磷酸污水处理旋流器耐腐蚀磨损材料研究

采用了料浆罐试验机，台架模拟和现场考核等方法，研制并筛选了磷酸污水处理旋流器耐腐蚀磨损材料，结果表明，本文研制的中温烧结碳化硅内衬陶瓷件具有成本低，耐磨蚀性好等优点，满足旋流器工艺要求，并优于Ｍｏ２Ｔｉ等材料。     

Numerical modeling of gland seal erosion in a geothermal turbine

Excessive erosion of the low-pressure rotor end gland seal of a 25 MWe geothermal turbine produced a partial loss of turbine vacuum that degraded cycle efficiency. This study used computational fluid dynamics (CFD) to identify the causes of erosion and the optimal steam seal system flow conditions for reducing the erosion problem. The predictions were based upon a numerical calculation using a commercial CFD code (Adapco Star-CD) to model the rotor end gland seal with a steam flow containing hard solid particles. The results confirmed that flow conditions play a major role in rotor gland seal erosion. By changing steam seal flow pressures to vary flow, it was confirmed that there is a threshold seal flow condition below which erosion does not occur, or is minimized. Optimizing the rotor end gland seal supply pressure and intercondenser pressure reduced the turbulent flow kinetic energy by 49%, with a corresponding decrease in the erosion rate of the rotor gland seal surface. The erosion rate is related directly to the particle velocity and turbulent flow kinetic energy. Recommendations are provided for adjusting the rotor end gland seal system to avoid erosion.     

浅谈葛洲坝水轮机的空蚀磨损与防护试验

葛洲坝水电站投产以来的运行情况表明:水轮机过流部件已遭到过机泥沙的明显破坏,给电站的检修带来了极大的麻烦.近年来,为了探索泥沙对水轮机的破坏规律,研究减缓含沙水流对水轮机过流部件表面的磨蚀破坏速度,电站做了多方面的努力,本文将简要介绍这方面的情况.     

Numerical analysis of erosion of the rotor labyrinth seal in a geothermal turbine

Excessive erosion of the labyrinth seal of a 110 MW geothermal turbine has been investigated. This study used computational fluid dynamics (CFD) and aims to identify one cause of erosion and a possible solution for substantially reducing it. The predictions were based upon a numerical calculation using a CFD model of the labyrinth seal with a water/steam flow containing hard solid particles and solved with a commercial CFD code: Fluent V5.0. The results confirmed the existence of flow conditions that play a major role in the rotor labyrinth seal erosion. Afterwards, the flow path was simulated with changes of rotor labyrinth seal geometry, which are indeed feasible of being implemented. The results confirmed that it is possible to reduce the erosion process by approximately 80% by incorporating a steam flow deflector in the fourth stage diaphragm, which changes the steam flow direction in the inlet zone to the rotor labyrinth seal channel, resulting in a reduction in steam volumetric mass flow and hard particle velocity by about 44%.     

The new era of the livestock production in Mongolia: Consequences on streams of the Great Lakes Depression

Mongolia, a landlocked country of the Central Asian plateau, is experiencing a significant modification of herding practices coupled with an increase in livestock numbers. These modifications lead to increasing impacts of grazing on the Mongolian steppes with major consequences on the waterbodies. We researched the impacts of grazing intensity on the streams of the Great Lakes Depression in northwestern Mongolia. We assessed the level of watershed and stream bank erosion and the type of vegetation structure. We calculated the livestock densities per watershed and linked them to the stream water discharge through a new metric (I_CU). I_CU was created as a function of cattle unit density and water discharge, having water discharge at a stream section reflecting its location in the drainage and therefore accounting for the surface area drained upstream. We measured also the major nutrients in the stream water and researched the causalities between the grazing and the impairment of watersheds and streams. Our results suggest that the increase of livestock numbers is reaching beyond the grassland and affecting the stream ecosystem. Two major impacts were highlighted by this study, 1) the extensive watershed and stream bank erosion and 2) the increase in concentration of suspended particles and orthophosphate in stream systems. When compared with past values from literature, our results show recent eutrophication of the streams compared to the pre-liberalization of the herding activity in Mongolia (before 1991). Consequently the continued uncontrolled increase of livestock numbers could threaten the conservation of the Mongolian waterbodies, with notable consequences on the life of the nomadic population of the Central Asian Plateau.     

