未交工核电站工作中的水位计.doc

Level instrumentation works in Nuclear Decommissioning未交工核电站中工作的水位计 There are a number of Nuclear sites across the UK in the process of being decommissioned, one of which is Dounreay in north of Scotland. The UK nuclear industry is one of the leaders in this field, setting the standards and models for the processing, handling of large and difficult legacy equipment and processes at all levels of contamination, to ensure it is handled, transported and disposed of safely.在英国，有很多逐步走向退役阶段的核电站，位于苏格兰北部的Dounreay核电站就是其中之一 。英国是在核领域处于领先地位的国家之一。它制定了处理大而困难遗留设备和处理各种程度污染的标准和操作模式。保证了污染物能够安全的得到操作、运输和处理。 Decommissioning generates different types of waste, from conventional industrial wastes to hazardous materials, such as asbestos and radioactive materials. Waste which cannot be safely recycled is segregated and processed at site ready for transportation and further processing, storage or disposal. About 50 facilities on the site at Dounreay have a history that involved the presence of radioactive materials, and special controls are in place around these to contain radiation. The key to successful decommissioning is careful planning and risk assessment. This is designed to keep to a minimum the exposure of workers to radiological and other hazards to minimise the impact on the environment.未交工的核电站能够产生各种不同类型的从可转换的工业废料到危险材料的废物，例如石棉和放射性材料。这些废料不能够安全循环利用，在现场被隔离或者处理然后准备进行运输或者进一步处理，接着存放或者是销毁。在Dounreay 的现场大约有50 套设备有放射性，这些设备附近的特殊控制设备也含有放射性。这些核电站成功退役的关键在于小心地进行计划和风险评定。这样设计是为了使电站员工最小限度的接触到放射性物质，使其他危险品和放射性物质最小限度的对环境产生影响。 Process challenges Some items need packaging and shipping in approved transport flasks to storage and reprocessing facilities. The loading of these flasks involves radioactive materials being placed inside and then filled with water, which protects the contents during transport. This loading area is very hazardous and requires remote, robotically operated handling and carefully designed process control systems. The water filling requires precision, the flask needs to be filled right to the top, but stop any over-spilling of the water, as a water clean-up in the filling area is highly undesirable. Notice the water filler ( in figure 1) on the parked position for the rig, should the water level touch the forks and drip off. The measuring range for the radar at the top of the flask is only 0-180mm, and they need secure accurate measurement at this critical stage of the process. 处理中的挑战一些物品需要包装并运输到运输瓶中进行储存和进一步处理。放射性物质被装入这些瓶子中，然后注满水，在运输过程中，水起到保护这些物质的作用。瓶子里装这些物质的区域是非常危险的，这一区域的操作需要远程机器人操作，同时要求要有精心设计的控制系统。装入的水要求十分精确，瓶里的水要正好填到顶部，但是不能让水溢出。要注意在停止位置的水性填料口，水位的高度应该接触到音叉和下降管。在瓶顶部的雷达测量的范围只有0-180mm.在这一过程中，它们需要安全的精确的测量。 Radars are being used on a variety of applications An EMPHASIS approved non contact (or through air) VEGAPULS radar is being used for the continuous level measurement. VEGASWING has also been supplied a for the high level switch, a fail safe vibrating fork, also approved for use as it is classified as a simple device (no microprocessors). They have been specially engineered for the application by VEGA engineers working with the customer.雷达的各种应用VEGAPULS 雷达在持续的水位测量中得到应用，它属于不接触测量(或者是通过空气）进行测量。VEGASWING 通过一个高水位开关和一个不安全的振动叉构成，也被归类成为一个简单的设备（没有小处理器） 它们是被VEGA 的工程师和客户经过特殊的设计和安装后才进行了应用。 Round the bend The extensions to the VEGAPULS waveguide and antenna, as well as the VEGASWING tuning fork also has bends to enable them to reach as well as accommodate manoeuvring inside the filling area to carry out their tasks. Both devices were specially designed and fabricated for the application, they are mounted on a pivoting rig, which can be swung over prior to filling for level monitoring and swung back when the flask is lifted in and out. The radar electronics housing, which incorporates the microwave generator, is mounted well away from the container and hazardous area. The only radar parts inside the area are a stainless steel tube wave guide and a cone antenna (see figure 2) thus avoiding electronics exposure to radaiation. The microwaves, which carry out the measurement, are guided along the tube then transmitted and received back by the cone antenna at the end. The technology of VEGA radars has proven extremely capable and adaptable, with bespoke waveguides up to and over 8m. This configuration