西安翻译公司.doc

电站机组高压加热器High-pressure Heater of Adipala Power Plant Unit 高加的作用是用汽轮机的抽汽来加热锅炉给水，以提高机组的热效率。高压加热器按安置形式可分为：倒置立式、顺置立式和卧式三大类。本工程高压给水加热器为卧式、U形管、双流程，水室采用自密封结构，共有三台，位于给水泵出口，承受给水压力，所以称为高压加热器。The high-pressure heater is intended to heat up the boiler feedwater by using the turbine extraction so as to improve the thermal efficiency of the unit. The high-pressure heater can be divided into three types according to the form of placement, i.e. inverted vertical type, cis-set vertical type and horizontal type. The high-pressure heater used in this project is a horizontal type of U-shaped tube and double passes. The water chamber is of a self-sealing structure. A total of three are established at the outlet of the feed pump to withstand the feedwater pressure, thus called the high-pressure heater. 一、高加技术参数I. Technical Parameters of High-pressure Heater 1.设备规范表6-2-1（加热器的编号按汽机抽汽压力由高到低排列）：1. Device specifications (Table 6-2-1) (the heater number is in descending order according to the turbine extraction pressure): 序号项目#8高加#7高加#6高加1压力降管侧压力降（MPa）0.090.10.07壳体压力降（MPa）0.040.0660.04壳体每段(蒸汽冷却段、凝结段、疏水冷却段)压力降（MPa）0.033/0/0.0070.034/0/0.0320.01/0/0.032设计管内流速（m/s）2.12.22.3管内最大流速（m/s）2.42.42.43有效表面积（m2）249024601520每段(蒸汽冷却段、凝结段、疏水冷却段)有效表面积（m2）231/2150.8/108.2202/1980/278129.8/1102.5/287.74换热率（kJ/hr.m2）5总换热系数(kJ/hr.m2)3051/14350/80282993/14324/97651758/14280/100846给水端差（）-1.7007疏水端差（）5.65.65.68加热器壳侧设计压力（MPa）7.35.52.4设计温度（）385/290350/270480/230试验压力（MPa）11.08.253.6壳侧压力降（MPa）9加热器管侧设计压力（MPa）373737设计温度（）290270230试验压力（MPa）55.555.555.5管侧压力降（MPa）10净重(kg)12746410830076944壳体净重(kg)286502833110100管束与管板净重(kg)733107054053550运行荷重(kg)13563611632883632充水荷重(kg)1482001323959111711疏水调节阀口径mm待定待定待定设计温度/压力（/MPa）290/7.3270/5.5230/2.412危急疏水调节阀口径mm待定待定待定设计温度/压力（/MPa）290/7.3270/5.5230/2.4表6-2-1Table 6-2-1No.Item#8 High-pressure Heater#7 High-pressure Heater#6 High-pressure Heater1Pressure dropPipe-side pressure drop (MPa)0.090.10.07Housing pressure drop (MPa)0.040.0660.04Pressure drop (MPa) at each section of housing (steam cooling section, condensing section, drain cooling section)0.033/0/0.0070.034/0/0.0320.01/0/0.032Design flow rate in pipe (m/s)2.12.22.3Max. flow rate in pipe (m/s)2.42.42.43Effective surface area (m2)249024601520Effective area (m2) at each section (steam cooling section, condensing section, drain cooling section)231/2150.8/108.2202/1980/278129.8/1102.5/287.74Rate of heat exchange (kJ/hr.m2)5Total heat exchange coefficient (kJ/hr.m2)3051/14350/80282993/14324/97651758/14280/100846Terminal temperature difference () of feedwater -1.7007Terminal temperature difference () of drain 5.65.65.68On heater housing sideDesign pressure (MPa)7.35.52.4Design temperature ()385/290350/270480/230Test pressure (MPa)11.08.253.6Housing-side pressure drop (MPa)9Heater pipe side Design pressure (MPa)373737Design temperature ()290270230Test pressure (MPa)55.555.555.5Pipe-side pressure drop (MPa)10Net weight (kg)12746410830076944Housing net weight (kg)286502833110100Net weight (kg) of tube bundle and tube plate 733107054053550Running load (kg)13563611632883632Full water load (kg)1482001323959111711Aperture (mm) of drain regulating valve Indeterminate Indeterminate Indeterminate Design temperature / pressure (/MPa)290/7.3270/5.5230/2.412Aperture (mm) of emergency drain regulating valveIndeterminate Indeterminate Indeterminate Design temperature / pressure (/MPa)290/7.3270/5.5230/2.42.