scholarly journals Study of the Application Characteristics of Photovoltaic-Thermoelectric Radiant Windows

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6645
Author(s):  
Wenjie Zhang ◽  
Jiajun Zhang ◽  
Fengcheng Huang ◽  
Yuqiang Zhao ◽  
Yongheng Zhong
Keyword(s):  
Power Generation ◽  
Power Consumption ◽  
Thermoelectric Module ◽  
Operation Time ◽  
Cooling Capacity ◽  
Calculation Model ◽  
Photovoltaic Module ◽  
Photovoltaic Panel ◽  
Calculation Results ◽  
The Relationship

Through experiments and numerical simulation, this paper studies the related performance of a photovoltaic thermoelectric radiation cooling window structure, verifies the accuracy of the established solar thermoelectric radiation window calculation model, and analyzes the cooling performance of different parameters of thermoelectric sheet, radiation plate, and photovoltaic panel. On the basis of considering the relationship between the power generation and power consumption of the structure, the numerical calculation results show that the solar thermoelectric radiation window with non-transparent photovoltaic module (NTPV) has a total cooling capacity of 50.2 kWh, power consumption of 71.8 kWh, and power generation of 83.9 kWh from June to August. The solar thermoelectric radiation window with translucent photovoltaic module (STPV) has a total cooling capacity of 50.7 kWh, power consumption of 71.7 kWh, and power generation of 45.4 kWh from June to August. If the operation time of the thermoelectric module is limited, when the daily operation time of TEM is less than 8 h, the power generation of STPV can meet the power consumption demand of the thermoelectric radiation window from June to August.

Efficiency of Worm Gear Drives Under Transient Operating Conditions

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Manuel Oehler ◽  
Bernd Sauer ◽  
Balázs Magyar
Keyword(s):  
Power Dissipation ◽  
Calculation Model ◽  
Operating Conditions ◽  
Power Losses ◽  
Transient Conditions ◽  
Calculation Results ◽  
Worm Gears ◽  
Gear Drives ◽  
The Relationship ◽  
Over Time

Abstract In oil-lubricated worm gears, all moving components cause power losses during operation. These losses depend, among other things, on the viscosity of the lubricant used, which in turn is determined by the temperature present in the gearbox. The dependency between the temperature and the power dissipation is mutual, and they influence each other. For the analysis of gearboxes under transient conditions, the relationship among operating conditions, power dissipation, and temperature must be considered. In this paper, a method for the analysis of these interrelationships is presented, which is based on the combination of tribological simulation and thermal networks. With the developed calculation model, the gearbox efficiency and the temperature over time can be estimated for arbitrary load cases. The calculation results are compared with measurements on a real gearbox.

Calculation of Sound Radiation Power at Two Ends of Duct System

2011 ◽  
Vol 295-297 ◽  
pp. 2382-2385
Author(s):  
Tao Feng ◽  
Jing Wang ◽  
Bin Liu ◽  
Xue Wu ◽  
Nan Li
Keyword(s):  
Sound Source ◽  
Radiation Power ◽  
Sound Radiation ◽  
Calculation Model ◽  
Sound Power ◽  
Duct System ◽  
Calculation Results ◽  
Source Characteristic ◽  
Sound Radiation Power ◽  
The Relationship

A method to calculate the radiation sound power from the sound source characteristic of the duct component is developed here; The relationship between the sound source characteristic and the acoustical boundary conditions of the duct ends is also researched by the experiment. Based on the two-port model, the sound source characteristic and the sound transfer matrix of the duct component can be obtained by the numerical or experimental methods. The calculation model to predict the radiation sound power at the end of the duct system is deduced from the sound source characteristic of the duct component. A simple experimental duct system to validate the calculation model is setup and the measurement and calculation results are compared here as well.

Analysis of Characteristics of Halogen and LED Automobile Lamps

2020 ◽  
pp. 57-62
Author(s):  
Olga Yu. Kovalenko ◽  
Yulia A. Zhuravlyova
Keyword(s):  
Power Consumption ◽  
Flip Chip ◽  
Weather Conditions ◽  
Luminous Flux ◽  
Luminous Efficacy ◽  
Colour Temperature ◽  
Study Results ◽  
Calculation Results ◽  
Mandatory Rules ◽  
Halogen Lamps

This work contains analysis of characteristics of automobile lamps by Philips, KOITO, ETI flip chip LEDs, Osram, General Electric (GE), Gtinthebox, OSLAMPledbulbs with H1, H4, H7, H11 caps: luminous flux, luminous efficacy, correlated colour temperature. Characteristics of the studied samples are analysed before the operation of the lamps. The analysis of the calculation results allows us to make a conclusion that the values of correlated colour temperature of halogen lamps are close to the parameters declared by manufacturers. The analysis of the study results has shown that, based on actual values of correlated colour temperature, it is not advisable to use LED lamps in unfavourable weather conditions (such as rain, fog, snow). The results of the study demonstrate that there is a slight dispersion of actual values of luminous flux of halogen lamps by different manufacturers. Maximum variation between values of luminous flux of different lamps does not exceed 14 %. The analysis of the measurement results has shown that actual values of luminous flux of all halogen lamps comply with the mandatory rules specified in the UN/ECE Regulation No. 37 and luminous flux of LED lamps exceeds maximum allowable value by more than 8 %. Luminous efficacy of LED lamps is higher than that of halogen lamps: more than 82 lm/W and lower power consumption. The results of the measurements have shown that power consumption of a LED automobile lamp is lower than that of similar halogen lamps by 3 times and their luminous efficacy is higher by 5 times.

