scholarly journals Study of Temperature Profile of the Solar Pyramid Dryer

2021 ◽  
Vol 10 (10) ◽  
pp. 252-258
Author(s):  
O. S. Karpe A. G. Mohod ◽  
Y. P. Khandetod R. T. Thokal ◽  
R. M. Dharaskar
Keyword(s):  
Temperature Profile ◽  
Fruits And Vegetables ◽  
Maximum Temperature ◽  
Energy Sources ◽  
Temperature Pattern ◽  
Drying Temperature ◽  
Solar Dryer ◽  
Bottom To Top

The experiment was conducted at ‘Energy Park’, Department of Electrical and Other Energy Sources CAET, Dr. Balasaheb Sawant Konkan Krushi vidyapeeth Dapoli, Dapoli. The readings of temperature inside the dryer has been taken from 9:00 AM TO 5:00 PM with interval of thirty minute. It is recorded that maximum temperature inside the solar pyramid dryer was at 12:00 noon that is 55.5 0C and corresponding solar radiations where 552 W/m2.After analysing the temperature pattern from the graphs we can say that the temperature of air inside the dryer at various places varies such that, temperature of air at bottom of dryer was minimum, and it goes on increasing as the air moves from bottom to top of the solar pyramid dryer. Subsequently the maximum temperature found at the exhaust of the solar dryer. The average drying temperature is found to be suitable for drying of fruits and vegetables.

scholarly journals Performance Enhancement of Natural Convection Indirect Solar Dryer by Integrating Reflectors

2021 ◽  
Vol 12 (2) ◽  
pp. 212-222
Author(s):  
Hailay Teklu ◽  
Mulu Bayray ◽  
Dawit Abay ◽  
Millerjothi Kalamegam
Keyword(s):  
Natural Convection ◽  
Fruits And Vegetables ◽  
Performance Enhancement ◽  
Load Test ◽  
Maximum Temperature ◽  
Stagnation Temperature ◽  
Solar Dryer ◽  
Moisture Balance ◽  
Similar Temperature ◽  
Drying Efficiency

Natural convection indirect type solar dryer integrated with reflectors that can be used for drying fruits and vegetables was designed, constructed, and evaluated. The study mainly tried to improve the performance of a prototype natural convection indirect solar dryer. The solar dryer was integrated with reflectors and its thermal performance was experimentally analyzed and results were compared with the same dryer without reflectors. The experiments conducted included a no-load test to determine the stagnation temperature that can be reached and drying tests using tomato slices. During the drying test, moisture content at the initial and final stages was measured using a moisture balance instrument. The mass of the tomato slices was measured every two hours to find the drying efficiency. Temperatures were measured using thermocouples located at the absorber plate and at the trays inside the drying cabinet. Solar radiation was also measured using a pyranometer located near the dryer. During no load experiments, the maximum temperature reached the collector was around 98oC for the dryer without reflectors. The maximum temperature was improved to around 154oC during the test with reflectors. Similar temperature improvement was obtained during the drying tests as well. Due to the improvement in the temperature in the collector, the drying rate was also improved by 8% for 10 kg and 14% for 5 kg load. The experimental results indicate that the dryer performance was improved when the reflectors were added.

A Multi-Dwell Temperature Profile Design for the Cure of Thick CFRP Composite Laminates

2021 ◽  
Author(s):  
Wenchang Zhang ◽  
Yingjie Xu ◽  
Xinyu Hui ◽  
Weihong Zhang
Keyword(s):  
Temperature Profile ◽  
Composite Laminates ◽  
Optimization Method ◽  
Maximum Temperature ◽  
Nsga Ii ◽  
Multi Objective ◽  
Optimization Result ◽  
Design Variables ◽  
Cure Time ◽  
Thick Laminates

Abstract This paper develops a multi-objective optimization method for the cure of thick composite laminates. The purpose is to minimize the cure time and maximum temperature overshoot in the cure process by designing the cure temperature profile. This method combines the finite element based thermo-chemical coupled cure simulation with the non-dominated sorting genetic algorithm-II (NSGA-II). In order to investigate the influence of the number of dwells on the optimization result, four-dwell and two-dwell temperature profiles are selected for the design variables. The optimization method obtains successfully the Pareto optimal front of the multi-objective problem in thick and ultra-thick laminates. The result shows that the cure time and maximum temperature overshoot are both reduced significantly. The optimization result further illustrates that the four-dwell cure profile is more e ective than the two-dwell, especially for the ultra-thick laminates. Through the optimization of the four-dwell profile, the cure time is reduced by 51.0% (thick case) and 30.3% (ultra-thick case) and the maximum temperature overshoot is reduced by 66.9% (thick case) and 73.1% (ultra-thick case) compared with the recommended cure profile. In addition, Self-organizing map (SOM) is employed to visualize the relationships between the design variables with respect to the optimization result.

