标准编号:	DL/T 932-2019
中文名称:	凝汽器与真空系统运行维护导则
英文名称:	Guide of operation and maintenance for the condenser and vacuum system of power plant
行业分类:	DL    电力行业标准
发布机构:	国家能源局
发布日期:	2019-06-04
实施日期:	2019-10-1
标准状态:	现行
替代旧标准:	DL/T 932-2005 凝汽器与真空系统运行维护导则
翻译语言:	英文
文件格式:	PDF
中文字符数:	27000 字
翻译价格(元):	1890.00 元
交付时间:	付款后 1 个工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.



This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization—Part 1: Structure and drafting of standards.



Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this standard shall not be held responsible for identifying any or all such patent rights.



This standard replaces DL/T 932-2005 Guide of operation and maintenance of the condenser and vacuum system. In addition to a number of editorial changes, the following technical changes have been made with respect to DL/T 932-2005:



——The operation and maintenance requirements of vacuum pump are added;



——The main failure causes of vacuum pump are added;



——The operation and maintenance requirements of dual-backpressure condenser are added.



This standard was proposed by the China Electricity Council (CEC).



This standard is under the jurisdiction of DL/TC 07 Technical Committee on Power Station Steam Turbine of Standardization Administration of Power Industry.



This standard was firstly issued in 2005, and this edition is the first revision.



In the process of implementing this standard, the relevant comments and recommendations, whenever necessary, may be fed back to the Standardization Center of China Electricity Council (No.1, 2nd Lane, Baiguang Road, Beijing, 100761, China).



Guide of operation and maintenance of the condenser and vacuum system



1 Scope



This standard specifies the general principles and requirements for the operation and maintenance of surface water-cooled condensers and vacuum systems of steam turbine-generator units in power plants.



This standard is applicable to water condensing steam turbine-generator units.



2 Normative references



The following referenced documents are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.



GB/T 5248 Electromagnetic (eddy-current) examination of copper and copper alloy seamless tube

GB/T 7735 Steel tubes—The inspection method on eddy current test

GB/T 12969.2 Method of eddy current testing for titanium and titanium alloy tubes

GB/T 20878-2007 Stainless and heat-resisting steels—Designation and chemical composition

DL/T 561 Guide for chemical supervision of water and steam in thermal power plants

DL/T 581 Condenser tube rubber ball cleaning equipment and cooling water debris filter

DL/T 712 Guideline for the selection of condenser and auxiliary cooler tube materials in power plant

DL/T 794 Guideline for chemical cleaning of fossil plant

DL/T 1078 Performance test code on steam surface condensers operation



3 General



3.1 The design, manufacturing and installation organizations shall, in consideration of the implementation of this standard, create favorable conditions for the reliable and economic operation of condenser and vacuum system.



3.2 The following technical data shall be provided to the preparation of operation regulations for power plants:



a) Influence curve of the backpressure of the unit on turbine heat rate;



b) Influence curve of the backpressure of the unit on the power generation;



c) Off-design characteristic curve of condenser;



d) Operation characteristic curve of circulating water pump;



e) Variation curve between pumping equipment performance and cooling water temperature or working steam parameters;



f) Requirements for water quality indicators such as oxygen content in condensed water.



4 Operation and maintenance requirements



4.1 Condenser



4.1.1 The tightness of vacuum system shall be qualified.



4.1.2 The condenser shall be in good clean condition.



4.1.3 The cooling water flow shall meet the design requirements.



4.1.4 The steam pressure of shaft seal shall be normal.



4.1.5 The supercooling degree of condensate shall be qualified.



4.1.6 The heat transfer end difference of condenser shall be within the design range.



4.1.7 The condensate water quality shall be qualified.



4.1.8 The water level of hot well shall be normal.



4.1.9 The condenser pressure shall be measured with an absolute pressure gauge, and the pressure transmission tube for condenser pressure measurement shall be free of ponding.



4.1.10 After the overhaul of the unit is completed, the condenser and vacuum system shall be flooded for leak testing.



4.1.11 All welds on the condenser body shall be tight and leak-free.



4.1.12 The compensator connected with the condenser throat and the LP cylinder shall be tight and leak-free. When the rubber compensator is equipped with a water seal, the water seal shall be intact.



