Modernization of Steam Turbine Diaphragms for the Saudi Aramco Gas Plants

TutorialThe critical components of the Saudi Aramco Uthmaniyah and Shedgum gas plants are eight trains of turbomachinery, 4 trains per plant. Each train consists of a steam turbine and a centrifugal compressor. At the time of their design and manufacture, these steam turbines were at their chronological level of technology. They operated reliably and effectively for their original design. However, during their 35+ years of operation, some of the diaphragms developed problems as the gas plants production gradually increased. With increased gas production, the mechanical strength of the heavily loaded diaphragms became marginal. As a result of the increased loading, these diaphragms deflected more than they did originally and caused axial rubs with serious diaphragm and rotor damage. Over the years as the operating conditions changed, Saudi Aramco personnel made several requests for the manufacture of “spare” diaphragms. Even though the operating conditions changed, the basic Saudi Aramco requirements did not. Specifically: -The diaphragms had to have adequate increased mechanical strength to withstand the increased loads. -They had to be more efficient. -They had to be a “drop-in” design which could be installed into the existing turbine without any rework of the case and rotor. At each request, diaphragm design changes were made to produce diaphragms that met Saudi Aramco’s requirements. Each design step exemplified the latest technology available at the times of their design and manufacture. This paper describes the design and manufacturing evolution leading to the current diaphragm design. The advanced analytical tools (FEA for defining stresses and deflections) were used for evaluating the mechanical integrity of the various diaphragm designs. Design improvements (vane profile, tangential vane lean, tip and new shaft seals), and manufacturing improvements (electron beam welding, laser and water jet cutting, electric discharge machine wire cutting), which have led to substantial gains in mechanical strength, efficiency and reliability will be described in detai

Modernization of Steam Turbine Diaphragms for the Saudi Aramco Gas Plants

TutorialThe critical components of the Saudi Aramco Uthmaniyah and Shedgum gas plants are eight trains of turbomachinery, 4 trains per plant. Each train consists of a steam turbine and a centrifugal compressor. At the time of their design and manufacture, these steam turbines were at their chronological level of technology. They operated reliably and effectively for their original design. However, during their 35+ years of operation, some of the diaphragms developed problems as the gas plants production gradually increased. With increased gas production, the mechanical strength of the heavily loaded diaphragms became marginal. As a result of the increased loading, these diaphragms deflected more than they did originally and caused axial rubs with serious diaphragm and rotor damage. Over the years as the operating conditions changed, Saudi Aramco personnel made several requests for the manufacture of “spare” diaphragms. Even though the operating conditions changed, the basic Saudi Aramco requirements did not. Specifically: -The diaphragms had to have adequate increased mechanical strength to withstand the increased loads. -They had to be more efficient. -They had to be a “drop-in” design which could be installed into the existing turbine without any rework of the case and rotor. At each request, diaphragm design changes were made to produce diaphragms that met Saudi Aramco’s requirements. Each design step exemplified the latest technology available at the times of their design and manufacture. This paper describes the design and manufacturing evolution leading to the current diaphragm design. The advanced analytical tools (FEA for defining stresses and deflections) were used for evaluating the mechanical integrity of the various diaphragm designs. Design improvements (vane profile, tangential vane lean, tip and new shaft seals), and manufacturing improvements (electron beam welding, laser and water jet cutting, electric discharge machine wire cutting), which have led to substantial gains in mechanical strength, efficiency and reliability will be described in detai

On the Superiority of the University of Arizona's Physics Club

We present an analysis on Physics Club's supremacy over the Astronomy Club at the University of Arizona. Through a thorough investigation of each club's history and content, and subsequent diligent calculations, we have proven without a doubt that the Physics Club is superior to Astronomy Club.Comment: 3 pages. Happy April Fools Da

Piezochemistry of reactions in solution

Bibliography: p. 215-222

Stress corrosion cracking of aluminum structural alloys and statistics of failure

Stress corrosion cracking (SCC), a premature failure mode due to the synergistic action of sustained tensile stresses and aggressive environment, is commonly observed in aircraft structural materials. The breaking load method has shown considerable promise as an accelerated test for quantifying SCC in terms amenable to interpretation using statistics and fracture mechanics. This method was employed to investigate development of SCC damage in alloy 2024 in naturally aged (T3) and artificially aged conditions (T8). The statistical procedure for data analysis, based on analysis of variance (ANOVA) methods, was applied to evaluate the effects of test parameters on experimental results. Corrosion damage in these alloy tempers was measured by comparing the post-exposure fracture stress of short transverse tensile specimens with the original tensile strength. Specimens were exposed to 3.5% salt water alternate immersion at various stress levels and time intervals. Experimentally determined fracture stress versus flaw size variations were compared to analytical results. A model based on a single semi-elliptical flaw geometry allowed prediction of maximum flaw depth from post-exposure fracture stress data. Breaking load test results are further interpreted in terms of their potential applicability for durability assessment of structural components. Resistance to cracking in AA 2024-T351 was improved significantly when specimens were coated with the Fluid Film\sp\circler corrosion preventive compound. The effect of alloy microstructure on SCC resistance is also discussed

Case Study 3: Curing A Booster Pump Joint Face Leak

Case Stud

Attenuating the rate of total body fat accumulation and alleviating liver damage by oral administration of vitamin D-enriched edible mushrooms in a diet-induced obesity murine model is mediated by an anti-inflammatory paradigm shift

Abstract Background Hypovitaminosis D is associated with many features of the metabolic syndrome, including non-alcoholic fatty liver disease. Vitamin D-enriched mushrooms extracts exert a synergistic anti-inflammatory effect. The aim of the present study is to determine the immunomodulatory effect of oral administration of vitamin D-enriched mushrooms extracts on high-fat diet (HFD) animal model of non-alcoholic steatohepatitis (NASH). Methods C57BL/6 mice on HFD were orally administered with vitamin D supplement, Lentinula edodes (LE) mushrooms extract, or vitamin D-enriched mushrooms extract for 25 weeks. Mice were studied for the effect of the treatment on the immune system, liver functions and histology, insulin resistance and lipid profile. Results Treatment with vitamin D-enriched LE extracts was associated with significant attenuation of the rate of total body fat accumulation, along with a decrease in hepatic fat content as measured by an EchoMRI. Significant alleviation of liver damage manifested by a marked decrease in ALT, and AST serum levels (from 900 and 1021 U/L in the control group to 313 and 340; 294 and 292; and 366 and 321 U/L for ALT and AST, in Vit D, LE and LE + Vit D treated groups, respectively). A corresponding effect on hepatocyte ballooning were also noted. A significant decrease in serum triglycerides (from 103 to 75, 69 and 72 mg/dL), total cholesterol (from 267 to 160, 157 and 184 mg/dL), and LDL cholesterol (from 193 mg/dL to 133, 115 and 124 mg/dL) along with an increase in the HDL/LDL ratio, and improved glucose levels were documented. These beneficial effects were associated with a systemic immunomodulatory effect associated with an increased CD4/CD8 lymphocyte ratio (from 1.38 in the control group to 1.69, 1.71 and 1.63), and a pro- to an anti-inflammatory cytokine shift. Conclusions Oral administration of vitamin-D enriched mushrooms extracts exerts an immune modulatory hepato-protective effect in NASH model