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The thermal performance of a lithium-ion battery module comprising three cells contained within a casing was investigated at discharge rates of 3C and 5C with three different cooling strategies: forced air, phase-change material (PCM), and a hybrid system using a combination of forced air and the PCM. Three levels of fan speed (5000 rpm; 7000 rpm; and 9000 rpm) for cooling air flow were considered. A numerical simulation of heat transfer was performed using the ANSYS Fluent software. The electrochemical modelling of a battery was developed based on the NTGK approach, and the phase-change phenomenon was treated as an enthesis–porosity problem. The composite PCM, aluminum metal foam embedded in n-octadecane, had better heat dissipation performance than forced air convection. The PCM is significantly more effective at heat dissipation than forced air. Interestingly, when using a hybrid cooling system that combines forced air and a PCM, although it meets the operational requirements for Li-ion batteries in regard to maximum temperature and temperature uniformity at a 3C discharge rate, the airflow appears to have a negligible effect on thermal management and yields an indiscernible change in temperature. This can be attributed to a complex flow pattern that developed in a casing as a result of the suboptimal design of the inlet and outlet. Further studies will be required for the optimal positioning of the inlet and outlet, as well as the effectiveness of combining liquid cooling methods. [ABSTRACT FROM AUTHOR]

High heat flux dissipation from the Lithium-ion battery pack of hybrid electric vehicles is one of the major concerns in the automotive sector, since it directly affects the performance and it may also lead to permanent failure. Among various thermal management systems, forced air cooling is most favorable due to its light weight, compactness, lower cost, and design flexibility. In the present work, a battery thermal management system with the two types of vortex generator in the coolant passage has been used to enhance the performance. A numerical model has been developed in commercial code to investigate the performance of the delta winglet and circular protrusion type vortex generator. Apart from that, both types of vortex generator have been compared in terms of various parameters such as pressure drop, weight, and maximum temperature. From the results of the simulation, it has been observed that both vortex generators performed better at the attack angle of 30° in comparison to the attack angles of 45° and 60°. Furthermore, it has also been found that the cooling system with protrusion as the vortex generator has performed better in terms of thermos-hydraulic performance compared to the cooling system with the delta winglet vortex generator. In addition to that, the protruded system is lighter in weight compared to both the plain and delta winglet systems, and is recommended. [ABSTRACT FROM AUTHOR]

The thermal performance of a lithium-ion battery module comprising three cells contained within a casing was investigated at discharge rates of 3C and 5C with three different cooling strategies: forced air, phase-change material (PCM), and a hybrid system using a combination of forced air and the PCM. Three levels of fan speed (5000 rpm; 7000 rpm; and 9000 rpm) for cooling air flow were considered. A numerical simulation of heat transfer was performed using the ANSYS Fluent software. The electrochemical modelling of a battery was developed based on the NTGK approach, and the phase-change phenomenon was treated as an enthesis–porosity problem. The composite PCM, aluminum metal foam embedded in n-octadecane, had better heat dissipation performance than forced air convection. The PCM is significantly more effective at heat dissipation than forced air. Interestingly, when using a hybrid cooling system that combines forced air and a PCM, although it meets the operational requirements for Li-ion batteries in regard to maximum temperature and temperature uniformity at a 3C discharge rate, the airflow appears to have a negligible effect on thermal management and yields an indiscernible change in temperature. This can be attributed to a complex flow pattern that developed in a casing as a result of the suboptimal design of the inlet and outlet. Further studies will be required for the optimal positioning of the inlet and outlet, as well as the effectiveness of combining liquid cooling methods.

