学生期末自我评价200字

　 there? After ignition, combustion should focus its attention on what? Reducing boiler hot loss measures? DC-what are the main characteristics of the boiler? Boiler steam after Bao Biwen how? when shutdown to control steam drum wall temperature difference? From a run standpoint, what are the main measures to reduce coal consumption for power supply? Talk about how to control the water level? Generator after splitting, 6KV why to promptly exit the standby power switch? Why the current transformer secondary side in the operation are not allowed to open? Why synchronous generator excitation circuit of the degaussing switch can be changed into a lively breaker? Generator step-up process, why the rotor and stator currents to monitor? Why are rotor one point ground prone to 2nd after ground? Try 380V discussed following the grounding of auxiliary power system, wiring for three-phase five-limb terminal of PT secondary voltage change? Generator incomplete phase operation principle is what? Yn,d11 (Y0/-11) connection of generator-transformer systems, generator open-phase running any help? Why to install 100% stator grounding protection for large generator? Why does not allow running secondary short circuit? Generator excitation, excited, what is the of the overexcitation limit? Generator loss of excitation in the running, what is the impact on the system and the generator itself? Anti-cuozhong on the prevention of excitation system of generator caused by fault what damage? try discussing what are the measures of improving power system dynamic stability? What is a switching operation of the electrical equipment? main content switching operation of power plants and power systems are there? Try discussing malignant electric misoperation, which misuse personal, most of the equipment? Switch service power fast cutting device in several ways? in the alternate to the State, the standby power switch refused to deal with? Try discussing switching operations should focus on preventing misoperation accident? New operation or after majorrepair of transformers why test? Try discussing steps measured with a Megger insulationresistance of electrical equipment? Lu method is used to find DC grounding considerationarewhat? when there are two point grounding with the polarity should be ... 1.600MW supercritical supplementary questions, blank mini disk can be divided into manual and two oil turbine; oil turbine disc wheel car, the turning speed of the rotor can be controlled at around 80~120 RPM (high speed), and it is fulfilled by controlling access to the oil-pressure turbine oil turning on/off and speed level. Medium-speed Coal mill explosion-proof steam from a wind room, _, _ separator casing into the ground to prevent the mill explosion in the process of starting and stopping. Mill load is to accept current signal to the coal control proportional pressure relief valve size, change of hydraulic accumulators and hydraulic cylinders, to achieve load changes. Sealed Air for coal pulverizer drive, Rod bearings, roller. Cold wind of a user with a sealed air blower air, sealed air, ground coal to a cold wind. Turbine sealing oil primary oil source is air-side seal oil pump, the first alternate oil sources (mainly alternative oil source) is the main oil pump of turbine. When the primary oil source failure, the first spare source automatic put into operation. Second alternate oil sources primary alternate supply AC electric sealing oil pump on the fuel tank, when the turbine speed is less than 2/3 rated speed or first alternate source failure occurs, the second spare source automatic switch. Third alternative oil source is provided by DC sealing oil pump. Main fuel tank exhaust throttle should be located 2 steel closing door operation handwheel locking is not allowed and obvious warning signs should be hung. Steam engine room caught fire, when it threatened to tank or fuel system, shall immediately destroy the vacuum emergency stop, and turn on the tank accident put the throttle, speed and control on oil should be appropriate, to ensure that the rotors lubricants are not interrupted before static. Shaft seal overflow overflow to #8 the low pressure under normal conditions, when #8 the low pressure overflow when the outage to the condenser. Sliding pressure operation of deaerator may avoid deaerator steam source for throttling losses. Normal operation of steam turbine steam distribution mode for steam distribution nozzle. After the turbines stopped, if the rotor cannot rotate for a short time, rotor _ __ under bending, highest in __ ___ highs at this point rotor should be reset, close the hydrophobic __ __ cylinder, keeping __ up and down temperature difference between cylinder _ monitor rotor __ __ deflection, when after you verify that the rotor is, and then manually turning 180 o. When turning the motor over current or rotor disc doesn't move, do not forcibly barring ___ __, but can not turn __ forced _ or turning the crane broke. Stop turning _8__ hours later, to stop the lube oil system. Condensate pumps due to transportation of saturated water, the pump is most prone to cavitation __ ___, therefore is composed of __ inducer __, and at the time of installation ensure the pump inlet has some highly ____ __ intrusion, and design _ export recycled __ tubes, also in order to solve this problem. When the condenser when the water level is too low _ setting up __ pumps are turned on, into the air to prevent the pump design __ ___ seal water, prevent the pump output is not normal. ... Threaded tube within a water wall, deterioration of heat transfer does not occur. X turbine cold starts, heat transfer of steam to the cylinder wall is based on condensation heat transfer and convective heat transfer in two ways at the same time. (X) the furnace higher excess air coefficient, smaller chemical heat loss due to incomplete combustion. (√) Boiler of soda expansion is inevitable. √ Start-up incorporations, boiler-DC operation, adjustment of main steam temperature control in a coal-water ratio between points. √ A single swirl burner burning adjacent burners are not required to support. Swirl burners with different rotation direction will affect the boiler steam temperature and load parameters. X boiler steam flow is divided with double built-in startup separator designed for community process. √ During combustion of pulverized coal in boiler, oxygen content, the lower the NOx is produced more. √ When the gas-water ratio imbalances, once-through boiler steam temperature at each point in the trip will change, and closer to the pop tour entrance, inertia and hysteresis temperature change is smaller. √ In disguise near the heat transfer coefficient of steam increases to a maximum at first and then quickly lower. √ Control of start-up separator outlet steam temperature, that controls the boiler heating and evaporation, thermal heat distribution. (X) as the direct current requirements for operation of the boiler feedwater quality was much higher than that of drum boiler, in once-through boiler start-up process, therefore there is no need for furnace washing of Silicon. (×) UP the boiler is subcritical and supercritical parameters can be used in the furnace, working one or two times, connecting multiple hybrid, has a higher mass flow, suitable for large supercritical pressure once-through boiler. (X) this-is the biggest characteristic of evaporating heating surface of boiler tubes were repeatedly increased the vertical tube screen, using mixed header and not in the middle of heated drop tube in series to each other. Due to the temperature difference between different Panel next to the pipe, thermal stress, membrane water wall of seam damage. Check (√) the spiral water wall in addition to import and export is located outside the box, no mixing header in between, due to its arrangement of furnace size does not affect, even heat heat low errors will not result in the uneven distribution of steam-water mixture. (X) supercritical and subcritical case, when the water is heated to the appropriate phase transition temperature under pressure, all vaporize into steam. (X) direct current boiler, water into steam steam-water two-phase region does not exist. The experienced heating and hot water into superheated steam in two stages. (√) Phase transition under supercritical pressure, when all water vaporized into steam temperature, also known as the critical temperature. Different pressure phase transition temperature. (X) in the area near the phase transition point, the specific volume of refrigerant to rise sharply, and the greatest specific heat at constant pressure. (√) Under supercritical pressures, the specific heat of water increases with temperature, the specific heat of steam decreases with increasing temperature. (√) Under in subcritical once-through boiler evaporating heating surface of multiple values that appear unsteady flow, the main reason is a low enthalpy of evaporating heating surface inlet water. So in thelow-load operation must restrict entry low enthalpy of water. (X) the flowofrefrigeraevaporating heating surface of ambiguity existonlyinspiralwallverticatubecoilsdnotexist. √ Evaporation ...education and training. (3) technology can guide operators work on the business, ready to solve engineering problems. (4) the text clearly technical problems with the cards on the table and retain the original information to the persons concerned, good technical approval and visa in a timely manner. 