Insulation Cover Research Articles

GENIUS: A methodology to define a detailed description of buildings for urban climate and building energy consumption simulations

Urban canopy parametrisations like the Town Energy Balance TEB solve the urban surface energy balance for a simplified urban morphology in order to provide the lower boundary conditions for atmospheric models in urban areas. The urban surface energy balance is influenced in various ways by physical parameters related to building architecture. The albedo of the covering materials of roofs and walls is crucial for the radiation balance, the thermal conductivity and thermal capacity of the construction materials influence the heat storage inside the urban fabric. In this study we introduce a methodology to define the characteristics of building architecture with the precision required by state of the art urban canopy parametrisations. The geographical scope of our analysis is France. We assume that the building architecture depends mainly on the urban typology, the building use, the construction period, and the geographical location. Based on a literature survey on architectural practices and building regulation standards in France we define one to three building archetypes for each combination of these four parameters. For each building archetype, information on the construction type of walls and roofs (main materials, insulation, internal and external cover), the glazing ratio, type of windows, presence of shading elements, the airtightness and presence of a mechanical ventilation system is provided. We perform idealised simulations with TEB to determine the sensitivity of the urban surface energy balance on building architecture. We find that the albedo of the roof and the presence of insulation materials in wall and roof as well as their position with respect to the main wall and roof material are crucial for an accurate simulation of the urban energy balance. Future developments of the architectural database will therefore focus on these parameters.

Experimental Study on Ventilation and Thermal Performance of Exterior Sandwich Wall Based on Hot Box Method

In this paper, the thermal performance of a sandwich ventilation wall was studied based on the hot and cold box. The model consists of two types of cover plates: wall thermal insulation set and non-set. We tested the surface temperature, air temperature and the heat flux density of air interlayer in three different forms of airflow within the wall. The experiment results show that introducing fresh air from the outside in cold areas in winter will not affect the thermal insulation performance of the wall if the hole openings are reasonably organized. Compared with the traditional exterior wall, the air flow rate and pressure increase in the structure of the air layer can improve the thermal performance of the sandwich wall. By com-paring the two kinds of wall heat transfer coefficienies of the non-thermal insulation cover plate and the thermal insulation cover plate, it is found that the thermal insulation design of the cover plate can further improve the thermal performance of the sandwich wall by 12.3%.

Anode Geometry Effects on Ion Beam Energy Performance in Helicon Electrostatic Thruster

The ion beam energy performance in a helicon electrostatic thruster with various anode geometries was investigated. For discharge voltages from 100 to 300 V, the ion beam energy increased almost linearly with the discharge voltage. The rate of increase strongly depended on the anode inner diameter (ID). However, the ion beam energy was fit to a single linear function of the total input power irrespective of the anode ID. The effect of an insulation cover set on the side wall of the anode depended on the anode ID; while with the anode ID being equaled to that of the helicon source tube, i.e., 27 mm, the ion beam energy was decreased by about 30%, with the anode ID of 40 mm the electrostatic acceleration became negligible. Under typical operation conditions, the ion beam energy had a flat-hat profile with a diverging angle of 47°; the specific impulse, thrust efficiency, and propellant utilization efficiency evaluated from probe survey measurements were 2000 s, 9.7%, and 98%, respectively.

Feasibility Study of Sitting Posture Monitoring Based on Piezoresistive Conductive Film-Based Flexible Force Sensor

A study was conducted to develop a force sensor made of piezoresistive conductive film and to assess the feasibility of detecting inappropriate sitting postures using the force sensor platform. The force sensor was designed with multiple layers and includes a conductive foil and an insulation cover. The sensor delivers voltage output according to its power-law characteristics in response to a change in the applied force. The distribution of pressure was measured for three postures—upright, forward leaning, and backward leaning—using a three-by-three sensor array attached to a chair. The results indicate that the ratio of the average pressure distribution on the front row to that on the rear row of the sensor array exhibits a significant variation.