4.1.13 All connecting tube welds connected to the condenser body shall be tight and leak-free.



4.1.14 The steam side drain valve of condenser shall be tight and leak-free.



4.1.15 The cooling tube shall be free of perforation and leakage.



4.1.16 The expansion joint and weld between the cooling tube and the tube sheet of the water chamber shall be tight and leak-free.



4.1.17 The connection between condenser water level gauge and water level transmitter shall be tight and leak-free, so as to ensure normal water level control and water level indication.



4.1.18 The condenser water level switch shall operate reliably.



4.1.19 The condenser water level shall be within the normal working range.



4.1.20 The vacuum interlock protection shall be normal.



4.1.21 Appropriate anti-corrosion measures shall be taken for condenser water chamber and tube sheet.



4.1.22 The quality requirements of circulating cooling water shall meet the relevant requirements in DL/T 561, and the flow rate requirements of cooling tubes shall meet those specified in Annex A.



4.1.23 When the unit will be shut down for more than 3 days, the cooling water in the condenser water chamber and the condensate in the hot well shall be drained in time after the shutdown of the unit.



4.1.24 When the unit will be shut down for more than one month, the condenser shall be dried and maintained in time after the unit is shut down.



4.1.25 For the condenser with half-side cleaning function, the partition seal between each water chamber shall be tight and leak-free.



4.1.26 The pressure difference between high- and low-pressure condensers of dual backpressure condensers shall reach the specified value. The pressure difference between high- and low-pressure condensers is related to condenser heat load, cooling water temperature, cooling water flow and condenser working state. The condenser pressure difference under different boundary conditions and normal operation state of condenser is defined as a specified value, and supervision shall be strengthened during unit operation.



4.2 Circulating cooling water and rubber ball cleaning system



4.2.1 The circulating water pump shall work normally, and the flow and outlet pressure can meet the requirements of various conditions of the unit.



4.2.2 For the closed circulating cooling system, the cooling capacity of the cooling tower shall meet the design requirements.



4.2.3 The operating pressure difference between the primary strainer and the secondary strainer of circulating water shall not be greater than the specified value, and can ensure the water quality requirements.



4.2.4 The water chamber shall be kept clean to improve the heat transfer effect of the cooling tube and prevent sundries from blocking the cooling tube.



4.2.5 For the condenser water chamber with siphon function, a water chamber vacuum pump shall be installed. The water chamber vacuum pump shall operate reliably and extract the gas accumulated in the water chamber in time.



4.2.6 For condenser water chamber without siphon effect, the water chamber shall be fully exhausted during start-up and regularly exhausted during operation.



4.2.7 When the condenser is in normal operation, the inlet valve of circulating water shall be fully opened, and if necessary, the opening of the outlet valve shall be adjusted to meet the operation requirements of the system.



4.2.8 The rubber ball cleaning spring can be put into normally and work effectively, and its technical indexes such as rubber ball quality, ball throwing quantity, cleaning time interval, cleaning duration and ball collection rate shall conform to the relevant clauses in DL/T 581. For power plants with conditions, the cleaning interval and duration of rubber balls shall be determined according to the cleaning coefficient of cooling tubes.



4.2.9 The quality of circulating water shall be monitored and measured regularly, and effective measures shall be taken to ensure the quality of circulating water when necessary.



4.2.10 There is no obvious scaling on the inner surface of condenser cooling tube.



 

4.3 Condensate system



4.3.1 The condensate pump shall meet the requirements of flow and head of each load of the unit under frequency conversion operation or power frequency operation, and can operate normally under the condition of low water level of condenser without cavitation and vibration damage.



4.3.2 The strainer at the inlet of condensate pump (if any) shall be timely checked for blockage and cleaned. For the filter with automatic backwashing function, its function shall be ensured and put into operation frequently, so that the differential pressure of the strainer does not exceed the set value.