is employed in many industries; waste, marine, chemical and molten metal processing, where remote mounting of the radar is desirable for various reasons. VEGASWING offers a level switch point which is mm repeatable. It uses tuning fork based level switch, this consists of a small piezo-drive screwed to the back of the forks to produce the vibration needed to detect liquid. A cable runs up inside the tube to the electronics module in the housing, where the vibrating element is monitored and the switch output connected. The VEGASWING also had a bent tube design engineered to work with the filling arm and mount alongside the radar the tuning forks are also mounted in a protection cage in case of accidental damage during manoeuvring of the filling rig and flask.VEGAPULS 的天线和波导以及VEGASWING的音叉都能弯曲，这样就能够使它们在注水区进行工作，完成它们的任务。但是这两个设备都需要特别设计和装配。它们需要安装在一个旋转的装置上。当水位显示过满之前，它能够摆越。当瓶子被提起和提出的时候，它能够震荡。雷达电子外罩部分，包括波导发生器，安装在远离容器危险区域的位置。在这一区域内唯一的雷达组件是一个不锈钢波导管和一个圆筒形天线。（见图2），这样就避免电子元件接触到放射性物质。微波传递测量信号并导向给波导管，然后发送，最后在末端的圆形天线接收到测量信号。VEGA 雷达液位计的技术已被证明非常可行并有很强的适应性。波导显示能够达到和超过8m. 这种设备已经应用在很多工业领域。废物领域， 船舶领域以及化工和融钢过程当中。出于各种原因，这些领域都希望安装远程雷达。VEGASWING 提供了液位开关点，在这个点上，毫米可以复验。在液位开关的基础上，它应用了音叉。在叉子的背面有一个通过螺丝固定的小的压力驱动器。压力驱动产生振动，进而进行液体监测。在管子内部有根电线插入，并连接到雷达电子外壳里的电子器件部分。在那里能够监测到振动信号，液位开关输出信号。VEGASWING还有一个弯曲的管路设计，以保证和填充臂能够一同工作。这个弯曲的管路安装在雷达音叉附近，它也是安装在一个保护壳里以避免在操作填充钻机和瓶子过程中造成意外的损坏。 Technology explanationVEGAPULS Radar uses microwave pulses which transmit to, and reflect back from, the product surface. In this instance they travel initially inside a tube several metres long, before being transmitted through air, many non-contact systems would pick up too much noise and signal interference from the tube to offer the reliability and accuracy needed. As VEGA use pulsed radar with advanced ECHOFOX signal processing, all echoes are discrete in time and the software can be easily set-up to only measure, in this case, over a specific 180mm measuring range beyond the end of the cone antenna. Radars can measure over many metres beyond the antenna, still with very good accuracy and repeatability. The VEGAPULS radar level transmitter, originally assessed by Exida for SIL applications, was also independently assessed by Sellafield Ltd, as part of the EMPHASIS project to satisfy the NII. It is now deemed acceptable for this sensor to be deployed in suitable SIL1 applications for the UK Nuclear industry. More information, search on your browser for articles on VEGA EMPHASIS approved radars. VEGASWING is a universal liquid level switch. As it has no microprocessors, this allows it to be classed as a simple device thus making it suitable for many applications by the nuclear industry. By using an active element, it has an inherently fail-safe design, where power loss, damage, build-up or corrosion, will cause the switch to fail-safe. When it touches liquid, the vibrating tuning fork element is damped and it gives a switch output. This micro dynamic, solid state mechanical technology enables it to detect almost any type of liquid, without needing floats or linkages. It doesnt require the tuning with product level for set up, associated with solid state electrical level probes. It conforms to IEC 61508/11: SIL 2, there is also a remote self-test option for checking operational readiness. 技术解析VEGAPULS Radar 传递脉冲波导，在产品的表面反射回去。在这个过程中，波导在被传递到空气之前在管子内部已运行了几米的行程。很多不接触的系统将会收集噪音和信号干扰。这样就保证了信号的稳定和精确性。VEGA 运用脉冲雷达和 先进的ECHOFOX 信号处理，使所有回声及时分离，软件能够容易的进行测量设置。在这种情况下，180mm 多的测量范围已经超过了圆形天线的末端。雷达能够测到天线以上几米的范围，而且依然能够保证好的精确性和可复性。VEGAPULS 雷达液位传感器，最初由Exida 在回话干扰度的应用上进行使用。也被Sellafield 公司独立作为EMPHASIS 工程的一部分来满足NII. 现在它也注定作为英国核工业SIL 1 应用的一部分得到接受和认可。更多信息，请在浏览器上查阅更多关于VEGA EMPHASIS approved radars 的文章。 VEGASWING 是一个万能的液位开关。它没有微型处理器，这就使它被归类为简单设备，这样在很多核工业应用中，它就有很强的适用性。 它有主动的零器件，也附带不安全的设计，当电流失，损毁，内建和腐蚀时都能引起开关导出不安全的信号。当它接触到液体，振动的音叉元件受潮，它就将给开关输出信号。“solid state”力学技术能够使这个小型动态仪器检测各种类型的液体，而不需要通过漂浮和连接来实现。它和固态电子液位插头连接，不需要音叉的设置。 它遵循IEC 61508/11: SIL 2，这个液位开关还有一个远程自我检测的功能用来检验运行的水位读数。 Looking to the future VEGAPULS EMPHASIS approved radars look set to play a big part in the nuclear industry, both on decommissioning and any future new builds. The flexibility of non-contact devices and designs have helped with some key applications, as well as meeting the security of design, cost and engi