4, data administrator responsibilities (1) is responsible for all the project files, data collection, production, binding, collating, storage (hand) and so on. (2) assist construction project "fuck" and other technical and engineering quality, safety, and education. (3) to help the staff disclosure of production technology, security technology, and collecting keep written information in a timely manner. (4) with the personnel concerned to carry out the measurement of quality and safety checks, and technical information. (5) according to the data, to the conservation section chiefs will report on the situation. Four job agencies, conservation management to achieve good conservation, achieve a standard, we must establish a sound management system, to ensure smooth progress. Under the unified leadership and management at different levels, to ensure that the concentration of decision-making power and unity of command, and a chain of authority, management at different levels; Division of labor and cooperation, so that the working groups towards the direction of professional development to ensure corporate goals and conservationComponent objectives of coordination, collaboration on the various functions of the body in action, coordination between the functional departments and managers, the entire management organizations to ensure that capable, efficient, multi-functional. Under the Chongqing Municipal landscaping management standards and the technical specifications of urban landscaping projects adopt the following approach working mechanism. Will this unit dedicated to the conservation section is divided into four groups: the trees and shrubs to the conservation group (responsible for measures such as the shading); full-time mechanical maintenance group (responsible for watering, cooling, spray during the day), lawn maintenance groups and plant groups. Section with garden plant professional engineer 1, each equipped with the professional technician 1, 2 technicians, carry out their duties. By the Resident Engineer of the conservation section chiefs and marketing grasp work and coordination. After five, lawn maintenance and management of plant construction, often with a 1-2 lawn maintenance can grow into the fullness of the week. After the lawn grow, but also to carry out regular maintenance and management, to ensure the lawn landscape continues for a long time. Lawn maintenance management including: irrigation, fertilization, pruning, weeding and other links. 1, irrigate irrigation lawn fertility environments can be improved, adding water plant the lawn, is a guarantee of normal lawn. In view of the lawn during the growth season, lawn and the environment is in a State of flux, coordination of water and soil and improving the microclimate of the Center, water cannot be implemented according to a fixed pattern, following a number of technical points for reference. (1) the irrigation time growing season, according to the different periods of precipitation is extremely important and timely irrigation of different grass species. Can generally be divided into three periods: ① turned green before the rainy season. High temperatures during this period, transpiration, water requirements, and is one of the most crucial irrigation under soil water retention properties of strength and rainy periods during which Bush 2-4. ② largely ceased during the rainy season irrigation. Air humidity during this period, grass transpiration decreased soil moisture content has increased to a level sufficient to meet the needs of lawn growth. ③ to yellowing of the leaf after this period before the rainy season precipitation, evaporation is greater, while the lawn is still in a great stage of life activities, compared with the previous two periods, lawn water requirements increase at this stage, if not timely irrigation, not only affect the growth of grass, also causes yellow. At this stage, according to 4-5 of irrigation. In short, grass types, water requirements are different, you mustAccording to the climate conditions and plant species to determine irrigation of the lawn. About a day, when irrigation is better depends on irrigation. In theory, the same period as long as the amount of irrigation water is less than the infiltration capacity of the soil, irrigation all the time in a day. Then depends on the irrigation way. If intermittent intermittent spray or spray irrigation (high degree of atomization), irrigation is best with the Sun. Not only can add moisture, but also significantly improve the microclimate and photosynthesis and transpiration and gas exchange, facilitated the coordination of water, air, fertilizer and soil thermal and vegetative organs of root and root expansion, and could lead the entire transit storage of the plant material, breathing, lawns and lush. If using water, irrigation, and so on, should be watching season, early spring, late autumn around the heel as well and the rest take twilight as much. (2) irrigation irrigation quantity should be based on the soil, growing, grass and other factors to determine. General lawn growing season drought period, takes about a week to pay 20-40mm; vigorously growing lawn in the heat and severe drought situations, need to pay 50-60mm per week or more. In General, regardless of the method, should be irrigated more than once, each time less water, maximum surface runoff that just occurred. 