4.3.3 If the shaft seal of condensate pump adopts mechanical seal, the gap shall be adjusted to meet the requirements to prevent wear and tear, resulting in excessive gap. If packing seal is adopted, the sealing water and cooling water shall be adjusted moderately, and the packing shall avoid being too loose or too tight to avoid air leakage or excessive wear.



4.3.4 The flange, exhaust valve and steam trap on the section from the hot well to the inlet of the condensate pump shall be tight and leak-free.



4.3.5 The valve stem, flange and welds of its pipeline of the condensate recirculation valve shall be tight and leak-free.



4.4 Shaft seal steam system



4.4.1 The design of shaft seal steam system shall be reasonable, and the steam supply and return of shaft seal shall be smooth.



4.4.2 The steam inlet regulating valves of each shaft seal shall operate normally.



4.4.3 The steam supply parameters of shaft seal shall be adjusted in time according to the operating conditions to maintain the operation of shaft seal system under micro-positive pressure.



4.4.4 The fan of shaft seal heater shall work normally.



4.4.5 The water level of shaft seal heater shall be normal.



4.4.6 The height of water seal in drain U-shaped tube of shaft seal heater shall be reasonable.



 

4.5 Pumping system



4.5.1 The condenser vacuum breaker valve shall be tight and leak-free.



4.5.2 The vacuum pump and pumping equipment shall work normally.



4.5.3 The air pumping mode of dual backpressure condenser shall be arranged reasonably to avoid the mutual influence of air pumping systems between high and low pressure condensers.



4.5.4 The water level of steam-water separator of vacuum pump shall be normal.



4.5.5 The cooling water flow shall be adjusted to make the cooling water temperature of pumping equipment as close as possible to the design value.



4.5.6 The working fluid temperature of vacuum pump shall be reduced as much as possible.



4.5.7 Adequate cooling water flow and working fluid flow of vacuum pump shall be provided.



4.5.8 The vacuum pump heat exchanger shall be clean and free from dirt and blockage.



4.5.9 When conditions permit, the low-temperature water with lower temperature than circulating water shall be used as cooling water source of vacuum pump.



4.5.10 The water inlet pressure of the water jet air ejector shall be normal.



4.5.11 When the working water temperature of the water jet air ejector is higher than the normal value, the low-temperature cooling water shall be replenished to the water tank of the extractor in time.



4.5.12 Control the water level of the water tank of the water jet air ejector to be normal.



4.5.13 The working steam pressure of steam jet air ejector shall be normal. If reduced, the working steam inlet valve shall be properly opened to restore the rated value, or the working steam shall be switched to a steam source with higher pressure rating.



4.5.14 The drainage of steam jet air ejector shall be normal without cross flow.



4.5.15 The strainer in front of the air ejector nozzle shall be kept clean.



4.5.16 Check that the cooling water temperature, cooling water flow and cleaning coefficient of the intercooler of the multi-stage air ejector shall be normal.



4.6 Heater drainage and exhaust system



4.6.1 The operating water level of low pressure heater shall be normal.



4.6.2 The exhaust of low pressure heater shall work normally.



4.6.3 The emergency drain regulating valve shall work normally without leakage.



4.6.4 The steam turbine body drainage and pipeline drainage entering the condenser shall be closed during normal operation.



4.7 Low pressure (LP) cylinder of steam turbine



4.7.1 The middle surface of LP cylinder shall be flat without deformation, and tight without leakage.



4.7.2 The shaft seal clearance of LP cylinder shall meet the design requirements.



4.7.3 The safety valve of the LP cylinder shall be tight and leak-free.



4.7.4 The welds, valves and connecting flanges on the steam extraction tube of the heater in the negative pressure section shall be tight and leak-free.



4.7.5 The water spray desuperheating system of the LP cylinder shall work normally.



5 Operation monitoring and test



5.1 Operation monitoring parameters



5.1.1 All parameters listed in Table 1 shall be monitored during operation.



5.1.2 When the vacuum tightness index is unqualified, leakage test shall be carried out in time during operation, or the condenser shall be filled with water for leak test during shutdown and maintenance; when the condenser pressure is more than 15% of the design value under the assessment condition, the test for condenser heat transfer characteristic shall be carried out. The test measurement items shall at least include condenser pressure, cooling water inlet temperature, cooling water outlet temperature, condensed water oxygen content, vacuum tightness, circulating cooling water flow, heat load, condenser cleaning coefficient, heat transfer coefficient, etc.