Patharnakh pear fruits were freshly harvested at the physiological maturity during second week of July and subjected to different precooling treatments, viz. Hydrocooling (HC), Forced Air Cooling (FAC) and Evaporative Cooling (EC). The effect of these methods on fruit shelf-life and quality attributes under ambient conditions was investigated during the year 2021–22 at Punjab Horticultural Post harvest Technology Centre, Punjab Agricultural University, Ludhiana, Punjab. In all treatments, temperature of fruit pulp was regularly checked with digital pulp thermometer until a constant temperature was accomplished. Thereafter, the fruits were packed in corrugated fibre board boxes of 2 kg capacity and stored at ambient conditions (28–32°C and 70–80% relative humidity). The stored samples were assessed, periodically, at 5 days interval till 20 days for physiological and biochemical parameters. The results of the study revealed that FAC maintained lower physiological weight loss, spoilage and retained higher fruit firmness, sensory quality score, juice TSS, total sugars, acidity, vitamin C and total phenolic content during storage compared to the control. This method is an effective approach for maintaining the post-harvest shelf-life of perishable pear fruits for about 15 days in comparison to 10 days in the untreated control fruits.

In this paper, the three‐dimensional fluid field‐temperature field coupled model of air core reactor is established, the detailed temperature field distributions of reactor can be obtained, and the reason about the temperature rise of reactor is significant increased when adding the rain cover is given by analyzing the flow velocity of fluid in the air ducts. Considering the natural air cooling no longer meets the temperature rise requirement of the reactor, the forced air cooling is performed by installing ventilation duct and fan at the bottom of the reactor, combined with the finite element method and central composite experimental design method (CCD), the influence of structure parameters of rain cover and ventilation duct on the temperature rise of reactor are analyzed, meanwhile, the response surface model is established, which reflects the relationship between the temperature of reactor and the structure parameter of rain cover and ventilation duct, and the optimal design parameters can be obtained based on the quantum genetic algorithm, the maximum temperature of the reactor is only 59.3°C, the difference between the prediction of response surface and simulation result is only 0.1°C, and the correctness of the optimization method is validated, which provides an important guiding significance for the safe and stable operation of reactor in the system. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The present study was conducted to study the potential of forced air cooling (FAC) on the post-harvest quality of litchi fruit. Bunches of 'Dehradun' litchi cultivar were collected after they reached full physiological maturity and they attained full rosy red color. After that, the fruits were destalked, stored in plastic crates, and treated with FAC for 2, 4, and 6 h. The fruits that had not been exposed to FAC were used as a control. Temperature of fruit pulp was regularly monitored with a digital thermometer for requisite period of time. Immediately after FAC treatments, the fruits were packed in corrugated fiberboard boxes (CFB) and stored in a walk-in-cold room maintained at temperature 2–3 °C and RH of 90–95%. The stored samples were evaluated periodically at weekly intervals up to 4 weeks for various physiological, biochemical parameters and enzymatic activities. The study demonstrated that, FAC (6 h) treatment effectively prolonged the storage life of litchi fruits for about 14 days over the control. The results revealed that litchi fruits subjected to FAC for 6 h maintained lower physiological loss in weight (4.30%), browning index (2) and improved pericarp color, retained higher firmness (108.5 g force), organoleptic score (6.80), TSS (18.85ºB), acidity (0.32), anthocyanins (0.25 ∆A/g FW), total phenols (234.95 mg/100 g) and also maintained the lowest PPO enzyme activity (156.60 unit/min/g FW) as compared to the control and other treatments. The aim of current study was that pre-cooling would delay the onset of senescence, preserving the quality of litchi fruits during storage and distribution. [ABSTRACT FROM AUTHOR]

The development of a battery-type loader is an important research direction in the field of industrial mining equipment. In the energy system, the battery will inevitably encounter the problem of heat dissipation when using high-power electricity. In this study, we took the power battery pack of a 3 m3 battery-type underground loader as the research object. The influence of single factors, such as the position of the air outlet of the battery pack, the size of the air outlet, the width of the separator, and the reverse plate, on the heat dissipation characteristics of the battery pack were studied. Then, a prediction model between the structural parameters and temperature was established using a radial basis function (RBF) neural network. This prediction model was then used as an adaptation evaluation model for global optimization through the multiobjective particle swarm optimization (PSO) algorithm, using which the optimal combination of structural parameters was obtained. The maximum temperature of the battery pack after optimization was reduced by 22%, compared to that before optimization, and the average temperature was reduced by 12.5%. Overall, the heat dissipation effect significantly improved. The optimization results indicate that the method proposed in this paper is feasible for use in optimizing battery heat dissipation systems in electric vehicles, thus providing a reference for research related to battery pack heat dissipation. [ABSTRACT FROM AUTHOR]