2, fertilizing to maintain lawn dark green leaves, grows, portions must be fertilized. Lawn plants for leaf growth and blossom-free requirements, so nitrogen is more important, response to nitrogen fertilizer is the most obvious. Should be basic application in building lawn, lawn built in growing season required after applying fertilizer. Cold season grass dressing time is best in early spring and fall. After the first green, can play a role in facilitating the growth of second in spring, after the weather turned hot, you should stop dressing. Fertilization in autumn on 9, October. Applies fertilizer the time is late spring of warm-season grasses. In a month or 2 months of growing season to be caught up with fertilizer. Increasing the density of foliage, improve resistance to stepping on. Fertilizing should not be late for the last time in mid-September. 3, trim Pruning is the focus of lawn maintenance, but is the most intensive work. Trim control lawn height of the tillers, increasing the density of leaves, weeds and lawn neat and beauty. General lawn trimmed at least 4-5 times a year, prune and trim the number of height is related to two factors. Lower the cutting height requirements, pruning more times. Leaves of grass density and coverage also increases with the number of trim and more. It should be noted that in accordance with regular mowing the grass cutting height, when up to 1.5 times the height of the grass, trim twice times the maximum shall not exceed the specified height. 4, weed weed invasion will seriously affect the quality of the lawn, turf lost uniform and neat appearance and purpose weed and grass competition for water, fertilizer, race the Sun, so that objective grass growth decline, so weed is an essential part of lawn maintenance and management. The fundamental methods of weed prevention and removal is the rational management of water and fertilizer, grass growth promotion purposes, increase competitiveness with weeds, and multiple trim, suppress weeds. Case against weeds, in addition to using artificial "rejects", I also use chemical herbicides, such as killing dicotyledonous weeds with 2.4-d class; using ximajin, prometryn, Diuron, closed soil inhibited germination of weed germination or kill weeds; sterilant herbicide, Diuron, and other lawn or lawn weed control of updates. Herbicide use is complicated, effect change over a number of factors, improper use can cause great losses and therefore should be carefully tested before use and preparation, concentration, tools used should be responsible. 5, the pierced holes on the lawn of ventilation holes, aims to improve the ventilation of roots, soil moisture content, to improve the effect of fertilization. The work to improve the quality of turf plays an important role. General requirements for 50 points/m2, 15cmx5cm hole spacing and hole diameter 1.5-3.5cm, cave deep 8cm hollow Iron Rod man-tie hole available, we can use lawn punching machine (restore root aeration machine) purposes. Root cutting comb comb the grass on the lawn, remove excess grass, improve the quality of grass growth. Lawn with had larger load or often by load of role, soil harden, can used lawn vertical trim machine, with milling knife dug wide 1.5-2.0CM, and spacing for 25cm, and deep about 18cm of ditch, in ditch within fill into more hole material (as sponge soil), put dug of soil turned came, and put remaining soil shipped go, application efficient fertilizer, and fill broadcast grass seed, strengthening fertilizer management, lawn can soon growth complex strong. Six, green cultivation and management of the emergency remedy 1, strengthen of the seedlings increased planting more trees in drought resistance. In the right amount at the right time in growing with compost, irrigation, promoting tree growth, tree sugar accumulation of nutrients in the body and can enhance the tree's resistance. Autumn fertilization must be stopped as soon as possible, so as to avoid long, shoot too late lignification, anti-freeze. 2, protected crowns and roots. Filling pile of dirt at the root Crown after cold winter water is very effective, usually 20-30 cm tall pile of dirt and solid. 3, package. Before the winter with straw or rope ... The following points: ① to select agents, prevent plants from harm. II in the valid range should use low concentrations of pesticides. Should pay attention to using different medicaments to prevent pest resistance. ③ may use high pollution, high residues of drugs and interfere with each other, improve control. ④ plant protection practice must be performed to ensure that human and animal safety. Seven, plant maintenance and management standards (a), pruning standards: 1, hedge trimmer, plastic plants: plants with plastic requirements should be carried out in a shoot out 15cm trim, hedgerow should ensure the smooth, clear, distinct. After the summer, we finally look forward to short term