结构特性表6-2-2（高压给水加热器编号按汽机抽汽压力由高至低排列）：2. Structural characteristics (Table 6-2-2) (the high-pressure heater number is in descending order according to the turbine extraction pressure): 序号项目#8高加#7高加#6高加1加热器数量1112加热器型式 卧式U形管卧式U形管卧式U形管3加热器布置单列4壳体支撑固定+滑动5封头型式半球形封头材料SA516Gr706加热器壳体壳体最大外径及壁厚（mm）2280/902220/602220/60最大总长（m）11.43149.2最大操作间隔（m）79.34.7壳体材料SA516Gr70SA516Gr70SA516Gr70冲击板材料SA240Gr405SA240Gr405SA240Gr4057加热器管束加热器管侧流程222管子与管板的连接方式焊接胀接焊接胀接焊接胀接型式：弯管或直管弯管弯管弯管管子数量（根）290627882673管子材料（进口）SA556GrC2SA556GrC2SA556GrC2尺寸/壁厚*（mm）162.5162.5162.5备用管子*10%10%10%8水室与管板水室与壳体连结方式焊接焊接焊接水室材料SA516Gr70SA516Gr70SA516Gr70管板材料20MnMo20MnMo20MnMo短接管材料待定待定待定管板与水室连接方式焊接焊接焊接表6-2-2Table 6-2-2No.Item#8 High-pressure Heater#7 High-pressure Heater#6 High-pressure Heater1Number of heater1112Heater typeHorizontal U-shaped tubeHorizontal U-shaped tubeHorizontal U-shaped tube3Heater arrangement Single row4Housing supportFixed + sliding5Head typeHemisphericalHead materialSA516Gr706Heater housingHousing max. outer diameter & wall thickness (mm)2280/902220/602220/60Max. total length (m)11.43149.2Max. interval of operation (m)79.34.7Housing materialSA516Gr70SA516Gr70SA516Gr70Strike plate materialSA240Gr405SA240Gr405SA240Gr4057Heater tube bundleHeater pipe-side pass222Tube-tube plate connection Welding expandingWelding expandingWelding expandingType: elbow or straight pipe Elbow Elbow Elbow Number of tubes (unit)2,9062,7882,673Pipe material (imported)SA556GrC2SA556GrC2SA556GrC2Size / wall thickness * (mm)162.5162.5162.5Spare pipe *10%10%10%8Water chamber & tube plate Water chamber-housing connection WeldingWeldingWeldingWater chamber material SA516Gr70SA516Gr70SA516Gr70Tube plate material20MnMo20MnMo20MnMoNipple materialIndeterminate Indeterminate Indeterminate Tube plate-water chamber connection WeldingWeldingWelding* 每只高压加热器的外围管束（正对蒸汽流的）将采用更厚一些的管子。* The peripheral tube bundle (against the steam flow) will use some thicker tubes for each high-pressure heater. *指这部分管子堵去，仍不影响保证性能。* Blocking of this part of tubes will not affect the guaranteed performance. 二、高加结构特点II. Structural Characteristics of High-pressure Heater1、2 一 给水进、出口；3一水室；4一管板；5一遮热板；6一蒸汽进口；7一防冲板；8一过热蒸汽冷却段；9一隔板；10一上级疏水进口；1l一防冲板；12一U形管； 13一拉杆和定距管；14一疏水冷却段端板；15一疏水冷却段进口； 16一疏水冷却段；17一疏水出口1, 2 feedwater inlet & outlet; 3 water chamber; 4 tube plate; 5 heat shield; 6 steam inlet; 7 strike plate; 8 superheated steam cooling section; 9 partition; 10 inlet of upper level drain; 11 strike plate; 12 U-shaped tube; 13 draw bar & pipe spacer; 14 end plate at drain cooling section; 15 inlet at drain cooling section; 16 drain cooling section; 17 drain outlet图6-2-1 高加结构Figure 6-2-1 Structure of High-pressure Heater壳体是钢板焊接构件，为保证其焊缝质量，焊缝都经100%无损检查。壳体和水室是焊接连接。为了便于壳体的拆移，还安装了吊耳及壳体滚轮，并使其运行时自由膨胀。高压给水加热器壳体为全焊接结构，并按全真空与抽汽压力加强，能承受现有管道的推力和力矩。The housing is a steel plate welded component. All welding seams will be subject to 100% nondestructive inspection to ensure their quality. The housing and the water chamber are connected via welding. For easy removal of the housing, a lifting eye and housing rollers are installed which are free to expand during operation. The housing of the high-pressure heater is a fully welded structure and is reinforced according to full vacuum and extraction pressure. It is able to bear the thrust and torque of the existing pipeline. 