Calculation and Analysis of structural stress optimization of high temperature reheated steam pipe

2020 ◽  
Author(s):  
Xin Liu ◽  
Yan-Ming Zhang ◽  
Qun Liu ◽  
Liang Zhou ◽  
Guo-Quan Xue ◽  
...  
Keyword(s):  
High Temperature ◽  
Structural Stress ◽  
Stress Optimization ◽  
Steam Pipe

Creep Properties of Steels Utilized in High-Pressure and High-Temperature Superheater and Steam Pipe Practice. Part I: Carbon Steels

1944 ◽  
Vol 151 (1) ◽  
pp. 54-62 ◽  
Author(s):  
H. J. Tapsell
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Carbon Steels ◽  
Creep Properties ◽  
Molybdenum Steel ◽  
Steam Pipe ◽  
Steam Pipes ◽  
Sufficient Precision ◽  
Creep Strains

This report deals with the creep properties of carbon steels used in superheater headers, superheater tubes, and steam pipes for service at temperatures up to about 480 deg. C. The object of the investigation was to obtain data for the estimation of the stress-temperature relationships for specific creep strains of 0·1–0·5 per cent to occur in 100,000 hours, and these have been obtained with sufficient precision to warrant their acceptance for practical purposes. Similar components in molybdenum steel are under investigation.

scholarly journals Influence of the Spacing of Steam-Injecting Pipes on the Energy Consumption and Soil Temperature Field for Clay-Loam Disinfection

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3209 ◽  
Author(s):  
Zhenjie Yang ◽  
Xiaochan Wang ◽  
Muhammad Ameen
Keyword(s):  
Heat Transfer ◽  
Energy Consumption ◽  
High Temperature ◽  
Soil Temperature ◽  
Relative Energy ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Loam Soil ◽  
Steam Pipe ◽  
Steam Heat

Soil steam disinfection (SSD) technology is one of the effective means to eliminate soil-borne diseases, especially under the condition of clay-loam soil cultivation for facility agriculture in Yangtze River delta (China). With the fine particles, small pores and high density of the soil, the way of steam transport and heat transfer are quite different from those of other cultivation mediums, and when using SSD injection method, the diffusion of steam between pipes will be affected, inhibiting the heat transfer in the dense soil. Therefore, it is necessary to explore the influence of steam pipe spacing (SPS) on the energy consumption and soil temperature (ST) for clay-loam disinfection. The best results are to find a suitable SPS that satisfies the inter-tube steam that can be gathered together evenly without being lost to the air under limited boiler heating capacity. To this purpose, we first used a computational fluid dynamics model to calculate the effective SPS to inject steam into deep soil. Second, the ST, ST rise rate, ST coefficient of variation, and soil water content variation among different treatments (12, 18, 24, or 30 cm pipe spacing) were analysed. Finally, the heating efficiency of all treatments depending on the disinfection time ratio and relative energy consumption was evaluated. The result shows that in the clay-loam unique to Southern China, the elliptical shape of the high-temperature region obtained from the numerical simulation was basically consistent with the experiment results, and the ratios of short diameter to long diameter were 0.65 and 0.63, respectively. In the SPS = 12 and 18 cm treatments, the steam completely diffused at a 0–20 cm soil layer depth, and the heat transfer was convective. However, at an SPS = 12 cm, steam accumulation occurred at the steam pipe holes, causing excessive accumulation of steam heat. The relative energy consumptions for SPS = 30, 24, and 12 cm were above 2.18 kJ/(kg·°C), and the disinfection time ratio was below 0.8. Thus, under a two-pipe flow rate = 4–8 kg/h, the inter-tube steam was found to be completely concentrated with a uniform continuous high temperature distribution within the soil for an appropriate SPS = 18–22 cm, avoiding the unnecessary loss of steam heat, and this method can be considered for static and moving disinfection operations in the cultivated layer (−20–0 cm) of clay loam soil. However, for soil with higher clay contents, the SPS can be appropriately reduced to less than 18 cm. For soil with lower clay contents and higher sand contents, the SPS can be increased to more than 22 cm.