It is necessary to design a heat sink according to the losses of chips in the application of power chips to maintain the temperature of the chip junction at a low level. Since multiple power chips are distributed on the same heat sink, the surface temperature of the heat sink is unevenly distributed, the chips located at the air outlet need to withstand higher temperatures. In order to describe the surface temperature of the heat sink accurately, a novel comprehensive thermal resistance of the forced air cooling system for multi-power chips was proposed. A temperature rise test by a static var generator (SVG) prototype was designed to prove the accuracy of the model proposed. The thermal resistance error of the model proposed in this paper is only 2%. Comparing with two traditional thermal models, the accuracy of the novel thermal resistance model is improved by more than 20%.

To address the heat dissipation problem of the transmitting antenna in microwave power transmission system, an optimization design approach is proposed in this paper. Based on the characteristic analysis of the transmitting antenna, an accurate simulation analysis model of three-channel heat dissipation system is established using computational fluid dynamics simulations and experiments. The influences of the structural parameters of heat sink on the heat dissipation performance of the antenna under different indexes are analyzed using the orthogonal experimental design method, and the heat sink are optimized. The results show that the fin pitch of the heat sink is the main factor influencing the maximum temperature and the temperature standard deviation, while the fin height is the main factor affecting the average temperature. Compared with the original design, the optimized heat sink can significantly improve the heat dissipation performance of the transmitting antenna, and the maximum temperature, average temperature, and temperature standard deviation are reduced by 8 °C, 5.9 °C, and 2.1 °C, respectively. The transmitting antenna prototype test verifies the heat dissipation performance of the transmitting antenna with the optimized heat sink. Therefore, the presented approach is suitable for the optimization design of the heat dissipation system of array antennas.

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For the high power solar array simulator, the requirements such as high power, miniaturization and modularization are higher. In this paper the total power of the simulator is 2.4 kW with the chassis height is no more than 2U. The forced air cooling is adopted. The modular structure is used in the forced cooling system according to the electrical connection requirement. The chassis is divided into three parts, the linear, the multilevel and the Vicor module. And the independent cooling air duct system is set up for each part. The contractile air duct of the multilevel and the Vicor part are optimized mainly. The forced air cooling system with the optimization design can satisfy the high power density requirements of the simulator. The maximum case temperature of the components can be controlled under 88 ℃, and all the devices in the simulator can work safely and reliably. The results are verified by both finite element simulation and thermal test.

Solid-state thermoelectric refrigeration and heat pump systems can be integrated with battery packs in electric vehicles (EV) and hybrid electric vehicles (HEV) for effective thermal management in both hot and cold environments. Operating modes can be switched by changing the polarity of the input voltage to the thermoelectric system. In this paper, a new design of a battery pack is proposed which includes an acrylic battery container, copper battery holders, liquid cooling medium, and battery cells. This battery pack is integrated with a battery thermal management system (BTMS) which includes thermoelectric cooling (TEC) in combination with liquid and air circulations. The aim of the BTMS is to handle heat generation during operation of the battery pack. Heat, generated by the battery pack, is transported to the cold end of the TEC and then dissipated to the surrounding environment by a heatsink. Fundamental design optimization is carried out on a single cell first. System performance is then validated in the battery pack experiments. For the 40 ​V test, the proposed system reached approximately 20 ​°C lower when compared with only liquid cooling. In the 30 ​V power supply test, the battery pack temperature did not exceed 30 ​°C in a period of 5000 ​s. Furthermore, the battery pack temperature was under 60 ​°C at 3000 ​s during a continuous discharge condition with a 50 ​V input, which is considered an extreme condition for battery operation.