scholarly journals Investigation on the effect of electrode tip on formation of metal droplets and temperature profile in a vibrating electrode electroslag remelting process

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 743-751 ◽  
Author(s):  
Fang Wang ◽  
Jakov Baleta ◽  
Qiang Wang ◽  
Baokuan Li
Keyword(s):  
Temperature Profile ◽  
Electroslag Remelting ◽  
Temperature Fields ◽  
Maximum Temperature ◽  
Periodic Pattern ◽  
Coupled Modelling ◽  
Frequency Changes ◽  
Volume Method ◽  
Peak Value ◽  
Metal Droplets

Abstract In the present work, a transient full-coupled modelling approach has been put forward to study the effect of electrode tip on formation of metal droplets and temperature profile in the electromagnetically-controlled electroslag-remelting furnace with vibrating electrode. The electromagnetic field, momentum and energy conservation equations are solved simultaneously based on the finite volume method. The interface of slag and metal is traced using the volume of fluid approach. The results show that in the case of cone tip electrode the average dimension of metal droplets is smaller compared to the flat tip electrode. In addition, the bigger and stretched metal droplets are not observed with the cone tip electrode. The temperature fields with the cone tip electrode are distributed in a prominent periodic pattern compared to the case with flat tip electrode. The maximum temperature zone with the cone tip electrode is located along the z axial in the upper part of slag, not in the lower part. When the frequency changes from 0.17 Hz to 1 Hz, the maximum temperature reduces from 2050 K to 1985 K and the peak value of velocity decreases from 0.20 m/s to 0.125 m/s. When the vibration amplitude varies from 3mm to 6mm, the maximum temperature in the slag cover drops by 3.9% and the peak value of velocity rises by 16.7%.

Optimization of diesel substitution rate based on piston maximum temperature pattern recognition in dual-fuel engine

2016 ◽  
Vol 231 (10) ◽  
pp. 1388-1401 ◽  
Author(s):  
Youyao Fu ◽  
Bing Xiao
Keyword(s):  
Pattern Recognition ◽  
Substitution Rate ◽  
Closed Loop ◽  
Maximum Temperature ◽  
Support Vector ◽  
Dual Fuel ◽  
Temperature Pattern ◽  
Closed Loop Control ◽  
Loop Control ◽  
Penalty Factor

The diesel and natural gas dual-fuel engine has gained increasing interest in recent years because of its excellent power and economy. However, the diesel substitution rate cannot be controlled optimally, owing to the lack of a feedback indicator reflecting the cylinder combustion process, which easily leads to a serious thermal load problem. This paper presents a closed-loop control with feedback from a piston maximum temperature (PMT) pattern to regulate the diesel substitution rate in real time. A v-support vector machine ( v-SVM) is proposed to train classifiers for online recognition of the PMT pattern. Nitrogen oxide (NOx) emission levels, excess air coefficient, engine speed and inlet pressure are chosen as feature variables. The PMTs, calculated by finite element analysis in ANSYS, are utilized to determine the labels of feature data. Moreover, 10-fold cross-validation is employed to choose the optimal kernel function, kernel parameters and penalty factor. A synthetic minority oversampling technique (SMOTE) is introduced to remedy the class imbalance problem in training classifiers. Furthermore, a timer-based debouncing mechanism is employed to alleviate the dynamic process influence on the PMT pattern recognition. Experiment revealed that the classifiers yield desirable predictions, with classification accuracies higher than 90%. Meanwhile, the diesel substitution rates are regulated to appropriate values through the closed-loop control algorithm, which guarantees that the dual-fuel engine runs in its safe region and maintains its excellent economy.

