Influence of the thermal insulation layer on radial stress and collapse resistance of subsea wet insulation pipe

Fire overflow on exterior wall with thermal insulation system has been studied by numerical simulation. The spread laws of fire overflow are analyzed through the temperature distribution near the window. The computational results are compared with those of test in the Exterior Insulation Fire Barrier Technical Guidelines (EIFBTG). It has been found that the calculated maximum temperature points is closed to the test on the first floor, the first ceiling, and the points near the above two windows. However, there are differences between two kinds of results above two floors and ceilings, and the points near the first window. It has also shown that when the HHR is 7.5KW, the scope of damage of exterior thermal insulation layer is about 15 square meters near the window. The research would provide reference for fire protection design of exterior wall thermal insulation in the high-rise buildings.

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Inverted roof insulation kits and their durability

MATEC Web of Conferences ◽

10.1051/matecconf/201816308005 ◽

2018 ◽

Vol 163 ◽

pp. 08005 ◽

Cited By ~ 1

Author(s):

Barbara Francke ◽

Robert Geryło

Keyword(s):

Water Absorption ◽

Thermal Insulation ◽

Laboratory Tests ◽

Expanded Polystyrene ◽

Insulation Layer ◽

Performance Properties ◽

Climate Conditions ◽

Freeze Thaw ◽

Moisture Increase

In the paper there was analyzed a mechanism of loss of performance properties of inverted roof insulation kits resulted by moisture increase of the insulation layers. This problem is very important in such systems because the thermal insulation is placed above the waterproofing layer and is not protected against water absorption. Abovementioned problem is more and more common in the course of building’s utilization in Polish climate conditions. Because inverted roof kits are based on extruded polystyrene (XPS) and expanded polystyrene (EPS), those materials have been used in tested samples. The results of laboratory tests showed the phenomenon and its effect on durability and sustainability of roof covering performance. It was also found that the biggest influence on the increase of moisture in the thermal insulation layer has not the long term water absorption by immersion but freeze –thaw cycles.

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Investigation of the Insulation Effect of Thermal Insulation Layer in the Seasonally Frozen Region Tunnel: A Case Study in the Zuomutai Tunnel, China

Advances in Civil Engineering ◽

10.1155/2019/4978359 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

Pengyu Zhao ◽

Jianxun Chen ◽

Yanbin Luo ◽

Lijun Chen ◽

Yao Li ◽

...

Keyword(s):

Thermal Insulation ◽

Air Temperature ◽

Ground Surface ◽

Maximum Temperature ◽

Insulation Layer ◽

Tunnel Length ◽

Maximum Temperature Difference ◽

Insulation Effect ◽

Two Sides

In this study, a field temperature test was performed to reveal the insulation effect of the thermal insulation layer installed at lining surface. The thermal insulation layer is made of polyphenolic, and the thickness is 7 cm. According to the test results, the temperature of the thermal insulation layer and lining continuously changes with the air temperature in the tunnel in an approximately trigonometric function. The temperature of tunnel lining without thermal insulation layer is close to the air temperature, which results in the lining frost in winter. The maximum temperature difference between the two sides of the thermal insulation layer can be 27°C. In the section whose buried depth is more than 11.4 m, the temperature of lining with thermal insulation layer in winter is mainly influenced by the cold air in the tunnel. When the monthly mean and lowest daily mean air temperature are lower than −10°C and −14.3°C in the coldest month, the temperature at the inner side of the thermal insulation layer is below 0°C. When the buried depth is less than 11.4 m, the temperature of lining is also influenced by the low temperature at ground surface. The temperature of lining is lower. The thicker thermal insulation layer and even active heat measure are needed. Therefore, the design of thermal insulation layer thickness should consider the air temperature distribution and tunnel buried depth along the tunnel length.

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Feasibility of Using Modified Silty Clay and Extruded Polystyrene (XPS) Board as the Subgrade Thermal Insulation Layer in a Seasonally Frozen Region, Northeast China

Sustainability ◽

10.3390/su11030804 ◽

2019 ◽

Vol 11 (3) ◽

pp. 804 ◽

Cited By ~ 3

Author(s):

Qinglin Li ◽

Haibin Wei ◽

Leilei Han ◽

Fuyu Wang ◽

Yangpeng Zhang ◽

...