高压给水加热器汽侧装设泄压阀，用于管子破损时保护壳体不受损，该泄压阀的最小排放容量为10%的给水流量或一根传热管完全断裂时，在内外压差的作用下，两个断口侧给水量的较大值。高压给水加热器的水侧装设泄压阀，用于当加热器的进水阀与出水阀关闭且汽侧存有抽汽时，保护加热器不会因热膨胀而超压。A pressure relief valve is mounted on the steam side of the high-pressure feedwater heater in order to protect the housing against damages in case of pipe breakage. The minimum discharge capacity of the relief valve is 10% of the feedwater flow, or the greater value of feedwater flow on both fractured sides under the effect of internal and external differential pressure in case a heat transfer tube is completely fractured. A pressure relief valve is also mounted on the water side of the high-pressure feedwater heater to protect the heater against overpressure due to thermal expansion when the heater inlet and outlet valves are closed and extraction is reserved on the steam side. 水室按外形分：圆柱形大开口水室、圆柱形小开口水室、半球形小开口水室。水室组件由半球形封头或圆柱形筒身和管板组成管板钻有孔，以便插入U形管。水室组件还包括给水进口接管、出口接管、排气接管、安全阀、化学清洗接头和引导水流按规定流动的分隔板以及带密封垫圈的人孔盖、人孔座或密封盖。Classification of water chamber by appearance: cylindrical large opening water chamber, cylindrical small opening water chamber, and hemispherical small opening water chamber. The water chamber assembly comprises a hemispherical head or cylindrical shell and a tube plate. The tube plate is drilled with holes for insertion of U-shaped tube. The water chamber assembly also includes feedwater inlet nipple, outlet nipple, exhaust nipple, safety valve, chemical cleaning joint and a partition that guides the flow as required, as well as manhole cover, manhole seat or sealing cap with seal washers. 钢制隔板沿着整个长度方向布置，这些隔板支撑着管束并引导蒸汽沿着管束按90度转折流过管子，隔板又借助拉杆和定距管固定，换热管经焊接和爆炸胀于管板上。在加热器里装置不锈钢防冲板，可使进入壳侧液体和蒸汽不直接冲击管束，以免管子受冲蚀。这些板都布置于壳体各进口处。管子的支撑板和挡板有足够的数量，以防止在所有运行工况下管子的振动，支撑板和挡板允许有自由滑动的裕度。The steel partitions are arranged along the entire length. These partitions support the tube bundles and guide the steam to flow through the tube by turning 90 degrees along the tube bundle. The partition is fixed with draw bars and pipe spacers. The heat transfer tube is welded and blast-expanded onto the tube plate. A stainless steel strike plate is mounted in the heater so that the fluid and steam on the housing side will not directly impact the tube bundle, thereby avoiding tube erosion. These plates are all arranged at the housing inlet. A sufficient number of tube support plates and baffles are provided to prevent tube vibration in all operating conditions. The support plate and baffle allow for margins for free sliding. 为提高效率，高加分为过热蒸汽冷却段、凝结段、疏水冷却段，过热蒸汽冷却段是利用从汽轮机抽出的过热蒸汽的一部分加热来提高给水温度的；它位于给水出口流程侧，并有包壳板密闭。采用过热蒸汽冷却段可提高离开加热器的给水温度，使它接近或略超过该抽汽压力下的饱和温度。To improve the efficiency, the high-pressure heater is divided into the superheated steam cooling section, the condensing section and the drain cooling section. The superheated steam cooling section is to increase the feedwater temperature by heating a part of the superheated steam extracted from the turbine. It is located on the pass side of the feedwater outlet and is tightly closed with a cladding plate. The superheated steam cooling section can increase the temperature of the feedwater that has left the heater so that is close to or slightly higher than the saturation temperature under this extraction pressure. 从进口接管进入的过热蒸汽在一组隔板的导向下以适当的线速度和质量速度均匀地流过管子，并使蒸汽保留有足够的过热度以保证蒸汽离开该段时呈干燥状态，这样当蒸汽离开该段进入凝结段时，可防止湿蒸汽冲蚀和水蚀的损害。