scholarly journals The influence of rotational flexibility of beam-column connection on roof plane rigidity of energy-active cover of frame-purlin hall

2013 ◽  
Vol 12 (2) ◽  
pp. 197-204
Author(s):  
Karolina Brzezińska ◽  
Andrzej Szychowski
Keyword(s):  
Solar Radiation ◽  
Thermal Energy ◽  
Solid Wall ◽  
Space Structures ◽  
Braced Frame ◽  
Transparent Glass ◽  
Rigid Connection

The paper analyses the influence of the rotational flexibility of beam-column connection on the roof plane rigidity of the longitudinally braced frame-purlin cover of the solid wall hall. The cover is adapted to obtain thermal energy from solar radiation. The roof cover is then provided in the form of a transparent glass barrier which requires considerable roof plane rigidity. The analysis aimed to compare the roof plane rigidity of the frame-purlin cover to those of space structures and truss-purlin covers, depending on the type of longitudinal bracing and rotational rigidity of the beam-column connection. The investigations were conducted for three types of roof plane bracing and different rigidity indexes of the beam-column connection (from u=0 – pin connection, through u=0.25; 0.5; 0.75 – semi-rigid connection, to u=1 – rigid connection). In the transfer of horizontal forces, the interaction of the rigidity of frames with flexible nodes (beam-column) with longitudinal roof plane bracings supported by lateral bracings of gable walls was observed. The highest roof plane rigidity was demonstrated by 2X-shaped and K-shaped braces with rigid nodes at frame corners.   

scholarly journals Comparative Modeling of a Parabolic Trough Collectors Solar Power Plant with MARS Models

Energies ◽  
2017 ◽  
Vol 11 (1) ◽  
pp. 37 ◽  
Author(s):  
Jose Rogada ◽  
Lourdes Barcia ◽  
Juan Martinez ◽  
Mario Menendez ◽  
Francisco de Cos Juez
Keyword(s):  
Heat Transfer ◽  
Water Vapor ◽  
Power Plant ◽  
Solar Radiation ◽  
Thermal Energy ◽  
Power Plants ◽  
Solar Power ◽  
Rankine Cycle ◽  
Heat Transfer Fluid ◽  
Solar Field

Power plants producing energy through solar fields use a heat transfer fluid that lends itself to be influenced and changed by different variables. In solar power plants, a heat transfer fluid (HTF) is used to transfer the thermal energy of solar radiation through parabolic collectors to a water vapor Rankine cycle. In this way, a turbine is driven that produces electricity when coupled to an electric generator. These plants have a heat transfer system that converts the solar radiation into heat through a HTF, and transfers that thermal energy to the water vapor heat exchangers. The best possible performance in the Rankine cycle, and therefore in the thermal plant, is obtained when the HTF reaches its maximum temperature when leaving the solar field (SF). In addition, it is necessary that the HTF does not exceed its own maximum operating temperature, above which it degrades. The optimum temperature of the HTF is difficult to obtain, since the working conditions of the plant can change abruptly from moment to moment. Guaranteeing that this HTF operates at its optimal temperature to produce electricity through a Rankine cycle is a priority. The oil flowing through the solar field has the disadvantage of having a thermal limit. Therefore, this research focuses on trying to make sure that this fluid comes out of the solar field with the highest possible temperature. Modeling using data mining is revealed as an important tool for forecasting the performance of this kind of power plant. The purpose of this document is to provide a model that can be used to optimize the temperature control of the fluid without interfering with the normal operation of the plant. The results obtained with this model should be necessarily contrasted with those obtained in a real plant. Initially, we compare the PID (proportional–integral–derivative) models used in previous studies for the optimization of this type of plant with modeling using the multivariate adaptive regression splines (MARS) model.

Comparative Study on the Pseudo-Dynamic Testing of Semi-Rigid Connection of Steel Frames with or without Brace

2011 ◽  
Vol 194-196 ◽  
pp. 2001-2007
Author(s):  
Jia Lv ◽  
Qi Lin Zhang
Keyword(s):  
Dynamic Testing ◽  
Dynamic Test ◽  
Lateral Force ◽  
Steel Frame ◽  
Seismic Loads ◽  
Test Results ◽  
Shearing Force ◽  
Braced Frame ◽  
Rigid Connection ◽  
Steel Braced Frame

The horizontal stiffness of steel frame is relatively weak. So designers introduce brace system into steel frame to increase the horizontal stiffness. In order to guarantee the safety of the structure, we should imitate the performance of the structure under seismic loads. In this paper, the pseudo-dynamic test was conducted on the semi-rigid connection of steel frame and the semi-rigid connection of steel-braced frame. The test results show that the brace can increase the ductility of the structure, decrease the displacement of the top floor, decrease the interlayer displacement, and bear ground floor shearing-force. So the brace greatly impacts the performance of the structure. It has the ability of anti-earthquake and strong resistance ability of lateral force.