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The development of a battery-type loader is an important research direction in the field of industrial mining equipment. In the energy system, the battery will inevitably encounter the problem of heat dissipation when using high-power electricity. In this study, we took the power battery pack of a 3 m3 battery-type underground loader as the research object. The influence of single factors, such as the position of the air outlet of the battery pack, the size of the air outlet, the width of the separator, and the reverse plate, on the heat dissipation characteristics of the battery pack were studied. Then, a prediction model between the structural parameters and temperature was established using a radial basis function (RBF) neural network. This prediction model was then used as an adaptation evaluation model for global optimization through the multiobjective particle swarm optimization (PSO) algorithm, using which the optimal combination of structural parameters was obtained. The maximum temperature of the battery pack after optimization was reduced by 22%, compared to that before optimization, and the average temperature was reduced by 12.5%. Overall, the heat dissipation effect significantly improved. The optimization results indicate that the method proposed in this paper is feasible for use in optimizing battery heat dissipation systems in electric vehicles, thus providing a reference for research related to battery pack heat dissipation.

The quality of horticultural products can be promoted using high techniques. One of these methods is precooling applied before storage and leads to increased shelf and storage life of the fruit. For this reason, the effect of forced air cooling was conducted to investigate the cooling rate at the center (aril), spongy tissue (peel) and leathery skin (rind) of pomegranate (Punica granatum L.). Airflow velocity as an effective factor in cooling products at three levels of 0.5, 1, and 1.3 m s-1 and temperature of 7.2 °C was considered. Cooling parameters including lag factor and cooling coefficient were calculated from experimental data. Then, half-cooling time and seven-eighths cooling time were obtained at different layers of pomegranate. Cooling heterogeneity was analyzed at different air velocity and at different layers of pomegranate. The results showed that increase in air velocity from 0.5 to 1.3 m s-1, reduced the half-cooling time and seven-eighths cooling time. After 5000 seconds, the change of air velocity had a slight influence on decreasing temperature of different layers of pomegranate. Cooling heterogeneity at the air velocity of 0.5 m s-1 was low and then increased at the air velocity of 1 m s-1. Finally, at the air velocity of 1.3 m s-1, it was declined. The overall results illustrate that the applied methodology in this research, which explains unsteady heat transfer in the cooling process, can be performed in pomegranate or similarly shaped fruits.

To develop a thermal model for air-cooled plate–fin heatsink and evaluate its thermal performance, empirical equations are available to rapidly calculate the pressure drop and heat transfer coefficients for the fins. Besides the heat transfer coefficients, the local air temperature also affects the heat transfer of the fins, which rises along the channel by absorbing the released heat from the fins. In this article, a heatsink model to account for the air temperature rise is proposed, and a thermal circuit model is used to correlate the increased air temperature and the absorbed heat at the fin boundary. With this convective boundary, the temperature distribution for the base plate of the heatsink is calculated by adopting finite-difference method (FDM), which analyzes the conductive heat transfer for the base plate. Both of them have been programed in MATLAB software, and the calculated temperature by the proposed models is compared with the computational fluid dynamics (CFD) simulation. A fan-cooled plate–fin heatsink for a half-bridge power electronics inverter is tested in the laboratory as an example, and the thermal results obtained from the proposed models are within 10% of error with respect to the CFD simulation results and experimental results. The proposed method is also faster than the CFD simulation. The proposed accurate and rapid thermal modeling method will be essential for virtual prototyping and layout/geometry optimization of power electronics systems. [ABSTRACT FROM AUTHOR]

Due to the merit of very‐short end turns, Gramme‐ring windings are widely used in high‐speed permanent‐magnet motors (HSPMMs). This study investigated the thermal issues of a 300 kW, 12,000 rpm Gramme‐ring‐winding HPSMM with housing water jacket and forced air cooling, based on the computational fluid dynamics (CFD) and numerical heat‐transfer calculations. The reasons that cause the overheat of the prototype in the experimental test are thoroughly analysed. The high wind resistance of air gap as the ventilation duct and the large interface gap between the stator lamination and housing water jacket is thought to be the main reasons. Then improvement of the ventilation structures is studied to decrease the wind resistance. Besides, the modification of water channels is also investigated to avoid the influence of a large interface gap on the water cooling performance. Finally, a new cooling structure, combining the slot ventilation ducts and inside water channels, is proposed for the HSPMM with Gramme‐ring windings. With the new cooling structure, the temperature rise of the motor is decreased, and the power density can be increased. [ABSTRACT FROM AUTHOR]

