scholarly journals Simulation Research on 40t/d Counter-flow Rotary Kiln Incineration System

2021 ◽  
Author(s):  
Shiqiao Yang ◽  
Qingfeng Kong ◽  
Dewang Zeng ◽  
Shiliang Wu ◽  
Feng Gong ◽  
...  
Keyword(s):  
Wind Speed ◽  
Rotary Kiln ◽  
Waste Heat ◽  
Operating Temperature ◽  
Optimal Operation ◽  
Counter Flow ◽  
Simulation Research ◽  
Air Volume ◽  
Pyrolysis Model ◽  
Air Speed

Abstract In this paper, a counter-flow rotary kiln incineration system with a processing capacity of 40 t/d of an environmental protection company in Jiangsu Province was used as the research object, and the mixed pyrolysis model and computational fluid dynamics（CFD）model of the counter-flow rotary kiln incineration system were established using Aspen plus and Fluent software. The influence of the operating temperature of the rotary kiln, the heating value of solid waste, the operating load of the rotary kiln, and the primary air volume and primary air speed on the operating effect of the rotary kiln were explored. Operating temperature, primary air volume and wind speed can all have a greater impact on the incineration performance of the counterflow rotary kiln. When the operating temperature of the counter-flow rotary kiln is greater than 800 o C, the hazardous waste heat value is not less than 1500 kcal/kg, and the primary wind speed is 1.5 m/s, the operating effect of the counter-flow rotary kiln incineration system is the best. The simulation results can provide theoretical guidance for the design and optimal operation of the counterflow rotary kiln incineration system.

scholarly journals An Optimized Flutter-Driven Triboelectric Nanogenerator with a Low Cut-In Wind Speed

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 366
Author(s):  
Yang Xia ◽  
Yun Tian ◽  
Lanbin Zhang ◽  
Zhihao Ma ◽  
Huliang Dai ◽  
...  
Keyword(s):  
Power Generation ◽  
Wind Speed ◽  
Energy Harvesting ◽  
Wind Energy ◽  
Output Power ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Triboelectric Nanogenerator ◽  
Vibration Behavior ◽  
Air Speed

We present an optimized flutter-driven triboelectric nanogenerator (TENG) for wind energy harvesting. The vibration and power generation characteristics of this TENG are investigated in detail, and a low cut-in wind speed of 3.4 m/s is achieved. It is found that the air speed, the thickness and length of the membrane, and the distance between the electrode plates mainly determine the PTFE membrane’s vibration behavior and the performance of TENG. With the optimized value of the thickness and length of the membrane and the distance of the electrode plates, the peak open-circuit voltage and output power of TENG reach 297 V and 0.46 mW at a wind speed of 10 m/s. The energy generated by TENG can directly light up dozens of LEDs and keep a digital watch running continuously by charging a capacitor of 100 μF at a wind speed of 8 m/s.

Evaluation of Energy Efficiency for a CCHP System With Available Microturbine

2007 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang
Keyword(s):  
Gas Turbine ◽  
Waste Heat ◽  
Energy System ◽  
Primary Energy ◽  
Economic Benefits ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Energetic Efficiency ◽  
Efficiency Evaluation

This paper deals with the problem of energy utilization efficiency evaluation of a microturbine system for Combined Cooling, Heating and Power production (CCHP). The CCHP system integrates power generation, cooling and heating, which is a type of total energy system on the basis of energy cascade utilization principle, and has a large potential of energy saving and economical efficiency. A typical CCHP system has several options to fulfill energy requirements of its application, the electrical energy can be produced by a gas turbine, the heat can be generated by the waste heat of a gas turbine, and the cooling load can be satisfied by an absorption chiller driven by the waste heat of a gas turbine. The energy problem of the CCHP system is so large and complex that the existing engineering cannot provide satisfactory solutions. The decisive values for energetic efficiency evaluation of such systems are the primary energy generation cost. In this paper, in order to reveal internal essence of CCHP, we have analyzed typical CCHP systems and compared them with individual systems. The optimal operation of this system is dependent upon load conditions to be satisfied. The results indicate that CCHP brings 38.7 percent decrease in energy consumption comparing with the individual systems. A CCHP system saves fuel resources and has the assurance of economic benefits. Moreover, two basic CCHP models are presented for determining the optimum energy combination for the CCHP system with 100kW microturbine, and the more practical performances of various units are introduced, then Primary Energy Ratio (PER) and exergy efficiency (α) of various types and sizes systems are analyzed. Through exergy comparison performed for two kinds of CCHP systems, we have identified the essential principle for high performance of the CCHP system, and consequently pointed out the promising features for further development.