白河堡水库枢纽工程溢洪道破坏机现分析

在对工程区基本条件、工程检测资料综合分析的基础上，对溢洪道的破坏机制进行了探讨，并提出了相应的对策及建议，为工程除险加固决策提供了合理、可行的依据。     

Hot erosion wear and carburization in petrochemical furnaces

High temperature alloy stainless steels used in olefins manufacturing furnaces are exposed to extreme environmental degradation processes inclusive of carburization, oxidation and hot erosion wear. A study was undertaken to understand the hot erosion wear phenomenon in relation to substrate composition, atmosphere, temperature, time and the influence of carburization. An erosion wear test rig was designed and constructed to simulate the wear degradation process up to 1200°C. Results have shown a surprising relationship between erosion wear rate and temperature for the most prominent stainless steel alloy used in the industry. A novel coating technology was developed for mitigation that enables the non‐line‐of‐sight application of protective macro‐coatings typically 1 to 5 mm in thickness. Stainless steel coupons treated with these macro‐coatings have exhibited an enhanced resistance to both oxidation and carburization. These macro‐coatings also provide superior hot erosion wear resistance as compared to the uncoated stainless steel. A thorough examination of the microstructure and micro‐mechanical properties of the coatings is presented. Targeted applications include petrochemical furnace fittings (return bends), thermo‐wells and transfer‐line‐exchanger (TLE) surfaces. Commercial furnace trials of the prototype products have been initiated with some prototypes in field trials for over 18 months. Results of both laboratory accelerated testing and field evaluation will be discussed.     

Effects of Alloying Elements on Microstructure and Erosion Resistance of Fe—C—Cr Weld Surfacing Layer

Effects of alloying elements on microstructure and erosion resistance of Fe-C-Cr weld surfacing layer have been studied. The experimental results show that increasing C and Cr content favors improving the erosion resistance of the layer, and the excessive C and Cr result in decreasing the erosion resistance at 90 deg. erosion. That Mo, Nb or Ti improves the erosion resistance of Fe-C-Cr weld surfacing layer is mainly attributed to increasing the amount of M7C3 and forming fine NbC or TiC in austenite matrix, but the excessive Mo, Nb or Ti is unfavorable. The addition of Mo, Nb and Ti in proper combination possesses stronger effect on improving the erosion resistance and the erosion resistance (εA) of Fe-C-Cr weld surfacing layer with fine NbC, TiC and M7C3 distributing uniformly in austenite matrix obviously increases to 2.81 at 15 deg. erosion and 2.88 at 90 deg. erosion when the layer composition is 3.05C, 20.58Cr, 1.88Mo, 2.00Nb and 1.05Ti (in wt pct).     

烟气轮机防护涂层的研究及应用

从烟气轮机的工况出发，提出了对烟机涡轮叶片防护涂层的要求，讨论了涂层的设计思想。介绍了可供烟机叶片使用的四种涂层：长城１号（Ｃ－１）、长城２号（Ｃ－２）、长城３号（Ｃ－３）及长城４号（Ｃ－４），包括它们的主要化学成分，金相组织、氧化性能、热腐蚀性能、室温及高温硬度、结合强度、冷热疲劳性能、动态性能及涂层均匀性。重点讨论了长城１号涂层的应用情况，顺便提及Ｃ－３涂层的应用，同时介绍了Ｃ－２及Ｃ－４的应用前景。     

瞬态薄膜冷却对降低身管烧蚀的初探

本文叙述了瞬态薄膜冷却在降低武器烧蚀方面的应用,为了探索这种技术的应用前景,首先从模拟试验着手,设计了弹道试验的模拟装置用以模拟射击过程中装药的点燃,弹丸的运动,火药气体对膛壁的传热,弹道试验同时进行测压、测速、测温、测径向烧蚀量.试验还设计了射击过程中液体在膛壁的瞬态成膜技术,提供临时的隔热层,以降低膛面温度,从而降低径向烧蚀量,模拟试验取得了在主要弹道诸元基本不变的前提下膛面温度下降30%烧蚀量下降50%以上的初步成效。