scholarly journals Thermal Characteristics and Parametric Analysis of an Improved Solar Wall

2021 ◽  
Vol 11 (14) ◽  
pp. 6325
Author(s):  
Xi Zhao ◽  
Jiayin Zhu ◽  
Ruixin Li ◽  
Weilin Li ◽  
Bin Chen
Keyword(s):  
Automatic Control ◽  
Thermal Efficiency ◽  
Parametric Analysis ◽  
Thermal Characteristic ◽  
Thermal Characteristics ◽  
Heat Output ◽  
Efficiency Improvement ◽  
Operation Control ◽  
Simulation Results ◽  
Solar Wall

Solar air collectors installed on buildings can significantly reduce conventional energy consumption in winter and summer. However, some problems arise in the utilization process, such as overheating, inconvenient operation control and low energy efficiency, etc. This work is a parametric analysis focusing on the automatic control and thermal efficiency improvement of the solar wall. An improved color-changing solar wall integrated with automatic control components, such as a photoelectric fan and temperature-controlled damper, was proposed in this paper. Based on the experimental data, the average daily heat output of the color-changing solar wall is 1.08 MJ per unit floor area on clear days in winter and the average thermal efficiency is 56.8%. Meanwhile, a quantitative analysis was carried out based on monitoring experiments for evaluating the thermal characteristic of automatic control components. Furthermore, in order to improve the thermal performance of the solar wall, parametric analysis was performed by numerical simulation. Results from this paper can provide a theoretical basis for the application of solar air collectors in modern buildings.

scholarly journals Design and thermal characteristic analysis of motorized spindle cooling system

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110208
Author(s):  
Yuan Zhang ◽  
Lifeng Wang ◽  
Yaodong Zhang ◽  
Yongde Zhang
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Thermal Deformation ◽  
Cooling System ◽  
Thermal Characteristic ◽  
Water Flow Rate ◽  
Thermal Characteristics ◽  
Characteristic Analysis ◽  
Motorized Spindle ◽  
Experiment And Simulation

The thermal deformation of high-speed motorized spindle will affect its reliability, so fully considering its thermal characteristics is the premise of optimal design. In order to study the thermal characteristics of high-speed motorized spindles, a coupled model of thermal-flow-structure was established. Through experiment and simulation, the thermal characteristics of spiral cooling motorized spindle are studied, and the U-shaped cooled motorized spindle is designed and optimized. The simulation results show that when the diameter of the cooling channel is 7 mm, the temperature of the spiral cooling system is lower than that of the U-shaped cooling system, but the radial thermal deformation is greater than that of the U-shaped cooling system. As the increase of the channel diameter of U-shaped cooling system, the temperature and radial thermal deformation decrease. When the diameter is 10 mm, the temperature and radial thermal deformation are lower than the spiral cooling system. And as the flow rate increases, the temperature and radial thermal deformation gradually decrease, which provides a basis for a reasonable choice of water flow rate. The maximum error between experiment and simulation is 2°C, and the error is small, which verifies the accuracy and lays the foundation for future research.

scholarly journals Evaluating the Effect of External Horizontal Fixed Shading Devices’ Geometry on Internal Air Temperature, Daylighting and Energy Demand in Hot Dry Climate. Case Study of Ghardaïa, Algeria

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 348
Author(s):  
Sahar Magri Elouadjeri ◽  
Aicha Boussoualim ◽  
Hassan Ait Haddou
Keyword(s):  
Solar Radiation ◽  
Parametric Analysis ◽  
Energy Demand ◽  
Daylighting Simulation ◽  
Simulation Results ◽  
Shading Devices ◽  
Heating Loads ◽  
Shading Device ◽  
The City

