet the requirement of optical image design and temperature. This method can combine the thermal optical analysis and thermal balance test data effectively ,and therefore the most actual thermal optical anslysis model can be obtained to guide the concept and optimization of reflecting optical system.

Результатом роботи є обґрунтування доцільності впровадження результатів моделювання рівнянь теплового балансу, складених для активної частини розподільчого трансформатора напруги, на стадії його завершального і уточнюючого етапу проектування. Активна частина знаходиться в середовищі трансформаторного масла, а тепловіддача здійснюється теплопередачею та конвекцією. Математична модель теплового балансу відповідає еквівалентній тепловій схемі заміщення, складеної з двох суміжних вузлів зі стоками тепла - узагальненої обмотки і феромагнітного стрижня та третього суміжного з ними вузла - рухомої речовини з масла, яке додатково контактує з оточуючим середовищем нескінченної теплоємності. Рішення рівнянь отримані для середнього значення температур обмотки, стрижня магнітопроводу і масла в функції часу, що дозволяє встановити очікувані їх значення упродовж роботи трансформатора і, особливо, з нерівномірним графіком його навантаження, а також здійснювати обґрунтований вибір магнітної індукції в стрижні магнітопроводу і густини струму в обмотках за показником припустимих в них температур нагріву.

A three-dimensional finite element model of the front cover die casting made of aluminum alloy was established by PRO/E and PROCAST software. Thermal balance formation of die casting die and temperature curves of the die cavity surface at different locations were analyzed. The results showed that the nearer the distance from die cavity surface, the greater temperature fluctuation. The thermal fatigue depth of the front cover die casting die was only 0.9mm.

A three-dimensional finite element model of the aluminum alloy front cover die casting die was established by PRO/E and PROCAST software. Thermal balance forming of die casting die and the influence of pouring temperature on thermal fatigue depth of die cavity surface were analyzed. The results showed that the temperature amplitude increased with the decrease of distance from die cavity surface. The higher the pouring temperature is, the bigger the thermal fatigue depth will be.