Summary: Keeping temperature under control is critical for batteries to work effectively. When the safe operating range is exceeded, both the lifetime of batteries decreases and undesirable situations may occur such as fire. In this study, the effects of basbars on battery modules are examined. It is shown that the most intense current transitions pass through the shortest path connecting the batteries. When the distance between the batteries is increased, cooling is effective and the temperature of the batteries is expected to decrease. However, this is not the case in our study. It is observed that the temperature of the battery modules increases due to the increased length of the basbar. For this reason, it is emphasized that basbars are a parameter that cannot be ignored with respect to the temperature of battery modules. In this study, six different materials (ie, silver, copper, gold, nickel, steel and titanium) are used as basbars when trying to achieve the best results. For each basbar material, the maximum temperature values and discharge curves reached by the battery module are found. The results suggest that silver is the best basbar material. For the silver material, the temperature distributions of the battery modules, the maximum temperature value received by the module and the discharge curves are found for different C ratios. [ABSTRACT FROM AUTHOR]

A mathematical model to research airflow distributions and heat transmission in two different packages was developed. The precooling characteristics of two packaging designs were evaluated in terms of cooling time, uniformity, apple quality and energy consumption undergoing forced air cooling. The numerical model was verified by a detailed comparison of predicted and measured results. The modelling results revealed heterogeneous cooling airflow patterns in current ventilated carton, which results in the heterogeneity of product temperature. While in new package design, especially at first layer, the seven eighths cooling time (SECT) was about three times less than the current package, and the mass loss rate was reduced by 66.4 %. In addition, the chilling injury rate and maximum temperature deviation for both apple layers were decreased to 17 % and ~2.7 °C, respectively. The value of energy consumption (EC) was reduced by 65.1 %. [ABSTRACT FROM AUTHOR]

Friction stir welding (FSW) is a promising welding method for welding dissimilar materials without using welding flux. In the present work, 5A06-H112 and 6061-T651 aluminium alloys were successfully welded by friction stir welding with forced air cooling (FAC) and natural cooling (NC). Nanoindentation tests and microstructure characterisations revealed that forced air cooling, which can accelerate the cooling process and suppress the coarsening of grains and the dissolution of precipitate phases, contributes to strengthening and narrowing the weakest area of the joint. The tensile strength of joints with FAC were commonly improved by 10% compared to those with NC. Scanning electron microscopy (SEM) images of the fracture surface elucidated that FSW with FAC tended to increase the number and reduce the size of the dimples. These results demonstrated the advantages of FSW with FAC in welding heat-sensitive materials and provide fresh insight into welding industries.

The quality of horticultural products can be promoted using high techniques. One of these methods is precooling applied before storage and leads to increased shelf and storage life of the fruit. For this reason, the effect of forced air cooling was conducted to investigate the cooling rate at the center (aril), spongy tissue (peel) and leathery skin (rind) of pomegranate (Punica granatum L.). Airflow velocity as an effective factor in cooling products at three levels of 0.5, 1, and 1.3 m s-1 and temperature of 7.2 °C was considered. Cooling parameters including lag factor and cooling coefficient were calculated from experimental data. Then, half-cooling time and seven-eighths cooling time were obtained at different layers of pomegranate. Cooling heterogeneity was analyzed at different air velocity and at different layers of pomegranate. The results showed that increase in air velocity from 0.5 to 1.3 m s-1, reduced the half-cooling time and seven-eighths cooling time. After 5000 seconds, the change of air velocity had a slight influence on decreasing temperature of different layers of pomegranate. Cooling heterogeneity at the air velocity of 0.5 m s-1 was low and then increased at the air velocity of 1 m s-1. Finally, at the air velocity of 1.3 m s-1, it was declined. The overall results illustrate that the applied methodology in this research, which explains unsteady heat transfer in the cooling process, can be performed in pomegranate or similarly shaped fruits. [ABSTRACT FROM AUTHOR]