scholarly journals Evaporator Optimization of Refrigerator Systems Using Quality Analysis

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 555
Author(s):  
Sangkyung Na ◽  
Sanghun Song ◽  
Seunghyuk Lee ◽  
Jehwan Lee ◽  
Hyun Kim ◽  
...  
Keyword(s):  
Power Consumption ◽  
Operating Time ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Quality Analysis ◽  
Lubricating Oil ◽  
Optimal Operating ◽  
Compressor Piston ◽  
Refrigerator Temperature ◽  
Visualization Experiments

In this study, evaporator optimization, via both experimental and simulation methods was conducted. To evaluate the evaporator performance, under the optimal system, the compressor operating time and the effects of oil on the refrigerator system were studied. If the temperature of the refrigerator chamber reaches the setting value, the compressor stops working and it leads to the temperature of the refrigerator chamber slowly increasing, due to the heat transfer to the ambient. When the refrigerator temperature is out of the setting range, the compressor works again, and the refrigerator repeats this process until the end of its life. These on/off period can be controlled through the compressor piston movement. To determine the optimal compressor operating conditions, experiments of monthly power consumption were conducted under various compressor working times and the lowest power consumption conditions was determined when the compressor worked continuously. Lubricating oil, the refrigerator system, using oil, also influenced the system performance. To evaluate the effect of oil, oil eliminated and oil systems were compared based on cooling capacity and power consumption. The cooling capacity of the oil eliminated system was 2.6% higher and the power consumption was 3.6% lower than that of the oil system. After determining the optimal operating conditions of the refrigerator system, visualization experiments and simulations were conducted to decide the optimal evaporator and the conventional evaporator size can be reduced by approximately 2.9%.

scholarly journals A New MPPT Algorithm for Photovoltaic Power Generation under Uniform and Partial Shading Conditions

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 483
Author(s):  
Novie Ayub Windarko ◽  
Muhammad Nizar Habibi ◽  
Bambang Sumantri ◽  
Eka Prasetyono ◽  
Moh. Zaenal Efendi ◽  
...  
Keyword(s):  
Power Generation ◽  
Duty Cycle ◽  
Operating Conditions ◽  
Maximum Power ◽  
Maximum Power Point ◽  
Partial Shading ◽  
Photovoltaic Panel ◽  
Maximum Power Point Tracker ◽  
Photovoltaic Power ◽  
Power Point

During its operation, a photovoltaic system may encounter many practical issues such as receiving uniform or non-uniform irradiance caused mainly by partial shading. Under uniform irradiance a photovoltaic panel has a single maximum power point. Conversely under non-uniform irradiance, a photovoltaic panel has several local maximum power points and a single global maximum power point. To maximize energy production, a maximum power point tracker algorithm is commonly implemented to achieve the maximum power operating point of the photovoltaic panel. However, the performance of the algorithm will depend on operating conditions such as variation in irradiance. Presently, most of existing maximum power point tracker algorithms work only in a single condition: either uniform or non-uniform irradiance. This paper proposes a new maximum power point tracker algorithm for photovoltaic power generation that is designed to work under uniform and partial shading irradiance conditions. Additionally, the proposed maximum power point tracker algorithm aims to provide: (1) a simple math algorithm to reduce computational load, (2) fast tracking by evaluating progress for every single executed duty cycle, (3) without random steps to prevent jumping duty cycle, and (4) smooth variable steps to increase accuracy. The performances of the proposed algorithm are evaluated by three conditions of uniform and partial shading irradiance where a targeted maximum power point is located: (1) far from, (2) near, and (3) laid between initial positions of particles. The simulation shows that the proposed algorithm successfully tracks the maximum power point by resulting in similar power values in those three conditions. The proposed algorithm could handle the partial shading condition by avoiding the local maxima power point and finding the global maxima power point. Comparisons of the proposed algorithm and other well-known algorithms such as differential evolution, firefly, particle swarm optimization, and grey wolf optimization are provided to show the superiority of the proposed algorithm. The results show the proposed algorithm has better performance by providing faster tracking, faster settling time, higher accuracy, minimum oscillation and jumping duty cycle, and higher energy harvesting.

scholarly journals Influence of Selected Model Parameters on the Electromagnetic Levitation Melting Efficiency

2021 ◽  
Vol 11 (9) ◽  
pp. 3827
Author(s):  
Blazej Nycz ◽  
Lukasz Malinski ◽  
Roman Przylucki
Keyword(s):  
Electromagnetic Levitation ◽  
Optimization Methods ◽  
Calculation Model ◽  
Model Parameters ◽  
Starting Point ◽  
Low Efficiency ◽  
The Relationship ◽  
Reactive Metals ◽  
Electromagnetic Levitation Melting ◽  
Metal Melting