bridge engineering practice. This practice is an essential part of the learning process. While, we will in internship of process in the on reality in the of bridge has more directly of contact and study, such on we of courses of learning certainly is favourable of, on the, through this internship everyone on yihou of work environment, and work content also has has deeper of understand, this on is careers employment of we for, undoubtedly will produced is big effect, we then of select will more of rational carefully. After the internship is over, I am very satisfied. This internship I learned as a people's pride of place in road and bridge in the future. It is under the efforts of generations of people in road and bridge, bridge construction in China has been developing by leaps and bounds. Construction of road and bridge engineering in China with large scale, high speed, technical level has been greatly improved, and in some areas they have leading positions in the world. For example the practice seen in Hangzhou Bay Cross-Sea Bridge and Sutong bridge and other heavy-weight works all reflect the strength of bridge engineering. But in spite of this, we would like to see my level of some shortcomings, such as innovation in bridge design, as in project organization and management, in architecture, for example on the use of new materials, which are in the construction of bridge engineering gap with advanced countries. After this internship, we are national 985 University students as outstanding reserve force of national highway and bridge specialty, our responsibility is great. You can't deny that bridge, Southeast University student component in the national counterparts are significant. So we are on the country's future has a great influence on the development of road and bridge construction, which requires that we now learn professional knowledge, with better expertise at a later time. I can't say this bridge we are failing, that our nation's roads and bridges is a failure, it is frog in the idea! but we don't succeed, say is failure to bridge education in Southeast University. This internship I learned a lot, and practice experience is difficult to explain with just two or three sentences. In order to describe well, I order writing my practice report by practice date.8.20 is the first day of practice, rode through Hangzhou Bay Cross-Sea Bridge，Much world attention. Beginning of the construction of Ningbo Municipal Government explicitly proposed bridge project in accordance with the "three top objectives" standard to implement. Facing a complex build environment, challenging projects, organize and manage the bridge is placed in front of the headquarters of the great challenges. Many construction jobs, long front, existing synchronization job, cross process, the construction organization， After you come down from the Cross-Sea Bridge, and then we went to Shi Tang Heng Jiang bridge construction site. Ten Tang Heng Jiang bridge as a significant landscape bridge in Ningbo Hangzhou Bay new zone, very beautiful for the design. Questions: 1, twin rectangular structure to ensure a concrete casting in dense, according to General Manager of field projects, rectangular structure the concrete pouring is not guaranteed in full density, can only be detected later. He referred to the detection of three things: one is the use of ultrasonic testing, the other is the pouring of the concrete volume compared with the volume of rectangular components. In late testing, structure evaluation of housing a grade. Only the lower level again when pouring but in order to achieve a better effect of pouring, a self-compacting concrete was used by the project. 2, twin tower structure in balance. To this end they expert with Tongji University Tower design with a balanced system.

　Later in the course of the project PPT presentation, we also understand the characteristics and difficulties of the project, cause I'm more interested in is the construction of steel structure of main tower. The perimeter of the main tower made of welded steel plate, after steel plate welded into the rectangle and then pouring concrete. During construction of the main tower, construction unit went out on loan from 31 heavy industry group for hoisting two large-tonnage crane machines. Construction of steel structure of main tower is by sections, each segment the weight shown in the table below, we can see the difficulty of construction. Large sections of the Tower weightIn ten Tang Heng bridge watch during our first so directly contact with the bridge in construction State. This allows us to have a deeper feeling. First, as a bridge with the landscape, its design was more brilliant, two tilt Bridge viewed from the distance and rely on each other when the main tower structure, turned out to appear in the scene, we will issue voice of praise. We walked to the nearby looking at more than 80 metres from the main tower, it's tall and stands in contrast to our small and. I was for the first time this kind of bridge-building technology, both design and the construction of tracks! 