Semi-Rigid Connection in Timber Structure: Stiffness Reduction and Instability Interaction

2020 ◽  
Vol 20 (07) ◽  
pp. 2050072 ◽  
Author(s):  
A. Manuello
Keyword(s):  
Joint Stiffness ◽  
Structural Response ◽  
Actual Condition ◽  
Space Structures ◽  
Beam Elements ◽  
Stiffness Reduction ◽  
Rigid Connection ◽  
Geometrical Imperfections ◽  
The Stability ◽  
Rigid Joints

Latticed shells and domes usually consist of hundreds, sometimes thousands, beam elements connected by rigid or semi-rigid joints. These connecting elements result, generally, very sophisticated, made with different materials and constituted by disparate connection systems. Recently, the stiffness connections were studied, numerically and experimentally, as one of the most important factors influencing significantly the structural response of space structures and domes. Very often, in the design process, the joints are assumed to be hinged or clamped. This assumption may result significantly far from the actual condition of in-service structure and components, leading to not understanding or not being able to prevent sudden catastrophic collapses (buckling, snap-through). Thus, the inclusion of joint stiffness reduction in the numerical model is necessary, more and more also due to the types of external loads, such as overloads that occur during the life of the structure or, especially, seismic solicitations. In this paper, the stability of an existent timber dome has been studied increasing the yieldingness of the connecting nodes according to an original approach. In addition, sensitivity of this kind of structure to the amplitude and the geometrical imperfections shape have been also considered. Numerical analyses have been conducted with local displacement controls, to take into account the geometric nonlinearity effects. Results evidenced that the dome is affected by instability interaction for particular slenderness and stiffness reduction of the connections.

scholarly journals Research on Dynamic Balance Adjustment Method of Single Braced Frame Gyroscope Rotor

2019 ◽  
Vol 256 ◽  
pp. 02005
Author(s):  
Xukui Hou ◽  
Ende Wang ◽  
Hui Cao ◽  
Yalong Zhu ◽  
Kai Qi
Keyword(s):  
Mass Distribution ◽  
Degrees Of Freedom ◽  
Dynamic Balance ◽  
Dynamic Balancing ◽  
Braced Frame ◽  
Rigid Connection ◽  
Rotational Degrees Of Freedom ◽  
Vibration Rotation ◽  
Rotor Mass ◽  
Rotation Component

The uneven mass distribution of gyro rotors results in vibration, rotation and drift of gyro rotors, which seriously affect the performance index and life of gyro rotors. However, because there is no rigid connection between the rotary shaft and the shell of the gyro rotor, the dynamic balancing machine can only balance the vibration component of the single braced frame gyroscope rotor, and can’t measure the gyro rotor’s rotation component. By analyzing the influence of uneven rotor mass distribution on the gyro rotor performance, a method of eliminating two rotational degrees of freedom of the gimbal in gyro rotor by mandrel is proposed, which makes the dynamic balancing machine directly measure the vibration component and the moving component of the gyroscope rotor, and simplifies the dynamic balancing debugging process.

Assessing underground heat exchange and solar heat storage capabilities based on ground thermo-physical properties: the Euganean hills demo site (Italy)

2020 ◽  
Author(s):  
Eloisa Di Sipio ◽  
Raffaele Sassi ◽  
Stefano Buggiarin ◽  
Silvia Ceccato ◽  
Antonio Galgaro
Keyword(s):  
Solar Radiation ◽  
Physical Properties ◽  
Thermal Energy ◽  
Heat Storage ◽  
Residential Buildings ◽  
Renewable Energy Sources ◽  
Methodological Approach ◽  
Solar Thermal ◽  
North East ◽  
Thermo Physical Properties