A battery pack is the main energy storage element, and directly affects the performance of an electric vehicle. Battery thermal management system research and its development for a modern electric vehicle is required. This paper selects the forced air cooling of battery pack as the research object, and uses simulation methods to research the heat dissipation performance with different structures of battery packs. The results indicate that according to the four types of transient state conditions, the rising temperature of both battery packs are significantly higher than the temperature difference, the maximum temperature rise and temperature difference of a horizontal battery pack are lower than a longitudinal battery pack. When an electric vehicle begins to decrease speed, the curves of temperature rising and temperature difference increase. This shows the internal heat is continuously rising, so even in a electric vehicle beginning to decrease speed, the fan must work. The reference basis for choosing battery pack type and an analysis of heat flow field characteristics, including fan run-time control, are offered. [ABSTRACT FROM AUTHOR]

3D stacked die structure is a promising architecture to realize small feature size and enhance electronic performance. However, thermal performance in 3D stacked die has aroused extensive attention for its high density integration. In this paper, a stacked dummy die structure integrated with polyimide heater inside is presented to investigate the thermal behavior of 3D stacked dies. One-dimensional thermal resistance network is built and calculated to analyze thermal resistance distribution of the stacked dies. Under natural convection, the thermal resistance of convective heat transfer greatly influences total thermal resistance and limits heat dissipation ability of stacked dies. To significantly reduce the thermal resistance of convective heat transfer, forced air cooling and water immersion cooling have been applied in the stacked die structure. Experiment and numerical simulation have been conducted in this work. In the experiment, forced air cooling and water immersion cooling systems are set up to cool down the stacked die structure. The temperature dependence of the stacked die structure is obtained by thermocouples. The measured thermal resistances between junction and ambient environment of the stacked die structure decrease to 7.6 °C/W under forced air cooling and to 0.6 °C/W under water immersion cooling, respectively. Then heat dissipation abilities of forced convection cooling for the stacked die structure are analyzed. Simulation models are built for experimental validation and further thermal analysis. Temperature influences on the internal structure of the stacked dies with different power map are discussed. The simulation results can well capture the experimental results with 5.8% variation under forced air cooling and with 7.4% variation under water immersion cooling when total power of 3 W is applied. [ABSTRACT FROM AUTHOR]

Copyright of Problems of Friction & Wear is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Computational fluid dynamics (CFD) model was developed, validated and used to analyse cooling characteristics of two different package designs (CT1 and CT2) used for postharvest handling of pomegranate fruit. The model incorporated geometries of fruits, packaging box, tray and plastic liner. Thin layer of plastic material with conservative interface heat flux was used to model liners. The accuracy of the model to predict airflow and temperature distributions were validated against experimental data. The model predicted airflow through the stacks and cooling rates within experimental error. Stack design markedly affected the airflow profile, rate and uniformity of cooling. The cooling rate of the two package designs differed by 30% and plastic lining increased the average 7/8th cooling times from 4.0 and 2.5 h to 9.5 and 8.0 h for the CT1 and CT2 stacks, respectively. Profile of high and low temperature regions depended considerably on packaging box design. [ABSTRACT FROM AUTHOR]

The fastest kinetics of lamellar disintegration (predicted duration of 44 min) in AISI 1080 steel is obtained with a novel approach of incomplete austenitisation-based cyclic heat treatment involving forced air cooling with an air flow rate of 8.7 m3 h−1. A physical model for process kinetics is proposed that involves lamellar fragmentation, lamellar thickening, divorced eutectoid growth and generation of new lamellar faults in remaining cementite lamellae in each cycle. Lamellar fragmentation is accentuated with faster rate of cooling through generation of more intense lamellar faults; but divorced eutectoid growth is ceased. Accordingly, as compared to still air cooling, much faster kinetics of lamellar disintegration is obtained by forced air cooling together with the generation of much smaller submicroscopic cementite particles (containing more proportion of plate-shaped non-spheroids) in divorced eutectoid region. [ABSTRACT FROM PUBLISHER]