The article presents the results of multivariate calculations for the levitation metal melting system. The research had two main goals. The first goal of the multivariate calculations was to find the relationship between the basic electrical and geometric parameters of the selected calculation model and the maximum electromagnetic buoyancy force and the maximum power dissipated in the charge. The second goal was to find quasi-optimal conditions for levitation. The choice of the model with the highest melting efficiency is very important because electromagnetic levitation is essentially a low-efficiency process. Despite the low efficiency of this method, it is worth dealing with it because is one of the few methods that allow melting and obtaining alloys of refractory reactive metals. The research was limited to the analysis of the electromagnetic field modeled three-dimensionally. From among of 245 variants considered in the article, the most promising one was selected characterized by the highest efficiency. This variant will be a starting point for further work with the use of optimization methods.

scholarly journals Relationship between Oral Bacterial Count and Postoperative Complications among Patients with Cardiovascular Disease Treated by Surgery: A Retrospective Cohort Study

Healthcare ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 850
Author(s):  
Rie Osako ◽  
Yuhei Matsuda ◽  
Chieko Itohara ◽  
Yuka Sukegawa-Takahashi ◽  
Shintaro Sukegawa ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Postoperative Complications ◽  
Operation Time ◽  
Bacterial Count ◽  
Cardiovascular Complications ◽  
Pericardial Fluid ◽  
Bacterial Counts ◽  
Lung Torsion ◽  
Propensity Score Adjustment ◽  
The Relationship

In this retrospective observational study, we evaluated the relationship between perioperative oral bacterial counts and postoperative complications in cardiovascular disease (CVD) patients. From April 2012 to December 2018, all patients scheduled for surgery received perioperative oral management (POM) by oral specialists at a single center. Tongue dorsum bacterial counts were measured on the pre-hospitalization day, preoperatively, and postoperatively. Background data were collected retrospectively. Among the 470 consecutive patients, the postoperative complication incidence rate was 10.4% (pericardial fluid storage, n = 21; postoperative pneumonia, n = 13; surgical site infection, n = 9; mediastinitis, n = 2; and seroma, postoperative infective endocarditis, lung torsion, and pericardial effusion, n = 1 each). Oral bacterial counts were significantly higher in the pre-hospitalization than in the pre- and postoperative samples (p < 0.05). Sex, cerebrovascular disease, and operation time differed significantly between complications and no-complications groups (p < 0.05). Multivariate analysis with propensity score adjustment showed a significant association between postoperative oral bacterial count and postoperative complications (odds ratio 1.26; 95% confidence interval, 1.00–1.60; p = 0.05). Since the development of cardiovascular complications is a multifactorial process, the present study cannot show that POM reduces complications but indicates POM may prevent complications in CVD patients.

Application of the Burnable Poison in the Design of Space Nuclear Reactor

2017 ◽  
Author(s):  
Wang SanBing ◽  
Xie Qilin ◽  
He ChaoHui
Keyword(s):  
Neutron Spectrum ◽  
Nuclear Reactor ◽  
Operation Time ◽  
Life Time ◽  
Stable Operation ◽  
Burnable Poison ◽  
Calculation Results ◽  
Homogeneous Reactor ◽  
In The Beginning ◽  
Criticality Safety

The previous research showed that the application of burnable poison was helpful to improve the criticality safety of space nuclear reactor (SNR). In order to analyze the worth of burnable poison in the SNR’s design, a model of homogeneous reactor had firstly been built based on the design of SAFE400. Comparing its difference with the real design of SAFE400 through criticality calculation, the precise of our model had been verified. Then the influence of the criticality parameters and immersion accident character parameters for this model had been analyzed for the application of the different burnable poisons (such as samarium, europium or gadolinium). The calculation results had shown that the application of the most of the burnable poisons would soften the neutron spectrum and induced a decrement of reactor’s keff in the beginning of life. However, the immersion accident analysis gave out another result that only the reactor using gadolinium could ensure the criticality safety of reactor after it made its initial keff equal with the design value. Meanwhile, compared with the initial design of SAFE400, in one hand, the burn-up results had shown that the decrement of homogeneous reactor’s reactivity using gadolinium as burnable poison was deceased after the 10 years full power operation; in other hand, its neutron spectrum became more softer with the operation time; and what’s more important, the amount of the burnable poison was not decreased with burn-up during its service life-time. These results implied that the application of the burnable poison (especially for gadolinium) could highly ensure the criticality safety and stable operation of SNR.

scholarly journals Mathematical model for the power generation from arbitrarily oriented photovoltaic panel

2017 ◽  
Vol 14 ◽  
pp. 01028 ◽  
Author(s):  
Qusay Hassan ◽  
Marek Jaszczur ◽  
Estera Przenzak
Keyword(s):  
Mathematical Model ◽  
Power Generation ◽  
Photovoltaic Panel
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