<p>The utilization and development of renewable energy sources (RES) is currently a topic of great interest in energy field. In detail, the coupling of different RES and related technologies, as solar thermal and shallow geothermal, for heating/cooling purpose of residential buildings is a promising sector. The possibility to store the thermal energy produced by solar panels in the underground during the summer season, when the insolation is greater, and to use the heat accumulated during the coldest periods, is strictly related, among others, both to the thermo-physical properties of rocks and to the solar radiation locally available. As the ground is the invariant component of the whole system, a better knowledge of its thermal properties (i.e. thermal conductivity, volumetric heat capacity…) is fundamental to evaluate the amount of heat that can be stored.</p><p>This paper presents an innovative methodological approach combining information related to underground thermal energy exchanging and storage capacity with the solar radiation, taking also into account the location of the possible end-users, that is the distribution of the residential buildings in the territory. The Euganean Hills area, located in the Po River Plain (north-east Italy), is selected as demonstration test site. A qualitative map, created using Geographycal Information System (GIS) application, has been realized in order to represent the “Ground thermal suitability” of a territory to sensible heat storage, that is the possibility to store solar energy in the underground for a later use.</p><p>This thematic map is a really promising tool, suitable for local administrator and professionals, for planning the possible exploitation of solar thermal renewable resources available in the area.</p>

Ultraviolet-Visible Light-Thermal Conversion Organic Solid-Liquid Phase-Change Materials

2013 ◽  
Vol 679 ◽  
pp. 29-34
Author(s):  
Yun Ming Wang ◽  
Bing Tao Tang ◽  
Shu Fen Zhang
Keyword(s):  
Energy Storage ◽  
Liquid Phase ◽  
Solar Radiation ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Thermal Conversion ◽  
Organic Solid ◽  
Solid Liquid

UV-vis light-driven organic solid-liquid phase change materials exhibited excellent performances of UV-vis light-harvesting, UV-vis light-thermal conversion and thermal energy storage, which is promoted by UV absorbing dye as an effective ‘‘photon capture and molecular heater’’ for direct and efficient use of solar radiation.

Cogenerative PV Thermal Modules of Different Design for Autonomous Heat and Electricity Supply

2018 ◽  
pp. 86-119 ◽  
Author(s):  
Valeriy Kharchenko ◽  
Vladimir Panchenko ◽  
Pavel V. Tikhonov ◽  
Pandian Vasant
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Thermal Energy ◽  
Heat Supply ◽  
Electricity Production ◽  
Electricity Supply ◽  
Well Testing ◽  
Pilot Studies ◽  
Solar Water Heating ◽  
Advantages And Disadvantages

Solar energy is used for electricity production by means of photovoltaic modules and for heat supply by means of solar water-heating collectors. In recent years, combined cogeneration photovoltaic thermal modules which work out at the same time both electricity and thermal energy began to be applied actively. The chapter includes consideration of the main types of cogenerative photovoltaic thermal modules of different design such as planar liquid devices as well as devices with concentrator of solar radiation. The advantages and disadvantages of each type are presented. Main directions for improving the efficiency of converting solar energy into thermal and electricity are offered. The description of the offered construction of the module, and also results of theoretical and pilot studies of the module is provided in full-scale conditions. Installation for such tests is described as well. Testing photovoltaic thermal modules with planar and concentrator design are presented in the chapter.

scholarly journals Energetic and exergetic analysis of solar photovoltaicthermoelectric generator hybrid system

2021 ◽  
Vol 17 (2) ◽  
pp. 256-261
Author(s):  
Parul Mertia ◽  
Surendra Kothari ◽  
N.L. Panwar
Keyword(s):  
Solar Radiation ◽  
Electric Power ◽  
Hybrid System ◽  
Thermal Energy ◽  
Second Law Of Thermodynamics ◽  
Climatic Conditions ◽  
Output Performance ◽  
Calculation Results ◽  
Exergetic Analysis ◽  
Exergy Performance

The objective of present study is to determine the energy and exergy performance of the developedSolar Photovoltaic- Thermoelectric generator hybrid system. The experimental setup was examined under Udaipur climatic conditions (24°352 73 N; 73°422 453 E). The hybrid systems convert sunlight into electric power by the PV module and then utilize the rest thermal energy by the TEG module. Based on the first law of thermodynamics, the energy analysis is used to evaluate the output performance of the hybrid system. And the output electric power of the hybrid system is calculated. Moreover, the second law of thermodynamics is applied to the exergy analysis of the hybrid system. The exergy losses caused by the irreversible process of solar radiation converted into electric power and thermal energy are evaluated. The calculation results demonstrate that exergy of system follows the incident solar radiation and most of the input exergy has been lost at output with maximum losses occur when solar radiations are converted into heat.

Rooftop and Attic Area Thermal Energy from Solar Radiation as Renewable Energy in Malaysia

2021 ◽  
Author(s):  
Muhammad Nazri Rejab ◽  
Muhammad Akmal Johar ◽  
Wan Akashah Wan Jamaludin ◽  
Umar Abubakar Saleh
Keyword(s):  
Renewable Energy ◽  
Solar Radiation ◽  
Thermal Energy
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