Performance improvement of the finned passive PVT system using reflectors like removable insulation covers

A passive photovoltaic–thermal system (PVT) is the combination of a photovoltaic (PV) panel and a compact solar water heater for co-generation of heat and electricity. This system bears considerable heat losses to ambient, particularly at noncollection times. One simple way to overcome this problem is to use a removable insulation cover on the collector's outer glazing. In this paper, the effects of the reflectors on day and night performance of a finned passive PVT system were numerically studied. At nonenergy collection time, the reflectors can turn and cover the collector cover glass as a nonconductor material. Simulation results showed that the reflectors reduce the night heat losses and increase the solar radiation rate on the absorber plate. The use of removable insulation reflectors resulted to saving extra sensibly thermal energy. Also, the solar cells power generation (Psc), in the case of reflectors installed, was reinforced.

Protecting trapped animals from heat exposure: the influence of shading on temperature within small metal box traps

Animal research guidelines recognise that trapped animals can potentially be subjected to heat stress, but recommendations are limited to avoiding exposing traps to weather extremes. Intuitively, shading metal box traps should be beneficial in warm to hot climates. Temperatures inside metal box traps were measured within traps located in direct sunlight concurrently with ones covered with artificial shading. Additionally, comparisons were conducted in continuous shade cast by ground-cover vegetation, and in stippled sunlight under an artificial lattice. Deep continuous shade from vegetation was most effective and able to keep traps within 5°C of ambient. Artificial shading using dark shade cloth could actually elevate trap temperatures above that in uncovered traps when exposed to direct sunshine. Reflective foil insulation cover not only provided rain protection for traps but was the most effective shading method trialled for reducing both the rate at which traps heated after sunrise and the maximum temperature reached during the day when exposed to direct sunshine. The use of foil sleeves can provide an extra level of protection from excessive heat exposure to trapped animals, keeping trap temperatures as much as 15°C lower than unprotected traps.

Effect of DROF Process on the Temperature Field and Roll Force

The key technology of direct rolling of free heating for bar and rod mill (DROF) was briefly introduced. Compared with the traditional process, the DROF can reduce energy consumption and emission, so as to decrease the production cost. It is very important to understand temperature field of continuous casting billet (CC-billet) to carry out the research on DROF technology. In order to reduce the loss of heat, the insulation cover is used, so it can effectively reduce the roll force and motor power. The rolling parameters, such as roll force and power, in former 4 stands of roughing mills were investigated by finite element method (FEM). The results show that the average temperature of the CC-billet after 300s from the cutting time can still be over 970°C, it can meet the need of direct rolling.

Cork: a strategic material.

Cork: a strategic material.

1109 穴あき矩形カバーの遮音性能予測に関する研究

Noise and vibration control are the one of important issues for engineering. A sound insulation cover which envelops a sound source is very useful for the noise reduction. When large noise and high temperature heat are emitted from the sound source, we have to consider the heat cooling as well as the noise reduction. The purpose of the present study is to investigate the acoustic characteristic of a sound insulation cover with and without a small hole using acoustic/structure coupled analysis. The effect of hole size and position were also investigated. Although a lot of sound leaked from a large size hole, a small size hole hardly influenced the sound insulation performance of the cover. It is clearly that sound pressure distributions around the cover changed obviously according to the input frequency of a sound source.

Design for fire of concrete elements strengthened or reinforced with fibre-reinforced polymer: state of the art and opportunities from performance-based approaches

Recent years have seen widespread success applying fibre-reinforced polymer (FRP) materials for internal reinforcement and externally bonded strengthening of concrete structures. However, considerable reductions in mechanical and bond properties of FRP materials at elevated temperatures continue to hinder their application in buildings, where structural fire-resistance ratings are typically required. To meet currently imposed fire safety requirements, FRP materials often require supplemental fire protection insulation or thick concrete cover to maintain their temperature below an assumed (though not currently well-defined) “critical” value during an assumed standard fire exposure. Such requirements are based on a definition of structural fire resistance that is rooted in a prescriptive framework and that fails to take advantage of the state of the art in performance-based structural design for fire safety. This paper is intended to present a summary of the state of the art in this area and also to demonstrate clear opportunities for internal FRP reinforcement and external FRP strengthening of concrete elements that may arise from taking a performance-based fire safety design approach.