Creep Properties of Steels Utilized in High-pressure and High-temperature Superheater and Steam Pipe Practice. Part II: 0·5 per cent Molybdenum Steels

1945 ◽  
Vol 153 (1) ◽  
pp. 181-192 ◽  
Author(s):  
H. J. Tapsell ◽  
R. W. Ridley
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Carbon Steels ◽  
Creep Properties ◽  
Superheater Tube ◽  
Steam Pipe

This report deals with the creep properties of carbon-molybdenum steels in the form of a superheater header, superheater tube, and steam pipe manufactured for service at temperatures above about 450 deg. C. (842 deg. F.). The investigation was carried out in a similar manner to that described in Part I (Proceedings, 1944, vol. 151, p. 54) which dealt with carbon steels and, as in the former case, the object was to obtain data for the estimation of the stress-temperature relationships for from 0·1 to 0·5 per cent creep in various periods up to 100,000 hours. It is considered that the data provide a satisfactory basis for design.

Creep Characteristics and Micro-Defects of Main Steam Pipe Steel at High Temperature

2006 ◽  
Vol 326-328 ◽  
pp. 1129-1132
Author(s):  
C.S. Jeong ◽  
Bum Joon Kim ◽  
Byeong Soo Lim
Keyword(s):  
High Temperature ◽  
Void Nucleation ◽  
Early Stage ◽  
Pipe Material ◽  
P92 Steel ◽  
Micro Cracks ◽  
Creep Characteristics ◽  
Martensite Packet ◽  
Steam Pipe ◽  
Main Steam

The initiation and growth of micro-defects such as micro cracks and voids usually causes the failure of long term operated structural components at high temperature. In this study, the creep characteristics and void nucleation and growth characteristics of P92 steel which is used as main steam pipe material in power plant were investigated at several temperatures and loading conditions. The area fraction of void increased with increase of test temperature, stress, and load holding time. In case of internal defect presence, micro-voids initiated in the early stage of loading period and resulted in the increased load line displacement and crack growth rate. The microvoids were found to form along the prior austenite grain boundaries and at the martensite packet boundaries.

Burst Cause Analysis of the High Temperature Steam Pipe in Heavy Oil Well

2014 ◽  
Author(s):  
Qiang Liu ◽  
Sheng-yin Song ◽  
Yao-rong Feng ◽  
Bo Duan
Keyword(s):  
High Temperature ◽  
Brittle Fracture ◽  
Fracture Surface ◽  
Heavy Oil ◽  
Mechanical Damage ◽  
Water Hammer ◽  
Oil Well ◽  
Damage Area ◽  
Steam Pipe ◽  
High Temperature Steam

The high temperature steam pipe used in one heavy oil well in China burst. This failure pipe was investigated and analyzed by macroscopic analysis, material tests (including chemical composition, metallurgical analysis & mechanical property) and fracture surface scanning electronic microscopy (SEM) analysis. Then it can be concluded that the mechanical properties of the burst pipe accord with related standards, and that the fracture surface is a typical brittle fracture. The herringbone stripes were found on the fracture surfaces and pointed to a fracture source where there were over 1.6mm deep mechanical damages on the pipe surface. After micro hardness testing near mechanical damage area and the nearby substrate, it was found that the toughness of mechanical damage area was low. The expanding diameter of the burst pipe was also investigated. Because the residual water in the pipe was pushed by high temperature steam when the steam was turned on, the speed of water was very fast, and the stress caused by water hammer were higher than yield pressure of the pipe, which is the internal pressure in the pipe and which could produces a maximum hoop stress in the pipe equal to the yield strength of the pipe material, the pipe would be expanded. The fracture surface is a typical brittle fracture. There are two mechanical damages on the fracture source, and the pipe burst because of the mechanical damages and huge impact of water hammer.

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