Foreword i
1 Scope
2 Normative references
3 General
4 Operation and maintenance requirements
5 Operation monitoring and test
6 Operation optimization of cold end system
7 Vacuum system failure and its causes
8 Overhaul and maintenance
Annex A (Normative) Water quality requirements for condenser cooling tubes made of different materials
Annex B (Informative) Supervision curve of condenser operation characteristics
Annex C (Informative) Calculation of overall heat transfer coefficient of condenser

凝汽器与真空系统运行维护导则
1 范围
本标准规定了发电厂汽轮发电机组表面式水冷凝汽器和真空系统运行维护的一般原则及要求。
本标准适用于水冷凝汽式汽轮发电机组。
2 规范性引用文件
下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。
GB/T 5248 铜及铜合金无缝管涡流探伤方法
GB/T 7735 钢管涡流探伤检验方法
GB/T 12969.2 钛及钛合金管材涡流检验方法
GB/T 20878—2007 不锈钢和耐热钢 牌号及化学成分
DL/T 561 火力发电厂水汽化学监督导则
DL/T 581 凝汽器胶球清洗装置和循环水二次过滤装置
DL/T 712 发电厂凝汽器及辅机冷却器管选材导则
DL/T 794 火力发电厂锅炉化学清洗导则
DL/T 1078 表面式凝汽器运行性能试验规程
3 总则
3.1 设计、制造和安装单位要为实施本标准创造条件，为凝汽器与真空系统的可靠与经济运行创造有利条件。
3.2 发电厂编制运行规程时，应附有下列技术资料：
a) 机组背压对汽轮机热耗率的影响曲线；
b) 机组背压对发电功率的影响曲线；
c) 凝汽器变工况特性曲线；
d) 循环水泵运行特性曲线；
e) 抽气设备性能与冷却水温度或工作蒸汽参数的变化曲线；
f) 凝结水含氧量等水质指标要求。
4 运行维护要求
4.1 凝汽器
4.1.1 真空系统严密性合格。
4.1.2 凝汽器清洁状态良好。
4.1.3 冷却水流量满足设计要求。
4.1.4 轴封蒸汽压力正常。
4.1.5 凝结水过冷度合格。
4.1.6 凝汽器传热端差在设计范围内。
4.1.7 凝结水水质合格。
4.1.8 热井水位正常。
4.1.9 凝汽器压力用绝压表测最，凝汽器压力测量传压管无积水问题。
4。1.10 机组检修完成后，应对凝汽器及真空系统进行灌水检漏。
4.1.11 凝汽器本体上的所有焊缝严密无泄漏。
4.1.12 凝汽器喉部与低压缸连接的补偿器严密无泄漏，橡胶带补偿器设有水封时，水封完好。
4.1.13 与凝汽器本体相连的所有接管焊缝严密无泄漏。
4.1.14 凝汽器汽侧放水阀严密无泄漏。
4.1.15 冷却管无穿孔泄漏。
4.1.16 冷却管与水室管板胀缝、焊缝严密无泄漏。
4.1.17 凝汽器水位计及水位变送器的连接处严密无泄漏，保证水位控制和水位指示正常。
4.1.18 凝汽器水位开关动作可靠。
4.1.19 凝汽器水位应在正常工作范围内。