An Improved Insulation System for the LHC Main 13 kA Interconnection Splices

In 2013, a long shutdown of the Large Hadron Collider at CERN will allow comprehensive maintenance plus consolidation of the machine components, in particular of the 13 kA circuits that feed the main superconducting magnets around the 27-km ring. This shutdown will prepare the accelerator for operation at nominal energy, 14 TeV, with adequate margin on the critical performance parameters. An essential part of the consolidation program consists of adding to the 13 kA splices of the magnet interconnects a copper shunt of high RRR(> 300) that will carry the current in the event of a busbar quench. An important R&D program was conducted in 2010 to design a sound solution for the shunt and for an improved insulation system. The development of the insulation system has required iterations aiming at an adequate solution. The functional requirements for the insulation are a breakdown voltage of at least 3.1 kV in superfluid helium and sufficient mechanical strength to withstand stresses of the order of 50 MPa. The insulation system shall provide mechanical restraint for the shunted splices so that their transversal deflection is limited to 0.25 mm. This paper describes the final design of the insulation and the optimization process. The results from dielectric tests and numerical optimization of the insulation cover will be also presented. Finally, the performance of the new insulation will be compared to the previous version.

1101 音源位置を考慮した気柱共鳴現象の検討(OS11-1 流体関連振動・騒音,OS11 流体関連振動・騒音)

Noise and vibration control are the one of important issues. A sound insulation cover which covers a sound source is very useful for the noise reduction. The purpose of the present study is to investigate the acoustic characteristic of a sound insulation cover using acoustic/structure coupled analysis. It is clearly that sound pressure distributions inside and outside cover changed obviously according to the input frequency of a sound source. Several peaks of the sound pressure level were observed and these peaks were depended on the natural frequency and the resonance frequency of the insulation cover. Detail characteristic of the acoustic resonance phenomena was investigated and the mode of acoustic resonance changed by the sound source position.

G050054 線-平行平板型EHDガスポンプにおける絶縁被覆法のポンプ特性への影響

In recent years, a variety of EHD gas pumps have been experimentally and analytically investigated and developed for heat and fluid transportations. The purposes of this study are to develop pumping capability of a wire-parallel plate type EHD gas pump and to give the optimum design guideline. In this study, experiments have been conducted to study effects of an angle of the insulation cover for wire electrode and a position of that for ground electrode on time averaged discharge current, gas velocity, volumetric flow rate and efficiency. In addition, the method on the partial insulation cover of the corona wire was tested with insulation spray in order to miniaturize the EHD gas pump. The experiments were conducted under atmospheric pressure and room temperature, where air was used as the working fluid. Experimental results show that: (1) Maximum average gas velocity of 3.4 m/s at the channel exit of 5 mm in height and 10 mm in width was observed for ground cover type EHD gas pump; (2) The average gas velocity, volumetric flow rate and efficiency considerably were higher for ground cover type EHD gas pump than that for wire cover type one; (3) The net gas flow was generated by the EHD gas pump with a wire sprayed partially and thin insulation material.

110 音響/構造連成解析による遮音カバー内部の音響特性(振動・音響の解析と測定)

The noise and vibration control are the one of important issues. A sound insulation cover which covers a sound source is very useful for the noise reduction. The purpose of the present study is to investigate the acoustic characteristic of a sound insulation cover using acoustic/structure coupled analysis. To verify the numerical results, experimental measurement of sound pressure level was also carried out. It is clearly that sound pressure distributions inside and outside cover changed obviously according to the input frequency of a sound source. Several downward peaks of the sound insulation were observed and these peaks were depended on the natural frequency of the insulation cover. Numerical and eχperimental results were consistent qualitatively.