Applying CFD for Studying the Dynamic and Thermal Behavior of Solar Chimney Drying System with Reversed Absorber

2017 ◽  
Vol 13 (11) ◽  
Author(s):  
Souheyla Khaldi ◽  
A. Nabil Korti ◽  
Said Abboudi
Keyword(s):  
Thermal Behavior ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Numerical Study ◽  
Packed Bed ◽  
Maximum Temperature ◽  
Storage Material ◽  
Solar Chimney ◽  
Solar Dryer

AbstractThis article provides numerical study of the solar chimney (SC) assembled with a reversed absorber and packed bed for the indirect-mode solar dryer. The present study was designed to determine the effects of using the SC in three configuration and physical proprieties of the packed (thickness and porosity) on the dynamic and thermal behavior of airflow. The results reveal that (1) using SC without storage material can increase the maximum mass flow rate up to 5%. However, integrating a storage material in the SC can improve the mass flow rate up to 32% during nighttime; (2) the use of a packed bed can decrease the crops temperature fluctuation until about 76% and increase the operating time of the solar dryer up to 12.5 hours rather than 10 hours in the case without packed bed; (3) increasing the porosity from 0.1 to 0.8 can increase the maximum temperature by about 10°C.

Characteristic of Low Calorific Fuel Gas Combustion in a Pressurized Porous Burner

2014 ◽  
Vol 1070-1072 ◽  
pp. 1713-1717
Author(s):  
Guan Qing Wang ◽  
Dan Luo ◽  
Ning Ding ◽  
Jiang Rong Xu
Keyword(s):  
Flame Front ◽  
Temperature Profile ◽  
Axial Direction ◽  
Normal Pressure ◽  
Maximum Temperature ◽  
Combustion Characteristic ◽  
Gas Combustion ◽  
Fuel Gas ◽  
Flame Propagation Velocity ◽  
Porous Burner

Combustion characteristic of low calorific fuel gas in a pressurized porous burner was numerically investigated. The two-dimensional temperature profile, flame front, and CO concentration distribution were analyzed under the pressure at the certain operating parameters, and compared with those of the normal pressure. The results shows that the pressured temperature profile is more clear than that of the normal pressure, and maximum temperature distribution region is larger. Compared with the normal pressure, the pressured flame front location is at the downstream, and the flame propagation velocity along with inclination increases with the pressure increasing. The CO distribution is corresponding to the temperature profile. Its maximum locates at the position of the flame front, and gradually decreasing along the axial direction. It decreases with the pressure increasing, which indicates that the pressure contributes to improve the combustion efficiency.

Design, Analysis and Experimental Evaluation of Photovoltaic Forced Convection Solar Dryer for the Tropics

2010 ◽  
Vol 3 ◽  
pp. 49-61 ◽  
Author(s):  
A.O. Adelaja ◽  
S.J. Ojolo
Keyword(s):  
Forced Convection ◽  
Solar Irradiation ◽  
Maximum Temperature ◽  
Experimental Investigations ◽  
Drying Time ◽  
Solar Dryer ◽  
Sunshine Hours ◽  
Useful Power ◽  
Collector Efficiency ◽  
The Tropics

The photovoltaic (pv) forced convection solar dryer comprises the solar collector, dryer and pv assemblies. It is designed for a continuous operation throughout the day. The direct solar irradiation is utilized during sunshine hours and it automatically switches power supply to the battery during cloud covers and non-insolation periods. The inclusion of a heat reservoir enables heat transfer to continue during this period. In this study, thermal and dryer analyses were done. Experimental investigations were carried out to evaluate the performance of the system by drying plantain chips. The useful power collected was found to be, 391.50W, collector efficiency, 65.6%, dryer efficiency, 39.6%, average drying rate during insolation, 0.0169kg/hr and total drying time was 23 hours. The maximum temperature attained was 55oC. The average drying non insolation period was 0.0112kg/hr. The capital cost is less than $350.

scholarly journals Temperature profile and residual heat of monopolar laparoscopic and endoscopic dissection instruments

2021 ◽  
Author(s):  
Franz Brinkmann ◽  
Ronny Hüttner ◽  
Philipp J. Mehner ◽  
Konrad Henkel ◽  
Georgi Paschew ◽  
...  
Keyword(s):  
Temperature Profile ◽  
Power Level ◽  
Infrared Camera ◽  
Modern Medicine ◽  
Cooling Time ◽  
Maximum Temperature ◽  
Shaft Length ◽  
Energy Application ◽  
Laparoscopic Tools ◽  
Residual Heat