Advantages and disadvantages of heat-dissipating method of electrical equipments for open-pit shearer were analyzed. According to actual condition of open-pit shearer, filter cartridge deduster was used to ventilate and dissipate heat for frequency-conversion speed-regulation device and step-down transforms of open-pit shearer, and the original dedusting ventilation equipment was used to ventilate and heat operating room. The application of filter cartridge deduster and ventilation equipment in the open-pit shearer, not only ensures reliable operation of open-pit shearer and prolongs service life of components of electrical equipment, but also make heat distributed by electrical equipment recycle and reuse and achieve effect of energy saving.

Forced-air cooling (FAC) efficiency of fruit packed in ventilated cartons can be considerably improved by revising vent hole design and tailoring these openings according to the internal packaging used. Current vent hole designs for fruit cartons, however, often result from trials and errors or are developed in order to improve a specific package functionality, such as fruit cooling rate. This study presents a novel multiparameter evaluation process for ventilated fruit packaging. This multi-parameter strategy evaluates cooling rate and cooling uniformity, airflow resistance and energy efficiency. Computational fluid dynamics is used to evaluate the impact of internal trays and four vent hole designs. One of the designs investigated is currently used in commercial export of apples, while the other three are new configurations proposed to improve fruit cooling efficiency. Results showed that the addition of trays to the existing commercially used Standard Vent hole design increased ventilation energy consumption by 31 % compared to cartons without trays, but in the two newly proposed carton designs (Altvent and Multivent), the energy usage was reduced by 27 and 26 %, respectively, as airflow was distributed more evenly between the five fruit layers. The use of the new vent hole designs (Altvent and Multivent) compared to the Standard Vent design, also considerably improved cooling uniformity and energy efficiency during FAC, reducing cooling heterogeneity by 79 and 51 %, as well as energy consumption by 48 and 7 %, when packed with and without trays, respectively. By simultaneous evaluation of multiple parameters, this analysis approach thus unveiled the benefits and disadvantages of the new ventilated carton designs and can be used to further improve vent hole designs for specific cold chains. [ABSTRACT FROM AUTHOR]

Copyright of Problems of Friction & Wear is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper proposes a new design of shape memory alloy (SMA) wire actuated gripper for open mode operation. SMA can generate smooth muscle movements during actuation which make them potentially good contenders in designing grippers. The principle of the shape memory alloy gripper is to convert the linear displacement of the SMA wire actuator into the angular displacement of the gripping jaw. Steady state analysis is performed to design the wire diameter of the bias spring for a known SMA wire. The gripper is designed to open about an angle of 22.5° when actuated using pulsating electric current from a constant current source. The safe operating power range of the gripper is determined and verified theoretically. Experimental evaluation for the uncontrolled gripper showed a rotation of 19.97°. Forced cooling techniques were employed to speed up the cooling process. The gripper is simple and robust in design (single movable jaw), easy to fabricate, low cost, and exhibits wide handling capabilities like longer object handling time and handling wide sizes of objects with minimum utilization of power since power is required only to grasp and release operations. [ABSTRACT FROM AUTHOR]

The finned channel is used as a simplified model for the analysis of thermal conditions of cartridge design electronic equipment with a high power density for forced air cooling. The finned channel thermal model and method of its creating are described by the computer-aided engineering systems. Clearance limitations of the radio electronic units and the manufacturing limitations on width of fins and their numbers are considered during creating the thermal model. The finned channel thermal characteristics that include the thermal resistance dependence on parameters of fins (width, length, number) are investigated. The approximating functions for these dependencies are proposed. To minimize the thermal resistance the correlations for finned channel having the optimal sizes are obtained. The iteration optimization algorithm is developed. This approach provides high accuracy. In the algorithm the thermal conditions are calculated by the computer- aided engineering systems. The example of designing the finned channel with optimal thermal conditions is showed. As a result of optimizing the finned channel thermal resistance decreased by 35 %. [ABSTRACT FROM AUTHOR]