The superheated steam entered from the inlet nipple flows evenly through the tube at appropriate linear speed and mass velocity under the guidance of a group of partitions. A sufficient degree of superheat is retained in order to ensure the steam is dry when it leaves this section. In this way, when the steam leaves this section and enters the condensing section, damages arising from wet steam erosion and water erosion can be avoided. 凝结段是利用蒸汽冷凝时的潜热加热给水的。一组隔板使蒸汽沿着加热器长度方向均匀地分布，起支撑传热管的作用。进入该段的蒸汽，根据气(汽)体冷却原理，自动平衡，直至由饱和蒸汽冷凝成饱和的凝结水，并汇集在加热器的尾部或底部，收聚非凝结气体的排气管必须置于管束最低压力处以及壳体内容易集聚非冷凝气体处。非冷凝气体的集聚影响了有效传热，因而降低了效率并造成腐蚀。The condensing section is to heat up the feedwater via the latent heat during steam condensation. A group of partitions allow the steam to evenly distribute along the heater length, playing the part of supporting the heat transfer tube. The steam entered this section is automatically balanced according to the gas (steam) cooling principle until it is condensed into saturated steam from saturated condensate and collected in the rear or bottom of the heater. The exhaust pipe which collects non-condensable gases must be placed at the part of the tube bundle where the pressure is the lowest and at the location in the housing where non-condensable gases can be easily collected. The accumulation of non-condensable gases affects effective heat transfer, thus reducing the efficiency and causing erosion. 疏水冷却段是把离开凝结段的疏水的热量传给进入加热器的给水，而使疏水温度降至饱和温度以下。疏水冷却段位于给水进口流程侧，并有包壳板密闭。疏水温度降低后，当流向下一个压力较低的加热器时，减弱了在管道内发生汽化的趋势。加热器疏水冷却段有足够的深度，当最低水位时保证水封不破坏。包壳板在内部与加热器壳侧的总体部分隔开，从端板和吸入口或进口端保持一定的疏水水位，使该段密闭。疏水进入该段，由一组隔板引导流动，从疏水出口管疏出。The drain cooling section is to reduce the drain temperature below the saturation temperature by transferring the heat of the drain which has left the condensing section to the feedwater which has entered the heater. The drain cooling section is located on the pass side of the feedwater inlet and is tightly closed with a cladding plate. When the drain has its temperature reduced and flows to the next heater of lower pressure, the trend of vaporization occurred in the pipe is reduced. The drain cooling section of the heater is of sufficient depth and can ensure no damages to the water seal at the minimum water level. The cladding plate is internally spaced from the overall part on the housing side of the heater. A certain drain water level is maintained from the end plate and the suction port or the inlet end, thus having this section confined. The drain enters this section and flows under the guidance of a group of partitions, and then is discharged from the drain outlet tube. 三、高压加热器性能III. Performance of High-pressure Heater 高压给水加热器按TMCR工况下管侧流量为基准，并留有10%的流量裕量。最大管侧流速根据阀门全开VWO工况确定以避免损坏管子。当有10%堵管时，仍能保证高压给水加热器的性能满足汽轮机组各工况给水加热的要求以及各工况下加热器疏水端差和给水端差的要求。The high-pressure feedwater heater should refer to the pipe-side flow in TMCR condition, with 10% of flow margin left. The maximum pipe-side flow rate should be determined in accordance with the VWO condition to avoid pipe damages. When 10% of the pipe is plugged, the performance of the high-pressure feedwater heater should still be able to meet the requirements for feedwater heating in various operating conditions of the turboset as well as the requirements for the terminal temperature difference of heater drain and feedwater in various operating conditions. 