scholarly journals An analysis of temperature distribution in solar photovoltaic module under various environmental conditions

2018 ◽  
Vol 240 ◽  
pp. 04004 ◽  
Author(s):  
Marek Jaszczur ◽  
Qusay Hassan ◽  
Janusz Teneta ◽  
Ewelina Majewska ◽  
Marcin Zych
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Wind Speed ◽  
Solar Radiation ◽  
Environmental Conditions ◽  
Operating Temperature ◽  
Photovoltaic Module ◽  
Solar Photovoltaic ◽  
System Efficiency ◽  
Pv System

The operating temperature of the photovoltaic module is an important issue because it is directly linked with system efficiency. The objective of this work is to evaluate temperature distribution in the photovoltaic module under different environmental conditions. The results shown that photovoltaic module operating temperature depends not only on the ambient temperature or solar radiation dependent but also depends on wind speed and wind direction. It is presented that the mounting conditions which are not taken into consideration by most of the literature models also play a significant role in heat transfer. Depends on mounting type an increase in module operating temperature in the range 10-15oC was observed which cause further PV system efficiency decrease of about 3.8-6.5 %.

THE INFLUENCE OF WIND SPEED ON THE PV PLANT OPERATING TEMPERATURE: A CASE STUDY FOR FORTALEZA

2021 ◽  
Author(s):  
Eliezer da Silva Holanda Neto ◽  
Leticia de Oliveira Santos ◽  
Carla Freitas de Andrade ◽  
PAULO CARVALHO ◽  
Paulo Alexandre Costa Rocha
Keyword(s):  
Wind Speed ◽  
Operating Temperature

A new low-turbulence wind tunnel for bird flight experiments at Lund University, Sweden

1997 ◽  
Vol 200 (10) ◽  
pp. 1441-1449 ◽  
Author(s):  
C J Pennycuick ◽  
T Alerstam ◽  
A Hedenström
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Test Section ◽  
Safety Net ◽  
Turbulence Level ◽  
Bird Flight ◽  
Contraction Ratio ◽  
Unrestricted Access ◽  
Side Walls ◽  
Air Speed

A new wind tunnel for experiments on bird flight was completed at Lund University, Sweden, in September 1994. It is a closed-circuit design, with a settling section containing five screens and a contraction ratio of 12.25. The test section is octagonal, 1.20 m wide by 1.08 m high. The first 1.2 m of its length is enclosed by acrylic walls, and the last 0.5 m is open, giving unrestricted access. Experiments can be carried out in both the open and closed parts, and comparison between them can potentially be used to measure the lift effect correction. The fan is driven by an a.c. motor with a variable-frequency power supply, allowing the wind speed to be varied continuously from 0 to 38 m s-1. The whole machine can be tilted to give up to 8 ° descent and 6 ° climb. A pitot-static survey in the test section showed that the air speed was within ±1.3 % of the mean at 116 out of 119 sample points, exceeding this deviation at only three points at the edges. A hot-wire anemometer survey showed that the turbulence level in the closed part of the test section was below 0.04 % of the wind speed throughout most of the closed part of the test section, rising to approximately 0.06 % in the middle of the open part. No residual rotation from the fan could be detected in the test section. No decrease in wind speed was detectable beyond 3 cm from the side walls of the closed part, and turbulence was minimal beyond 10 cm from the walls. The installation of a safety net at the entrance to the test section increased the turbulence level by a factor of at least 30, to 1.2 % longitudinally and 1.0 % transversely.

scholarly journals An MPPT Control of a PMSG-Based WECS with Disturbance Compensation and Wind Speed Estimation

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6344
Author(s):  
Janusz Baran ◽  
Andrzej Jąderko
Keyword(s):  
Wind Speed ◽  
Reactive Power ◽  
Nonlinear Function ◽  
Variable Structure ◽  
Synchronous Generator ◽  
Angular Speed ◽  
Voltage Source ◽  
Simulation Research ◽  
Point Tracking ◽  
Power Point