4.1.20 真空联锁保护正常。
4.1.21 凝汽器水室及管板应采取合适的防腐措施。
4.1.22 循环冷却水水质要求应满足DL/T 561中的有关规定，冷却管流速要求应满足附录A中的有关规定。
4.1.23 机组停运超过3天时，应在机组停机后及时排尽凝汽器水室中的冷却水和热井中的凝结水。
4.1.24 机组停运超过1个月时，应在机组停机后及时对凝汽器采取干燥保养措施。
4.1.25 具有半侧清洗功能的凝汽器，各个水室之间的隔板密封应严密不漏。
4.1.26 双背压凝汽器的高、低压凝汽器压力差值达到规定值。高、低压凝汽器压力差值与凝汽器热负荷、冷却水温度、冷却水流量及凝汽器工作状态相关，将凝汽器不同边界条件、正常运行状态下的凝汽器压力差值定义为规定值，机组运行时加强监督。
4.2 循环冷却水和胶球清洗系统
4.2.1 循环水泵工作正常，流量和出口压力能满足机组各种工况的需求。
4.2.2 闭式循环冷却系统，冷却塔的冷却能力应达到设计要求。
4.2.3 循环水一次滤网及二次滤网的运行压差不大于规定值，且能保证水质要求。
4.2.4 水室要保持清洁，以提高冷却管的传热效果以及防止杂物对冷却管的堵塞。
4.2.5 对具有虹吸作用的凝汽器水室，应装设水室真空泵，水室真空泵应动作可靠，及时抽出水室中聚集的气体。
4.2.6 对无虹吸作用的凝汽器水室，启动时水室应充分排气，运行中定期排气。
4.2.7 凝汽器正常运行时，循环水进口阀全开，必要时调整出口阀开度以满足系统运行要求。
4.2.8 胶球清洗装簧能正常投入且有效工作，其胶球质量、投球量、清洗时间间隔和清洗持续时间以及收球率等技术指标应符合DL/T 581中有关条款的规定。对有条件的发电厂，胶球清洗时间间隔和清洗持续时间应根据冷却管清洁系数确定。
4.2.9 对循环水水质应定期监督测量，必要时采取有效措施保证循环水水质。
4.2.10 凝汽器冷却管内表面无明显结垢。
4.3 凝结水系统
4.3.1 凝结水泵在变频运行或工频运行工况下，都应满足机组各个负荷的流量与扬程的要求，并能在凝汽器低水位情况下正常运行，且不发生汽蚀与振动损坏。
4.3.2 凝结水泵入口滤网(如有)应及时检查其堵塞情况，并清理干净。对于具有自动反冲洗功能的过滤器应确保其功能并经常投运，使滤网压差不超过设定值。
4.3.3 凝结水泵轴封采用机械密封的，应调整其间隙符合规定，防止磨损，造成间隙过大。采用盘根密封的，密封水与冷却水调节适度，所加的盘根应避免过松或过紧，以避免泄漏空气或过度磨损。
4.3.4 热井至凝结水泵入口段上的法兰、排气阀、疏水阀严密无泄漏。
4.3.5 凝结水再循环阀的阀杆、法兰及其管道的焊缝等部位严密无泄漏。
4.4 轴封蒸汽系统
4.4.1 轴封蒸汽系统设计合理，轴封供汽、回汽顺畅。
4.4.2 各轴封进汽调节阀动作正常。
4.4.3 根据运行工况及时调整轴封供汽参数，维持轴封系统微正压运行。
4.4.4 轴封加热器风机工作正常。
4.4.5 轴封加热器水位正常。
4.4.6 轴封加热器疏水U形管内水封高度合理。
4.5 抽气系统
4.5.1 凝汽器真空破坏阀严密无泄漏。
4.5.2 真空泵、抽气设备工作正常。
4.5.3 双背压凝汽器的抽空气方式布置合理，避免高、低压凝汽器之间抽空气系统相互影响。
4.5.4 真空泵的汽水分离箱水位正常。
4.5.5 调整冷却水流量，使抽气设备冷却水温度尽可能接近设计值。
4.5.6 真空泵工作液温度尽可能降低。
4.5.7 真空泵冷却水流量充足、工作液流量充足。
4.5.8 真空泵换热器清洁，无脏污、堵塞问题。
