3.轴封系统, Gland Seal Steam System

设置在低压汽封供汽管路上的温度控制站自动调节以 保持低压汽封供汽温度的稳定。总之，从启动前投汽 封到停机后停止汽封送汽，该系统完全能自动调整， 具有良好的负荷适应性。 •The temperature control station at low pressure Gland Seal Steam steam supply pipeline automatically regulates, so as to maintain low pressure Gland Seal Steam steam supply temperature to be stable. In conclusion, from putting Gland Seal Steam into service prior to startup, till stopping gland seal steam supply after stoppage, this system can fully auto control, and can well adapt to loads.
轴封系统相关设备的简介
Gland Seal Steam System Relevant Equipments Brief Introduction
汽轮机组轴封系统采用具有自动调节装置（调整轴封 供汽压力）的闭式轴封系统。它由轴端汽封、供汽母管 压力调整机构、轴封加热器、轴封风机、蒸汽过滤器、 喷水减温器以及有关管道组成的闭式轴封系统。
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随着机组负荷的增加，调速汽阀开大，进汽量增加，汽缸内压 力相应增大。当高中压缸两端的排汽压力高于“X”腔室压力时， 汽流在内汽封环内发生相反流动，缸内的蒸汽经过汽封流向“X” 腔 室 。 With unit load increasing, speed governor valve open larger, steam inlet more and more, turbine casing inside pressure increase accordingly. When exhaust pressure of high pressure/intermediate pressure 2 ends is > “ X ” chamber pressure, steam contrarily flows inside inner Gland Seal Steam ring, steam inside casing passes through Gland Seal Steam and flows to “X”chamber. 当机组负荷升至25％额定负荷时，此时再热冷段已能满足全部汽 封要求，供气可以由再热冷段提供，也可以继续使用辅助蒸汽，供 气母管压力应达到0.127MPa。 When the unit load is up to 25％ of the rated load. the reheat cold section can meet all the gland steam supply requirement .then steam is supplied by the reheat cold section ,or continue to use the auxiliary steam , and maintain the steam supply main pipe pressure at 0.127MPa automatically.
•当负荷升至60％以上时，高压缸轴端漏入供气母管的蒸汽量超 过低压缸轴端汽封所需的供汽量，当蒸汽母管压力升至0.13MPa 时。所有供汽站的调节阀自动关闭，溢流站调节阀自动打开，将 多余的蒸汽通过溢流控制站排至排气装置。至此，汽封系统进入 自密封状态，汽封母管压力维持在0.13MPa，正常运行时应关闭 再热冷段管路上电动截止阀。 •When the load is increased to more than 60％,the quantity to steam leaked from HP cylinder shaft ends into the supply main pipe exceeds that required by the LP cylinder gland seal . When the main pipe pressure ascends to 0.130 Mpa (a), the control valves of all steam supply stations are closed automatically; the control valves in the overflow station are opened automatically and discharge the redundant steam to the exhaust device through the overflow control station. Up to this point, the turbine steam seal system enters into the self-sealing state and the pressure of main pipe maintains at 0.130 Mpa (a). During a normal operation, the electric check valve in the cold reheat pipe shall be shut down.
轴封系统流程图
Gland Seal Steam System Flow Chart
在汽轮机起动和低负荷时所有汽缸中压力都低于大气压力。密封汽供到“X” 腔室，通过汽封片一边漏入汽轮机，另一边漏到“Y”腔室。“Y”腔室与轴封加 热器相连，轴加风机抽吸此漏气，控制该室压力具有一定的真空度。 因而，外 界空气通过外部汽封片漏入“Y”腔室后，与从“X”腔室来的密封蒸汽混合，再 流向轴封冷却器。 When turbine starts and load is low, all turbine casing inside pressures are <atmospheric pressure. Seal steam supply to “X”chamber, through seal strip 1 side leak into turbine, another side leak to“Y”chamber. “Y”chamber connect with gland steam condenser, gland steam condenser fan sucks this leaked steam, and controls pressure and make this chamber has certain vacuity. Hence, the outside air leaks trough the outer seal strip into“Y”chamber, then, mix with the seal steam which is from “X”chamber, then, flows to gland steam cooler.
Turbine unit Gland Seal Steam system adopts closed Gland Seal Steam system which has auto-control device (control gland seal steam supply pressure). This closed Gland Seal Steam system is comprised of shaft end Gland Seal Steam, steam supply header pressure control mechanism, gland steam condenser, gland steam condenser exhauster fan, steam filter, water spray desuperheater, and the associated pipes.
波黑斯坦纳瑞1×300MW燃煤电厂 Stanari 1×wenku.baidu.com00MW Coal Fired Power Plant,
2016年3月16日 March 16th, 2016
轴封系统 Gland Seal Steam System
轴封系统的工作原理 Gland Seal Steam System Work Principle 轴封供汽系统采用自密封式，并有防止汽轮机进水而损 坏汽轮机的措施，轴封系统的供汽汽源满足机组冷、热态 启动和停机的需要。该系统设有轴封压力自动调整装置、 溢流泄压装置和轴封抽气装置等设备。 Gland seal steam supply system adopts self-seal, and has measures to prevent water entering into turbine and damaging turbine, steam supply source of Gland Seal Steam system meets requirements for unit cold/hot startup and stop. This system has Gland Seal Steam pressure automatic control equipments, overflow pressure relief equipments, gland steam extraction equipments, etc.
在启动过程中，汽源供汽经压力控制站调压稳压后，一部分向经 压力控制站调压稳压后，一部分向高、中压汽封供汽，另一部分经 喷水降温向低压汽封供汽；当机组达到一定负荷后，低压轴封用汽 完全由高、中压前、后汽封的漏汽供给，随着负荷继续升高，高中 压汽封的多余漏汽自动溢流到排气装置，并由汽封溢流控制站自动 保持供汽压力稳定。 •During startup, after pressure control station controls and stabilizes the pressure of steam supply, one part of steam supply for high pressure/intermediate pressure steam seal, another part of steam supply for low pressure steam seal after water spraying and desuperheating; When unit reaches a certain load, the steam for low pressure Gland Seal Steam is completely supplied by the steam leakage of high pressure/intermediate pressure front/rear steam seal, as load keep rising, the surplus leaked steam of high pressure/intermediate pressure steam seal automatically overflows to exhaust steam device, and the Gland Seal Steam overflow control station automatically maintains steam supply pressure to be stable.