8.21: the first task of the day is to go to Hangzhou subway tunnel excavation site. We walked about a kilometer from the tunnel into the distance to the under construction section. Because only a temporary erection of the access tunnel is a narrow way, so we are basically does not go without interruption all the way. We never made much. Today's second task is to watch the new intersection of Tang Lu Jingfang road connection of underground space engineering. Underground space connection project of xintang Lu Jingfang road intersection in new pond road intersects with Fengqi road junction road, Fengqi road along the new road direction setting. Construction of engineering structures using open-cut method. Works for the underground two-layer double-or two-story three-Bay rectangular frame structure, retaining structure with diaphragm wall, wall thickness 800mm. Support standard first line of concrete support + 4 steel support, first concrete support the shield section + 4 steel support (the 5th double steel backing for support). Main standard pit depth 16m depth of end well in Foundation pit of 17.5M. Subsidiary structure in total 9 entrance and 3 Wind Pavilion. According to this there is a project of urban underground space engineering features and difficulties. I are as follows: 1 the pipeline: the works surrounding the main gas, electricity, light current, water supply and other important pipelines, pipeline Manager Basic and parallel to the pit, part of a pipeline crossing the pit needs to be protected. 2, pit monitoring: this works on both sides of the Community traffic, and many surrounding buildings, five farmers ' markets in particular distance near pit, strictly controlling deformation of Foundation pit by the Department for this project, the monitoring of Foundation pit. 3, unearthed in the pit: as the project is located in the city center, excavation of large earth-moving required when shipping, this is subject to reasonable arrangements planned and coordinated work on the outskirts of unearthed. 4, traffic: the project covering 7 traffic organization during construction, the project has been completed the main structure of a traffic organization and Fengqi road traffic organization work. Transport organizations directly related to the project's construction progress.8.21: the first task of the day is to go to Hangzhou subway tunnel excavation site. We walked about a kilometer from the tunnel into the distance to the under construction section. Because only a temporary erection of the access tunnel is a narrow way, so we are basically does not go without interruption all the way. We never made much. Today's second task is to watch the new intersection of Tang Lu Jingfang road connection of underground space engineering. Underground space connection project of xintang Lu Jingfang road intersection in new pond road intersects with Fengqi road junction road, Fengqi road along the new road direction setting. Construction of engineering structures using open-cut method. Works for the underground two-layer double-or two-story three-Bay rectangular frame structure, retaining structure with diaphragm wall, wall thickness 800mm. Support standard first line of concrete support + 4 steel support, first concrete support the shield section + 4 steel support (the 5th double steel backing for support). Main standard pit depth 16m depth of end well in Foundation pit of 17.5M. Subsidiary structure in total 9 entrance and 3 Wind Pavilion. According to this there is a project of urban underground space engineering features and difficulties. I are as follows: 1 the pipeline: the works surrounding the main gas, electricity, light current, water supply and other important pipelines, pipeline Manager Basic and parallel to the pit, part of a pipeline crossing the pit needs to be protected. 2, pit monitoring: this works on both sides of the Community traffic, and many surrounding buildings, five farmers ' markets in particular distance near pit, strictly controlling deformation of Foundation pit by the Department for this project, the monitoring of Foundation pit. 3, unearthed in the pit: as the project is located in the city center, excavation of large earth-moving required when shipping, this is subject to reasonable arrangements planned and coordinated work on the outskirts of unearthed. 4, traffic: the project covering 7 traffic organization during construction, the project has been completed the main structure of a traffic organization and Fengqi road traffic organization work. Transport organizations directly related to the project's construction progress.During the on-site visit, we came up with some questions or deep or shallow. Q1: when we ask how to retaining of Foundation pit is dug out. Staff explained that it was out of the House a digging machine 60~