4.5.9 有条件的情况下利用温度低于循环水的低温水作为真空泵冷却水水源。
4.5.10 射水抽气器进水压力正常。
4.5.11 射水抽气器工作水温度高于正常值时，应及时向抽气器水箱补充低温冷却水。
4.5.12 控制射水抽气器水箱水位正常。
4.5.13 射汽抽气器工作蒸汽压力正常。如果降低，应将工作蒸汽进口阀适当开大以恢复到额定值，或者将工作蒸汽切换至更高压力等级的汽源。
4.5.14 射汽抽气器疏水正常，不串流。
4.5.15 保持抽气器喷嘴前的滤网清洁。
4.5.16 检查多级抽气器中间冷却器的冷却水温度、冷却水流量和清洁系数正常。
4.6 加热器疏水排气系统
4.6.1 低压加热器运行水位正常。
4.6.2 低压加热器运行捧气工作正常。
4.6.3 危急疏水调节阀工作正常，无泄漏。
4.6.4 进入凝汽器的汽轮机本体疏水、管道疏水正常运行时应关闭。
4.7 汽轮机低压缸
4.7.1 低压缸中分面平整无变形，严密无泄漏。
4.7.2 低压缸轴封间隙符合设计要求。
4.7.3 低压缸安全阀严密无泄漏。
4.7.4 负压段加热器抽汽管上的焊缝、阀门和连接法兰严密无泄漏。
4.7.5 低压缸喷水减温系统工作正常。
5 运行监测与试验
5.1 运行监测参数
5.1.1 运行中应对表1所列各项参数进行监测。
5.1.2 真空严密性指标不合格时，应及时进行运行中检漏，或者利用停机检修机会对凝汽器进行灌水检漏；凝汽器压力大于考核工况下设计值15％以上时，应进行凝汽器传热特性试验，试验测量项目至少应包括凝汽器压力、冷却水进口温度、冷却水出口温度、凝结水含氧量、真空严密性、循环冷却水流量、热负荷、凝汽器清洁系数、传热系数等。
5.1.3 凝汽器运行监督可参见附录B。
表1 运行监测参数
序号 测量项目 符号 单位 测点位置
1 凝汽器压力 pk kPa 第一排冷却管上300mm～900mm处
2 低压缸捧汽温度 te ℃ 汽轮机低压缸捧汽口
3 冷却水进口温度 tW1 ℃ 凝汽器冷却水进水管
4 冷却水出口温度 tW2 ℃ 凝汽器冷却水出水管
5 凝结水温度 tc ℃ 热井出水管
6 抽气口温度 tq ℃ 凝汽器抽气管
7 冷却水进口压力 p1 kPa 凝汽器冷却水进水管
8 冷却水出口压力 p2 kPa 凝汽器冷却水出水管
9 抽气口压力 pq kPa 凝汽器抽气管
10 凝结水流量 Gc t/h 凝结水泵出水管
ll 凝结水含氧量 O2 μg/L 凝结水泵出口
12 热井水位 L m 热井
13 真空泵工作液温度 tZY ℃ 真空泵冷却器热端入口
14 真空泵冷却水温度 tZS ℃ 真空泵冷却器冷端入口
15 真空泵工作液流量 Gzy t/h 真空泵工作液入口管
16 真空泵冷却水流量 Gzs t/h 真空泵冷却水入口管
17 射汽抽气器工作蒸汽压力 pSQ MPa 射汽抽气器蒸汽入口管
18 射汽抽气器冷却水温度 tSQ ℃ 射汽抽气器冷却水管
19 射汽抽气器冷却水流量 GSQ t/h 射汽抽气器冷却水管
20 射水抽气器工作水压力 pSS MPa 射水抽气器工作水入口管
2l 射水抽气器工作水温度 tSS ℃ 射水抽气器工作水入口管
22 射水抽气器工作水流景 GSS t/h 射水抽气器工作水入口管
23 凝结水电导度 KH μS/cm 凝结水泵出口
24 真空泵电动机电流 Izb A 真空泵电动机
25 循环水泵电动机电流 Isb A 循环水泵电动机
5.2 真空系统严密性试验
5.2.1 停机时间超过15天，应在机组投运后3天内进行严密性试验。
5.2.2 机组正常运行时，每月应进行一次严密性试验。
5.2.3 试验时，机组负荷应在80％额定负荷以上。