The present study investigates the effect of fixed external shading devices’ geometry on thermal comfort, daylighting and energy demand for cooling and heating in the hot and dry climate of the city of Ghardaïa (Algeria). A parametric analysis was performed by using three software: RADIANCE 2.0 and DAYSIM 3.1 for daylighting simulation and TRNSYS.17 for thermal dynamic simulation. Three shading device parameters were assessed: the spacing between slats, the tilted angle and the slats installation. The vertical shading angle “VSA” is fixed; it is equal to the optimum shading angle measured for Ghardaïa. The simulation results indicate that fixed external shading devices have a significant impact on decreasing the energy demand for cooling; however, they are unable to reduce the total energy demand since they significantly increase heating loads. It was found that fixed external shading devices remove all risks associated with glare in summer by decreasing illuminance close to the window; however, they do not improve daylighting performance in winter because of glare. We note that even if the vertical shading angle “VSA” was the same for all cases, these did not present the same thermal and luminous behavior. This is mainly due to the amount and the way that the solar radiation penetrates space.

scholarly journals Lifetime and Energy Efficiency Improvement Techniques for Hierarchical Networks

2019 ◽  
Vol 9 (1S6) ◽  
pp. 62-72
Keyword(s):  
Cost Effective ◽  
Residual Energy ◽  
Efficiency Improvement ◽  
Hierarchical Networks ◽  
Energy Efficiency Improvement ◽  
Battery Capacity ◽  
Time Scheduling ◽  
Network Operation ◽  
Simulation Results ◽  
Hole Detection

The detection points are the detection points in the space of network. The properties of detection points include cost effective materials and longer battery capacity. WSN can span variety of applications like sensing of data related to environment entities, detection of enemy vehicles. Lifetime ratio defines the efficiency of the WSN network operation. There are multiple techniques which can help in improvement of Network Lifetime (NL) spanning from transmission nature, data connections, formation of System and time scheduling. This paper provides the analysis of how energy consumption happens and its effect on lifetime ratio. LEACH and CHEF algorithms responsible for hierarchical kind of routing are discussed in detail with simulation results. The parameters used for comparison includes delay, hops, consumption of energy. Non-Hole detection points, Hole detection points, Non-Hole to Hole Ratio, residual energy, routing overhead and throughput.

scholarly journals Enabling thermal efficiency improvement and waste heat recovery using liquid air harnessed from offshore renewable energy sources

2020 ◽  
Vol 275 ◽  
pp. 115351 ◽  
Author(s):  
Julian D. Osorio ◽  
Mayank Panwar ◽  
Alejandro Rivera-Alvarez ◽  
Chrys Chryssostomidis ◽  
Rob Hovsapian ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Efficiency Improvement

scholarly journals Development and Evaluation of Bus Operation Control System Based on Cooperative Speed Guidance

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jing Teng ◽  
Weimin Jin
Keyword(s):  
Control System ◽  
Dwell Time ◽  
Traffic Signal ◽  
Actual Data ◽  
Simulation Platform ◽  
Large Interval ◽  
Operation Control ◽  
Simulation Results

Buses often have strong bunching or large interval tendency when traveling further along the route. To restrain this further deterioration of operation service, this paper developed a bus operation control system to dynamically adjust bus speed, bus dwell time, and traffic signal timings along the running path. In addition, a simulation platform was developed to evaluate the proposed control system with the actual data collected from bus route number 210 in Shanghai. The simulation results show that the proposed control system can mitigate the amplification trend of the headway deviation along the route to produce headways within a given tolerance.

scholarly journals A methodology for designing decentralised energy systems with predictive control for heat pumps and thermal storage

2019 ◽  
Vol 111 ◽  
pp. 06014
Author(s):  
Andrew Lyden ◽  
Paul Tuohy
Keyword(s):  
Predictive Control ◽  
Thermal Characteristic ◽  
Thermal Characteristics ◽  
Energy Systems ◽  
Thermal Storage ◽  
Energy System ◽  
Heat Pumps ◽  
Hot Water ◽  
Water Tank ◽  
Electricity Cost