高压加热器壳侧压力降小于相邻两级加热器间压差的30%，每台高压加热器壳侧每段的压力降不超过0.035MPa。三台高加管侧总压力降小于0.3MPa。The housing-side pressure drop of the high-pressure heater should be less than 30% of the differential pressure between the heaters on the two adjacent levels. The housing-side pressure drop at each section of the high-pressure heater should not exceed 0.035MPa. The total pipe-side pressure drop of the three high-pressure heaters should be less than 0.3MPa. 高压加热器投入运行时，满足机组负荷变化速度的要求，并满足给水温度变化率在升负荷时能达到3/min，降负荷时能达到2/min，而不影响高加的安全和寿命。When the high-pressure heater is put into operation, it should meet the requirements for the rate of load change of the unit. The rate of change of feedwater temperature should be able to reach 3/min when the load increases and 2/min when the load decreases without affecting the safety and service life of the high-pressure heater. 疏水出口管内水速不大于1.2m/s，当加热器中的疏水为饱和疏水且水位不受控制时、其疏水管内水速不大于0.6m/s。The water speed in the drain outlet pipe should be no greater than 1.2m/s. When the drain in the heater is saturated drain and the water level is uncontrolled, the water speed in the drain pipe should be no greater than 0.6m/s. 高压给水加热器水侧能承受给水泵超速后跳闸最大转速时的给水压力和汽侧最大的温度及其温度波动，并留有相应的裕量。The water side of the high-pressure feedwater heater should be able to withstand the feedwater pressure at the trip maximum speed after feed pump overspeed and the steam-side temperature as well as the temperature fluctuations, with appropriate margin left. 高压给水加热器汽侧能承受如下运行参数，并留有相应的裕量：The steam side of the high-pressure feedwater heater should be able to withstand the following operating parameters and appropriate margin should be left: 1.高压给水加热器汽侧运行压力至少能承受汽轮机阀门全开(VWO)工况的汽机抽汽压力的110，并有相应的裕量，保证整个寿命期长期安全运行。#1高压加热器汽侧还考虑在中压联合汽门试验时，加热器汽侧泄压阀动作的情况。1. The steam-side operating pressure of the high-pressure feedwater heater should be at least able to withstand 110% of the turbine extraction pressure in turbine VWO condition and appropriate margin should be left to ensure long-term safe operation within the entire life. The steam side of #1 high-pressure heater should also take into account the actions of the pressure relief valve on the steam side of the heater during medium pressure combined valve test. 2.高压给水加热器汽侧的运行温度至少能承受(VWO)工况汽机抽汽温度，并有相应的裕量。2. The steam-side operating temperature of the high-pressure feedwater heater should be at least able to withstand the turbine extraction temperature in VWO condition, with appropriate margin left. 所有高压给水加热器在任何非正常工况下均能满意地运行。保证水室入口、管束入口、壳体内部等部件无过度磨蚀。并保证在所有负荷下能平稳运行，而且无过大的噪音、振动和变形。All the high-pressure feedwater heaters should be able to run with satisfaction in any non-normal operating conditions. Ensure that water chamber inlet, tube bundle inlet, housing inside and other parts are not prone to excessive abrasion. Make sure that the heater is capable of stable operation under any load and free of excessive noise, vibration and deformation. 为确保电厂的安全可靠，所有高压给水加热器及其附属装置能承受所有运行工况下可能出现的各种荷载的最不利组合。包括以下各种工况：To ensure safety and reliability of the power plant, all the high-pressure feedwater heaters and their auxiliaries should be able to withstand the most adverse combination of various loads that may occur in all operating conditions, including the following conditions: 1.高压加热器的内部和外部运行中出现的最高压力及其压力波动；1. Maximum pressure and pressu