5.2.4 试验时应先关闭凝汽器抽气出口阀，应停运抽气设备，30s后开始记录，记录8min，取其中后5min内的真空下降值计算真空下降速度。
5.2.5 真空系统严密性要求见表2。
表2 真空系统严密性要求
机组容量
MW 真空下降速度
kPa/min
＜100 ≤0.40
＞100 ≤0.27
5.2.6 漏入空气量计算。
由真空下降速度按下式近似求出漏入的空气量：
(1)
式中：
Ga——漏入空气量，kg/h；
V——处于真空状态下的设备容积，m3；
△P——试验时间内的真空下降量，kPa；
△t——试验时长，min。
5.3 凝汽器传热特性试验
5.3.1 通过试验掌握凝汽器运行状况，明确提高凝汽器真空的途径。
5.3.2 机组大修前、后均应进行凝汽器传热特性试验。
5.3.3 机组运行过程中，如果凝汽器性能明显下降，应进行凝汽器传热特性试验。
5.3.4 要求试验期间凝汽器不补水，系统为正常运行方式，机组负荷稳定。
5.3.5 试验仪器仪表应符合DL/T 1078的有关规定。
5.3.6 试验测量项目见表1。
5.3.7 试验项目
5.3.7.1 冷却水流量
采用超声波流量计或其他装置测量冷却水流最。将当前测量值与制造厂提供的凝汽器变工况特性进行比较，校验冷却水流量是否达到设计要求。
5.3.7.2 凝汽器热负荷
凝汽器热负荷可采用下列方法之一计算：
a) 正平衡计算法：
Q＝Qs×(Hs—Hc)/1000＋Qa (2)
式中：
Q——凝汽器的热负荷，MW；
Gs——进入凝汽器的当量蒸汽量，kg/s；
Hs——进入凝汽器的当量蒸汽焓，kJ/kg；
Hc——排出凝汽器的凝结水焓，kJ/kg；
Qa——进入凝汽器的附加热负荷，MW。
b) 反平衡计算法：
Q＝Gw×cp×(tw2—tw1)/1000 (3)
式中：
Q——凝汽器的热负荷，MW；
Gw——进入凝汽器的冷却水流量，kg/s；
cp——冷却水比热容，kJ/(kg·℃)；
tw2——凝汽器冷却水出口温度，℃：
tw1——凝汽器冷却水进口温度，℃。
5.3.7.3 冷却水温升
△t＝tw2—tw1 (4)
式中：
△t——冷却水温升，℃。
5.3.7.4 凝汽器水侧阻力
△pw＝p1—p2 (5)
式中：
△p——凝汽器水侧阻力，kPa；
p1——冷却水进口压力，kPa；
p2——冷却水出口压力，kPa。
5.3.7.5 凝汽器汽侧阻力
△pq＝pk—pq (6)
式中：
△pq——凝汽器汽侧阻力，kPa、
pk——凝汽器压力，kPa；
pq——凝汽器抽气口压力，kPa。
5.3.7.6 传热端差
δt＝ts—tw2 (7)
式中：
δt——凝汽器传热端差，℃；
ts——凝汽器压力下的饱和蒸汽温度，℃。
5.3.7.7 过冷度
△tC＝ts—tc (8)
式中：
△tC——凝结水过冷度，℃：
tc——热井出口凝结水温度，℃。
5.3.7.8 总体传热系数
(9)
(10)
式中：
K——总体传热系数，kW/(m2·℃)；
A——凝汽器传热面积，m2；
△tm——对数平均温差，℃。
5.3.7.9 运行清洁系数
(11)
式中：
βc——运行清洁系数；
K0——冷却管基本传热系数，kW/(m2·℃)；
βt——冷却水进口温度修正系数；
βm——管材和管壁厚修正系数；
K0、βt和βm的计算方法参见附录C。
5.3.7.10 不同运行条件下凝汽器压力计算。对于某一给定的冷却水流速、冷却水温度和运行清洁系数，根据附录C计算该工况下的总体传热系数；再根据凝汽器试验热负荷或者制造厂提供的汽轮机组热平衡参数计算热负荷，并考虑机组运行状况予以修正。按式(12)计算凝汽器压力下的饱和温度。