Abstract Background Endoscopic and laparoscopic electrosurgical devices (ED) are of great importance in modern medicine but can cause adverse events such as tissue injuries and burns from residual heat. While laparoscopic tools are well investigated, detailed insights about the temperature profile of endoscopic knives are lacking. Our aim is to investigate the temperature and the residual heat of laparoscopic and endoscopic monopolar instruments to increase the safety in handling ED. Methods An infrared camera was used to measure the temperature of laparoscopic and endoscopic instruments during energy application and to determine the cooling time to below 50 °C at a porcine stomach. Different power levels and cutting intervals were studied to investigate their impact on the temperature profile. Results During activation, the laparoscopic hook exceeded 120 °C regularly for an up to 10 mm shaft length. With regards to endoknives, only the Dual Tip Knife showed a shaft temperature of above 50 °C. The residual heat of the laparoscopic hook remained above 50 °C for at least 15 s after activation. Endoknives cooled to below 50 °C in 4 s. A higher power level and longer cutting duration significantly increased the shaft temperature and prolonged the cooling time (p < 0.001). Conclusion Residual heat and maximum temperature during energy application depend strongly on the chosen effect and cutting duration. To avoid potential injuries, the user should not touch any tissue with the laparoscopic hook for at least 15 s and with the endoknives for at least 4 s after energy application. As the shaft also heats up to over 120 °C, the user should be careful to avoid tissue contact during activation with the shaft. These results should be strongly considered for safety reasons when handling monopolar ED.

High-Resolution Thermal Profiling of a Combustor in a Non-Dedicated Test Using Thermal History Coatings

2021 ◽  
Author(s):  
David Peral ◽  
Ahmed Zaid ◽  
Christoph Benninghoven ◽  
Silvia Araguas-Rodríguez ◽  
David Kluß ◽  
...  
Keyword(s):  
High Resolution ◽  
Temperature Profile ◽  
Gas Turbine ◽  
Thermal History ◽  
Cooling System ◽  
Maximum Temperature ◽  
Thermal Testing ◽  
Cooling Hole ◽  
Advanced Analysis ◽  
The Impact

Abstract The requirement for reduced emissions and the growing demand on gas turbine efficiency are in part met through increasing firing temperatures. However, development budgets leave only limited time for dedicated thermal testing. Consequently, manufacturers are seeking novel temperature measurement technologies to validate new engine designs. This paper will demonstrate how a new temperature mapping technology can be utilized for non-dedicated (multi-cycling) testing while still delivering high-resolution temperature data in a non-dedicated test on a combustor of an industrial gas turbine. Typically, thermocouples are used to monitor the temperature during tests, but they only provide one data point. Colour changing thermal paints are used to deliver measurements over complete surfaces, but they require dedicated testing with short-duration exposure, necessitating dismantling and re-assembling the engine for further testing. Thermal History Coatings (THC) present an alternative solution to providing high-density temperature information. This coating permanently changes consistent with the maximum temperature of exposure during test. A laser-based instrumentation technique is then used to obtain temperatures. The maximum temperature profile of the surface can be determined through a customized calibration. Given the complex cooling system of a combustor, the high temperatures and the long-time exposure, this case offers a unique possibility for the testing of the coating under real engine conditions. The coated region covered the external surface of the can. Highly significant is the number of measurement points in excess of 7,000 (2 × 2 mm resolution, which enables advanced analysis. This provides insight into the impact of local features, e.g. the region adjacent to a cooling hole. The temperature profile is compared to a CFD-CHT model and thermocouple measurements for the calibration of cooling pre-design methods.

Two-Stage System for Utilization of Renewable Energy Sources with Application of Natural Physical Cavities

2013 ◽  
Vol 649 ◽  
pp. 211-214
Author(s):  
Milan Bielek ◽  
Boris Bielek ◽  
Juraj Híreš ◽  
Jan Szabo
Keyword(s):  
Renewable Energy ◽  
Renewable Energy Sources ◽  
Energy Utilization ◽  
Maximum Temperature ◽  
Energy Sources ◽  
In Situ Experiment ◽  
Two Stage ◽  
Outdoor Climate ◽  
Stage System

Natural physical cavity. Quantification of annual temperature regime of natural physical cavity by in-situ experiment. Annual course of temperature of outdoor climate. Annual course of maximum temperature of natural physical cavity of optimal south-west orientation. Concept of new possibilities for energy utilization of air from natural physical cavities. Two-stage system for utilization of renewable energy sources.

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