The Design of the Detonator Wick Resistance Auto-Stripping Detector

This paper introduces an online auto-monitoring instrument which can automatically slice the external insulation cover of the leading wire and accurately measure the wick resistance in the assembly line of the detonator wick resistance. With safety protection circuit, constant current source is employed to measure the resistance, endowing the design with high accuracy, safety protection features and high degree of automation. It is expected to change the traditional production process where manual work has been used to measure and collect statistics, hence could greatly improve labor productivity as well as product quality and produce favorable application and promotion value.

Design and Theoretical Analysis of Acoustic Enclosure for G12V190 Type Diesel Engine

The existing acoustic cover is improved to reduce the noise of G12V190 type diesel engine. A panel of shutters structure is designed and simulated with SYSNOISE. The structure of acoustic enclosure is also been designed according to the structure of the diesel engine. Theoretical calculation shows that the improved insulation cover has not only a good noise reduction effect, but also has been greatly improved in terms of cooling ventilation, the field test results also shows that this section of acoustic enclosure can reduce the noise about 10dB.

Wire-rod type electrohydrodynamic gas pumps with and without insulation cover over corona wire

The effect of an insulation cover on a corona wire for a wire-rod type electrohydrodynamic (EHD) gas pump was experimentally investigated and one-dimensional cross sectional averaged analyses were performed. The insulation cover over the corona wire causes a fluctuation of the discharge current, resulting in fluctuations of the EHD gas flow. The insulation cover also changes the EHD force distribution, which is the product of an electric field and ion charge density. The EHD force concentrated at the center of the flow channel, and was directed toward the rod electrode in a straight line. Thus the rod electrode supposed to become a significant disturbance to the flow. The flow velocity fluctuations and the modified distribution of the EHD force with the insulation cover enlarged the flow head losses, and eventually resulted in smaller flow velocity than that without the insulation cover over the corona wire.

옥외용 LED 조명의 전기화재 위험성 평가기법에 관한 연구

In this paper, we experimented and analyzed about electric fire risk assessment methods of LED lightings for outdoor. LED lighting is composed of AC power lines, AC/DC converter, DC power lines and LED lamps. There are some risk factors of electric fire in LED lighting such as short circuit between power lines or power line and ground, dielectric breakdown, leakage current, abnormal voltage inflow, poor contacts(connections), etc. As a result of this study, insulation coverings of wire was ignited due to dielectric breakdown between power lines and molten marks were formed in copper conductor. LED lighting was blown out while short circuit, beside that, electrical disorder did not occur. When abnormal voltage was inflowed, electronic components such as varistor, condenser were damaged. Partial heating was produced and insulation was melted and carbonized by arc and heating while poor contacts were happened. We expect that the results of this study would be helpful for electrical safety of LED lightings for outdoor.

Application of Dual-Mode Switching Threshold Controller to Autonomous Carrier Robot

Cleaning the insulation coverings of high voltage power transmission is effective to prevent the flashover accident. This paper designed a climbing robot as carrier platform which composed of spiral wheel and covering. The control system consists of Single Chip Microcomputer (SCM), stepping motor and ultrasonic distance-measuring sensors. Based on switching threshold theories, a compound fuzzy-PID controller was studied. Then the mathematical model of automatic system was simulated by Simulink Toolbox of Matlab. Finally, data of carrier experiments based on closed loop control validated the effectiveness of the controller.

Increase of sound proofing of air duct

One of ways of noise protection from transit air duct is increase of sound insulation of air duct by different acoustical materials. The main interest of this work is in comparative analysis of acoustic efficiency different thermal insulation materials for use as sound insulation coverings. The report contains analysis of the distribution of noise through round and rectangular air ducts. There was discovered different tipes of thermal insulation materials such as easy made foam materials and fibrous materials. Tests are executed in the reverberation chamber. The received results have shown advantage of a fibrous material.