Keyword(s):

Numerical Simulation ◽

Thermal Insulation ◽

Oil Shale ◽

Pollution Index ◽

National Standards ◽

Silty Clay ◽

Insulation Layer ◽

Insulation Property ◽

Thermal Insulation Property ◽

Seasonally Frozen Regions

To achieve the purposes of storing industry solid wastes and enhancing subgrade stability in seasonally frozen regions, Structure III, which utilized the modified silty clay (SC) and extruded polystyrene (XPS) board as a novel subgrade thermal insulation layer (NSTIL), was presented. The above modified SC consisted of oil shale industry solid waste, fly ash and SC. In terms of environmental impact, the average single pollution index, the Nemerow integrated pollution index and national standards were carried out to estimate whether the modified SC could be used as a subgrade filler. These results show that, although the modified SC will produce pollution to the environmental background, the concentration of each hydrochemical constituent from the modified SC meets the corresponding national standards in China. In terms of the thermal insulation capability, the numerical simulation of coupling moisture and temperature was applied to analyze that of Structures I, II and III. The research results show that the numerical results of the Structure I are approximated to the official website information of Jilin province, indicating that the above numerical simulation is effective for coupling moisture and temperature of frozen soil. Both modified SC and NSTIL have the advantage of good thermal insulation property, but the thermal insulation property of the NSTIL is greater. Furthermore, the NSTIL at the top of the Structure III can protect the SC of the experimental road from the damage of frost heave. The research results are of great significance for reducing environmental pollution caused by oil shale industry solid waste and fly ash, increasing the utilization rate of industrial waste and enhancing the subgrade stability in seasonally frozen regions.

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Cooperative Performance of Sandwich Insulation Walls With Expanded Polystyrene Under Static Loads

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.602-604.948 ◽

2012 ◽

Vol 602-604 ◽

pp. 948-951

Author(s):

De Ling Wang ◽

Zhong Li

Keyword(s):

Numerical Simulation ◽

Thermal Insulation ◽

Expanded Polystyrene ◽

Vertical Load ◽

Exterior Wall ◽

Insulation Layer ◽

Static Loads ◽

Interface Friction ◽

Ring Shape ◽

Concrete Blocks

Sandwich insulation walls can bear loadings and insulate thermal which are fit for cold and freezing areas. In this paper, small-sized concrete hollow blocks are selected as interior and exterior wall; expanded polystyrene (EPS) plates are selected as thermal insulation layer which are put between inner and outer layers. Effects of several factors on cooperative performance of interior and exterior wall under static loads were analyzed by numerical simulation. These factors include the type of connection steel, the vertical load and the property of interface between EPS and concrete blocks. The results show that among the connection steel of ‘Z’ shape, ring shape and tie netting, the last is the best. Displacement difference between interior and exterior walls increases with increasing vertical load. And if the interface friction between EPS block and concrete blocks is considered, displacement and displacement difference of sandwich walls all increase. These results agree with similar tests.

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Analysis of Heat Loss of Ground Pipeline of Thermal Production Oilfield

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.90-93.3057 ◽

2011 ◽

Vol 90-93 ◽

pp. 3057-3060 ◽

Cited By ~ 1

Author(s):

Jian Jun Liu ◽

Gui Hong Pei ◽

You Jun Ji

Keyword(s):

Heat Transfer ◽

Layer Thickness ◽

Heat Loss ◽

Thermal Insulation ◽

Oil Recovery ◽

Heavy Oil ◽

Insulation Layer ◽

Obvious Effect ◽

Steam Pipeline ◽

Heat Transfer Theory

Steam stimulation is one of the main methods used in heavy oil reservoir development. How to inject high temperature and high dryness steam is a key factor to enhance heavy oil recovery. It is significant to evaluate heat transfer of steam pipeline and optimize thermal insulation layer for heavy oil exploitation. Based on fluid mechanics, heat transfer theory, considered phase change, mathematical model to calculate heat transfer and heat loss of steam pipeline was derived. Using COMSOL Multiphysics, a finite element based program for simulating unlimited multiphysics and single physics applications, the author simulated heat transferring in ground steam pipeline and analyzed the effect of thermal insulation layer. From the simulation results, it was known that, (1) Along with the pipeline distance increases, the steam dryness decreases, the decrease rate decreases with the distance increases. (2) At the same transmission distance, the bigger the thermal insulation layer thickness is, the smaller the heat loss of the steam is. The heat loss of steam transmission mainly center on the first half pipeline. (3) With the thickness of thermal insulation layer increases, the heatloss declines. After the thickness of thermal insulation layer increases 90 mm, increasing the thickness has no obvious effect on reducing the heat loss. So, it is suggested that the thermal insulation layer thickness should be 75-80mm.

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