Decentralised energy systems provide the potential for adding energy system flexibility by separating demand/supply dynamics with demand side management and storage technologies. They also offer an opportunity for implementing technologies which enable sector coupling benefits, for example, heat pumps with controls set to use excess wind power generation. Gaps in this field relating to planning-level modelling tools have previously been identified: thermal characteristic modelling for thermal storage and advanced options for control. This paper sets out a methodology for modelling decentralised energy systems including heat pumps and thermal storage with the aim of assisting planning-level design. The methodology steps consist of: 1) thermal and electrical demand and local resource assessment methods, 2) energy production models for wind turbines, PV panels, fuel generators, heat pumps, and fuel boilers, 3) bi-directional energy flow models for simple electrical storage, hot water tank thermal storage with thermal characteristics, and a grid-connection, 4) predictive control strategy minimising electricity cost using a 24-hour lookahead, and 5) modelling outputs. Contributions to the identified gaps are examined by analysing the sensible thermal storage model with thermal characteristics and the use of the predictive control. Future extensions and applications of the methodology are discussed.

scholarly journals A Study on the Thermal Performance of Air-Type BIPVT Collectors Applied to Demonstration Building

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3120 ◽  
Author(s):  
Ji-Suk Yu ◽  
Jin-Hee Kim ◽  
Jun-Tae Kim
Keyword(s):  
Thermal Performance ◽  
Thermal Characteristics ◽  
Building Energy ◽  
Flow Path ◽  
Heating And Cooling ◽  
Building Integrated Photovoltaic ◽  
Opening Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Inlet Opening

Research on existing air-type PVT (photovoltaic/thermal) collectors has mainly focused on improving the efficiency of the collector itself and on using the energy produced by the collector in heating and cooling facilities and building energy. The first consideration in an air-type PVT system applied to a building facade is the collector arrangement and the flow path considering the collector performance. It is necessary to design the flow inside the air-type BIPVT (building integrated photovoltaic/thermal) collector so that it runs smoothly so as not to cause a dead space and a pressure drop inside the collector, which deteriorate the thermal performance. This study analyzed the thermal characteristics of an air-type BIPVT collector applied to a demonstration building (educational buildings) according to the air flow path and inlet opening ratio. For this purpose, the uniformity of the airflow in the collector was compared through the NX computational fluid dynamics (CFD) program, and the acquired thermal calories and thermal efficiency of the BIPVT collector were compared and analyzed. Based on the simulation results, the temperature and thermal characteristics of the BIPVT collector were compared.

scholarly journals The Impact of Environmental Factors on the Thermal Characteristic of a Lithium–ion Battery

Batteries ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 3 ◽  
Author(s):  
Gerd Liebig ◽  
Ulf Kirstein ◽  
Stefan Geißendörfer ◽  
Frank Schuldt ◽  
Carsten Agert
Keyword(s):  
Lithium Ion Battery ◽  
Thermal Characteristic ◽  
Thermal Characteristics ◽  
Heat Removal ◽  
Lithium Ion ◽  
Air Cooling ◽  
Heat Rejection ◽  
Study Results ◽  
Electrochemical Model ◽  
The Impact

To draw reliable conclusions about the thermal characteristic of or a preferential cooling strategy for a lithium–ion battery, the correct set of thermal input parameters and a detailed battery layout is crucial. In our previous work, an electrochemical model for a commercially-available, 40 Ah prismatic lithium–ion battery was validated under heuristic temperature dependence. In this work the validated electrochemical model is coupled to a spatially resolved, three dimensional (3D), thermal model of the same battery to evaluate the thermal characteristics, i.e., thermal barriers and preferential heat rejection patterns, within common environment layouts. We discuss to which extent the knowledge of the batteries’ interior layout can be constructively used for the design of an exterior battery thermal management. It is found from the study results that: (1) Increasing the current rate without considering an increased heat removal flux at natural convection at higher temperatures will lead to increased model deviations; (2) Centralized fan air-cooling within a climate chamber in a multi cell test arrangement can lead to significantly different thermal characteristics at each battery cell; (3) Increasing the interfacial surface area, at which preferential battery interior and exterior heat rejection match, can significantly lower the temperature rise and inhomogeneity within the electrode stack and increase the batteries’ lifespan.

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