The paper presents simulation research on a variable structure control scheme of a small variable-speed fixed-pitch wind energy conversion system (WECS) with a three-phase permanent magnet synchronous generator (PMSG) in variable wind conditions. The WECS is connected to a power grid through two back-to-back voltage source converters (VSCs) with a DC link. The presented control algorithm is based on feedforward compensation of the wind turbine aerodynamic torque estimated using a linear disturbance observer (DOB). The torque estimate is employed to determine the effective wind speed, required for setting the reference angular speed, using numerical zero search of a nonlinear function. The simulation model, built in the Matlab/Simulink environment using the Simscape Electrical toolbox, includes the field-oriented control of the PMSG via the machine VSC, performed by cascaded angular velocity and current/torque PI controllers, as well as synchronization with the grid and the reactive power control via the grid VSC. The presented results are focused on the performance of the proposed control in the maximum power point tracking (MPPT) operating region of the WECS for various wind speed profiles.

scholarly journals Analysis of the Wind System Operation in the Optimal Energetic Area at Variable Wind Speed over Time

2019 ◽  
Vol 11 (5) ◽  
pp. 1249 ◽  
Author(s):  
Ciprian Sorandaru ◽  
Sorin Musuroi ◽  
Flaviu Frigura-Iliasa ◽  
Doru Vatau ◽  
Marian Dordescu
Keyword(s):  
Wind Speed ◽  
Angular Velocity ◽  
Optimal Operation ◽  
Wind System ◽  
Optimal Velocity ◽  
Electric Generator ◽  
Wind Speeds ◽  
Power Point ◽  
Variable Wind ◽  
Over Time

Due to high mechanical inertia and rapid variations in wind speed over time, at variable wind speeds, the problem of operation in the optimal energetic area becomes complex and in due time it is not always solvable. No work has been found that analyzes the energy-optimal operation of a wind system operating at variable wind speeds over time and that considers the variation of the wind speed over time. In this paper, we take into account the evolution of wind speed over time and its measurement with a low-power turbine, which operates with no load at the mechanical angular velocity ωMAX. The optimal velocity is calculated. The energy that is captured by the wind turbine significantly depends on the mechanical angular velocity. In order to perform a function in the maximum power point (MPP) power point area, the load on the electric generator is changed, and the optimum mechanical velocity is estimated, ωOPTIM, knowing that the ratio ωOPTIM/ωMAX does not depend on the time variation of the wind speed.

Design and Operation of a Hybrid CCHP System Including PV-Wind Devices

2013 ◽  
Author(s):  
J. L. Wang ◽  
J. Y. Wu ◽  
C. Y. Zheng
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Waste Heat ◽  
Internal Combustion ◽  
Energy System ◽  
Optimal Operation ◽  
Combustion Engines ◽  
Wind System ◽  
Fuel Price

CCHP systems based on internal combustion engines have been widely accepted as efficient distributed energy resources systems. CCHP systems can be efficient mainly because that the waste heat of engines can be recovered and used. If the waste heat is not used, CCHP systems may not be beneficial choices. PV-wind systems can generate electricity without fuel consumption, but the electric output depends on the weather, which is not reliable. A PV-wind system can be integrated into a CCHP system to form a higher efficient energy system. Actually, a hybrid energy system based on PV-wind devices and internal combustion engines has been studied by many researchers. But the waste heat of the engine is seldom considered in the previous work. Researches show that, 20∼30% energy can be converted into electricity by a small size engine while more than 70% is released. If the waste heat is not recovered, the system cannot reach a high efficiency. This work aims to analyze a hybrid CCHP system with PV-wind devices. Internal combustion engines are the prime movers whose waste heat is recovered for house heating or driving absorption chillers. PV-wind devices are added to reduce the fuel consumption and total cost. The optimal design method and optimal operation strategy are proposed basing on hourly analyses. Influences of the device cost and fuel price on the optimal dispatch strategies are discussed. Results show that all of the excess energy from the PV-wind system is not worth being stored by the battery. The hybrid CCHP system can be more economical and higher efficient in the studied case.

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